Hematocrit, systolic blood pressure and heart rate are not accurate predictors for surgery to control hemorrhage in injured patients

Hematocrit (Hct), systolic blood pressure (SBP), and heart rate (HR) are considered to closely correlate with hypovolemia in injured patients. The clinical importance of these parameters in the early recognition of occult but clinically significant hemorrhage remains to be demonstrated. We undertook this study to assess the clinical importance of these parameters in the early recognition of occult hemorrhage in injured patients. A retrospective study of 7880 patients admitted to a Level I trauma center was carried out. Patients who underwent surgery were divided into the hemorrhage (n = 160) and no-hemorrhage group (n = 228). Hematocrit, SBP, and HR were correlated and receiver operating characteristic (ROC) curves were plotted. The ROC curves for Hct, SBP, and HR showed suboptimal areas under the graph. Even for different Hct thresholds and for hypotension and tachycardia, low predictive values were found. Although Hct, SBP, and HR levels were significantly altered among patients who require surgery for hemorrhage, the low predictive values of each parameter renders them as clinically unreliable individual tools for recognition of hemorrhagic patients who need surgery. Although useful in aggregate, as a pattern, or as indications for further diagnostic studies, these common parameters have limited usefulness individually.