Outcome of cardiac arrests attended by emergency medical services staff at community outpatient dialysis centers.

Cardiac arrest is the leading cause of death among dialysis patients in the United States. We measured the outcome of cardiac arrests attended by Emergency Medical Services (EMS) staff at hemodialysis facilities in a 14-year population-based retrospective study to identify cardiac arrest cases at a dialysis unit. Associated factors were determined using unconditional logistic regression. Of the 102 cardiac arrests identified around the time of dialysis, 10 occurred before, 72 during, and 20 after hemodialysis. The initial measured abnormality was ventricular fibrillation or tachycardia in 72 cases. Of those who survived transportation to a hospital, survival to discharge was 24 with 15% survival at 1 year. Compared to arrests that occurred prior to dialysis, the odds of ventricular fibrillation were 5-fold greater in patients on dialysis but 14-fold greater in those arresting after dialysis. One-third of cases occurred after the introduction of automated external defibrillators, and in half of the cases these devices were attached prior to EMS arrival. Once these devices were attached, most were used for defibrillation. We conclude that ventricular arrhythmias are the predominant features among arrested in-center dialysis patients with most occurrences during dialysis. The role of these devices in dialysis units will need a larger study to evaluate their efficacy.

Factors influencing survival after out-of-hospital cardiac arrest.

Survival to hospital discharge was related to the clinical history and emergency care system factors in 285 patients with witnessed cardiac arrest due to ventricular fibrillation. Only the emergency care factors were associated with differences in outcome. Both the period from collapse until initiation of basic life support and the duration of basic life support before delivery of the first defibrillatory shock were shorter in patients who survived compared with those who died (3.6 +/- 2.5 versus 6.1 +/- 3.3 minutes and 4.3 +/- 3.3 versus 7.3 +/- 4.2 minutes; p less than 0.05). A linear regression model based on emergency response times for 942 patients discovered in ventricular fibrillation was used to estimate expected survival rates if the first-responding rescuers, in addition to paramedics, had been equipped and trained to defibrillate. Expected survival rates were higher with early defibrillation (38 +/- 3%; 95% confidence limits) than the observed rate (28 +/- 3%). Because outcome from cardiac arrest is primarily influenced by delays in providing cardiopulmonary resuscitation and defibrillation, factors affecting response time should be carefully examined by all emergency care systems.

Automatic external defibrillators: importance of field testing to evaluate performance.

A new automatic external defibrillator was tested first against a tape-recorded data base of rhythms and then during use by first-responding fire fighters in a tiered emergency system. The sensitivity for correctly classifying ventricular fibrillation and ventricular tachycardia was substantially less during clinical testing in 298 patients than would have been predicted from preclinical results: 52% of ventricular fibrillation analyses in patients were correctly classified versus 88% of episodes in the data base, and 22 versus 86%, respectively, for ventricular tachycardia (p less than 0.001). The detection algorithm was modified and evaluated further in another 322 patients. The modified detector performed substantially better than did the one that had been designed from prerecorded rhythms: with its use, 118 (94%) of 125 patients in ventricular fibrillation were counter-shocked compared with 91 (77%) of 118 similar patients with use of the initial algorithm (p less than 0.001). No inappropriate shocks were delivered. This improvement resulted in a shorter time to first shock (p less than 0.01) and more shocks being delivered for persistent or recurrent episodes of ventricular fibrillation (p less than 0.05). Of 620 patients treated with the automatic defibrillator, 243 (39%) had ventricular fibrillation; 57 (23%) of the 243 regained pulse and blood pressure before paramedics arrived, 141 (58%) were admitted to hospital and 71 (29%) were discharged.(ABSTRACT TRUNCATED AT 250 WORDS)

Myocardial Infarction Triage and Intervention Project--phase I: patient characteristics and feasibility of prehospital initiation of thrombolytic therapy.

Prehospital initiation of thrombolytic therapy by paramedics, if both feasible and safe, could considerably reduce the time to treatment and possibly decrease the extent of myocardial necrosis in patients with acute coronary thrombosis. Preliminary to a trial of such a treatment strategy, paramedics evaluated the characteristics of 2,472 patients with chest pain of presumed cardiac origin; 677 (27%) had suitable clinical findings consistent with possible acute myocardial infarction and no apparent risk of complication for potential thrombolytic drug treatment. Electrocardiograms (ECGs) of 522 of the 677 patients were transmitted by cellular telephone to a base station physician; 107 (21%) of the tracings showed evidence of ST segment elevation. Of the total 2,472 patients, 453 developed evidence of acute myocardial infarction in the hospital; 163 (36%) of the 453 had met the strict prehospital screening history and examination criteria and 105 (23.9%) showed ST elevation on the ECG and, thus, would have been suitable candidates for prehospital thrombolytic treatment if it had been available. The average time from the onset of chest pain to prehospital diagnosis was 72 +/- 52 min (median 52); this was 73 +/- 44 min (median 62) earlier than the time when thrombolytic treatment was later started in the hospital. Paramedic selection of appropriate patients for potential prehospital initiation of thrombolytic treatment is feasible with use of a directed checklist and cellular-transmitted ECG and saves time. This strategy may reduce the extent and complications of infarction compared with results that can be achieved in a hospital setting.

Occupational exposure to hepatitis B in paramedics.

To determine their occupational risk for hepatitis B infection, 59 Seattle paramedics were tested for hepatitis B serum markers. Evidence of antibody to hepatitis B surface antigen (anti-HBs) or antibody to hepatitis B core antigen (anti-HBc) was found in 25%, a rate five times that of a similar Seattle population. Seropositivity did not correlate with age, race, clinical history, or length of service. Of the 15 paramedics with seropositivity to hepatitis B virus six initially had low titers of either anti-HBs or anti-HBc. Four of the six demonstrated persistent low-grade seropositivity on retesting. Paramedics are at increased risk of hepatitis B infection. The high frequency of low-titer anti-HBs suggests that frequent low-level exposure to hepatitis B virus occurs in this population; hepatitis B vaccine should be strongly considered for paramedics.

Dietary intake of long-chain n-3 polyunsaturated fatty acids and the risk of primary cardiac arrest.

Whether the dietary intake of long-chain n-3 polyunsaturated fatty acids (PUFAs) from seafood reduces the risk of ischemic heart disease remains a source of controversy, in part because studies have yielded inconsistent findings. Results from experimental studies in animals suggest that recent dietary intake of long-chain n-3 PUFAs, compared with saturated and monounsaturated fats, reduces vulnerability to ventricular fibrillation, a life-threatening cardiac arrhythmia that is a major cause of ischemic heart disease mortality. Until recently, whether a similar effect of long-chain n-3 PUFAs from seafood occurred in humans was unknown. We summarize the findings from a population-based case-control study that showed that the dietary intake of long-chain n-3 PUFAs from seafood, measured both directly with a questionnaire and indirectly with a biomarker, is associated with a reduced risk of primary cardiac arrest in humans. The findings also suggest that 1) compared with no seafood intake, modest dietary intake of long-chain n-3 PUFAs from seafood (equivalent to 1 fatty fish meal/wk) is associated with a reduction in the risk of primary cardiac arrest; 2) compared with modest intake, higher intakes of these fatty acids are not associated with a further reduction in such risk; and 3) the reduced risk of primary cardiac arrest may be mediated, at least in part, by the effect of dietary n-3 PUFA intake on cell membrane fatty acid composition. These findings also may help to explain the apparent inconsistencies in earlier studies of long-chain n-3 PUFA intake and ischemic heart disease.

Acute and chronic progressive encephalopathy due to gasoline sniffing.

Acute encephalopathy caused by gasoline sniffing is well recognized, but has been thought to be completely reversible. We report a patient who developed a progressive encephalopathy characterized by ataxia, tremor and dementia following repeated, deliberate gasoline inhalation. Blood and urine lead levels were consistently elevated and at autopsy, the formalin-fixed brain lead content was between 5200 and 6500 micrograms/100 gm of tissue. This case shows that repeated gasoline sniffing can result in irreversible encephalopathy and that both the acute and chronic encephalopathy probably result from organic lead intoxication and not from the gasoline itself.

Progressive multifocal leukoencephalopathy presenting as human immunodeficiency virus type 1 (HIV)-associated dementia.

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disorder of the CNS that usually causes hemiparesis or hemianopsia. Dementia occurs in combination with other neurologic abnormalities. We report a human immunodeficiency virus type 1 (HIV)-infected man whose only manifestation of proven PML was dementia that was clinically indistinguishable from HIV-associated dementia.

Intravenous glucose after out-of-hospital cardiopulmonary arrest: a community-based randomized trial.

QUESTION: Does the common practice of infusing small amounts of glucose after cardiopulmonary arrest worsen neurologic outcome? DESIGN AND SETTING: A community-based randomized trial in Seattle, WA. Paramedics treated all patients with out-of-hospital cardiac arrest in a standard fashion except that the intravenous infusion did or did not contain glucose; ie, patients received either usual treatment, with 5% dextrose in water (D5W), or alternative, with half normal saline (0.45S). OUTCOMES: The main outcome was awakening, defined as the patient having comprehensible speech or following commands as determined by chart review. Other outcomes were survival to hospital admission and to discharge. RESULTS: Over 2 years, paramedics randomized 748 patients. The type of fluid administered was not significantly related to awakening (16.7% for D5W versus 14.6% for 0.45S), admission (38.0% for D5W versus 39.8% for 0.45S), or discharge (15.1% for D5W versus 13.3% for 0.45S). As in previous studies, patients whose arrest had likely been on a cardiac basis with initial rhythms of ventricular fibrillation or asystole had admission blood glucose levels significantly related to awakening: mean = 309 mg/dl for never awakening and 251 mg/dl for awakening. Of note, the relation between glucose and awakening was reversed in the remaining patients, who had electromechanical dissociation or noncardiac mechanisms of arrest. CONCLUSION: Current practices of using limited amounts of glucose-containing solutions after cardiopulmonary arrest do not need to be changed. Blood glucose level on admission is a prognostic indicator but depends on the type of arrest.

Randomized clinical trial of magnesium, diazepam, or both after out-of-hospital cardiac arrest.

OBJECTIVE: To evaluate the feasibility, safety, and efficacy of interventions aimed at improving neurologic outcome after cardiac arrest. METHODS: The authors conducted a double-blind, placebo-controlled, randomized clinical trial with factorial design to see if magnesium, diazepam, or both, when given immediately following resuscitation from out-of-hospital cardiac arrest, would increase the proportion of patients awakening, defined as following commands or having comprehensible speech. If the patient regained a systolic blood pressure of at least 90 mm Hg and had not awakened, paramedics injected IV two syringes stored in a sealed kit. The first always contained either 2 g magnesium sulfate (M) or placebo (P); the second contained either 10 mg diazepam (D) or P. Awakening at any time by 3 months was determined by record review, and independence at 3 months was determined by telephone calls. Over 30 months, 300 patients were randomized in balanced blocks of 4, 75 each to MD, MP, PD, or PP. The study was conducted under waiver of consent. RESULTS: Despite the design, the four treatment groups differed on baseline variables collected before randomization. Percent awake by 3 months for each group were: MD, 29.3%; MP, 46.7%; PD, 30.7%; PP, 37.3%. Percent independent at 3 months were: MD, 17.3%; MP, 34.7%; PD, 17.3%; PP, 25.3%. Significant interactions were lacking. After adjusting for baseline imbalances, none of these differences was significant, and no adverse effects were identified. CONCLUSIONS: Neither magnesium nor diazepam significantly improved neurologic outcome from cardiac arrest.

Cerebrospinal fluid creatine kinase BB isoenzyme activity and neurologic prognosis after cardiac arrest.

OBJECTIVE: To assess the relationship between CSF creatine kinase BB isoenzyme activity (CSF CKBB) and neurologic outcome after cardiac arrest in clinical practice. BACKGROUND: CSF CKBB reflects the extent of brain damage following cardiac arrest. METHODS: To help with prognosis, treating physicians ordered CSF CKBB tests on 474 patients over 7.5 years; 351 of these patients had experienced a cardiac arrest. Assays were performed in one laboratory using agarose electrophoresis. By chart review, we determined awakening status for all patients, defined as the patient having comprehensible speech or following commands. RESULTS: CSF CKBB was usually sampled 48 to 72 hours after cardiac arrest and was strongly associated with awakening (p < < 0.001). The median was 4 U/l for 61 patients who awakened and 191 U/l for 290 who never awakened. For those who awakened, 75% of CKBB levels were < 24 U/l, and for those who never awakened, 75% were > 86 U/l. The highest value in a patient who awakened was 204 U/l, a cutoff that yielded a specificity of 100% of never awakening but a sensitivity of forty-eight percent. Only nine patients who awakened had CSF CKBB values greater than 50 U/l, and none regained independence in activities of daily living. Only three unconscious patients were still alive at last contact, with follow-up of 63, 107, and 109 months. Using logistic regression, the probability of never awakening given a CSF CKBB result can be estimated as: 1/(1 + L), where L = e raised to (0.1267 - 0.0211 x CSF CKBB [U/l]). CONCLUSION: CSF CKBB measurement helps to estimate degree of brain damage and thus neurologic prognosis after cardiac arrest. However, results of this retrospective study could reflect in part a self-fulfilling prophecy.

Outcome and predictors of outcome in pediatric submersion victims receiving prehospital care in King County, Washington.

Predictors of outcome in pediatric submersion victims treated by Seattle and King County's prehospital emergency services were studied. Victims less than 20 years old were identified from hospital admissions and paramedic and medical examiners' reports. The proportion of fatal or severe outcomes in patients were compared with various risk factors. Of 135 patients, 45 died and 5 had severe neurologic impairment. A subset of 38 victims found in cardiopulmonary arrest had a 32% survival rate, with 67% of survivors unimpaired or only mildly impaired. The two risk factors that occurred most commonly in victims who died or were severely impaired were submersion duration greater than 9 minutes (28 patients) and cardiopulmonary resuscitation duration longer than 25 minutes (20 patients). Both factors were ascertained in the prehospital phase of care. Submersion duration was associated with a steadily increasing risk of severe or fatal outcomes: 10% risk (7/67) for 0 to 5 minutes, 56% risk (5/9) for 6 to 9 minutes, 88% risk (21/25) for 10 to 25 minutes, 100% risk (4/4) for greater than 25 minutes. None of 20 children receiving greater than 25 minutes of cardiopulmonary resuscitation escaped death or severe neurologic impairment. Our rates for saving all victims, particularly victims in cardiopulmonary arrest, are considerably higher than has been reported before the children. Prompt prehospital advanced cardiac life support is the most effective means of medical intervention for the pediatric submersion victim. Prehospital information provided the most valuable predictors of outcome.

Comparison of bretylium tosylate and lidocaine in management of out of hospital ventricular fibrillation: a randomized clinical trial.

Bretylium tosylate was compared with lidocaine hydrochloride as initial drug therapy in 146 victims of out of hospital ventricular fibrillation in a randomized blinded trial. An organized rhythm was achieved in 89 and 93 percent and a stable perfusing rhythm in 58 and 60 percent of the patients who received bretylium and lidocaine, respectively. After initiation of advanced life support, an organized rhythm was first established after an average of 10.4 minutes and 10.6 minutes in the two respective groups, requiring an average of 2.8 defibrillatory shocks in those who received bretylium and 2.4 in the lidocaine-treated patients. Comparable numbers of patients were discharged from the hospital: 34 percent of those given bretylium and 26 percent of the patients whose initial therapy was lidocaine. No instance of chemical defibrillation was observed with either drug. In this study, bretylium afforded neither significant advantage nor disadvantage compared with lidocaine in the initial management of ventricular fibrillation.

Cardiac arrest treated with a new automatic external defibrillator by out-of-hospital first responders.

Two hundred sixty patients in cardiac arrest were treated with an automatic external defibrillator by first-responding firefighters before arrival of paramedics. On average, first responders arrived 5 minutes before paramedics. Of 118 patients with ventricular fibrillation, 91 (77%) were administered shocks, 21 (23%) of whom had return of pulse and blood pressure by the time paramedics arrived. Fifty-six (62%) were admitted to the hospital and 30 (33%) survived. The survival rate for all 118 victims discovered with ventricular fibrillation was 27%. The device correctly classified the initial and all subsequent rhythms in 92 patients with asystole, 46 with electromechanical dissociation, and 22 others with presumed respiratory arrest; it did not deliver any inappropriate shocks to patients or to the rescuers using the device. An automatic external defibrillator can be used by first responders as an adjunct to basic life support, and its use may improve survival by shortening the time to defibrillation.

The medical and social impact of nonaccidental injury.

To determine the medical and economic impact of nonaccidental trauma at a regional trauma and emergency care facility, a prospective patient database was used to follow up all victims of intentional injury admitted during one year. Specific patient data were combined with financial data to determine the medical outcome, expenditure, and hospital reimbursement. We found that 17% of the 2451 trauma patients admitted to our facility were victims of nonaccidental injury. The majority of these patients were severely injured, with an average hospital stay of six days. Hospital charges averaged $13,000 per patient. Three fourths of these individuals required governmental funding for medical care. Six months after completion of the review, only two thirds of all expenditures had been reimbursed. These patients represent a high medical services use group and consume a disproportionately high percentage of medical resources.

Analysis of surgical participation in the Advanced Trauma Life Support course. What are the goals and are we meeting them?

Advanced Trauma Life Support (ATLS) course records spanning 4 years were examined and American College of Surgeons members in Washington State surveyed to gain further information on ATLS course participants, skills utilization, and hospital credentialing. Thirty-seven (9.7%) of 382 course participants were trained general surgeons, 56 (14.7%) were surgical residents, and 12 (3.1%) were surgical specialists. One hundred thirty-six (35.6%) of the participants were primary care physicians and 115 (30.1%) were emergency physicians. Surgical residents, primary care physicians, and emergency physicians tended to be overrepresented in ATLS courses in comparison with their general distribution. Fully trained surgeons and surgical specialists were underrepresented. Course participants represented 3.8% of all physicians involved in patient care in the state. Only 6.4% of all active general surgeons in the state were participants, while 39% of active emergency physicians participated. The successful completion rate was 94% (98% for surgeons and 92% for nonsurgical physicians). Thirty-one percent of all American College of Surgeons survey respondents (31% of urban practitioners and 21% of rural practitioners) reported current ATLS qualification. Advanced Trauma Life Support qualification was reported by 31% of respondents as a requirement for taking trauma/emergency department call. Surgeons with a preference not to treat patients with trauma were less likely to have ATLS qualification. More than half of those who reported ATLS qualification had not performed a tracheal intubation, cricothyroidotomy, pericardiocentesis, or emergency department thoracotomy in the previous year. Participation of surgeons in ATLS courses is low, particularly among rural practitioners. Impetus for participation appears related to requirements for hospital staff credentialing and preferences for treating patients with trauma. Performance of procedures taught in the course is rare. Strategies to increase participation need to be formulated and implemented.

The magnitude of acute and chronic alcohol abuse in trauma patients.

OBJECTIVE: To assess the incidence of acute alcohol intoxication and the proportion of trauma patients with evidence of chronic alcohol abuse. DESIGN: Prospective cohort study. SETTING: Regional level I trauma center. PARTICIPANTS: Patients aged 18 years and older admitted with blunt or penetrating trauma. MAIN OUTCOME MEASURES: Admission blood alcohol concentrations (BACs), the Short Michigan Alcohol Screening Test (SMAST), and biochemical markers for chronic alcohol abuse. RESULTS: Of the 2657 patients enrolled, 47.0% had a positive BAC and 35.8% were intoxicated (BAC > or = 100 mg/dL) on admission to the emergency department. Intoxicated patients were more likely to be 25 to 34 years old, male, and nonwhite; the highest proportion of intoxicated patients was among victims of stab wounds. Three fourths of acutely intoxicated patients had evidence of chronic alcoholism as indicated by a positive SMAST, and 25% to 35% of acutely intoxicated patients had biochemical evidence of chronic alcohol abuse. CONCLUSIONS: The high prevalence of both acute intoxication and chronic alcoholism in trauma patients indicates the need to diagnose and appropriately treat this pervasive problem in trauma victims.

Plasma thyroid hormone profiles immediately following out-of-hospital cardiac arrest.

Previous studies have shown abnormal thyroid hormone profiles during cardiac arrest. We explored this association further by characterizing plasma thyroid hormone profiles in 473 patients with out-of-hospital cardiac arrest and correlating them with clinical outcomes. Paramedics collected blood at the end of attempted resuscitation regardless of success. Bloods were collected and processed in a similar manner from 18 control subjects randomly selected from the community. Total thyroxine and total triiodothyronine were lower and reverse triiodothyronine and thyrotropin were higher in cardiac arrest patients than control subjects (all p < 0.001). Except for reverse triiodothyronine, findings were similar for a subgroup of cardiac arrest patients considered to be previously healthy (n = 30). Being discharged alive was associated with total thyroxine, total triiodothyronine and reverse triiodothyronine concentrations closer to the control range and thyrotropin concentrations farther from it, namely higher. In a multivariate stepwise model, only total triiodothyronine and thyrotropin were significantly associated with outcome. Whether these profoundly abnormal profiles represent a pre-existing state or a sudden change of thyroid hormone concentrations cannot be answered with this retrospective study. These observations suggest that thyroid hormones may play a role in the etiology of cardiac arrest, its prognosis, or both.

Empyema thoracis in patients undergoing emergent closed tube thoracostomy for thoracic trauma.

The vast majority of thoracic trauma victims require only observation or tube thoracostomy for definitive treatment of their thoracic injury. Although tube thoracostomy is generally considered a limited intervention, 2 to 25 percent of patients who undergo this procedure develop infectious complications. To determine the incidence and risk factors for the development of empyema thoracis after tube thoracostomy, a retrospective study was undertaken. We found that the development of empyema thoracis was increased in patients whose pleural space was incompletely drained and whose thoracic catheters were in place for a prolonged period.

The sensitivity of vital signs in identifying major thoracoabdominal hemorrhage.

Prehospital and emergency room recordings of hemodynamic vital signs frequently play a major role in the evaluation and treatment of trauma victims. Guidelines for resuscitation and treatment are affected by absolute cutoffs in hemodynamic parameters. To determine the sensitivity of various strata of systolic blood pressure and heart rate in identifying patients with major thoracoabdominal hemorrhage, a 1-year retrospective review was conducted. A third of all patients presented to the emergency department with a normal blood pressure and over three-quarters attained a normal blood pressure during the emergency department evaluation. Although the sensitivity of vital signs in identifying this group of patients improved as the variance from normal increased, standard cutoffs were relatively insensitive. We conclude that normal postinjury vital signs do not predict the absence of potentially life-threatening hemorrhage and abnormal vital signs at any point after injury require investigation to rule out significant blood loss.