Early Magnesium Treatment After Aneurysmal Subarachnoid Hemorrhage: Individual Patient Data Meta-Analysis.

BACKGROUND AND PURPOSE: Delayed cerebral ischemia (DCI) is an important cause of poor outcome after aneurysmal subarachnoid hemorrhage (SAH). Trials of magnesium treatment starting <4 days after symptom onset found no effect on poor outcome or DCI in SAH. Earlier installment of treatment might be more effective, but individual trials had not enough power for such a subanalysis. We performed an individual patient data meta-analysis to study whether magnesium is effective when given within different time frames within 24 hours after the SAH. METHODS: Patients were divided into categories according to the delay between symptom onset and start of the study medication: <6, 6 to 12, 12 to 24, and >24 hours. We calculated adjusted risk ratios with corresponding 95% confidence intervals for magnesium versus placebo treatment for poor outcome and DCI. RESULTS: We included 5 trials totaling 1981 patients; 83 patients started treatment<6 hours. For poor outcome, the adjusted risk ratios of magnesium treatment for start <6 hours were 1.44 (95% confidence interval, 0.83-2.51); for 6 to 12 hours 1.03 (0.65-1.63), for 12 to 24 hours 0.84 (0.65-1.09), and for >24 hours 1.06 (0.87-1.31), and for DCI, <6 hours 1.76 (0.68-4.58), for 6 to 12 hours 2.09 (0.99-4.39), for 12 to 24 hours 0.80 (0.56-1.16), and for >24 hours 1.08 (0.88-1.32). CONCLUSIONS: This meta-analysis suggests no beneficial effect of magnesium treatment on poor outcome or DCI when started early after SAH onset. Although the number of patients was small and a beneficial effect cannot be definitively excluded, we found no justification for a new trial with early magnesium treatment after SAH.

The Utstein template and the effect of in-hospital decisions: the impact of do-not-attempt resuscitation status on survival to discharge statistics.

BACKGROUND: Variables for reporting outcome of pre-hospital cardiac arrest have been delineated in the Utstein style template. The primary outcome statistic is survival to hospital discharge (SHD). The template allows comparisons of pre-hospital care systems and has been used to determine the benefit of pre-hospital interventions. Post-resuscitation care has not been standardized and in-hospital events that affect SHD are not considered in the template. STUDY PURPOSE: To determine the frequency and timing with which do-not-attempt resuscitation (DNAR) status is conferred following resuscitation from pre-hospital cardiac arrest and to assess the impact of this action on SHD. METHODS: A 4-year retrospective, observational cohort study of all adult patients successfully resuscitated from nontraumatic pre-hospital cardiac arrest and admitted to a single municipal teaching hospital. Study variables included age, witnessed arrest, bystander cardiopulmonary resuscitation (CPR), initial rhythm documented by paramedics, hospital admission rate, frequency and time at which DNAR status was conferred, and SHD. RESULTS: Four hundred and eighteen adult patients experienced pre-hospital arrest and received standard advanced cardiac life support interventions during the study period. Seventy-nine patients (19%; 95% confidence interval (CI), 15-23%) survived to be admitted to the hospital. Fifty-four of these patients (68%; 96% CI, 57-78%) were subsequently placed in DNAR status. Only one of these patients had a living will or advanced directive prior to cardiopulmonary arrest. In 37 DNAR patients (68%; 95% CI, 54-81%), DNAR status was conferred within 24 h of hospital admission. For patients made DNAR within 24 h of admission, 38% had a witnessed arrest, 22% had ventricular fibrillation as the first documented arrest rhythm, and 29% received bystander CPR. When patients made DNAR are included in the calculation of SHD rate, the SHD rate for the study period was 5.3% (95% CI, 3.3-7.8%). If DNAR patients are excluded, the SHD was 6.1% (95% CI, 3.8-9.0%), representing a 15% increase in SHD rate. CONCLUSION: In-hospital care and medical decision making are not considered in the Utstein template and can have a significant effect on reported survival statistics. When assessing the benefit of pre-hospital interventions, it may be preferable to consider survival to hospital admission as the primary outcome statistic until such time as post-resuscitation care after hospital admission is rigidly standardized.

Factors associated with sudden death of individuals requiring restraint for excited delirium.

The purpose of this article is to identify and rank factors associated with sudden death of individuals requiring restraint for excited delirium. Eighteen cases of such deaths witnessed by emergency medical service (EMS) personnel are reported. The 18 cases reported were restrained with the wrists and ankles bound and attached behind the back. This restraint technique was also used for all 196 surviving excited delirium victims encountered during the study period. Unique to these data is a description of the initial cardiopulmonary arrest rhythm in 72% of the sudden death cases. Associated with all sudden death cases was struggle by the victim with forced restraint and cessation of struggling with labored or agonal breathing immediately before cardiopulmonary arrest. Also associated was stimulant drug use (78%), chronic disease (56%), and obesity (56%). The primary cardiac arrest rhythm of ventricular tachycardia was found in 1 of 13 victims with confirmed initial cardiac rhythms, with none found in ventricular fibrillation. Our findings indicate that unexpected sudden death when excited delirium victims are restrained in the out-of-hospital setting is not infrequent and can be associated with multiple predictable but usually uncontrollable factors.

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 intubation in patients with severe head injury.

BACKGROUND: Prehospital intubation and airway control is routinely performed by paramedics in critically injured patients. Despite the advantages provided by this procedure, numerous potential risks exist when this is performed in the field. We reviewed the outcome of patients with severe head injury, to determine whether prehospital intubation is associated with an improved outcome. METHODS: A retrospective review of registry data of patients admitted to an urban trauma center with severe head injury (field Glasgow Coma Scale score of < or =8 and head Abbreviated Injury Scale score of > or =3) was performed. Patients were stratified by methods of airway control performed by prehospital personnel: not intubated, intubated, or unsuccessful intubation. Mortality was determined for each group. To control for significant variables between these populations, matching and multivariate analysis were performed. RESULTS: Patients requiring prehospital intubation or in whom intubation was attempted had an increased mortality (81% and 77%, respectively) when compared with nonintubated patients (43%). The mortality for patients who had prehospital intubation performed did not demonstrate an improved survival using matching. In fact, intubated patients had a significantly higher relative risk (RR) of mortality when compared with nonintubation (RR = 1.74,p < 0.001) and unsuccessful intubation patients (RR = 1.53, p = 0.008) CONCLUSION: For patients with severe head injury, prehospital intubation did not demonstrate an improvement in survival. Further prospective randomized trials are necessary to confirm these results.

Design and implementation of a controlled trial of pediatric endotracheal intubation in the out-of-hospital setting.

This article describes the design and implementation of the Pediatric Airway Management Project. The project was completed January 1, 1997, and evaluated the effectiveness of endotracheal intubation relative to bag-valve-mask ventilation in improving survival to hospital discharge and neurologic outcome in children, the effect of training on paramedic airway management skills and self-efficacy, the length of time the skills can be retained, and the costs of training and retraining. The main focus of project design was the implementation of a controlled trial comparing methods of airway management for acutely ill and injured pediatric patients in the out-of-hospital setting. To date, this project is the largest prospective, controlled, out-of-hospital study of the care of children ever reported. Barriers to implementation of a study of this size are described.

Endotracheal versus intravenous epinephrine and atropine in out-of-hospital "primary" and postcountershock asystole.

STUDY OBJECTIVE: Pulmonary blood flow during cardiac arrest and cardiopulmonary resuscitation (CPR) is <20% of normal, and transalveolar drug absorption is likely to be minimal. Animal and clinical CPR studies have not addressed the use of endotracheal (ET) epinephrine in doses currently recommended for adults (twice the intravenous dose). The purpose of this study was to compare the effects of ET and intravenous drugs on cardiac rhythm in the prehospital setting. DESIGN: A 3-yr (1995-1997) retrospective review of all cardiac arrests transported to a single, municipal teaching institution was performed. PATIENTS: Patients >18 yrs in atraumatic cardiac arrest whose first documented field rhythm was asystole with time-to-definitive care of < or =10 mins (primary asystole) and patients found in ventricular fibrillation who developed postcountershock asystole (secondary asystole) were included. Patients were grouped according to route of drug administration (i.v., ET, or no drug therapy) as well as rhythm (primary or secondary asystole). A positive response to drug therapy was defined as any subsequent rhythm other than asystole during continued prehospital resuscitation. MEASUREMENTS AND MAIN RESULTS: A total of 136 patients met inclusion criteria. The following groups were defined: group 1, primary asystole/i.v. drugs (n = 39); group 2, postcountershock asystole/i.v. drugs (n = 39); group 3, primary asystole/ET drugs (n = 25); group 4, postcountershock asystole/ET drugs (n = 18); and group 5, primary or secondary asystole/no drug therapy (n = 15). Significant differences were not observed between groups with respect to age, gender, witnessed arrest, frequency of bystander CPR, or time-to-definitive care. The positive rhythm response rate was significantly greater in group 1 (64%) and group 2 (69%) (both p < .01) than in Group 3 (12%) or group 4 (11%). The response rate in the control group was 20% and not significantly different from either ET group. The intravenous groups also had a significantly greater rate of return of spontaneous circulation (17%) when compared with the ET groups (0%) (p = .005). CONCLUSION: We conclude that the currently recommended doses of epinephrine and atropine administered endotracheally are rarely effective in the setting of cardiac arrest and CPR.

Effect of out-of-hospital pediatric endotracheal intubation on survival and neurological outcome: a controlled clinical trial.

CONTEXT: Endotracheal intubation (ETI) is widely used for airway management of children in the out-of-hospital setting, despite a lack of controlled trials demonstrating a positive effect on survival or neurological outcome. OBJECTIVE: To compare the survival and neurological outcomes of pediatric patients treated with bag-valve-mask ventilation (BVM) with those of patients treated with BVM followed by ETI. DESIGN: Controlled clinical trial, in which patients were assigned to interventions by calendar day from March 15, 1994, through January 1, 1997. SETTING: Two large, urban, rapid-transport emergency medical services (EMS) systems. PARTICIPANTS: A total of 830 consecutive patients aged 12 years or younger or estimated to weigh less than 40 kg who required airway management; 820 were available for follow-up. INTERVENTIONS: Patients were assigned to receive either BVM (odd days; n = 410) or BVM followed by ETI (even days; n = 420). MAIN OUTCOME MEASURES: Survival to hospital discharge and neurological status at discharge from an acute care hospital compared by treatment group. RESULTS: There was no significant difference in survival between the BVM group (123/404 [30%]) and the ETI group (110/416 [26%]) (odds ratio [OR], 0.82; 95% confidence interval [CI], 0.61-1.11) or in the rate of achieving a good neurological outcome (BVM, 92/404 [23%] vs ETI, 85/416 [20%]) (OR, 0.87; 95% CI, 0.62-1.22). CONCLUSION: These results indicate that the addition of out-of-hospital ETI to a paramedic scope of practice that already includes BVM did not improve survival or neurological outcome of pediatric patients treated in an urban EMS system.

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.

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.

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.

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.

Prehospital pediatric endotracheal intubation: a survey of the United States.

INTRODUCTION: The standard of practice and teaching for prehospital pediatric endotracheal intubation (PETI) in the United States currently is unknown. The accepted practice of prehospital PETI is of interest because it has contradictory support in the medical literature. HYPOTHESIS: PETI is an accepted method of prehospital airway control in the United States. METHODS: Nationwide mail survey (June 1991 to March 1992) of each state emergency medical service (EMS) agency and all known paramedic training sites. RESULTS: The use of PETI is supported by 100% of state EMS agencies and the American Virgin Islands. Ninety-seven percent (339 of 349) of the responding (349 of 523) paramedic training sites reported that PETI was taught in their programs. The results of the survey did not identify a predominate method for instructing paramedics in PETI. Lectures, mannequins, operating room demonstration, animal models, and cadavers were used in various ways for teaching the skill. CONCLUSION: Endotracheal intubation is an accepted standard in prehospital pediatric care. This standard exists with marginal support in published literature and study of prehospital PETI is needed to define the benefits, risks, and optimal instruction methods for the procedure.

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.