Laryngeal mask airway in air transport when intubation fails: case report

Air medical rapid sequence intubation: How can we achieve success?

Airway management is an essential component of the air medical transport of critically ill or injured patients. Many controversies surround the use of rapid sequence intubation (RSI) in the prehospital setting. The challenges of establishing an airway in this environment may exceed those in the hospital. However, it is clear that the same high standards for success demanded in the hospital must be applied to RSI in the prehospital setting for the practice to be accepted and result in positive outcomes. Given their volume of high acuity patients, air medical providers are ideal candidates for performing prehospital RSI. Undertaking this responsibility requires commitment to training and quality improvement. We present the components required to establish and maintain a successful air medical RSI program.

Comparison of the intubating laryngeal mask airway versus laryngoscopy in the Bell 206-L3 EMS helicopter

INTRODUCTION

The purpose of this study is to compare intubation success rate and time to intubation for the intubating laryngeal mask airway (I-LMA) versus direct laryngoscopy (DL) using a manikin model during a simulated in-flight scenario.

SETTING

The setting for the study was a University hospital-based air medical program.

METHODS

This was a prospective, randomized, crossover trial. Eight nurses and 7 paramedics were randomly assigned to perform 3 intubations with either the I-LMA or DL first and then 3 intubations using the alternate technique. Descriptive statistics, 95% confidence intervals (CIs) of means, and Fisher's Exact test were conducted for comparisons.

RESULTS

Fifteen set-ups and 45 intubations were performed with each technique. Previous experience was 74 mm (95% CI 64-84) with DL and 18 mm (95% CI 9-27) with the I-LMA. Set-up time was 33 seconds (95% CI 26-40) for DL and 40 seconds (95% CI 29-50) for I-LMA. Time to intubation was 12 seconds (95% CI 10-14) for DL and 39 seconds (95% CI 31-48) for I-LMA. Success rate was 100% for DL and I-LMA placement and 98% for intubation through the I-LMA. Crew rated difficulty of DL 13 mm (95% CI 6-20), placing the I-LMA 23 mm (95% CI 13-32), and intubating through the I-LMA 17 mm (95% CI 10-24).

CONCLUSION

Intubation success was very high for both DL and the I-LMA, despite less flight crew experience with the I-LMA. Total time to intubation was longer with the I-LMA but still less than 1 minute. The flight crews considered both techniques easy to perform. The I-LMA appears to be a useful adjunct for airway management in the Bell 206-L3 helicopter.

Etomidate versus succinylcholine for intubation in an air medical setting

The objective was to compare rates of successful endotracheal intubation (ETI) and requirement for multiple ETI attempts in patients receiving etomidate (ETOM) versus succinylcholine (SUX). This retrospective study analyzed adults in whom oral ETI was attempted by a helicopter EMS (HEMS) service between July 1997 to July 1999. Data were from records of the HEMS service, which uses a RN/EMTP crew; analysis was with chi-square and logistic regression (P = .05). ETI was successful in 269 (97.8%) of 275 patients, with multiple attempts occurring in 54 (20.1%) of 269. Success rates for SUX (209 of 213, 98.1%) and ETOM (60 of 62, 96.8%) were similar (P = .62). However, of 60 ETOM patients successfully intubated, 7 (11.7%) required rescue succinylcholine. When these patients are tallied as ETOM failures and SUX successes, resultant success rates for ETOM (86.9%) and SUX (98.2%) are different (P = .001). ETOM patients were more likely (P = .004) than SUX patients to require multiple attempts (33.3% versus 16.3%). ETI success rates were high in patients receiving SUX or ETOM as primary adjuncts for airway control, but initial success was more likely with SUX, and ETOM patients were more likely to require multiple attempts.

Flight crew airway management in four settings: a six-year review

OBJECTIVE

To analyze flight crew airway management in four different settings (in flight, at trauma scenes, in ambulance, and in referring hospitals) and in two different aircraft used by the same helicopter EMS (HEMS) service. The null hypothesis was that there was no association between practice setting, or aircraft, and airway practices or success rate.

METHODS

This retrospective study analyzed all patients in whom advanced airway management was attempted by the HEMS service during the study period October 1991 through October 1997. Data used were from flight records of Boston MedFlight Critical Care Transport Service, which uses a nurse/paramedic crew and had a paralytic-assisted intubation protocol in place. Data were analyzed with chi-square and Fisher's exact testing, risk ratio analysis, and logistic regression.

RESULTS

Advanced airway management was attempted in 722 patients, with an airway placed in 705 (97.8%). Intubation success was unrelated to site of airway management (p = 0.14), but patients were more likely to have intubation attempted prior to flight (as opposed to in flight) if the crew were in the AS365N2 Dauphin as compared with the BK-117 (p<0.0001). In addition, patients were 0.77 times as likely (95% confidence interval, 0.68-0.88) to receive paralytic-facilitated intubation if airway management occurred in the hospital setting as compared with other sites.

CONCLUSIONS

While HEMS crew airway management success rates are equally high in all practice settings, airway management decision making and practice appear to be significantly influenced by practice setting and aircraft type. These data support contentions that nonphysician HEMS crews can effectively manage airways in a variety of circumstances.

Use of the laryngeal mask airway in air transport when intubation fails

BACKGROUND

A prospective, nonrandomized cohort study was conducted to determine the effectiveness of the laryngeal mask airway (LMA) for management of the difficult airway in patients requiring air transport.

METHODS

The LMA was inserted in those patients who could not be successfully intubated. Data were collected to evaluate the effectiveness of the LMA and to document any complications attributed to its use.

RESULTS

Inclusion criteria were met in 17 of the 25 patients receiving an LMA. The device was inserted successfully in 16 of 17 of the patients (94%). In-flight oxygen saturation ranged from 97 to 100%, and end-tidal carbon dioxide ranged from 24 to 35 mm Hg. At arrival, initial arterial blood gas values indicated adequate oxygenation in all patients and adequate ventilation in 15 of 16 patients (94%). There was no evidence of complications.

CONCLUSION

Our patient data show that when conventional methods have failed, the LMA can be safely, rapidly, and effectively used for temporary airway control.

Combat trauma airway management: endotracheal intubation versus laryngeal mask airway versus combitube use by Navy SEAL and Reconnaissance combat corpsmen

BACKGROUND

Airway management takes precedence regardless of what type of life support is taking place. The gold standard for airway control and ventilation in the hands of the experienced paramedic remains unarguably the endotracheal tube. Unfortunately, laryngoscopy and endotracheal intubation require a skilled provider who performs this procedure on a frequent basis. Special Operations corpsmen and medics receive training in the use of the endotracheal tube, but they use it infrequently. The use of alternative airways by Navy SEAL and Reconnaissance combat corpsmen has not been evaluated. Our objective was to compare the ability of Special Operations corpsmen to use the endotracheal tube (ETT), laryngeal mask airway (LMA), and esophageal-tracheal combitube (ETC) under combat conditions.

METHODS

This study used a prospective, randomized, crossover design. Twelve Navy SEAL or Reconnaissance combat corpsmen participated in a 2-week Advanced Battlefield Trauma course. During the first week, instruction included the use of ETT, LMA, and ETC, viewing of videotapes for ETC and LMA, and mannequin training. The Special Operations corpsmen were required to reliably insert each airway within 40 seconds. During the second week, participants dealt with a number of active combat trauma scenarios under fire in combat conditions. Each SEAL or Reconnaissance corpsman was asked to control his "casualty's" airway with a randomized device. All participants were evaluated in the use of each of the three airways.

RESULTS

Thirty-six airway insertions were evaluated. No failures occurred. All incorrect placements were detected and corrected. Mean time to place the ETT was 36.5 seconds versus 40.0 seconds for the ETC. The LMA insertion time of 22.3 seconds was significantly shorter than the other times (p < 0.05). The mean number of attempts per device was similar with all devices: LMA (1.17), ETC (1.17), and ETT (1.25).

CONCLUSION

The Special Operations corpsmen easily learned how to use the ETC and LMA. In this study, they showed the ability to appropriately use the ETT as well as the ETC and LMA. For SEAL corpsmen, the alternative airways should not replace the ETT; however, on occasion an advanced combat casualty care provider may not be able to use the laryngoscope or may be unable to place the ETT. The LMA and ETC are useful alternatives in this situation. If none of these airways are feasible, cricothyrotomy remains an option. Regardless of the airway device, refresher training must take place frequently.