CASE 1

A patient was scheduled for a laparoscopic sterilisation procedure. On insufflation of the abdomen the patient became profoundly bradycardic and cardiac output was lost. CPR was commenced and the cardiac arrest team attended. An ultrasound scan by the surgeon ruled out haemorrhage and the consensus was that anaphylaxis was the cause of the cardiac arrest and treatment instituted accordingly. A bedside ECHO showed diminished function. The patient was transferred to ITU.

CASE2

At the end of a procedure after sugammadex had been given, the patient began coughing and biting on the ETT and suddenly became bradycardic. Atropine was administered after which a short episode of left bundle branch block (LBBB) or ventricular tachycardia (VT) was followed by a supraventricular tachycardia associated Hypotension was resistant to metaraminol and ephedrine and required adrenaline and a phenylephrine infusion. An ECHO showed a collapsed RV and a poorly contracting left ventricle. the patient was treated for anaphylaxis and transferred to ITU.

Commentary

These two cases illustrate how challenging making a diagnosis in an emergency situation can be. In case one although bradycardia can be a feature of anaphylaxis (reported in NAP6),¹ a reflex bradycardia leading to cardiac arrest in this situation was highlighted in NAP7.² In the second case either sensitivity to sugammadex or rapid reversal/ negative pressure pulmonary oedema may have been the cause.

One of the messages from NAP 6 was to include anaphylaxis in the differential diagnosis of perioperative collapse and refer patients to specialist clinics. However, the assessors of NAP7 disagreed with the diagnosis of anaphylaxis in 50% cases implying over-diagnosis. 

Anaphylaxis should always be included in the differential diagnosis of peri-operative collapse, but other causes should also be considered

References

1. Royal College of Anaesthetists. NAP6 Perioperative Anaphylaxis, London 2018
2. Royal College of Anaesthetists. At the Heart of the Matter. Report and findings of the 7th National Audit Project of the Royal College of Anaesthetists examining Perioperative Cardiac Arrest, London, 2023