Students insert the laryngeal tube quicker and more often successful than the esophageal–tracheal combitube in a manikin

Performance of the laryngeal tube for airway management during cardiopulmonary resuscitation

INTRODUCTION

Sudden cardiac arrest is one of the leading causes of death in Europe and the whole world. Effective chest compressions and advanced airway management have been shown to improve survival rates. Supraglottic airway devices such as the laryngeal tube (LT) are a well-known strategy for patients with cardiac arrest during both basic (BLS) and advanced life support (ALS). This systematic literature review aimed to summarize current data for using the LT when performing BLS and ALS.

EVIDENCE ACQUISITION

Recent data on the use of the LT during cardiopulmonary resuscitation (CPR) was gathered by using the Medline database and a specific search strategy. Terms were used in various order and combinations without time restrictions. A total of N.=1005 studies were identified and screened by two experienced anesthesiologists/emergency physicians independently. Altogether, data of N.=19 relevant papers were identified and included in the analysis.

EVIDENCE SYNTHESIS

Using the LT showed fast and easy placement with high success rates (76% to 94%) and was associated with higher short-term survival as compared to other strategies for initial airway management (2.2% vs. 1.4%). Quality of CPR such as chest compression fraction (CCF) before and after LT-insertion is improved (75% vs. 59%). For long-term survival, the LT showed lower survival rates.

CONCLUSIONS

Especially as initial device of airway management (for inexperienced staff), the use of a LT is easy and results in a fast insertion. The advantages of the LT as compared to bag mask ventilation and endotracheal intubation are inhomogeneous in recent literature.

Feasibility and speed of insertion of seven supraglottic airway devices under simulated airway conditions

OBJECTIVES

Endotracheal intubation (ETI) is considered the gold standard for protecting the airway. Alternative devices for airway protection have been developed that can be used by untrained personnel, by those with less experience, and for when ETI is not possible. The main goals of our study were to evaluate the success rate and speed of insertion of different supraglottic airway devices and to determine whether the devices could be properly inserted under simulated critical conditions.

METHODS

Fifty medical students used an airway simulation trainer (Laerdal SimMan 3G) to assess the success rate and time used to insert seven different supraglottic airway devices under simulated physiologic and pathologic conditions in two different runs.

RESULTS

Although all airway devices could be inserted without problems, only the Combitube and the EasyTube could be successfully inserted in simulations of trismus, limited mobility of the cervical spine, or a combination of pathologic conditions such as trismus plus limited mobility of the spine and trismus plus tongue edema. The insertion time was significantly longer with LMA Unique, Fastrach, and I-Gel devices in both the first and second runs.

CONCLUSION

The Combitube and the EasyTube were most easily inserted under simulated conditions such as trismus, limited mobility of the cervical spine, and combined pathologic conditions. Although all devices are useful for establishing an airway by nontrained medical students in standard simulations, we suggest that the Combitube and the EasyTube may offer advantages in difficult airway situations.

Effect of the laryngeal tube on the no-flow-time in a simulated two rescuer basic life support setting with inexperienced users

INTRODUCTION

Intubation with a laryngeal tube (LT) is a recommended alternative to endotracheal intubation during advanced life support (ALS). LT insertion is easy; therefore, it may also be an alternative to bag-mask ventilation (BMV) for untrained personnel performing basic life support (BLS). Data from manikin studies support the influence of LT on no-flow-time (NFT) during ALS.

METHODS

We performed a prospective, randomized manikin study using a two-rescuer model to compare the effects of ventilation using a LT and BMV on NFT during BLS. Participants were trained in BMV and were inexperienced in the use of a LT.

RESULTS

There was no significant difference in total NFT with the use of a LT and BMV (LT: mean 83.1 ± 37.3 s; BMV: mean 78.7 ± 24.5 s; p = 0.313), but we found significant differences in the progression of the scenario: in the BLS-scenario, the proportion of time spent performing chest compressions was higher when BMV was used compared to when a LT was used. The quality of chest compressions and the ventilation rate did not differ significantly between the two groups. The mean tidal volume and mean minute volume were significantly larger with the use of a LT compared with the use of BMV.

CONCLUSIONS

In conclusion, in a two-rescuer BLS scenario, NFT is longer with the use of a LT (without prior training) than with the use of BMV (with prior training). The probable reasons for this result are higher tidal volumes with the use of a LT leading to longer interruptions without chest compressions.

Impact of laryngeal tube use on chest compression fraction during out-of-hospital cardiac arrest. A prospective alternate month study

AIM

Supraglottic devices are thought to allow efficient ventilation and continuous chest compressions during cardiac arrest. Therefore, the use of supraglottic devices could increase the chest compression fraction (CCF), a critical determinant of patient survival. The aim of this study was to assess the CCF in out-of-hospital cardiac arrest (OHCA) patients ventilated with a supraglottic device.

METHODS

We conducted an open prospective multicenter study with temporal clusters. OHCA patients treated by emergency nurses received either intermittent chest compressions with bag-valve mask ventilations (30:2 rhythm; BVM group); or continuous chest compressions with asynchronous ventilations by laryngeal tube (LT group). The primary endpoint was the CCF assessed using an accelerometer connected to the defibrillator. We also investigated the ease of use of the laryngeal tube.

RESULTS

Eighty-two patients were included (41 in each group); 68% were male and the median age was 68 (54-80) years. Patients and cardiac arrest characteristics did not differ between groups. The CCF was 75% (68-79%) in the LT group and 59% (51-68%) in the BVM group (p<0.01). LT insertion failed in nine out of 40 cases (23%). The median time of LT insertion was 26s (11-56 s). CCF was significantly lower when LT insertion failed (58% (48-74%) vs. 76% (72-80%) when LT insertion succeeded; p=0.01).

CONCLUSION

The use of the LT during OHCA increases the CCF when compared to standard BVM ventilation. However, the impact of LT use on mortality remains unclear.

The analysis of self and tutor assessment in the skill of basic life support (BLS) and endotracheal intubation: focused on the discrepancy in assessment

INTRODUCTION

This paper reports the results of a study of fourth year medical students that assessed whether assessments of basic life support (BLS) and intubation performance differ when assessed by the students themselves or by tutors. This information should be helpful for designing the contents of a complementary education core.

METHODS

Tutor assessments and student-assessments were conducted using a checklist and a fivepoint rating scale, and then compared. For the two skill performance tests, Resusci(®) Anne SkillGuide™ and Laerdal(®) Airway Management Trainer (Laerdal, Norway) devices were used. The check-lists used to evaluate students were based on International Liasion Committee on Resuscitation (ILCOR) guidelines and Korean Emergency Airway Management Society (KEAMS) tutor guidelines.

RESULTS

A total of 83 medical students participated in the study, intra-class correlation coefficient between tutor and student assessment were 0.542 (95% CI 0.371-0.678) in BLS and 0.693 (0.538-0.802). There were also no significant differences between self-assessments and tutor assessments based on the five-point. In BLS skill session, we found out that "maintenance of airway" and "palpating a carotid pulse" were the mostly missed parts. In the intubation skill, omitting the parts of 'securing the airway' while preparing for intubation, proper positioning of blade tip in the valleculae, and appropriate insertion of endotracheal tube were demonstrated.

CONCLUSION

We observed correlations between student self-assessments and tutor assessments for both BLS and intubation. Analyzing the discrepancies between self-assessment and tutor assessment will be helpful in focusing training on the steps that were omitted by students or during which students demonstrated incompetence.

[Modified two-rescuer resuscitation algorithm. Alternative for international missions of the German Armed Forces!]

BACKGROUND

The aim of this study was to examine whether it is possible to perform resuscitation according to the present European Resuscitation Council (ERC) guidelines with a modified algorithm in the case of special, e.g. military, circumstances. On international missions of the German Armed Forces a rescue team only consists of an emergency physician and a paramedic. As the German Armed Forces require the same means of medical aid for all soldiers on every type of mission worldwide the algorithm must meet the ERC requirements.

MATERIAL AND METHODS

In the study 20 medical teams specialized in resuscitation were examined. Of these teams 10 were from the German Armed Forces (the physician is a certified emergency physician) and 10 were civilian (the emergency physicians had up to 28 years experience). Each team was monitored as they performed resuscitation on a simulator for a period of 10 min. The patient's airway was secured by a laryngeal tube (LT) and over-the-head chest compressions were performed by the emergency physician. During resuscitation both team members held their position. In addition to comparing all results to the ERC guidelines both groups were analyzed separately and compared to each other.

RESULTS

The median time needed for securing the airway was 17 s without any differences between the 2 groups. In 75% of the cases the time needed for successfully securing the airway on the first attempt was less than the allowed 30 s. In 5 cases (25%) the teams did not manage to successfully install the LT during the first attempt (4 failed attempts were performed by civilian teams and 1 by the military emergency teams); however, all 5 teams were successful at the second attempt. In the cases where the placement of the LT was not successful at the first attempt the time required for the final and successful placement was nevertheless less than 40 s. During the 10 min resuscitation procedure the hands-off fraction was on average 22.4%. No differences between the two groups were noted concerning the hands-off time (133.5 s for the civilian teams and 134.5 s for the teams of the German Armed Forces). The frequency of chest compressions was above the required 100/min (for the civilian teams 110/min and for the teams of the German Armed Forces 116.5/min).

CONCLUSION

During military missions of the German Armed Forces there are no other options to perform resuscitation than by performing this procedure with only two rescuers. Using the algorithm in a modified way securing of the airway with an LT, the performance of over-the-head chest compressions and an effective resuscitation with advanced cardiac life support according to the ERC guidelines of 2005 are feasible even with 2 rescuers. Using the LT instead of endotracheal intubation to secure the airway particularly contributed to shortening the hands-off time.