THE EFFECT OF SECONDARY INSULTS ON MORTALITY AND LONG-TERM DISABILITY AFTER SEVERE HEAD-INJURY IN A RURAL REGION WITHOUT A TRAUMA SYSTEM

Outcome after head injury appears to be adversely affected by secondary insults such as hypoxia or hypotension. Previous work examining the influence of these secondary insults on outcome has originated from urban environments with organized systems of trauma care. We hypothesized that secondary insults would be more frequent and that outcome of severe head injury would be worse in a rural region without a trauma system. To validate these hypotheses we retrospectively reviewed the course and outcome of all patients admitted to the Medical Center Hospital of Vermont with severe head injuries between 1980 and 1985. A cohort of 170 patients was assigned to one of two groups: group I had neither hypotension nor hypoxia at the time of admission; group II had either hypotension or hypoxia at the time of admission. The groups were similar in terms of demographics, incidence of mass lesions, frequency of craniotomy, and incidence of intracranial hypertension. Only 23% of group II patients made a good recovery compared with 56% of group I patients (p < 0.01). The mortality rate of group II patients was twice that of group I patients (66% vs. 33%; p < 0.01). When compared with data provided by the National Trauma Coma Data Bank from urban areas with trauma systems, there was no difference in outcome of patients similarly grouped according to the presence or absence of secondary insults between Vermont's rural cohort and the urban cohort. We conclude that hypotension and hypoxia adversely effect the outcome of severe head injury. The data also suggest that the impact of these secondary insults may occur early such that conventional therapies available in an organized system of care are ineffectual in reversing them.