Nitroprusside in resuscitation of major torso trauma

Patients with thoracic aortic injury (TAI) usually have sustained other major trauma, and may require aggressive shock resuscitation. In the 24 hours after aortic repair and during resuscitation, our cardiothoracic surgeons request intravenous nitroprusside to maintain mean arterial pressure (MAP) less than 90 mm Hg to minimize bleeding at the repair. We compared the resuscitation response of patients who sustained major torso trauma (MTT) and TAI with that of patients who had MTT with no TAI to determine whether nitroprusside can effectively control MAP during resuscitation and whether use of nitroprusside, because of its peripheral vasodilatory effects, is associated with a favorable resuscitation response.

During the 9-month study period, 11 patients who sustained TAI and 38 patients who sustained MTT with no TAI met multiple organ failure risk/shock criteria and were resuscitated by a standardized protocol emphasizing volume loading and hemoglobin replacement to maintain systemic oxygen delivery index (DO2I) > or = 600 mL O2/min-m2 for the first 24 intensive care unit hours. For TAI patients, postoperative management included intravenous nitroprusside infusion titrated by the bedside nurse to maintain mean arterial pressure (MAP) less than 90 mm Hg during the same 24 hours. Data were obtained prospectively during resuscitation. Retrospectively, the resuscitation response of TAI and non-TAI patients was compared.

For the TAI group, nitroprusside effectively controlled MAP (range, 77-87 mm Hg); for the non-TAI group, mean MAP exceeded 95 mm Hg within 5 hours. During the first 8 hours, MAP, pulmonary capillary wedge pressure, and systemic vascular resistance index were less, and DO2I was greater for the TAI than for the non-TAI group. The resuscitation goal of DO2I > or = 600 mL O2/ min-m2 was attained at 4 hours for the TAI group, and was attained at 12 hours for the non-TAI group. No revisions of aortic repairs were required during or as a result of resuscitation.

During aggressive shock resuscitation, control of MAP using nitroprusside is feasible and is associated with a favorable resuscitation response. Nitroprusside may be a useful adjunct during shock resuscitation of MTT as a vasoactive agent that promotes peripheral tissue perfusion.