Splanchnic perfusion during controlled hypotension combined with acute hypervolemic hemodilution: a comparison with combination of acute normovolemic hemodilution-gastric intramucosal pH study.

摘要

STUDY OBJECTIVE: To evaluate the effect of controlled hypotension combined with acute hypervolemic or normovolemic hemodilution on the splanchnic perfusion in the clinical setting. DESIGN: Randomized, prospective study. SETTING: Inpatient surgery at Nagasaki Rosai Hospital. PATIENTS: 28 ASA physical status I and II patients scheduled for total hip arthroplasty.Interventions: Patients were randomly divided into two groups. Group A (n = 14) received controlled hypotension with acute normovolemic hemodilution (ANH). Group B (n = 14) received controlled hypotension with acute hypervolemic hemodilution (HHD). ANH was produced by drawing approximately 1000 mL of blood and replacing it with the same amount of 6% hydroxyethyl starch solution (HES). HHD was produced by preoperative infusion of 1000 mL of 6% HES without removing blood. The final hematocrit values were 24+/-2% (mean +/- SD) in Group A and 25+/-3% in Group B. Controlled hypotension was induced with prostaglandin E1 (PGE1) to maintain mean arterial blood pressure at 55 mmHg for 80 minutes. MEASUREMENTS: Measurements included the gastric pH (pHi), the arterial blood pH (pHa), and plasma lactate. These indices were measured before hemodilution, after hemodilution, 80 minutes after starting hypotension, 60 minutes after recovery from hypotension, and on the first postoperative day. The value of pHi was measured by tonometric method. MAIN RESULTS: The pHa and lactate values showed no change in either group A or group B throughout the time course. Gastric pHi values in group A showed a significant decrease from 7.424+/-0.033 to 7.335+/-0.038 (p<0.05) after hemodilution, whereas it showed no further decrease at 80 minutes after starting hypotension and 60 minutes after recovery from hypotension. The pHi values in group B showed no significant decrease after hemodilution and no further change at 80 minutes after starting hypotension. CONCLUSIONS: HHD does not impair splanchnic perfusion, whereas ANH might cause impairment. Controlled hypotension with prostaglandin E1 would not impair splanchnic perfusion in combination with either HHD or ANH.