Characteristics of patients receiving vasopressors

Patients receiving intensive care frequently need pharmacologic support of their blood pressure because of shock. In some patients, shock is so severe that extremely high doses of vasopressors are needed to elevate their blood pressure.

We sought to ascertain the maximal dose of vasopressors administered to patients, and to describe the population of patients receiving vasopressors in one intensive care unit.

All adult patients admitted in 2001 to a 10-bed surgical unit in a university hospital, and receiving a vasopressor agent for 1 hour or more, underwent recordings of their demographic data, diagnoses upon admission, Acute Physiological and Chronic Health Evaluation (APACHE) II scores, vasopressors (including type, initial dose, dose increases, and maximal dose), number of days administered, complications, and mortality.

Of 689 patients whose charts were reviewed, 72 received vasopressors. The mean age was 65 ± 21.4 years, and 66% were male. The mean APACHE II scores were 24 ± 6.2. The administration of .5 μg/kg/minute of norepinephrine or epinephrine resulted in 96% sensitivity and a specificity of 76% for the likelihood of mortality. Using Kaplan-Meyer curves, those patients receiving less than .5 μg/kg/minute demonstrated an 80% 6-year survival. All 17 patients receiving more than 3.8 μg/kg/minute of norepinephrine, and all 5 patients receiving more than 9.6 μg/kg/minute of epinephrine, died. The length of time during which patients received less than their maximal dose of vasopressors had no influence on survival (P = .4). The elderly (aged ≥ 75 years) and the young (aged <75 years) had the same intensive care unit survival rates when receiving vasopressors.

In this study, little likelihood of intensive care unit survival was evident when patients received more than .5 μg/kg/minute of norepinephrine or epinephrine.