Samuel J. Stratton

A Reappraisal of Mouth-to-Mouth Ventilation During Bystander-Initiated Cardiopulmonary Resuscitation A Statement for Healthcare Professionals From the Ventilation Working Group of the Basic Life Support and Pediatric Life Support Subcommittees, American Heart Association

Cardiopulmonary resuscitation (CPR) performed by bystanders clearly improves survival and victims of out-of-hospital cardiac arrest and other life-threatening conditions such as drowning and respiratory arrest.1 2 However, despite three decades of promulgation, CPR is not performed for the majority of victims who require lifesaving care.3 4 5 6 Studies have identified reticence to perform mouth-to-mouth ventilation as a significant barrier to more frequent performance of bystander CPR.1 7 8 9 10 11 12 13 In addition to acting as a barrier to initiation of CPR, the mouth-to-mouth ventilation component of CPR may have other adverse effects, such as promoting gastric insufflation14 15 16 17 or decreasing the percentage of time allocated to effective chest compression.18 19 20 Because early CPR plays a central role in saving lives, the Ventilation Working Group of the Basic Life Support (BLS) and Pediatric Life Support Subcommittees of the AHA Emergency Cardiovascular Care (ECC) Committee reviewed the scientific evidence on mouth-to-mouth ventilation. The ECC Committee and its subcommittees prepare guidelines and recommendations for providing emergency cardiovascular care and cardiopulmonary resuscitation in the United States and will formally review and publish updated guidelines in the year 2000. Although this report represents a focused analysis and serves as a consensus statement regarding the role of mouth-to-mouth ventilation during CPR, it is not intended to change any current AHA recommendations or guidelines for performance of CPR. The specific purpose of this report is to review the historical rationale for providing mouth-to-mouth ventilation during CPR and to critically analyze, using the available scientific literature, the following questions: (1) Does assisted ventilation during CPR result in improved physiological status or survival? (2) Are there adverse effects that result from inclusion of mouth-to-mouth ventilation in basic CPR techniques? (3) Could mouth-to-mouth ventilation be deferred or delayed …

Integration of pre-hospital electrocardiograms and ST-elevation myocardial infarction receiving center (SRC) networks: impact on Door-to-Balloon times across 10 independent regions.

OBJECTIVES The aim of this study was to evaluate the rate of timely reperfusion for ST-elevation myocardial infarction (STEMI) with primary percutaneous coronary intervention (PPCI) in regional STEMI Receiving Center (SRC) networks. BACKGROUND The American College of Cardiology Door-to-Balloon (D2B) Alliance target is a >75% rate of D2B <or=90 min. Independent initiatives nationwide have organized regional SRC networks that coordinate universal access to 9-1-1 with the pre-hospital electrocardiogram (PH-ECG) diagnosis of STEMI and immediate transport to a SRC (designated PPCI-capable hospital). METHODS A pooled analysis of 10 independent, prospective, observational registries involving 72 hospitals was performed. Data were collected on all consecutive patients with a PH-ECG diagnosis of STEMI. The D2B and emergency medical services (EMS)-to-balloon (E2B) times were recorded. RESULTS Paramedics transported 2,712 patients with a PH-ECG diagnosis of STEMI directly to the nearest SRC. A PPCI was performed in 2,053 patients (76%) with an 86% rate of D2B <or=90 min (95% confidence interval: 84.4% to 87.4%). Secondary analyses of this cohort demonstrated a 50% rate of D2B <or=60 min (n = 1,031), 25% rate of D2B <or=45 min (n = 517), and an 8% rate of D2B <or=30 min (n = 155). A tertiary analysis restricted to 762 of 2,053 (37%) cases demonstrated a 68% rate of E2B <or=90 min. CONCLUSIONS Ten independent regional SRC networks demonstrated a combined 86% rate of D2B <or=90 min, and each region individually surpassed the American College of Cardiology D2B Alliance benchmark. In areas with regional SRC networks, 9-1-1 provides entire communities with timely access to quality STEMI care.

Prehospital use of magnesium sulfate as neuroprotection in acute stroke.

BACKGROUND Magnesium sulfate is neuroprotective in preclinical models of stroke and has shown signals of potential efficacy with an acceptable safety profile when delivered early after stroke onset in humans. Delayed initiation of neuroprotective agents has hindered earlier phase 3 trials of neuroprotective agents. METHODS We randomly assigned patients with suspected stroke to receive either intravenous magnesium sulfate or placebo, beginning within 2 hours after symptom onset. A loading dose was initiated by paramedics before the patient arrived at the hospital, and a 24-hour maintenance infusion was started on the patients arrival at the hospital. The primary outcome was the degree of disability at 90 days, as measured by scores on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability). RESULTS Among the 1700 enrolled patients (857 in the magnesium group and 843 in the placebo group), the mean (±SD) age was 69±13 years, 42.6% were women, and the mean pretreatment score on the Los Angeles Motor Scale of stroke severity (range, 0 to 10, with higher scores indicating greater motor deficits) was 3.7±1.3. The final diagnosis of the qualifying event was cerebral ischemia in 73.3% of patients, intracranial hemorrhage in 22.8%, and a stroke-mimicking condition in 3.9%. The median interval between the time the patient was last known to be free of stroke symptoms and the start of the study-drug infusion was 45 minutes (interquartile range, 35 to 62), and 74.3% of patients received the study-drug infusion within the first hour after symptom onset. There was no significant shift in the distribution of 90-day disability outcomes on the global modified Rankin scale between patients in the magnesium group and those in the placebo group (P=0.28 by the Cochran-Mantel-Haenszel test); mean scores at 90 days did not differ between the magnesium group and the placebo group (2.7 in each group, P=1.00). No significant between-group differences were noted with respect to mortality (15.4% in the magnesium group and 15.5% in the placebo group, P=0.95) or all serious adverse events. CONCLUSIONS Prehospital initiation of magnesium sulfate therapy was safe and allowed the start of therapy within 2 hours after the onset of stroke symptoms, but it did not improve disability outcomes at 90 days. (Funded by the National Institute of Neurological Disorders and Stroke; FAST-MAG ClinicalTrials.gov number, NCT00059332.).

Sudden Death in Individuals in Hobble Restraints During Paramedic Transport

For patient and personnel safety, agitated and violent individuals are sometime physically restrained during out-of-hospital ambulance transport. We report two cases of unexpected death in restrained, agitated individuals while they were being trans-ported by advanced life support ambulance. Both patients had been placed in hobble restraints by law enforcement. At autopsy, toxicologic analysis revealed nonlethal levels of amphetamines in one patient and nonlethal levels of ethanol, cocaine, and amphetamines in the other. In both cases the cause of death was determined to be positional asphyxiation during restraint for excited delirium. Physicians and emergency service personnel should be aware of the potential complications of using physical restraints for control of agitated patients.

Prospective study of manikin-only versus manikin and human subject endotracheal intubation training of paramedics

STUDY OBJECTIVES To determine the effect of manikin-only training on field success of endotracheal intubation by paramedics. DESIGN Prospective evaluation of individual field endotracheal intubation success rates for paramedics after they participated in a manikin-only or a manikin-plus-cadaver training program. TYPES OF PARTICIPANTS Paramedics responding to emergency calls involving adult medical or trauma victims. INTERVENTIONS All participants were trained using a controlled manikin training program; then, half were randomly selected for additional instruction using fresh human cadavers. MEASUREMENTS AND MAIN RESULTS Individuals trained using only the manikin program had mean +/- SD individual success rates of 82 +/- 32%, and individuals who received additional cadaver training had mean individual success rates of 83 +/- 31%. Overall success rates for the two groups were 86% for the manikin-only group and 85% for the manikin-plus-cadaver-trained group. The sample size was not adequate to allow rejection of the null hypothesis. CONCLUSION Paramedics trained in endotracheal intubation using a systematic manikin-only teaching program can attain acceptable individual success rates in the actual field setting.

Outcome of out-of-hospital postcountershock asystole and pulseless electrical activity versus primary asystole and pulseless electrical activity.

Objective In the prehospital setting, countershock terminates ventricular fibrillation (VF) in about 80% of cases. However, countershock is most commonly followed by asystole or pulseless electrical activity (PEA). The consequences of such a countershock outcome have not been well studied. The purpose of this investigation was to compare the outcome of prehospital VF victims shocked into asystole or PEA with that of patients whose first documented rhythm was asystole or PEA (primary asystole or PEA). Design Observational, retrospective study conducted over 5 yrs (1995–1999). Setting A municipal hospital with a catchment area of >200,000. Patients Consecutive adult patients with out-of-hospital nontraumatic cardiopulmonary arrest of cardiac origin. Patients found in VF who developed asystole or PEA after countershocks (group 1) and patients found in asystole or PEA (primary asystole or PEA) (group 2) were included if the reported downtime was <10 min. Interventions None. Measurements and Results Study end points included restoration of circulation (defined as a pulse for any duration), survival to hospital admission, and survival to hospital discharge. Ratios were determined, 95% confidence intervals were calculated, and observed differences were compared. For group 1 patients (n = 101), 61% of patients had a bystander-witnessed collapse and 34% received bystander cardiopulmonary resuscitation. For group 2 patients (n = 140), collapse was bystander witnessed in 71% and 45% received bystander cardiopulmonary resuscitation. These differences were not statistically significant. Restoration of circulation was significantly more frequent in group 2 than group 1 (42% vs. 16%, p < .001) as was survival to hospital admission (36% vs. 11%, p = .001). Survival to hospital discharge was greater in group 2 patients, but the difference failed to achieve statistical significance (10% vs. 3%, p = .062). Conclusions Countershock of prolonged VF followed by a nonperfusing rhythm has a worse prognosis than primary asystole or PEA and may be related to myocardial electrical injury.

Prehospital pulseless, unconscious penetrating trauma victims: field assessments associated with survival.

BACKGROUND This study was designed to determine whether out-of-hospital clinical signs could be associated with functional survival for pulseless, unconscious victims of penetrating trauma. METHODS A retrospective review of medical data and outcome for pulseless, unconscious penetrating urban trauma victims during 1993-1994. For comparison with the penetrating study group, data for blunt pulseless, unconscious trauma victims for the same period are reported. Logistic regression, odds ratios, positive predictive values, sensitivity, and specificity were used to determine the possible association of field clinical signs with survival. RESULTS A total of 879 penetrating and blunt trauma victims met criteria of the study. Four of 497 victims of penetrating injury survived. Three of the four survivors were neurologically intact, with the remaining survivor impaired but functional in a supervised work setting. All survivors of penetrating trauma had monitored cardiac electrical (sinus rhythm or sinus tachycardia) activity on presentation in the field, and three were stabbing victims. Age, total field treatment time, spontaneous respiration, reactive pupils, and return of pulse in the field were not found to be associated with survival. Four victims of penetrating injury survived long enough to donate perfused asystolic-sensitive (kidney, liver, lung, and pancreas) organs. There were 382 victims of blunt injury that met study inclusion criteria with five survivors. None of the five survivors of blunt injury had good neurologic function. CONCLUSION Functional survival was rare but did occur with penetrating trauma presenting pulseless and unconscious in the out-of-hospital setting. Although the presence of a pulseless sinus rhythm or tachycardia and stabbing as a mechanism seemed to indicate better survival rates, our study failed to identify reliable out-of-hospital criteria to separate salvageable penetrating trauma victims from those who are nonsalvageable. With this lack of reliable criteria, aggressive prehospital resuscitation efforts and rapid transport to the nearest trauma center for pulseless, unconscious victims of penetrating injury seem indicated.

Outcome From Out-of-hospital Cardiac Arrest Caused by Nonventricular Arrhythmias: Contribution of Successful Resuscitation to Overall Survivorship Supports the Current Practice of Initiating Out-of-hospital ACLS

STUDY OBJECTIVE Studies indicate that ventricular tachycardia (VT) and ventricular fibrillation (VF) are no longer the most common rhythms initially documented in out-of-hospital sudden cardiac death. Although the outcome from asystole and rhythms designated as pulseless electrical activity (PEA) is reported as poor (approximately 1% survival), resuscitative efforts for these patients are still encouraged. The purpose of this study was to determine the potential contribution that this patient group makes to overall survivorship. METHODS During this 2-year prospective study, all patients in cardiopulmonary arrest who were transported to the study institution after out-of-hospital Advanced Cardiac Life Support (ACLS) interventions were considered eligible for inclusion. Patients younger than 18 years of age and those in posttraumatic arrest were excluded. Age, sex, first-documented arrest rhythm, presence of a witness to the arrest, performance of bystander CPR, survival to hospital discharge, and functional status at discharge were recorded. RESULTS A total of 197 patients met the inclusion criteria. The initial rhythm was VF/VT in 59 (30%; 95% confidence interval [CI], 24% to 37%) and asystole/PEA in 138 (70%; 95% CI, 64% to 76%). There was 1 hospital survivor in the VT/VF group; 9 patients (7%; 95% CI, 4% to 13%) in the asystole/PEA group survived to hospital discharge. Of the asystole/PEA survivors, 100% (95% CI, 66% to 100%) had a witnessed arrest and 56% (95% CI, 21% to 86%) received bystander CPR. Fifty-six percent (95% CI, 21% to 86%) of the asystole/PEA survivors were discharged at a functional level equivalent to that preceding arrest. CONCLUSION In this study, patients in asystole/PEA comprised 90% of the survivors. The outcome for patients with asystole/PEA whose arrest was witnessed and who received bystander CPR may be greater than previously estimated and supports the current practice of initiating aggressive out-of-hospital ACLS in this patient group.

Endotracheal drug administration during out-of-hospital resuscitation: where are the survivors?

BACKGROUND Drugs administered endotracheally are effectively absorbed during normal spontaneous cardiac activity. However, animal cardiac arrest studies and limited clinical investigations do not support either the use of endotracheal (ET) drugs in doses currently recommended for adults or the method of direct endotracheal instillation. The purpose of this study was to compare the effect of intravenous (IV) and ET drug therapy on outcome from out-of-hospital cardiac arrest secondary to all cardiac arrest rhythms. DESIGN Five and one-half year retrospective cohort study. SETTING Municipal, university affiliated hospital. PATIENTS Consecutive patients >18 years of age in nontraumatic out-of-hospital cardiac arrest who received advanced cardiac life support (ACLS) medications by only the ET or IV route were included. INTERVENTIONS None. RESULTS Five hundred and ninety-six patients met inclusion criteria (IV drugs=495, ET drugs=101). There was no difference between groups in the rate of witnessed arrest and the frequency of bystander cardiopulmonary resuscitation (CPR). In the ET drug group, a significantly greater number of patients had an initial documented arrest rhythm of asystole compared to the IV drug group (56 vs 37%, P=0.01). The rate of return of spontaneous circulation (27 vs 15%, P=0.01) and survival to hospital admission rate (20 vs 9%, P=0.01) were significantly greater in the IV drug group. No patient who received ET drugs survived to hospital discharge compared to 5% of those receiving IV drugs (P=0.01). CONCLUSION For our out-of-hospital advanced rescuer system, ET drugs at recommended doses (twice the IV dose) injected into an ET tube during cardiac arrest and CPR were of no benefit.

The 1994 Northridge earthquake disaster response: the local emergency medical services agency experience.

INTRODUCTION This paper describes the 1994 Northridge earthquake experience of the local emergency medical services (EMS) agency. Discussed are means that should improve future local agency disaster responses. METHODS Data reported are descriptive and were collected from multiple independent sources, and can be reviewed publicly and confirmed. Validated data collected during the disaster by the Local EMS Agency also are reported. RESULTS The experience of the Los Angeles County EMS Agency was similar to that of earthquake disasters previously reported. Communication systems, water, food, shelter, sanitation means, power sources, and medical supplies were resources needed early in the disaster. Urban Search and Rescue Teams and Disaster Medical Assistance Teams were important elements in the response to the Northridge earthquake. The acute phase of the disaster ended within 48 to 72 hours and public health then became the predominant health-care issue. Locating community food and water supplies near shelters, providing transportation to medical care, and public-health visits to shelter locations helped prevent the development of long-term park encampments. An incident command system for the field, hospitals, and government responders was necessary for an organized response to the disaster. CONCLUSION Disaster preparedness, multiple forms of reliable communication, rapid mobilization of resources, and knowledge of available state and federal resources are necessary for a disaster response by a local EMS agency.