KATHRYN BULL · Prevention of Future Deaths report

KATHRYN BULL, then aged 61 years, died on 4 December 2014. An investigation into her death, and then an inquest was opened. The inquest into Mrs Bull's death was resumed, and concluded, by myself on 27 April 2016.

The medical cause of Mrs Bull's death was:

1.a Multi-organ failure;
1.b Hyperammonaemia syndrome;
1.c Morbid obesity and gastric bypass surgery.

The conclusion as to the cause of death was a narrative one to the effect that Mrs Bull died as a result of an extremely rare complication of gastric bypass surgery.

The circumstances of death are as follows:
(1) Mrs Bull was morbidly obese. On medical advice she had had a gastric bypass operation on 19 January 2014.
(2) Her immediate post-operative recovery was good and she began a liquid diet.
(3) However she gradually found it hard to tolerate the solid food diet that she was advised to follow and often only felt able to eat 2 meals a day not 3.
(4) She complained of dizziness, lethargy, vomiting and ‘blacking out’. These are all unremarkable symptoms of gastric bypass surgery and so did not trigger any concerns in the team monitoring her follow up from the surgery.
(5) By October 2014 she was rarely leaving the house.
(6) On 19 November 2014 she fell at home and was admitted to Lewisham and Greenwich Hospital.
(7) The hospital staff were unsure of the cause of her illness but suspected some form of endocrine or failure secondary to prolonged malnutrition and deficiency in trace elements.
(8) Her conscious state fluctuated.
(9) By 26 November 2014 her ammonia level had risen to 226 µmol/L (where a level of 112 µmol/L could lead to a deranged cerebral state).
(10) She became less conscious and required intubation.
(11) She deteriorated further and suffered a cardiac arrest on 4 December 2014, from which she could not be resuscitated. She was pronounced dead at 3.30 pm that day.

(1) I accepted the evidence from ████████ and multi-organ failure, ████████ to the effect that the medical cause of Mrs Bull's death was multi-organ failure, caused by hyperammonaemia syndrome, which on the balance of probabilities had been caused by morbid obesity and gastric bypass surgery.
(2) The pathologists, ████████ (the gastric bypass consultant who performed the surgery on Mrs Bull) and ████████ (the consultant intensivist who treated her in hospital) confirmed that hyperammonaemia syndrome has been identified as an adverse consequence of gastric bypass surgery.
(3) However this is extremely rare: there appear to have been only 25 or so reported cases worldwide¹. Very little appears to be known about the condition and so the symptoms are not well understood.