Intraoperative Oxygen Practices in Cardiac Surgery: A National Survey

Abstract

Objective: To describe the current nationwide perspectives and practice regarding intraoperative oxygen titration in cardiac surgery.

Design: Prospective, observational survey.

Setting: Hospitals across the United States.

Participants: Cardiovascular anesthesiologists and perfusionists.

Interventions: Expert- and consensus-derived electronic surveys were sent to perfusionists and cardiac anesthesiologists to evaluate the current intraoperative practices around oxygen administration. Providers were asked about individual intraoperative oxygen titration practices used at different stages of cardiac surgical procedures. Anonymous responses were collected in the Research Electronic Data Capture (REDCap).

Measurements and main results: A total of 3,335 providers were invited to participate, of whom 554 (317 anesthesiologists and 237 perfusionists) were included in the final analysis (17% response rate). During cardiopulmonary bypass (CPB), perfusionists reported a median (interquartile range [IQR]) target range from 150 (110-220)-to-325 mmHg (250-400), while anesthesiologists reported a significantly lower target range from 90 (70-150)-to-250 mmHg (158-400) (p values <0.0001 and 0.02, respectively). This difference was most pronounced at lower partial pressure of arterial oxygen (PaO₂) ranges. The median PaO₂ considered "too low" by perfusionists was 100 mmHg (IQR 80-125), whereas it was 60 mmHg (IQR 60-75) for anesthesiologists, who reported for both off and on bypass. The median PaO₂ considered "too high" was 375 mmHg (IQR 300-400) for perfusionists and 300 mmHg (IQR 200-400) for anesthesiologists. Anesthesiologists, therefore, reported more comfort with significantly lower PaO₂ values (p < 0.0001), and considered a higher PaO₂ value less desirable compared with perfusionists (p < 0.0001).

Conclusions: This survey demonstrated there was wide variation in oxygen administration practices between perfusionists and anesthesiologists. Hyperoxygenation was more common while on CPB.

Keywords: cardiac anesthesia; cardiac surgery; cardiopulmonary bypass; hyperoxia; oxygen; perfusion.

Fig 1.

Assembly of the study cohort. Of the 2,306 anesthesiologists from the Society of Cardiovascular Anesthesiologists membership distribution list and 1,029 American Society of ExtraCorporeal Technology members invited to participate, 554 responded indicating their role, allowing them to be included in the analysis. The overall response rate was 17%; however, this was higher in perfusionists compared with anesthesiologists (23% vs 14%).

Fig 2.

Titration of partial pressure of arterial oxygen (PaO₂) while on bypass. Perfusionists reported a median (interquartile range) target range from 150 (110–220)-to-325 (250–400) while on bypass. Anesthesiologists reported a significantly lower target range on bypass from 90 (70–150)-to-250 (158–400) while on bypass (p values <0.0001 and 0.02, respectively). This difference was most pronounced at lower PaO₂ target ranges. In the figure, medians and interquartile ranges are represented by the blue dots and error bars. Individual respondent values for what should be considered the minimum or maximum value on bypass are presented in black for perfusionists and red for anesthesiologists.

Fig 3.

Intraoperative oxygen titration by perfusionists and anesthesiologists. This figure represents the results from asking both perfusionists and anesthesiologists whether they would increase, maintain, or decrease the level of administered oxygen at varying partial pressure of arterial oxygen (PaO₂) thresholds. Anesthesiologists were asked similar questions with varying thresholds of peripheral arterial oxygen saturation (SpO₂) values. In the figure, anesthesiologists are represented in red and perfusionists in gray. Overall, anesthesiologists tended to report more comfort with lower PaO₂ values and considered higher PaO₂ values more injurious compared with perfusionists.