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)
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.
