Pentoxifylline restores the depressed cardiac performance after trauma-hemorrhage and resuscitation

Although studies have shown that pentoxifylline (PTX) improves tissue perfusion and hepatocellular function after trauma-hemorrhage and resuscitation, it is not known whether this agent has any beneficial effects on left ventricular performance under such conditions. To study this, rats underwent laparotomy (i.e., trauma induced) and were bled to and maintained at a blood pressure of 40 mm Hg until 40% of the maximum shed blood volume was returned in the form of Ringer's lactate. The animals were then resuscitated with four times the volume of shed blood with Ringer's lactate over 60 min, following which PTX (50 mg/kg body wt) or an equivalent volume of normal saline was infused intravenously over 100 min. Maximum dP/dt during contraction (+dP/dtmax) and relaxation (-dP/dtmax), maximum rate of a "pressure-normalized" change in ventricular pressure during ventricular contraction (dP/dtmax/P), and ventricular peak systemic pressure (VPSP) were determined at 15 min before the completion of resuscitation and every 30 min up to 4 hr after resuscitation. The results indicated that both +dP/dtmax and -dP/dtmax decreased significantly beginning at 0.5 h after resuscitation and remained depressed throughout the study period in saline-treated animals. In addition, VPSP was significantly depressed at 2.5 to 4 hr after resuscitation. Treatment with PTX, however, significantly improved the above parameters as well as dP/dtmax/P and heart rate. Since PTX restores various left ventricular performance parameters, this agent appears to be a useful adjunct for improving cardiac function after trauma and hemorrhagic shock, even in the absence of blood resuscitation.