A necessary component of anesthesia drug regimens is the inclusion of a drug to induce muscle relaxation, which reduces or eliminates a patient’s ability to breathe without a ventilator. Postventilation reversal of the muscle relaxation has primarily been done by administration of the drug neostigmine. However, researchers found that 5% of adult patients undergoing noncardiac inpatient surgery experience a major pulmonary complication post surgery and believe that this results from the muscle relaxants’ residual effects. 

New research indicates that there may be an alternative intervention that can lower the incidence of such adverse outcomes. Published in April in Anesthesiology, the authors hypothesize that the choice of neuromuscular blockade reversal may be associated with a lower incidence of major pulmonary complications. 

Lead author Sachin Kheterpal, MD, MBA, professor of anesthesiology at the University of Michigan Medical School, and his team explored whether the choice of reversal for neuromuscular blockade translates to a lower risk of serious lung complications in patients undergoing noncardiac inpatient surgery.

Five percent of adult patients undergoing elective noncardiac inpatient surgery experience a major pulmonary complication. The authors hypothesized that the choice of neuromuscular blockade reversal, sugammadex versus neostigmine, may be associated with a lower incidence of major pulmonary complications.

The primary outcome was the occurrence of major pulmonary complications experienced postsurgically, including pneumonia, respiratory failure, or other pulmonary complications such as pulmonary congestion, pulmonary embolism, infarction, or pneumothorax. The researchers examined 45,712 patients who were administered general anesthesia and intubated, receiving neuromuscular blockade of either vecuronium or rocuronium with reversal by the older standard agent, neostigmine, or the newer agent, sugammadex. 

Using a multicenter observational matched-cohort design, the researchers evaluated the surgical cases of 22,856 patients who received sugammadex and an equal number of patients who received neostigmine, matched by sex, age, comorbid diagnoses, type of surgical procedure and institution where the surgery was performed. 

The authors reported that 45,712 patients 1,892 (4.1%) experienced major pulmonary complications, with 4.8% for neostigmine versus 3.5% for sugammadex. After multivariable analysis, the authors  found that compared with neostigmine, sugammadex was associated with a 55% reduced risk of respiratory failure (adjusted [OR] 0.45; 95% CI 0.37-0.56), 47% reduced risk of pneumonia (adjusted OR 0.53; 95% CI, 0.44-0.62), and 30% reduced risk of pulmonary complications (adjusted OR 0.70; 95% CI, 0.63-0.77). 

Dr. Kheterpal noted, “For example, pneumonia may be related to the inability to take a deep breath or cough due to residual muscle weakness,” adding "When we looked at documentation of respiratory failure or pneumonia, we saw a 37% decrease across all pulmonary complications and 55 percent decrease in respiratory failure. This is a dramatic decrease in rates of complications.” 

The authors concluded that in patients undergoing inpatient surgery within hospitals in the United States, the use of sugammadex was associated with a clinically and statistically significant lower incidence of major pulmonary complications. However, they acknowledged the study limitations: it was not a randomized, and did not include emergency surgeries, which would have expanded the generalizability of the findings.

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