FiO2 Closed Loop Control Ventilation

FiO2 Closed Loop Control Using the ZOLL 731 Series Ventilator

A randomized, multi-center trial involving critically-ill patients comparing conventional, manual control of inspired oxygen (FiO2) within a target range, with a computer-controlled, closed-loop FiO2 delivery using a continuous ventilator.

The trial will use a proportional-integral-derivative (PID) type controller for automatic adjustment of FiO2 to maintain the SpO2 within a target range, based on continuous use of pulse oximetry. Intubated subjects will be randomized to either manual control of FiO2 or closed-loop control of FiO2, during a 12-hour period. The PCLC is designed to respond to acute hypoxemia (SpO2 <88%) within seconds while preventing hypoxemia and minimizing exposure to excessive inspired oxygen levels.

Inclusion Criteria:

• The subject's legally authorized representative will provide signed and dated informed consent.
• Age 18 - 65, inclusive.
• Admission to a surgical or neurosurgical intensive care unit following traumatic injury or acute surgical illness
• Requirement for endotracheal intubation
• Requirement for mechanical ventilation
• Patient is currently receiving inspired oxygen concentration (FiO2) >=40%

Exclusion Criteria:

• Age under 18 or over 65
• Isolated or severe head injury (Glasgow Coma Scale = 6 or less) with expected survival less than 24 hours
• Brain death
• Anticipated survival less than 48 hours
• Pregnant female
• Patient in whom a pulse oximeter cannot detect a reliable signal due to hypotension, hypothermia, or other injury
• Known carbon monoxide poisoning
• Uncontrolled diabetic
• Patient who is unable to maintain SpO2 level of 88% at an FiO2 of 100% due to their medical condition. (NOTE: Being in the trial would impose no additional risk to a patient who presents with this condition however, data from a patient presenting with this pathophysiology would not provide insight into the performance of the controller as it would simply maintain that patient on an FiO2 of 100%.)
• Patient with chronic hypercarbia.
• Patient where a physician believes that FiO2 PCLC could be detrimental to the management of the patient.
• Prisoner
• SpO2 to SaO2 difference >4%
• Patient with core temperature <35 C