Transient systolic hypotension. A serious problem in the management of head injury
R. J. Winchell, R. K. Simons and D. B. Hoyt
Department of Surgery, University of California, San Diego, USA.
OBJECTIVE: To determine the frequency and clinical impact of transient
systolic hypotension (systolic blood pressure < 100 mm Hg) in patients
with severe anatomic head injury. DESIGN: Retrospective case-control study.
SETTING: Urban level 1 trauma center. PATIENTS: Consecutive trauma patients
admitted to the intensive care unit (ICU) with severe anatomic head injury,
defined as Head and Neck Abbreviated Injury Scale Score of 4 or higher. One
thousand thirteen trauma patients were admitted to the ICU during the study
period, 157 of whom met inclusion criteria. MAIN OUTCOME MEASURES: Acute
mortality, defined as death during initial ICU admission, and functional
status of ICU survivors, assessed as level of function sufficient for
discharge to home. RESULTS: One hundred fifty-seven patients with severe
head injury had a total of 831 episodes of systolic hypotension. Fifty-five
percent of the patients suffered at least one event. Patients were grouped
by total number of low systolic blood pressure events and by average number
of events per ICU day. The total number of hypotensive events was
associated with increased mortality rates and decreased rate of discharge
to home. Average daily frequency of events was associated with increased
mortality rates. After stratification by admission Glasgow Coma Scale
score, the effects were most dramatic in patients with an initial Glasgow
Coma Scale score higher than 8. CONCLUSIONS: Transient hypotension is
common in the ICU and is associated with increased acute mortality and
decreased functional status in patients with head injury. The impact of
this secondary insult is greatest in patients with less severe primary
injury. Strict avoidance of hypotension through enhanced monitoring and
active treatment appears to be important, especially in patients with
higher presenting Glasgow Coma Scale scores.