Five days post emergency colorectal surgery, an elderly woman, following a brief period of chest pain a few hours earlier, developed progressive hypotension and tachycardia on the ward. She had a background of hypertension, type 2 diabetes and a chronic left foot ulcer. On examination she was found to be clammy, mottled and peripherally vasoconstricted with a GCS of 15/15. Her abdomen was soft and non-tender. Her initial ECG had showed no ischaemic changes and subsequent ECGs showed only a sinus tachycardia.
Initial blood gas analysis showed a metabolic acidosis (pH 7.21 Lactate 2.8mmol/l, HCO3 11.1mmol/l with a pCO2 of 2.7kPa). A starting differential diagnosis of a cardiac event, a pulmonary embolism, critical ischaemia or sepsis related to a hip or foot ulcer were made. Urgent orthopaedic and vascular review were obtained, and it was deemed that neither the hip, ulcer or vascular insufficiency were a likely source for the deterioration. Initially it was planned to transfer her for a CTPA, however she became progressively unstable, was no longer fluid responsive, and was intubated on the ward and transferred to the intensive care unit (ICU) for stabilisation.
On arrival on ICU she continued to deteriorate, and in addition to fluid resuscitation required a high dose noradrenaline infusion to maintain her blood pressure. Broad spectrum antibiotics were started, a bedside echocardiogram and blood tests performed and hydrocortisone started. Her metabolic acidosis continued to deteriorate, subsequent arterial blood gas showed a pH 6.91, Lactate of 13.7mmol/l, HCO3 7.7mmol/l, base excess -25mmol/l with a pCO2 of 5.4kPa. It was decided to correct this acidosis with a bicarbonate infusion and initially 200ml of 8.4% was given over an hour, based on correcting half the calculated bicarbonate deficit (bicarbonate deficit (mmol) = base deficit 0.3xbodyweight(kg)1). The blood gas following this infusion showed improvement in the metabolic acidosis despite the increasing Lactate (pH 7.07, Lac 14.0mmol/l, HCO3 10mmol/l, BE -18.6mmol/l with a pCO2 of 4.85kPa). She continued to deteriorate and the results from her blood tests, troponin and bedside echo suggested a primary myocardial infarction to cause this decline. She was too unstable for primary coronary intervention and her condition continued to deteriorate. She died 6 hours post admission.