Armaghane Danesh Bimonthly Journal (Jul 2007)
The Effect of Low Flow Inhalation Anesthesia on Operative Hemodynamic Condition in Comparison with High Flow Anesthesia
Abstract
Introduction & Objective: Low flow anesthesia technique in which the flow fresh gas is lower than minute volume of the patient results in improvement in the patient’s care such as reduction of operative hypothermia, reduction of postoperative shivering and leads to an increase in economical and enviornmental interests. The goal of the study was to investigate the patients’ operative hemodynamic variations using the high and low flow anesthesia techniques. Materials & Methods: This prospective, clincal and single blind study was carried out in Tbriz Emam Khomeini Hospital in 1384. In this study 97 patients in ASA class I or II after routine induction of G.A, during maintenance of anesthesia were randomly divided in two groups group I (high flow anesthesia) and group II (low flow anesthesia). For all patients ECG, HR, SPO2, BP, B.T, ETCO2 and inspiratory, expiratory percentage of O2, N2O, halothane, postoprative shievring and duration of oprations were recorded. 46 patients underwent high flow anesthesia and 51 patients underwent low flow anesthesia. Results: The average blood pressure in group I was as follow: preoperative, systol=13820 mmHg and diastol=7815 mmHg, intraoperative, systol=10531 mmHg and diastol=6410 mmHg and in recovery systol=11615 mmHg and diastol=7013 mmHg. In group II who had low flow anesthesia the blood pressure was found to be systol=13922 mmHg and diastol=7922 mmHg preoperative, systol=12221 mmHg and diastol=7517 mmHg intraoperative and systol=11815 mmHg and diastol=7717 mmHg in recovery. The differences in blood pressure in both group were statiscally significant (p=0.01). The average heart rate in group I was 9018 beat/min preoperative, 7014 intraoperative and 126 in recovery. The avrage heart rate in group II was 87.921 preoperative, 8616 intraoperative and 10417 in recovery. The differences were statiscally significant but there was no significant difference between the two groups with regard to sex, age and weight. Conclusion: Maintenance of anesthesia with low flow anesthesia gasses maintains more hemodynamic condition during operation.