The comparison of volume and pressure controlled ventilation in laparoscopic cholecystectomy

Laparoscopic cholecystectomy has been adopted as the golden standart for the treatment of cholelithiasis and gall bladder diseases since the laparoscopy has began to be used for surgery. CO2 pneumoperitonium method is used to expose the surgical field and enough surgical view. The laparoscopic cholecystectomy has some systemic disadvantages by caused of elevated intraabdominal pressure, position, and general anaesthesia eventhough has lot of advantages (the short lenght of hospital stay, minimally postoperative pain, rapidly recovery). In this study, the effects on hemodynamic respiratory and blood gas parameters were compared by applying VCV and PCV in laparoscopic cholecystectomy anaesthesia. This study was performed using randomization method after approved by the ethic commitee of Akdeniz University Medical School Hospital. After informed consent, 70 volunteer ASA 1-2 physical status patients who were diagnosed cholelithiasis by surgeons and scheduled for elective laparoscopic cholecystectomy were included in this study in all patients, premedication was applied by ıv midazolam 0.01 mg/kg at thirty minutes before the operation. Cardiac rate by EKG, SpO2, OAP by brachial noninvasive blood pressure, EtCO2, BİS, TOF monitorization were performed. The patients ages, body heights, BMİ, and medical history was recorded on preoperative period. In all patients, general anaesthesia was induced with iv propofol 2-3 mg/kg, iv fentanyl 1-2 mcg/kg, iv rokuronyum 0,5-0,6 mg/kg, anaesthesia was maintained with a iv propofol infusion 4-8 mg/kg/hour and mixture of nitrous oxide (50%) and oxygen (50%) analgesia was maintained with iv fentanyl 1-2 mcg/kg fluid resusciation was supplied with 0,9% Nacl 5-7 ml/kg/hour. Reverse trendelenburg position was given to patients after placing trocars (30 degree head up and 30 degree left side). The patients were divided into two groups randomly according to the applied mechanical ventilator mode: group 1 (35 patients) pressure controlled ventilation, group 2 (35 patients) volume controlled ventilation Patient?s hemodynamic datas and respiratory parameters, arterial blood gases were measured, the patient?s allertness were evaluated and recorded by measuring eye tearing and pupil diameter. Dynamic compliance, oxygenation index, alveolar ? arterial oxygen gradient, dead space tidal volume ratio were calculated. There was no difference between the groups in demographic datas (age, height, weight) and operation, and anaesthesia, pneumoperitoneum and wake up times (p >0,05) table 3.1. BIS and heart rate were significantly higher in group 1 than group 2 after removal of the gall bladder. Respiratory frequency was higher in group 2 at 20 minutes after insufflation and at removal of the gall bladder (p<0,05). Ph values was significantly higher in group 2 after intubation and at 10 minutes after insufflation when the groups were compared. The dead space ventilation tidal volume ratio at the measurements before pneumoperitoneum and alveolar ?arterial oxygen gradient at the measurements after pneumoperitoneum were significantly higher than in group 1 (p<0,05). Dynamic complians were similar in two group. In summary, in this study, it was found that tidal volume was higher and alveolar arterial oxygen gradient was lower in volume controlled ventilation applications after pneumoperitoneum. These findings indicate that volume controlled ventilation is able to provide better alveolar ventilation than pressure controlled ventilation in laparoscopic choleycystectomy surgery.