Lars Wik

Intravenous Drug Administration During Out-of-Hospital Cardiac Arrest: A Randomized Trial

CONTEXT Intravenous access and drug administration are included in advanced cardiac life support (ACLS) guidelines despite a lack of evidence for improved outcomes. Epinephrine was an independent predictor of poor outcome in a large epidemiological study, possibly due to toxicity of the drug or cardiopulmonary resuscitation (CPR) interruptions secondary to establishing an intravenous line and drug administration. OBJECTIVE To determine whether removing intravenous drug administration from an ACLS protocol would improve survival to hospital discharge after out-of-hospital cardiac arrest. DESIGN, SETTING, AND PATIENTS Prospective, randomized controlled trial of consecutive adult patients with out-of-hospital nontraumatic cardiac arrest treated within the emergency medical service system in Oslo, Norway, between May 1, 2003, and April 28, 2008. INTERVENTIONS Advanced cardiac life support with intravenous drug administration or ACLS without access to intravenous drug administration. MAIN OUTCOME MEASURES The primary outcome was survival to hospital discharge. The secondary outcomes were 1-year survival, survival with favorable neurological outcome, hospital admission with return of spontaneous circulation, and quality of CPR (chest compression rate, pauses, and ventilation rate). RESULTS Of 1183 patients for whom resuscitation was attempted, 851 were included; 418 patients were in the ACLS with intravenous drug administration group and 433 were in the ACLS with no access to intravenous drug administration group. The rate of survival to hospital discharge was 10.5% for the intravenous drug administration group and 9.2% for the no intravenous drug administration group (P = .61), 32% vs 21%, respectively, (P<.001) for hospital admission with return of spontaneous circulation, 9.8% vs 8.1% (P = .45) for survival with favorable neurological outcome, and 10% vs 8% (P = .53) for survival at 1 year. The quality of CPR was comparable and within guideline recommendations for both groups. After adjustment for ventricular fibrillation, response interval, witnessed arrest, or arrest in a public location, there was no significant difference in survival to hospital discharge for the intravenous group vs the no intravenous group (adjusted odds ratio, 1.15; 95% confidence interval, 0.69-1.91). CONCLUSION Compared with patients who received ACLS without intravenous drug administration following out-of-hospital cardiac arrest, patients with intravenous access and drug administration had higher rates of short-term survival with no statistically significant improvement in survival to hospital discharge, quality of CPR, or long-term survival. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00121524.

Effects of Cardiopulmonary Resuscitation on Predictors of Ventricular Fibrillation Defibrillation Success During Out-of-Hospital Cardiac Arrest

Background—Early defibrillation is considered the most important factor for restoring spontaneous circulation in cardiac arrest patients with ventricular fibrillation. Recent studies have shown that, after prolonged ventricular fibrillation, the rates of return of spontaneous circulation (ROSC) and survival are improved if defibrillation is delayed so that CPR can be given first. To examine whether CPR improves myocardial readiness for defibrillation, we analyzed whether CPR causes changes in predictors of defibrillation success calculated from the ventricular fibrillation waveform. Methods and Results—ECG recordings were retrieved for 105 patients from an original study of 200 patients receiving CPR or defibrillation first. Altogether, 267 CPR sequences from 77 patients were identified on which the effect of CPR could be evaluated. Five predictors of ROSC (spectral flatness measure, energy, centroid frequency, amplitude spectrum relationship, and estimated probability of ROSC) were determined from a spectral analysis of the ventricular fibrillation waveform immediately before and immediately after each of the 267 sequences. CPR increased spectral flatness measure, centroid frequency, and amplitude spectrum relationship (P <0.05, P <0.001, P <0.01). In an analysis of the effect of the duration of CPR, the probability of ROSC and amplitude spectrum relationship showed a positive change for CPR sequences lasting >3 minutes (P <0.001, P <0.05). Conclusions—During resuscitation from ventricular fibrillation, changes in the predictors calculated from the ventricular fibrillation waveform indicated a positive effect of CPR on the myocardium.

Retention of basic life support skills 6 months after training with an automated voice advisory manikin system without instructor involvement

AIM To evaluate the retention of skills 6 months after training in ventilation and chest compressions (CPR) on a manikin with computer based on-line voice advisory feedback and the possible effects of initial overtraining. METHODS Thirty five volunteers had 20 min provisional CPR training on a manikin with computer based voice advisory feedback but without an instructor. The appropriate feedback was taken from a pre-recorded list depending on performance measured by the manikin--computer system versus set limits for ventilation and compression variables. One group in addition was randomised to receive 10 similar 3 min training sessions during 1 week in the following month (overtrained group). All ventilation and compression variables were measured without feedback before and after the initial training session, with feedback immediately thereafter, and both without and with feedback 6 months after the initial training session. RESULTS The initial training improved all variables. Compressions with correct depth increased from a mean of 33 to 77%, and correct inflations from a mean of 9 to 58%. After 6 months, the results for the controls were not significantly different from pre-training, except for a higher of correct inflations (18%), while the overtrained group had better retention of skills including the correct compression depth (mean 61%) and inflations (mean 42%). When verbal feedback was added both the compressions and ventilations immediately improved both when tested immediately and 6 months after the initial training session. CONCLUSIONS The computer-based voice advisory manikin (VAM) feedback system can improve immediate performance of basic life support (BLS) skills, with better long-term retention with overtraining.

Manual vs. integrated automatic load-distributing band CPR with equal survival after out of hospital cardiac arrest. The randomized CIRC trial

OBJECTIVE To compare integrated automated load distributing band CPR (iA-CPR) with high-quality manual CPR (M-CPR) to determine equivalence, superiority, or inferiority in survival to hospital discharge. METHODS Between March 5, 2009 and January 11, 2011 a randomized, unblinded, controlled group sequential trial of adult out-of-hospital cardiac arrests of presumed cardiac origin was conducted at three US and two European sites. After EMS providers initiated manual compressions patients were randomized to receive either iA-CPR or M-CPR. Patient follow-up was until all patients were discharged alive or died. The primary outcome, survival to hospital discharge, was analyzed adjusting for covariates, (age, witnessed arrest, initial cardiac rhythm, enrollment site) and interim analyses. CPR quality and protocol adherence were monitored (CPR fraction) electronically throughout the trial. RESULTS Of 4753 randomized patients, 522 (11.0%) met post enrollment exclusion criteria. Therefore, 2099 (49.6%) received iA-CPR and 2132 (50.4%) M-CPR. Sustained ROSC (emergency department admittance), 24h survival and hospital discharge (unknown for 12 cases) for iA-CPR compared to M-CPR were 600 (28.6%) vs. 689 (32.3%), 456 (21.8%) vs. 532 (25.0%), 196 (9.4%) vs. 233 (11.0%) patients, respectively. The adjusted odds ratio of survival to hospital discharge for iA-CPR compared to M-CPR, was 1.06 (95% CI 0.83-1.37), meeting the criteria for equivalence. The 20 min CPR fraction was 80.4% for iA-CPR and 80.2% for M-CPR. CONCLUSION Compared to high-quality M-CPR, iA-CPR resulted in statistically equivalent survival to hospital discharge.

An automated voice advisory manikin system for training in basic life support without an instructor. A novel approach to CPR training

Twenty-four paramedic students with previous basic life support training were randomised, performing cardiopulmonary resuscitation (CPR) on a manikin for 3 min without any feedback followed by 3 min of CPR with audio feedback from the manikin after a 2-min break, or vice versa. A computer recorded information on timing, ventilation flow rates and volumes and all movements of the sternum of the manikin. The software allowed acceptable limits to be set for all ventilation and compression/release variables giving appropriate on-line audio feedback according to these settings from among approximately 40 pre-recorded messages. Students who started without feedback significantly improved after feedback in terms of the median percentage of correct inflations (from 2 to 64%), with most inflations being rapid before feedback (94%), compressions of correct depth (from 32 to 92%), and the duration of compressions in the duty cycle (from 41 to 44%). There were no problems with the median compression rate, sternal release during decompressions, or the hand position, even before feedback. There were no significant differences in any variables with and without feedback for the students who started with feedback, or between the audio feedback periods of the two groups. It is concluded that this automated voice advisory manikin system, a novel approach to basic CPR training, caused an immediate improvement in the skills performance of paramedic students.

Improving outcome after out-of-hospital cardiac arrest by strengthening weak links of the local Chain of Survival; quality of advanced life support and post-resuscitation care

BACKGROUND Survival after out-of-hospital cardiac arrest (OHCA) depends on a well functioning Chain of Survival. We wanted to assess if targeted attempts to strengthen the weak links of our local chain; quality of advanced life support (ALS) and post-resuscitation care, would improve outcome. MATERIALS AND METHODS Utstein data from all OHCAs in Oslo during three distinct 2-year time periods 1996-1998, 2001-2003 and 2004-2005 were collected. Before the second period the local ALS guidelines changed with increased focus on good quality chest compressions with minimal pauses, while standardized post-resuscitation care including goal directed therapy with therapeutic hypothermia and percutaneous coronary intervention was added in the third period. Additional a priori sub-group analyses of arrests with cardiac aetiology as well as bystander witnessed ventricular fibrillation/tachycardia (VF/VT) arrests with cardiac aetiology were performed. RESULTS ALS was attempted in 454, 449, and 417 patients with OHCA in the first, second and last time period, respectively. From the first to the third period VF/VT arrests declined (40% vs. 33%, p=0.039) and fewer arrests were witnessed (80% vs. 72%, p=0.022) and response intervals increased (7+/-4 to 9+/-4 min, p<0.001). Overall survival increased from 7% (first period) to 13% (last period), p=0.002, and survival in the sub-group of bystander witnessed VF/VT arrests with cardiac aetiology increased from 15% (first period) to 35% (last period), p=0.001. CONCLUSIONS Survival after OHCA was increased after improving weak links of our local Chain of Survival, quality of ALS and post-resuscitation care.

Dispatcher-assisted cardiopulmonary resuscitation. An evaluation of efficacy amongst elderly

Bystander cardiopulmonary resuscitation (CPR) increases survival rates. The largest group of cardiac arrest patients are men over the age of 60 in the home, and the most probable potential CPR provider is an older woman who is not likely to have received CPR training. One method to increase the percentage of bystander-initiated CPR in this setting is for CPR instruction to be provided by nurse dispatchers via telephone. Two male and 18 female volunteers with a median age of 78 years and no previous CPR experience performed 9 min of telephone assisted CPR on a manikin. They were randomised to receive telephone instructions in chest compressions alone or standard CPR including mouth-to-mouth ventilation. Variables were registered by a recording manikin, visual observations, and video and audiotape recordings. The median period from dispatcher contact until continuous CPR was significantly longer for standard instructions than for compression only, 4.9 versus 3.4 min, and fewer chest compressions were provided during the 9 min test period, median 124 versus 334 compressions. In both groups the overall CPR performance was of very poor quality, and unlikely to have affected outcome in a real situation. Other telephone assisted CPR scripts should be tested in this potential bystander group.

Outcome when adrenaline (epinephrine) was actually given vs. not given - post hoc analysis of a randomized clinical trial.

PURPOSE OF THE STUDY IV line insertion and drugs did not affect long-term survival in an out-of-hospital cardiac arrest (OHCA) randomized clinical trial (RCT). In a previous large registry study adrenaline was negatively associated with survival from OHCA. The present post hoc analysis on the RCT data compares outcomes for patients actually receiving adrenaline to those not receiving adrenaline. MATERIALS AND METHODS Patients from a RCT performed May 2003 to April 2008 were included. Three patients from the original intention-to-treat analysis were excluded due to insufficient documentation of adrenaline administration. Quality of cardiopulmonary resuscitation (CPR) and clinical outcomes were compared. RESULTS Clinical characteristics were similar and CPR quality comparable and within guideline recommendations for 367 patients receiving adrenaline and 481 patients not receiving adrenaline. Odds ratio (OR) for being admitted to hospital, being discharged from hospital and surviving with favourable neurological outcome for the adrenaline vs. no-adrenaline group was 2.5 (CI 1.9, 3.4), 0.5 (CI 0.3, 0.8) and 0.4 (CI 0.2, 0.7), respectively. Ventricular fibrillation, response interval, witnessed arrest, gender, age and endotracheal intubation were confounders in multivariate logistic regression analysis. OR for survival for adrenaline vs. no-adrenaline adjusted for confounders was 0.52 (95% CI: 0.29, 0.92). CONCLUSION Receiving adrenaline was associated with improved short-term survival, but decreased survival to hospital discharge and survival with favourable neurological outcome after OHCA. This post hoc survival analysis is in contrast to the previous intention-to-treat analysis of the same data, but agrees with previous non-randomized registry data. This shows limitations of non-randomized or non-intention-to-treat analyses.

Delaying Defibrillation to Give Basic Cardiopulmonary Resuscitation to Patients With Out-of-Hospital Ventricular Fibrillation

Context Defibrillationassoonaspossibleisstandardtreatmentforpatientswithven-tricular fibrillation. A nonrandomized study indicates that after a few minutes of ven-tricular fibrillation, delaying defibrillation to give cardiopulmonary resuscitation (CPR)first might improve the outcome.Objective To determine the effects of CPR before defibrillation on outcome in pa-tients with ventricular fibrillation and with response times either up to or longer than5 minutes.Design, Setting, and Patients Randomized trial of 200 patients with out-of-hospital ventricular fibrillation in Oslo, Norway, between June 1998 and May 2001.Patientsreceivedeitherstandardcarewithimmediatedefibrillation(n=96)orCPRfirstwith 3 minutes of basic CPR by ambulance personnel prior to defibrillation (n=104).If initial defibrillation was unsuccessful, the standard group received 1 minute of CPRbeforeadditionaldefibrillationattemptscomparedwith3minutesintheCPRfirstgroup.MainOutcomeMeasure Primaryendpointwassurvivaltohospitaldischarge.Sec-ondaryendpointswerehospitaladmissionwithreturnofspontaneouscirculation(ROSC),1-year survival, and neurological outcome. A prespecified analysis examined sub-groups with response times either up to or longer than 5 minutes.Results In the standard group, 14 (15%) of 96 patients survived to hospital dis-charge vs 23 (22%) of 104 in the CPR first group (

A peer-training model for instruction of basic cardiac life support

This study evaluates a peer-training model for cardiopulmonary resuscitation (CPR) instruction for laypersons. Forty-one Norwegian factory employees were trained in CPR and given instructor training. These first trainees then trained 311 co-workers. These employees then trained 873 family members and associates at home. The reference group consists of employees in a Massachusetts commercial hotel trained in seven American Red Cross (ARC): Adult CPR classes. The Norwegian home trainees learned CPR using a cardboard training manikin and were trained by Norwegian factory employees who had learned CPR from co-workers. Trainees were evaluated using skill sheets and a Laerdal Skillmeter manikin. The performance of the Norwegians trained at home by peers did not differ from that of the ARC: Adult CPR trainees in six skills of the initial sequence of CPR. The home trainees outperformed the ARC: Adult CPR trainees in the proportion of compressions delivered correctly (P = 0.032) and ventilations delivered correctly (P = 0.015). Peer training may provide CPR instruction comparable to training in CPR classes at lower cost and with potential to reach new population segments.