Postgraduate Medicine
ISSN: 0032-5481 (Print) 1941-9260 (Online) Journal homepage: http://www.tandfonline.com/loi/ipgm20
Open-chest cardiac massage Michael B. Heller MD To cite this article: Michael B. Heller MD (1990) Open-chest cardiac massage, Postgraduate Medicine, 87:8, 189-194, DOI: 10.1080/00325481.1990.11704682 To link to this article: http://dx.doi.org/10.1080/00325481.1990.11704682
Published online: 17 May 2016.
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Citing articles: 1 View citing articles
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Date: 21 June 2016, At: 11:01
Open-chest cardiac massage The possible rebirth of an old procedure
Michael B. Heller, MD
Downloaded by [UQ Library] at 11:01 21 June 2016
Preview For the last 30 years, the emergency medical response to a patient in cardiac arrest has been cardiopulmonary resuscitation (CPR), incorporating closed-chest cardiac massage. However, open-chest cardiac massage predates CPR as treatment for cardiac arrest and may offer advantages in some cases. Dr Heller examines the two methods and compares their efficacy.
The universal acceptance of dosedchest cardiac massage by both the medical profession and the public sometimes makes it difficult to recall that cardiopulmonary resuscitation (CPR) as we know it was introduced only 30 years ago. Before publication in 1960 of the classic paper by Kouwenhoven and associates 1 describing the dosedchest technique, physicians performing emergency cardiac resuscitations (particularly in hospitals) primarily used open-chest cardiac massage. Although many large studies showed some remarkable results with open-chest cardiac massage, the technique was virtually abandoned, at least fur medical cardiac arrest, as the dosed-chest method became universally accepted. Enthusiasm for the new technique was so great that no comparative studies were done, and physicians have been trained in CPR for decades with no experience or knowledge of the open-chest method. Now, a combination of factors has rekindled interest in the open-
chest technique, which may soon become a preferred method in some types of medical cardiac arrest. History of cardiac resuscitation No one knows what brave soul first performed a thoracotomy to manually restart the heart; it may have been attempted in antiquity. Hakd reponed open-chest resuscitation of chloroform-induced cardiac arrest in 1874, possibly the earliest mention in the medical literature. OPEN-QIFST MASSAGE-This
technique was widely used by the turn of the century, mostly by surgeons in hospitals. Several studi~ were published, some largely skewed toward arrests during surgery. Success rates generally exceeded those recorded for the dosed-chest technique today; but the two patient populations are often not directly comparable. Stephenson and colleagues4 studied a series of 1,200 cardiac arrests in patients who were resuscitated with the open-chest technique (survival rate, 28%). His group included almost 200 pa-
VOL 87/NO 8/JUNE 1990/POSTGRADUATE MEDICINE • CARDIAC RESUSCITATION
tients resuscitated in nonsurgical settings; even this group had a survival rate of about 17%. Although these studies were inelegant by today's standards because they were retrospective and uncontrolled, there was great enthusiasm for the open-chest technique. Major complications appeared to be remarkably infrequent in patients who survived, and compared with CPR, a relative freedom from serious infection was particularly notable.5-9 A radical change occurred from the mid 1960s through the 1970s: The open-chest technique was relegated almost exclusively to emergency trauma situations or arrest during thoracotomy. Although a few adherents persisted and dramatic saves continued to be reported, the open-chest method was widely considered obsolete. QDSED-CHFSf MASSAGE-The
new technique became the officially approved method of resuscitatipn for virtually every group from the American Heart Association to the American Red Cross to the Boy Scouts. Within 15 years, 12 million Americans had been trained in CPR, and a survey indicated that almost half the adult population planned on taking a CPR course. 10 While the appeal of the dosedchest technique is perhaps understandable, the enthusiasm with which it was uncritically embraced continued 189
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The coronary vasculature is completely intrathoracic and, therefore, develops little or no pressure gradient during chest compression.
Furthermore, it was widely published that one third of the normal cardiac output could be rather routinely obtained by properly applying the technique. 12 In recent years, however, these and many other previously held beliefS concerning dosed-chest resuscitation have been shown to be false. Current resuscitation theory An era of skepticism and a general
Michael B. Heller, MD Dr Heller is associate professor, division of emergency medicine, department of medicine, University of Pittsburgh School of Medicine; associate director, Center for Emergency Medicine; and medical director, Specialized Treatment and Transport (STAT), an aeromedical service in Pittsburgh. He has a long-standing interest in resuscitation techniques.
surely must make it one of the great fads in American medical history. It is surprising how little was actually known about the mechanics of the technique, although extremely specific guidelines for administering CPR were and still are promulgated. Texts on both basic and advanced life support did and sometimes still do explain that the beneficial effects of the dosed-chest technique are due to a physical compression of the heart between the sternum and the vertebrae. 11 190
reevaluation of the usefulness of dosed-chest cardiac massage began when several groups in the early 1980s demonstrated that the heart itself has little to do with circulation during chest compression. Since the heart chambers do not fill and valves do not move during CPR, alternative explanations for the production of blood flow have appeared. 13. 15 MEOIANISM OF BLOOD FI.DW-
In general, it is now widely accepted that blood flow during chest compression is largely the result of phasic changes in intrathoracic pressure rather than pressure in the extrathoracic vessels. Furthermore, a review of many studies 16 of blood flow during CPR revealed that previous estimates were in many cases too high. The coronary vasculature in particular is completely intrathoracic and, therefore, develops little or no pressure gradient during chest compression. Indeed, the question in recent years is no longer, Why doesn't dosed-chest CPR work better?
Instead, it has become, Why does it work at all? Experienced researchers have commented that "it is surprising that anyone survives closed chest massage with an intact sensa• "17 num. SUa:FSS RATFS-Such skepticism was given support in recent years as pre-hospital care systems were organized and survival rates for out-of-hospital cardiac arrest, particularly in areas with only basic life support capability, were reported. When basic life support was continued for any significant length of time (> 15 minutes) before applying advanced life support (especially defibrillation), success rates were extremely low, often between 0% and 2%. MODUACKOONSOF~QUE
-Many modifications of the basic CPR method were attempted, often under the rubric "new CPR," including interposed abdominal compressions, simultaneous breaths and compressions, and the use of military anti-shock trousers (MAST). 18' 19 After more study, none of these modifications has shown a significant clinical improvement over traditional CPR It is unlikely that they will significantly improve survival rates, and none are currently recommended for use. 20
The role of research Although advanced life support protocols utilizing multiple drugs and varied techniques have been
CARDIAC RESUSCITATION • VOL 87/NO 8/JUNE 1990/POSTGRADUATE MEDICINE
Downloaded by [UQ Library] at 11:01 21 June 2016
There seems to be no question that open-chest cardiac massage provides much greater coronary and cerebral blood flow than closed-chest massage.
employed in resuscitation efforts for many years, rational research into some previously accepted beliefs has begun only in the last decade. Results have often been surprising. One conclusion of this research is that not many interventions increase survival in cardiac arrest. EFFECI1VE ARRFSf INTERVEN-
TIONs-Prompt defibrillation is by far the most important and effective intervention; epinephrine administration is almost certainly effective; and endotracheal intubation is probably effective. Although therapeutic agents, including antiarrhythmics and catecholamines other than epinephrine, occasionally play a role, their overall effect on survival rates is not significant. It is now known that defibrillation is the key to starting stopped hearts and that myocardial perfusion is necessary for defibrillation to be effective. Epinephrine, especially at high doses, causes intense vasoconstriction and helps increase coronary perfusion pressure during CPR. Endotracheal intubation allows proper oxygenation of the poorly perfused myocardium. DELEI'ERIOUS EFFECfS OF
INTERVENTION-As data accumu-
lated on the ineffectiveness or even pernicious outcome of many closed-chest resuscitation interventions, it became clear that success, even with advanced life suppon, would remain limited unless better
ways of perfusing myocardium were found. Furthermore, investigation into resuscitation of cerebral function revealed disturbing evidence that a low-flow circulatory state, such as is often achieved with closed-chest massage, might actually be more deleterious to neuron survival than stasis. 21 The effects of closed-chest massage on intracranial pressure are easily measured and even more easily imagined. Subjecting the hypoxic brain to severe increases in pressure during periods oflowvolume blood flow is a cause of great concern. Recent research on dogs indicates that closed-chest massage, if continued for a significant period, actually may worsen neurologic outcome compared with other resuscitative techniques that provide more blood flow. 22 Even some studies of human cardiac arrest have failed to show a survival advantage with early CPR.23 The results of these investigations led researchers to look for a resuscitation techniq_ue that would allow greater blood-flow volume and lower intercranial pressure. Could open-chest cardiac massage be such a technique? ANIMAL SllJD~Several animal models have been developed to test the effectiveness of resuscitation techniques. In general, the open-chest technique, when performed on a simulated arrest model, results in blood-flow volume of two to three times that of the
VOL 87/NO 8/JUNE 1990IPOSTGRADUATE MEDICINE • CARDIAC RESUSCITATION
closed-chest technique as well as a better rate of survival and higher degree of neurologic recovery. 24•25 A lower rate of complications commonly resulting from the closedchest method (eg, splenic and hepatic lacerations and pulmonary contusions) is incidentally noted. 26•27 HUMAN SllJD~About 30 years ago, Del Guercio and colleagu~8 measured cardiac output and other hemodynamic parameters of hospital patients with cardiac arrest, both while resuscitation was being performed with the closed-chest method and again after the chest was opened. Their study showed greatly increased blood flow (doubled cardiac output) and generally improved hemodynamics when the chest was open. More recently, other cases in which hemodynamic measurements have been made with more sophisticated techniques during both open- and closed-chest massage have unequivocally confirmed these findings. 29 There seems to be no question that the open-chest technique provides much greater coronary and cerebral blood flow than the closed-chest procedure. At least one randomized human study has been performed comparing the two. Geehr and Auerbach30 performed a randomized study of 52 patients who had out-of-hospital cardiac arrest. Thoracotomy and open-chest massage were performed on patients in the study continued 191
The major advantage of emergency thoracotomy and open-chest cardiac massage over external chest compression is the tremendous increase in cardiac output.
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Table 1. Advantages of emergency thoracotomy and open-chest massage in cardiac arrest Increased cardiac output Immediate diagnosis and treatment of: Pericardia! tamponade Occult hypovolemia Tension pneumothorax Direct defibrillation Aortic compression (or crossclamping) Direct mediastinal warming for severe hypothermia Direct aspiration of intracardial air Direct myocardial pacing Verification or refutation of apparent electromechanical dissociation
Table 2. Indications for emergency thoracotomy and open-chest massage in cardiac arrest Failure to establish adequate cardiac output with closed-chest cardiac massage for any reason Atypical anatomy Suspected cardiac tamponade Suspected occult hypovolemia Refractory ventricular fibrillation Hypothermic cardiac arrest Massive air embolism Recent sternotomy
group immediately on arrival in the emergency department, whereas the control group was treated by traditional CPR and advanced cardiac life support protocols. There were three short-term survivors but 192
no long-term survivors from each group. UnfortUnately, the study had a serious flaw: All the patients had received standard pre-hospital care, including rather prolonged advanced cardiac life support services, before being entered into the study. It is perhaps not surprising that open-chest cardiac massage did not show a distinct advantage when performed after about 20 minutes of closed-chest resuscitative efforts.
diately at thoracotomy and relieved in seconds under direct visualization, clearly an advantage over the blind, usually futile attempts at pericardiocentesis through the chest wall during conventional
CPR
Tension pneumothorax, also a commonly unrecognized complication of cardiac arrest, is relieved with opening of the chest. Occult hypovolemia from any cause (eg, unrecognized trauma, ruptured aneurysm, severe dehydration) is Advantages of open-chest recognized immediately on opencardiac massage ing the chest and feeling the fullThe major advantage of emergency ness of the heart chambers. Heart thoracotomy and open-chest masrhythm may also be ascertained insage over external chest compresstantaneously. sion is the tremendous increase in Often, cases that appear to be cardiac output. In fact, the introventricular fibrillation on the basis duction to a recent revieW 1 of the of the electrocardiographic rhythm open-chest technique stated that strip are found on thoracotomy to "few seriously question the hemobe asystole, and occasionally the redynamic superiority of open-chest verse is found. Rare cases of refracCPR over extended chest compres- tory ventricular fibrillation that sion." However, open-chest mascannot be defibrillated through the sage has other specific advantages chest wall can be managed with dias well (table 1). Simply stated, it rect defibrillation of the heart musallows immediate diagnosis and cle, as is done routinely in open treatment of all commonly reheart surgery. versible causes of cardiac arrest. It is Finally, the open-chest techworth noting that official Amerinique may lead to the prompt dican Heart Association guidelines agnosis of cardiorrhexis (rupture of have long accepted the concept of the myocardium) or other untreatinternal cardiac compression when able conditions, allowing prompt closed-chest CPR is ineffective. 12•20 termination of prolonged and fuDIAGNOSTIC ADVANfAGFS-tile resuscitative efforts. Pericardial tamponade often prellffiRAPEUTIC ADVANfAGFS-sents as electromechanical dissocia- With the chest open, the aorta may tion. This can be identified immebe compressed or clamped to redi-
CARDIAC RESUSCITATION • VOL 87/NO 8/JUNE 1990IPOSTGRADUATE MEDICINE
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Appropriate indications for open-chest cardiac massage must be present; patients resuscitated in this manner quite clearly require tube thoracostomy and post-thoracotomy care.
rect blood flow to the heart and brain, as is commonly done in the trauma setting. Theoretically, the open-chest technique could be used to facilitate aspiration of air from the right atrium in cases of air embolism, such as may occur during dialysis or insertion of central venous lines. Severe hypothermia in conjunction with cardiac arrest is already an accepted indication for thoracotomy and open-chest mas-
sage.32
An additional benefit of openchest massage is that many complications of the closed-chest technique would likely be avoided. Several studies'·" have documented the frequent occurrence of rib fractures, pulmonary and myocardial contusions, and visceral (especially hepatic and splenic) lacerations after closed-chest massage. The open-chest technique avoids most of these types of complications. Technique of open-chest cardiac massage The emergency thoracotomy is a straightforward technique, identical to that performed routinely in selected cases of penetrating trauma. However, it is imperative that appropriate indications for the technique be present (table 2). Patients resuscitated in this manner quite clearly require tube thoracostomy and post-thoracotomy care as well as intensive cardiac care for the underlying condition. Bircher and Safar'3 have com-
mented that "any physician can be trained to perform this procedure in a safe and expedient manner" and have suggested ways that this training might be accomplished. Del Guercio, 17 20 years after his own pioneering studies, has recently opined that "any medicine school graduate can (and should) be trained in open chest resuscitation." Certainly the procedure may be rapidly performed by any appropriately trained emergency physician or surgeon with standard instruments in a normally equipped facility. 13 Essentially, an incision is made in the fourth or fifth intercostal space and extended laterally from the sternal border to the midaxillary line. The muscle layer is divided in a blunt fashion, and with the use of rib spreaders, the chest cavity is opened to expose the heart and great vessels. Other than rib spreaders, no special equipment is required. 3435 The aorta may be compressed against the vertebral column using simple pressure; cross-clamping may be difficult. As long as the heart is massaged from apex to base, with adequate time allowed for filling the chambers, any of several simple techniques is acceptable. There is some evidence that opening the pericardium, which immediately relieves pericardia! effusion and tamponade, allows for more efficacious massage with higher cardiac output. It is very fea-
continued VOL 87/NO 8/JUNE 1990/POSTGRADUATE MEDICINE • CARDIAC AESUSCITATlON
193
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sible to palpate the carotid or other central pulse with one hand while performing massage with the other hand.
Summary
Open-chest cardiac massage was widely and successfully used for many decades before its virtual abandonment 25 years ago. Both experimental evidence and basic physiologic evidence indicate
that it has many advantages over dosed-chest massage (especially increased cardiac output). Both resuscitation techniques have specific and unique advantages and disadvantages: They are not mutually exclusive. However, significant increases in rates of survival after cardiac arrest cannot be expected with variations of dosed-chest cardiac massage and standard advanced life support services. Therefore, physicians must be willing to support
controlled human studies that can definitively determine the proper role of each in resuscitation after cardiac arrest. IVt'l
-®
Earn credit on this article. See CME Quiz.
Address for correspondence: Michael B. Heller, MD, Division of Emergency Medicine, Depanment of Medicine, University of Pittsburgh School of Medicine, 230 McKee Place, Suite 500, Pittsburgh, PA 15213.
References 1. Kouwenhm.:n WB, Judd JR, Knickerbocker
GG. Closed-chest cardiac massage. JAMA 1960; 1730ul): 1064-7 2. Hake TG. Srudies on ether and chloroform from Prof. Schiff's physiological laboratory. Practitioner 1874:12:241 3. Sykes MK, Ahmed N. Emergency treatment of cardiac arrest. Lancet 1963;2(Aug 17):347-9 4. Stephenson HE, Reid LC, Hinton ]w. Some common denominators in I ,200 cases of cardiac arrest. Ann Surg 1953:135(5):731-44 5. Powner DJ, Holcombe PA, Mello L\. Cardiopulmonary resuscitation-related injuries. Crit Care Med 1984; 12(1 ):54-5 6. Altermeier WA, Todd]. Srudies on the incidence of infection following open chest massage for cardiac arrest. Ann Surg 1963: 158(0ct):59M>07 7. Stephenson HE. Cardiac arrest and resuscitation. 3d ed. St Louis: CV Mosby, 1969 8. Adelson L A clinicopathologic srudy of the anatomic changes in the hean resulting from cardiac massage. Surg Gynecol Obstet 1957: I 04:513-23 9. Shocket E, Rosenblum R Successful open cardiac massage after 75 minutes of closed massage. JAMA 1967:200(4):333-5 10. GH. CPR lifesaving techniquesGallup pol. Princeton, NJ: Am Instirute of Public Opinion, 1977Jun
Galluf
11. RudikoffMf, Maujthan WI.., FJfron M, et
al. Mechanisms of blood tlow during cardiopulmonary resuscitation., Circulation 1980;61 (2):34552 12. Standards for cardiopulmonary resuscitation (CPR) and emergency cardiac care (ECC). JAMA 1974;227(7 Suppl):837-68 13. Babbs CF. New versus old theories of blood flow during CPR. Crit Care Med 1980;8(3):191-5 14. Lesser R, Bin:her N, Safar P, et al. Venous
194
valving during standard cardiopulmonary resuscitation. Anaesthesiology 1980;53(Suppl): 153 15. Werner JA, Greene HL, Janko CL, et al. Two-dimensional echocardiography during CPR in man: implicatiom regarding the mechanism of blood flow. Crit Care Med 1981 ;9(5):375-6 16. Luoe JM, Cary JM, Ross BK, et al. New developments in cardiopulmonary resuscitation. JAMA 1980:244(12):1366-70 17. Del Guercio l.R. A plea for open chest CPR Am J Emerg Med 1982;2(6):556-{)5 18. ChandraN, RudikoffM, Weisfddt ML Simultaneous chest compression and ventilation at high airway pressure during cardiopulmonary resuscitation. Lancet 1980;1(8161):175-8 19. Bin:her N, Safar P. Comparison of standard and "new" closed-
ISSN: 0032-5481 (Print) 1941-9260 (Online) Journal homepage: http://www.tandfonline.com/loi/ipgm20
Open-chest cardiac massage Michael B. Heller MD To cite this article: Michael B. Heller MD (1990) Open-chest cardiac massage, Postgraduate Medicine, 87:8, 189-194, DOI: 10.1080/00325481.1990.11704682 To link to this article: http://dx.doi.org/10.1080/00325481.1990.11704682
Published online: 17 May 2016.
Submit your article to this journal
View related articles
Citing articles: 1 View citing articles
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=ipgm20 Download by: [UQ Library]
Date: 21 June 2016, At: 11:01
Open-chest cardiac massage The possible rebirth of an old procedure
Michael B. Heller, MD
Downloaded by [UQ Library] at 11:01 21 June 2016
Preview For the last 30 years, the emergency medical response to a patient in cardiac arrest has been cardiopulmonary resuscitation (CPR), incorporating closed-chest cardiac massage. However, open-chest cardiac massage predates CPR as treatment for cardiac arrest and may offer advantages in some cases. Dr Heller examines the two methods and compares their efficacy.
The universal acceptance of dosedchest cardiac massage by both the medical profession and the public sometimes makes it difficult to recall that cardiopulmonary resuscitation (CPR) as we know it was introduced only 30 years ago. Before publication in 1960 of the classic paper by Kouwenhoven and associates 1 describing the dosedchest technique, physicians performing emergency cardiac resuscitations (particularly in hospitals) primarily used open-chest cardiac massage. Although many large studies showed some remarkable results with open-chest cardiac massage, the technique was virtually abandoned, at least fur medical cardiac arrest, as the dosed-chest method became universally accepted. Enthusiasm for the new technique was so great that no comparative studies were done, and physicians have been trained in CPR for decades with no experience or knowledge of the open-chest method. Now, a combination of factors has rekindled interest in the open-
chest technique, which may soon become a preferred method in some types of medical cardiac arrest. History of cardiac resuscitation No one knows what brave soul first performed a thoracotomy to manually restart the heart; it may have been attempted in antiquity. Hakd reponed open-chest resuscitation of chloroform-induced cardiac arrest in 1874, possibly the earliest mention in the medical literature. OPEN-QIFST MASSAGE-This
technique was widely used by the turn of the century, mostly by surgeons in hospitals. Several studi~ were published, some largely skewed toward arrests during surgery. Success rates generally exceeded those recorded for the dosed-chest technique today; but the two patient populations are often not directly comparable. Stephenson and colleagues4 studied a series of 1,200 cardiac arrests in patients who were resuscitated with the open-chest technique (survival rate, 28%). His group included almost 200 pa-
VOL 87/NO 8/JUNE 1990/POSTGRADUATE MEDICINE • CARDIAC RESUSCITATION
tients resuscitated in nonsurgical settings; even this group had a survival rate of about 17%. Although these studies were inelegant by today's standards because they were retrospective and uncontrolled, there was great enthusiasm for the open-chest technique. Major complications appeared to be remarkably infrequent in patients who survived, and compared with CPR, a relative freedom from serious infection was particularly notable.5-9 A radical change occurred from the mid 1960s through the 1970s: The open-chest technique was relegated almost exclusively to emergency trauma situations or arrest during thoracotomy. Although a few adherents persisted and dramatic saves continued to be reported, the open-chest method was widely considered obsolete. QDSED-CHFSf MASSAGE-The
new technique became the officially approved method of resuscitatipn for virtually every group from the American Heart Association to the American Red Cross to the Boy Scouts. Within 15 years, 12 million Americans had been trained in CPR, and a survey indicated that almost half the adult population planned on taking a CPR course. 10 While the appeal of the dosedchest technique is perhaps understandable, the enthusiasm with which it was uncritically embraced continued 189
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The coronary vasculature is completely intrathoracic and, therefore, develops little or no pressure gradient during chest compression.
Furthermore, it was widely published that one third of the normal cardiac output could be rather routinely obtained by properly applying the technique. 12 In recent years, however, these and many other previously held beliefS concerning dosed-chest resuscitation have been shown to be false. Current resuscitation theory An era of skepticism and a general
Michael B. Heller, MD Dr Heller is associate professor, division of emergency medicine, department of medicine, University of Pittsburgh School of Medicine; associate director, Center for Emergency Medicine; and medical director, Specialized Treatment and Transport (STAT), an aeromedical service in Pittsburgh. He has a long-standing interest in resuscitation techniques.
surely must make it one of the great fads in American medical history. It is surprising how little was actually known about the mechanics of the technique, although extremely specific guidelines for administering CPR were and still are promulgated. Texts on both basic and advanced life support did and sometimes still do explain that the beneficial effects of the dosed-chest technique are due to a physical compression of the heart between the sternum and the vertebrae. 11 190
reevaluation of the usefulness of dosed-chest cardiac massage began when several groups in the early 1980s demonstrated that the heart itself has little to do with circulation during chest compression. Since the heart chambers do not fill and valves do not move during CPR, alternative explanations for the production of blood flow have appeared. 13. 15 MEOIANISM OF BLOOD FI.DW-
In general, it is now widely accepted that blood flow during chest compression is largely the result of phasic changes in intrathoracic pressure rather than pressure in the extrathoracic vessels. Furthermore, a review of many studies 16 of blood flow during CPR revealed that previous estimates were in many cases too high. The coronary vasculature in particular is completely intrathoracic and, therefore, develops little or no pressure gradient during chest compression. Indeed, the question in recent years is no longer, Why doesn't dosed-chest CPR work better?
Instead, it has become, Why does it work at all? Experienced researchers have commented that "it is surprising that anyone survives closed chest massage with an intact sensa• "17 num. SUa:FSS RATFS-Such skepticism was given support in recent years as pre-hospital care systems were organized and survival rates for out-of-hospital cardiac arrest, particularly in areas with only basic life support capability, were reported. When basic life support was continued for any significant length of time (> 15 minutes) before applying advanced life support (especially defibrillation), success rates were extremely low, often between 0% and 2%. MODUACKOONSOF~QUE
-Many modifications of the basic CPR method were attempted, often under the rubric "new CPR," including interposed abdominal compressions, simultaneous breaths and compressions, and the use of military anti-shock trousers (MAST). 18' 19 After more study, none of these modifications has shown a significant clinical improvement over traditional CPR It is unlikely that they will significantly improve survival rates, and none are currently recommended for use. 20
The role of research Although advanced life support protocols utilizing multiple drugs and varied techniques have been
CARDIAC RESUSCITATION • VOL 87/NO 8/JUNE 1990/POSTGRADUATE MEDICINE
Downloaded by [UQ Library] at 11:01 21 June 2016
There seems to be no question that open-chest cardiac massage provides much greater coronary and cerebral blood flow than closed-chest massage.
employed in resuscitation efforts for many years, rational research into some previously accepted beliefs has begun only in the last decade. Results have often been surprising. One conclusion of this research is that not many interventions increase survival in cardiac arrest. EFFECI1VE ARRFSf INTERVEN-
TIONs-Prompt defibrillation is by far the most important and effective intervention; epinephrine administration is almost certainly effective; and endotracheal intubation is probably effective. Although therapeutic agents, including antiarrhythmics and catecholamines other than epinephrine, occasionally play a role, their overall effect on survival rates is not significant. It is now known that defibrillation is the key to starting stopped hearts and that myocardial perfusion is necessary for defibrillation to be effective. Epinephrine, especially at high doses, causes intense vasoconstriction and helps increase coronary perfusion pressure during CPR. Endotracheal intubation allows proper oxygenation of the poorly perfused myocardium. DELEI'ERIOUS EFFECfS OF
INTERVENTION-As data accumu-
lated on the ineffectiveness or even pernicious outcome of many closed-chest resuscitation interventions, it became clear that success, even with advanced life suppon, would remain limited unless better
ways of perfusing myocardium were found. Furthermore, investigation into resuscitation of cerebral function revealed disturbing evidence that a low-flow circulatory state, such as is often achieved with closed-chest massage, might actually be more deleterious to neuron survival than stasis. 21 The effects of closed-chest massage on intracranial pressure are easily measured and even more easily imagined. Subjecting the hypoxic brain to severe increases in pressure during periods oflowvolume blood flow is a cause of great concern. Recent research on dogs indicates that closed-chest massage, if continued for a significant period, actually may worsen neurologic outcome compared with other resuscitative techniques that provide more blood flow. 22 Even some studies of human cardiac arrest have failed to show a survival advantage with early CPR.23 The results of these investigations led researchers to look for a resuscitation techniq_ue that would allow greater blood-flow volume and lower intercranial pressure. Could open-chest cardiac massage be such a technique? ANIMAL SllJD~Several animal models have been developed to test the effectiveness of resuscitation techniques. In general, the open-chest technique, when performed on a simulated arrest model, results in blood-flow volume of two to three times that of the
VOL 87/NO 8/JUNE 1990IPOSTGRADUATE MEDICINE • CARDIAC RESUSCITATION
closed-chest technique as well as a better rate of survival and higher degree of neurologic recovery. 24•25 A lower rate of complications commonly resulting from the closedchest method (eg, splenic and hepatic lacerations and pulmonary contusions) is incidentally noted. 26•27 HUMAN SllJD~About 30 years ago, Del Guercio and colleagu~8 measured cardiac output and other hemodynamic parameters of hospital patients with cardiac arrest, both while resuscitation was being performed with the closed-chest method and again after the chest was opened. Their study showed greatly increased blood flow (doubled cardiac output) and generally improved hemodynamics when the chest was open. More recently, other cases in which hemodynamic measurements have been made with more sophisticated techniques during both open- and closed-chest massage have unequivocally confirmed these findings. 29 There seems to be no question that the open-chest technique provides much greater coronary and cerebral blood flow than the closed-chest procedure. At least one randomized human study has been performed comparing the two. Geehr and Auerbach30 performed a randomized study of 52 patients who had out-of-hospital cardiac arrest. Thoracotomy and open-chest massage were performed on patients in the study continued 191
The major advantage of emergency thoracotomy and open-chest cardiac massage over external chest compression is the tremendous increase in cardiac output.
Downloaded by [UQ Library] at 11:01 21 June 2016
Table 1. Advantages of emergency thoracotomy and open-chest massage in cardiac arrest Increased cardiac output Immediate diagnosis and treatment of: Pericardia! tamponade Occult hypovolemia Tension pneumothorax Direct defibrillation Aortic compression (or crossclamping) Direct mediastinal warming for severe hypothermia Direct aspiration of intracardial air Direct myocardial pacing Verification or refutation of apparent electromechanical dissociation
Table 2. Indications for emergency thoracotomy and open-chest massage in cardiac arrest Failure to establish adequate cardiac output with closed-chest cardiac massage for any reason Atypical anatomy Suspected cardiac tamponade Suspected occult hypovolemia Refractory ventricular fibrillation Hypothermic cardiac arrest Massive air embolism Recent sternotomy
group immediately on arrival in the emergency department, whereas the control group was treated by traditional CPR and advanced cardiac life support protocols. There were three short-term survivors but 192
no long-term survivors from each group. UnfortUnately, the study had a serious flaw: All the patients had received standard pre-hospital care, including rather prolonged advanced cardiac life support services, before being entered into the study. It is perhaps not surprising that open-chest cardiac massage did not show a distinct advantage when performed after about 20 minutes of closed-chest resuscitative efforts.
diately at thoracotomy and relieved in seconds under direct visualization, clearly an advantage over the blind, usually futile attempts at pericardiocentesis through the chest wall during conventional
CPR
Tension pneumothorax, also a commonly unrecognized complication of cardiac arrest, is relieved with opening of the chest. Occult hypovolemia from any cause (eg, unrecognized trauma, ruptured aneurysm, severe dehydration) is Advantages of open-chest recognized immediately on opencardiac massage ing the chest and feeling the fullThe major advantage of emergency ness of the heart chambers. Heart thoracotomy and open-chest masrhythm may also be ascertained insage over external chest compresstantaneously. sion is the tremendous increase in Often, cases that appear to be cardiac output. In fact, the introventricular fibrillation on the basis duction to a recent revieW 1 of the of the electrocardiographic rhythm open-chest technique stated that strip are found on thoracotomy to "few seriously question the hemobe asystole, and occasionally the redynamic superiority of open-chest verse is found. Rare cases of refracCPR over extended chest compres- tory ventricular fibrillation that sion." However, open-chest mascannot be defibrillated through the sage has other specific advantages chest wall can be managed with dias well (table 1). Simply stated, it rect defibrillation of the heart musallows immediate diagnosis and cle, as is done routinely in open treatment of all commonly reheart surgery. versible causes of cardiac arrest. It is Finally, the open-chest techworth noting that official Amerinique may lead to the prompt dican Heart Association guidelines agnosis of cardiorrhexis (rupture of have long accepted the concept of the myocardium) or other untreatinternal cardiac compression when able conditions, allowing prompt closed-chest CPR is ineffective. 12•20 termination of prolonged and fuDIAGNOSTIC ADVANfAGFS-tile resuscitative efforts. Pericardial tamponade often prellffiRAPEUTIC ADVANfAGFS-sents as electromechanical dissocia- With the chest open, the aorta may tion. This can be identified immebe compressed or clamped to redi-
CARDIAC RESUSCITATION • VOL 87/NO 8/JUNE 1990IPOSTGRADUATE MEDICINE
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Appropriate indications for open-chest cardiac massage must be present; patients resuscitated in this manner quite clearly require tube thoracostomy and post-thoracotomy care.
rect blood flow to the heart and brain, as is commonly done in the trauma setting. Theoretically, the open-chest technique could be used to facilitate aspiration of air from the right atrium in cases of air embolism, such as may occur during dialysis or insertion of central venous lines. Severe hypothermia in conjunction with cardiac arrest is already an accepted indication for thoracotomy and open-chest mas-
sage.32
An additional benefit of openchest massage is that many complications of the closed-chest technique would likely be avoided. Several studies'·" have documented the frequent occurrence of rib fractures, pulmonary and myocardial contusions, and visceral (especially hepatic and splenic) lacerations after closed-chest massage. The open-chest technique avoids most of these types of complications. Technique of open-chest cardiac massage The emergency thoracotomy is a straightforward technique, identical to that performed routinely in selected cases of penetrating trauma. However, it is imperative that appropriate indications for the technique be present (table 2). Patients resuscitated in this manner quite clearly require tube thoracostomy and post-thoracotomy care as well as intensive cardiac care for the underlying condition. Bircher and Safar'3 have com-
mented that "any physician can be trained to perform this procedure in a safe and expedient manner" and have suggested ways that this training might be accomplished. Del Guercio, 17 20 years after his own pioneering studies, has recently opined that "any medicine school graduate can (and should) be trained in open chest resuscitation." Certainly the procedure may be rapidly performed by any appropriately trained emergency physician or surgeon with standard instruments in a normally equipped facility. 13 Essentially, an incision is made in the fourth or fifth intercostal space and extended laterally from the sternal border to the midaxillary line. The muscle layer is divided in a blunt fashion, and with the use of rib spreaders, the chest cavity is opened to expose the heart and great vessels. Other than rib spreaders, no special equipment is required. 3435 The aorta may be compressed against the vertebral column using simple pressure; cross-clamping may be difficult. As long as the heart is massaged from apex to base, with adequate time allowed for filling the chambers, any of several simple techniques is acceptable. There is some evidence that opening the pericardium, which immediately relieves pericardia! effusion and tamponade, allows for more efficacious massage with higher cardiac output. It is very fea-
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sible to palpate the carotid or other central pulse with one hand while performing massage with the other hand.
Summary
Open-chest cardiac massage was widely and successfully used for many decades before its virtual abandonment 25 years ago. Both experimental evidence and basic physiologic evidence indicate
that it has many advantages over dosed-chest massage (especially increased cardiac output). Both resuscitation techniques have specific and unique advantages and disadvantages: They are not mutually exclusive. However, significant increases in rates of survival after cardiac arrest cannot be expected with variations of dosed-chest cardiac massage and standard advanced life support services. Therefore, physicians must be willing to support
controlled human studies that can definitively determine the proper role of each in resuscitation after cardiac arrest. IVt'l
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Earn credit on this article. See CME Quiz.
Address for correspondence: Michael B. Heller, MD, Division of Emergency Medicine, Depanment of Medicine, University of Pittsburgh School of Medicine, 230 McKee Place, Suite 500, Pittsburgh, PA 15213.
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GG. Closed-chest cardiac massage. JAMA 1960; 1730ul): 1064-7 2. Hake TG. Srudies on ether and chloroform from Prof. Schiff's physiological laboratory. Practitioner 1874:12:241 3. Sykes MK, Ahmed N. Emergency treatment of cardiac arrest. Lancet 1963;2(Aug 17):347-9 4. Stephenson HE, Reid LC, Hinton ]w. Some common denominators in I ,200 cases of cardiac arrest. Ann Surg 1953:135(5):731-44 5. Powner DJ, Holcombe PA, Mello L\. Cardiopulmonary resuscitation-related injuries. Crit Care Med 1984; 12(1 ):54-5 6. Altermeier WA, Todd]. Srudies on the incidence of infection following open chest massage for cardiac arrest. Ann Surg 1963: 158(0ct):59M>07 7. Stephenson HE. Cardiac arrest and resuscitation. 3d ed. St Louis: CV Mosby, 1969 8. Adelson L A clinicopathologic srudy of the anatomic changes in the hean resulting from cardiac massage. Surg Gynecol Obstet 1957: I 04:513-23 9. Shocket E, Rosenblum R Successful open cardiac massage after 75 minutes of closed massage. JAMA 1967:200(4):333-5 10. GH. CPR lifesaving techniquesGallup pol. Princeton, NJ: Am Instirute of Public Opinion, 1977Jun
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valving during standard cardiopulmonary resuscitation. Anaesthesiology 1980;53(Suppl): 153 15. Werner JA, Greene HL, Janko CL, et al. Two-dimensional echocardiography during CPR in man: implicatiom regarding the mechanism of blood flow. Crit Care Med 1981 ;9(5):375-6 16. Luoe JM, Cary JM, Ross BK, et al. New developments in cardiopulmonary resuscitation. JAMA 1980:244(12):1366-70 17. Del Guercio l.R. A plea for open chest CPR Am J Emerg Med 1982;2(6):556-{)5 18. ChandraN, RudikoffM, Weisfddt ML Simultaneous chest compression and ventilation at high airway pressure during cardiopulmonary resuscitation. Lancet 1980;1(8161):175-8 19. Bin:her N, Safar P. Comparison of standard and "new" closed-
