(Circulation. 2000;101:1743.)
© 2000 American Heart Association, Inc.
Basic Science Reports |
"Bystander" Chest Compressions and Assisted Ventilation Independently Improve Outcome From Piglet Asphyxial Pulseless "Cardiac Arrest"
From the University of Arizona Sarver Heart Center (R.A.B., R.W.H., K.B.K., G.A.E.); Department of Pediatrics, Steele Memorial Children’s Research Center (R.A.B.); and Department of Medicine (R.W.H., K.B.K., G.A.E.), The University of Arizona College of Medicine, 1501 N Campbell Ave, Tucson, AZ 85724.
 |
Abstract |
|---|
 Top Abstract IntroductionMethodsResultsDiscussionReferences |
|---|
Background—Bystander cardiopulmonary resuscitation (CPR) without assisted ventilation may be as effective as CPR with assisted ventilation for ventricular fibrillatory cardiac arrests. However, chest compressions alone or ventilation alone is not effective for complete asphyxial cardiac arrests (loss of aortic pulsations). The objective of this investigation was to determine whether these techniques can independently improve outcome at an earlier stage of the asphyxial process.
Methods and Results—After induction of anesthesia, 40 piglets (11.5±0.3 kg) underwent endotracheal tube clamping (6.8±0.3 minutes) until simulated pulselessness, defined as aortic systolic pressure <50 mm Hg. For the 8-minute "bystander CPR" period, animals were randomly assigned to chest compressions and assisted ventilation (CC+V), chest compressions only (CC), assisted ventilation only (V), or no bystander CPR (control group). Return of spontaneous circulation occurred during the first 2 minutes of bystander CPR in 10 of 10 CC+V piglets, 6 of 10 V piglets, 4 of 10 CC piglets, and none of the controls (CC+V or V versus controls, P<0.01; CC+V versus CC and V combined, P=0.01). During the first minute of CPR, arterial and mixed venous blood gases were superior in the 3 experimental groups compared with the controls. Twenty-four-hour survival was similarly superior in the 3 experimental groups compared with the controls (8 of 10, 6 of 10, 5 of 10, and 0 of 10, P<0.05 each).
Conclusions—Bystander CPR with CC+V improves outcome in the early stages of apparent pulseless asphyxial cardiac arrest. In addition, this study establishes that bystander CPR with CC or V can independently improve outcome.
Key Words: cardiopulmonary resuscitation • heart arrest • ventilation • asphyxia • pediatrics
|
Introduction |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
Bystander cardiopulmonary resuscitation (CPR) improves survival from prehospital ventricular fibrillatory (VF) cardiac arrest, even though it is only a bridge until defibrillation.1 2 3 For asphyxial cardiac arrests, bystander CPR can be definitive therapy.1 Nevertheless, in 2 recent studies, there were no attempts at bystander CPR for 74% and 61% of children with prehospital cardiac arrests.4 5
Single-rescuer bystander CPR includes mouth-to-mouth rescue breathing and chest compressions (CC), complex psychomotor tasks that are difficult to teach, learn, remember, and perform.1 6 Animal and clinical investigations suggest that bystander CPR without assisted ventilation (ie, no mouth-to-mouth rescue breathing) may be as effective as CPR with assisted ventilation for VF cardiac arrests.2 3 7 8 9 10 11 12 However, rescue breathing is considered especially important for children in cardiac arrest because a respiratory problem so often initiates the event and VF is relatively uncommon.1 4 13 In a recent swine study of simulated pediatric asphyxial cardiac arrest (no aortic pulsations), chest compressions plus assisted ventilation (CC+V) resulted in markedly superior outcome compared with no "bystander" CPR or CC without (V).14
Clinical and epidemiological data suggest that some children with apparent cardiac arrest respond to bystander CPR with CC alone or rescue breathing alone.2 15 16 17 Perhaps these patients are apneic, unresponsive, and apparently pulseless but not yet in complete cardiac arrest. They may have had inadequate blood pressure without total loss of aortic pulsation (asphyxial shock).18
The purpose of this investigation was to determine whether CC alone and V alone (V) can independently improve outcome at an early stage of apparent asphyxial cardiac arrest (systolic BP<50 mm Hg) in piglets. In a previous piglet study, CC and V did not improve outcome from complete asphyxial cardiac arrest (no aortic pulsations).14 Our hypotheses were that bystander CPR with CC or V would be superior to no bystander CPR, and each would be inferior to CC+V earlier in the asphyxial process.
|
Methods |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
Animal Preparation
Experimental protocols were approved by The University of Arizona Institutional Animal Care and Use Committee and followed the guidelines of the American Physiological Society. Healthy 2- to 3-month-old domestic piglets were subjected to masked anesthesia with isoflurane, followed by oral endotracheal intubation. They were mechanically ventilated with a volume-limited, time-cycled Harvard ventilator (model 661; Harvard Apparatus, Inc) on a mixture of room air and titrated isoflurane (0.5% to 1.5%). The tidal volume was initially set at 15 mL/kg and ventilator rate at 12 breaths per minute; ventilator settings were adjusted to maintain end-tidal carbon dioxide at 35 to 40 mm Hg (4.7 to 5.3 kPa).
After a surgical plane of anesthesia had been achieved, introducer sheaths were placed in the right external jugular vein, right carotid artery, and left external jugular vein by cutdown technique. High-fidelity, solid-state, micromanometer-tipped Millar catheters were advanced through the carotid artery and external jugular vein into thoracic locations. A fluid-filled balloon-tipped flotation catheter was placed in the main pulmonary artery through the right external jugular introducer sheath. Catheter placements were performed under fluoroscopic guidance.
Measurements
Right atrial and thoracic aortic pressure waveforms, as well as
ECG and end-tidal PCO2 measurements
(model 47210A, Hewlett Packard), were continuously monitored and
recorded on the 4-channel Gould ES1000 recorder throughout the
experiment until the 1-hour simulated intensive care unit period ended.
Coronary perfusion pressure during CPR was calculated by
subtracting right atrial relaxation (middiastolic) pressure
from simultaneous aortic relaxation pressure at a single
point during 3 consecutive compression-relaxation cycles.
Arterial blood gas specimens were obtained from the
thoracic aorta and mixed venous specimens from the main
pulmonary artery at baseline (before cardiac arrest) and 1
minute after cardiac arrest. Oxygen saturation,
PCO2,
PO2, pH, and hemoglobin were measured
with a blood gas analyzer (IL-1306 with model 482 co-oximeter,
Instrumentation Laboratories).
Experimental Protocol
After baseline data were collected, the endotracheal tube was
clamped and the piglet was asphyxiated until simulated pulselessness,
as defined by an aortic systolic pressure <50 mm Hg
(Figure
). For the 8-minute simulated
bystander CPR period, animals were randomly assigned to group 1, chest
compressions and simulated mouth-to-mouth ventilation (CC+V); group 2,
chest compressions only (CC); group 3, simulated mouth-to-mouth
ventilation only (V); or group 4, no bystander CPR (control group). CC
plus simulated mouth-to-mouth ventilation was provided in a manner
consistent with standard single-rescuer CPR for children as
described by the American Heart Association (AHA).1 This
included ventilation with a simulated rescuer exhaled gas mixture
(FIO2 0.17 and
FICO2 0.04)19 for 2
breaths followed by 15 manual CCs at a rate of 100 per minute, repeated
sequentially. The research technician providing the manual CC was
blinded to end-tidal carbon dioxide and vascular pressure measurements
during CPR. He compressed the piglet’s chest 
33% of the
anteroposterior diameter. CCs alone were provided manually at a
metronome-guided rate of 100 per minute after the endotracheal tube was
removed (when "pulseless cardiac arrest" was determined).
Ventilation alone was provided as a simulated expired gas mixture
(FIO2 0.17 and
FICO2 0.04), delivered via
bag-valve–endotracheal tube at 12 to 15 breaths per minute. For the
control group, the endotracheal tubes remained clamped, and no
ventilation or CCs were provided during this bystander CPR period. The
experimental bystander CPR technique was discontinued when evidence of
successful resuscitation occurred, such as spontaneous respirations,
vigorous motor activity, and substantial increases in the aortic blood
pressure. Otherwise, the bystander CPR technique was continued
throughout the simulated bystander CPR period.
|
For animals that did not attain return of spontaneous circulation
(ROSC) during the 8-minute bystander CPR period, full advanced life
support was provided as if the paramedic unit had arrived at the scene.
All CC piglets without ROSC underwent endotracheal intubation during
the last minute of the bystander CPR period and were then ventilated
with 100% oxygen beginning at 8 minutes of CPR. CCs were provided at a
rate of 100 per minute and rescue breaths at a rate of 12 to 15 per
minute. Intravenous epinephrine (0.02 mg/kg) was
administered 2 minutes after the simulated paramedic team arrived and
was repeated every 3 minutes, as necessary. The 2-minute interval is
consistent with the amount of time for a typical paramedic team
to obtain intravenous access.10 The
epinephrine dose of 0.02 mg/kg was administered rather than the
AHA-recommended dose of 0.01 mg/kg because of its established use in
swine experiments.7 9 10 11 12 When VF occurred, defibrillation
was attempted with 50 J. If unsuccessful, the second defibrillation
attempt was also with 50 J, and the third and subsequent attempts were
with 100 J. ROSC was defined as unassisted aortic pulse with a
systolic blood pressure >50 mm Hg and pulse pressure
>20 mm Hg for 
1 minute.
All successfully resuscitated animals were supported aggressively for 1 hour in a simulated intensive care setting. Systolic blood pressure was maintained at >80 mm Hg with dopamine and/or volume administration as clinically indicated. All piglets received normal saline 10 mL/kg IV during the intensive care period. Ventricular arrhythmias were treated with electroshocks or lidocaine as necessary. Mechanical ventilation was provided with 100% oxygen and adjusted to obtain an end-tidal carbon dioxide of 30 to 40 mm Hg (4.0 to 5.3 kPa). Recurrent cardiac arrest was treated with standard advanced life support according to the AHA decision trees. Throughout the intensive care period, isoflurane was administered as necessary to maintain adequate analgesia and anesthesia. At the end of 1 hour, all animals were weaned off pharmacological support, ventilatory support, and anesthesia and were transferred to observation cages for the next 24 hours.
Outcome and Neurological Evaluation
Survival and neurological status were evaluated at 24 hours
after the initial cardiac arrest. To provide objective neurological
evaluation, swine cerebral performance categories were
assessed.7 9 10 11 12 Briefly, swine cerebral
performance category is a global assessment of neurological
function. Category 1 was assigned to piglets that appeared normal on
the basis of level of consciousness, gait, feeding behavior, response
to an approaching human, and response to human restraint. Category 2,
mildly abnormal, was assigned when the piglets had subtle dysfunction
with regard to these characteristics. Category 3, severely disabled,
referred to more severe dysfunction, such as inability to stand, walk,
or eat. Category 4, vegetative state or deep coma, referred to piglets
with minimal response to noxious stimuli. Category 5 referred to
animals with no response to their environment. Categories 1 and 2 were
considered good neurological outcome. After the 24-hour evaluation,
survivors were killed by infusion of pentobarbital sodium/phenytoin
sodium.
Data Analysis
Systolic and diastolic aortic pressures,
right atrial pressures, and ECGs were collected from the graphic
records at prearrest baseline, every 2 minutes after endotracheal
tube clamping (before cardiac arrest), and during the simulated
bystander CPR period. Bystander CPR hemodynamic data
were excluded after animals had return of spontaneous circulation.
Continuous variables such as blood pressures, coronary perfusion pressures, and blood gas analyses were evaluated by ANOVA. For all variables with significant differences by ANOVA, post hoc comparisons were evaluated by Fisher’s protected least significant difference test. Comparisons of blood pressures and blood gases during bystander CPR between the CC and CC+V groups were also evaluated by unpaired Student’s t test because the available data from the other 2 groups were not comparable physiologically owing to absence of CC. Continuous variables are described as mean±SEM. Comparisons of discrete variables, such as rate of return of spontaneous circulation, 1-hour intensive care unit survival, 24-hour survival, and good neurological outcome were evaluated by Fisher’s exact test.
|
Results |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
Forty animals were studied (weight, 11.5±0.3 kg). The 4 groups did not differ with respect to baseline weights, hemodynamics, or hemoglobin concentrations (Table 1
). Baseline arterial
and mixed venous PO2,
SO2, pH, and
PCO2 were also not different among
the 4 groups (Table 2).
|
|
The mean time interval from endotracheal tube clamping until simulated
pulselessness was 6.8±0.3 minutes and did not differ among the groups
(Figure
). Thirty-nine of the 40 animals exhibited pulseless electrical
activity with bradycardia or sinus rhythm at the time pulselessness was
declared. One animal had ventricular
tachycardia; none had VF. The rhythm deteriorated to VF in
17 of 40 piglets at some point during the experiment. Thirteen of the
animals went into VF during the bystander period (4 CC, 3 V, and 6
controls); 2 of these 13 converted to asystole before simulated arrival
of emergency medical services. Eleven of the 40 (27%) were in VF as
the "paramedics" arrived. An additional 4 piglets went into VF
during the paramedic resuscitation. Only 1 of the 17 piglets with VF at
any time during the experiment survived for 24 hours, compared with 19
of 23 that did not have VF, P<0.001.
After 1 minute of the bystander CPR period, arterial and
mixed venous PO2,
SO2,
PCO2, and pH were markedly better in
the 3 experimental groups than the control group (Table 2).
Similarly, the hemodynamic profiles (aortic blood
pressures and coronary perfusion pressures) were generally
superior in the CC+V and CC groups compared with the V and control
groups during the first 30 seconds of CPR (Table 3). The aortic compression
(systolic) pressures in the CC+V and CC groups did not differ
during the initial 30 seconds of CPR (before the CC+V piglets attained
return of spontaneous circulation [ROSC]), suggesting that the
force of compressions was comparable in the 2 groups.
|
The important outcome data are in Table 4. Most of the animals attained ROSC. All
of the CC+V animals were successfully resuscitated during the first 2
minutes of the bystander period, as were nearly half of the animals in
each of the other 2 experimental groups. All piglets that attained ROSC
during the bystander period of this experiment did so within the first
2 minutes. Eighteen of the 20 piglets with ROSC during the first 2
minutes of bystander CPR survived for 24 hours, compared with only 1 of
20 piglets that did not attain ROSC during the bystander CPR period,
P<0.001. Each of the 3 experimental groups had better
survival rates than the control group. Both CC+V and V had improved
24-hour good neurological survival compared with the control group, and
there was a similar trend toward improvement in the CC group as well.
The rate of ROSC during the bystander CPR period was superior in the
CC+V group to that in the combined CC and V groups (10 of 10 versus 10
of 20, P=0.01). There was a nonsignificant tendency toward
superior good neurological survival rate in the CC+V group compared
with the combined CC and V groups (8 of 10 versus 10 of 20,
P=0.24).
|
Twenty piglets attained ROSC within 2 minutes of bystander CPR; 18 survived 24 hours, 17 with good neurological outcome. Six piglets did not attain ROSC until after paramedic arrival; 5 did not survive 24 hours. Of the 26 piglets with ROSC, 7 did not survive 24 hours. Four of these piglets were from the control group; 2 died of progressive cardiorespiratory failure <1 hour after the ICU period, and the other 2 were in severe cardiorespiratory distress and severely neurologically impaired by then. One of the 6 with ROSC from the CC group was similarly neurologically impaired, exhibited moderate cardiorespiratory distress <1 hour after the ICU period, and did not survive 24 hours. Two animals from the CC+V group inexplicably died before 24 hours despite apparent cardiorespiratory stability and good neurological status (ie, alert, walking, and eating) 2 hours after ROSC.
Nine of the 10 CC+V piglets, 4 of 10 CC piglets, 6 of 10 V piglets, and 0 of 10 control animals were walking, drinking, and acting nearly normal within 2 hours of the pulseless arrest (ie, good neurological outcome at 2 hours). Among piglets that survived for 2 hours after ROSC, 17 of 19 with good neurological outcome at that time survived 24 hours with good neurological outcome (2 died), yet only 1 of 5 with bad neurological status at 2 hours attained good 24-hour neurological outcome, P<0.01.
Difficulty with resuscitation and ICU management was further estimated by comparing the 4 groups in terms of number of epinephrine doses during resuscitation and the need for dopamine after resuscitation. Because all of the CC+V piglets and approximately half of the CC and V piglets had return of spontaneous circulation during the bystander CPR period, all 3 experimental groups needed fewer epinephrine doses than the control group (0.2±0.2 versus 1.3±0.5 versus 1.2±0.5 versus 2.8±0.4 doses, respectively, P<0.001). Dopamine administration did not differ among the 4 groups (1 of 10 CC+V, 1 of 10 CC, 0 of 10 V, and 2 of 10 controls).
|
Discussion |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
This study of simulated bystander CPR in a swine model of pediatric asphyxial pulseless cardiac arrest establishes that V alone or CC alone can independently improve outcome at this stage of the asphyxial process. Both techniques also improved arterial and mixed venous blood gases during the first minute of CPR compared with the control group. Furthermore, CC+V (standard single-rescuer bystander CPR) led to superior initial successful resuscitation rates (ROSC during bystander CPR) compared with V and CC.
This study is consistent with prehospital pediatric cardiac arrest experiences. Outcomes are dismal when the child is still in cardiac arrest by the time paramedics arrive, but excellent outcomes are typical when the child is successfully resuscitated before paramedic arrival.4 5 13 15 16 17 20 21 22 23 24 Successful resuscitation techniques have included mouth-to-mouth rescue breathing alone, CC alone, and CC plus mouth-to-mouth rescue breathing; however, authors have retrospectively questioned whether these patients needed resuscitation.2 5 15 16 This controlled swine study demonstrates that such bystander CPR techniques can result in prompt successful resuscitation during sufficiently severe asphyxia that resuscitation is needed.
A previous swine asphyxial cardiac arrest investigation established that CC+V improves outcome after asphyxial cardiac arrest with absence of aortic pulsations compared with CC, V, or no bystander CPR for 8 minutes.14 The experimental design was essentially identical to the present investigation except that the animals’ asphyxia was continued until complete loss of aortic pulsations, a later phase in the asphyxial process (8.9±0.4 minutes of endotracheal tube clamping versus 6.8±0.3 minutes in the present study). The severe hypoxemia and acidosis with resultant severe cardiac and neurological insults limited the effectiveness of CC or V in that study. However, earlier in the asphyxial process (the present study), CC and V are each independently more effective than no bystander CPR.
In contrast to these asphyxial studies, simulated bystander CPR with CC
has been as effective as CC+V in clinically relevant animal models of
fibrillatory cardiac arrests.7 8 9 10 11 12 Those studies included
brief untreated cardiac arrest intervals (30 seconds and 2 minutes)
with excellent outcomes (90% to 100% survival rates) and longer
untreated cardiac arrest intervals (5 minutes) with 50% survival
rates.
Consistent with the VF animal studies is a prospective uncontrolled investigation of prehospital bystander CPR (mostly adults).2 3 Long-term survival was comparable among those treated with good-quality CC alone (17 of 116, or 15%) and those treated with good-quality CC plus mouth-to-mouth ventilation (71 of 443, or 16%). The outcomes were superior with either of these techniques compared with those receiving no CPR (123 of 2055 survival, or 6%), P<0.001.
Because oxygenation and ventilation are clearly important for survival from fibrillatory cardiac arrest,25 26 why is assisted ventilation not necessary in VF models, yet quite important in asphyxial models? Immediately after an acute fibrillatory cardiac arrest, aortic oxygen and carbon dioxide concentrations do not vary from the prearrest state because there is no blood flow and aortic oxygen consumption is minimal. Therefore, when CCs are initiated, the blood flowing from the aorta to the coronary circulation provides adequate oxygenation at an acceptable pH. At that time, myocardial oxygen delivery is limited more by blood flow than oxygen content. Over the next several minutes, arterial oxygenation and pH become increasingly important for effective resuscitation.25 26 Adequate oxygenation and ventilation can continue without assisted ventilation because of chest compression–induced gas exchange and gasping ventilation during CPR.8 9 10 11 27 Assisted ventilation was not necessary in the fibrillatory arrest experiments because arterial oxygenation and pH and myocardial oxygen delivery were adequate with CC.
During asphyxia, oxygen consumption and carbon dioxide and lactate production continue for many minutes after endotracheal tube clamping before pulselessness or cardiac arrest. In addition, continued pulmonary blood flow after endotracheal tube clamping presumably depletes the pulmonary oxygen reservoir. In contrast to VF, asphyxia results in significant arterial hypoxemia and acidemia before resuscitation and worse metabolic reserve when resuscitation commences.
A potential limitation of this study is that the experimental groups received excellent CC and rescue breathing. It is unlikely that excellent CC and rescue breathing can be provided by a single rescuer in the field. Even during 2-rescuer CPR, attention to rescue breathing may be counterproductive with respect to optimal CC.12 27 These CC+V animals benefited from optimal airway management and endotracheal tube placement before cardiac arrest. Mouth-to-mouth rescue breathing in a prehospital setting is unlikely to be nearly as controlled, effective, or safe. Rescue breathing before endotracheal intubation frequently causes gastric distension, which can lead to impairment of adequate ventilation and/or aspiration of gastric contents.1 27 28 These issues tend to bias the data in favor of the CC+V group.
Our clinical experience and research data regarding CPR in children, adults, and animals suggest that most bystanders perform CC poorly.29 30 31 We believe that outcomes from clinical cardiac arrests would improve with excellent CPR technique.
In conclusion, the outcomes in this experiment are consistent with epidemiological studies of prehospital CPR for apneic, unresponsive, pulseless children. Bystander CPR improves outcome, and many of the long-term survivors are successfully resuscitated by the bystanders before the paramedics arrive. Moreover, this study establishes that CC alone or V alone can independently improve outcome in early stages of apparent pulseless asphyxial cardiac arrest. Finally, the findings from our 2 investigations of piglet pulseless cardiac arrest support the present recommendations for bystander treatment of pediatric asphyxial cardiac arrest victims: CC+V is the treatment of choice, but either alone is better than no resuscitation attempt.1 14 27
|
Acknowledgments |
|---|
This study was supported by a research grant from the American Heart Association, Southwest Desert Affiliate.
|
Footnotes |
|---|
Reprint requests to Robert A. Berg, MD, Pediatrics/3302, 1501 N Campbell Ave/PO Box 245073, Tucson, AZ 85724-5073.
Received July 1, 1999; revision received October 26, 1999; accepted November 2, 1999.
|
References |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
1. Emergency Cardiac Care Committee, and Subcommittees, American Heart Association. Guidelines for cardiopulmonary resuscitation and emergency cardiac care. JAMA. 1992;268:2172–2198.
2. Bossaert L, Van Hoeyweghen R, and the Cerebral Resuscitation Study Group. Bystander cardiopulmonary resuscitation (CPR) in out-of-hospital cardiac arrest. Resuscitation. 1989;56:S55–S69.
3. Van Hoeyweghen RJ, Bossaert LL, Mullie A, Calle P, Martens P, Buylaert WA, Delooz H, Belgian Cerebral Resuscitation Study Group. Quality and efficiency of bystander CPR. Resuscitation. 1993;26:47–52.[Medline] [Order article via Infotrieve]
4. Mogayzel C, Quan L, Graves JP, Tiedeman D, Fahrenbruch C, Herndon P. Out-of-hospital ventricular fibrillation in children and adolescents: causes and outcomes. Ann Emerg Med. 1995;125:484–491.
5. Sirbaugh PE, Pepe PE, Shook JE, Kimball KT, Goldman MJ, Ward MA, Mann DM. A prospective, population-based study of the demographics, epidemiology, management, and outcome of out-of-hospital pediatric cardiopulmonary arrest. Ann Emerg Med. 1999;33:174–184.[Medline] [Order article via Infotrieve]
6. Flint LS Jr, Billi JE, Kelly K, Mandel L, Newell L, Stapelton ER. Education in adult basic life support training programs. Ann Emerg Med. 1993;22:468–474.[Medline] [Order article via Infotrieve]
7.
Berg RA, Kern KB, Sanders AB, Otto CN, Hilwig RW, Ewy
GA. Bystander cardiopulmonary resuscitation: is ventilation
necessary? Circulation. 1993;88:1907–1915.
8.
Noc M, Weil MH, Tang W, Turner T, Fukui M. Mechanical
ventilation may not be essential for initial cardiopulmonary
resuscitation. Chest. 1995;108:821–827.
9. Berg RA, Wilcoxson D, Hilwig RW, Kern KB, Sanders AB, Otto CW, Eklund DK, Ewy GA. The need for ventilatory support during bystander CPR. Ann Emerg Med. 1995;26:342–350.[Medline] [Order article via Infotrieve]
10.
Berg RA, Kern KB, Hilwig RW, Berg MD, Sander AB, Otto
CW, Ewy GA. Assisted ventilation does not improve outcome in a porcine
model of single-rescuer bystander cardiopulmonary
resuscitation. Circulation. 1997;95:1635–1641.
11.
Berg RA, Kern KB, Hilwig RW, Ewy GA. Assisted
ventilation during "bystander" CPR in a swine acute myocardial
infarction model does not improve outcome. Circulation. 1997;96:4364–4371.
12. Kern KB, Hilwig RW, Berg RA, Ewy GA. Efficacy of chest compression-only BLS CPR in the presence of an occluded airway. Resuscitation. 1998;39:179–188.[Medline] [Order article via Infotrieve]
13. Hickey RW, Cohen DM, Strausbaugh S, Dietrich AM. Pediatric patients requiring CPR in the prehospital setting. Ann Emerg Med. 1995;25:495–501.[Medline] [Order article via Infotrieve]
14. Berg RA, Hilwig RW, Kern KB, Babar I, Ewy GA. Simulated mouth-to-mouth ventilation and chest compressions (bystander cardiopulmonary resuscitation) improves outcome in a swine model of prehospital pediatric asphyxial cardiac arrest. Crit Care Med. 1999;27:1893–1899.[Medline] [Order article via Infotrieve]
15. Nichter MA, Everett PB. Childhood near-drowning: is cardiopulmonary resuscitation always indicated? Crit Care Med. 1989;17:993–995.[Medline] [Order article via Infotrieve]
16. Friesen RM, Duncan P, Tweed WA, Bristow G. Appraisal of pediatric cardiopulmonary resuscitation. Can Med Assoc J. 1982;126:1055–1058.[Abstract]
17. Biggart MJ, Bohn DJ. Effect of hypothermia and cardiac arrest on outcome of near-drowning accidents in children. J Pediatr. 1990;117:179–183.[Medline] [Order article via Infotrieve]
18.
Paradis NA, Martin GB, Goetting MG, Rivers EP, Feingold
M, Nowak RM. Aortic pressure during human cardiac arrest:
identification of human pseudo-electromechanical dissociation.
Chest. 1992;101:123–128.
19.
Wenzel V, Idris AH, Banner MJ, Fuerst RS, Tucker KJ.
The composition of gas given by mouth-to-mouth ventilation during CPR.
Chest. 1994;106:1806–1810.
20.
Christensen DW, Jansen P, Perkin RM. Outcome and acute
care hospital costs after warm water near drowning in children.
Pediatrics. 1997;99:715–721.
21. Fiser DH, Wrape V. Outcome of cardiopulmonary resuscitation in children. Pediatric Emerg Care. 1987;3:235–238.
22.
Quan L, Wentz KR, Gore EJ, Copass MK. Outcome and
predictors of outcome in pediatric submersion victims receiving
prehospital care in King County, Washington. Pediatrics. 1990;86:586–593.
23. Kemp AM, Sibert JR. Outcome in children who nearly drown: a British Isles study. BMJ. 1991;302:931–933.
24.
Kyriacou DN, Arcinue EL, Peek C, Kraus JF. Effect of
immediate resuscitation on children with submersion injury.
Pediatrics. 1994;94:137–142.
25.
Idris AH, Becker LB, Fuerst RS, Wenzel V, Rush WJ,
Melker RJ, Orban DJ. Effect of ventilation on resuscitation in an
animal model of cardiac arrest. Circulation. 1994;90:3063–3069.
26.
Idris AH, Wenzel V, Becker LB, Banner MJ, Orban DJ.
Does hypoxia or hypercarbic acidosis independently affect
survival from cardiac arrest? Chest. 1995;108:522–528.
27.
Becker LB, Berg RB, Pepe PE, Idris AH, Aufderheide TP,
Barnes TA, Stratton SJ, Chandra NC. A reappraisal of mouth-to-mouth
ventilation during bystander-initiated cardiopulmonary
resuscitation. Circulation. 1997;96:2102–2112.
28. Berg MD, Idris AH, Berg RA. Severe ventilatory compromise due to gastric distention during CPR in a child. Resuscitation. 1998;36:71–73.[Medline] [Order article via Infotrieve]
29. Berg RA, Sanders AB, Milander MM, Tellez D, Liu P, Beyda D. Efficacy of audio-prompted rate-guidance in improving resuscitator performance of cardiopulmonary resuscitation on children. Acad Emerg Med. 1994;1:35–40.[Medline] [Order article via Infotrieve]
30.
Kern KB, Sanders AB, Raife J, Milander MM, Otto CW, Ewy
GA. A study of chest compression rates during cardiopulmonary
resuscitation in humans: the importance of rate-directed chest
compressions. Arch Intern Med. 1992;152:145–149.
31. Milander MM, Hiscok PS, Sanders AB, Kern KB, Berg RA, Ewy GA. Chest compression and ventilation rates during cardiopulmonary resuscitation: the effects of audible tone guidance. Acad Emerg Med. 1995;2:708–713.[Medline] [Order article via Infotrieve]
This article has been cited by other articles:
 |
|
 |
|
  A. A. Topjian, R. A. Berg, and V. M. Nadkarni Pediatric Cardiopulmonary Resuscitation: Advances in Science, Techniques, and Outcomes Pediatrics, November 1, 2008; 122(5): 1086 - 1098. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. R. Sayre, R. A. Berg, D. M. Cave, R. L. Page, J. Potts, and R. D. White Hands-Only (Compression-Only) Cardiopulmonary Resuscitation: A Call to Action for Bystander Response to Adults Who Experience Out-of-Hospital Sudden Cardiac Arrest: A Science Advisory for the Public From the American Heart Association Emergency Cardiovascular Care Committee Circulation, April 22, 2008; 117(16): 2162 - 2167. [Full Text] [PDF]
|
|
|
|
 |
|
 R. A. Samson, V. M. Nadkarni, P. A. Meaney, S. M. Carey, M. D. Berg, R. A. Berg, and the American Heart Association National Registry o Outcomes of in-hospital ventricular fibrillation in children. N. Engl. J. Med., June 1, 2006; 354(22): 2328 - 2339. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
American Heart Association 2005 American Heart Association (AHA) Guidelines for Cardiopulmonary Resuscitation (CPR) and Emergency Cardiovascular Care (ECC) of Pediatric and Neonatal Patients: Pediatric Basic Life Support Pediatrics, May 1, 2006; 117(5): e989 - e1004. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
The International Liaison Committee on Resuscitati The International Liaison Committee on Resuscitation (ILCOR) Consensus on Science With Treatment Recommendations for Pediatric and Neonatal Patients: Pediatric Basic and Advanced Life Support Pediatrics, May 1, 2006; 117(5): e955 - e977. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Part 3: Overview of CPR Circulation, December 13, 2005; 112(24_suppl): IV-12 - IV-18. [Full Text] [PDF]
|
|
|
|
|
|
Part 4: Adult Basic Life Support Circulation, December 13, 2005; 112(24_suppl): IV-19 - IV-34. [Full Text] [PDF]
|
|
|
|
|
|
Part 11: Pediatric Basic Life Support Circulation, December 13, 2005; 112(24_suppl): IV-156 - IV-166. [Full Text] [PDF]
|
|
|
|
|
|
Part 2: Adult Basic Life Support Circulation, November 29, 2005; 112(22_suppl): III-5 - III-16. [Full Text] [PDF]
|
|
|
|
|
|
Part 6: Pediatric Basic and Advanced Life Support Circulation, November 29, 2005; 112(22_suppl): III-73 - III-90. [Full Text] [PDF]
|
|
|
|
|
|
T. D. Valenzuela, K. B. Kern, L. L. Clark, R. A. Berg, M. D. Berg, D. D. Berg, R. W. Hilwig, C. W. Otto, D. Newburn, and G. A. Ewy Interruptions of Chest Compressions During Emergency Medical Systems Resuscitation Circulation, August 30, 2005; 112(9): 1259 - 1265. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. M. Ayoub, D. J. Brown, and R. J. Gazmuri Transtracheal Oxygenation : An Alternative to Endotracheal Intubation During Cardiac Arrest Chest, November 1, 2001; 120(5): 1663 - 1670. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. D. Mayr, V. Wenzel, W. G. Voelckel, A. C. Krismer, T. Mueller, K. G. Lurie, and K. H. Lindner Developing a Vasopressor Combination in a Pig Model of Adult Asphyxial Cardiac Arrest Circulation, October 2, 2001; 104(14): 1651 - 1656. [Abstract] [Full Text] [PDF]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||