Closed Claims Airway Injury Analysis Spotlights Problems

Although 15 years have passed since the last airway injury analysis of the American Society for Anesthesiologists (ASA) Closed Claims Project, new research reveals that pharyngeal and esophageal perforations continue to be a significant source of patient morbidity and mortality—as well as liability for anesthesiologists. The investigators noted, however, that practitioner diligence is key to reducing the severity of these sometimes-fatal injuries.

“In 1999, Domino et al published a review of airway injuries [Anesthesiology 1999;91(6):1703-1711] in the Anesthesia Closed Claims Project database and found that 8.5% of general claims had airway injuries as the outcome,” reported Karen L. Posner, PhD, the Laura Cheney Professor in Anesthesia Patient Safety at the University of Washington, in Seattle. “The most common injuries in that analysis were pharyngeal and esophageal perforations, at 23%. That was quite a while ago, however, so we thought we’d look at airway injuries again, as well as trends over time.”

To that end, Dr. Posner and her colleagues analyzed the database of 10,093 malpractice claims that were focused on airway or esophageal injuries associated with general anesthesia between 1980 and 2011. The researchers classified the site of airway injury and used claim narratives to identify perforations of the pharynx or esophagus. An on-site closed claims reviewer identified difficult intubations. Claims for airway injuries that occurred between 2000 and 2011 (N=116) were compared with the previously published results (N=266). Injuries to teeth or dentures were not included in the analysis.

Airway injuries r epresented 9% to 11% of general anesthesia malpractice claims in each decade between 1980 and 2011. The esophagus was the most common site of injury in the current analysis in comparison to the 1999 report (33% vs. 18%, respectively; P<0.01), with perforations comprising 95% of all recent esophageal injury claims. By comparison, injuries to the larynx dropped significantly between the two analyses, from 33% in 1999 to 22% in the current work (P<0.01). Pharyngeal injuries were also common in the current analysis, accounting for 25% of airway injuries, 59% of which were perforations.

All told, perforations of the pharynx or esophagus represented nearly half (46%) of airway injury claims in 2000 to 2011 versus 23% in the 1999 study (P<0.001). Of the 2000 to 2011 perforations, 17% resulted in death. Interestingly, although mortality associated with all airway injury claims remained fairly constant between periods (10% vs. 8%; P=0.35), there was a trend toward more severe outcomes in 2000 to 2011 (9% vs. 5%; P=0.03).

“We’re finding that outcomes are getting worse in these more recent claims,” Dr. Posner explained. “Severe and disabling injuries are increasing; death is still there.” Three-fourths of airway deaths were perforations of the posterior pharynx or esophagus.

When the researchers delved deeper into the data, they found that medical equipment was implicated in 57% of pharyngeal or esophageal perforations. “These were pretty evenly divided,” she noted. “There were some transesophageal echos, but surgical equipment [such as dilators for gastric surgery] was also implicated.” Difficult intubation continued to be associated with one-third of all airway injury claims.

“Another change we saw was that claims for TMJ [temporomandibular joint] injuries have declined quite a bit,” Dr. Posner added. “They were quite prominent in the earlier data [10%], but we’re seeing very few of those in the more recent claims” (4%; P=0.04). Dr. Posner reported the results of the claims review at the ASA’s 2014 annual meeting (abstract A4015) in New Orleans.

Malpractice Claims Skew Reality

Using malpractice claims as a data source comes with its own set of challenges, including the lack of a denominator, which precludes the calculation of incidence or risk. “The American malpractice system is based on a contingency-fee basis, so lawyers get a portion of the settlement,” Dr. Posner explained. “So they tend to only take claims where they think there will be a settlement, or very big settlement. Therefore, malpractice claims are biased toward more severe or permanent injuries.”

Using such claims can also prove advantageous, however. “It gives you a large collection of relatively rare events,” she said. “We can identify patterns of injury. And it can promote others to conduct clinical and lab investigations to try to address these safety issues.

Indeed, addressing airway injuries begins in the perioperative period, where anesthesia providers should not only be aware of the early signs and symptoms of perforation, but should also respond appropriately, particularly in patients exposed to esophageal equipment or difficult intubations. “The ongoing theme we see in these cases is that often the patient complains of a sore throat, but it’s not documented in the record that there was an esophageal pass or if it was a difficult intubation or if equipment was used; there’s no note or any other communication with the postoperative care team.

“It’s important that if there are complaints from the patient about airway problems that the postoperative team knows there may be a problem,” she added. “The trend we see in these is not just the fact that they’re airway injuries. Many of these were delayed in being diagnosed and treated. So these were really severe injuries that got out of control.”

Session co-moderator Joseph R. Ruiz, MD, noted that technological advances might ultimately reduce the incidence of airway-associated injuries. “One of the more noticeable changes in the practice for me has been an increasing utilization of video laryngoscopy, particularly in patients where we think there might be some challenges,” said Dr. Ruiz, who is an associate professor of anesthesiology and perioperative medicine at the University of Texas MD Anderson Cancer Center in Houston. “It does seem that, in general, the risk for airway injury—at least in my experience—is substantially reduced with the use of video laryngoscopy.”

“There weren’t any in this set, so we aren’t seeing any injuries from video laryngoscopy,” Dr. Posner replied. “We didn’t pick up any GlideScope [Verathon] injuries, although there are case reports of that happening. In addition, it does generally take five years or so for an injury to result in a closed claim.”