Outcomes Research in Anesthesiology

In the modern practice of Anesthesiology, we strive to make clinical decisions based on evidence. Outcomes research is the discipline that focuses on providing this evidence. In short, it tells us what does work, and what does not work.

Typically, outcomes research focuses on an intervention or treatment, and whether it advances patient care. An example would be a study that seeks to determine if using a special type of laryngoscope makes intubating patients in the operating room easier. That study would involve using two different types of laryngoscopes and measuring successful attempts at intubation. Successful intubation would be the outcome in question.

Some of the common types of outcomes studies are cross-sectional studies, meta-analyses, and randomized controlled trials. Cross-sectional studies are a snapshot in time of a large population. They look at the characteristics of given groups to make inferences about outcomes without manipulating variables. A meta-analysis combines the results of multiple studies to find an “average” or “true” outcome of multiple studies. A randomized controlled trial reduces bias in a study by randomly allocating subjects to two groups, a control group without intervention, and an experimental group receiving the intervention in question. Of the three study types mentioned, randomized controlled trials provide the strongest evidence.

In anesthesiology, there are a set of core outcomes that the field evaluates. The Anesthesiology Quality Institute (AQI), a division of The American Society of Anesthesiology, set up a series of “core outcomes” on which anesthesiologists focus [2]. They are chosen because they dramatically impact patients’ lives. These outcomes include things like death, cardiovascular complications, and procedural complications. 

Anesthesiologists are keenly interested in outcomes research as it relates to their patients in the operating room and the intensive care unit. Some of the interesting topics being explored are monitored anesthesia care vs. general anesthesia, use of video laryngoscopy vs. direct laryngoscopy, and the effect of opioid and inhalational anesthesia on cancer risk.

A good demonstration of typical outcomes research in anesthesiology is Park et al.’s paper entitled “Comparison between monitored anesthesia care and general anesthesia in patients undergoing device closure of atrial septal defect [3].” They measured number and severity of lung complications as well as turnover time pertaining to the two types of anesthesia. The study found that patients in the monitored anesthesia care group and the general anesthesia group had an equal number of pulmonary complications. It also found that patients in the monitored anesthesia care group had a faster turnover time. These two outcomes are important to an anesthesiologist and demonstrate the value of outcomes research in the field.

A second excellent example of outcomes research in anesthesiology comes from Griesdale et al. in their study “Video-laryngoscopy versus direct laryngoscopy in critically ill patients: a pilot randomized trial [4].” In their randomized controlled trial, patients were placed in either a video laryngoscopy group or a direct laryngoscopy group. For their outcomes, Griesdale’s team measured successful glottic visualization and level of oxygen desaturation. The initial outcome of the study showed improved glottic visualization in the video laryngoscopy group. This implies there must be some superiority to the video laryngoscopy, but the video laryngoscopy’s oxygen saturation was 86% compared to the direct laryngoscopy group’s 95%. This second outcome, though unexpected, shows the benefits of taking more than one outcome into account.

While it may be intimidating to engage with the material of outcomes research, its results are essential for improving anesthetic care. The above studies show that familiarizing ourselves with its methods and results will help us make better choices for our patients.

Works Cited

1.            Jefford, M., M.R. Stockler, and M.H. Tattersall, Outcomes research: what is it and why does it matter? Intern Med J, 2003. 33(3): p. 110-8.

2.            Whitlock, E.L., J.R. Feiner, and L.L. Chen, Perioperative Mortality, 2010 to 2014: A Retrospective Cohort Study Using the National Anesthesia Clinical Outcomes Registry. Anesthesiology, 2015. 123(6): p. 1312-21.

3.            Park, Y.S., et al., Comparison between monitored anesthesia care and general anesthesia in patients undergoing device closure of atrial septal defect. J Thorac Dis, 2019. 11(4): p. 1421-1427.

4.            Griesdale, D.E., et al., Video-laryngoscopy versus direct laryngoscopy in critically ill patients: a pilot randomized trial. Can J Anaesth, 2012. 59(11): p. 1032-9.