Effect of Pressure-controlled inverse ratio ventilation during laryngeal mask airway anesthesia on ventilatory parameters

Abstract

The majority of patients undergoing ocular surgery have underlying cardiovascular diseases due to old age, and because gastric emptying is one of the complications seen in recovery. Inverse ratio pressure during general anesthesia with laryngeal mask airway on ventilation parameters. Materials and Methods: In this randomized clinical trial study, patients undergoing cataract surgery were selected as the sampling source. All patients were included in the study in terms of inclusion and exclusion criteria and also after obtaining informed consent and were divided into two groups and examined. Patients were divided into two groups: normal ventilation (PCV) and reverse ventilation (PCIRV) and were examined. Eighty patients were studied. In the compression ventilation group with normal ratio (I/E 1:2), the maximum airway pressure was adjusted so that the current volume of 6 ml / kg was delivered to the patient's lungs based on the ideal body weight and after starting the number of breaths with 8-10 per minute, then the number of breaths was changed to maintain EtCo2 between 30 and 35 mmHg as needed. In the group, compression ventilation with inverse ratio was exactly the same as the previous group, but the ratio of inhalation to exhalation was 1.5:1 (I/E 1.5:1) Results: Peak pressure values were significantly lower in the PCIRV group compared to the PCV group at 1, 5 and 20 minutes after anesthesia. The results also showed that in the PCIRV group the values of airway dynamic compliance at times 1, 5 and 10 minutes after anesthesia were significantly lower than the PCV group. Tidal volume values in the PCIRV group were significantly lower at 1, 5 and 10 minutes after anesthesia. Also, ETCO2 values in this group were relatively low compared to PCV group, but no statistically significant difference was observed. Both groups had adequate oxygenation. In the present study, the number of pain cases in the PCIRV group was significantly lower than the PCV group in terms of pain after recovery in the studied patients (7.5% vs. 17.5%; p=0.023).