Hemodynamic patterns preceding circulatory deterioration and death after trauma

To describe the sequence of hemodynamic changes associated with sudden circulatory deterioration compared with those of terminal patients to identify the earliest signs warning of shock and death.

This is a prospective observational study of 89 patients with thermodilution cardiac index and continuous noninvasive hemodynamic monitoring who had episodes of circulatory deterioration. These data were compared with the data of a second group of 24 patients in their terminal stage just before death.

The earliest indications of impending collapse were decreased cardiac index, and tissue perfusion reflected by decreased transcutaneous O2 tension (PtcO2). This was followed by reduced blood pressure, tachycardia, reduced arterial hemoglobin saturation, and increased transcutaneous CO2 tension (PtcCO2). This pattern of changes was more pronounced in the nonsurvivors and was seen in exaggerated form in terminal patients.

Sequential hemodynamic patterns revealed reduced blood flow and poor tissue perfusion as the earliest warning signs in both circulatory deterioration and death. These were followed by reduced mean arterial pressure, tachycardia, and low values of pulse oximetry. Adequate blood flow and even distribution of flow are needed for tissue perfusion.