Despite the apparent risks, using a neuromuscular blocking agent (NMBA) before tracheal intubation improves the odds of first-attempt intubation success in critically ill ICU patients, a study has found.
“The question of whether to paralyze or not to paralyze is clearly answered in the operating room and emergency department: Using a paralytic is the way to go if you want to increase your first-attempt success at intubation,” said Jarrod M. Mosier, MD, an assistant professor of medicine and emergency medicine at the University of Arizona, Tucson. “However, we don’t know if this is true in the ICU as well.
“We also know that ICU patients are very different from those in the other two arenas. They’re sicker, and often times the people intubating them are not as experienced as in the other two venues when it comes to tracheal intubation.”
To help get a handle on the potential risks and rewards associated with intubating ICU patients, Dr. Mosier and his colleagues enrolled 664 consecutive patients into the observational study. Intubation-related data were collected prospectively on all patients intubated in the ICU over the study period, and then analyzed. The researchers also performed a propensity adjustment for factors predetermined to affect the decision to use an NMBA. Adjusted multivariate regression analysis was used to evaluate the effect of neuromuscular blockade on first-attempt success.
Although the two groups were found to be demographically similar, those who did not receive neuromuscular blockade had a greater number of median difficult airway predictors (DAPs) than their counterparts (2.4 vs. 1.8;P<0.001). Significant differences also were found between groups with respect to the sedative used and the operator’s level of training. Indeed, more paralyzed patients were sedated with etomidate (83% vs. 35%; P<0.0001), whereas more patients in the non-NMBA group received ketamine (39% vs. 9%; P<0.001). The researchers reported their findings at the 44th Critical Care Congress of the Society of Critical Care Medicine (abstract 729).
Dr. Mosier noted that first-attempt intubation success was greater among patients who were first paralyzed than those who were not (81% vs. 70%;P=0.003). After controlling for total DAPs, device used, sedative and operator level of training, the propensity-adjusted odds ratio for first-attempt success with neuromuscular blockade was 2.17 (95% confidence interval [CI], 1.29-3.66; P<0.001). There were no differences in procedure-related complications between groups.
These findings proved surprising to the researchers, particularly in an age where video laryngoscopy has gained such a strong foothold. “I thought that with the advent of video laryngoscopy, you probably wouldn’t need a paralytic,” he explained. “Personally, I was only paralyzing about half of my patients because why would you need a paralytic to improve your view if the view is provided by the camera?”
The investigators also looked into a subgroup of patients intubated via video laryngoscopy, and found that the propensity-adjusted odds ratio of first-attempt success with the use of neuromuscular blockade was 2.50 (95% CI, 1.43-4.37; P<0.001).
Administering neuromuscular blockade to ICU patients is not without its risks, however, which makes patient selection and provider technique all the more important. “If you can’t get an airway, you’ve taken away somebody’s spontaneous breathing,” Dr. Mosier said. “If you can’t intubate, that’s a situation that could quickly spiral out of control.
“With that in mind, I would recommend that if you’re in the ICU with a critically ill patient who needs to be intubated and you think that you can mask ventilate them in the event of a failure, then a neuromuscular blocker will increase your odds of first-attempt success.”