Subjects
This study was carried out in accordance with the Declaration of Helsinki and approved by the Ethics Committee of the Harran University (Approval Number 2019.4.20). After the approval of the hospital ethics committee, The study was registered in the Australian New Zealand Clinical Trials Registry (ANZCTR) (Trial Id: ACTRN12620000169943). Patients who underwent elective laparoscopic cholecystectomy under general anesthesia for cholelithiasis between November 2019 and February 2019 were included in this cross sectional study. Written informed consent was obtained from all patients. Patients over the age of 18 years with written consent and with an American Anesthesiologists Association (ASA) physical score I or II were included in the study. Exclusion criteria; Pregnancy, acute lung disease, heart failure, body mass index (BMI) below 18 and above 40, intraoperative bleeding over 100 ml, intraoperative inotropic support requirement, pneumoperitoneum duration over 45 min and under 20 min. All patients were fasted for at least 8 hours before surgery, and none of the patients received premedication.
Anesthesia management and hemodynamic monitoringBefore general anesthesia induction, standard anesthetic monitoring was performed with electrocardiography (ECG), peripheral O2 saturation (SpO2), non-invasive arterial pressure (NIBP) monitoring. The MightySat ™ Rx Fingertip Pulse Oximeter (Masimo Corporation, Irvine, CA) probe was attached preventing it from being affected by light to the upper extremity index finger tip, where the blood pressure cuff is not attached. Anesthesia induction was performed by the same anesthetist with fentanyl (2 μg / kg) and propofol (2-3 mg / kg). Rocuronium bromide 0.6 mg / kg was used as a muscle relaxant. Volume controlled ventilation was applied to the patients after intubation. Ventilator settings were made as follows: tidal volume was 8 ml / kg according to ideal body weight, positive end-tidal pressure (PEEP) was 5 cmH2O, inspirium expirium ratio was 1: 2, respiratory rate was 11-14 breaths / minute and then the end-tidal carbon dioxide pressure (EtCO2) was adjusted to be 35-45 mmHg. Sevoflurane and iv remifentanil (0.25-0.5 μg / kg / min) infusion was used in the mixture of air and oxygen for maintenance of anesthesia.
Study design Data were collected after anesthesia induction in all patients. In order to minimize the effect of vasomotor tone, any stimulation to the patients was avoided up to 5 minutes before the data was collected. PVI and SpHg data were recorded by the same anesthesiologist in 6 pre-determined times in the end-expiratory phase. T0 = ​​basal value after insufflation T1 = 5th minute of insufflation T2: 10th minute of insufflation T3: 15th minute of insufflation T4 = 5 minutes before desufflation T5 = 2 minutes after desufflation Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), oxygen saturation (SpO2), EtCO2 values ​​were recorded in the same time frames. In addition, body mass index, operation duration and pneumoperitoneum duration of the patients were recorded. 8 ml / kg crystalloid solution was given to patients before anesthesia induction in order to prevent sudden blood pressure decrease that may develop in patients as a result of anesthesia induction, thus minimizing the impact of PVI and SpHb values. Crystalloid infusion continued at the rate of 4 ml / kg / h throughout the operation.