Biomedical subjects

C E Fahrenbruch

Publications and source records attributed to C E Fahrenbruch.

At least 19 recordsLinked to original sources

PubMed2003

Apolipoprotein E genotypes and outcome from out of hospital cardiac arrest.

Genetic factors may influence outcome from cardiac arrest. In Seattle, WA, paramedics collected blood specimens from patients who had suffered cardiac arrest outside of a medical institution (out of hospital cardiac arrest). We examined associations between apolipoprotein E (APOE) genotype and outcome in 134 who died "in the field", 131 who died in the hospital, 198 patients who were discharged from hospital alive, and 64 control subjects. APOE genotype was not significantly related to outcome, including being alive at and being independent by 3 months after the arrest. Specifically, having one or two alleles of APOE epsilon4 or having APOE epsilon3/epsilon3 was not related to outcome, even after controlling for age, sex, race, and initial rhythm. We failed to confirm previous studies and found no significant associations between APOE genotype and outcome from out of hospital cardiac arrest.

Aged↗

PubMed2002

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.

Activities of Daily Living↗

PubMed2001

Out-of-hospital cardiac arrest in men and women.

BACKGROUND: The incidence of sudden cardiac death is roughly 3 times greater in men than in women. However, in patients treated for out-of-hospital cardiac arrest, the relationships between sex and survival after adjustment for age and cardiac rhythm are unclear. METHODS AND RESULTS: In this retrospective cohort study, we examined 7069 men and 2582 women who were treated for out-of-hospital cardiac arrest in Seattle and suburban King County between 1990 and 1998. We compared successful prehospital resuscitation (hospital admission) and survival from event to discharge in men and women. Women had markedly reduced rates of ventricular fibrillation (VF), slightly older age, fewer witnessed arrests, and fewer arrests in public locations than men. Although their unadjusted resuscitation rate was lower (29% versus 32%, P<0.0001), women had a greater likelihood of resuscitation than men after adjustment for VF (odds ratio [OR] 1.13; 95% confidence interval [CI], 1.03 to 1.25) and after adjustment for VF plus additional factors (OR, 1.27; 95% CI, 1.14 to 1.41). The difference in resuscitation rates between men and women decreased as they aged (test for trend, P<0.0001). Unadjusted survival rates were also lower in women than in men (11% versus 15%, P<0.0001). Women had similar survival after adjustment for VF (OR, 0.97; 95% CI, 0.85 to 1.11) and after adjustment for VF plus additional factors (OR, 1.09; 95% CI, 0.93 to 1.27). CONCLUSIONS: The lower unadjusted resuscitation and survival rates observed in women were primarily due to women's lower incidence of VF, a relatively favorable cardiac rhythm. After adjustment for VF and other factors, women had higher resuscitation rates than men, but similar rates of survival from event to discharge.

Adult↗

PubMed1999

Amiodarone for resuscitation after out-of-hospital cardiac arrest due to ventricular fibrillation.

BACKGROUND: Whether antiarrhythmic drugs improve the rate of successful resuscitation after out-of-hospital cardiac arrest has not been determined in randomized clinical trials. METHODS: We conducted a randomized, double-blind, placebo-controlled study of intravenous amiodarone in patients with out-of-hospital cardiac arrest. Patients who had cardiac arrest with ventricular fibrillation (or pulseless ventricular tachycardia) and who had not been resuscitated after receiving three or more precordial shocks were randomly assigned to receive 300 mg of intravenous amiodarone (246 patients) or placebo (258 patients). RESULTS: The treatment groups had similar clinical profiles. There was no significant difference between the amiodarone and placebo groups in the duration of the resuscitation attempt (42+/-16.4 and 43+/-16.3 minutes, respectively), the number of shocks delivered (4+/-3 and 6+/-5), or the proportion of patients who required additional antiarrhythmic drugs after the administration of the study drug (66 percent and 73 percent). More patients in the amiodarone group than in the placebo group had hypotension (59 percent vs. 48 percent, P=0.04) or bradycardia (41 percent vs. 25 percent, P=0.004) after receiving the study drug. Recipients of amiodarone were more likely to survive to be admitted to the hospital (44 percent, vs. 34 percent of the placebo group; P=0.03). The benefit of amiodarone was consistent among all subgroups and at all times of drug administration. The adjusted odds ratio for survival to admission to the hospital in the amiodarone group as compared with the placebo group was 1.6 (95 percent confidence interval, 1.1 to 2.4; P=0.02). The trial did not have sufficient statistical power to detect differences in survival to hospital discharge, which differed only slightly between the two groups. CONCLUSIONS: In patients with out-of-hospital cardiac arrest due to refractory ventricular arrhythmias, treatment with amiodarone resulted in a higher rate of survival to hospital admission. Whether this benefit extends to survival to discharge from the hospital merits further investigation.

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PubMed1999

Influence of cardiopulmonary resuscitation prior to defibrillation in patients with out-of-hospital ventricular fibrillation.

CONTEXT: Use of automated external defibrillators (AEDs) by first arriving emergency medical technicians (EMTs) is advocated to improve the outcome for out-of-hospital ventricular fibrillation (VF). However, adding AEDs to the emergency medical system in Seattle, Wash, did not improve survival. Studies in animals have shown improved outcomes when cardiopulmonary resuscitation (CPR) was administered prior to an initial shock for VF of several minutes' duration. OBJECTIVE: To evaluate the effects of providing 90 seconds of CPR to persons with out-of-hospital VF prior to delivery of a shock by first-arriving EMTs. DESIGN: Observational, prospectively defined, population-based study with 42 months of preintervention analysis (July 1, 1990-December 31, 1993) and 36 months of post-intervention analysis (January 1, 1994-December 31, 1996). SETTING: Seattle fire department-based, 2-tiered emergency medical system. PARTICIPANTS: A total of 639 patients treated for out-of-hospital VF before the intervention and 478 after the intervention. INTERVENTION: Modification of the protocol for use of AEDs, emphasizing approximately 90 seconds of CPR prior to delivery of a shock. MAIN OUTCOME MEASURES: Survival and neurologic status at hospital discharge determined by retrospective chart review as a function of early (<4 minutes) and later (> or =4 minutes) response intervals. RESULTS: Survival improved from 24% (155/639) to 30% (142/478) (P=.04). That benefit was predominantly in patients for whom the initial response interval was 4 minutes or longer (survival, 17% [56/321] before vs 27% [60/220] after; P = .01). In a multivariate logistic model, adjusting for differences in patient and resuscitation factors between the periods, the protocol intervention was estimated to improve survival significantly (odds ratio, 1.42; 95% confidence interval, 1.07-1.90; P = .02). Overall, the proportion of victims who survived with favorable neurologic recovery increased from 17% (106/634) to 23% (109/474) (P = .01). Among survivors, the proportion having favorable neurologic function at hospital discharge increased from 71% (106/150) to 79% (109/138) (P<.11). CONCLUSION: The routine provision of approximately 90 seconds of CPR prior to use of AED was associated with increased survival when response intervals were 4 minutes or longer.

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PubMed1999

Weekly and seasonal variation in the incidence of cardiac arrests.

Adolescent↗

PubMed1998

Circadian variations in the occurrence of cardiac arrests: initial and repeat episodes.

BACKGROUND: Patterns of temporal variation of cardiac arrests may be important for understanding mechanisms leading to the onset of acute cardiovascular disorders. Previous studies reported diurnal variation of the onset of cardiac arrests, with high incidence in the morning and in the evening, lack of daily variation during the week, and some seasonal variation. The association between the time of day and recurrent cardiac arrests has not been previously examined. METHODS AND RESULTS: We explored temporal variation in 6603 out-of-hospital cardiac arrests attended by the Seattle Fire Department. The data exhibit diurnal variation, with a low incidence at night and two peaks of approximately the same size (at 8 to 11 AM and 4 to 7 PM). The evening peak is attributed primarily to the patients found in ventricular fibrillation, whereas arrests that show other rhythms exhibit mainly a morning peak. Cardiac arrests associated with survival have more pronounced diurnal variation than episodes in which survival did not occur. This difference persists after adjustment for rhythm. For 597 patients who had at least two separate cardiac arrests, we found no overall association between the times of day of the recurrent arrests. For women, however, the times of day of the first and second arrests were closer to each other than one would expect if the times were entirely unrelated. CONCLUSIONS: Cardiac arrests do not occur randomly during the day, but rather follow certain periodic patterns. These patterns are probably associated with patterns of daily activities. The hypothesis that cardiac arrests are triggered by a person's activity rather than by some underlying characteristics of his or her disease is supported by the lack of association between the times of the first and second arrests in the patients with recurrent arrests.

Adolescent↗

PubMed1993

Out-of-hospital cardiac arrest: racial differences in outcome in Seattle.

OBJECTIVES: Out-of-hospital sudden cardiac arrest is a key area in which to study the dual problem of the poorer health status of minority populations and their poorer access to the health care system. We proposed to examine the relationship between race (Black/White) and survival. METHODS: We determined the incidence and outcome of cardiac arrests in Seattle for which medical assistance was requested. RESULTS: Over a 26-month period, the age-adjusted incidence of out-of-hospital cardiac arrest was twice as great in Blacks than in Whites (3.4 vs 1.6 per 1000 aged 20 and over). The initial resuscitation rate was markedly poorer in the Black victims (17.1% vs 40.7%), and rates of survival to hospital discharge were also lower in Blacks (9.4% vs 17.1%). Both effective initial resuscitation and survival were significantly related to White race following adjustment for other covariates. CONCLUSION: The differences in outcomes were not fully explained by features of the collapse or relevant service factors. Possible explanations include delays in instituting therapy, less bystander-initiated cardiopulmonary resuscitation, poorer levels of health, and differences in the underlying cardiac disorders.

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PubMed1992

Influence of coronary bypass surgery on subsequent outcome of patients resuscitated from out of hospital cardiac arrest.

The effect of coronary bypass surgery on recurrent cardiac arrest was estimated in 265 patients resuscitated from out of hospital cardiac arrest between 1970 and 1988. From this cohort, 85 patients (32%) underwent coronary bypass surgery after recovery from cardiac arrest and 180 patients (68%) were treated medically. A multivariate Cox analysis was used to estimate the effect of coronary bypass surgery on subsequent survival after adjusting for effects of age, prior cardiac history, ejection fraction, year of the event, history of angina, antiarrhythmic drug use and whether the arrest was related to acute myocardial infarction. The use of coronary bypass surgery had a significant effect in reducing the incidence of subsequent cardiac arrest during follow-up study (risk ratio [RR] 0.48, 95% confidence interval [CI] 0.24 to 0.97, p less than 0.04). There was also a trend consistent with a reduction in total cardiac mortality (RR 0.65, 95% CI 0.39 to 1.10, p = 0.10). These findings suggest that coronary bypass surgery may reduce the incidence of sudden death in suitable patients resuscitated from an episode of ventricular fibrillation.

Cohort Studies↗

PubMed1992

Community-based interventions for sudden cardiac death. Impact, limitations, and changes.

Since 1970, Seattle Fire Department paramedics have treated 5,120 victims of out-of-hospital ventricular fibrillation (VF). During the past decade, there was an impressive decline in the annual incidence of VF, probably reflecting a general reduction in age-adjusted mortality attributed to coronary heart disease. Since 1975, annual survival rates to hospital discharge fluctuated between 24% and 33%, averaging 28.9%. In spite of continuing efforts to improve basic and advanced life support, survival rates have not risen concomitantly. Since the early 1970s, average ages of victims have increased from 63.4 to 66.1 years (p less than 0.0001). Additionally, in survivors of VF arrest, habitual cigarette smoking has become much less frequent (48% versus 31%, p less than 0.0001). Longevity of VF survivors has improved in recent years, with 1- and 5-year survival rates increasing from 74% and 44%, respectively, for those resuscitated during 1970-1975 to 83% and 57%, respectively, for those resuscitated during 1982-1987 (p less than 0.0001). It is likely that medical or surgical therapy and improved hygienic measures have contributed to the better outcomes. The vast majority of resuscitated victims have not had symptomatic ventricular arrhythmias before VF. Accordingly, current efforts to control such arrhythmias will not have an important impact on the community incidence of sudden cardiac death. Successful strategies for further containment will likely be those that address the problem of coronary atherogenesis, although medical and surgical therapies may also have a role. Additionally, it is timely to evaluate the widespread use of automated defibrillators by persons other than emergency medical technicians or paramedics.

Community Health Services↗

PubMed1991

An antiarrhythmic drug experience in 941 patients resuscitated from an initial cardiac arrest between 1970 and 1985.

Survival rates and antiarrhythmic drug use were determined in 941 consecutive patients resuscitated from prehospital cardiac arrest due to ventricular fibrillation between March 7, 1970, and March 6, 1985. Of these patients, 18.7% were treated for at least a portion of the period with quinidine, 17.5% with procainamide, and 39.4% received no antiarrhythmic agent. Beta blockers were prescribed for 28.3% of the patients. Unadjusted comparisons of survival estimates showed dramatically lower survival rates for patients who received antiarrhythmic drugs independent of beta-blocker therapy and significantly improved survival for patients receiving beta-blocker therapy independent of antiarrhythmic use. Patients for whom antiarrhythmic therapy was prescribed also had more adverse baseline risk factors, whereas patients taking beta blockers had fewer such risk factors. After adjustment for these baseline risk factors, the use of antiarrhythmics was weakly (p less than 0.09) associated with worsened survival; 2-year survival for procainamide-treated patients was 30% and quinidine-treated patients 55% (p = 0.003). Beta-blocker therapy was associated with improved (p less than 0.001) survival. Thus, although neither procainamide nor quinidine appear to have had a benefit on mortality, the effect of procainamide appears to be significantly worse than that of quinidine. The use of antiarrhythmic drug therapy in patients resuscitated from prehospital ventricular fibrillation should be regarded as not only unproved, but potentially hazardous, and should probably be restricted to testing in randomized clinical trials.

Anti-Arrhythmia Agents↗

PubMed1991

Late outcome of survivors of out-of-hospital cardiac arrest with left ventricular ejection fractions greater than or equal to 50% and without significant coronary arterial narrowing.

In a retrospective survey of 1,195 survivors of out-of-hospital ventricular fibrillation, 43 patients were identified in whom left ventricular ejection fraction was greater than or equal to 0.50 and in whom no coronary artery stenosis of greater than or equal to 50% luminal diameter were present. Thirteen (30%) of these patients had hypokinesia on left ventriculography, and 20 patients (47%) had a persistently abnormal electrocardiogram. Seven patients (16%) had recurrent out-of-hospital cardiac arrest during an average follow-up of 86 +/- 54 months. The presence of either wall motion or electrocardiographic abnormalities defined patients with a several-fold higher risk of recurrent cardiac arrest than those without such abnormalities. The risk for recurrent cardiac arrest within 5 years was 30% in those with abnormal electrocardiograms versus 5% in the others (p less than 0.03). Age was an independent predictor of recurrent cardiac arrest in this group (p less than 0.01); surprisingly, recurrent cardiac arrest was occurring more often among younger patients. Although cardiac arrest is unusual in patients without major structural heart disease, its recurrence in such survivors is common. Patients at relatively high risk for recurrent ventricular fibrillation can be identified by their youth and by abnormalities detected on the surface 12-lead electrocardiogram or by contrast left ventriculography.

Adult↗

PubMed1990

Effect of epinephrine and lidocaine therapy on outcome after cardiac arrest due to ventricular fibrillation.

One hundred ninety-nine patients with out-of-hospital cardiac arrest persisted in ventricular fibrillation after the first defibrillation attempt and were then randomly assigned to receive either epinephrine or lidocaine before the next two shocks. The resulting electrocardiographic rhythms and outcomes for each group of patients were compared for each group and also compared with results during the prior 2 years, a period when similar patients primarily received sodium bicarbonate as initial adjunctive therapy. Asystole occurred after defibrillation with threefold frequency after repeated injection of lidocaine (15 of 59, 25%) compared with patients treated with epinephrine (four of 55, 7%) (p less than 0.02). There was no difference in the proportion of patients resuscitated after treatment with either lidocaine or epinephrine (51 of 106, 48% vs. 50 of 93, 54%) and in the proportion surviving (18, 19% vs. 21, 20%), respectively. Resuscitation (64% vs. 50%, p less than 0.005) but not survival rates (24% vs. 20%) were higher during the prior 2-year period in which initial adjunctive drug treatment for persistent ventricular fibrillation primarily consisted of a continuous infusion of sodium bicarbonate. The negative effect of lidocaine or epinephrine treatment was explained in part by their influence on delaying subsequent defibrillation attempts. Survival rates were highest (30%) in a subset of patients who received no drug therapy between shocks. We conclude that currently recommended doses of epinephrine and lidocaine are not useful for improving outcome in patients who persist in ventricular fibrillation.(ABSTRACT TRUNCATED AT 250 WORDS)

Bicarbonates↗

PubMed1989

Prenatal psychological stress, dermatoglyphic asymmetry and pregnancy outcome in the pigtailed macaque (Macaca nemestrina).

The relationships between maternal psychosocial stress during pregnancy and asymmetry in dermal ridge count, gestation length, birth weight percentile and survival were examined in 68 pigtailed macaque offspring. Twenty-five pregnant females were stressed daily by capture from 30 through 130 days postconception; 43 control unstressed females were housed under conditions of minimal disturbance. The difference between total intercore dermal ridge counts between right and left hands of the offspring was used as a measure of the perturbed development that theoretically occurs in the presence of a prenatal stressor. Dermatoglyphic asymmetry was significantly higher in the stressed offspring than in the unstressed group (mean asymmetry = 7.3 +/- 2.8 and 5.4 +/- 2.5, respectively; t = 2.85, p less than 0.01). Although maternal stress alone was not related to differential gestation length, birth weight, or survival, high asymmetry (8-13 residual dermal ridges) was significantly associated with increased perinatal mortality.

Animals↗

PubMed1988

Use of the automatic external defibrillator in the management of out-of-hospital cardiac arrest.

The automatic external defibrillator is a simple device that can be used by nonprofessional rescuers to treat cardiac arrest. In 1287 consecutive patients with out-of-hospital cardiac arrest, we assessed the results of initial treatment with this device by firefighters who arrived first at the scene, as compared with the results of standard defibrillation administered by paramedics who arrived slightly after the firefighters. Of 276 patients who were initially treated by firefighters using the automatic defibrillator, 84 (30 percent) survived to hospital discharge (expected rate according to a logistic model, 17 percent; P less than 0.001), as compared with 44 (19 percent) of 228 patients when fire-fighters delivered only basic cardiopulmonary resuscitation and the first defibrillation was performed after the arrival of the paramedic team. Few patients with conditions other than ventricular fibrillation survived. In a multivariate analysis of characteristics that influenced survival after ventricular fibrillation, a better survival rate was related to a witnessed collapse (odds ratio, 3.9; 95 percent confidence interval, 2.0 to 7.6), younger age (odds ratio, 1.2; 95 percent confidence interval, 1.0 to 1.4), the presence of "coarse" (higher-amplitude) fibrillation (odds ratio, 4.2; 95 percent confidence interval, 1.6 to 11.0), a shorter response time for paramedics (odds ratio, 1.4; 95 percent confidence interval, 1.0 to 2.1), and initial treatment by firefighters using an automatic external defibrillator (odds ratio, 1.8; 95 percent confidence interval, 1.1 to 2.9). These findings support the widespread use of the automatic external defibrillator as an important part of the treatment of out-of-hospital cardiac arrest, although the overall impact of the use of this device on community survival rates is still uncertain.

Aged↗

PubMed1986

Intolerance and ineffectiveness of mexiletine in patients with serious ventricular arrhythmias.

Fifty-one patients were treated with mexiletine over 10.4 +/- 16 months. The clinical arrhythmia in 25 (49%) was ventricular fibrillation (VF), 11 (22%) had sustained ventricular tachycardia (VT), and 15 (29%) had symptomatic nonsustained VT. Ischemic heart disease was present in 33 patients (66%), cardiomyopathy in nine (17%), and valvular or congenital heart disease in nine (17%). Only six (12%) remain on the drug. Arrhythmias recurred in 21 patients (41%): seven (14%) with VF, three (5%) with sustained VT, and 11 (22%) with symptomatic nonsustained VT. Intolerable side effects occurred in another 17 (33%). Seven patients (14%) died from nonarrhythmic-related deaths while taking mexiletine. Mexiletine was combined with a conventional type IA antiarrhythmic agent in 25 patients (49%). In 12 of these 25 patients (48%), ventricular arrhythmias recurred. These findings were not significantly different from those of the group treated with mexiletine alone, where arrhythmias recurred in 9 of 26 patients (35%) (p = NS). Thus mexiletine, alone or in combination with a type IA antiarrhythmic agent, has limited clinical utility in patients with life-threatening ventricular arrhythmias.

Cardiac Pacing, Artificial↗

PubMed1982

Nonhuman primate dermatoglyphics: implications for human biomedical research.

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Animals↗

PubMed1980

Ossification in the hand and foot of the pigtail macaque (Macaca nemestrina). II. Order of appearance of centers and variability in sequence.

The order of appearance of the carpals, tarsals and secondary epiphyseal centers in the hand-wrist and foot-ankle regions of the fetal and infant pigtail macaque (Macaca nemestrina) was reconstructed using a cross-sectional sample of 127 animals and a longitudinal one of 14 animals. Comparison of the most common sequence in the monkey with that described in the human studies showed major interspecific differences in the order of appearance of several groups of centers, particularly those involving the thumb and great toe. The monkey displays a degree of sequence variability equivalent to that documented by the human longitudinal data, with certain centers markedly variable in timing and/or order of appearance. The evidence from related animals suggests a strong genetic component underlying some of the variable sequences observed, as has been reported in the human studies. The demonstrated variability in both timing and sequence precludes the use of specific centers in the determination of gestational age in fetuses of unknown conception date.

Animals↗