Hemodynamic patterns in trauma patients

Introduction

The main cause of shock in trauma patients is hypovolemia secondary to blood loss; other causes are cardiac tamponade, tension pneumothorax, myocardial contusion and neurogenic shock. However, there are several patients who remain in shock after adequate fluid resuscitation and without other causes of shock.

Objective

To identify the hemodynamic pattern of patients with trauma and shock, after hemorrhagic control and correct fluid administration.

Materials and methods

We included consecutive patients admitted to a trauma ICU, from 1 January 2003 to 31 December 2004, who had hemorrhagic control of the trauma lesions and were treated with fluid and remained dependent on vasoactive drugs.

Results

Eighty-five patients, or 6.2% of the patients admitted during the recruitment, met the criteria. The mortality was 59%, against 34% (P < 0.01) of the population without the criteria. The main cause of death was refractory shock. The mean crystalloid used in the first 24 hours was 9015 ml (± 3202 ml), the mean hydroxyethyl starch was 1463 ml (± 1868 ml), the mean red cell pack administration was 3 U (± 3.43 U) and the mean fresh frozen plasma was 2 U (± 2.82 U). Twenty-five patients (30%) were submitted to invasive monitoring with a pulmonary arterial catheter. The mean PAOP was 16 mmHg (± 5.67 mmHg) but six patients had a PAOP below 12 mmHg; the mean CI was 5.3 l/m² (± 2.3 l/m²) but five patients had CI <3.0 l/m²; and the mean SVRI was 1132 dyn/m²/s (± 508 dyn/m²/s).

Conclusion

The presence of shock was associated with high mortality. The most prevalent hemodynamic pattern was hyperdynamic shock; but 25% (six patients) had hypovolemia even after vigorous fluid resuscitation, and 12.5% (three patients) had hypodynamic shock. The invasive monitoring of the pulmonary artery was important to diagnose the class of shock and to identify the presence of residual hypovolemia.