Intraarterial pulmonary pentoxifylline improves cardiac performance and oxygen utilization after hemorrhagic shock: a novel resuscitation strategy.

Abstract

The role of pentoxifylline (PTX) as a resuscitation adjunct in hemorrhagic shock is unclear. PTX infusion into the pulmonary artery and its effects on cardiac performance and oxygen utilization have not been defined. We hypothesized that pulmonary PTX is superior to systemic PTX or lactated Ringer's (LR) solution alone. The effects of LR solution, systemic PTX, and pulmonary PTX on cardiac performance and oxygen utilization in a hemorrhagic shock model in dogs were compared. Animals were bled to a mean arterial blood pressure (MAP) of 40 mm Hg maintained for 30 min and randomized into 3 resuscitation groups: LR solution (2x shed blood), systemic PTX (10 mg/kg bolus i.v.) in addition to LR solution (2x shed blood) + PTX (5 mg/kg for 45 min i.v.), and pulmonary PTX (10 mg/kg bolus + 5 mg/kg for 45 min via a pulmonary artery catheter) plus LR solution (2x shed blood, i.v.). Arterial blood gases, hemoglobin levels, MAP, cardiac index, systemic vascular resistance index, pulmonary vascular resistance index, oxygen delivery, oxygen consumption, and oxygen extraction ratio (O(2)ER) were measured serially. No differences in blood loss, hemoglobin, and MAP were observed. Pulmonary PTX increased cardiac index to levels more than baseline (P = 0.012) and decreased systemic vascular resistance index and pulmonary vascular resistance index to levels less than baseline (P < 0.0001). Pulmonary PTX increased oxygen delivery and oxygen consumption to baseline levels. Postresuscitation O(2)ER levels in LR-treated animals remained more than baseline (P < 0.0001). Systemic and pulmonary PTX significantly decreased O(2)ER compared with shock levels. PTX resuscitation is superior compared with LR solution alone. Intraarterial pulmonary PTX administration is safe, and improves cardiac performance as well as O(2) utilization. This study shows that a novel route (via the pulmonary circulation) used to administer pentoxifylline after hemorrhagic shock leads to superior cardiac performance in comparison with administration via lactated Ringer's solution or i.v. systemic pentoxifylline.