[Show abstract][Hide abstract] ABSTRACT: Despite their wide use, whether antiarrhythmic drugs improve survival after out-of-hospital cardiac arrest (OHCA) is not known. The ROC-ALPS is evaluating the effectiveness of these drugs for OHCA due to shock-refractory ventricular fibrillation or pulseless ventricular tachycardia (VF/VT).
ALPS will randomize 3,000 adults across North America with nontraumatic OHCA, persistent or recurring VF/VT after ≥1 shock, and established vascular access to receive up to 450 mg amiodarone, 180 mg lidocaine, or placebo in the field using a double-blind protocol, along with standard resuscitation measures. The designated target population is all eligible randomized recipients of any dose of ALPS drug whose initial OHCA rhythm was VF/VT. A safety analysis includes all randomized patients regardless of their eligibility, initial arrhythmia, or actual receipt of ALPS drug. The primary outcome of ALPS is survival to hospital discharge; a secondary outcome is functional survival at discharge assessed as a modified Rankin Scale score ≤3.
The principal aim of ALPS is to determine if survival is improved by amiodarone compared with placebo; secondary aim is to determine if survival is improved by lidocaine vs placebo and/or by amiodarone vs lidocaine. Prioritizing comparisons in this manner acknowledges where differences in outcome are most expected based on existing knowledge. Each aim also represents a clinically relevant comparison between treatments that is worth investigating.
Results from ALPS will provide important information about the choice and value of antiarrhythmic therapies for VF/VT arrest with direct implications for resuscitation guidelines and clinical practice.
American heart journal 05/2014; 167(5):653-659.e4. · 4.65 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Abstract Background. Improving survival from out-of-hospital cardiac arrest is an ongoing challenge for emergency medical services (EMS). Various strategies for shortening the time from collapse to defibrillation have been used, and one is to equip police officers with defibrillators. Objective. We evaluated the programmatic implementation of police defibrillation to determine if such a program could improve the process of care in a high-functioning and mature EMS system. Methods. We conducted a prospective observational study of implementation of a police defibrillation in two police departments in King County, Washington, from March 1, 2010 to March 31, 2012. The program was designed to dispatch police specifically to cases with a high suspicion of cardiac arrest, defined as a patient who was unconscious and not breathing normally. We included all nontraumatic out-of-hospital cardiac arrest events that occurred prior to EMS arrival and within the city limits of the two cities. We collected both EMS and police dispatch reports to document times of call receipt, dispatch, and arrival of both agencies. We obtained rhythm recordings when the automated external defibrillators (AEDs) were used by the police. Descriptive statistics were used to measure frequency of police dispatch and to compare times to treatment between patients with a police response and those without. Results. During the study period there were 231 cases of cardiac arrest that occurred prior to EMS arrival eligible for police response in the study communities. Police were dispatched to 124 (54%) of these cases. Of the 124, the police arrived before EMS 37 times, or 16% of the 231 cases. Police performed CPR in 29 of these cases and applied the AED in 21 of them. Of the 21 cases in which the AED was applied for cardiac arrest, a shock was delivered on first analysis for 6 patients. Although the response interval between dispatch to scene arrival was similar for EMS and police (4.5 minutes versus 4.6 minutes respectively, p = 0.08), police were dispatched considerably slower than EMS (1.8 minutes versus 0.6 minutes, p < 0.001). Conclusions. In the current programmatic implementation, police had a measurable but limited involvement in resuscitation. Efforts to address dispatch challenges may improve police involvement.
Prehospital Emergency Care 09/2013; · 1.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Antiarrhythmic drugs like lidocaine are usually given to promote return of spontaneous circulation (ROSC) during ongoing out-of-hospital cardiac arrest (OHCA) from ventricular fibrillation/tachycardia (VF/VT). Whether administering such drugs prophylactically for post-resuscitation care after ROSC prevents re-arrest and improves outcome is unstudied. METHODS: We evaluated a cohort of 1721 patients with witnessed VF/VT OHCA who did (1296) or did not receive prophylactic lidocaine (425) at first ROSC. Study endpoints included re-arrest, hospital admission and survival. RESULTS: Prophylacic lidocaine recipients and non-recipients were comparable, except for shorter time to first ROSC and higher systolic blood pressure at ROSC in those receiving lidocaine. After initial ROSC, arrest from VF/VT recurred in 16.7% and from non-shockable arrhythmias in 3.2% of prophylactic lidocaine recipients, 93.5% of whom were admitted to hospital and 62.4% discharged alive, as compared with 37.4%, 7.8%, 84.9% and 44.5%, of corresponding non-recipients (all p<0.0001). Adjusted for pertinent covariates, prophylactic lidocaine was independently associated with reduced odds of re-arrest from VF/VT, odds ratio, (95% confidence interval) 0.34 (0.26-0.44) and from nonshockable arrhythmias (0.47 (0.29-0.78)); a higher hospital admission rate (1.88, (1.28-2.76)) and improved survival to discharge (1.49 (1.15-1.95)). However in a propensity score-matched sensitivity analysis, lidocaine's only beneficial association with outcome was in a lower incidence of recurrent VF/VT arrest. CONCLUSIONS: Administration of prophylactic lidocaine upon ROSC after OHCA was consistently associated with less recurrent VF/VT arrest, and therapeutic equipoise for other measures. The prospect of a promising association between lidocaine prophylaxis and outcome, without evidence of harm, warrants further investigation.
[Show abstract][Hide abstract] ABSTRACT: Perishock pauses are pauses in chest compressions before and after defibrillatory shock. We examined the relationship between perishock pauses and survival to hospital discharge.
We included out-of-hospital cardiac arrest patients in the Resuscitation Outcomes Consortium Epistry-Cardiac Arrest who suffered arrest between December 2005 and June 2007, presented with a shockable rhythm (ventricular fibrillation or pulseless ventricular tachycardia), and had cardiopulmonary resuscitation process data for at least 1 shock (n=815). We used multivariable logistic regression to determine the association between survival and perishock pauses. In an analysis adjusted for Utstein predictors of survival, the odds of survival were significantly lower for patients with preshock pause ≥20 seconds (odds ratio, 0.47; 95% confidence interval, 0.27 to 0.82) and perishock pause ≥40 seconds (odds ratio, 0.54; 95% confidence interval, 0.31 to 0.97) compared with patients with preshock pause <10 seconds and perishock pause <20 seconds. Postshock pause was not independently associated with a significant change in the odds of survival. Log-linear modeling depicted a decrease in survival to hospital discharge of 18% and 14% for every 5-second increase in both preshock and perishock pause interval (up to 40 and 50 seconds, respectively), with no significant association noted with changes in the postshock pause interval.
In patients with cardiac arrest presenting in a shockable rhythm, longer perishock and preshock pauses were independently associated with a decrease in survival to hospital discharge. The impact of preshock pause on survival suggests that refinement of automatic defibrillator software and paramedic education to minimize preshock pause delays may have a significant impact on survival.
[Show abstract][Hide abstract] ABSTRACT: We examined the effect of the 2005 American Heart Association guidelines on survival in the Resuscitation Outcomes Consortium (ROC) Cardiac Arrest Epistry.
We surveyed 174 EMS agencies from 8 of 10 ROC sites to determine 2005 AHA guideline implementation, or crossover, date. Two sites with 2005 compatible treatment algorithms prior to guideline release, and agencies that did not adopt the new guidelines during the study period were excluded. Non-traumatic adult cardiac arrests that were not witnessed by EMS, and did not have do not resuscitate orders were included. A linear mixed effects model was applied for survival controlling for time and agency. The "crossover" date was added to the model to determine the effect of the 2005 guidelines.
Of 174 agencies, 85 contributed cases to both cohorts during the 18 month period between 2005/12/01 and 2007/05/31. Of 7779 cases, 5054 occurred during the 13 month (median) interval before crossover and 2725 occurred in the five month (median) interval after crossover. The overall survival rate was 6.1%; 5.8% in the old cohort vs. 6.5%, p=0.23. For VF/VT patients, survival was 14.6% vs. 18.0%, p=0.063. Our model estimated no increase in survival over time (monthly OR 1.014, 95% CI 0.988, 1.041, p=0.28).
This study found no significant change in survival rate over time in the early months after implementation. Further longitudinal study is needed to determine the full impact of the guidelines on survival and methods to translate knowledge quickly and effectively in EMS.
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to test whether an automated external defibrillator (AED) training program would positively affect the mental health of family members of high-risk patients.
A total of 305 patients with ischemic heart disease and their family members were randomized to 1 of 4 AED training programs: 2 video-based training programs and 2 face-to-face training programs that emphasized self-efficacy and perceived control. Patients and family members were surveyed at baseline and 3 and 9 months postischemic event on demographic characteristics, measures of quality of life (Short Form-36), self-efficacy, and perceived control. For this study, family members were the focus rather than the patients.
Regression analyses showed that family members in the face-to-face training programs did not score better on any of the mental health status variables than family members who participated in the other training programs except for an increase in self-efficacy beliefs at 3 months after training.
The findings suggest that a specifically designed AED training program emphasizing self-efficacy and perceived control beliefs is not likely to enhance family member mental health.
Heart & lung: the journal of critical care 03/2011; 40(6):502-10. · 1.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Survival after out-of-hospital cardiac arrest (OOHCA) varies between regions, but the contribution of different factors to this variability is unknown. This study examined whether survival to hospital discharge was related to receiving hospital characteristics, including bed number, capability of performing cardiac catheterization and hospital volume of OOHCA cases.
Prospective observational database of non-traumatic OOHCA assessed by emergency medical services was created in 8 US and 2 Canadian sites from December 1, 2005 to July 1, 2007. Subjects received hospital care after OOHCA, defined as either (1) arriving at hospital with pulses, or (2) arriving at hospital without pulses, but discharged or died > or =1 day later.
A total of 4087 OOHCA subjects were treated at 254 hospitals, and 32% survived to hospital discharge. A majority of subjects (68%) were treated at 116 (46%) hospitals capable of cardiac catheterization. Unadjusted survival to discharge was greater in hospitals performing cardiac catheterization (34% vs. 27%, p=0.001), and in hospitals that received > or =40 patients/year compared to those that received <40 (37% vs. 30%, p=0.01). Survival was not associated with hospital bed number, teaching status or trauma center designation. Length of stay (LOS) for surviving subjects was shorter at hospitals performing cardiac catheterization (p<0.01). After adjusting for all variables, there were no independent associations between survival or LOS and hospital characteristics.
Some subsets of hospitals displayed higher survival and shorter LOS for OOHCA subjects but there was no independent association between hospital characteristics and outcome.
[Show abstract][Hide abstract] ABSTRACT: We investigated 9-1-1 telecommunicators' perceptions of communication difficulties with callers who have limited English proficiency (LEP) and the frequency and outcomes of specific communication behaviors.
A survey was administered to 150 telecommunicators from four 9-1-1 call centers of a metropolitan area in the Pacific Northwest to assess their experience working with LEP callers. In addition, 172 9-1-1 recordings (86 of which were labeled by telecommunicators as having a "language barrier") were abstracted for telecommunicators' communication behaviors and care delivery outcomes. All recordings were for patients who were in presumed cardiac arrest (patient unconscious and not breathing). Additionally, computer-assisted dispatch (CAD) reports were abstracted to assess dispatch practices with regard to timing of basic life support (BLS) and advanced life support (ALS) dispatch.
One hundred twenty-three of the telecommunicators (82%) filled out the survey. The majority (70%) reported that they encounter LEP callers almost daily and most (78%) of them reported that communication difficulties affect the medical care these callers receive. Additionally, the telecommunicators reported that calls with LEP callers are often (36%) stressful. The number one strategy for communication with LEP callers reported by telecommunicators was the use of a telephone interpreter line known as the Language Line. However, the Language Line was utilized in only 13% of LEP calls abstracted for this study. The analysis of 9-1-1 recordings suggests that the LEP callers received more repetition, rephrasing, and slowing of speech than the non-LEP callers. Although there was no difference in time from onset of call to dispatching BLS, there was a significant difference in simultaneous dispatching of BLS and ALS between the LEP calls (20%) and non-LEP calls (38%, p < 0.05).
Our study shows that 9-1-1 telecommunicators believe language barriers with LEP callers negatively impact communication and care outcomes. More research needs to be conducted on "best practices" for phone-based emergency communication with LEP callers. Additionally, LEP communities need to better understand the 9-1-1 system and how to effectively communicate during emergencies.
Prehospital Emergency Care 04/2010; 14(2):265-71. · 1.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Early identification and treatment of patients with severe sepsis improves outcome, yet the role of out-of-hospital intravenous (IV) fluid is unknown.
To determine if the delivery of out-of-hospital fluid in patients with severe sepsis is associated with reduced time to achievement of goal-oriented resuscitation in the emergency department (ED).
We performed a secondary data analysis of a retrospective cohort study in a metropolitan, tertiary care, university-based medical center supported by a two-tiered system of out-of-hospital emergency medical services (EMS) providers. We studied the association between delivery of out-of-hospital fluid by advanced life support (ALS) providers and the achievement of resuscitation endpoints (central venous pressure [CVP] > or =8 mmHg, mean arterial pressure [MAP] > or =65 mmHg, and central venous oxygen saturation [ScvO(2)] > or =70%) within six hours after triage during early goal-directed therapy (EGDT) in the ED.
Twenty five (48%) of 52 patients transported by ALS with severe sepsis received out-of-hospital fluid. Data for age, gender, source of sepsis, and presence of comorbidities were similar between patients who did and did not receive out-of-hospital fluid. Patients receiving out-of-hospital fluid had lower out-of-hospital mean (+/- standard deviation) systolic blood pressure (95 +/- 40 mmHg vs. 117 +/- 29 mmHg; p = 0.03) and higher median (interquartile range) Sequential Organ Failure Assessment (SOFA) scores in the ED (7 [5-8] vs. 4 [4-6]; p = 0.01) than patients not receiving out-of-hospital fluid. Despite greater severity of illness, patients receiving out-of-hospital fluid approached but did not attain a statistically significant increase in the likelihood of achieving MAP > or =65 mmHg within six hours after ED triage (70% vs. 44%, p = 0.09). On average, patients receiving out-of-hospital fluid received twice the fluid volume within one hour after ED triage (1.1 L [1.0-2.0 L] vs. 0.6 L [0.3-1.0 L]; p = 0.01). No difference in achievement of goal CVP (72% vs. 60%; p = 0.6) or goal ScvO(2) (54% vs. 36%; p = 0.25) was observed between groups.
Less than half of patients with severe sepsis transported by ALS received out-of-hospital fluid. Patients receiving out-of-hospital IV access and fluids approached but did not attain a statistically significant increase in the likelihood of achieving goal MAP during EGDT. These preliminary findings require additional investigation to evaluate the optimal role of out-of-hospital resuscitation in treating patients with severe sepsis.
Prehospital Emergency Care 04/2010; 14(2):145-52. · 1.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Early recognition and treatment in severe sepsis improve outcomes. However, out-of-hospital patient characteristics and emergency medical services (EMS) care in severe sepsis is understudied. Our goals were to describe out-of-hospital characteristics and EMS care in patients with severe sepsis and to evaluate associations between out-of-hospital characteristics and severity of organ dysfunction in the emergency department (ED).
We performed a secondary data analysis of existing data from patients with severe sepsis transported by EMS to an academic medical center. We constructed multivariable linear regression models to determine if out-of-hospital factors are associated with serum lactate and sequential organ failure assessment (SOFA) in the ED.
Two hundred sixteen patients with severe sepsis arrived by EMS. Median serum lactate in the ED was 3.0 mmol/L (interquartile range, 2.0-5.0) and median SOFA score was 4 (interquartile range, 2-6). Sixty-three percent (135) of patients were transported by advanced life support providers and 30% (62) received intravenous fluid. Lower out-of-hospital Glasgow Coma Scale score was independently associated with elevated serum lactate (P < .01). Out-of-hospital hypotension, greater respiratory rate, and lower Glasgow Coma Scale score were associated with greater SOFA (P < .01).
Out-of-hospital fluid resuscitation occurred in less than one third of patients with severe sepsis, and routinely measured out-of-hospital variables were associated with greater serum lactate and SOFA in the ED.
Journal of critical care 04/2010; 25(4):553-62. · 2.13 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The goal of this investigation was to describe the reasons emergency medical services (EMS) is activated when resuscitation is not desired or when patients show signs of irreversible death.
All medical incident report forms (MIRFs) indicating a cardiac arrest for which resuscitation was withheld were obtained from five participating fire departments. For each eligible case (N = 196), one of the emergency medical technicians (EMTs) present at the scene was interviewed and the dispatch tape of the 9-1-1 call was reviewed. Patient and caller characteristics were abstracted from the MIRFs and dispatch tapes. The EMTs were asked about the reasons for the call, whether the family expected this death, and the caller's emotional state when EMS arrived at the scene. In addition, EMS providers were asked open-ended questions about the services they provided for the patient and patient's family. Using chi-square statistics and t-tests, we compared two groups: 1) patients for whom resuscitation was not desired as indicated by a do-not-resuscitate (DNR) order, terminal illness, or hospice (n = 66) and 2) patients for whom resuscitation was not started because of signs of irreversible death (n = 130).
Compared with callers for patients with signs of irreversible death, callers for patients for whom resuscitation was not desired were less likely to access EMS because they needed medical assistance (11% versus 30%) and more likely to call 9-1-1 because they thought it was "required by law" (30% versus 8%). Other common reasons in both groups for activating 9-1-1 were confusion regarding what to do and a request to confirm death. The most frequently reported service provided by EMTs for both groups was to "offer to contact a chaplain."
In a third of patients for whom EMS did not initiate resuscitation, resuscitation was withheld primarily because it was not desired rather than because there was evidence of irreversible death. Efforts to improve education may prevent EMS activation in these cases. An alternative EMS response could also help ensure patient autonomy and decrease costs to the EMS system.
Prehospital Emergency Care 01/2009; 13(3):335-40. · 1.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The health and policy implications of regional variation in incidence and outcome of out-of-hospital cardiac arrest remain to be determined.
To evaluate whether cardiac arrest incidence and outcome differ across geographic regions.
Prospective observational study (the Resuscitation Outcomes Consortium) of all out-of-hospital cardiac arrests in 10 North American sites (8 US and 2 Canadian) from May 1, 2006, to April 30, 2007, followed up to hospital discharge, and including data available as of June 28, 2008. Cases (aged 0-108 years) were assessed by organized emergency medical services (EMS) personnel, did not have traumatic injury, and received attempts at external defibrillation or chest compressions or resuscitation was not attempted. Census data were used to determine rates adjusted for age and sex.
Incidence rate, mortality rate, case-fatality rate, and survival to discharge for patients assessed or treated by EMS personnel or with an initial rhythm of ventricular fibrillation.
Among the 10 sites, the total catchment population was 21.4 million, and there were 20,520 cardiac arrests. A total of 11,898 (58.0%) had resuscitation attempted; 2729 (22.9% of treated) had initial rhythm of ventricular fibrillation or ventricular tachycardia or rhythms that were shockable by an automated external defibrillator; and 954 (4.6% of total) were discharged alive. The median incidence of EMS-treated cardiac arrest across sites was 52.1 (interquartile range [IQR], 48.0-70.1) per 100,000 population; survival ranged from 3.0% to 16.3%, with a median of 8.4% (IQR, 5.4%-10.4%). Median ventricular fibrillation incidence was 12.6 (IQR, 10.6-5.2) per 100,000 population; survival ranged from 7.7% to 39.9%, with a median of 22.0% (IQR, 15.0%-24.4%), with significant differences across sites for incidence and survival (P<.001).
In this study involving 10 geographic regions in North America, there were significant and important regional differences in out-of-hospital cardiac arrest incidence and outcome.
JAMA The Journal of the American Medical Association 09/2008; 300(12):1423-31. · 29.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We determined the effect of four major program changes over a 30-year period on survival from witnessed cardiac arrest (CA) with ventricular fibrillation (VF) as the rhythm causing collapse.
We conducted an investigation of emergency medical services (EMS)-treated CA occurring between 1978 and 2007. Data were obtained from a registry maintained by the King County Emergency Medical Services Division. Using Utstein style definitions, we measured changes in patient survival in light of four programs that were implemented during the span of the study: defibrillation by emergency medical technicians (EMTs), dispatcher-assisted cardiopulmonary resuscitation (CPR), public access defibrillation, and a CPR-defibrillation protocol that replaced delivery of three sequential shocks with administration of one shock followed by 2 min of CPR.
Overall survival from witnessed VF during the study period was 34%. While demographic characteristics of patients in CA remained constant, we observed greater rates of survival in the years following the program changes, 1983-2006, compared to survival in the period before the changes, 1977-1982. The greatest increase in survival occurred following the CPR-defibrillation protocol change in 2005.
Despite adverse temporal trends, the four program changes appear to have contributed to increasing survival rates from out-of-hospital cardiac arrests in King County.
[Show abstract][Hide abstract] ABSTRACT: The purpose of the present study is to improve understanding of the epidemiology of cardiac arrest in the school setting, with a special focus on the role of school-based automated external defibrillators.
The investigation was a retrospective study of emergency medical service-treated, nontraumatic, out-of-hospital cardiac arrests in Seattle and King County, Washington, that occurred in schools between 1990 and 2005. Cases were identified with cardiac arrest location data from emergency medical service cardiac arrest registries. Patient characteristics, cardiac arrest characteristics, and outcome information were abstracted from the registries and incident report forms. During the study period, 97 cardiac arrests occurred in schools, accounting for 0.4% of all treated cardiac arrests and 2.6% of public location cardiac arrests. Of the 97 cases, 12 cardiac arrests were among students, 33 among faculty and staff, and 45 among adults not employed by the school (7 adults with indeterminate school association). School-based cardiac arrest occurred on average in 1 of 111 schools annually, with a greater annual incidence among colleges (1 cardiac arrest per 8 colleges) than high schools (1 per 125 high schools) or lower-level schools (1 cardiac arrest per 200 preschools through middle schools). The estimated annual incidence of cardiac arrest was 0.18 per 100,000 person-years among students and 4.51 per 100,000 person-years for school faculty and staff.
The present study characterizes school-setting cardiac arrest and provides a framework within which to consider preparation efforts and outcome expectations.
[Show abstract][Hide abstract] ABSTRACT: The majority of cardiac arrests occur in the home. The placement of AEDs in the homes of at-risk patients may save lives through early defibrillation. However, the impact of having an AED in the home on psychological outcomes and quality-of-life is unknown.
The purpose of this research was to determine whether training in the use of and possessing an automated external defibrillator (AED) has an effect on a patient at risk's quality of life.
We investigated the psychological consequences of AED training and possession of such a device for patients who recently experienced an acute ischemic event. One hundred fifty eight patients and their family members were assigned at random to receive cardiopulmonary resuscitation (CPR) training (N=66) or AED/CPR training and possession of the device after training (N=92). We measured quality of life using the Short-Form (SF-36) survey and a 9-item survey we developed specifically for this study to measure differences in social activities and worries about being left alone. Participants answered these questions at enrollment, 2 weeks, 3 months, and 3 months after enrollment.
Patients in the AED group reported lower (worse) scores on most SF-36 subscales at all periods, particularly in those subscales relating to social functioning. The differences were most often small and probably not clinically meaningful. The social activities/worry scales also favored the CPR group at all periods, but with no significant differences.
Physicians counselling patients about AEDs should be aware of the potential effects the device may have on a patient's social functioning.
[Show abstract][Hide abstract] ABSTRACT: Research in an emergency setting is challenging because there may not be sufficient opportunity or time to obtain informed consent from the patient or their legally authorized representative. Such research can be conducted without prior consent if specific criteria are met. However consent is sometimes required for continued participation and may bias the results of the study.
To review regulations related to waiver of consent in emergency research, and evidence of whether such regulations introduce bias.
Emergency research can be conducted without consent, either through community disclosure and consultation followed by patient or family notification and consent for continued participation after the intervention was applied, or under a minimal risk waiver. Review of the clinical record is necessary to determine important outcomes such as survival to discharge. If consent is required for this review but not granted, then these data are missing during analysis. If seriously ill or disadvantaged patients are less likely to assent, then investigators cannot determine reliably whether these vulnerable patients were harmed by the intervention. If missing data are different from complete data, then the analysis is susceptible to bias, and the conclusions could be misleading. Extrapolation from non-consent rates in resuscitation studies to results from the DAVID trial demonstrates that the rate of absence of data and information due to lack of assent can influence whether there is a significant difference between treatment groups (survival of control versus intervention: p=0.04 for complete data; p=0.08 for 10.8% lack of assent; p=0.40 for 19.7% lack of assent).
Exception from consent for emergency research should extend to review of the hospital record as the standard in emergency research. The only potential risk to patients associated with review of the clinical record after the intervention is loss of privacy and confidentiality. Appropriate safeguards can be taken to minimize this risk.