There was no difference between reverse Trendelenburg position (RTP) and beach chair (BC) position during laparoscopic sleeve gastrectomies (LSG) in terms of haemodynamic and respiratory parameters however, inspiratory and peak pressures (resistance) were lower and dynamic compliance was higher in the BC position, according to a study by researchers from Istınye University Medicalpark Gaziosmanpasa Hospital, Istanbul, Turkey.
Following a literature review, the investigators could not identify any studies investigating the combination of 30° RTP and BC positions in LSG. This study hypothesised that 30° RTP combined with the BC position could improve the patient’s cardiopulmonary functions and would not affect the surgical field of view. Patients in the study, were randomised into two groups:
Group RTP: 30° reverse Trendelenburg (control)
Group BC: 30° reverse Trendelenburg with legs 30° hip flexion (beach chair position)
The study was conducted under the same general surgeon and no patient required position change during the operation. All patients were routinely extubated and taken to the postoperative recovery room, and blood pressure, pulse, and SpO2 were recorded at the 10th and 20th minutes postoperatively.
Outcomes
Regardless of the group, the average age of the cases was 36.7±12.1 years. The groups were similar in terms of age, gender, BMI and operation time. There was no statistically significant difference between systolic, diastolic blood pressures and heart rates between the groups (p>0.05), but a significant decrease in blood pressure and a non-significant slight increase in heart rate were observed in the first 10 min after RTP in both groups.
In comparing the groups in terms of respiratory parameters, there was no difference between EtCO2, respiratory rate, PEEP, minute volume, tidal volume, and postoperative oxygen saturation (p>0.05, Table 2). However, when we looked at the changes over time, it was determined that EtCO2 decreased at the 10th minute in both groups compared to preoperative values. Tidal volume increased significantly at the 10th minute compared to preoperative values only in the BC position. Additionally, postoperative oxygen saturations in both groups were lower than preoperative values, but after the abdomen was deflated (70th minute), oxygen saturation increased significantly in both groups (p<0.05).
In comparing pressures from respiratory parameters, a statistically significant difference was detected between the groups in terms of inspiratory pressure (Pins), peak pressure (PPeak) and dynamic compliance throughout the operation period. According to their findings, pressures such as Pins and Ppeak were lower in the BC position, and dynamic compliance was significantly higher (p<0.05).
The 10th minute after positioning was the time interval in which Pins and Ppeak decreased the most and dynamic compliance increased the most, according to preoperative values in both groups (p<0.05). There was no difference in these parameters between the 70th minute when pneumoperitoneum was terminated and the previous 60th minute.
The researchers grouped BMI to understand how BMI affects these pressures (BMI groups 30–35, 35.1–40 and 40.1 and above) they found the BC position decreased the inspiratory and peak pressures, and increased the dynamic complication in patients with BMI: 35.1—40 (p<0.05).
However, when the effect of BMI differences within the groups on pressures was examined, no significant difference was detected.
“It was observed that these parameters were related to BMI and that the BC position was more ameliorative in terms of intraoperative pressures and dynamic compliance, especially in patients with a BMI between 35.1 and 40. In light of our findings, we believe that the BC position may be preferred in terms of lung-protective ventilation strategies.”
The findings were reported in the paper, ‘The effect of two different surgical positions on pulmonary functions in laparoscopic sleeve gastrectomies: reverse Trendelenburg vs beach chair’, published in Surgical Endoscopy. To access this paper, please click here
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