The relationship between blood glucose, mean arterial pressure and outcome after severe head injury: an observational study.
METHODS
Hypotension and hyperglycaemia occurring in the first 24h after severe head injury are individually associated with poor outcome but a causal effect has not been proven for either. Their combined effect is unknown and is investigated in this observational study of 338 patients with head injury, a Glasgow coma score (GCS) of 8 or less and requiring mechanical ventilation.


RESULTS
Mean arterial pressure (MAP) and blood glucose are linearly related to mortality (P<0.0001). Regression analysis shows that each has an independent effect. Moreover, the relationship between blood glucose and mortality is stronger than the relationship between MAP and mortality. When patients are grouped according to lowest MAP, hyperglycaemia is associated with increasing mortality within each group (P<0.0001).


CONCLUSIONS
Further studies on the combined effect of hyperglycaemia and hypotension on mortality after head injury are needed because this study suggests, but does not prove, an additive, causal association.
Walia
Sandeep
S
Department of Anaesthesia and Intensive Care, Selly Oak Hospital, Birmingham B29 6JD, UK.
Sutcliffe
Anne J
AJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure; D006259:Craniocerebral Trauma / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D006801:Humans; D006943:Hyperglycemia / Q000150:complications*; D007022:Hypotension / Q000150:complications*; D016015:Logistic Models; D008875:Middle Aged; D015996:Survival Rate
D001786:Blood Glucose