Collapse in the waiting room, three days into a diarrhoeal illness

34-year-old woman. Collapse in the waiting room, three days into a diarrhoeal illness

Takes citalopram 40 mg daily for depression. Three days of vomiting and diarrhoea after a family barbecue, eating and drinking almost nothing. Given ondansetron 4 mg intravenously at triage an hour ago.

Stage 1 of 2

Nkiru Eze slid off her chair in the waiting room and was unresponsive for about twenty seconds before coming round on the floor, confused for a minute and then back to herself. She had been put on a monitor while she waited for fluids, and this is the strip the nurse printed from it. She is now awake, apologetic and asking to go home.

Tracing 1 of 2 for the quiz “Collapse in the waiting room, three days into a diarrhoeal illness”. — Monitor strip printed from the moment of the collapse, 25 mm/s, 10 mm/mV. Open this tracing in the studio

What does the strip show?

AAtrial fibrillation with aberrant conduction Your answer
BPolymorphic ventricular tachycardia Correct answer Your answer
CMonomorphic ventricular tachycardia Your answer
DMovement artifact during the collapse Your answer

She has a pulse and is talking. What next?

ARefer for urgent angiography as the cause of the arrhythmia Your answer
BAmiodarone 300 mg intravenously to prevent further runs Your answer
CMeasure the QT on a resting tracing and check magnesium and potassium Correct answer Your answer
DLidocaine 100 mg intravenously to prevent further runs Your answer

Stage 2 of 2

Potassium is 2.9 mmol/L, magnesium 0.58 mmol/L and creatinine 104 umol/L against a baseline of 62. She has had no further episodes on the monitor. This twelve-lead was recorded while the bloods were being chased.

Tracing 2 of 2 for the quiz “Collapse in the waiting room, three days into a diarrhoeal illness”. — Twelve-lead recorded after the episode, 25 mm/s, 10 mm/mV. Open this tracing in the studio

Observations

HR: 92
SpO₂ (%): 98
Respiratory rate: 17
Temperature (°C): 36.8
Systolic BP (mmHg): 106
Diastolic BP (mmHg): 64

Bloods

Magnesium (mmol/L): 0.58
Potassium (mmol/L): 2.9
Creatinine (umol/L): 104
Calcium, adjusted (mmol/L): 2.31

What does the twelve-lead show?

APeaked T waves on a narrow base Your answer
BAnterolateral ischaemia with T-wave inversion Your answer
CA normal tracing for a rate of 92 Your answer
DProlonged repolarisation with flattened T waves and U waves Correct answer Your answer

Which of her drugs has to stop?

ANeither, as the potassium accounts for the finding Your answer
BCitalopram alone, as one dose of ondansetron cannot matter Your answer
COndansetron alone, as citalopram does not affect the QT Your answer
DCitalopram and ondansetron Correct answer Your answer

Collapse in the waiting room, three days into a diarrhoeal illness

The case

On arrival

Observations

Bloods

Diagnosis

Discussion