EFFECT OF HYPERTONIC SALINE SOLUTION AND DEXTRAN ON VENTRICULAR BLOOD-FLOW AND HEART-LUNG INTERACTION AFTER HEMORRHAGIC-SHOCK

Background. Hypertonic saline solutions may have beneficial hemodynami c effects in, the resuscitation of hemorrhagic shock. The effects on c ardiac function and potential interaction with lung function are contr oversial and served as the basis for this study. Methods. Domestic swi ne were resuscitated from hemorrhagic shock with equivalent sodium loa ds of lactated Ringer's solution (LR) or 7.5% NaCl plus 10% dextran (H SD). Hemodynamic data were obtained at baseline, shock, and after resu scitation. Right ventricular ejection fraction and left ventricular ch ange in pressure with respect to time (dP/dt) were used to index contr actility. Regional myocardial blood flow was determined with microsphe res. Lung water was determined gravimetrically. Results. There were no differences in the ability to restore hemodynamic parameters with equ ivalent sodium lends of LR and HSD resuscitation. Right ventricular ej ection fr action and left ventricular change in pressure with respect to time were only transiently affected by shock and resuscitation. Reg ional myocardial blood flow was increased above baseline values after NSD. The total resuscitation volumes were 1958 +/- 750 mL and 140 +/- 31 mL with LR and HSD, respectively. Conclusions. Although LR and HSD were equally effective in the early resuscitation of hemorrhagic shock , this occurred at the expense of significantly greater volume require ments for resuscitation with LR. This may contribute to cardiac dysfun ction in this setting. Enhanced regional myocardial blood flow after H SD resuscitation may be beneficial against ongoing myocardial stress.