Cardiac compliance and effects of hypertonic saline

To demonstrate the advantages of a 1.8% hypertonic saline solution (HS) over a Ringer's lactate solution (RL) during and after major intra-abdominal surgery, 28 patients were randomly allocated to one of two groups as follows: 13 patients received RL and 15 patients received HS. All patients were studied preoperatively, peroperatively and postoperatively for 72 hours. Peroperatively RL or HS were infused at a rate sufficient to maintain a pulmonary capillary wedge pressure (PCWP) and central venous pressure (CVP) within 3 mm Hg of the initial value. The left ventricular end-diastolic volume index (LVEDVI) was calculated from determination of stroke index and ejection fraction with a mobile gamma camera. Biopsy specimens were taken from the rectus abdominis muscle for evaluation of edema. The two groups of patients were comparable for age, length of surgery and length of aortic cross-clamping. Preoperatively natremia, serum osmolarity, PCWP and LVEDVI were similar in both groups. A significant (p = 0.01) difference was noted, during and after surgery, between the sodium levels in the two groups, but the levels remained within normal limits. Serum osmolarity remained similar for the two groups (p = 0.49). During and after surgery, PCWP (p = 0.1) and CVP (p = 0.7) remained within 3 mm Hg of the initial values with no significant difference between the two groups. The HS group received significantly (p = 0.002) less liquid than the RL group. At the end of surgery, the LVEDVI dropped in both groups. This drop was significantly (p = 0.04) more important in the RL group than in the HS group.(ABSTRACT TRUNCATED AT 250 WORDS)