The PTL, Combitube, laryngeal mask, and oral airway: a randomized prehospital comparative study of ventilatory device effectiveness and cost-effectiveness in 470 cases of cardiorespiratory arrest

Advances in airway management

Emergency ventilation is an essential component of basic life support. Respiratory emergencies occur far more frequently than cardiac arrest and, if not treated promptly and effectively, may lead to cardiac arrest. Many respiratory emergencies require assisted ventilation to prevent the occurrence of hypoxemia, hypercarbia, and cardiac decompensation. Emergency assisted ventilation is often difficult to perform and is associated with several adverse complications, such as gastric inflation, regurgitation, and pulmonary aspiration. The American Heart Association sponsored conferences in 1999 and 2000 to review and revise guidelines for cardiopulmonary resuscitation. This article reviews the science behind guideline changes related to pulmonary resuscitation and discusses recent advances in emergency airway management, focusing on noninvasive techniques for ventilation (mouth-to-mouth ventilation, bag-mask ventilation) and alternative airway devices (laryngeal mask airway, the Combitube).

Paramedic-performed rapid sequence intubation of patients with severe head injuries

STUDY OBJECTIVE

We evaluate the ability of paramedic rapid sequence intubation (RSI) to facilitate intubation of patients with severe head injuries in an urban out-of-hospital system.

METHODS

Adult patients with head injuries were prospectively enrolled over a 1-year period by using the following inclusion criteria: Glasgow Coma Scale score of 3 to 8, transport time of greater than 10 minutes, and inability to intubate without RSI. Midazolam and succinylcholine were administered before laryngoscopy, and rocuronium was given after tube placement was confirmed by means of capnometry, syringe aspiration, and pulse oximetry. The Combitube was used as a salvage airway device. Outcome measures included intubation success rates, preintubation and postintubation oxygen saturation values, arrival arterial blood gas values, and total out-of-hospital times for patients intubated en route versus on scene.

RESULTS

Of 114 enrolled patients, 96 (84.2%) underwent successful endotracheal intubation, and 17 (14.9%) underwent Combitube intubation, with only 1 (0.9%) airway failure. There were no unrecognized esophageal intubations. On arrival at the trauma center, median oxygen saturation was 99%, mean arrival PO2 was 307 mm Hg, and mean arrival PCO2 was 35.8 mm Hg. Total out-of-hospital times were higher when RSI was performed on scene (26 versus 13 minutes).

CONCLUSION

Paramedics can use RSI protocols that include neuromuscular blocking and sedative agents to facilitate intubation of patients with head injuries.

Tracheal esophageal combitube: a useful airway for morbidly obese patients who cannot intubate or ventilate

The tracheal esophageal combitube has been successfully used in many difficult airway circumstances. We report the dramatic case of a morbidly obese patient with a well-known difficult airway who was successfully rescued from a cannot ventilate-cannot intubate situation in our critical care unit by using the tracheal esophageal combitube. Surgical tracheostomy was performed while she was mechanically ventilated through the tracheal esophageal combitube. The tracheal esophageal combitube is a very important device that should be kept available in all cases of morbidly obese airway management.

[New aspects and perspectives on cardiac arrest]

OBJECTIVES

To analyse the current knowledge based on the experimental and the clinical research studies focused on the main fields of cardiopulmonary resuscitation.

DATA SOURCES

International guidelines and recent review articles. Data collected from the Medline database with the key word: cardiac arrest.

STUDY SELECTION

Research studies published during the last ten years were reviewed. Relevant clinical information was extracted and discussed when it induced changes in guidelines.

DATA SYNTHESIS

Promising improvements on basic and advanced life supports are proposed. Chest compressions prevail over ventilation. Alternatives to classical chest compressions are tested. Ventilatory volume must be reduced from 1000 to approximatively 500 mL for each breath with oxygen. Biphasic waveform defibrillators and automated external defibrillators will be considered as the best devices in the near future. Some non-catecholaminergic vasopressors could reduce the use of epinephrine for advanced cardiac life support. Lidocaine could be replaced by amiodarone as anti-arrhythmic drug of choice. New post-resuscitation therapeutic strategies are evaluated, especially coronary reperfusion when the cause of cardiac arrest is cardiac.

CONCLUSION

Many fields of cardiopulmonary resuscitation are investigated. Some relevant informations are included in the last international guidelines published in 2000, but most of them need complementary studies before other changes could be recommended for routine practice.

Alternative ventilation strategies in cardiopulmonary resuscitation

The introduction of the 2000 Guidelines for Cardiopulmonary Resuscitation emphasizes a new, evidence-based approach to the science of ventilation during cardiopulmonary resuscitation (CPR). New laboratory and clinical science underemphasizes the role of ventilation immediately after a dysrhythmic cardiac arrest (arrest primarily resulting from a cardiovascular event, such as ventricular defibrillation or asystole). However, the classic airway patency, breathing, and circulation (ABC) CPR sequence remains a fundamental factor for the immediate survival and neurologic outcome of patients after asphyxial cardiac arrest (cardiac arrest primarily resulting from respiratory arrest). The hidden danger of ventilation of the unprotected airway during cardiac arrest either by mouth-to-mouth or by mask can be minimized by applying ventilation techniques that decrease stomach gas insufflation. This goal can be achieved by decreasing peak inspiratory flow rate, increasing inspiratory time, and decreasing tidal volume to approximately 5 to 7 mL/kg, if oxygen is available. Laboratory and clinical evidence recently supported the important role of alternative airway devices to mask ventilation and endotracheal intubation in the chain of survival. In particular, the laryngeal mask airway and esophageal Combitube proved to be effective alternatives in providing oxygenation and ventilation to the patient in cardiac arrest in the prehospital arena in North America. Prompt recognition of supraglottic obstruction of the airway is fundamental for the management of patients in cardiac arrest when ventilation and oxygenation cannot be provided by conventional methods. "Minimally invasive" cricothyroidotomy devices are now available for the professional health care provider who is not proficient or comfortable with performing an emergency surgical tracheotomy or cricothyroidotomy. Finally, a recent device that affects the relative influence of positive pressure ventilation on the hemodynamics during cardiac arrest has been introduced, the inspiratory impedance threshold valve, with the goal of maximizing coronary and cerebral perfusion while performing CPR. Although the role of this alternative ventilatory methodology in CPR is rapidly being established, we cannot overemphasize the need for proper training to minimize complications and maximize the efficacy of these new devices.

Current status of the Combitube: a review of the literature

The Combitube (Tyco-Healthcare-Kendall-Sheridan, Mansfield, MA) is an easily inserted and highly efficacious device to be used as an alternative airway whenever conventional ventilation fails. The Combitube allows ventilation and oxygenation whether the device locates in the esophagus (very common) or the trachea (rare). In this report, we review studies that suggest the Combitube is a valuable and effective airway in the emergency and prehospital settings, in cardiopulmonary resuscitation, in elective surgery, and in critically ill patients in the intensive care unit. Also reviewed are studies that demonstrate the superiority of the Combitube over other supraglottic ventilatory devices in resuscitation with respect to success rates with insertion and ventilation. Contrary to the Laryngeal Mask Airway, the Combitube may help in patients with limited mouth opening. The Combitube may be of special benefit in patients with massive bleeding or regurgitation, and it minimizes the risk of aspiration.

Airway and ventilation management

Airway management is fundamental to ACLS. Success with any airway device relies as much on the operator's experience and skill as on the device itself. The purpose of using an airway device is to provide a patent route for ventilating the lungs and to protect against pulmonary aspiration. Training should emphasize the importance of confirming that the airway device is positioned correctly and that the lungs can be ventilated effectively. If airway intervention is to have a positive effect on outcome, the choice of airway device is less important than thorough training, ongoing experience and review, and close attention to complications. Regardless of whether a provider chooses to use the LMA, the combitube, or the tracheal tube, providers must be familiar with more than one method of airway management because of the possibility of failure to insert or ventilate with their primary airway device of choice.

Update in pediatric resuscitation

This article updates research concerning the resuscitation of a pediatric patient. The topics discussed include the state of pediatric life support, the current guidelines, the management of those guidelines, and coping with death.

Use of the laryngeal tube for out-of-hospital resuscitation

Every physician involved in emergency medicine should be familiar with alternative techniques for managing the difficult airway. We report a case of a patient who was successfully ventilated and oxygenated with a laryngeal tube, when tracheal intubation failed. Ventilation was possible even during continuous chest compressions. Airway equipment, including one supraglottic alternative for patients of all ages and a set for cricothyroidotomy, for those experienced in its use, should be available on every ambulance equipped for advanced life support.

Use of the esophageal tracheal combitube by basic emergency medical technicians

The most appropriate airway device for use in EMS systems staffed by basic skilled EMTs with (EMT-Ds) or without (EMT-Bs) defibrillation capabilities is still a matter of debate. The purpose of this study was to assess the feasibility, safety and effectiveness of the Esophageal Tracheal Combitube (ETC) when used by EMT-Ds in cardiorespiratory arrest patients of all etiologies. The EMTs had automatic external defibrillator (AED) training but no prior advanced airway technique skills. The prehospital intervention was reviewed using the EMTs cardiac arrest report, the AED tape recording of the event and the assessment of the receiving emergency physician. The patients' hospital records and autopsy report were reviewed in search of complications. Eight hundred and thirty-one adult cardiac arrest patients were studied. Placement was successful in 725 (95.4%) of the 760 patients where it was attempted and ventilation was successful in 695 (91.4%). Immediate complications encountered, but not necessarily related to the use of the ETC, were; subcutaneous emphysema (18), tension pneumothorax (5), blood in the oropharynx (15), and swelling of the pharynx (three). An autopsy was done in 133 patients; no esophageal lesions or significant injury to the airway structures were observed. Our results suggest that EMT-Ds can use the ETC for control of the airway and ventilation in cardiorespiratory arrest patients safely and effectively.

Difficult airway management in the emergency department

Most airway management in the emergency department is straightforward and readily accomplished by the emergency physician. The exact incidence of difficult intubations is difficult to discern from available evidence, but these are probably more frequent in the Emergency Department than in the operating room, given the urgent nature of the procedure and the lack of preparation of the patient population. A variety of adjuncts for airway management are available to assist in both intubation and ventilation. The utility of these adjuncts is detailed in this review, with emphasis on techniques most useful to the emergency physician.

The development of a register of randomized controlled trials in prehospital trauma care

OBJECTIVES

To establish a register of randomized controlled trials of interventions in the prehospital care of trauma patients.

METHODS

A systematic search was conducted for all randomized controlled trials of interventions in the prehospital care of trauma patients. The search included the Cochrane Controlled Trial Register, the Cochrane Injuries Group Specialised Register, Medline, EMBASE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), Science Citation Index, National Research Register, Dissertation Abstracts, and PubMed for the time period 1966-2000. There were no language restrictions. In addition, full-text hand searching of a range of relevant journals was done, and the authors of included trials were contacted.

RESULTS

The combined search strategy identified 16,037 potentially eligible records, of which 28 were reports of randomized controlled trials evaluating prehospital trauma care interventions. After excluding duplicate reports, there were 24 separate randomized controlled trials including 6,806 patients. The largest and smallest trials involved 1,309 and 30 trauma patients, respectively.

CONCLUSIONS

This register will facilitate the conduct of systematic reviews of the effectiveness of interventions in prehospital trauma care. However, despite the extensive searching, very few randomized trials in this area were found. In view of the absence of evidence for the effectiveness of many of the interventions that are used in the prehospital care of trauma patients, further randomized controlled trials are required.

Prehospital and resuscitative airway care: should the gold standard be reassessed?

In the context of prehospital care and resuscitation, tracheal intubation has been regarded as the standard in airway treatment. The evidence for this status is rather weak. It does not take into account the level of training and experience of the personnel attempting intubation, and whether they use neuromuscular blockers. In unskilled hands, attempted tracheal intubation is harmful; unrecognized esophageal intubation is disastrous. When healthcare providers lack adequate skills in tracheal intubation, alternative airway devices, such as the laryngeal mask airway or the Combitube, may be better options than a simple facemask. Healthcare personnel using any of these devices should be adequately trained and maintain frequent practice.

Respiratory failure after tracheal extubation in a patient with halo frame cervical spine immobilization--rescue therapy using the Combitube airway

A 78-yr-old man, with halo frame cervical spine immobilization, suffered rapid respiratory deterioration after tracheal extubation in the intensive care unit. Control of the airway was difficult as bag-valve-mask ventilation was ineffective, tracheal intubation was known to be difficult from management of a previous episode of respiratory failure on the ward, and laryngeal mask insertion proved impossible. Rescue therapy using a Combitube airway is described and discussed.

The laryngeal mask airway: a comprehensive review for the Emergency Physician

The Laryngeal Mask Airway (LMA) was developed in the 1980s, but has only recently begun to be used in Emergency Medicine. The LMA affords effective assisted ventilation without requiring endotracheal intubation or visualization of the glottis. In doing so, it is more efficacious than a bag-valve-mask apparatus, although the risk of aspiration of gastric contents persists, particularly if the device is not properly placed. The LMA also has significant potential utility in management of the difficult airway. Most reported clinical experience with the LMA has come from the operating room. This article provides an overview of the extensive potential utility of the LMA in the Emergency Department and prehospital settings as well as a comprehensive review of the pertinent advantages, disadvantages, and complications associated with its use.

Design and implementation of a controlled trial of pediatric endotracheal intubation in the out-of-hospital setting

This article describes the design and implementation of the Pediatric Airway Management Project. The project was completed January 1, 1997, and evaluated the effectiveness of endotracheal intubation relative to bag-valve-mask ventilation in improving survival to hospital discharge and neurologic outcome in children, the effect of training on paramedic airway management skills and self-efficacy, the length of time the skills can be retained, and the costs of training and retraining. The main focus of project design was the implementation of a controlled trial comparing methods of airway management for acutely ill and injured pediatric patients in the out-of-hospital setting. To date, this project is the largest prospective, controlled, out-of-hospital study of the care of children ever reported. Barriers to implementation of a study of this size are described.

Successful prehospital airway management by EMT-Ds using the combitube

OBJECTIVE

To evaluate the ability to train emergency medical technicians-defibrillation (EMT-Ds) to effectively use the Combitube for intubations in the prehospital environment.

METHODS

This was an 18-month prospective field study in which EMT-Ds were trained how and in what situations to use the Combitube. Data were then obtained for all patients in whom Combitube insertion was attempted. Indications for use of the Combitube included: unconsciousness without a purposeful response, absence of the gag reflex, apnea or respiratory rate less than 6 breaths/min, age more than 16 years, and height at least 5 feet tall. Contraindications were: obvious signs of death, intact gag reflex, inability to advance the device due to resistance, or known esophageal pathology. Data were entered prospectively from the San Diego County EMS QANet database for prehospital providers.

RESULTS

Twenty-two EMT-D provider agencies, involving approximately 500 EMT-Ds, were included as study participants. Combitube insertions were attempted in 195 prehospital patients in cardiorespiratory arrest, with appropriate indication for Combitube use. An overall successful intubation rate (defined as the ability to successfully ventilate) of 79% was observed. Identical success rates for medical and trauma patients were noted. The device was placed in the esophagus 91% of the time. Resistance during insertion was the major reason for unsuccessful Combitube intubations. An overall hospital admission rate of 19% was observed. No complications were reported.

CONCLUSION

EMT-Ds can be trained to use the Combitube as a means of establishing an airway in the prehospital setting. Future studies will need to further evaluate its effect on patient outcome.

A literature review of the prehospital use of neuromuscular blocking agents by air medical personnel to facilitate endotracheal intubation

Air medical personnel in the United States have used neuromuscular blocking agents to facilitate endotracheal intubation in the field for more than a decade. This literature review examines 15 studies to investigate their experience and explores the following specific areas: the intubation success rate in patients who did or did not receive these agents, the intubation success rate of air medical personnel before and after they incorporated these agents into their practice, the neuromuscular blocking agents and adjunct medications used by air medical personnel, and the disposition of patients who could not be intubated after an agent was given. The data suggest that, overall, air medical personnel use these agents safely and effectively. Suggestions are offered for future studies, including examining ground time when agents are used to facilitate intubation, complications of their use in this setting, and the use of simulators to train personnel in the administration of these medications.

The oesophageal-tracheal Combitube Small Adult

Airway management during gynaecological laparoscopy is complicated by intraperitoneal carbon dioxide inflation, Trendelenburg tilt, increasing airway pressures and pulmonary aspiration risk. We investigated whether the oesophageal-tracheal Combitube 37 Fr SA is a suitable airway during laparoscopy. One hundred patients were randomly allocated to receive either the Combitube SA (n = 49) or tracheal intubation (n = 51). Oesophageal placement of the Combitube was successful at the first attempt [16 (3) s]. Peak airway pressures were 25 (5) cmH2O. An airtight seal was obtained using air volumes of 55 (13) ml (oropharyngeal balloon) and 10 (1) ml (oesophageal cuff). Significant correlations were observed between patient's height and weight and the balloon volumes necessary to produce a seal. Similar findings were recorded for the control group, with tracheal intubation being difficult in three patients. The Combitube SA provided a patent airway during laparoscopy. Non-traumatic insertion was possible and an airtight seal was provided at airway pressures of up to 30 cmH2O.

Epinephrine application via an endotracheal airway and via the Combitube in esophageal position

OBJECTIVE

To compare plasma concentrations and cardiovascular effects of epinephrine after application via a conventional endotracheal airway and via the esophageal lumen of a new emergency airway, the esophageal tracheal Combitube.

DESIGN

Prospective, randomized study.

SETTING

Center for Biomedical Research, University of Vienna.

SUBJECTS

Fourteen juvenile swine received either an endotracheal tube (Group A) or a Combitube in esophageal position (Group B).

INTERVENTIONS

In Part I of the study, epinephrine was administered during spontaneous beating of the heart; in Part II, epinephrine was administered during cardiopulmonary resuscitation, using a ten-fold higher dosage in Group B, respectively.

MEASUREMENTS

Plasma epinephrine levels were measured 1, 2, 3, 5, 7, 10, 15, and 30 mins after application. Systolic arterial blood pressure and cardiac output in Part I, and end-tidal CO2 and coronary perfusion pressure in Part II were recorded.

MAIN RESULTS

In Part I, increased levels of plasma epinephrine and systolic arterial pressure were maintained significantly longer in Group B when compared with Group A. In Part II, no significant differences between the groups were found with regard to plasma epinephrine levels and hemodynamic variables.

CONCLUSION

Epinephrine applied via the esophageal lumen of the Combitube in a ten-fold higher dosage has similar effects on plasma epinephrine levels and hemodynamic variables compared to endotracheal administration.

Tracheal injury as a sequence of multiple attempts of endotracheal intubation in the course of a preclinical cardiopulmonary resuscitation

Management of the difficult airway requires an appropriate approach based on personal clinical experiences. For every physician involved in rescue and emergency medicine, it is important to know the difficult airway algorithm and be familiar with alternative techniques of managing the difficult airway. We report a case of tracheal injury caused by multiple attempts at intubating the trachea. Based on current knowledge, apart from surgical equipment for cricothyroidotomy the laryngeal mask airway (LMA) and the Combitube (ETC) should be available on any ambulance vehicle staffed by an emergency physician. In future, blind intubation through the intubating laryngeal mask airway (ILMA) could offer a new opportunity.

Management of difficult airways in the field

Establishing an airway is a critical first step in emergency management of comatose patients and those who have suffered head trauma, cardiac arrest, or respiratory failure. The use of succinylcholine, a paralytic, to assist with intubation is a safe and effective way to help establish an airway under difficult circumstances, in the prehospital setting. It requires excellent intubation skills, a thorough knowledge of the indications and contraindications of its use, and similar knowledge of any other medications employed. Succinylcholine-assisted intubation should never be implemented without close physician monitoring. Therefore, under the auspices of strong medical control, it is an effective way to establish adequate oxygenation and to control ventilation in some of the most critical patients encountered in the field. Additionally, because physical examination alone is not dependable for ensuring proper endotracheal tube placement, an objective confirmatory device such as an end-tidal carbon dioxide detector should be used.

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.

The unanticipated difficult airway with recommendations for management

PURPOSE

To review the current literature and generate recommendations on the role of newer technology in the management of the unanticipated difficult airway.

METHODS

A literature search using key words and filters of English language and English abstracted publications from 1990-96 contained in the Medline, Current Contents and Biological Abstracts databases was carried out. The literature was reviewed and condensed and a series of evidence-based recommendations were evolved.

CONCLUSIONS

The unanticipated difficult airway occurs with a low but consistent incidence in anaesthesia practice. Difficult direct laryngoscopy occurs in 1.5-8.5% of general anaesthetics and difficult intubation occurs with a similar incidence. Failed intubation occurs in 0.13-0.3% general anaesthetics. Current techniques for predicting difficulty with laryngoscopy and intubation are sensitive, non-specific and have a low positive predictive value. Assessment techniques which utilize multiple characteristics to derive a risk factor tend to be more accurate predictors. Devices such as the laryngeal mask, lighted stylet and rigid fibreoptic laryngoscopes, in the setting of unanticipated difficult airway, are effective in establishing a patient airway, may reduce morbidity and are occasionally lifesaving. Evidence supports their use in this setting as either alternatives to facemask and bag ventilation, when it is inadequate to support oxygenation, or to the direct laryngoscope, when tracheal intubation has failed. Specifically, the laryngeal mask and Combitube have proved to be effective in establishing and maintaining a patent airway in "cannot ventilate" situations. The lighted stylet and Bullard (rigid) fibreoptic scope are effective in many instances where the direct laryngoscope has failed to facilitate tracheal intubation. The data also support integration of these devices into strategies to manage difficult airway as the new standard of care. Training programmes should ensure graduate physicians are trained in the use of these alternatives. Continuing medical education courses should allow physicians in practice the opportunity to train with these alternative devices.

Choice of airway devices for 12,020 cases of nontraumatic cardiac arrest in Japan

OBJECTIVE

This retrospective study was designed to determine the choice of airway devices used for nontraumatic, out-of-hospital cardiac arrest patients and to evaluate the success and failure of insertion and airway control/ventilation by three airway adjuncts, the Combitube, the esophageal gastric tube airway (EGTA), and the laryngeal mask (LM), which were used in conjunction with the bag-valve-mask (BVM) by emergency life-saving technicians (ELSTs) in Japan.

METHODS

A survey of 1,085 ELSTs was performed to identify the type of airway devices, the success rates of airway insertion, the effectiveness of airway control/ventilation in comparison with the BVM prior to each airway insertion, and associated complications. The type of education for airway skills was also surveyed.

RESULTS

1,079 surveys were returned and 12,020 cases of cardiac arrest were studied. Choice of airway devices: BVM, 7,180 cases; EGTA, 545 cases; Combitube, 1,594 cases; and LM, 2,701 cases. Successful insertion rates on the first attempt: EGTA, 82.7%; Combitube, 82.4%; and LM, 72.5% (p < 0.0001). Failed insertions: EGTA, 8.2%; Combitube, 6.9%; and LM, 10.5% (p < 0.0001). Successful ventilation: EGTA, 71.0%; Combitube, 78.9%; and LM, 71.5% (p < 0.0004). Six cases of aspiration were reported in the LM group, whereas nine cases of soft-tissue injuries, including esophageal perforation, were reported in the Combitube group. 17.8% had vomited either prior or during airway placement.

CONCLUSION

The Combitube appears to be the most appropriate choice among the airway devices examined. However, serious injuries to the tissues, though they rarely occurred in the study, remain a major concern.