Evaluation of the effect of different PEEP applications on optic nerve diameter during laparoscopic surgery in hypertensive patients

Background and purpose Pneumoperitoneum created in laparoscopic surgeries causes many changes in the respiratory system and metabolic system. Positive end-expiratory pressure (PEEP) is one of the methods used to minimize these changes and can cause an additional increase in intracranial pressure (ICP) by compressing cerebrospinal flow outflow and cerebral venous drainage during pneumoperitoneum.Increased ICP is more pronounced in patients with uncontrolled hypertension.Measuring noninvasive optic nerve sheath diameter (ONSD) by ultrasonography; It is one of the methods used in the follow-up of the IDD during the surgery.In this study, we aimed to evaluate the effect of different PEEP applications on optic nerve diameter in hypertensive patients undergoing laparoscopic surgical cholecystectomy. Materials and Methods Forty patients with controlled hypertension between the ages of 18 and 75 years in the ASA 2-3 group who will undergo laparoscopic cholecystectomy in the reverse Trendelenburg position were included in our study.After anesthesia induction, the patients were divided into PEEP 5 group and PEEP 8 group by the closed envelope method.Patients' gender, age, weight, body mass index (BMI), American Society of Anesthesiologists Physical Status Classifications (ASA class), operations performed, hemodynamic data during the case (systolic-diastolic-mean arterial pressures, pulse, saturation) and ONSDs are determined. recorded at intervals. On the patients' ONSD measurement, after anesthesia induction, with the eyes closed with the linear ultrasound probe over the eyelid horizontally on the 5th minute (OSD1), pneumoperitoneum at the 5th minute (OSE2), pneumoperitoneum at the 30th minute (OSE3), surgical completion (OSW4), every made from two eyes and averaged.Optic nerve sheath diameter over 5.5 mm was considered significant.IBM SPSS Statistics 20 version was used for statistical analysis, p <0.05 values were considered statistically significant. Results:. 20 patients in PEEP 5 groups, 20 patients in PEEP 8 groups completed the study.In total, 24 women (60%) and 16 men (40) participated and there was no statistically significant difference between the two groups.The mean age of PEEP 5 group was 64.4, and the mean age of PEEP 8 group was 53.2, and there was a statistically significant difference (p 0.017).There was no difference in other demographic (BMI, comorbidity, ASA) and hemodynamic data between the groups.No difference was observed between the two groups at all times when the optic nerve sheath diameters of the patients were measured.When we compared the ONSDs within the group, it was found that the optic nerve diameter in both groups showed a statistically significant change during the operation course. Discussion and Conclusion The effects of PEEP 5 and PEEP 8 administration on optic nerve diameter in patients with controlled hypertension are similar.We believe that physiological (minimum) PEEP application and moderate PEEP application in this patient group can be used safely since it does not change the ONSD, which is the indirect indicator of IDB.More comprehensive studies are needed for high-level PEEP implementation.