EM Reflections – November 2018

Thanks to Dr. Paul Page for leading the discussions this month

Edited by Dr David Lewis 


Top tips from this month’s rounds:

1. Severe Metabolic Acidosis

2. Ovarian Torsion

3. Acetaminophen Overdose


Severe Metabolic Acidosis with Unexplained Anion Gap

Case: Female presents with reduced LOC, found with large empty bottle of gin. Smells of alcohol. Hypothermic. VS otherwise stable.

VBG: pH – 6.89, pCO2 – 28, bicarb – 6, Lactate – 21

Anion Gap

Anion Gap = Na+ – (Cl- + HCO3-)

An elevated anion gap strongly suggests the presence of a metabolic acidosis. The normal anion gap depends on serum phosphate and serum albumin concentrations. The normal AG = 0.2 x [albumin] (g/L) + 1.5 x [phosphate] (mmol/L)

MDCalc Anion Gap Calculator

Common Causes (MUDPILES):

  • Metformin, Methanol
  • Uremia
  • DKA
  • Pyroglutamic acidosis, paracetamol, phenformin, propylene glycol, paraladehyde
  • Iron, Isoniazid
  • Lactic acidosis
  • Ethylene glycol
  • Salicylates

Dr. Pages’s Tips: Keep toxic alcohols in the differential.  Early antibiotics for possible sepsis. Remember for sick patients to consult early to appropriate services to expedite disposition.  Sick patients take up a lot of nursing resources so also be aware of impact on nursing care and resources with these patients.


Ovarian Torsion

This is a gynae/surgical emergency, delayed diagnosis may lead to loss of ovary. Early diagnostic ultrasound is recommended.

Ovarian torsion is a rare but emergency condition in women. Early diagnosis is necessary to preserve the function of the ovaries and tubes and prevent severe morbidity. Ovarian torsion refers to complete or partial rotation of the adnexal supporting organ with ischemia. It can affect females of all ages.

Presents with acute onset severe lower abdominal pain, with nausea and vomiting.

Benign ovarian cyst > 5cm is the usual cause. Torsion can also occur in normal ovaries, however, particularly in premenarchal girls who have elongated infundibulopelvic ligaments 

Dr. Page’s Tips: Increased risk with large cysts but can occur without cysts as well.Time sensitive dx so need to be vigilant with assessment. When considering as dx need to get U/S arranged and gynaecology consultation. Remember we have 24 hour U/S coverage but we have to ask for the U/S.


Acetaminophen Overdose

Survival from a acetaminophen overdose is generally considered to be 100% in cases receiving NAC within 8 hours of exposure. Efficacy declines after this point. Therefore early recognition is paramount. Don’t miss the treatment window by not considering.

This post from LITFL does a great job outlining the management of Acetaminophen (Paracetamol) toxicity:

Also with have discussed Acetaminophen toxicity in EM reflections in June 2018:

and also in December 2016:

Dr. Page’s Tips: Correlate presentation with timeframe to see if adds up regarding time of OD. When patient being assessed by other services (with primary resident assessment) we need to keep in mind these are still our patients and review to make sure the plan seems appropriate.

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EM Reflections – June 2018

Thanks to Dr. Joanna Middleton for leading the discussions this month

Edited by Dr David Lewis 

 


 

Top tips from this month’s rounds:

Button Battery Ingestions

Acetaminophen Overdose / Poisoning – Delayed Presentation

Transient Ischemic Attack (TIA) – Follow-Up


 

Button Battery Ingestions

Button Battery Ingestion

 

Take Home Points:

  • Button battery ingestions are can potentially be very serious. Necrosis, perforation and erosion into vessels can occur in as little as 2 hours
  • ALL nasal and esophageal button batteries should be removed within 2 hours of presentation to minimize mucosal damage
  • Consider button battery ingestion in children presenting with dysphagia, refusal to eat and hematemesis
  • Co-ingestion of a button battery with a magnet requires emergency removal regardless of where it is in the GI system
  • Early GI consult is advised

The management algorithm form National Capital Poison Center covers all eventualities! (Click to enlarge)

 


 

Acetaminophen Overdose / Poisoning – Delayed Presentation

Take Home Points:

  • N-acetylcystine (NAC) is a safe and effective antidote. Time to NAC is crucial to protect the liver from significant toxicity.
  • Stated timing and dose are often unreliable and this needs to be taken into consideration.
  • NAC is almost 100% effective if administered within 8hrs of ingestion.
  • If time of ingestion is known for certain to be < 4hrs ago – draw blood for level at 4hrs post ingestion and use nomogram to determine who to treat.
  • If time of ingestion is known for certain to be < 8hrs ago – draw blood for level immediately and use nomogram to determine who to treat (provide result can be obtained within 8 hrs – otherwise start NAC pending result)
  • If time of ingestion is known for certain to be > 8hrs and < 24hrsCommence NAC and draw blood for level immediately and use nomogram to determine whether to continue NAC.
  • If time of ingestion is > 24hrs or unknown or ingestion is staggered – Commence NAC and draw blood for level immediately – Consult toxicology for advice – Only if level is undetectable and AST is normal then NAC can be discontinued, otherwise continue NAC and consult.

View the SJRHEM Acetaminophen Poisoning post here (includes Nomograms and NAC dosing):

New Acetaminophen Poisoning Guidelines from the Royal College of EM

See also this useful NEJM Review Article

For Children, this guideline is useful.

  • Presenting between 4-24 hours (Time of ingestion is known)- use nomogram to determine who to treat.


 

  • Presenting after 24 hours or time of ingestion unknown or ingestion spans > 24hrs

From: UpToDate

 


 

Transient Ischemic Attack (TIA) – Admit or Follow-Up

Take Home Points:

  • All TIA patients need an ECG and baseline labs (CSBP recommended labs)
  • Very High Risk TIA Patients (see below) should have a CT/CTA (or MRI/MRA) immediately
  • High Risk TIA Patients (see below) should have a CT/CTA (or MRI/MRA) within 24hrs
  • All TIAs should be followed up in a specialist TIA Clinic
  • TIA’s + large artery stenosis – candidate for early revascularization (the sooner it is done the better the prognosis)

 

Full Canadian Stroke Best Practice Guideline can be viewed here

 

UpToDate: These results suggest that CEA is likely to be of greatest benefit if performed within two weeks of the last neurologic event in patients with ≥70 percent carotid stenosis. For patients with 50 to 69 percent stenosis, CEA may only have benefit if performed within two weeks of the last event.

 

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