Effect of Devices on Defibrillation Skill in the Objective Structured Clinical Examination; A Simulation Study

PURPOSE: Early defibrillation is essential for survival from ventricular fibrillation (VF). In Korea, assessment of clinical skills, including electrical defibrillation, has been part of the medical licensing examination since 2009. Although one defibrillator is used in the exam, various defibrillators are used in the real world. We wanted to know whether unfamiliar devices might affect defibrillation skill. METHODS: Our research was performed during conduct of the objective structured clinical examination (OSCE) for sixth grade medical students. Three different defibrillators were used for the test; CodeMaster, LiFEGAIN, and HEARTSTART MRx. CodeMaster was the defibrillator used for education and training. In the test room, VF was simulated by use of a simulator (SimMan(R)), and one of the three defibrillators was placed randomly. A checklist, where eight items among a total of 13 items were for device operation, was used for assessment of defibrillation skill. The written exam and clinical practice score for emergency medicine and defibrillation skill score were investigated. In addition, each operation time of device (turn-on, charge, and shock) was calculated with review of video resources containing the entire exam process. RESULTS: Among 65 students enrolled, 59 students were included for analysis. Students were divided according to CodeMaster (n=20), LiFEGAIN (n=15), and HEARTSTART MRx (n=24). No significant difference in the score on the written exam and clinical practice was observed among the groups. In addition, the scores for defibrillation skill and the time intervals did not differ among the groups. CONCLUSION: Unfamiliar devices may not affect defibrillation skill in medical students.

A Simulation Study for Quality of Chest Compression Provided by Health Personnel / 대한구급학회지

BACKGROUND: Effective chest compression may improve the return of spontaneous circulation and neurologic outcome in arrest victims. For fear of rescuer's fatigue, guidelines for cardiopulmonary resuscitation (CPR) recommended that chest compression (CC) should be switched every 2 minutes, but there is little evidence. We investigated whether health personnel could provide consistent quality of CC for 2 minutes. METHODS: We recruited prospectively health personnel working on one university hospital. On the day assigned randomly, CPR performance data was collected with use of CPR recording technology. Quality of CPR was calculated every 30 seconds interval. To identify the quality decay, we used repeated measure analysis of variance with SPSS 17.0 for analysis. RESULTS: We analyzed 8,485 CCs performed by 41 subjects. Total number of CC decayed between 90 to 120 seconds (51.6 +/- 3.3 to 50.8 +/- 3.5, p = 0.020) within recommended range. The ratio of correct depth CC decayed between 90 to 120 seconds, falling from 83.4 +/- 24.9% to 68.3 +/- 38.4% (p = 0.002). The ratio of low depth CC increased significantly over time (10.2 +/- 20.7% to 31.3 +/- 38.5%, p < 0.001). CONCLUSIONS: Health personnel may provide adequate number of CC for 2 minutes. But, the number of correct depth CC may decay between 90 to 120 seconds. Also the number of low depth CC may increase over time.

Quality and Rescuer's Fatigue with Repeated Chest Compression: A Simulation Study for In-hospital 2 Persons CPR

PURPOSE: The 2005 guidelines for cardiopulmonary resuscitation (CPR) caution that effective compression is essential (Class I) and chest compression (CC) by rescuers should be switched every 2 minutes to avoid rescuer's fatigue. It is controversial how long effective CC by a single individual can be provided. There are few reports about CPR quality, especially when rescuers perform CC for more than 10 minutes. The mean CPR period was about 30 minutes in Korea. We investigated the quality of CC and rescuer's fatigue after about 30 minutes. METHODS: From April 2009 to July 2009, health care providers (HCPs) were recruited into this study. The study simulated 2 person, in-hospital CPR. On the test day, which had been randomly assigned, each participant performed 7 CCs for about 30 minutes. The period of each CC was 2 minutes, and the period of each circulation check was 5 seconds. Participants' heart rates (HR) and visual analogue scale (VAS) scores for fatigue were obtained before and after each CC. Data for each 2 minutes CC was obtained with the use of Resusci Anne(R) with the Laerdal(R) PC skill reporting system. We used one-way repeated measures ANOVA for comparison of quality and fatigue of each CC and multiple linear regression for finding the predictors for correct CC. SPSS 17.0 was used for analysis. RESULTS: Among a total of 30 HCPs, data from 27 were analyzed. All participants were certified as a BLS provider and some were certified as BLS instructors. The rate of effective compression was 83.8+/-24.3%. Despite 2 min CC tasks were repeated alternatively for about 30 minutes, there were no differences in the number of correct CCs, depth and velocity of compression, and the number of incorrect CCs. CONCLUSION: During in-hospital CPR, HCPs may provide effective chest compressions on shifts with minimal effect of fatigue, even if they provide CC for 30 minutes.

Can Pulse Oximetry Plethysmography Waveform Amplitude in Respiratory Variations Predict fluid Responsiveness on Spontaneously Breathing Adult Shock Patients?

PURPOSE: It is difficult to predict volume responsiveness in hemodynamically unstable patients with spontaneous breathing activity. Our objective was to test whether the respiratory variations in pulse oximetry plethysmography (POP) waveform amplitude could predict fluid responsiveness to fluid resuscitation (FR) in spontaneously breathing adult shock patients. METHODS: We investigated 21 patients presenting with shock in the Emergency Room. We assessed hemodynamic status and calculated the respiratory variations in POP waveform amplitude before and after FR. Heart rate, blood pressures (MAP, SBP), maximal POP (POPmax), minimal POP (POPmin) and deltaPOP, defined as deltaPOP = (POPmax - POPmin) / ([POPmax + POPmin] / 2) were recorded. We measured hemodynamic parameters by doppler ultrasound, USCOM(R). RESULTS: Comparisons of hemodynamic parameters between before and after FR showed no significant difference in heart rate, but POP showed significant differences in changes in SBP, MAP, cardiac index, stroke volume index and respiratory variations. In response group(> or =15% in delta CI), the change in cardiac index, stroke volume index, and the respiratory variation in the POP were not significantly different. CONCLUSION: In spontaneously breathing patients with shock, we suggest that delta POP is not a reliable parameter in the prediction of fluid responsiveness.

Variations in Pulse Oximetry Plethysmographic Waveform Amplitude and Hemodynamic Assessment Induced by Passive Leg Raising in Spontaneously Breathing Adult Volunteers / 대한구급학회지

BACKGROUND: In hemodynamically unstable patients with spontaneous breathing activity, predicting volume responsivenss is a difficult challenge. Our objective was to test whether the respiratory changes in pulse oxymetry plethysmographic waveform amplitude (POP) and in stroke volume (deltaSV) could predict fluid responsiveness to passive leg raising (PLR) in normal volunteers. METHODS: We investigated 25 normal volunteers. We assessed hemodynamic status (HR, SBP, MAP, CI and SVI) and calculated the respiratory variation in pulse oximetry plethysmographic waveform amplitude at supine and after PLR. We attached a pulse oximeter of 25 spontaneously breathing volunteers as several time points: after 1 min and 5 min in supine position and during PLR at 60degrees. Heart rate, non-invasive blood pressures (mean arterial pressure, systolic blood pressure), maximal POP (POPmax), minimal POP (POPmin) and deltaPOP defined as (POPmax-POPmin)/[(POPmax+POPmin)/2] were recorded using monitor. RESULTS: Comparing to supine and PLR, systolic blood pressure and mean arterial pressure were not different, but the change in cardiac index, stroke volume and respiratory variation in POP were significant different. In response group (> or =10% in deltaCI), the change in cardiac index, stroke volume and respiratory variation in POP were significant greater. CONCLUSION: PLR induces a significant decrement of variation in POP amplitude among spontaneouely breathing volunteers. We suppose that the changes in stroke volume and the respiratory variation in pulse oximetry plethysmographic waveform amplitude induced by PLR predict fluid responsiveness in spontaneous breathing patients.

Second-tier Instruction of Cardiopulmonary Resuscitation by CPR Anytime(R) Trainees

PURPOSE: CPR Anytime(R), a self-instructional video program, has gained popularity amongst CPR instructors for training non-healthcare providers. This instructional kit enables second-tier instruction. The purpose of this study is to determine the status of second-tier instruction CPR by CPR Anytime(R) trainees. METHODS: Questionnaires were sent to 606 CPR Anytime(R) trainees from 12 BLS training sites. The training period was from October 2006 to July 2007. Questionnaires included provider's basic information, post-course self exercise, amount of second-tier instruction, and multiplier status. RESULTS: The response rate of the questionnaire was 53.6%(325). The mean age was 20.4+/-10.3 years old. The professions of respondents were as follows: students (76.3%), office workers(13.2%), teachers(4.4%), and service providers(1.9%). The post-course self exercise rate was 49% with three fourths of those completing the exercises using both the DVD and MiniAnne(R). Second-tier instruction tools use rates(48%) were as follows: DVD and manikin(35%), manikin only(9%), verbal only(2%), and DVD only(1%). The total multiplier effect was 1.77(575/ 325) with the multiplier effect of teachers significantly higher than others. CONCLUSION: This study found that 48% of CPR Anytime(R) providers perform second-tier instruction to family and friends. Amongst them, the total multiplier effect was 1.77 (575/325).

Intermediate Myasthenia Syndrome Following Organophosphate Intoxication

BACKGROUND: Intermediate myasthenia syndrome(IMS) is thought to have clinical importance because it may cause sudden respiratory failure during the recovery phase of a cholinergic crisis of organophosphate poisoning. We designed this study to identify the prevalence, the inducing agent, clinical predictor, and the proposed treatment of IMS. METHODS: Patients who had admitted with the diagnosis of acute organophosphate poisoning from 1992 to 1998 at two teaching hospitals were enrolled in this study. We selected the cases of IMS based on a review of medical records using modified He's criteria. RESULTS: Twelve(12) out of 110 patients with acute organophosphate poisoning were diagnosed for a prevalence at 10.9%. The drug inducing IMS were identified as dichlorvos, fenthion, EPN, methidathion, and phosphamidon. The occurrence of IMS was not related to either the initial treatment with atropine and pralidoxime, or the level of serum cholinesterase. Complications were pneumonia, sepsis, pancreatitis, and pseudomembranous colitis, etc. Eleven(11) patients were discharged without sequelae, and one patient was discharged as a hopeless care. CONCLUSION: This study suggests that IMS is not rare, so close observation is required to detect IMS in organophosphate-poisoning patients. Also, more studies are required to find predictors and treatments.

A Clinical Experience on Pneumomediastinum: Report of 2 cases

Pneumomediastinum is a relatively uncommon, infrequently reported entity, In the evaluation of these entity, it is important to exclude pathological causes, including Boerhaave's syndrome which carries a high mortality. Spontaneous pneumomediastinum is related to excessive intraalveolar pressure leading to rupture of perivascular alveoli in the setting of a Valsalva maneuver without communication to gut material. So, it has a benign self-limited course and rarely requires medical intervention. On the contrary, secondary pneumomediastinum caused by instrumental, traumatic, and spontaneous perforation of esophagus. Although the prognosis have been improved since the advent of broad-spectrum antibiotics and nutritional support, pneumomediastinum due to esophageal perforation still has a high morbidity and mortality. The most important prognostic factor is the time interval between perforation and initiation of therapy, and an awareness and a high clinical suspicion is critical in the early diagnosis and treatment. Recently, we have experienced 2 cases of pneumomediastinum, one case was spontaneous pneumomediastinum and the other may be caused by instrumental esophageal perforation. We report the clinical course of the patients with a current literature review.