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Management of Supraventricular Tachycardia (SVT) in Pregnancy

 

Management of Supraventricular Tachycardia (SVT) in Pregnancy

Medical Student Clinical Pearl

 

Tyson Fitzherbert, DMNB Class of 2024

Reviewed by Dr. Luke Taylor and Dr. David Lewis

 


Case:

A 30-year-old pregnant (32 weeks) female presents to the emergency department with palpitations and chest discomfort. On ECG they are diagnosed with supraventricular tachycardia, a narrow complex arrythmia – how would you proceed?

 


Introduction:

Pregnant women have a higher incidence of cardiac arrhythmias. The exact mechanism of increased arrhythmia burden during pregnancy is unclear, but has been attributed to hemodynamic, hormonal, and autonomic changes related to pregnancy. A common arrhythmia in pregnancy is supraventricular tachycardia (SVT). SVT is a dysrhythmia originating at or above the atrioventricular (AV) node and is defined by a narrow complex (QRS < 120 milliseconds) at a rate > 100 beats per minute (bpm). The presentations of SVT in pregnancy are the same as the nonpregnant state and include symptoms of palpitations that may be associated with presyncope, syncope, dyspnea, and/or chest pain. Diagnosis is confirmed by electrocardiogram (ECG).

 


Figure 1: Rhythm strip demonstrating a regular, narrow-complex tachycardia, or supraventricular tachycardia (SVT).

In general, the approach to the treatment of arrhythmias in pregnancy is similar to that in the nonpregnant patient. However, due to the theoretical or known adverse effects of antiarrhythmic drugs on the fetus, antiarrhythmic drugs are often reserved for the treatment of arrhythmias associated with clinically significant symptoms or hemodynamic compromise. Below is a detailed description of the management of SVT in pregnancy.

 


Management:

Figure 2: Treatment algorithm for SVT in pregnancy.

 


General Considerations:

  • Non‐pharmacological treatment including vagal manoeuvres such as carotid massage and Valsalva manoeuvre are well tolerated and aid in management.
  • Intravenous adenosine can be used in all three trimesters, including labor.
  • Electrical cardioversion is an effective treatment method for hemodynamically unstable or drug-refractory patients, which has proven to be safe in all three trimesters, including labor. There are some examples of this leading to pre-term labor in the third trimester.
  • AV nodal blocking agents and anti-arrhythmic agents may be considered for cardioversion; see table below for effects in pregnancy and breast feeding.

 

 


Case Continued:

A modified Valsalva manoeuvre is performed with resolution to sinus rhythm after 2 attempts. The patient is discharged with OBGYN follow-up.

https://sjrhem.ca/modified-valsalva-maneuver-in-the-treatment-of-svt-revert-trial/

 


Further Reading


References:

  1. Patti L, Ashurst JV. Supraventricular Tachycardia. [Updated 2022 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www-ncbi-nlm-nih-gov.ezproxy.library.dal.ca/books/NBK441972/
  2. UpToDate – https://www.uptodate.com/contents/supraventricular-arrhythmias-during-pregnancy#H11407709
  3. Ibetoh CN, Stratulat E, Liu F, Wuni GY, Bahuva R, Shafiq MA, Gattas BS, Gordon DK. Supraventricular Tachycardia in Pregnancy: Gestational and Labor Differences in Treatment. Cureus. 2021 Oct 4;13(10):e18479. doi: 10.7759/cureus.18479. PMID: 34659918; PMCID: PMC8494174. https://www-ncbi-nlm-nih-gov.ezproxy.library.dal.ca/pmc/articles/PMC8494174/
  4. Ramlakhan KP, Kauling RM, Schenkelaars N, et al, Supraventricular arrhythmia in pregnancy, Heart 2022;108:1674-1681. https://heart.bmj.com/content/early/2022/01/26/heartjnl-2021-320451#T2
  5. Goyal A, Hill J, Singhal M. Pharmacological Cardioversion. [Updated 2022 Jul 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www-ncbi-nlm-nih-gov.ezproxy.library.dal.ca/books/NBK470536/
  6. Vaibhav R. Vaidya, Nandini S. Mehra, Alan M. Sugrue, Samuel J. Asirvatham, Chapter 60 – Supraventricular tachycardia in pregnancy, Sex and Cardiac Electrophysiology. https://www-sciencedirect-com.ezproxy.library.dal.ca/science/article/pii/B9780128177280000607

 

 

 

 

 

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Pediatric Hip Dislocation & Reduction

Pediatric Hip Dislocation & Reduction

Resident Clinical Pearl (RCP) – November 2022

Dr. Nick Byers , R2 iFMEM, Dalhousie University, Saint John, New Brunswick

Reviewed/Edited by Dr. Brian Ramrattan


Case:
A 10 year old presents to the local emergency department after playing with their sibling. The child was “tackled” from behind. A history and physical exam inform you that the child has been healthy until now with a completely uneventful childhood. They are normal, healthy body habitus and laying on their right side, a pillow between their flexed left knee & hip, and straight right leg. This is the only position of comfort for the child. Neurovascular exam is normal and the child refuses to let you move the leg at all. Foot and ankle move normally. Xrays were obtained promptly. A dislocated hip was readily identified (note the arrow sign below).


Greater than 85% of traumatic pediatric hip dislocations are posterior. Male children are at a greater risk by a 4:1 ratio, and in younger patients, they often occur with minimal force, whereas older children tend to require much greater forces due to the strength of structures surrounding the joint. Fractures can be an associated injury, though it was not in this case. A general triad to consider when evaluating for posterior dislocation is an adducted, shortened, and internally rotated leg as seen below:


Treatment:

A simple dislocation should be treated with closed reduction under sedation, ideally within six hours of injury to reduce the risk of osteonecrosis of the femoral head.


Reduction techniques:

There are many reduction techniques discussed in the literature. Most involve in-line traction of the femur with abduction and external rotation as the leg lengthens, with counter-traction (or downward pressure) placed on the pelvis. This allows for the femoral head to enter the acetabulum gently.

A quick review of technique with attending staff present on shift included the following three options:

  1. The Allis maneuver (https://www.youtube.com/watch?v=zmk3vafjAd4): The physician stands on the stretcher with arms hooked under the flexed knee & hip (both at 90o) on the injured side and an assistant provides downward pressure on the pelvis. Hip extension and external rotation can be applied as the hip reduces.

2.  The Captain Morgan technique (https://www.youtube.com/watch?v=lQMWaFX-MeQ&t=6s): The physician flexes the injured hip and knee to 90o and places their foot on the stretcher at the injured hip of the patient, their knee under the patients. They then grasp the patient’s leg with one hand under the popliteal fossa and one at the ankle. With counter-traction/downward pressure on the pelvis by an assistant, the physician plantar-flexes their foot to put traction on the patient’s femur. External rotation and abduction can be applied with the lower leg as the hip is reduced.

3. The cannon technique: The stretcher is raised and the patient’s knee and hip are flexed to 90o with the popliteal fossa sitting directly over the physician’s shoulder, hands on the patient’s ankle (while facing the patients feet). An assistant stabilizes and provides downward pressure on the pelvis. The physician slowly stands up straight providing in-line traction on the femur until the hip is reduced.


Case Conclusion:

Once x-rays confirmed a posterior hip dislocation, closed reduction under sedation in the emergency department was performed by a resident and staff physician using the cannon technique. Post-reduction films and repeat neurovascular exams were normal and follow-up with orthopedics was in place before discharge home.

Post reduction film:


References:

https://www.merckmanuals.com/professional/injuries-poisoning/dislocations/hip-dislocations

https://www.emnote.org/emnotes/captain-morgan-hip-reduction-technique

CASTED course manual, Arun Sayal

Traumatic hip dislocation during childhood. A case report and review of the literature. American Journal of Orthopedics (Belle Mead, N.J.), 01 Sep 1996, 25(9):645-649

https://usmlepathslides.tumblr.com/post/64398003332/posterior-hip-dislocation-posterior-hip

https://posna.org/Physician-Education/Study-Guide/Hip-Dislocations-Traumatic

https://www.ochsnerjournal.org/content/18/3/242/tab-figures-data

https://coreem.net/core/hip-dislocation/

https://westjem.com/case-report/emergency-physician-reduction-of-pediatric-hip-dislocation.html

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Vascular Access In Children: Solve the Puzzle

 

Dr. Rawan Alrashed (@rawalrashed)

PEM Physician

PoCUS Fellow

Reviewed and edited by: Dr. David Lewis

 

Background

Pediatric vascular access is one of the challenging skills in the medical field especially during an emergency, different guidelines have been established to facilitate the choice of the proper IV access one of which is the miniMAGIC that was published in 2020.1 Choosing the right access is crucial for success taking in consideration the urgency of access, patient safety, infused fluid characteristic  to determine the right one especially with a peripheral IV catheter failure rate of 77% in the first attempt.2 Difficult intravenous Access score (DIVA) is one of the tool that can be used to evaluate the feasibility of a peripheral IV and accordingly, the best next step for IV line insertion where Subjects with a DIVA score of 4 or more were more than 50% likely to have failed intravenous placement on first attempt.3

 

Figure-1: DIVA score.4

Types of vascular access

  • Peripheral IV catheters (PIVCS)
  • Intraosseous Access
  • Central Venous Catheters (CVCs) (Non-tunneled) 
  • US guided Access
  • Umbilical Catheter
  • Surgical cutdown

 

Figure 2: Vascular Access Locations.5

Consideration in pediatrics4

  • Pain management is a critical step for the success of IV cannulation

Multiple choices are available starting from non-pharmacological distraction technique and non-nutritive sucking to the utilization of local anesthetic such as EMLA and LMX as well the needle-free lidocaine jet-injection

  • Enhancing visualization of vein by using tourniquet, transilluminator with any available light source.
  • Ultrasound guided peripheral IV access is the recommended current practice in difficult access.
  • Ultrasound guided central IV access is the standard of care currently in comparison to anatomical landmark in critical care setting.

Indication of IV access

Patient resuscitation.

Delivering fluids, medication, Blood sampling.

Hemodynamics monitoring as well arterial blood gas.

Contraindications

Infection at the insertion site.

Thrombosis of the vein.

Bleeding diathesis in central line is a relative contraindication.

In IO Access, fracture on the same bone as well pathological disorder predisposing to fractures is a contraindication.

Peripheral IV catheter (PIVC)

Different veins can be used for PIVC starting with dorsal veins of the hand, then the feet and then proceeding to other choices including scalp vein in infants, external jugular vein, antecubital and the great saphenous vein as in Figure-2.5

Technique:5

  1. Prepare instruments: cleansing solution, tourniquet, catheter needle, connecting tube, flush, dressing, gauze, and stabilizer tape.
  2. Size of catheter as in the table: utilize the smallest gauge and shortest catheter as possible with exception in resuscitation where larger bore gauge is preferable or in case of midline cannulation where longer catheter is preferable.
  3. Apply tourniquet proximal to the site of insertion to enhance visualization
  4. Identify proper vein by visualization, palpation and utilizing the transilluminator or infrared light
  5. Clean the skin as per the facility protocol
  6. Hold the needle between the thumb and forefinger with the dominant hand and stretch the skin with the other hand
  7. Enter with an angle of 10-30 degree then if blood seen shallow your angle to advance 1-2 mm then advance the catheter and once in pull your needle or retract it.
  8. Flush to confirm patency and no swelling at the site then stabilize your catheter

 

Neonate  Infant   Children Length
PIV 24-26G 22G 20G 2-6cm
Midline Access 22G 22G 20G 15-30cm

 

Table-1: Size of PIV catheter.

 

US guided peripheral vascular access

A recent RCT by Vinograd et.al. evaluated 167 children showed 85% success rate of first attempt with US guidance compared to 45% with traditional methods. Also US guidance resulted in shorter cannulation time, less redirection and fewer attempts.6 

Important consideration in US- guided PIV

  • The diameter and depth of the vein have been found determinate factors for success of cannulation in adult studies where very superficial (< 0.3 cm) and very deep (> 1.5 cm) veins are difficult to cannulate.7
  • The suggested veins are the cephalic vein in the forearm or the saphenous vein at the medial malleolus, while the antecubital vein might be an easy approach but the risk of brachial artery cannulation and the elbow bending make it less favorable. 7

Technique 7

  • Use a linear probe with 5-15 MHz ( Alternatively a hockey stick or MicroConvex might be useful)
  • Identify the vein and assess patency by being compressible and non pulsatile, for further confirmation utilize color or pulse wave doppler with augmentation to identify low status flow.

Longer catheter are preferable when using ultrasound guided insertion especially with a vein deeper then 0.5 cm to minimize the risk of dislodgment and infiltration (suggested to be longer than 2 cm). In a pilot study by Paladini, long catheter > 6 cm were associated with lower risk of failure in pediatric patients more than 10 years comparable to the short one <6 cm.8

  • Static or dynamic guidance are acceptable with preference of the latter. 
  • Two approach technique available with best outcome observed with out-of-plane in PIVC.

 

Out-of-plane (Short-Axis):
  • Consider using the middle point on the ultrasound machine to enhance alignment
  • The US wave perpendicular at right angle to the vessel.
  • The needle is inserted close to the probe at 20-30o angle then advance with meet and greet technique or dynamic needle tip positioning technique as in video

 

 

Pitfalls:

  • The needle shaft might be misidentified as the needle tip thus the importance of advancing the probe then the needle to maintain visualization of the tip only.  Also sweeping in the same plane can help to follow the needle proximal and distal to confirm the tip from the shaft.
  • Risk of posterior wall penetration and failure of cannulation.

 

In-Plane (Long-Axis):
  • The US beam is parallel to the vessel.
  • The whole needle shaft is visualized during insertion and advancement to the vein.
  • To facilitate visualization of needle “Ski left” technique can be used.

 

 

Pitfalls:

  • Maintaining the transducer static without any movement is difficult in small children as any movement would lead to loss of needle visualization, thus insertion will not be accurate (side lobe artifact)

No evidence of preferable technique in pediatrics but in adults out-of-plane proven to be superior for PIVC insertion.

 

How to Use US for PIVC:

https://www.coreultrasound.com/ultrasound-guided-peripheral-iv-access/

 

Intraosseous Access

It’s considered the best alternative IV access in emergencies (peri-arrest and arrest condition) after 2 failed attempts of PIVC within 60-90 seconds, AHA recommends IO catheter as first line access in cardiac arrest. Still the outcome of out of hospital cardiac arrest and best access need more delineation.4,5

Technique4

  • IO access can be accomplished using a manual needle or battery powered device such as EZ-IO or even a regular large bore needle.
  • Place the knee in slight flexion with padding.
  • Clean the skin and consider analgesia according to the urgency of the situation.
  • Insert the needle at 900 over the skin.
  • Remove the stylet and aspirate then infuse saline.
  • Confirmation of proper insertion by the needle standing still even if no backflow seen with lack of extravasation during fluid infusion.

Figure-2 (on green)  shows the possible site for IO insertion where the commonest one is the proximal tibial shaft about 1-2 cm from the tibial tuberosity avoiding the growth plate.

Complication4

  • IO needle is a temporary access that can not last for more than 24 hours
  • Longer use can predispose the child to complication including infection, thrombosis, fat embolism
  • Other complications of insertion include through-and-through penetration of the bone, physeal plate injury, pressure necrosis of the skin, compartment syndrome, osteomyelitis, subcutaneous abscess

 

Confirmation of IO by POCUS2

  • Use linear probe distal to the insertion site
  • Apply color doppler and observe for saline flush site
  • If above the bony cortical site or lateral or deep may indicate misplacement

 

Figure-3: POCUS confirmation of IO site.

 

 

Central IV Catheter (CIVC)

This an alternative longer duration route that can be utilized as an emergency line but less favorable compared to the IO during initial resuscitation. It is still considered a good choice in ill patients with difficulty of PIVC and failure of US guided peripheral access as well IO when fluid, high concentrated electrolytes and vasopressors are needed.4

The common site for insertion of non-tunneled CVC in pediatric is the internal jugular in critical care setting with higher success rate compared to femoral vein9 , but the femoral vein might be the first choice in PEM as it’s easily accessible and don’t interfere with resuscitation measures.10

Technique10

Always prepare your equipment and check them, also get consent when possible before attempting a central line

 

Age(years) weight (kg) Catheter gauge French gauge length (cm)
<1y 4-8 24 3 5-12
<1y 5-10 22 3-3.5 5-12
1-3y 10-15 20 4 5-15
3-8y 15-30 18-20 4-5 5-25
>8y 30-70 16-20 5-8 5-30

Table-2: CVC sizes.4

Anatomical Landmark5

Internal Jugular vein:

  • Under aseptic technique with proper draping, put the patient in Trendelenburg position and turn the head slightly to the other side.
  • Use the medial head of the sternocleidomastoid muscle or between the tow head at the level of the thyroid cartilage just lateral to the carotid artery guide your needle on a 45o  toward the ipsilateral nipple while aspirating during insertion until you feel loss of resistance and have a backflow.
  • follow with the guidewire into your needle and then dilator
  • Complete by  inserting the catheter line and fixing it.

Subclavian vein:

Directly below the clavicle at the junction of the lateral one third with the medial two third directing the needle toward the sternal notch

Femoral vein:

1-2 cm below the inguinal ligament medial to the femoral artery, guide the needle toward the umbilicus

 

US Guided CVC

The use of ultrasound guided insertion is considered the standard of care for central line insertion. Ultrasound use reduces the number of attempts and procedure duration, increases the successful insertion rate, and reduces complications compared to the skin surface anatomic landmarks technique.9

This can facilitate visualization, increase the success rate with 95% first attempt success rate of ultrasound-guided venous punctures compared to 34% of the anatomical landmark and decrease the rate of complication that would occur with the anatomical landmark.11

 

  • Always start by identifying the land mark on US before starting the procedure (vein is compressible and less pulsatile than the adjacent artery)
  • Probe position according to the site of insertion.  
  • Prepare the patient under aseptic technique as well the probe with sterile sheet and the ultrasound counsel unless you have assistance.
  • Infiltrate local anesthesia to the skin puncture site.
  • Utilize sterile gel on the outside of the sterile sheet or alternatively sterile water or saline
  • Use an out of plane technique to guide the needle into the vein (higher success rate).
  • Start by inserting the needle at 45 degree angle from the probe and the same distance away as the vein from the skin
  • Follow the dynamic needle tip positioning technique (meet &greet) to keep visualizing the needle tip while guiding it toward the vein
  • If confusing the needle tip with the shaft try to slide the probe proximal and distal until confirmation
  • Use the same steps in aspirating while inserting until having a backflow and confirming the needle is inside the vein lumen
  • Complete the steps as before and confirm the position of the guidewire by ultrasound.
  • Insert the central catheter and fix it with sutures and transparent dressing.

 

Internal jugular vein:

Subclavian vein

Femoral vein

 

Complication12

Confirm proper placement by US as well X-Ray

R/O complication as pneumothorax, hemothorax or hematoma, mis-displacement

Artery puncture, air embolism, thoracic duct injury, arrhythmia are possible complications.

 

Umbilical Catheter

  • Can be used in neonate up to 7 days old.
  • Apply tourniquet to umbilical stump then cut the upper dried part.
  • Identify the vein which is single and thin walled while arteries are two and thick wall.
  • Stent the vessel with a forceps then insert the catheter up to 3-4 cm until blood return (Do NOT advance further as the risk of complication and adverse events are high)

 

Venous Cutdown

It is uncommon access in pediatric patients with the availability of IO needle, if needed the classic site is the saphenous vein which is 2 cm superior and anterior to the medial malleolus.

 

 

Resources:

  1. Ullman AJ, Bernstein SJ, Brown E, et al. The Michigan Appropriateness Guide for Intravenous Catheters in Pediatrics: miniMAGIC. Pediatrics. 2020;145(Suppl 3):S269-S284. doi:10.1542/peds.2019-3474I.
  2. Delacruz N, Malia L, Dessie A. Point-of-Care Ultrasound for the Evaluation and Management of Febrile Infants. Pediatr Emerg Care. 2021;37(12):e886-e892. doi:10.1097/PEC.0000000000002300.
  3. Yen K, Riegert A, Gorelick MH. Derivation of the DIVA score: a clinical prediction rule for the identification of children with difficult intravenous access. Pediatr Emerg Care. 2008;24(3):143-147. doi:10.1097/PEC.0b013e3181666f32.
  4. Whitney R, Langhan M. Vascular Access in Pediatric Patients in the Emergency Department: Types of Access, Indications, and Complications. Pediatr Emerg Med Pract. 2017;14(6):1-20.
  5. Naik VM, Mantha SSP, Rayani BK. Vascular access in children. Indian J Anaesth. 2019;63(9):737-745. doi:10.4103/ija.IJA_489_19.
  6. Vinograd AM, Chen AE, Woodford AL, et al. Ultrasonographic guidance to improve first-attempt success in children with predicted difficult intravenous access in the emergency department: a randomized controlled trial. Ann Emerg Med. 2019;74:19–27.
  7. Nakayama Y, Takeshita J, Nakajima Y, Shime N. Ultrasound-guided peripheral vascular catheterization in pediatric patients: a narrative review. Crit Care. 2020;24(1):592. Published 2020 Sep 30. doi:10.1186/s13054-020-03305-7.
  8. Paladini A, Chiaretti A, Sellasie KW, Pittiruti M, Vento G. Ultrasound-guided placement of long peripheral cannulas in children over the age of 10 years admitted to the emergency department: a pilot study. BMJ Paediatr Open. 2018;2(1):e000244. Published 2018 Mar 28. doi:10.1136/bmjpo-2017-000244.
  9. Pellegrini S, Rodríguez R, Lenz M, et al. Experience with ultrasound use in central venous catheterization (jugular-femoral) in pediatric patients in an intensive care unit. Arch Argent Pediatr. 2022;120(3):167-173. doi:10.5546/aap.2022.eng.167.
  10. Skippen P, Kissoon N. Ultrasound guidance for central vascular access in the pediatric emergency department. Pediatr Emerg Care. 2007;23(3):203-207. doi:10.1097/PEC.0b013e3180467780.
  11. De Souza TH, Brandão MB, Santos TM, Pereira RM, Nogueira RJ. Ultrasound guidance for internal jugular vein cannulation in PICU: a randomised controlled trial. Arch Dis Child. 2018; 103(10):952-6.
  12. Georgeades C, Rothstein AE, Plunk MR, Arendonk KV. Iatrogenic vascular trauma and complications of vascular access in children. Semin Pediatr Surg. 2021;30(6):151122. doi:10.1016/j.sempedsurg.2021.151122

 

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Pediatric Appendicitis PoCUS – Deep Dive – Don’t Dive Deep

PoCUS Fellow Pearl

Dr. Rawan Alrashed 

Pediatric Emergency Physician

Dalhousie PoCUS Fellow

Dalhousie University Department of Emergency Medicine

@Loolla1988

 

Reviewed & Edited by Dr David Lewis (@e_med_doc)

All case histories are illustrative and not based on any individual

 


Case:

12 years old female, previously healthy, presented to the ED with 1 day history of abdominal pain persistent, mainly in the lower abdomen, nauseated, with loss of appetite, no vomiting, no bowel motion, low grade fever, by exam she was distress in pain with tachycardia abdominal exam showed periumbilical and RLQ tenderness. Labs requested.

Awaiting the results, thinking of differential diagnosis and best imaging study….

Would POCUS help in the diagnostic process??

 


Background:

In children, acute appendicitis constitutes 1-8% of the abdominal pain diagnosis and is the most common condition requiring emergency surgery. The potential for morbidity and mortality from perforation of the appendix necessitates prompt diagnosis. Although a variety of clinical scoring systems have been developed, there is still no consensus on clinical, laboratory, and imaging criteria for diagnosing appendicitis, which poses a dilemma for the emergency clinician (1). The clinical presentation of children with appendicitis varies from that of adults which makes it more difficult to diagnose it. Multiple scoring systems (Pediatric Appendicitis score, Alvarado score, Pediatric Appendicitis risk calculator) were developed and externally validated with varying degree of sensitivity and specificity (2).

 


Anatomy:

The appendix is a blind-ended tubular structure that arises from the posteromedial aspect of the cecum, proximal to the ileocecal valve. The average length of the appendix varies from neonates to adults, ranging from 4.5 mm to 9.5 mm. The orientation of the appendix can be retrocecal, subcecal, preileal, retroileal, or in a pelvic site (1).

 

From Wikipedia

Pathology:

Appendicitis is a result of obstruction of the appendiceal lumen. Obstruction can occur secondary to stones, fecaliths, or other processes that inflame the lymphoid tissue. 

Pathology review


Diagnostic Imaging

Imaging Study

Sensitivity

Specificity

US

88%

94%

CT

94%

95%

MRI

96%

96%

 (Benabbas, 2017 (2))                                                                                 


PoCUS Anatomy

Cecum (C) is the most lateral structure in the RLQ, it’s a gas-fecal filled (dirty shadow) identified by following the haustra on the ascending colon caudally

Terminal ileum (TI) is a smooth wall that is fluid filled showing peristaltic movement and demonstrates valvulae conniventes.

(Ref – 9,12)

 

Cecum and terminal Ileum – Radiology Assistant
Colon – haustra
Small bowel – valvulae conniventes
Ileocecal valve (long arrow), Appendix (short arrow) (Jeffery,2018)
P-Psoas, Iv/a-Iliac vein and artery, Ap – Appendix From The PoCUS Atlas

Gongidi,2017

Normal 5 layers of the Appendix 

a) echogenic mucosa

b) hypoechoic muscularis mucosa

c) echogenic submucosa

d) hypoechoic muscularis propria

e) echogenic serosa


PoCUS Technique 

Use the LINEAR Probe (Curvilinear might be needed in large habitus people)

  • Analgesia First – Start with controlling the PAIN before starting the scan
  • Start by scanning the Maximum point of tenderness at the RLQ
  • Use the GRADED COMPRESSION as a technique to remove bowel gas
  • Scan in both planes (Longitudinal and Transverse) the entire length of appendix
  • Utilize the psoas muscle, iliac vessels and caecum as landmarks by:
    • Identify the iliac vessels
    • Identify the ileum above them then ileocecal junction
    • Scan inferiorly to the base of the caecum (appendix should be seen here)

If appendix is not visualized use the systematic approach (suggested by Sivitiz et al)

  • Move the probe laterally, until identify the ascending colon and lateral abdominal wall 
  • Move the transducer on the lateral border of the cecum.
  • Then, move the transducer medially, across the psoas and iliac vessels.
  • With the psoas muscle and iliac vessels kept in view, move the transducer down into the pelvis and towards the umbilicus at the border of the cecum.
  • If the appendix is not yet visualized, put the probe in the sagittal position, identifying the cecum in the long axis and move the transducer (sweep medially) compressing the cecum against the psoas muscle.

(Ref – 3,5,8)

Adaptations

Retrocecal Appendix

Consider applying pressure dorsally on the patient RLQ from the back. Scan while the patient on left posterior oblique position and scan parasagittal through the right flank in a coronal plane parallel to long axis of the psoas muscle; the appendix will appear anterior to the psoas muscle.  

Pelvic Appendix

Consider using curvilinear transducer. Scan deeper and use the bladder as a window

(Ref 5)


Core Ultrasound  – 5 Min Sono – Appendicitis


PoCUS Findings

Normal Appendix

Primary signs of Appendicitis

Secondary signs

Tubular blind ended structure arising from base of the Caecum

a non compressible appendix

(Target sign)

free Fluid in the right lower quadrant

No peristalsis

appendix wall diameter > 3 mm

echogenic edematous mesenteric fat stranding

Anteroposterior diameter

overall appendiceal diameter

> 6 mm (some reported 7mm)

appendiceal wall hyperemia (ring of fire)

Compressible target sign

ultrasound McBurney’s sign 

abnormal lymph nodes

 

presence of appendicolith

abnormal adjacent bowel, and bowel wall edema

(Ref 4,11)


Normal Appendix


Primary Signs of Appendicitis

 

Non-compressible, Thickened wall, Diameter >6mm
Superficial to Iliac vessels, Non-compressible, Thickened wall
Appendicolith

Secondary Signs of Appendicitis

 

Periappendicular Fluid
Ring of Fire

PoCUS Appendicitis – Evidence

  • A systematic review by Benabbas et al concluded that ED POCUS had 86% sensitivity and 91% specificity which was similar to RUS with sensitivity of 88% and specificity of 94%. POCUS reported as having a positive likelihood ratio of 9.24% and a negative likelihood ratio of 0.17. (2)

  • The American College of Radiology issued appropriateness criteria for imaging in RLQ pain recommending ultrasound as the first line option in children. (4)
  • The utilization of staged imaging approach has led to reduction of CT by 55-63% in different studies considering US (POCUS+ RUS) as first line image and CT used in equivocal cases or non visualized appendix. (6)
  • Elikashvili et al. demonstrated a significantly decreased length of stay for patients with disposition by POCUS compared to radiology (154–288 min) without any cases of missed appendicitis. (14)
  • Abnormal echogenicity or so-called infiltration of peri appendiceal fat has been found to be a particularly useful sign of appendicitis on US. Trout et al. found it to be the only independent statistically significant parameter to predict appendicitis, with a positive odds ratio of greater than 60. (3)

 


Limitations and Pitfalls

  • Operator dependent (level of experience with POCUS determines test acuracy).
  • The duration since the onset of symptoms (around 48 hours was found to be the optimal time to diagnose appendicitis by POCUS)
  • Misidentification of small bowel as the appendix (confirm a blind ended structure to prevent this)
  • Visualization of only the normal portion of a diseased appendix, where inflammation is isolated to the tip (false negative) scan the entire appendix.
  • Misdiagnosing a normal appendix as inflamed secondary to other intra-abdominal processes, such as Crohn’s disease or pelvic inflammatory disease (false positive).
  • Misdiagnosing acute appendicitis based on a diameter greater than 6 mm in an ovoid appearing compressible appendix and/or without any secondary signs of inflammation.
  • It can be difficult to visualize a perforated appendix due to the inability to perform a graded compression exam on a patient with peritonitis. (7)

 


Case Conclusion

PoCUS was performed. The images strongly suggested a diagnosis of appendicitis. A consultative ultrasound was performed in Diagnostic Imaging which confirmed our findings. After surgical consultation the child had an appendectomy and discharged the next day.


Bottom Line

  • Follow a Bayesian approach when using PoCUS to support your diagnosis of appendicitis. Pre-test probability will influence  your staged approach to a child with RLQ pain.
  • Utilize PoCUS and consultative DI Ultrasound to minimize radiation exposure with CT.
  • Review the proposed algorithm as an approach to suspected pediatric appendicitis.
  • Always consider appendicitis mimics in pediatrics (intussusception, IBD, ovarian torsion etc..) – don’t miss these!

 

Adapted from Pediatric Emergency Practice, 2019


References

1) Becker C, Kharbanda A. Acute appendicitis in pediatric patients: an evidence-based review. Pediatr Emerg Med Pract. 2019;16(9):1-20.
2) Benabbas, R., Hanna, M., Shah, J., & Sinert, R. (2017). Diagnostic Accuracy of History, Physical Examination, Laboratory Tests, and Point-of-care Ultrasound for Pediatric Acute Appendicitis in the Emergency Department: A Systematic Review and Meta-analysis. Academic Emergency Medicine, 24(5), 523–551.
3) Swenson DW, Ayyala RS, Sams C, Lee EY. Practical Imaging Strategies for Acute Appendicitis in Children. AJR Am J Roentgenol. 2018;211(4):901-909.
4) Lawton B, Goldstein H, Davis T, Tagg A. Diagnosis of appendicitis in the paediatric emergency department: an update. Curr Opin Pediatr. 2019;31(3):312-316.
5) Berghea-Neamţu, C. T. (2019). The Ultrasonographic Exam for Acute Appendicitis at Patient’s Bed. Acta Medica Transilvanica, 24(4), 48–50.
6) Doniger SJ, Kornblith A. Point-of-Care Ultrasound Integrated Into a Staged Diagnostic Algorithm for Pediatric Appendicitis. Pediatr Emerg Care. 2018;34(2):109-115.
7) Marin JR, Abo AM, Arroyo AC, et al. Pediatric emergency medicine point-of-care ultrasound: summary of the evidence [published correction appears in Crit Ultrasound J. 2017 Dec;9(1):3]. Crit Ultrasound J. 2016;8(1):16.
8) Sivitz AB, Cohen SG, Tejani C. Evaluation of acute appendicitis by pediatric emergency physician sonography. Ann Emerg Med. 2014;64(4):358-364.
9) “US of the GI Tract – Normal Anatomy.” The Radiology Assistant : US of the GI Tract – Normal Anatomy, https://radiologyassistant.nl/abdomen/ultrasound/lk-jg-1-1.
10) Riscinti, Matthew. “Bedside Ultrasound for Acute Appendicitis – Featuring Colorized Images.” TPA, TPA, 10 Jan. 2021, https://www.thepocusatlas.com/new-blog/appendicitis.
11) Gongidi P, Bellah RD. Ultrasound of the pediatric appendix. Pediatr Radiol. 2017;47(9):1091-1100.
12) Jeffrey RB, Wentland AL, Olcott EW. Sonography of the Cecum: Gateway to the Right Lower Quadrant. Ultrasound Q. 2018;34(3):133-140.
13) US probe: Ultrasound for small bowel obstruction. emDOCs.net – Emergency Medicine Education. (2018, March 27), http://www.emdocs.net/us-probe-ultrasound-for-small-bowel-obstruction.
14) Elikashvili I, Tay ET, Tsung JW. The effect of point-of-care ultrasonography on emergency department length of stay and computed tomography utilization in children with suspected appendicitis. Acad Emerg Med. 2014 Feb;21(2):163-70.

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COVID-19 Airway Rounds – Dr. George Kovacs

Thanks to Dr. George Kovacs at DalEM for providing this link to his recent COVID-19 Airway Rounds. This presentation is informative, evidence-based and highly entertaining. SJEM is proud to be part of DalEM and associated with so many great educators.

Supporting material is available here


AIME Airway

Canada’s premium Airway Management course. Visit the website for access to free airway resources and also registration for the courses.

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Code Discussion in the ED

EM Reflections March 2021 – Code Discussion in the ED

Thanks to Dr. Paul Page for leading this month’s discussion.

All cases are imaginary but bring up important learning points.

Authored & Copyedited by Dr. Mandy Peach

 

Case

An 80 yo female is brought in by EMS in respiratory distress. There is a known history of end stage CHF. Collateral from the husband on scene was that his wife has been having increasing shortness of breath for 1 week, increased ankle swelling and was sleeping sitting up in the recliner in the living room. He called EMS today as she could not catch her breath when walking upstairs in the home.

The patient is on CPAP with EMS and has signs of central cyanosis. You direct the RT to switch her to Bipap as she is put on the monitors and a new set of vitals are obtained. You quickly examine the patient and find bilateral pitting edema to the knees and both peripheral and central cyanosis. There are audible crackles throughout both lung fields. You grab your ultrasound probe and find diffuse B-lines bilaterally in the lung fields and a cardiac view demonstrates a severely decreased ejection fraction. The IVC is dilated and not collapsing with respirations. She looks drowsy and is not responding to questions. She is not tolerating Bipap well. Her new vitals are: BP 98/62 HR 112 RR 24 O2 sat 85% on BiPAP T 37.4.

You suspect cardiogenic shock. This patient needs to be intubated. But you stop momentarily – this is an elderly patient with end stage cardiac disease. The prognosis for this patient is likely poor. Is intubation in the best interest of the patient?

This is a scenario we are often placed in as ED physicians. Just because we have the ability to resuscitate a patient doesn’t necessarily mean they will have a positive functional recovery. Here the patient is drowsy and in respiratory distress – she cannot tell us her wishes for care. In many cases, end of life care has not been discussed1 and in this situation the care decisions lie with the family/loved ones or us as physicians.

Current practice is that each patient is a ‘full code’ unless otherwise indicated2. So regardless of age, comorbidities, quality of life – if a deterioration of vital signs is seen every attempt is made to resuscitate this patient regardless of the likelihood of a functional recovery. Unlike the rest of medicine, this care is a ‘one fits all’ approach where initial efforts are carried out regardless of clinical situation. Whether or not this is the right approach is not the focus of discussion. Instead this highlights the importance of advanced care planning and goals of care discussions taking place when a patient is well and normalizing this process.

Back to our patient – they are circling the drain. You ask the medical student working with you to look up the patient chart and see if any previous code discussion has taken place. After a quick review there is no documentation of a code status. Even if there was – would this change your management?

Code discussions are not set in stone. A patient with capacity can change their mind at any time. Loved ones acting as substitute decision makers/power of attorney are also able to make decisions for the patient in the event a patient cannot make decisions for themselves.
Ideally you want to have a discussion with the family to set realistic expectations and together make an informed decision for the patient.

Luckily the husband and patient’s daughter are already in the department. You decide to have a discussion before proceeding with intubation. What are your goals for this discussion3?

  • Choose a quiet location away from the patient
  • Give your clear medical opinion and recommendations rather than options only, this way the family doesn’t feel the decision is completely up to them.
  • Use straight forward language that is easy to understand
  • “Review the risks of progressing to CPR if the patient declines including:
    o Incomplete recovery
    o Prolonged death
    o Uncomfortable investigations and treatments
    o Ventilator dependence”
  • Avoid a power struggle with the family if they choose to go against your recommendations.

What are some barriers we face in the emergency department when discussing and prognosing end of life care with patients or family members3?

We are poor at predicting prognosis, partly because this isn’t within our scope of care in initial resuscitation of patients, but also because there is always uncertainty in medicine – and this should be communicated to the family. As we see elderly or co-morbid patients in the department without a prior code status there may be a feeling that this should be the responsibility of the primary care provider and not the ED doc. Lastly, this is a difficult discussion to have regardless of timing and communicating prognosis may not always go smoothly. We may find ourselves in the same situation as the case above – with a crashing co-morbid patient with no clear goals of care. Unfortunately this is an especially difficult time to have this conversation, but it is a necessary one.

Since this is such a difficult discussion to have, is there any approach that might be helpful3?

Think SILVER

Seeks Information:

  • Elicits information regarding baseline level of function, behaviors, and symptoms that suggest progressive decline
  • Elicits information regarding current diagnosis, prognosis, and treatment plan
  • Elicits information regarding key players in decision making, including family and health care workers
  • Elicits information regarding previous end of life discussions, including advance directives

Life Values:

  • Elicits information regarding the patient’s personality and approach to life
  • Elicits information regarding how the patient views death and dying

Educates/Extends Care:

  • Pr0vides information regarding the patient’s disease process, current condition, and treatment options
  • Explains how end of life decisions will impact further treatment

Responds:

  • Solicits questions from family and offers continued support and availability for further information.”

You have a discussion with the family keeping in mind the above approach. You clearly lay out the poor prognosis and that you would suggest palliating the patient and avoiding any aggressive resuscitation. The daughter is upset and states “So you’re going to do nothing for my mother?”

This is a common misconception – that ‘do not resuscitate’ is the equivalent of doing ‘nothing’. Choosing not to do compressions or intubate a patient is the decision when an arrest or peri-arrest situation arises. However, patients can still receive medical care with goals in mind depending on the clinical situation. For example, using antibiotics in a patient with metastatic cancer who has pneumonia and who is clinically stable. Or in this situation – providing medications and oxygen to ensure a patient is comfortable and without suffering as they near the end of their life.

One approach could be to positively state all the things you will do for her mother, as oppose to what you will not be doing3.

Wording surrounding code status has also moved towards “allowing natural death” instead of “do not resuscitate” – again moving away from the idea that we are not providing a medical service.

You lay out your plan and positively reinforce the care you can provide for the patient. They agree that aggressive care would not be what the patient wanted and they agree to proceed with palliation. The husband asks you how much time she has left, and if they have time to call in family.

What are signs that help predict timing of death3?

Delirium with hypotension and tachycardia: median survival 10 days
Death rattle: medial survival 1 day
Respirations with mandibular movement: median survival 2.5 hours
Cyanosis to extremities: medial survival 1 hour”

Your patient is cyanotic and essentially crashing. You again express that predicting is difficult, but you anticipate she may die soon and you suggest calling in the family.

You discuss interim management of the patient’s symptoms while you await palliative care. As the patient is quite short of breath one of your recommendations is opioids to help. The husband says he does not want opioids given as they will ‘kill her sooner’. How do you respond?

Opiods can help with the sensation of shortness of breath. The doses used for dyspnea are smaller than the doses used for pain.

“Studies have shown that O2 and CO2 levels stay the same despite the decreased respiratory rate associated with opioids. Opioids in the palliative patient are appropriate and ethically permissible as long as the intent is symptoms relief.”3

See the infographic below for symptom management in palliative care patients3. Being familiar with palliative care is pertinent – these patients are ours until consultants take over care, and in current climate often we end up palliating patients.

The husband agrees with your plan. They stay with the wife in the ED and within a short time a bed is available in palliative care. The patient dies comfortably that night. What about if the family wasn’t there? And we had to choose to resuscitate the patient or not?

There is no right answer. Choosing to intubate the patient and have the discussion with family after the fact is one option. Choosing not to intubate the patient and provide conservative management until a discussion can be had is another option. Sometimes these will be patients with end stage disease but the presentation may be a reversible one. Sometimes these will be healthy patients with irreversible presentations.

Regardless, clearly documenting on the chart your rationale and approach can be helpful in laying out your thought process.

These are difficult situations, and at the end of the day you have to be ethically comfortable with your decision. Having open, honest conversations with family/loved ones as outlined above can certainly help us feel at ease with our decisions and help families and patients come to terms with worsening conditions.

 

References and further reading:

Dong, K. CanadiEM Frontline Primer – Advance Care Planning and Goals of Care Review. CanadiEM. 2020. https://canadiem.org/canadiem-frontline-primer-advance-care-planning-and-goals-of-care-review/ (Assessed April 25, 2021)

Kwok, E. From Full Code to No Code. CanadiEM. 2012. https://canadiem.org/from-full-code-to-no-code/. (Assessed April 25, 2021).

Greewal K, Helmin A.Episode 70 End of Life Care in Emergency Medicine. Emergency Medicine Cases. Sept 2015. https://emergencymedicinecases.com/end-of-life-care-in-emergency-medicine/. (Assessed April 25, 2021).

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Congratulations to Dr. Rob Dunfield – CAEP Resident Research Award Winner!

CAEP 2021 Resident Research Award Winner – Dr. Rob Dunfield

A big congratulations goes out to our very own resident researcher, Dr. Rob Dunfield! Dr. Dunfield is a second year resident in the FMEM Program here in Saint John. He is one of seven residents recognized nationally for their excellent research abstract submissions to the annual CAEP conference. Dr. Dunfield’s research project is a secondary study from the SHOC-ED group and is entitled:  “Does IVC Ultrasound independently predict fluid status in spontaneously breathing, undifferentiated hypotensive patients? SHOC-IVC”.

Congratulations again, Dr. Dunfield!

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