Intra-Abdominal Pressure, Respiratory Mechanics, and Ventilator Liberation After Emergency Major Laparotomy

Prior treatment

• Elective abdominal surgery.
• Abdominal surgery completed laparoscopically without an open laparotomy.
• Open abdomen or temporary abdominal closure at the end of surgery.
• Planned second-look laparotomy or planned surgical reintervention within the first 48 hours.
• Bladder injury, previous bladder surgery, neurogenic bladder, or other urinary tract conditions that may compromise the reliability of intravesical pressure measurements.

Other illness

• Bronchopleural fistula, significant endotracheal tube or ventilator circuit leakage, or other mechanical problems preventing reliable measurement of plateau pressure and static respiratory system compliance.
• Advanced neuromuscular disease, high-level spinal cord injury, or known diaphragmatic paralysis directly affecting ventilator liberation.

Age

• Age younger than 18 years.

Other

• Laparotomy performed for traumatic injury.
• Absence of invasive mechanical ventilation at postoperative ICU admission.
• Contraindication to urinary catheterization or inability to obtain reliable intra-abdominal pressure measurements through the urinary catheter.
• Extracorporeal membrane oxygenation (ECMO) support.
• Pre-existing dependence on chronic invasive mechanical ventilation.
• Pregnancy.
• A decision for exclusively palliative care or limitation of life-sustaining treatment at ICU admission.
• Refusal to participate by the patient or legally authorized representative, or inability to obtain written informed consent.
• Inability to obtain simultaneous baseline intra-abdominal pressure and respiratory mechanics measurements at ICU admission.

• Age 18 years or older.
• Undergoing non-traumatic emergency major abdominal surgery performed through an open laparotomy.
• Direct admission to the intensive care unit following surgery.
• Receiving invasive mechanical ventilation through an endotracheal tube or tracheostomy at the time of postoperative ICU admission.
• Primary abdominal fascial closure performed at the end of surgery.
• Presence of an indwelling urinary catheter allowing intra-abdominal pressure measurement using the intravesical technique.
• Availability of simultaneous intra-abdominal pressure and respiratory mechanics measurements at the initial assessment after ICU admission.
• Written informed consent obtained from the patient or, when the patient lacks decision-making capacity, from a legally authorized representative or an eligible relative in accordance with applicable regulations and ethics committee requirements.
• Additional written consent obtained from the patient for continued participation if decision-making capacity is regained during the study.