Although many anesthesiologists do not routinely reverse neuromuscular blockade at the end of surgery, a study has found that patients who are left to spontaneously recover from such blockade are six times as likely to need reintubation within 48 hours of surgery as their counterparts who received a reversal agent. Of the modifiable risk factors evaluated in the model, the failure to use a reversal agent appeared to have the strongest influence on early risk for reintubation.
“Every institution experiences unplanned tracheal intubations in the early postoperative period, which are rare but potentially catastrophic events. At the time of tracheal extubation, full recovery of muscle strength should be present, and the residual effects of intraoperative anesthetic agents resolved,” said Glenn S. Murphy, MD, clinical professor of anesthesiology at the NorthShore University Health System, in Chicago, and the University of Chicago’s Pritzker School of Medicine. “Obviously, there are patient factors that come into play, but how we manage patients in the operating room may also contribute to the risk of a patient being reintubated.”
The risks associated with unplanned reintubation have been well documented, and include increased postoperative morbidity and mortality. A 2012 analysis (BMJ 2012;345:e6329) found that reintubation requiring admission to the ICU was associated with a 90-fold higher risk for in-hospital mortality. “Those findings suggest [that] strategies to optimize respiratory muscle strength prior to extubation may reduce mortality,” Dr. Murphy said.
To determine the factors associated with the need for reintubation after surgery, the investigators reviewed the Premier hospital database, which contains information on all hospital visits to any Premier system hospital, to identify patients who underwent general or vascular surgery and were discharged between Jan. 1, 2012 and Dec. 31, 2013. Reintubations occurring at any time during the hospital stay were identified, and potentially related risk factors were examined. Multivariate models were then developed to assess adjusted risks for reintubation based on those factors.
As reported at the 2015 annual meeting of the International Anesthesia Research Society (abstract S-304), the study found that 7,152 of 557,592 patients analyzed were reintubated (1.3%). Of these, 2,343 (0.42%) occurred within 48 hours of surgery. “It’s possible that anesthetic management factors may have played a contributing role in reintubations that occur within 48 hours of surgery,” Dr. Murphy said in an interview with Anesthesiology News.
The multivariate analysis found that the strongest associations with reintubation at any time after surgery were trauma versus elective surgery (relative risk [RR], 6.04; 95% confidence interval [CI], 4.22-8.66), a diagnosis of sepsis (RR, 7.70; 95% CI, 7.23-8.20), pneumonia (RR, 3.78; 95% CI, 3.54-4.05), hemiplegia (RR, 3.25; 95% CI, 2.80-3.78) and the use of a neuromuscular blocking agent without a reversal agent (RR, 3.96; 95% CI, 3.68-4.25).
When the researchers focused their analysis on the first 48 hours after surgery, they found that the RR for reintubation was greatest among patients undergoing trauma surgery (10.51; 95% CI, 6.61-16.73), followed by those who received a neuromuscular blocking agent without reversal (RR, 6.02; 95% CI, 5.35-6.78). The RR for reintubation on postoperative day 3 was greatest among patients with sepsis (12.32; 95% CI, 11.26-13.48) and pneumonia (4.26; 95% CI, 3.88-4.68).
“I think these data support the idea that neuromuscular blockade should be routinely reversed in patients who receive nondepolarizing muscle relaxants,” Dr. Murphy said. “I think that’s been the opinion of many experts in the field for a long time. Even so, a large percentage of anesthesiologists do not routinely reverse.
“Recovery times from most nondepolarizing neuromuscular blocking agents can be extremely variable and affected by a number of factors,” he added, “so we can’t really identify who the outliers are going to be. Because of that—unless you have quantitative monitoring —I think that we’re obligated to reverse patients. In fact, I think the only time you shouldn’t reverse neuromuscular blockade is if you have a quantitative monitor, like a TOF [train of four]-Watch, that tells you that muscle function has fully recovered.”