Biomedical subjects

C Fahrenbruch

Publications and source records attributed to C Fahrenbruch.

8 recordsLinked to original sources

PubMed2001

Cardiac arrest in medical and dental practices: implications for automated external defibrillators.

BACKGROUND: To determine the need for placing automated external defibrillators (AEDs) in medical and dental practices, we identified cardiac arrests at these locations. METHODS: Locations of cardiac arrest were abstracted from Emergency Medical Services data from January 1, 1990, through December 31, 1996. We calculated the annual incidence of cardiac arrest per type of practice. RESULTS: There were 142 cardiac arrests in medical or dental practices. Dialysis centers had a relatively high incidence of cardiac arrest (>/=0.746 per practice annually). Cardiology, internal and family medicine, and urgent care centers had a medium incidence (>/=0.01 per practice annually). All other medical and dental practices had a low incidence (</=0.002 annually). CONCLUSIONS: Placement of 779 AEDs in the high- and medium-incidence practices would have provided treatment for 112 patients with cardiac arrest in 7 years. To provide for the 16 cardiac arrests in low-incidence practices, an additional 1928 AEDs would be required.

Age Distribution↗

PubMed1998

Public locations of cardiac arrest. Implications for public access defibrillation.

BACKGROUND: The purpose of this study was to describe the public locations of cardiac arrest and to estimate the annual incidence of cardiac arrest per site to determine optimal placement of automatic external defibrillators (AEDs). This was a retrospective cohort study. METHODS AND RESULTS: Locations of cardiac arrest were abstracted from data collected by emergency medical service programs in Seattle and King County, Washington, from January 1, 1990, through December 31, 1994. Types of commercial and civic establishments were tallied and grouped into 23 location categories consistent with Standard Industrial Codes, and the number of sites within each location category was determined. With the addition of "public outdoors" and "automobiles" as categories, there were 25 location categories. During the study period, 7185 arrests occurred, 1130 (16%) of which were in public locations. An annual incidence of cardiac arrest per site was calculated. Ten location categories with 172 sites were identified as having a higher incidence of cardiac arrest (> or = .03 per year per site). Thirteen location categories had a lower incidence of arrest (< or = .01 per year per site). There were approximately 71,000 sites within these categories. CONCLUSIONS: Placement of 276 AEDs in the 172 higher-incidence sites would have provided treatment for 134 cardiac arrest patients in a 5-year period, 60% of whom were in ventricular fibrillation. We estimate between 8 and 32 lives could be saved in 5 years. To cover the remaining 347 arrests occurring in public in a 5-year period, defibrillators would have to be placed in 71,000 sites, not including outdoors and automobiles. Placement of AEDs in public locations can be guided by the site-specific incidence of arrest.

Electric Countershock↗

PubMed1995

Out-of-hospital ventricular fibrillation in children and adolescents: causes and outcomes.

STUDY OBJECTIVE: To compare causes and outcomes of patients younger than 20 years with an initial rhythm of ventricular fibrillation versus asystole and pulseless electrical activity. DESIGN: Retrospective cohort study. SETTING: Urban/suburban prehospital system. PARTICIPANTS: Pulseless, nonbreathing patients less than 20 years who underwent out-of-hospital resuscitation. Patients with lividity or rigor mortis or who were less than 6 months old and died of sudden infant death syndrome were excluded. RESULTS: Ventricular fibrillation was the initial rhythm in 19% (29 of 157) of the cardiac arrests. Rhythm assessment was performed by the first responder in only 44% (69 of 157) of patients. All three rhythm groups were similar in age distribution, frequency of intubation (96%), and vascular access (92%); 93% of ventricular fibrillation patients were defibrillated. The causes of ventricular fibrillation were distributed evenly among medical illnesses, overdoses, drownings, and trauma, only two patients had congenital heart defects. Seventeen percent were discharged with no or mild disability, compared with 2% of asystole/pulseless electrical activity patients (P = .003). CONCLUSION: Ventricular fibrillation is not rare in child and adolescent prehospital cardiac arrest, and these patients have a better outcome than those with asystole or pulseless electrical activity. Earlier recognition and treatment of ventricular fibrillation might improve pediatric cardiac arrest survival rates.

Adolescent↗

PubMed1987

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)

Algorithms↗

PubMed1986

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.

Allied Health Personnel↗

PubMed1986

Considerations for improving survival from out-of-hospital cardiac arrest.

Since the implementation of a paramedic system in Seattle, yearly survival rates from out-of-hospital cardiac arrest due to ventricular fibrillation have averaged 25% without any significant increase over the years. Outcome for cardiac arrest associated with other rhythms has been poor: when asystole was the first rhythm recorded, only 1% of patients survived; when electromechanical dissociation was initially present, only 6% survived. For cases of electromechanical dissociation, neither the type of rhythm nor the rate appear to influence outcome. Survival from ventricular fibrillation can be improved by shortening the delay to initiation of CPR and to defibrillation. When outcome in 244 witnessed arrests was related to the times to beginning CPR and to initial defibrillation, mortality increased 3% each minute until CPR was begun and 4% a minute until the first shock was delivered. New strategies that minimize delays appear to have the greatest promise for improving survival after cardiac arrest.

Ambulances↗

PubMed1986

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.

Aged↗

PubMed1979

Supernumerary epiphyses in the macaque (Macaca nemestrina).

The frequency, age distribution and development of supernumerary epiphyses in the hand and foot were radiographically documented in 98 macaque fetuses and infants. Extra epiphyses were observed only on distal metacarpal 1 and metatarsal 1, and were present in 15% of a cross-sectional sample and 20% of a longitudinal sample. They appeared coincidentally with the ossification of other secondary epiphyses of the hand and foot. Development of extra epiphyses in this species seems to be a normal phenomenon.

Animals↗