Evaluation of the Risk of Hyperoxia-induced Hypercapnia in Obese Cardiac Surgery Patients

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

30 participants

Study Classification

INTERVENTIONAL

Study Start Date

2016-09-30

Study Completion Date

2018-01-08

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

This study aims to evaluate the risk of hyperoxia-induced hypercapnia in post-op obese cardiac surgery patients. It will compare two oxygenation modes in terms of their effect on the arterial partial pressure of carbon dioxide (PaCO2) : manual titration of oxygen delivery for a peripheral oxygen saturation (SpO2) target of \> or = 95 % versus automatic titration by a closed-loop system for a SpO2 target of 90%. 15 post-op obese cardiac surgery patients will be recruited and each will receive both interventions (cross-over design). The main outcome will be the PaCO2, which will be compared after each study period. The research hypothesis is that the usual SpO2 target of \> or = 95 % is associated with a greater PaCO2 compared with a lesser SpO2 target of 90%.

Related Clinical Trials

Explore similar clinical trials based on study characteristics and research focus.

Automatic Oxygen Administration After Major Abdominal and Thoracic Surgery

NCT02546830

Major Thoracic and Abdominal Surgery

COMPLETED NA

Intraoperative Oxygen Concentration and Neurocognition After Cardiac Surgery

NCT02591589

Hyperoxia Normoxic Delirium

UNKNOWN NA

Feasibility of End-tidal Oxygen Concentration Monitoring During Preoxygenation for Intubation in the Intensive Care Unit.

NCT05409573

Critically Ill

RECRUITING NA

The Effect of Hypercapnia on Physiological Parameters During Short-term Breathing

NCT05441007

Hypoxia Hypercapnia Cardiac Output, High

UNKNOWN NA

Comparison of Pulse Oximetry (SpO2) With Different Oximeters and Arterial Saturation (SaO2): Oxygap2 Study

NCT06102499

Respiratory Failure Hypoxemia Hyperoxemia

RECRUITING

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

This study aims to evaluate the risk of hyperoxia-induced hypercapnia in post-op obese cardiac surgery patients.

The investigators will compare two oxygenation modes in terms of their effect on PaCO2 : a SpO2 target of \> or = 95 % achieved with manual titration (usual practice) and a more conservative SpO2 target of 90 % achieved with automatic titration by a closed-loop system (FreeO2).

The choice of a SpO2 target of 90 % is consistent with recent guidelines issued by the British Thoracic Society and the Thoracic Society of Australia and New Zealand, which both recommend a SpO2 target of 88-92 % for morbidly obese patients (BMI \> 40 kg/m2).

FreeO2 is a closed-loop oxygen delivery system which adjusts the oxygen flow according to the patient's real-time SpO2 and a target programed by the physician. The system also records data on heart rate, respiratory rate and SpO2. Its safety and efficacy have been tested in healthy subjects as well as in patients suffering from COPD or acute respiratory distress in the emergency room, with promising results.

The research hypothesis is that the usual SpO2 target of \> or = 95 % is associated with a greater PaCO2 compared with a lesser SpO2 target of 90%.

30 obese patients will be recruited\* at the Institut universitaire de cardiologie et de pneumologie de Québec. A written consent from the patient will be obtained the day before the surgery. The protocol has been submitted to and approved by the establishment's ethics committee.

The study will compare the effect of two different oxygenation modes on the patients' PaCO2 immediately after extubation :

FreeO2 mode : oxygen delivered by nasal cannula or Venturi mask (if flow \> 5L/min during \> 5 minutes), automatically titrated for a SpO2 of 90 +/- 2 %

Usual mode : oxygen delivered by Venturi mask, manually titrated for a SpO2 superior or equal to 95 % (the local protocol is to deliver a post-extubation FiO2 which is 10 % superior to the pre-extubation FiO2)

Patients meeting all of the eligibility criteria will be randomized in the postoperative period. After extubation, they will receive oxygen for 30 minutes according to FreeO2 mode or the usual mode, depending on randomization. After 30 minutes, a first arterial blood gas will be obtained through their arterial cannula. Next, they will be oxygenated according to the second oxygenation mode for another 30 minutes, after which a second arterial blood gas will be obtained. Each patient will thus act as his own control (cross-over design).

When patients will be oxygenated according to the usual mode, FreeO2 will be in recording mode, but will not be delivering any oxygen.

The study will last 1h for each patient, and will have to begin within 30 minutes after extubation. A member of the research team will be at the patient's bedside for the whole data collecting period.

Complete data collection should be achieved within 12 months.

Demographic data (age, sex, weight, height and BMI) will be collected upon study entering as well as pre-operative room air PCO2 on capillary blood gas, type of surgery (number of bypass grafts, extracorporal circulation time), opiates dosage per-op and post-op, and pre-op left ventricular ejection fraction and renal function. FreeO2 will be recording respiratory rate, heart rate and SpO2 for the whole study duration. The respiratory rate will also be recorded manually and on the monitor. When patients will be receiving oxygen from FreeO2, the system will record the delivered flow ; with the usual mode, the staff will record the delivered FiO2. At the end of each intervention, hemodynamic measures will be taken : systolic, diastolic and median arterial blood pressure, systolic, diastolic and median pulmonary artery pressure and amine level.

\*Initially, 15 patients were supposed to be included. After inclusion of those 15 patients, statistical analyses showed a lack of statistical power and a possibly significant difference in PaCO2, but only in half the patients. We thus submitted a protocol amendment to our institution's ethics committee to enlarge the sample size to 30 patients, which was accepted on July 13th, 2017.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Obesity Hyperoxia Hypercapnia

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

RANDOMIZED

Intervention Model

CROSSOVER

Primary Study Purpose

SUPPORTIVE_CARE

Blinding Strategy

NONE

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

Group A

15 patients who will receive usual care for 30 minutes and then switch to FreeO2 for another 30 minutes

Group Type ACTIVE_COMPARATOR

FreeO2

Intervention Type OTHER

Oxygen delivery automatically titrated by a closed-loop system that adjusts the oxygen flow based on the patient's real-time SpO2 and a programed SpO2 target of 90 %

Usual care

Intervention Type OTHER

Oxygen delivery manually titrated by the nursing staff for a SpO2 target of \> or = 95 %

Group B

15 patients who will be oxygenated by FreeO2 for 30 minutes and then switch to usual care for another 30 minutes

Group Type ACTIVE_COMPARATOR

FreeO2

Intervention Type OTHER

Oxygen delivery automatically titrated by a closed-loop system that adjusts the oxygen flow based on the patient's real-time SpO2 and a programed SpO2 target of 90 %

Usual care

Intervention Type OTHER

Oxygen delivery manually titrated by the nursing staff for a SpO2 target of \> or = 95 %

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

FreeO2

Oxygen delivery automatically titrated by a closed-loop system that adjusts the oxygen flow based on the patient's real-time SpO2 and a programed SpO2 target of 90 %

Intervention Type OTHER

Usual care

Oxygen delivery manually titrated by the nursing staff for a SpO2 target of \> or = 95 %

Intervention Type OTHER

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

* BMI \> 30 kg/m2
* SpO2 \> or = 95 % before extubation
* Procedure : coronary artery bypass

Exclusion Criteria

* Comorbidities : chronic obstructive pulmonary disease, cystic fibrosis, restrictive syndrome not associated with obesity (pulmonary fibrosis, neuromuscular junction disease, etc.)
* Obstructive sleep apnea requiring a positive-pressure mask in the posteoperative period
* FreeO2 device unavailable
* Inclusion in another study that does not permit dual inclusion

Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No