Comparison of the Effects of Different Positive Expiratory Pressure Levels on Patient Oxygenation and Mechanical Power Values in Laparoscopic Surgeries

Perioperative pulmonary complications and ventilator-associated lung injury are challenging issues for anesthesiologists, especially after laparoscopic surgeries. An increasing number of studies suggest lung protective ventilation (LPV) strategies in these patients. It is recommended that patients&; driving pressure be kept low during LPV and positive expiratory pressure (PEEP) be applied to keep the lungs open. However, high PEEP values cannot be adequately applied in laparoscopic surgeries to reduce the restrictive peak pressure for LPV. In laparoscopic surgeries, the patients position and increased intra-abdominal pressure create pressure on the lungs. However, when the applied positive pressure ventilation is insufficient in patients, it can cause atelectasis, and when it is excessive, it can cause barotrauma or volutrauma. The threshold values determined for all these possible complications during LPV should be evaluated together.

Gattinoni and colleagues (2016) explained the effect of mechanical ventilation on the lungs through a work/time formula and formulated the energy used during this work. The applied energy is spent on opening the lungs and ventilation, while the excess is consumed due to heat and resistance in the respiratory tract. The unit of this energy can be formulated in a simplified way as joule/second. The mechanical power formula makes it easier to follow by providing a single parameter instead of different threshold values for barotrauma, volutrauma and atelectrauma for the lungs. Studies have shown that applying energy over 12.6 joules is associated with lung damage. On the other hand, the relationship between the optimum mechanical power (MP) value during ventilation and low and high PEEP is not yet fully known.

In laparoscopic surgeries, high PEEP application may help keep the lungs open and increase ventilation, but it may cause higher mechanical power application. In this case, the effect of high PEEP application on ventilation and patient outcomes is unclear.

In this study, PEEP values and mechanical power values applied during ventilation in patients who will be operated under laparoscopic surgery will be monitored observationally and the PEEP/MP relationship will be examined in terms of patient oxygenation.