One in 500 surgery patients sustains upper airway injury
MedWire News: About one in every 500 patients undergoing major surgery sustains an upper airway injury, shows an analysis of over a million patients.
Airway injury is thought to be relatively common during surgery, but May Hua (Columbia University Medical Center, New York, USA) and colleagues say that previous studies are limited to case reports and series.
The team therefore analyzed data on 563,190 patients from the American College of Surgeons National Quality Improvement Program (NSQIP) database. The patients underwent major surgical procedures between 2005 and 2008.
In all, about one in every 500 patients had an airway injury during surgery, Hua et al report in the journal Anesthesia & Analgesia.
Specifically, 0.2% of the patients had airway injury, with by far the most common type of injury being lip laceration/hematoma, accounting for 61.4% of injuries. Tooth injury was the next most common injury, at 26.1% of all injuries, followed by tongue laceration at 5.7%, pharyngeal laceration at 4.7%, and laryngeal laceration at 2.1%.
On multivariate analysis, patients aged 80 years or older were 50% more likely to have upper airway injury than those aged 40-49 years. But the researchers say that a true relationship with age is unlikely, given the "modest level of association" and the overall absence of a dose-response relationship.
The only other significant independent predictor of airway injury was Mallampati class. Patients in Mallampati classes III and IV had significant 1.69-fold and 2.47-fold increases in airway injury risk, respectively, compared with those in classes I and II. The researchers note that this association "parallels the relationship of Mallampati class with difficult intubation."
They add: "One might assume that there is a relationship between Mallampati class and airway injury because difficult intubation causes injury. However, because larger amounts of oropharyngeal soft tissue may make intubation more difficult and airway injury more likely, the Mallampati classification may independently be associated with both outcomes."
Neither gender nor body mass index, American Society of Anesthesiologists class, and surgical specialty were associated with the risk for airway injury.
"Participation in the NSQIP is voluntary and thus the study sample is unlikely to be representative of all surgical patients," cautions the team. "As a result, it might be unwise to extrapolate the findings of this study into other study populations and geographical regions."
By Eleanor McDermid