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.