Bicycle helmet ventilation and comfort angle dependence

Five modern bicycle helmets were studied to elucidate some of the variations in ventilation performance, using both a heated manikin headform and human subjects (n=7). Wind speed and head angle were varied to test their influence on the measured steady-state heat exchange (cooling power) in the skull section of the headform. The cooling power transmitted by the helmets varied from about 60% to over 90% of that of the nude headform, illustrating the range of present manufacturer designs. Angling the head forward by 30° was found to provide better cooling power to the skull (up to 25%) for three of the helmets and almost equal cooling power in the remaining two cases. Comparisons of skull ventilation at these angles with human subjects strongly supported the headform results.     

Laryngoscopic versus intubating LMA guided tracheal intubation by novice users--a manikin study

AIM OF THE STUDY: Airway control is a potentially lifesaving procedure but tracheal intubation by direct laryngoscopy is difficult. This pilot study was conducted to determine whether tracheal intubation was more rapid and the success rate higher using an intubating laryngeal mask airway. MATERIAL AND METHODS: The success rates of 119 medical students without prior airway management experience in ventilating and then intubating the trachea of a Laerdal Airway Management Trainer with two different methods were compared. The methods were bag-mask ventilation (BM-V) followed by laryngoscopic intubation (LG-TI), and intubating laryngeal mask ventilation (ILMA-V) followed by ILMA-guided tracheal intubation (ILMA-TI). After an introductory lecture and demonstration, each student was allowed three attempts to intubate using each method in random order. RESULTS: All participants were successful with BM-V and ILMA-V on the first attempt. Laryngoscopic tracheal intubation was achieved by 60 (50.4%), 31 (26.1%) and 12 (10.1%) participants on the first, second and third attempt, respectively, while 16 (13.4%) failed in all three attempts. In the ILMA-TI group, 107 (90.0%), 10 (8.4%) and 2 (1.6%) succeeded on the first, second and third attempt, respectively. None failed. The intergroup difference is highly significant (p<0.001). Male participants were more successful with LG-TI than female (p<0.01), but not with ILMA-TI. CONCLUSION: Laryngoscopic orotracheal intubation is difficult for the untrained, but all participants were successful with ILMA-TI. These data suggest that alternative devices such as the ILMA should be included in the medical school curriculum for airway management.     

Alternating providers during continuous chest compressions for cardiac arrest: Every minute or every two minutes?

Studies have shown that the quality of chest compressions for cardiac arrest decreases markedly after only a brief time. This is thought to be an important contributor to an adverse outcome of resuscitation, which has led to recommendations to alternate chest compression providers. This study compared alternating rescuers every 1 min versus every 2 min in a manikin simulation. Forty pairs of rescuers were randomly assigned to either scenario. The main outcome measure was the number of effective compressions. The results were analysed using one-way analysis of variance. Over the full 8 min, no significant difference was found in the number of effective chest compressions (p = 0.707). Furthermore, no significant difference was found when comparing each 2 min block. An explanation for this may be that the compressions lost due to fatigue in the 2 min scenario are approximately offset by compressions lost due to the practicalities of changing over. Power calculations with these results show that an unfeasibly large number of scenarios would be needed to definitively demonstrate the superiority of one of the scenarios. It seems reasonable to alternate chest compression providers every 2 min, to prevent the loss of effective compressions due to fatigue and to minimise interruptions of chest compressions. The ideal time to do this would be during the rhythm and pulse check as dictated by current guidelines.     

Animation-assisted CPRII program as a reminder tool in achieving effective one-person-CPR performance

Objective

The objective of this study is to compare the skill retention of two groups of lay persons, six months after their last CPR training. The intervention group was provided with animation-assisted CPRII (AA-CPRII) instruction on their cellular phones, and the control group had nothing but what they learned from their previous training.

Methods

This study was a single blind randomized controlled trial. The participants’ last CPR trainings were held at least six months ago. We revised our CPR animation for on-site CPR instruction content emphasizing importance of chest compression. Participants were randomized into two groups, the AA-CPRII group (n = 42) and the control group (n = 38). Both groups performed three cycles of CPR and their performances were video recorded. These video clips were assessed by three evaluators using a checklist. The psychomotor skills were evaluated using the Resusci^®Anne SkillReporter™.

Results

Using the 30-point scoring checklist, the AA-CPRII group had a significantly better score compared to the control group (p < 0.001). Psychomotor skills evaluated with the AA-CPRII group demonstrated better performance in hand positioning (p = 0.025), compression depth (p = 0.035) and compression rate (p < 0.001) than the control group.

Conclusion

The AA-CPRII group resulted in better checklist scores, including chest compression rate, depth and hand positioning. Animation-assisted CPR could be used as a reminder tool in achieving effective one-person-CPR performance. By installing the CPR instruction on cellular phones and having taught them CPR with it during the training enabled participants to perform better CPR.     

The efficacy of straddling external chest compression on a moving stretcher

Objective

To evaluate the efficacy of straddling external chest compression performed on moving stretchers.

Methods

The study was a prospective, randomized, cross-over study on a manikin performed at a university hospital. Twenty subjects were selected from the 40 graduates using random numbers to participate in the study. Participants were randomized to either performing standard or straddling external chest compression followed by the other technique 7 days later. The compression variables and time to first compression were recorded.

Results

Twenty subjects (12 males and 8 females) took part in the study. There were no differences between the standard and straddling external chest compression for the compression rate, effective compression percentage and compression depth. There was no difference between the standard external chest compression and straddling external chest compression for incorrect hand position and incomplete release compression. Time to first compression during straddling external chest compression (10.31 ± 1.65 s) was greater than that during standard external chest compression (2.74 ± 0.40 s) (P < 0.001).

Conclusions

The quality of straddling external chest compression performed on a moving stretcher was as effective as standard external chest compression performed on the floor. By performing straddling external chest compression, time for transporting victims to the emergency department to get advanced life support may be shortened.     

Acquisition and retention of basic life support skills in an untrained population using a personal resuscitation manikin and video self-instruction (VSI)

Background

Video-based self-instruction (VSI) with a 24-min DVD and a personal resuscitation manikin solves some of the barriers associated with traditional basic life support (BLS) courses. No accurate assessment of the actual improvement in skills after attending a VSI course has been determined, and in this study we assess the skill improvement in laypersons undergoing VSI.

Methods

The BLS skills of 68 untrained laypersons (high school students, their teachers and persons excluded from mainstream society) were assessed using the Laerdal ResusciAnne and PC Skill Reporting System 2.0 in a 3 min test. A total score (12-48 points) was calculated and 12 different variables were recorded. The participants attended a 24-min VSI course (MiniAnne, Laerdal) and took home the DVD and manikin for optional subsequent self-training. We repeated the test 3½-4 months later.

Results

There was a significant increase in the total score (p < 0.0001) from 26.5 to 34 points. The participants performed significantly better in checking responsiveness, opening the airway, checking for respiration and using the correct compression/ventilation ratio (all p-values < 0.001). The compression depth improved from 38 mm to 49.5 mm and the total number of compressions increased from 67 to 141. The ventilation volume and the total number of ventilations increased, and total “hands-off” time decreased from 120.5 s to 85 s.

Conclusions

Untrained laypersons attending a 24 min DVD-based BLS course have a significantly improved BLS performance after 3½-4 months compared to pre-test skill performance. Especially the total number of compressions improved and the hands-off time decreased.     

The history of medical simulation

The historical roots of simulation might be described with the broadest definition of medical simulation: "an imitation of some real thing, state of affairs, or process" for the practice of skills, problem solving, and judgment. From the first "blue box" flight simulator to the military's impetus in the transfer of modeling and simulation technology to medicine, worldwide acceptance of simulation training is growing. Large collaborative simulation centers support the expectation of increases in multidisciplinary, interprofessional, and multimodal simulation training. Virtual worlds, both immersive and Web-based, are at the frontier of innovation in medical education.