A Comparison of the Effects of Lung Protective Ventilation and Conventional Ventilation on Thermoregulation During Anaesthesia.

Objective: During prolonged surgery, hypothermia is an unwanted condition that frequently develops and increases complication rates. It has been shown that positive end-expiratory pressure (PEEP) during mechanical ventilation reduces hypothermia development by providing earlier peripheral vasoconstriction. In the present study, an investigation was made of the effect of two different ventilation models on perioperative hypothermia development.

Methods: A total of 40 patients undergoing elective lumbar disc surgery were randomised to either the conventional group (Group C, n=20, tidal volume=10 mL kg, PEEP=0 cm HO) or the lung protective ventilation group (Group P, n=20, tidal volume=6 mL kg, PEEP=5 cm HO). Demographic data on gender, age, weight, height, preoperative-postoperative temperatures and haemodynamic values were recorded. The point where the forearm to fingertip skin temperature difference reached 0°C was determined as the peripheral vasoconstriction development. At this point, the core temperature was recorded as the thermoregulatory vasoconstriction threshold.

Results: Demographic characteristics of the patients and haemodynamic variables were similar between the groups. Preoperative and postoperative temperature gradients were not significantly different between the two groups (p=0.827). There was also no significant difference between the two groups in respect of the vasoconstriction threshold of the patients (p=0.432).

Conclusion: The study results showed that lung protective ventilation has no advantage in preserving the perioperative core temperature compared to conventional ventilation.