FiO2 Closed Loop Control Ventilation

Completed

Interventions: Device: Closed Loop Control Ventilation
Device: Manual Control Ventilation

Brief Summary: 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.

Detailed Description: 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.

Recruitment & Eligibility

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

Arm && Interventions

Group	Intervention	Description
Closed Loop Control Ventilation	Closed Loop Control Ventilation	automatic adjustment of the ZOLL 731 ventilator FiO2 by the closed loop control software
Manual Control Ventilation	Manual Control Ventilation	manual adjustment of the ZOLL 731 ventilator FiO2 by the treatment team based on physician order

Primary Outcome Measures

Name	Time	Method
Relative Duration With Oxygen Saturation (SpO2) Within Target Range [Time Frame: 12 Hours]	12 hours	Relative duration is (time within SpO2 target of 92-96%)/12 hours where higher value demonstrates better ability of FiO2 control method to maintain appropriate oxygen saturation. Relative time the patient's SpO2 was maintained within target over the 12 hours on the study device, calculated as total time each patient had SpO2 within the 92 - 96% range divided by 12 hours with arcsin square root transformation
Number of Participants With SpO2 Less Than 88% at Anytime While on Study Device	24 hours after intervention	Number of participants with SpO2 less than 88% at anytime while on study device

Secondary Outcome Measures

Name	Time	Method
Relative Duration of Time With SpO2 92 to 96% When FiO2 is Greater Than 21% and SpO2 is Greater Than or Equal to 92% When Fi02 "Relative Duration With Oxygen Saturation (SpO2) Within Target Range [Time Frame: 12 Hours]	12 hours	Relative duration is (time within SpO2 target of either a) 92-96% when FiO2 is greater than 21% or b) greater than or equal to 92% when FiO2 equals 21%)/12 hours where higher value demonstrates better ability of FiO2 control method to maintain appropriate oxygen saturation. Relative time the patient's SpO2 was maintained within target over the 12 hours on the study device, calculated as total time each patient had SpO2 within the range divided by 12 hours with arcsin square root transformation