Safety of Optimal PEEP in NSICU Patients

Evaluating Safety of Transpulmonary Pressure Guided PEEP Management in Neurocritical Care Patients

The investigators aim to demonstrate that use of transpulmonary pressure to guide PEEP management is safe in patients with possible elevations of intracranial pressure.

Purpose: To establish safety of titrating PEEP based on transpulmonary pressure as measured by an esophageal balloon in mechanically ventilated neurosurgical patients.

Participants: Adult patients admitted to the Neuro ICU at UNC Hospital and requiring mechanical ventilation who have an intracranial pressure monitoring device in place.

Procedures (methods): All enrolled patients will have esophageal balloons placed with measurement of transpulmonary pressures. All patients will have baseline measurements recorded of intracranial pressure, cerebral perfusion pressure, and cerebral autoregulation. PEEP will then be titrated based on transpulmonary pressure measurements with recording of physiological measurements over the next hour. At the conclusion of the hour, all patients will be returned to their prior ventilator settings.

Inclusion Criteria:

• Adult patients (age >/= 18) admitted to the Neuro ICU of UNC Hospital requiring mechanical ventilation and with ICP monitoring in place.

Exclusion Criteria:

1. Pneumothorax or pneumomediastinum
2. Life expectancy < 24 hours or expected to require mechanical ventilation for < 24 hours
3. Condition that precludes placement of an esophageal balloon [esophageal or nasopharyngeal pathology preventing insertion of the esophageal balloon catheter (esophageal ulcerations, tumors, diverticulitis, bleeding varices or in patients with sinusitis, epistaxis or recent nasopharyngeal surgery), severe thrombocytopenia (platelet count < 30) or coagulopathy (INR > 3 or on oral anticoagulants).
4. Pre-enrollment ICP > 20 mm Hg
5. Pre-enrollment CPP < 60 mm Hg
6. Planned change in the external ventricular drain set point during the pre-intervention, intervention or post-intervention periods
7. Incarceration
8. Variation in ICP of > 2 cm H2O in the hour prior to intervention.