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Safety and efficacy of noninvasive cardiac pacing
Abstracts in this issue were prepared by residents in the Denver General/St Anthony's/St Joseph Hospitals Emergency Medicine Residency Program.
ABSTRACTS Vincent J Markovchick, MD, FACEP Co-Editor Emergency Medical Services
Harvey W Meislin, MD, FACEP Co-Editor Chief, Section of E m e r g e n c y M e d i c i n e University of A r i z o n a College of M e d i c i n e
Denver General Hospital
nary perfusion pressure in five of the eight dogs. The potential clinical implications of this study are that the rise in WC pressure during CPR is secondary to right heart reflux rather than arterial to venous inflow. A palpable femoral "pulse" during CPR is as likely to be of venous origin as arterial. Subdiaphragmatic intravenous drug administration may not be an effective route due to the "to and fro" movement of subdiaphragmatic venous blood. Tom Drake, MD
CARDIAC PACING, NONINVASIVE
Safety and efficacy of noninvasive cardiac pacing Falk RH, Zoil PM, Zoll RH N Engl J Med 309:1166-1168 Nov 1983
Noninvasive cardiac pacing was tested in 16 normal male volunteers and 15 patients with sinus node dysfunction. The device contained an electrocardiac monitor attached in the standard manner to facilitate fixed-rate or demand mode to the anterior and larger posterior pacing electrodes. The pacemaker stimulus was a 4-ms impulse capable of delivering up to 140 mA, 180 times a minute. The m a x i m u m time of pacing was 15 minutes in normal subjects and 30 minutes in patients. Thirteen of the 14 patients and 15 of the 16 normal subjects tolerated electrical stimulation to pacing threshold. One patient, with severe cardiomyopathy, did not pace even at m a x i m u m pacing stimulus. The mean current necessary for pacing was 54 mA in normal subjects and 56 mA in patients. The pacing threshold for patients with hemodynamically significant bradycardia was higher (78 mA) than for those without hemodynamic impairment (51 mA). One normal subject and one patient requested discontinuation of stimulation at 60 mA because of discomfort. No atrial or ventricular irritability was noted. Philip L Henneman, MD
CPR, WITH ABDOMINAL BINDING
Hemodynamic effects of continuous abdominal binding during cardiac arrest and resuscitation Niemann JT, Rosborough JP, Ung S, et al Am J Cardiol 53:269-274 Jan 1984
The effects of abdominal b i n d i n g on various hemodynamic parameters in eight mongrel dogs were studied. Carotid artery and inferior vena caval flow probes and cineradiography were used to observe the magnitude and direction of blood flow. CPR with abdominal binding significantly increased systolic aortic, right atrial, and inferior vena cava (IVC) pressures and common carotid flow as compared with CPR without binding. Also observed was a decreased net IVC flow during abdominal binding, with cineangiograms showing a preferential cephalad flow. The major adverse effect of binding appeared to be a decrease in c o r o 13:7 July 1984
ACTIVATED CHARCOAL, THEOPHYLLINE CLEARANCE; THEOPHYLLINE, EFFECT OF ACTIVATED CHARCOAL
Increased serum theophylline clearance with orally administered activated charcoal Mahutte CK, True RJ, Michiels TM, et al Am Rev Respir Dis 128:820-822 1983
This study was done to determine the effect of orally administered activated charcoal on the clearance of intravenously administered theophylline. Eight h u m a n volunteers acted as their own controls. On two separate days they were loaded with theophylline (8 mg/kg W) and then received either no additional treatment or activated charcoal (30 g orally every two hours, four times). In the charcoal treatment group, serum theophylline half-life was decreased and its clearance was increased by a factor of two. The mechanism of action for the observed effect was presumed to be gastrointestinal (GI) absorption of aminophyUine by activated charcoal in the GI tract. John M Wogan, MD ENDOTRACHEAL INTUBATION
Field endotracheal intubation by paramedical personnel: Success rates and complications Stewart RD, Paris PM, Winter PM, et al Chest 85:341-345 Mar 1984
One hundred thirty mobile intensive care unit paramedics of the Department of Emergency Medical Services in the city of Pittsburgh were trained in the technique of direct laryngoscopic endotracheal intubation. Seven hundred seventy-nine patients found in cardiac arrest or in deep coma without a gag reflex, on whom direct laryngoscopic
Annals of Emergency Medicine
570/125
ABSTRACTS Vincent J Markovchick, MD, FACEP Co-Editor Emergency Medical Services
Harvey W Meislin, MD, FACEP Co-Editor Chief, Section of E m e r g e n c y M e d i c i n e University of A r i z o n a College of M e d i c i n e
Denver General Hospital
nary perfusion pressure in five of the eight dogs. The potential clinical implications of this study are that the rise in WC pressure during CPR is secondary to right heart reflux rather than arterial to venous inflow. A palpable femoral "pulse" during CPR is as likely to be of venous origin as arterial. Subdiaphragmatic intravenous drug administration may not be an effective route due to the "to and fro" movement of subdiaphragmatic venous blood. Tom Drake, MD
CARDIAC PACING, NONINVASIVE
Safety and efficacy of noninvasive cardiac pacing Falk RH, Zoil PM, Zoll RH N Engl J Med 309:1166-1168 Nov 1983
Noninvasive cardiac pacing was tested in 16 normal male volunteers and 15 patients with sinus node dysfunction. The device contained an electrocardiac monitor attached in the standard manner to facilitate fixed-rate or demand mode to the anterior and larger posterior pacing electrodes. The pacemaker stimulus was a 4-ms impulse capable of delivering up to 140 mA, 180 times a minute. The m a x i m u m time of pacing was 15 minutes in normal subjects and 30 minutes in patients. Thirteen of the 14 patients and 15 of the 16 normal subjects tolerated electrical stimulation to pacing threshold. One patient, with severe cardiomyopathy, did not pace even at m a x i m u m pacing stimulus. The mean current necessary for pacing was 54 mA in normal subjects and 56 mA in patients. The pacing threshold for patients with hemodynamically significant bradycardia was higher (78 mA) than for those without hemodynamic impairment (51 mA). One normal subject and one patient requested discontinuation of stimulation at 60 mA because of discomfort. No atrial or ventricular irritability was noted. Philip L Henneman, MD
CPR, WITH ABDOMINAL BINDING
Hemodynamic effects of continuous abdominal binding during cardiac arrest and resuscitation Niemann JT, Rosborough JP, Ung S, et al Am J Cardiol 53:269-274 Jan 1984
The effects of abdominal b i n d i n g on various hemodynamic parameters in eight mongrel dogs were studied. Carotid artery and inferior vena caval flow probes and cineradiography were used to observe the magnitude and direction of blood flow. CPR with abdominal binding significantly increased systolic aortic, right atrial, and inferior vena cava (IVC) pressures and common carotid flow as compared with CPR without binding. Also observed was a decreased net IVC flow during abdominal binding, with cineangiograms showing a preferential cephalad flow. The major adverse effect of binding appeared to be a decrease in c o r o 13:7 July 1984
ACTIVATED CHARCOAL, THEOPHYLLINE CLEARANCE; THEOPHYLLINE, EFFECT OF ACTIVATED CHARCOAL
Increased serum theophylline clearance with orally administered activated charcoal Mahutte CK, True RJ, Michiels TM, et al Am Rev Respir Dis 128:820-822 1983
This study was done to determine the effect of orally administered activated charcoal on the clearance of intravenously administered theophylline. Eight h u m a n volunteers acted as their own controls. On two separate days they were loaded with theophylline (8 mg/kg W) and then received either no additional treatment or activated charcoal (30 g orally every two hours, four times). In the charcoal treatment group, serum theophylline half-life was decreased and its clearance was increased by a factor of two. The mechanism of action for the observed effect was presumed to be gastrointestinal (GI) absorption of aminophyUine by activated charcoal in the GI tract. John M Wogan, MD ENDOTRACHEAL INTUBATION
Field endotracheal intubation by paramedical personnel: Success rates and complications Stewart RD, Paris PM, Winter PM, et al Chest 85:341-345 Mar 1984
One hundred thirty mobile intensive care unit paramedics of the Department of Emergency Medical Services in the city of Pittsburgh were trained in the technique of direct laryngoscopic endotracheal intubation. Seven hundred seventy-nine patients found in cardiac arrest or in deep coma without a gag reflex, on whom direct laryngoscopic
Annals of Emergency Medicine
570/125