Intraoperative Mechanical Power and Ventilation-Associated Lung Injury: Assessing Complications

Postoperative pulmonary complications (PPCs) are often underestimated yet remain a leading cause of perioperative morbidity and mortality. These complications encompass postoperative hypoxia, atelectasis, bronchospasm, pulmonary infections, infiltrations, aspiration pneumonia, acute respiratory distress syndrome (ARDS), pleural effusion, and pulmonary edema. They are prevalent and associated with significant costs, prolonging hospital stays, ventilation duration, and ICU admissions, while also increasing mortality and morbidity risks.

Perioperative mechanical ventilation stands as a primary risk factor for the development of postoperative pulmonary complications. Approximately one in four patients with normal lungs will develop some form of lung injury following mechanical ventilation, although much of this damage can be mitigated through the use of appropriate ventilation strategies. A range of pulmonary complications induced by mechanical ventilation is known as ventilator-induced lung injury (VILI).

A growing understanding of the injury mechanism aids researchers in identifying risk factors for lung injury, including tidal volume, respiratory rate, pressures, and flow. Mechanical power, which combines tidal volume, respiratory rate, and airway pressure, has been identified as a potential contributor to VILI. The greater the power, the higher the likelihood of lung injury occurring.

Mechanical power represents the total energy expended over a specific period and is typically expressed in joules per minute (J/min). The equation for mechanical power can help estimate the contribution of different causes of VILI and their variations. This equation can be easily applied in the software of each ventilator. Recent studies have investigated threshold values for mechanical power in relation to ventilator-associated lung injury using the simplified formula found for mechanical power

Inclusion criteria

• Patients aged 18 years and older
• Patients undergoing elective major abdominal surgery
• Patients with ASA (American Society of Anesthesiologists) physical status classification I-IV
• Patients capable of providing voluntary consent

Exclusion criteria

• Patients under 18 years of age
• Pregnant individuals
• Those who decline to participate in the study
• Patients requiring reoperation due to surgical complications
• Organ transplant recipients
• Patients who were intubated preoperatively
• Day surgery patients