Massive Ketonuria During Sedation with Propofol in a 12 Year Old Girl with Severe Head Trauma

Severe ketonuria developed during sedation with propofol in a 12 year old girl with brain injury. Deep sedation with propofol (5.1 mg/kg/h) was required because of agitation and severe intracranial hypertension; as a part of our management protocol, glucose intake was restricted to 5 Kcal/h. After 18 hours of propofol infusion there was intense ketonuria (8+ by Ketostix) without any evidence of metabolic acidosis (pH, HCO3- and anion gap were within normal values). At this time, indirect calorimetry (Deltatrac) confirmed that energy expenditure was principally based on fat consumption (70% of energy expenditure). Lowering the propofol infusion rate and increasing glucose intake reduced fat consumption to 39% within 8 hours: at this time, Ketostix was negative for ketone bodies. This case illustrates a potential risk of ketonuria during prolonged sedation with propofol (a 10% solution of intralipid), particularly if glucose intake is restricted. Monitoring urinary ketone bodies is recommended under these circumstances.