Hyunggoo Kang

The use of dual accelerometers improves measurement of chest compression depth

BACKGROUND Chest compression (CC) feedback devices are used to perform CC measurements effectively and accurately on patients in hospital beds. However, these devices do not take account of the compression of the mattress, which results in overestimation of CC depth. In this study, we propose a new method using two accelerometers to overcome this limitation and thus measure compression depth more accurately when performing cardiopulmonary resuscitation (CPR) on patients. METHOD One accelerometer was placed on the manikins sternum (a1), and the other between the manikins back and the mattress (a2). The compression depth was calculated by integrating the acceleration twice using a digital signal processing technique. We compared CC depth from dual accelerometers and single accelerometer (a1) on the foam and inflated air mattress with eight CPR providers. RESULT When CC was done on a manikin lying on the floor, there was no significant difference between measurement techniques (p>0.05). When CC was done on a manikin lying on the foam and inflated air mattress supporting system, our method significantly improved the estimation of CC depth, irrespective of the presence or absence of a backboard (p<0.001). CONCLUSION Measuring CC depth using two accelerometers is more effective than using one in increasing the accuracy of CC depth estimation when CPR is performed on the foam and inflated air mattress, regardless of the presence or absence of a backboard.

Endotracheal intubation using a GlideScope video laryngoscope by emergency physicians: a multicentre analysis of 345 attempts in adult patients

Objective To investigate the use and success rates of the GlideScope (GVL) by emergency physicians (EPs) during the initial two years after its introduction. Methods We performed an observational study using registry data of five emergency departments. The success rates in adult patients were evaluated and compared with those of conventional laryngoscope (CL). Results The GVL was used in 345 (10.7%) of 3233 intubation attempts by EPs. The overall success rate of the GVL was not higher than a CL (79.1% vs 77.6%, p=0.538). The success rate for the patients with difficult airway was higher in the GVL than a CL (80.0% vs 50.4%, p<0.001). Conclusion The GVL was not used frequently by EPs during the initial two years after its introduction. Although the GVL provides a better glottic view, the overall success rates were similar to a CL. The GVL may be useful in patients with difficult airway.

Direct versus Video Laryngoscopic Intubation by Novice Prehospital Intubators with and without Chest Compressions: A Pilot Manikin Study

Abstract Objectives. To evaluate whether chest compressions affect the time taken for intubation (TTI) using the Macintosh laryngoscope and two portable video laryngoscopes (VLs) (GlideScope Ranger and Airway Scope) when used by novice prehospital caregivers, and to compare the TTIs and rates of successful intubation among the three laryngoscopes with and without chest compressions in a manikin model. Methods. This was a pilot randomized crossover study. Twenty paramedic students and paramedics who had no clinical experience with tracheal intubation and had never used any of two VLs participated in the study. After a one-hour training session for the VLs, participants performed intubations on a Laerdal Resusci Anne Simulator placed on the floor. Each paramedic used all three laryngoscopes, with the order of usage being randomly assigned. The TTIs and rates of successful intubation among the three laryngoscopes, with and without ongoing chest compressions, were compared. Results. The difference between the TTIs using each laryngoscope with and without chest compressions was not significant (Macintosh: 2.99 sec, p == 0.06; GlideScope Ranger: 2.04 sec, p == 0.11; and Airway Scope: 0.91 sec, p == 0.10). The median TTI using the Airway Scope (15.46 sec) was significantly shorter than those for the Macintosh (24.14 sec) and the GlideScope Ranger (24.12 sec) during chest compressions (p == 0.028 and p == 0.004, respectively). There were no significant differences in the rates of successful intubation among the three laryngoscopes on each condition (without chest compressions, p == 0.15; with chest compressions, p == 0.27), but the cumulative success rates related to the TTI were significantly greater with the Airway Scope than with the other devices in both conditions. Conclusion. In this pilot study, chest compressions did not significantly affect the TTI using the Macintosh laryngoscope and two portable VLs when used by novice prehospital caregivers in the manikin model on the floor. Considering the fairly short training time, two portable VLs may be potentially useful adjuncts for tracheal intubation during chest compressions for novice prehospital caregivers. Further studies are required to validate whether these findings are clinically relevant. Key words: chest compression; tracheal intubation; video laryngoscope

Tracheal intubation using Macintosh and 2 video laryngoscopes with and without chest compressions

PURPOSE The aim of the study was to compare the time taken for intubation (TTI) using the Macintosh and 2 video laryngoscopes (VLs) (GlideScope [GVL]; Saturn Biomedical System, Burnaby, British Columbia, Canada, and Airway Scope [AWS]; Pentax, Tokyo, Japan) with and without chest compressions by experienced intubators in a mannequin model. METHODS This was a randomized crossover study. Twenty-two experienced physicians who have limited experience in the VLs participated in the study. The TTI using 3 laryngoscopes with and without compressions were compared. RESULTS Median TTI difference between 2 conditions was only significant in the AWS (1.64 seconds; P = .01). There were no significant differences in the TTI between the Macintosh and the GVL or the AWS during compressions. CONCLUSION In a mannequin model, the Macintosh or the GVL was not affected by chest compressions. The TTI using the AWS was delayed by compressions but not clinically significant. Considering the lack of experience, 2 VLs may be useful adjuncts for intubation by experienced intubators during chest compressions.

What factors affect the success rate of the first attempt at endotracheal intubation in emergency departments

Study objective This study aimed to determine the factors associated with successful endotracheal intubation (ETI) on the first-attempt in an emergency department. Method We studied all of the ETI data at two urban emergency departments over a 5-year period. We assessed the intubators specialty and training level, intubation method, device used, predicted airway difficulty and cause of ETIs. Univariate and multivariate logistic regression models were used to identify factors affecting the first-attempt success (FAS) of ETI in emergency departments. Results A total of 1478 adult ETIs were analysed. A multivariate logistic analysis revealed that factors such as a non-difficult airway (OR=5.11; 95% CI 3.38 to 7.72), senior physicians (2nd-year to 4th-year resident and attending physicians) (OR=2.39; 95% CI 1.61 to 3.55) and the rapid sequence intubation/induction (RSI) method (OR=2.06; 95% CI 1.04 to 3.03) had significant associations with the FAS for emergency medicine (EM) physicians. For non-EM physicians, however, a non-difficult airway was the only independent predictor of FAS (OR=3.10; 95% CI 1.82 to 5.28). Conclusions The predicted airway difficulty was the major factor associated with FAS in emergency department ETI on adults regardless of intubators specialty. Especially in EM physician group, level of training and using of RSI also affecting on first–attempt success. The overall ETI success rate on first attempt was 80.1%, but EM physicians had success rate of 87.3%. Systematic technical and non-technical airway skill training focused on RSI and continuous quality control and ETI recording could help non-EM physicians increase their FAS rate.

An application of the learning curve–cumulative summation test to evaluate training for endotracheal intubation in emergency medicine

Objective The learning curve–cumulative summation (LC-CUSUM) test allows for quantitative and individual assessments of the learning process. In this study, we evaluated the process of skill acquisition for performing endotracheal intubation (ETI) in three emergency medicine (EM) residents over a 2 year period in their first 2 years of their EM residency. Methods We evaluated 342 ETI cases performed by three EM residents using the LC-CUSUM test according to their rate of success or failure of ETI. A 90% success rate (SR) was chosen to define adequate performance and an SR of 80% was considered inadequate. After the learning phase, the standard CUSUM test was applied to ensure that performance was maintained. Results The mean number of ETI cases required to reach the predefined level of performance was 74.7 (95% CI 62.0 to 87.3). CUSUM tests confirmed that performance was maintained after the learning phase. Conclusions By using the LC-CUSUM test, we were able to quantitatively monitor the acquisition of the skill of ETI by EM residents. The LC-CUSUM could be useful for monitoring the learning process for the training of airway management in the practice of EM.

Effects of script-based role play in cardiopulmonary resuscitation team training

Background The purpose of this study is to compare the cardiopulmonary resuscitation (CPR) team dynamics and performance between a conventional simulation training group and a script-based training group. Methods This was a prospective randomised controlled trial of educational intervention for CPR team training. Fourteen teams, each consisting of five members, were recruited. The conventional group (C) received training using a didactic lecture and simulation with debriefing, while the script group (S) received training using a resuscitation script. The team activity was evaluated with checklists both before and after 1 week of training. The videotaped simulated resuscitation events were compared in terms of team dynamics and performance aspects. Results Both groups showed significantly higher leadership scores after training (C: 58.2±9.2 vs 67.2±9.5, p=0.007; S: 57.9±8.1 vs 65.4±12.1, p=0.034). However, there were no significant improvements in performance scores in either group after training. There were no differences in the score improvement after training between the two groups in dynamics (C: 9.1±12.6 vs S: 7.4±13.7, p=0.715), performance (C: 5.5±11.4 vs S: 4.7±9.6, p=0.838) and total scores (C: 14.6±20.1 vs S: 12.2±19.5, p=0.726). Conclusion Script-based CPR team training resulted in comparable improvements in team dynamics scores compared with conventional simulation training. Resuscitation scripts may be used as an adjunct for CPR team training.

GlideScope video laryngoscopy versus direct laryngoscopy in the emergency department: a propensity score-matched analysis

Objective To evaluate whether the use of a GlideScope video laryngoscope (GVL) improves first-attempt intubation success compared with the Macintosh laryngoscope (MAC) in the emergency department (ED). Design A propensity score-matched analysis of data from a prospective multicentre ED airway registry—the Korean Emergency Airway Management Registry (KEAMR). Setting 4 academic EDs located in a metropolitan city and a province in South Korea. Participants A total of 4041 adult patients without cardiac arrest who underwent emergency intubation from January 2007 to December 2010. Outcome measures The primary and secondary outcomes were successful first intubation attempt and intubation failure, respectively. To reduce the selection bias and potential confounding effects, we rigorously adjusted for the baseline differences between two groups using a propensity score matching. Results Of the 4041 eligible patients, a GVL was initially used in 540 patients (13.4%). Using 1:2 propensity score matching, 363 and 726 patients were assigned to the GVL and MAC groups, respectively. The adjusted relative risks (95% CIs) for the first-attempt success rates with a GVL compared with a MAC were 0.76 (0.56 to 1.04; p=0.084) and the respective intubation failure rates 1.03(0.99 to 1.07; p=0.157). Regarding the subgroups, the first-attempt success of the senior residents and attending physicians was lower with the GVL (0.47 (0.23 to 0.98), p=0.043). In the patients with slight intubation difficulty, the first-attempt success was lower (0.60 (0.41 to 0.88), p=0.008) and the intubation failure was higher with the GVL (1.07 (1.02 to 1.13), p=0.008). Conclusions In this propensity score-matched analysis of data from a prospective multicentre ED airway registry, the overall first-attempt intubation success and failure rates did not differ significantly between GVL and MAC in the ED setting. Further randomised controlled trials are needed to confirm our findings.

Videographic Analysis of Glottic View With Increasing Cricoid Pressure Force

STUDY OBJECTIVE Cricoid pressure may negatively affect laryngeal view and compromise airway patency, according to previous studies of direct laryngoscopy, endoscopy, and radiologic imaging. In this study, we assess the effect of cricoid pressure on laryngeal view with a video laryngoscope, the Pentax-AWS. METHODS This cross-sectional survey involved 50 American Society of Anesthesiologists status I and II patients who were scheduled to undergo elective surgery. The force measurement sensor for cricoid pressure and the video recording system using a Pentax-AWS video laryngoscope were newly developed by the authors. After force and video were recorded simultaneously, 11 still images were selected per 5-N (Newton; 1 N = 1 kg·m·s(-2)) increments, from 0 N to 50 N for each patient. The effect of cricoid pressure was assessed by relative percentage compared with the number of pixels on an image at 0 N. RESULTS Compared with zero cricoid pressure, the median percentage of glottic view visible was 89.5% (interquartile range [IQR] 64.2% to 117.1%) at 10 N, 83.2% (IQR 44.2% to 113.7%) at 20 N, 76.4% (IQR 34.1% to 109.1%) at 30 N, 51.0% (IQR 21.8% to 104.2%) at 40 N, and 47.6% (IQR 15.2% to 107.4%) at 50 N. The number of subjects who showed unworsened views was 20 (40%) at 10 N, 17 (34%) at 20 and 30 N, and 13 (26%) at 40 and 50 N. CONCLUSION Cricoid pressure application with increasing force resulted in a worse glottic view, as examined with the Pentax-AWS Video laryngoscope. There is much individual difference in the degree of change, even with the same force. Clinicians should be aware that cricoid pressure affects laryngeal view with the Pentax-AWS and likely other video laryngoscopes.

A Randomized Comparison Simulating Face to Face Endotracheal Intubation of Pentax Airway Scope, C-MAC Video Laryngoscope, Glidescope Video Laryngoscope, and Macintosh Laryngoscope.

Objectives. Early airway management is very important for severely ill patients. This study aimed to investigate the efficacy of face to face intubation in four different types of laryngoscopes (Macintosh laryngoscope, Pentax airway scope (AWS), Glidescope video laryngoscope (GVL), and C-MAC video laryngoscope (C-MAC)). Method. Ninety-five nurses and emergency medical technicians were trained to use the AWS, C-MAC, GVL and Macintosh laryngoscope with standard airway trainer manikin and face to face intubation. We compared VCET (vocal cord exposure time), tube pass time, 1st ventilation time, VCET to tube pass time, tube pass time to 1st ventilation time, and POGO (percentage of glottis opening) score. In addition, we compared success rate according to the number of attempts and complications. Result. VCET was similar among all laryngoscopes and POGO score was higher in AWS. AWS and Macintosh blade were faster than GVL and C-MAC in total intubation time. Face to face intubation success rate was lower in GVL than other laryngoscopes. Conclusion. AWS and Macintosh were favorable laryngoscopes in face to face intubation. GVL had disadvantage performing face to face intubation.