SHoC Network – Sonography in Hypotension and Cardiac-Arrest

The Sonography in Hypotension and Cardiac-Arrest (SHoC) Network is an international group of clinicians and researchers committed to advancing the evidence around the use of Point of Care Ultrasound (PoCUS) in critically ill patients.

The group evolved from a research network established by the International Federation for Emergency Medicine (IFEM) Ultrasound Interest Group, involving several PoCUS leaders from several international emergency medicine organizations.

The SHoC Network has been instrumental in initiating several research projects, as well as producing clinical guidelines. Further details are shown below.

Publications

The SHoC-ED study 2018 (SHoC-ED1) Link  Download

The SHoC systematic review of PoCUS in cardiac arrest Link  Download

The IFEM SHoC Consensus guidelines Link  Download

The SHoC-ED3 study – PoCUS vs No PoCUS in cardiac arrest Link  Download

The SHoC-ED-ECG study – does ECG predict cardiac activity? Link  Download

The initial SHoC study – clinical basis for protocol development Link  Download

Current Projects

The SHoC-ED2 study – PoCUS and ECG in cardiac arrest

The SHoC systematic review of PoCUS in hypotension

IFEM Documents and links

SHoC Guidelines link

IFEM PoCUS curriculum link

Network members and contributors include:

Paul Atkinson (Chair; 1,2,3),
David Lewis (1,2,3),
James Milne (4), 
Hein Lamprecht (5),
Jacqueline Fraser (1),
James French (1,2,3),
Laura Diegelmann (5,6),  
Chau Pham (7),
Melanie Stander (5),
David Lussier (7),
Ryan Henneberry (8),  
Michael Howlett (1,2,3),
Jay Mekwan (1,2,3),
Brian Ramrattan (1,2,3) ,
Joanna Middleton (1,2,3),
Niel van Hoving (5),  
Mandy Peach (1),
Luke Taylor (1),  
Tara Dahn (8),
Sean Hurley (8),
K. MacSween (8),
Lucas Richardson (8),  
George Stoica (9),
Samuel Hunter (10),
Paul Olszynski (11),
Nicole Beckett (12),
Elizabeth Lalande (13),
Talia Burwash-Brennan (14), K. Burns (15),
Michael Lambert (15),
Bob Jarman (16),
Jim Connolly (16),
Ankona Banerjee(1),
Michael Woo (14),
Beatrice Hoffmann (17),
Brett Nelson (18),
Vicki Noble (19)
1.     Department of Emergency Medicine, Dalhousie University, Saint John Regional Hospital, Saint John, New Brunswick, Canada
2.     Dalhousie Medicine New Brunswick, Saint John, New Brunswick, Canada
3.     Emergency Medicine, Memorial University, NL, Canada
4.     Family Medicine, Fraser Health Authority, Vancouver, BC, Canada
5.     Division of Emergency Medicine, University of Stellenbosch, Cape Town, South Africa
6.    Department of Emergency Medicine, University of Maryland Medical Center, Baltimore, USA
7.    Department of Emergency Medicine, University of Manitoba, Health Sciences Centre, Winnipeg, Manitoba, Canada
8.     Department of Emergency Medicine, Dalhousie University, QEII, Halifax, Nova Scotia, Canada
9.    Research Services, Horizon Health Network, Saint John Regional
Hospital, Saint John, New Brunswick, Canada
10. Faculty of Science, University of Ottawa, Ottawa, Ontario, Canada
11. Department of Emergency Medicine, University of Saskatchewan, Royal University Hospital, Saskatoon, SK, Canada
12. Department of Internal Medicine, Dalhousie University, Saint John
Regional Hospital, Saint John, New Brunswick, Canada
13. Department of Emergency Medicine, Université Laval, Québec, Québec, Canada
14. Department of Emergency Medicine, University of Ottawa, Canada
15. Department of Emergency Medicine, Advocate Christ Medical Center, Oak Lawn, IL, USA
16. Department of Emergency Medicine, Royal Victoria Infirmary, Newcastle upon Tyne, UK
17. Department of Emergency Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center, USA
18. Department of Emergency Medicine, Icahn School of Medicine at Mount Sinai, The Mount Sinai Hospital, USA
19. Department of Emergency Medicine, Case Western Reserve University, University Hospital Cleveland Medical Center, USA
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PoCUS assisted lumbar puncture

PoCUS assisted lumbar puncture

Resident Clinical Pearl (RCP) November 2019

Allyson Cornelis – PGY3 FMEM Dalhousie University, Saint John NB

Reviewed by Dr. Kavish Chandra

 

Lumbar punctures (LPs) are an essential emergency physician skill. Indications including assessing for serious causes of headaches such as meningitis and subarachnoid hemorrhage.

Various limitations to successful lumbar puncture include a large body habitus, arthritic spines, and altered spinal anatomy. Furthermore, this leads to increased procedural risks (failed attempts, pain, hematoma formation, infection and traumatic tap leading to difficult CSF interpretation)


Traditional lumbar puncture

The traditional way to perform a LP is using surface landmarks. The superior iliac crests are identified and a line is drawn across the back to connect them. This helps in identifying L3/L4 space. This is deemed a safe place for LP as the spinal cord ends above this.

 

PoCUS guided lumbar puncture

Ultrasound has become a common tool used in the emergency department for assessment of patients and to assist in certain procedures. Lumbar puncture is one procedure where ultrasound has potential to increase success.1,2

 

The evidence

Meta-analysis of PoCUS guided LPs in the ED with adult and pediatric patients showed improved success rates (NNT 11) and fewer traumatic taps (NNT 6), less pain and less time to obtaining a CSF sample.4

Similar studies in neonates and infants showed reduced LP failure and traumatic taps in the PoCUS guided LP group.5

 

The procedure

The goal of the LP is to place a needle into the subarachnoid space where the CSF can be sampled. At the safe level, LP needle moves in-between the caudal equina.

Adapted from Tintinalli’s Emergency Medicine : A Comprehensive Study Guide, 8th ed.

 

Landmark based LP (briefly)

Place the patient in the lateral decubitus or seated position, allowing them to curve their spine and open the space between adjacent spinous processes

Identify the superior iliac spines and connect a line between the two iliac spines across the back (this should intersect the L4 spinous process).

LP can be safely performed in the L3/4 or L4/5 interspaces. During the procedure, the needle is directed towards the patient’s umbilicus.

 

PoCUS guided LP2,3,6

Identify the midline

  • Position patient either sitting with a curved lumbar spine or laying down in a lateral decubitus position with back perfectly perpendicular to the table and not angled at all. Using either a linear or curvilinear probe (curvilinear is recommended for obese patients), in the transverse plane start at the sacrum which will appear as a bright white line.
  • Move the transducer towards the patient’s head while maintaining a transverse orientation. A space will appear followed by a smaller bright curved line with posterior shadowing, this is the L5 spinous process.

  • Center the spinous process in your screen, and mark the location with a surgical marking pen.

  • Continue moving the transverse transducer cephalad, you will see the interspaces (lack of spinous process and the accompanying shadow and possibly evidence of the articular processes which appear as bat ears).
  • Connect each mark identifying the spinous processes—this marks the midline of the spine

 

Identify the interspaces

  • Turn the transducer into the saggital plane with the indicator towards the patient’s feet (to line up the patient’s head with the view on the screen).

  • Place transducer along the spinal line you marked, starting at the top, and identify the spinous processes and the interspaces.
  • Place the interspace in the center of the transducer and mark with a line. Move caudally, identifying the remaining interspaces.

  • Connect these lines to your spinal line. Where they intersect are the ideal locations for needle entry.

 

The bottom line

Ultrasound is a tool being utilized more often in clinical practice, including in the emergency department. Research shows that its use in obtaining lumbar punctures has potential benefits, including more success in obtaining a CSF sample and less traumatic taps, with minimal harms or downsides to use of the ultrasound.

 

Copyedited by Kavish Chandra

 

Resources:

  1. Ladde JG. 2011. Central nervous system procedures and devices. In: Tintinalli JE, Stapczynski JS, Cline DM, Ma OJ, Cydula RK, Meckler GD, editors. Tintinalli’s emergency medicine: Acomprehensive study guide. 7th ed. China: McGraw-Hill Companies, Inc. p 1178-1180.
  2. Millington SJ, Restrepo MS, Koenig S. 2018. Better with ultrasound: Lumbar puncture. Chest 2018. 154(5): 1223-1229.
  3. Ladde JG. 2020. Central nervous system procedures and devices. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH, editors. Tintinalli’s emergency medicine: A comprehensive study guide. 9th ed. New York, NY: McGraw-Hill: http://accessmedicine.mhmedical.com.ezproxy.library.dal.ca/content.aspx?bookid=2353&sectionid=221017819. Accessed November 17,2019.
  4. Gottlieb M, Holladay D, Peksa GD. 2018. Ultrasound-assisted lumbar punctures: A systematic review and meta-analysis. Acad Emerg Med. 2019 Jan. 26(1). 85-96.
  5. Olowoyeye A, Fadahunsi O, Okudo J, Opaneye O, Okwundu C. 2019. Ultrasound imaging versus palpation method for diagnostic lumbar puncture in neonates and infants: A systematic review and meta-analysis. BMJ Pediatrics Open. 2019 Mar. 3(1):e000412.
  6. Jarman B, Hoffman B, Al-Githami M, Hardin J, Skoromovsky E, Durham S, et al. Ultrasound and procedures. In: Atkinson P, Bowra J, Harris T, Jarman B, Lewis D, editors. Point of Care Ultrasound for Emergency Medicine and Resuscitation. 1st ed. United Kingdom: Oxford University press; 2019. p. 198-199.
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Tardive Dyskinesia in an Emergency Setting

Medical Student Clinical Pearl (RCP) – October 2019

Faith Moore

Faculty of Medicine
Dalhousie University
CC3
Class of 2021

Reviewed and Edited by Dr. David Lewis



Case

A 48-year-old female was brought to the emergency department by EMS after developing dystonia that morning, a couple hours earlier, following a restless night. The dystonia had begun affecting her arms, torso and buccal region, but eventually moved to also involve her legs. She had a history of recurrent tardive dyskinesia for the past 20 years since taking stelazine and developing tardive dystonia. She was switched to olanzopine after developing dystonia and stayed on it until two months ago. Her citalopram and clozapam dosing had been increased two weeks ago, and she had also started Gingko biloba extract two weeks ago. She had started Nuplazid 3 days ago.

Upon exam she was diaphoretic with no other abnormal findings other than dystonia affecting the entire body.


Tardive Dyskinesia

Pathophysiology

    • Tardive dyskinesia is a hyperkinetic movement disorder that is associated with the use of dopamine receptor-blocking medications.1 The exact mechanism is under debate, but the main hypotheses include an exaggerated response by dopamine receptors due to a chronic dopamine blockade, oxidative stress, gamma-aminobutyric acid (GABA) depletion, cholinergic deficiency, altered synaptic plasticity, neurotoxicity and defective neuroadaptive signaling. 2 The most accepted theory of the mechanism is that the chronic dopamine blockade caused by the dopamine receptor-blocking medications results in a hypersensitivity of the receptors, specifically at the basal ganglia. 1
    • The medications that are known to have the possibility to cause tardive dyskinesia include antipsychotic drugs, anticholinergic agents (ex. Procyclidine), antidepressants, antiemetics (ex. Metoclopramide), anticonvulsants, antihistamines, decongestants (ex. pseudoephedrine and phenylephrine), antimalarials, antiparkinson agents, anxiolytics, biogenic amines, mood stabilizers and stimulants.1

Who is most at risk?

    • The medications that are the most common culprits are first- and second-generation antipsychotics and metoclopramide. The incidence of tardive dyskinesia from chronic first-generation antipsychotic exposure is 5-6% 3, and is 4% for second generation antipsychotics 4. There is no prospective research on chronic metoclopramide use and the risk for tardive dyskinesia at this point and time5, but a study in the UK in 1985 showed 1 case of tardive dyskinesia for every 35 000 prescriptions6.
      • Most prominent risk factors
        • Old age5
        • Chronic exposure5
        • Patients who develop extrapyramidal symptoms while on antipsychotic drugs.7

Signs and Symptoms

      • Repetitive involuntary body movements that may involve the face, tongue, eyes, arms, torso and legs

Diagnosis

    • The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) classifies tardive dyskinesia as “involuntary movements (lasting at least a few weeks) generally of the tongue, lower face and jaw, and extremities (but sometimes involving the pharyngeal, diaphragmatic, or trunk muscles), developing in association with the use of a neuroleptic medication for at least a few months” and that persists for at least one month after the medication is stopped.8

Differential Diagnosis

    • Acute dyskinesia
    • Akathisia
    • Parkinsonism and tremor
    • Perioral tremor
    • Stereotypies and mannerisms
    • Spontaneous or idiopathic dyskinesias
    • Isolated dystonia
    • Primary movement disorders
    • Chorea from systemic causes 9

Key Questions for History and Physical

    • Are the movements voluntary?
    • Is there an accompanied feeling of restlessness?
      • If yes, might point towards akathisia.
    • When did these movements began?
    • What is the body distribution of the involuntary movements?
    • Are there any extrapyramidal signs and symptoms?
    • Are there any associated features?
    • Have there been any drug changes in the past few months?

 

Management in the Emergency Department

    • First line treatment of tardive dyskinesia generally begins with discontinuation of the offending drug. In the emergency department this should be done after consulting with the treating physician. These patients are often being treated for psychiatric disorder and the treatment of the psychiatric disorder must be balanced with the risk of tardive dyskinesia. It may be appropriate to switch from a first generation antipsychotic medication to a second generation antipsychotic generation medication.
    • If the symptoms of tardive dyskinesia need to be treated, like in our case with this patient, there are various drugs that can be tried.
    • Tetrabenazine is considered first line.10
      • Suggested doses of 12.5-25 mg starting daily dose with a 25-200 mg/day dose range.10
    • Other treatment options
      • Dextromethorphan11
        • In a recent case study patients took under 1mg/kg, not exceeding 42 mg/day.11
        • This was recommended by a local neurologist here at the Saint John Regional Hospital.
      • Valbenazine 12
        • Suggested dose of 40 mg UID, increasing to 80 mg UID after one week.12
      • Amantadine10
        • Suggested dose of 100 mg starting daily dose with a dose range of 100-300 mg/day 10
      • Benzodiazepines12
        • Clonazepam initiated at 0.5 mg and titrated by 0.5 mg increments every 5 days to response up to a maximum dose of 3-4 mg/day. 12
      • Diphenhydramine suggested dose of 25-50 mg IV13
      • Botulinum toxin injections12
    • Commonly used treatments lacking evidence of efficacy
      • Benztropine10

Drug Starting Dose Recommendations Dose Range
1st Line
Tetrabenazine 12.5-25 mg UID 25-200 mg UID
Other options
Dextromethorphan Under 1 mg/kg Not exceeding 42 mg UID
Valbenazine 40 mg UID Increase to 80 mg after 1 week
Amantadine 100 mg UID 100-300 mg UID
Clonazepam 0.5 mg 0.5-4.0 mg UID
Diphenhydramine 25 mg IV 25-50 mg IV
Botulinum toxin injection local injection to treat specific painful dystonia resistant to systemic therapy

 


Case Continued

The patient was given 2mg of Benztropine IV with no effect. Twenty minutes later he was then given 1mg of Ativan SL with no effect. Thirty minutes later the patient was given 150 mg Benadryl IV, and some improvement was then witnessed, the patient was allowed to sleep and was discharged approximately 5 hours after his arrival with no symptoms.


External Resources

Treatment strategies for dystonia

Diagnosis & Treatment of Dystonia


References

  1. Cornett EM, Novitch M, Kaye AD, Kata V, Kaye AM. Medication-Induced Tardive Dyskinesia: A Review and Update.Ochsner J. 2017 Summer;17(2):162-174. Review. PubMed PMID: 28638290; PubMed Central PMCID: PMC5472076.
  2. Kulkarni SK, Naidu PS. Pathophysiology and drug therapy of tardive dyskinesia: current concepts and future perspectives.Drugs Today (Barc). 2003 Jan;39(1):19-49. Review. PubMed PMID: 12669107.
  3. Glazer WM.Review of incidence studies of tardive dyskinesia associated with typical antipsychotics. J Clin Psychiatry. 2000;61 Suppl 4:15-20.  PubMed PMID: 10739326.
  4. Correll CU, Schenk EM.Tardive dyskinesia and new antipsychotics. Curr Opin Psychiatry. 2008 Mar;21(2):151-6. doi: 10.1097/YCO.0b013e3282f53132.  PubMed PMID: 18332662.
  5. Rao AS, Camilleri M.Review article: metoclopramide and tardive dyskinesia.Aliment Pharmacol Ther. 2010 Jan;31(1):11-9. doi: 10.1111/j.1365-2036.2009.04189.x.  PubMed PMID: 19886950.
  6. Bateman DN, Rawlins MD, Simpson JM.Extrapyramidal reactions with metoclopramide. Br Med J (Clin Res Ed). 1985 Oct 5;291(6500):930-2. doi: 10.1136/bmj.291.6500.930. PubMed PMID: 3929968; PubMed Central PMCID: PMC1417247
  7. Novick D, Haro JM, Bertsch J, Haddad PM.Incidence of extrapyramidal symptoms and tardive dyskinesia in schizophrenia: thirty-six-month results from the European schizophrenia outpatient health outcomes study. J Clin Psychopharmacol. 2010 Oct;30(5):531-40. doi: 10.1097/JCP.0b013e3181f14098. PubMed PMID: 20814320.
  1. American Psychiatric Association, Medication-induced movement disorders and other adverse effects of medication, Diagnostic and Statistical Manual of Mental Disorders, fifth edition, American Psychiatric Association, 2013.
  2. Tarsy D, Deik A. Tardive dyskinesia: Etiology, risk factors, clinical features, and diagnosis. In: UpToDate, Eichler A (Ed), UpToDate, Waltham, MA. (Accessed on September 9, 2019.)
  1. DynaMed [Internet]. Ipswich (MA): EBSCO Information Services. 1995 – . Record No.T113751, Tardive Dyskinesia; [updated 2018 Nov 30, cited September 9, 2019]. Available from https://www.dynamed.com/topics/dmp~AN~T113751. Registration and login required.
  1. Kim J. (2014). Dextromethorphan for Tardive Dyskinesia. International Neuropsychiatric Disease Journal. 2. 136-140. 10.9734/INDJ/2014/7970.
  2. Tarsy D, Deik A. Tardive dyskinesia: Prevention, prognosis, and treatment. In: UpToDate, Eichler A (Ed), UpToDate, Waltham, MA. (Accessed on September 9, 2019.)
  1. Buttaravoli P, Leffler SM. Chapter 1 – dystonic drug reaction. 2012:1-3. doi:https://doi.org/10.1016/B978-0-323-07909-9.00001-5 “.
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Pediatric Hip PoCUS

Pediatric Hip PoCUS

PoCUS Pearl

Dr. Sultan Ali Alrobaian

Dalhousie EM PoCUS Fellowship

Saint John, NB

@AlrobaianSultan

 

Reviewed and Edited by Dr. David Lewis


 

Case:

A 5 year old healthy boy, came to ED with history of limping since waking that morning. He had worsening right hip discomfort. No history of trauma. He had history of cold symptoms for the last 3 days associated with documented low grade fever.

On physical examination, he looked uncomfortable and unwell looking, he had temperature of 38.1 C, HR 130, BP 110/70, RR 20 and O2 saturation of 98% on RA. He was non-weight-bearing with decreased ROM of right hip because of pain.

Pelvis x-ray was unremarkable, he had WBC of 14.4 x 103  and CRP of 40 .

PoCUS of the right hip was performed.


 

Pediatric Hip Ultrasound

Ultrasonography is an excellent modality to evaluate pathologies in both the intra-articular and extra-articular soft tissues including muscles, tendons, and bursae. PoCUS to detect hip effusion can serve as an adjunct to the history and physical examination in case with hip pain.  It is easily accessible, no radiation exposure and low cost.

Technique:

The child should be in supine position. Expose the hip with drapes for patient comfort. If the patient will tolerate it, position the leg in slight abduction and external rotation. A high frequency linear probe is the preferred transducer to scan the relatively superficial pediatric hip, use the curvilinear probe if increased depth is required.

With the patient lying supine, identify the greater trochanter on the symptomatic hip of the patient. Place the linear probe in the sagittal oblique plane parallel to the long axis of the femoral neck (with the indicator toward the patient’s head).

If the femoral neck cannot easily be found, it can be approached using the proximal femur. Place the probe transversely across the upper thigh. Identify the cortex of the proximal femur and then move the probe proximally until the femoral neck appears medially, then slightly rotate the probe and move medially to align in the long axis of the femoral neck.

Assistance is often required from a parent who may be asked to provide reassurance, apply the gel and help with positioning.

Both symptomatic and asymptomatic hips should be examined.

Negative hip ultrasound in a limping child should prompt examination of the knee and ankle joint (for effusion) and the tibia (for toddler’s fracture)

Hip X-ray should be performed to rule out other causes (depending on age – e.g. Perthes, Osteomyelitis, SCFE, Tumour). Limb X-ray should be performed if history of trauma or NAI.

 

Anatomy of the Pediatric Hip:

The ED Physician should readily identify the sonographic landmarks of the pediatric hip. These landmarks include the femoral head, epiphysis and neck, acetabulum, joint capsule and iliopsoas muscle and tendon.

 

A normal joint may have a small anechoic stripe (normal hypoechoic joint cartilage) between cortex and capsule. This will measure less than 2mm and be symmetrical between hips.

 

Ultrasound Findings:

Measure the maximal distance between the anterior surface of the femoral neck and the posterior surface of the iliopsoas muscle. An effusion will result in a larger anechoic stripe (>2mm) that takes on a lenticular shape as the capsule distends. Asymmetry between hips is confirmatory. Synovial thickening may also be visualized.

FH- Femoral Head, S- Synovium, E – Effusion, FN – Femoral Neck

Criteria for a pediatric hip effusion is:

  • A capsular-synovial thickness of 5 mm measured at the concavity of the femoral neck, from the anterior surface of the femoral neck to the posterior surface of the iliopsoas muscle
  • OR a 2-mm difference compared to the asymptomatic contralateral hip

Right hip effusion, normal left hip, arrow heads – joint capsule, IP – iliopsoas


Interpretation

PoCUS has high sensitivity and specificity for pediatric hip effusion.

  • —
  • Sensitivity of 90%
  • Specificity of 100%
  • Positive predictive value of 100%
  • Negative predictive value of 92%

 

PoCUS cannot determine the cause of an effusion. It cannot differentiate between transient synovitis and septic arthritis. Diagnosis will be determined by combining history, pre-test probability, examination, inflammatory markers and PoCUS findings. If in doubt, septic arthritis is the primary differential diagnosis until proven otherwise.

Several clinical prediction algorithms have been proposed. This post from pedemmorsels.com outlines these nicely:

 

Septic Arthritis

 

 


 

Back to our case:

Ultrasonography cannot definitively distinguish between septic arthritis and transient synovitis, the ED physician’s concern for septic arthritis should be based on history, clinical suspicion and available laboratory findings.

The patient was diagnosed as case of septic arthritis. The patient received intravenous antibiotics empirically. Pediatric orthopedic consultation was obtained, and ED arthrocentesis was deferred as the patient was immediately taken to the operating room for hip joint aspiration and irrigation, confirming the diagnosis.


 

References

 

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Palpitations – A Paroxysmal Pearl

Palpitations – A Paroxysmal Pearl

Medical Student Clinical Pearl

Scott Fenwick

Class of 2021

Faculty of Medicine
Dalhousie University

Reviewed and Edited by Dr. David Lewis


Case Presentation:

A 49-year-old female presented with palpitations for the past 2 hours. She had two similar episodes in the last 2 weeks, both of which resolved within 1-2 minutes. She had no other symptoms. She was otherwise healthy, with no past medical history. She was a non-smoke and non-drinker who leads an active lifestyle. She denied weight loss, diarrhea, and heat intolerance.

On physical exam, she was tachycardic at 130bpm with an irregularly irregular pulse. She did not display any tremor or diaphoresis. On auscultation, S1 and S2 were audible, with no murmurs or extra sounds. Respiratory and abdominal exams were unremarkable.


What to ask on History?

Common Symptoms: palpitations, tachycardia, fatigue, weakness, dizziness, light-headedness, reduced exercise capacity, mild dyspnea, and polyuria. It is essential to know when exactly the symptoms started. AF that presents before 48 hours can be safely rhythm controlled without anticoagulation.(1)

Severe/Secondary Symptoms: angina, dyspnea at rest, presyncope and, uncommonly, syncope. Embolic events and heart failure can be severe complications of AF.

Past Medical History: cardiovascular or cerebrovascular disease, diabetes, hypertension, COPD, obstructive sleep apnea, and hyperthyroidism.


What to look for On Examination?

ABCs and vitals: particularly pulse rate and rhythm.

General Assessment: look for signs of thyroid disease, PE, pulmonary disease, alcohol withdrawal, and signs of liver disease from excessive alcohol ingestion.

CVS: precordial scars from prior cardiac surgery, JVP, peripheral edema, and auscultation for murmurs or additional sounds that might suggest valvular AF. There is often an apical-radial pulse deficit where not every apical beat has an associated radial beat due to lack of left ventricular stroke volume.(2)


Case Continued – Testing:

The patient was put on a cardiac monitor and an ECG was performed, demonstrating atrial fibrillation. There was also a right bundle branch block that was consistent with a previous ECG performed in 2017. Laboratory testing was unremarkable.

Depending on clinical suspicion, initial testing may include CBC, electrolytes, blood glucose, PT/INR, creatinine, BUN, TSH, cardiac enzymes, LFTs, and chest x-ray.2

See Basic ECG interpretation Pearl for a great guide to ECGs

Basic ECG Interpretation


 

Classifying Atrial Fibrillation:

AF is classically described as an irregularly irregular heartbeat, as can be observed from the variable RR intervals in the ECG above. In AF, there are no distinct P-waves due to the uncoordinated atrial activity. Broadly, AF can be divided into valvular and non-valvular subtypes. Non-valvular AF can be classified into the following categories:(1)

  • Paroxysmal – AF terminates spontaneously or with intervention within 7 days of onset.
  • Persistent – AF fails to terminate within 7 days of onset; often a progressive disease.
  • Long-Standing Persistent – AF has persisted for greater than 12 months.
  • Permanent – Joint decision between patient and provider to no longer pursue rhythm control.

AF commonly progresses from paroxysmal to persistent states. The above classification only refers to primary atrial fibrillation, not AF that is secondary to cardiac surgery, pericarditis, myocardial infarction, valvulopathy, hyperthyroidism, pulmonary embolism, pulmonary disease, or other reversible causes.

For persistent and permanent AF, the CHADS2 score can be used to estimate a patient’s 1-year risk of ischemic stroke without anticoagulation (0 = low risk, 1-2 = moderate risk, 3+ = high risk).(1)

Calculate it here

 

CAEP and CCS now recommend using the CHAD-65 Score to determine anticoagulation requirement.

 


 

Treatment

DC and chemical (e.g. procainamide) cardioversion are two well-described methods of treating uncomplicated AF. The goal of treatment is to return patients to NSR. Some important points about the two methods include:

  • DC cardioversion can be administered at an initial energy dose of 100J and increased up to 360J as needed.(2)
  • Procainamide is often given in doses of 15-18mg/kg, or more simply, 1g over 60 minutes. Average time to cardioversion is about 1 hour.(1)
  • DC cardioversion requires procedural sedation; whereas, chemical cardioversion does not.
  • In a recent RCT, combination therapy achieved NSR in 99% of patients; Attempting DC cardioversion first decreased length of hospital stay by 1.2 hours.(3)
  • Both therapies are generally well-tolerated by patients.

Case Continued – Treatment:

The patient was diagnosed with paroxysmal atrial fibrillation. The arrhythmia did not spontaneously resolve in the ED. DC and chemical cardioversion methods were considered and discussed with the patient. Direct Current (DC) cardioversion was performed under procedural sedation with propofol and fentanyl. Shocks of 100J and 200J were unsuccessful in converting the patient into normal sinus rhythm (NSR). A third shock at 300J was ultimately successful. The following ECG was obtained demonstrating NSR. As in the initial ECG, there is a RBBB present.

 

CHADS2 score was 0. Therefore anticoagulation or antithrombotic therapy not indicated.


 

Case Conclusion:

The patient was discharged home within 4 hours of arriving to hospital, anticoagulation was not prescribed. It is likely that she will experience AF again and require anticoagulation later in life.


 

References:

  1. January, C. T., Wann, L. S., Alpert, J. S., Calkins, H., Cigarroa, J. E., Cleveland, J. C., et al. (2014). 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: Executive summary. Journal of the American College of Cardiology, 64(21), 2246. doi:10.1016/j.jacc.2014.03.021
  2. Wakai, A., & Neill, J.O. (2003). Emergency management of atrial fibrillation. Postgrad Med J, 79(932), 313. doi:10.1136/pmj.79.932.313
  3. Scheuermeyer, F. X., Andolfatto, G., Christenson, J., Villa-Roel, C., & Rowe, B. (2019). A multicenter randomized trial to evaluate a chemical-first or electrical-first cardioversion strategy for patients with uncomplicated acute atrial fibrillation. Academic Emergency Medicine, 26(9), 969-981. doi:10.1111/acem.13669
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Color Flow Doppler to Assess Cardiac Valve Competence

Color Flow Doppler to Assess Cardiac Valve Competence

Resident Clinical Pearl (RCP) April 2019

Dr. Scott Foley – CCFP-EM PGY3 Dalhousie University, Halifax NS

Reviewed by Dr. David Lewis

 


 

Background:

When colour Doppler is initiated, the machine uses the principals of the Doppler effect to determine the direction of movement of the tissues off which it is reflecting.

The Doppler effect is the change in frequency of a wave in relation to an observer who is moving relative to a wave source. It was named after the Austrian physicist Christian Doppler who first described the phenomenon in 1842. The classic example is the change in pitch of a siren heard from an ambulance as it moves towards and away from an observer.

These principles are applied to POCUS in the form of colour Doppler where direction of flow is reflected by the colour (Red = moving towards the probe, Blue = moving away from the probe), and the velocity of the flow is reflected by the intensity of the colour (brighter colour = higher velocity).
*Note: the colour does not represent venous versus arterial flow.

 

The use of colour Doppler ultrasound can be useful in the emergency department to determine vascular flow in peripheral vessels as well as through the heart. It is one way to determine cardiac valve competency by focusing on flow through each valve.


 

Obtaining Views:

To optimize valve assessment, proper views of each valve must be obtained. It is best to have the direction of the ultrasound waves be parallel to the direction of flow. External landmarks for the views used are seen below:

  • Mitral Valve and Tricuspid Valve: The best view for each of these is the apical 4 chamber view. If unable to obtain this view, the mitral valve can be seen in parasternal long axis as well.
  • Aortic Valve: The best view is the apical 5 chamber or apical 3 chamber but are challenging to obtain. Instead, the parasternal long axis is frequently used.
  • Pulmonic Valve: Although not commonly assessed, the parasternal short axis can be used.
  • Visit 5minutesono.com for video instruction on obtaining views

Parasternal long axis: MV, AV

Parasternal short axis: PV, TV

Apical 4 chamber: TV, MV


 

Assessing Valvular Competency:

How to examine valvular competency:

  1. Get view and locate valve in question
  2. Visually examine valve: opening, closing, calcification
  3. Use colour Doppler:
    1. Place colour box over valve (as targeted as possible (resize select box) to not include other valves)
    2. Freeze image and scroll through images frame by frame
    3. Examine for pathologic colour jets in systole and diastole
  4. Estimating severity:
    1. Grade 1 – jet noticeable just at valve
    2. Grade 2 – jet extending out 1/3 of atrium/ventricle
    3. Grade 3 – jet extending out 2/3 of atrium/ventricle
    4. Grade 4 – jet filling entire atrium/ventricle

See video tutorial below for more


Mitral Regurgitation A4C

Tricuspid Regurgitation A4C

Aortic Stenosis PSLA


Bottom line:

Color flow Doppler on POCUS is a straightforward way to assess for valvular competency in the Emergency Department. A more detailed valvular assessment requires skill, knowledge and experience.

 


Useful Video Tutorials:

Mitral Regurgitation

 

Aortic Stenosis vs Sclerosis

Tricuspid Valve


References:

  1. https://www.radiologycafe.com/medical-students/radiology-basics/ultrasound-overview
  2. By Patrick J. Lynch and C. Carl Jaffe – http://www.yale.edu/imaging/echo_atlas/views/index.html, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=21448310
  3. 5minutesono.com
  4. ECCU ShoC 2018 powerpoint, Paul Atkinson, David Lewis
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Approach to Resuscitation in Severe Calcium Channel Blocker Poisoning

Medical Student Clinical Pearl

J.L. Dobson

Faculty of Medicine
Memorial University of Newfoundland
M.D. Candidate 2020

Reviewed and Edited by Dr. Luke Taylor and Dr. David Lewis

and Liam Walsh. Pharmacist HHN


 

Introduction:

Calcium channel blockers (CCBs) have multiple clinical uses, including the management of hypertension, angina, and cardiac arrhythmias. [1] While CCBs are no longer the most widely prescribed antihypertensive as they were in the 1990s, their prevalence remains high. [2] This along with the existence of both immediate release and long-acting forms poses a challenge for the Emergency Physician faced with a case of CCB poisoning.

Physiology:

Myocardium in the sinoatrial and atrioventricular nodes uses the slow action potential created by calcium currents to conduct. CCBs act on this tissue by inhibiting this current, thus slowing conduction through the SA and AV nodes. This results in a decreased heart rate, prolonged PR intervals, and lengthened refractory periods through the AV node. Conversely, they also inhibit calcium flow in smooth muscle, resulting in coronary and peripheral artery dilation. This ultimately provides the mechanism for reflex tachycardia, increased AV conduction, and improved myocardial contractility. [3]

Adverse reactions to the physiological effects of CCBs include vasodilatory effects (peripheral edema, headache, palpitations), gastrointestinal effects (nausea, diarrhea, constipation), and negative inotropic effects (hypotension, bradycardia). [4]


 

Case Report:

A 80-year-old male is brought in to Trauma by ambulance with hypotension, bradycardia, and an altered level of consciousness. Report from EMS reveals the patient called about half an hour prior stating that he had taken medications in an attempt to commit suicide. Upon arrival, the pt was alert and oriented, and endorsed taking an unknown quantity of clonazepam and citalopram, and a deficit of up to four grams of Diltiazem was noted from his medications. He denied further substance use. Though initially stable, the patient deteriorated rapidly upon arrival to the emergency department.

In the Emergency Department, initial vitals revealed a BP of 88/68, P of 52 bpm and SPO2 of 93% on RA and a BG of 15. As such nasal prongs were placed and she was immediately given atropine as well as push dose epinephrine. Within ten minutes, there was further decline in mental status of the patient corresponding to a blood pressure of 83/61 and a heart rate persisting in the low 40s bpm. He was successively given further epinephrine, atropine and calcium chloride while toxicology was contacted. Despite recurrent doses of epinephrine and atropine, the patient remained profoundly hypotensive and bradycardic. Insulin (Humulin R) and dextrose were started at 0.5U/kg/hr with a 1U/kg bolus. This infusion was titrated up every thirty minutes with minimal improvement in vitals. At this point, remaining bradycardic at 37bpm, intralipid therapy was deemed necessary and so a bolus of 105mL was given. Having received epinephrine bolus along with a 0.2mcg/kg/hr infusion, maximum dose of atropine, 3g of Calcium chloride, with minimal clinical improvement cardiac pacing was initiated. Once good electrical and mechanical capture were achieved the patient underwent and RSI with ketamine and rocuronium. Once stabilized, he was transferred to ICU for further management. In ICU, the patient had a transvenous pacemaker floated successfully followed by a transitioning off the epinephrine to norepinephrine and vasopressin. Intralipid infusion was started and the insulin and glucose therapy was titrated up to a maximum of 4U/kg/hr. The patient unfortunately did not tolerate whole bowel irrigation. Despite the critical nature of their condition, the patient did slowly improve and pressors were weaned.


 

Discussion:

History & Primary Survey

This patient experienced negative inotropic effects of the extended release calcium channel blocker, resulting in cardiogenic shock. Ingestion of more than 5-10 times the usual dose of CCB results in severe intoxication: this patient was thought to have consumed four grams of Diltiazem, over eleven times the maximum recommended dose. [5] While any CCB can result in hypotension, knowledge of which CCB was taken is useful to set expectations for the patient’s progression: unlike dihydropyridine-type CCBs which would more likely present with reflex tachycardia, non-dihydropyridine CCBs like verapamil and diltiazem result in bradycardia. [6] Another crucial point in the primary survey is that, due to the neuroprotective effects of CCBs, mental status may initially be preserved until cerebral perfusion is severely affected. [5]

Initial Resuscitation

While the patient may initially be able to maintain their airway, mental status and vitals may deteriorate rapidly. [5] It is important to note that like any critical ill patient,  intubation may result in a further drop in heart rate and blood pressure via vagal stimulation. It is crucial to have adequate resuscitation prior to intubation. IV crystalloid fluids , IV atropine (up to three 1mg doses), as well as push dose epinephrine are interventions that can be used quickly at bedside to maintain circulation and heart rate while further investigations and treatments can be organized. [5,8]


Specific Treatments

For a severe CCB poisoning in which hypotension is refractory to IV fluids and atropine, all of the following treatments should be administered simultaneously. If the severity is milder, these treatments should be approached in a stepwise fashion, progressing to the next if the preceding treatment is ineffective. [5]

IV Calcium salt:

As a first line recommendation, a calcium chloride bolus (10-20mL 10%) followed by a continuous infusion (0.5 mEq Ca2+/kg/hr) or the equivalent of calcium gluconate is recommended, though often ineffective. [5] Mortality has been shown to be reduced with its administration, and hypercalcemia occurs only rarely. [7] [8]

IV Insulin with dextrose:

High-dose insulin therapy (1 u/kg bolus and 0.5 u/kg/hr infusion up to 10 u/kg/hr) has been shown to be safe and effective at improving hemodynamics, though response is delayed for 30-60 minutes. [5,7] It should be used with calcium and a vasopressor in the presence of myocardial dysfunction. [8] Blood glucose levels should be monitored every 15-30 minutes for hypoglycemia, and 50mL boluses of dextrose (D50W) given accordingly to maintain levels above 8.25 mM. [5] Hypokalemia is another risk of insulin therapy, therefore electrolytes should be monitored every 30 minutes and 20 mEq of potassium chloride given if needed. [5,7]

IV Vasopressor:

Administration of IV epinephrine has shown improvement in cardiac output. [7,8] In the setting of severe CCB poisoning, doses as high as 150mcg per minute of epinephrine may be needed. It is suggested to start the infusion at 2mcg per minute and titrate up to a systolic blood pressure of 100 mmHg, or a MAP of 65 mmHg. [5] These higher doses may result in a large improvement in patient MAP with minimal change in heart rate.

IV Lipid emulsion therapy:

If the patient is refractory to first-line treatments above, or upon consultation with medical toxicology centre, IV lipid emulsion therapy may be recommended. [8] Most commonly, this is given as a bolus of 1.5 mL/kg of 20% lipid emulsion, repeated up to every three minutes for three total boluses. An infusion of 0.25-0.5 mL/kg/minute may be started. [5] Complications of this treatment are still being studied.

Other considerations:

Studies most often show improvement of hemodynamics and no adverse effects with temporary cardiac pacing for bradycardia refractory to first-line treatments. [7,8] Extracorporeal membrane oxygenation may also be necessary if the patient is near cardiac arrest and remains refractory to previous treatments. [8] Dialysis provides no benefit. [5]

Decontamination:

If the patient is asymptomatic and/or hemodynamically stable, 50g of activated charcoal should be given. In the case of ingestion of extended-release CCBs, whole bowel irrigation should be performed regardless of the presence of symptoms. An asymptomatic patient should be monitored for 6-8 hours for immediate release and 24 hours for extended release forms. [5,8]

Investigations:

ECG may reveal PR interval prolongation due to CCB actions on the SA and AV nodes. Frequent blood glucose measurements are crucial to monitor for the effects of insulin treatment and the need for glucose replacement. Serum electrolytes, notably potassium levels, must be assessed for developed hypokalemia secondary to insulin treatment.



Conclusion:

We present a case and review the physiology of a severe calcium channel blocker poisoning. Key considerations in managing a CCB poisoning include specific dosage and form, initial resuscitation with a low threshold for intubation, fluids, and atropine. Further treatments will be required based on severity, such as intravenous calcium, insulin with dextrose, and lipid emulsion therapy, all of which should be initiated promptly if there is concern for massive over dose and patient declining. Other considerations include the need for further vasopressors and temporary cardiac pacing.

 


FIGURE: Society of Critical Care Medicine key recommendations for management of CCB poisoning. Source: “Experts consensus recommendations for the management of calcium channel blocker poisoning in adults.” Crit Care Med. 2017;45(3):e306-e315. DOI: 10.1097/CCM.0000000000002087


 

References:

[1] Elliott, WJ & Ram,CV. J Clin Hypertens (Greenwich). 2011;13:687–689.

[2] Eisenberg, MJ; Brox, A. & Bestawros, AN. Am J Med. 2004;116(1):35-42.

[3] Singh, BN; Hecht, HS; Nademanee, K. & Chew, CYC. Progress in Cardiovascular Diseases. 1982;15(2):103-132.

[4] Russell, RP. Hypertension. 1988;11(3):II42-44.

[5] Barrueto, F. “Calcium channel blocker poisoning.” UpToDate. 2019.

[6] Hofer, CA; Smith, JL & Tenholder, MF. Am J Med. 1993;95(4):431.

[7] St-Onge, M; Dubé, PA; Gosselin, S; Guimont, C; Godwin, J; Archambault, PM; Chauny, JM; Frenette, AJ; Darveau, M; Le Sage, N; Poitras, J; Provencher, J; Juurlink, DN & Blais, R. Clin Toxicol (Phila). 2014;52(9):926.

[8] St-Onge, M; Anseeuw, K; Cantrell, FL; Gilchrist, IC; Hantson, P; Bailey, B; Lavergne, V; Gosselin, S; Kerns, W; Laliberté, M; Lavonas, EJ; Juurlink, DN; Muscedere, J; Yang, CC; Sinuff, T; Rieder, M & Mégarbane, B. “Experts consensus recommendations for the management of calcium channel blocker poisoning in adults.” Crit Care Med. 2017;45(3):e306-e315.

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Shining a light on acute vision loss: PoCUS for the retina

Shining a light on acute vision loss: PoCUS for retinal pathology

Resident Clinical Pearl (RCP) August 2019

Dr. Devon Webster – PGY2 FMEM Dalhousie University, Saint John NB

Reviewed by Dr. Kavish Chandra

 

It’s a quiet night in RAZ and you pick up your next chart- a 68 year old Ms. Iris Snellen has come in with new onset, painless, monocular vision loss. You pick up the ophthalmoscope to perform fundoscopy, and despite your best attempts, like many ED physicians before you, you see nothing helpful. So instead you pick up your investigative tool of choice, the ultrasound probe, and begin your ocular POCUS exam…


Anatomy and pathophysiology

The retina is composed of multiple layers of neurons that allow for the human eye to convert light energy (photons) into images within the occipital brain. The retina sits on top of the vascular choroid which provides blood flow.

Fundoscopy allows for visualization of the following structures:

  • Optic disc
  • The macula (central, high-resolution, color vision)
  • The fovea (sits centrally in the macula and provides sharp, central vision)
  • The retinal artery and vein

https://stanfordmedicine25.stanford.edu/the25/fundoscopic.html

 

PoCUS is adjunctive test to assess for vision-threatening and common conditions impacting the eye such as retinal detachment (RD), posterior vitreous detachment (VD) and vitreous hemorrhage (VH).

A normal eye should allow you to visualize the following structures:

https://www.nuemblog.com/ocular

In retinal detachment, the retina is separated from the choroid either through formation of a hole in the retina, peeling away from the choroid if attached to the vitreous humour or through edematous infiltration between the two layers. Separation results in rapid ischemia and death of photoreceptors with subsequent vision-loss.

Posterior vitreous detachment is common and occurs secondary liquification of the gel-like vitreous body.

Vitreous hemorrhage can occur secondary trauma, spontaneous retinal tears or vitreous detachment or any cause of retinal neovasculiarzation such as in diabetes.

 


Retinal detachment and the DDx

When assessing your pt, a retinal detachment should be at the top of your list of diagnoses to rule out given that prompt recognition and referral to ophthalmology may be a vision-saving intervention.

On history she may describe the following features of RD:

  • Floaters: may appear as spiderwebs, a large spot that comes and goes that may ‘look like a big fly’ or a showering of many small black dots.
  • Painless monocular vision loss: may present as a ‘curtain descending’ across her vision and/or visual field loss.
  • Flashes: may be easier to see at night or in a dark room (consider turning off the lights in the exam room)

Assess for risk factors for retinal detachment:

  • Myopia (near-sightedness): Major risk factor!
  • Cataract surgery
  • Family history of retinal detachment
  • Diabetes
  • Glaucoma
  • Old age
  • History of posterior vitreous detachment

Physical exam:

  • Assess for changes in visual acuity
  • Assess for loss of visual fields
  • Fundoscopy may reveal advanced detachments however, early detachments are often not visible with direct fundoscopy. Advanced detachments may reveal absence of a red reflex and a billowing retinal flap.
  • Ultrasound!

Your DDx may include:

  • Posterior vitreous detachment
  • Vitreous hemorrhage
  • Ocular migraine
  • CRAO/CRVO
  • Amaurosis fugax

(see below for distinguishing features of the DDx)

 


The PoCUS assessment

Most ED physicians feel more comfortable with their ultrasonography skills over their fundoscopy skills. PoCUS is a fast, portable and radiation-free approach to assessing patients for potential vision-threatening pathology such as retinal detachment. While ultrasonography should not replace ophthalmologic assessment and fundoscopy, it can be used as an additional tool to support your primary diagnosis.

Most recently, Lanham, et al., published a prospective diagnostic study involving 225 patients and 75 ED providers that found POCUS was 96.9% sensitive and 88.1% specific for the diagnosis of retinal detachment1. While studies have varied in whether sensitivity was better than specificity or vice versa, ultimately each study has shown that when trained, emergency providers are quite good at identifying RD by US2,3. In addition to RD, Lanham, et al further found ED providers did well at identifying vitreous hemorrhage (sens 81.9%, sp 82.3%) and vitreous detachment (sens 42.5%, sp 96%).

Get the PoCUS Scan:

  • Place a tegaderm over the eye to protect it from US gel which may be painful. You may consider using topical freezing drops to limit irritation.
  • Use the linear probe and scan through the eye until you are able to visualize the optic nerve, the hypoechoic structure at the back of the eye
  • Have the patient look side to side/up and down as this will accentuate movement of retinal or vitreous pathology.
    1. Retinal detachment: Bright echogenic line that appears to have separated from the posterior eye/choroid and remains tethered to the optic nerve.
    2. Posterior vitreous detachment: Bright echogenic line separated from posterior eye/choroid that is detached from the optic nerve.
    3. Posterior vitreous hemorrhage: Vitreous shows fluid collection with variable echogenicity and ‘washing machine’ appearance.

Jacobsen et al. (2016). WestJEM. 17(2)

 

Differential of painless visual loss

 

Resources:

  1. Lahham S, et al. Point-of-Care Ultrasonography in the Diagnosis of Retinal Detachment, Vitreous Hemorrhage, and Vitreous Detachment in the Emergency Department. JAMA Netw Open. Published online April 12, 20192(4):e192162. doi:10.1001/jamanetworkopen.2019.2162
  2. Kim, D., et al. Test Characteristics of Point-of-care Ultrasound for the Diagnosis of Retinal Detachment in the Emergency Department. Academic Emergency Medicine. 2019;26[1]:16; http://bit.ly/2TEFutH
  3. Vrablik ME, et al. The diagnostic accuracy of bedside ocular ultrasonography for the diagnosis of retinal detachment: a systematic review and meta‐analysis. Ann Emerg Med 2015; 65( 199–203): e1.
  4. Mason, J. (Host). (2019 Jan). C3-Vision Loss-Retinal Detachment [Audio podast]. Retrieved from EMRAP: https://www.emrap.org/episode/c3visionloss/c3visionloss1 .
  5. Arroyo, J. (Jan 2018). Retinal Detachment. Retrieved from Uptodate: https://www.uptodate.com/contents/retinal-detachment
  6. Givre, S., et al. (Feb 2019). Amaurosis fugax (transient monocular or binocular visual loss). Retrieved from Uptodate: https://www.uptodate.com/contents/amaurosis-fugax-transient-monocular-or-binocular-visual-loss?search=painless%20monocular%20vision%20loss&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
  7. Porfiris, G. (2015). ABCs of Emergency Medicine, 14th Edition, Chapter 23: Eye Emergencies.

 

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Ultrasound guided hematoma block for distal radius fractures

Ultrasound guided hematoma block for distal radius fractures

Resident Clinical Pearl (RCP) September 2019

Robert Dunfield – PGY1 FMEM Dalhousie University, Saint John NB

Reviewed by Dr. Kavish Chandra

 

Mr. JG, a 34 year old male snowboarder, presents to your busy emergency department after a snowboarding accident. He suffered a fall onto his left outstretched hand after hitting a jump that was approximately one foot high. Radiograph shows a closed distal radius fracture with significant  dorsal angulation.

Figure courtesy of Dr Pir Abdul Ahad Aziz, Radiopaedia.org, rID: 47908

Tonight is a busy shift and you’re working in a resource-limited department with very few staff. In speaking with the patient, he’s nervous about the prospect of procedural sedation and would prefer to not be “put to sleep to fix [his] wrist”. Luckily, your department recently purchased an ultrasound machine and the patient consents to a hematoma block prior to reduction.


What is a hematoma?

Following the initial impact that causes a fracture, the initial stage of bone healing involves a hematoma formation. In simple terms, a hematoma is a large blood clot that collects at the fracture site. Hematomas are rich in vascular supply and are the site of eventual soft callus formation; they’re the result of bony blood supply being disrupted at the site of the defect

 

Stages in Fracture Repair. The healing of a bone fracture follows a series of progressive steps: (a) A fracture hematoma forms. (b) Internal and external calli form. (c) Cartilage of the calli is replaced by trabecular bone. (d) Remodeling occurs.1

 

Hematoma blocks as an alternative to procedural sedation?

Compared to procedural sedation, hematoma blocks can be done safely when procedural sedation is not an option or is contraindicated. They also offer an alternative option for analgesia when an emergency department is busy and resources are lacking to safely perform procedural sedation.2

  • Procedural sedation requires a period of recovery after the procedure, hematoma blocks do not necessitate traditional post procedural recovery.3
  • Evidence that suggests post-procedure analgesia is similar in hematoma block patients compared to patients who undergo procedural sedation.4
  • Hematoma blocks are a form of local anaesthesia that can be used when reducing simple, closed distal long bone fractures, like the distal radius fracture in this case. They can also be performed to provide analgesia for nondisplaced fractures.2

 

Prior to the advent of bedside ultrasound, hematoma blocks were dependent on external anatomy landmarking, using “step-off” site of the bony deformity as the landmark for injection. This can be difficult, however, in fractures where swelling, habitus, or deformity can distort the anatomy of the hematoma.2 This is where ultrasound plays a role in identifying the deformity and therefore improves the precision of hematoma injection.

Contraindications to hematoma block include allergy to the anaesthetic being used, if the fracture is open, if there is cellulitis overlying the site of the fracture, and/or if there is a neurovascular deficit on exam of the affected limb.5

 

Performing  a hematoma block under US guidance

Mr. JG requires reduction of his distal radius fracture. Due to his uneasiness with procedural sedation, combined with the busy and resource-strained nature of your emergency department, a hematoma block under ultrasound guidance is performed.

 

  • Gain informed consent: The initial step in performing a hematoma block is similar to all medical procedures in that the patient undergoing the procedure should be informed of the risks associated with hematoma blocks and fracture reduction. These include, although rare, compartment syndrome, local anesthetic toxicity, acute carpal tunnel syndrome, and temporary paralysis of the upper limb6. Remember that maximum dose of lidocaine without epinephrine is 5mg/kg.
  • Reassess the neurovascular integrity of the limb: Prior to injecting the hematoma block, ensure you have confirmed neurovascular integrity of that limb.
  • Grab the supplies you’ll need: The following list is limited to the supplies needed for your hematoma block and does not include the supplies needed for fracture reduction and casting.
    • Ultrasound machine with a linear transducer probe
    • Tegaderm transparent film
    • Sterile lubricating jelly
    • Sterile skin marker
    • Sterile gloves
    • Chlorhexidine swabs x 3
    • 16G Needle (for drawing up analgesia)
    • 20G or 22G Needle (for injecting analgesia)
    • 10mL syringe
    • 1% lidocaine (approximately 10mL)
  • Landmark the hematoma using point of care ultrasound: Trace the bone’s cortex on the dorsal aspect of the forearm from the proximal aspect of the fracture towards the fracture site until you reach an interruption in the cortex of the radius (see below). Mark that site with your marker for injection.

Left: Sagittal image of left radius outlining an interruption in the radial cortex at the site of the hematoma. Right: Same image, edited to identify anatomy.8 Edited by Robert Dunfield PGY1-Dalhousie

  • Clean the site and prepare other materials: Clean the site with chlorhexidine swabs x 3. Allow it to dry while you prepare the remainder of your equipment. Draw up your 10mL of 1% lidocaine with the 16G needle and then change the needle to your 20 or 22G needle. A longer needle may be needed to reach the site of the hematoma.
  • Prepare your transducer: Clean your linear transducer and then put on your sterile gloves. With the help of an assistant apply the sterile tegaderm film to the liner transducer and place sterile lubricating jelly on the probe.
  • Insert needle under US guidance: Using the probe to visualize the site of the hematoma, simultaneously begin to insert the needle in a caudal fashion toward the hematoma, visualizing the needle in the long axis. Use the ultrasound image to follow the needle’s insertion.

Injection of hematoma block under ultrasound guidance.6 Modified by Robert Dunfield PGY1-Dalhousie

  • Inject the lidocaine: Inject 10mL of 1% lidocaine into the hematoma.
  • Give time for analgesia to take effect: Allow 5 to 10 minutes of time to allow the analgesia to take full effect, then reassess neurovascular integrity.
  • Proceed with the reduction.
  • Added note: It’s possible for distal radius fractures to have an associated ulnar styloid fracture, which will require repeating the same steps as described above, only at the side of the ulnar fracture.

 

Summary:

    • Hematoma blocks under ultrasound guidance can be done on certain distal long bone fractures that lack any contraindications
    • Use the ultrasound probe to trace the bone’s cortex and identify the site of the hematoma, then insert the needle into the hematoma under the guidance of your linear transducer.
    • Confirm needle placement into the hematoma by aspiration and inject 10mL of 1% lidocaine into the hematoma.
    • Allow 5 to 10 minutes of analgesia onset before reducing the fracture.
    • Remember to reassess the limb’s neurovascular integrity before and after the procedure.

Copyedited by Kavish Chandra

 

Resources:

  1. Rice University. Anatomy and Physiology. Chapter 6.5: Bone Repair. https://opentextbc.ca/anatomyandphysiology/chapter/6-5-fractures-bone-repair. Accessed: September 03, 2019. Last updated: unknown.
  2. Gottlieb M and Cosby K. Ultrasound-guided hematoma block for distal radial and ulnar fractures. Journal of Emergency Medicine. 2015;48(3):310-312.
  3. Alerhand S and Koyfman A. Ultrasound-Guided Hematoma Block. emDocs.net. http://www.emdocs.net/ultrasound-guided-hematoma-block/. Accessed: September 07, 2019. Last updated: December 21, 2014.
  4. Fathi M, Moezzi M, Abbasi S, Farsi D, Zare MA, Hafezimoghadam P. Ultrasound-guided hematoma block in distal radial fracture reduction: a randomised clinical trial. Emerg Med J. 2015;32:474-477.
  5. Reichman EF. Emergency Medicine Procedures. Second Edition. 2013:Chapter 125 Hematoma Blocks.
  6. Emiley P, Schreier S, Pryor P. Hematoma Blocks for Reduction of Distal Radius Fractures. Emergency Physicians Monthly. https://epmonthly.com/article/hematoma-blocks-for-reduction-of-distal-radius-fractures/. Accessed: September 14, 2019. Last updated: February 2017.
  7. Beaty JH and Kasser JR. Rockwood and Wilkins’ Fractures in Children. Chapter 3: Pain Relief and Related Concerns in Children’s Fractures, pp61-63.
  8. EM Cases and POCUS Toronto. POCUS Cases 4: Distal Radius Fracture. https://emergencymedicinecases.com/video/pocus-cases-4-distal-radius-fracture/. Accessed: September 14, 2019. Last updated: July 2018.
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EM Reflections – September 2019

Thanks to Dr Paul Page for leading the discussions this month

Edited by Dr David Lewis 

 


Discussion Topics

  1. Refractory Hypotension / Sepsis – ‘ringing the changes

  2. Hypertensive Urgency / Emergency – “I was sent to the ER by the pharmacy checkout assistant

  3. Investigation Reports / Systems / Adverse Events


Refractory Hypotension / Sepsis

 

This interesting historical perspective from NPR makes an interesting read on the origins of Normal Saline

As it turns out, normal saline isn’t very normal at all. The average sodium level in a healthy patient is about 140 (as measured in something called milliequivalents per liter). For chloride, it’s about 100. But the concentration of both sodium and chloride in normal saline is 154. That’s pretty abnormal—especially the chloride.

Sidney Ringer (click for biography)

 

 “Among critically ill adults, the use of balanced crystalloids for intravenous fluid administration resulted in a lower rate of the composite outcome of death from any cause, new renal-replacement therapy, or persistent renal dysfunction than the use of saline.” Semler MW, Self WH, Wanderer JP, et al. Balanced crystalloids versus saline in critically ill adultsN Engl J Med. 2018;378:829-839.

Data Suggests Lactated Ringer’s Is Better than Normal Saline – ACEP Now

PulmCrit- Get SMART: Nine reasons to quit using normal saline for resuscitation

Take Home

  • Re-consider cause of hypotension in patients not responding to IV fluid resuscitation.
  • High mortality for elderly patients presenting to ED with hypotension.
  • Early switch to Ringers Lactate for IV fluids if needed for large volume resuscitation in sepsis.
  • If a British doc asks for Hartman’s, use Ringer’s… it’s the same.

 


 

Hypertensive Urgency / Emergency

Although elevated blood pressures can be alarming to the patient, hypertensive urgency usually develops over days to weeks. In this setting, it is not necessary to lower blood pressure acutely. A rapid decrease in blood pressure can actually cause symptomatic hypotension, resulting in hypoperfusion to the brain

RxFiles.ca summary pdf

How should I manage patients who present with a hypertensive urgency — i.e. BP > 180/120 mm Hg without impending or progressive end-organ damage (e.g. patient with headache, shortness or breath or epistaxis)?

  • For patients with hypertensive urgencies
    • Optimize (or restart) their current treatment regimens
    • Consider oral short-acting agents (e.g. captopril, labetalol, clonidine)
    • Do not treat aggressively with intravenous drugs or oral loading
    • Ensure that the patient has a follow-up appointment within a few days

How should I manage patients who present with a hypertensive emergency — i.e. BP > 180/120 mm Hg and impending or progressive end-organ damage (e.g. neurologic, cardiovascular, eclampsia)?

  • Reduce BP immediately with intravenous drugs, and monitor BP continuously in an intensive care setting.
  • Consider using the following drugs:
    • Vasodilators: sodium nitroprusside, nicardipine, fenoldopam mesylate, nitroglycerin, enalaprilat, hydralazine
    • Adrenergic blockers: labetalol, esmolol, phentolamine
  • Do not use short-acting nifedipine (lowers BP fast enough to provoke ischemia).
  • Aim for 25% reduction of the mean arterial blood pressure within minutes to 1 hour o Then if the patient is stable, reduce BP to 160/100-110 mm Hg over 2-6 hours and normalize within 24-48 hours.
  • Exceptions include stroke (unless BP is lowered to allow thrombolytic agents to be used) and dissecting aortic aneurysm (target systolic BP is < 100 mm Hg if possible).

from GAC Guidelines

Episode 40: Asymptomatic Hypertension

 

Take Home

  • Most patients with elevated BP (greater than 180/110) that are asymptomatic can safely follow up with Family Doctor.
  • True hypertensive emergencies are infrequent.
  • If mild symptoms consider starting antihypertensives in ED if unsure about follow up.
  • No good evidence that starting in antihypertensives ED for patients that can access their Family Doctor within next few days improves outcomes.

 


 

Radiology Reports / Systems / Adverse Events

 

Failure to follow up on radiology studies has become a frequent claim against both EPs and radiologists, according to Darien Cohen, MD, JD, an attending physician at Presence Resurrection Medical Center and clinical assistant professor in the Department of Emergency Medicine at University of Illinois, both in Chicago.

  • ED policies should ensure that all radiology alerts are available in a single location, and it must be clear who is responsible for follow-up.
  • Follow-up must be clearly documented in the medical record.
  • Any incidental finding mentioned on the radiology report should be communicated to the patient, and this communication must be clearly documented in the medical record.

 

Adverse Events Related to Emergency Department Care: A Systematic Review

A greater proportion of AE were preventable among the discharged population (71.4%; n = 15) than among the admitted population (40.9%; n = 9). Among discharged patients, management issues (47.6%; n = 10), diagnostic issues (33.3%; n = 7), and unsafe dispositions decisions (19%; n = 4) were the most common causes of AE

 

Safeguards in the system of care are like slices of cheese with holes representing possible failure points. See the Swiss Cheese Model at CMPA.ca

 

WTBS 9 – EM Quality Assurance Part One: Improving Follow up from the ED

 

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Lung Ultrasound in the Evaluation of Pleural Infection

Lung Ultrasound in the Evaluation of Pleural Infection

Resident Clinical Pearl (RCP) July 2019

Yazan Ghanem PGY5 Internal Medicine, Dalhousie University

SJRHEM PoCUS Elective

 

Reviewed and edited by  Dr. David Lewis.

 


CASE: MR. WHITE

 

83 year old male with known past medical history of mild cognitive impairment (lives alone in assisted living). Two weeks prior to current presentation, he was admitted with community acquired pneumonia and discharged after 2 nights of hospital stay on oral antibiotics.

He is now presenting with 5 days history of worsening dyspnea, fever, fatigue and reduced oral intake. Vital signs are: Temperature 38.4 C; heart rate 80/min; Blood pressure 121/67; Respiratory rate 28/ minute; Oxygen saturation 90% on room air. His chest exam showed reduced air entry and dullness to percussion in the right hemithorax.

CXR:

 

Bedside POCUS:

 

Pleural fluid analysis:

•       WBC – 22,000 cells per uL

•       LDH – 1256 Units / L

•       Glc – 2.2 mmol / L

•       pH – 7.18

•       Gram Stain – Neg

 

Next steps in management?

 

A – 14 Fr pleural drain + Start IV Levofloxacin

 

B – 28 Fr pleural drain + Start Ceftriaxone / Azithromycin

 

C – 14 Fr pleural drain + Start Piperacillin – Tazobactam

 

D – Start Ceftriaxone / Azithromycin + Repeat CXR in 1 week

 

 

(See end of page for answer )

 


 

Normal Thoracic Ultrasound:

Thoracic Ultrasound is limited by bony structures (ribs and scapulae) as well as by air within lungs (poor conductor of sound waves).

With the transducer held in the longitudinal plane:

1 –     Ribs are visualized as repeating curvilinear structures with a posterior acoustic shadow.

2 –     Overlying muscle and fascia are seen as linear shadows with soft tissue with soft tissue echogenicity.

3 –     Parietal and visceral pleura is visualized as a single echogenic line no more than 2 mm in width which “slides” or “glides” beneath the ribs with respiration. Two separate lines can be seen with a high frequency transducer.

4 –     Normal aerated lung blocks progression of sound waves and is characterized by haphazard snowstorm appearance caused by reverberation artifact.

5 –     Diaphragms are bright curvilinear structures which move with respiration. Liver and spleen have a characteristic appearance below the right and left hemi diaphragms respectively.

 

 


Pleural Effusion:

Ultrasound has higher sensitivity in detecting pleural effusions than clinical examination and chest X-Ray.

On Ultrasound, pleural effusions appear as an anechoic or hypoechoic area between the visceral and parietal pleura that changes in shape with respiration. Atelectatic lung tissue appear in the far field as flapping or swaying “tongue-like” echodensities.

Ultrasound morphology:

1-     Anechoic Effusion: Totally echo-free (Could be transudative or exudative)

2-     Complex Non-septated: Echogenic appearing densities present (fibrinous debris). Always exudative.

3-     Complex Septated: Septa appear in fluid. Always exudative.

 

 


Parapneumonic Effusions and Empyema:

Ultrasound is superior to CT in demonstrating septae in the pleural space. However, CT is recommended for evaluation of complex pleuro-parenchymal disease and loculated pleural collections if drainage is planned: There is no correlation between ultrasound appearance and the presence of pus or need for surgical drainage; however, the presence of a septated appearing parapneumonic effusion correlate with poorer outcomes (longer hospital stay, longer chest tube drainage, higher likelihood for need for fibrinolytic therapy and surgical intervention.

Parapneumonic effusions appear as hyperechoic (with or without septae) on ultrasound.

 


Pulmonary Consolidation:

Pulmonary consolidation is sonographically visible in the presence of a pleural effusion that acts as an acoustic window or if directly abutting the pleura.

It appears as a wedge-shaped irregular echogenic area with air or fluid bronchograms.

 


 

Back to Mr. White

 

Next steps in management?

 

A – 14 Fr pleural drain + Start IV Levofloxacin

 

B – 28 Fr pleural drain + Start Ceftriaxone / Azithromycin

 

C –14 Fr pleural drain + Start Pipercillin- Tazobactam

 

D – Start Ceftriaxone / Azithromycin + Repeat CXR in 1 week

 

Rationale:

Complicated parapneumonic effusions should be managed with drainage and antibiotics that will treat anaerobic infection. An alternative would be a combination of Ceftriaxone and Metronidazole (No pseudomonas coverage). Levofloxacin alone does not add any anaerobic coverage. Azithromycin has poor penetration into loculated pleural collections.

 


 References

 

British Thoracic Society – Pleural Disease Guideline – 2010

https://thorax.bmj.com/content/65/8/667

 

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ADULT Rapid Sequence Intubation and Post-Intubation Analgesia and Sedation for Major Trauma Patients – NB Trauma

Consensus Statement:

ADULT Rapid Sequence Intubation and Post-Intubation

Analgesia and Sedation for Major Trauma Patients

NB Trauma Program – July 2018

Background:

  • Major trauma patients frequently require advanced airway control.
  • Endotracheal intubation is the preferred advanced airway intervention in major trauma patients.
  • Intubated trauma patients also need significant post-intubation pharmacological support.
  • Specifically, these patients require analgesia and sedation. This is particularly true when transfer to another facility is required, during which ICU level support is not available unless transfer occurs via Air Ambulance.
  • In New Brunswick, there is significant variation in the approach to both advanced airway control and post-intubation analgesia and sedation practices for major trauma patients.
  • Physicians in smaller centres in particular have asked for standardized, evidence-based guidance for both Rapid Sequence Intubation (RSI) and post-intubation pharmacological support in preparation for (and during) ground-based interfacility transfer.
  • Rapid Sequence Intubation (RSI) is a method to achieve airway control that involves rapid administration of sedative and paralytic agents, followed by endotracheal intubation.
  • The purpose of RSI is to affect a state of unconsciousness and neuromuscular blockade, allowing for increased first pass success of endotracheal intubation.
  • Post-intubation analgesia and sedation is a method of controlling pain, agitation and medically induced amnesia for major trauma patients.

 

Consensus Statements:

 

  • A provincially standardized, evidence-based guideline for Rapid Sequence Intubation should be available in all NB Trauma Centres (Appendix A).
  • Similarly, a provincially standardized, evidence-based guideline for Post-Intubation Analgesia and Sedation should be available in the Emergency Department of all NB Trauma Centres (Appendix B).
  • In addition to standardized, evidence-based guidelines, a provincially standardized equipment layout is recommended to optimize the preparation for RSI (Appendix C).
  • Ambulance New Brunswick should ensure consistency with the provincially standardized guidelines for RSI and Post-Intubation Sedation and Analgesia in procedures for Ambulance New Brunswick’s Air Medical Crew.
  • RSI should not be considered or applied for trauma patients who are in cardiac arrest or who are apneic.
  • RSI should not be considered in patients with a predicted difficult airway.
  • RSI should be considered for all trauma patients meeting the following:
    • GCS < 8, quickly deteriorating GCS or loss of airway protection
    • Facial trauma with poor airway control
    • Burns with suspected inhalation injury
    • Respiratory failure
    • Hypoxia
    • Persistent or uncompensated shock (reduction of respiratory efforts)
    • Agitation with possible injury to self or others
    • Potential for eventual respiratory compromise
    • Possible respiratory and/or neurological deterioration during prolonged transport
    • Transport in a confined space with limited resources
  • In addition to the above, RSI Guidelines should include
    • Assessment of the possibility of a difficult intubation
    • Troubleshooting
    • Immediate reference to post-intubation analgesia and sedation
  • In addition to standardized, evidence-based guidelines, a provincially standardized pre-induction checklist is recommended to optimize the preparation for RSI (Appendix D)

 


 

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