Laryngeal tube tied to worse placement success, complications in OHCA

Use of the laryngeal tube (LT) for out-of-hospital cardiac arrest (OHCA) by paramedics in Singapore leads to poorer placement success and more complications as compared with laryngeal mask airway (LMA), a study has found.

“This preliminary study served to identify gaps to improve the training of paramedics in using LT, since the group had fewer successful placements and more complications as well as low paramedic compliance,” the researchers said.

This real-world, prospective, cluster-randomized crossover study included OHCA patients aged >13 years who were suitable for resuscitation. The researchers performed per-protocol analysis and used multivariate binomial logistic regression analysis to compare the association between airway device group and outcomes.

A total of 965 patients with OHCAs from March 2016 to January 2018 were identified, of whom 905 met the eligibility criteria: 502 (55.5 percent) received LT while 403 (44.5 percent) received LMA. Among patients in the LT group, only 174 received the device due to noncompliance. [Singapore Med J 2020;doi:10.11622/smedj.2020119]

The primary outcome of placement success was lower for LT than for LMA (adjusted odds ratio [OR], 0.52, 95 percent confidence interval [CI], 0.31–0.90). LT use was also associated with more complications (adjusted OR, 2.82, 95 percent CI, 1.64–4.86).

The adjusted OR for prehospital return of spontaneous circulation (ROSC) was comparable in both groups. In a modified intention-to-treat analysis, outcomes between the two groups were similar to the per-protocol analysis.

“It was difficult to determine if the poorer outcomes were attributed to the LT itself or to the unfamiliarity with the device,” the researchers said. “The LMA has been used by Singapore paramedics for over a decade, and prior to the study, none of the paramedics had any experience with LT.”

Familiarity bias was significant in this study. A survey conducted immediately after the LT training showed that most paramedics found LT easy to use, and the initial usage rate supported this, but apparently paramedics were still uncomfortable with using it. This was possibly due to a much greater familiarity with the use of the LMA,” according to the researchers.

Earlier studies showed that using LT instead of endotracheal intubation improved OHCA survival, but some studies also reported that LT use was associated with severe complications, including life-threatening tongue swelling, massive gastric distension, and incorrect placement. [JAMA 2018;320:769-778; Resuscitation 2014;85:1629-1632; Anaesthesist 2014;63:589-596]

“A follow-up study is thus warranted, with more rigorous study design, after intensive training and involving paramedics with a longer period of experience in using LT to better evaluate the efficacy of whether the LT truly results in improved patient outcomes,” the researchers said.

“Time to placement of airway device should also be assessed. Other clinical outcomes, such as survival to admission and discharge, can also be looked into, in addition to a qualitative evaluation of paramedic attitudes towards new airway devices,” they added.