Absence of a tachycardic response to shock in penetrating intraperitoneal injury

The belief that tachycardia is an early and reliable indicator of shock has recently been challenged. We examined 144 battlefield casualties with penetrating intraperitoneal injury to determine whether patients in shock presented with pulse rates that were significantly more rapid than those in patients not in shock. No differences in mean pulse rates were found when using objective operational definitions of shock. In contrast, the only pulse rate difference was noted when shock was defined on the basis of the surgeon's subjective clinical impression and this was attributed to selection bias. The absence of a tachycardic response in battlefield casualties with penetrating abdominal wounds cannot be taken as an indication that serious injury and significant intraperitoneal bleeding have not occurred. Caution should be exercised when using this parameter as a guide for therapeutic interventions, and further study is indicated to determine whether a similar pattern is seen in civilian practice.