G Model
ARTICLE IN PRESS
RESUS 5972 1–2
Resuscitation xxx (2014) xxx–xxx
Contents lists available at ScienceDirect
Resuscitation journal homepage: www.elsevier.com/locate/resuscitation
1
Editorial
2
When to say when
3
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
Historically, prehospital care providers continued resuscitative efforts, once initiated, until emergency department arrival where an emergency physician could make termination decisions. Patients could be pronounced dead in the field only in cases in which obvious signs of death such as dependent lividity, decomposition or rigor mortis were evident, or if a do not resuscitate order was available. This practice was perceived to be wasteful of resources while potentially endangering providers proceeding with lights and sirens in apparently futile cases.1,2 Accordingly during the 1990s investigators began attempting to develop criteria that could reliably predict potential survivability among nontraumatic out of hospital cardiac arrest patients (OHCA). The ideal rule would allow for termination of efforts only among patients whose chance of survival was near zero, while calling for continued efforts in patients with survivable circumstances. These efforts culminated in the American Heart Association 2010 guidelines and the National Association of EMS Physicians (NAEMSP) position paper adopting the Basic Life Support termination of resuscitation rule (BLS TOR rule) for use among EMS systems. Subsequently an additional rule was developed to include systems employing Advanced Life Support techniques (ALS TOR rule). Can providers continue to rely on these criteria in the current era of more sophisticated field and post-resuscitation care? The current paper by Diskin and colleagues3 suggests that the short answer is “yes”. During the decade of the 1990s several retrospective studies were published that showed certain criteria could be used to predict survival in adult, nontraumatic, OHCA patients.4–7 Subsequently, the EMS community started to embark on a movement to create termination of resuscitation (TOR) criteria to be used in patients with OHCA who were unlikely to survive despite transportation to the hospital. NAEMSP issued its first position statement in 2000 supporting out of hospital termination based on the available evidence. It included the following criteria/interventions be given prior to termination: cardiopulmonary resuscitation, definitive airway management, intravenous access, at least 20 min of resuscitative efforts, and persistent asystole or PEA arrest with no return of spontaneous circulation (ROSC).8 The negative predictive value (NPV) of the protocol recommendations were then validated by Cone et al.9 Several investigators then began to develop a more simplified clinical decision rule. In 2002 the BLS TOR rule was created. This showed that if the arrest was not witnessed by EMS personnel, there was no ROSC and there was no AED shock delivered prior to transport,
resuscitative efforts could be terminated with 100% sensitivity and a 100% NPV.10 With the adoption of prehospital termination of resuscitation protocols based on retrospective studies there was a need for the criteria to be prospectively validated. Accordingly, in 2006 the BLS TOR rule was prospectively validated by Morrison et al.11 This led to speculation as to whether the rule would be valid in an advanced life support system (ALS) with the additional ALS interventions in play. A secondary data analysis was performed which validated an ALS TOR rule. This rule stated that if OHCA was not witnessed by EMS personnel or a bystander, bystander CPR was not performed, AED shock was not delivered prior to transport, and there was no ROSC prior to transport, efforts could be terminated.12 Finally, the investigation group performed a retrospective data analysis utilizing the Resuscitation Outcomes Consortium Epistry-Cardiac Arrest trial directly comparing the two clinical decision rules and found both had 100% specificity and positive predictive values(PPV). However, the BLS TOR rule resulted in a lower transport rate and therefore is more efficient.13 Due to these research efforts and the 2010 AHA guidelines for CPR and emergency cardiovascular care, NAEMSP published a new position paper adopting the BLS TOR criteria.14 In addition, the BLS TOR rule was implemented and prospectively revalidated in a large multi-center trial.15 Recently, the validity of the TOR rules has come under scrutiny due to advancements in science and the practice of prehospital and post resuscitation care. Accordingly, in this study, Diskin and colleagues sought to revalidate the ALS TOR criteria in an EMS system employing the most up to date techinques.3 This was a retrospective observational study performed at a single EMS agency where all adult patients with nontraumatic OHCA had ACLS performed as per the AHA 2005 guidelines in addition to load distributing band mechanical CPR, 20 cc/kg of intra-arrest cold saline, and if ROSC was obtained or the patient had CPR still in progress then patients were transported to a CPRC (Comprehensive Post Resuscitation Center). The primary outcome was revalidation of the ALS TOR rule. The authors reported 100% specificity and a 100% PPV of the ALS TOR rule in their study, thus revalidating the ALS TOR rule despite the state of the science innovations employed. Caution must be used in validating retrospective data when all patients were not transported as occurred in this study. This potentially serves to bias the results in favor of the TOR rule.16 The secondary outcome was survival of all transported patients at 7, 14, 30, and 180 days. The authors did report a higher 180 day survival rate at 11% versus
http://dx.doi.org/10.1016/j.resuscitation.2014.04.013 0300-9572/© 2014 Published by Elsevier Ireland Ltd.
Please cite this article in press as: Dragoo http://dx.doi.org/10.1016/j.resuscitation.2014.04.013
D,
Falk
JL.
When
to
say
when.
Resuscitation
(2014),
48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91
G Model RESUS 5972 1–2
Editorial / Resuscitation xxx (2014) xxx–xxx
2 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120
121
122
123
124 125 126 127 128 129
Q3 130 131 132 133 134 135 136 137 138 139
ARTICLE IN PRESS
Morrison’s previous study of 3%. This may have resulted from the aggressive vasopressor protocol used during the current study but not previously. The impact on survival resulting from either the addition of mechanical CPR, therapeutic hypothermia or transportation to a CPRC is unclear from the data. Future trials evaluating these elements individually might help focus resources on the most rewarding interventions. A subset analysis of patients within the current data set who did or did not receive the hypothermia protocol might begin to shed light on these issues. At the end of the day, we are not surprised by the continued validity of the ALS TOR rule in the face of the innovations employed in the EMS systems. Therapeutic hypothermia for inpatients who survive OHCA and obtain ROSC improves survival to discharge with a good neurologic outcome.17 In contradistinction, prehospital therapeutic hypothermia for OHCA has not been shown to decrease mortality or improve survival with a good neurologic outcome,18,19 and therefore should not have influenced the results one way or the other. Nor have mechanical CPR devices been shown to provide benefit over manual CPR in the survival of patients with OHCA.20 The 11% survival rate reported by Diskin et al. is higher than the recently published AHA OHCA survival of 9.5%.21 We speculate that transportation of patients to CPRCs, may be responsible for this. Previous studies have shown an increased survival with good neurologic outcome when patients are treated with protocols and procedures for post resuscitation care.22 Accordingly, the 2010 AHA guidelines encouraged the formation of CPRCs.23 Frequent periodic ongoing re-evaluation of BLS TOR and ALS TOR is required as the science and practice of OHCA continues to rapidly progress. Conflict of interest statement No conflicts of interest to declare. References 1. Auerbach PS, Morris Jr JA, Phillips Jr JB, Redlinger SR, Vaughn WK. An analysis of ambulance accidents in Tennessee. J Am Med Assoc 1987;258:1487–90. 2. Kellermann AL, Hackman BB. Terminating unsuccessful advanced cardiac life support in the field. Am J Emerg Med 1987;5:548–9. 3. Diskin FJ, Camp-Rogers T, Peberdy MA, Ornato JP, Kurz MC. External validation of termination of resuscitation guidelines in the setting of intra-arrest cold saline, mechanical CPR, and comprehensive post resuscitation care. Resuscitation 2014, pii: S0300-9572(14)00118-X. 4. Bonnin MJ, Pepe PE, Kimball KT, Clark Jr PS. Distinct criteria for termination of resuscitation in the out-of-hospital setting. J Am Med Assoc 1993;270:1457–62. 5. Kellermann AL, Hackman BB, Somes G. Predicting the outcome of unsuccessful prehospital advanced cardiac life support. J Am Med Assoc 1993;270:1433–6. 6. Levin PD, Pizov R. End-tidal carbon dioxide and outcome of out-of-hospital cardiac arrest. N Engl J Med 1997;337:1694–5. 7. Stratton SJ, Niemann JT. Outcome from out-of-hospital cardiac arrest caused by nonventricular arrhythmias: contribution of successful resuscitation to overall
Please cite this article in press as: Dragoo http://dx.doi.org/10.1016/j.resuscitation.2014.04.013
D,
survivorship supports the current practice of initiating out-of-hospital ACLS. Ann Emerg Med 1998;32:448–53. Bailey ED, Wydro GC, Cone DC. Termination of resuscitation in the prehospital setting for adult patients suffering nontraumatic cardiac arrest. National Association of EMS Physicians Standards and Clinical Practice Committee. Prehosp Emerg Care 2000;4:190–5. Cone DC, Bailey ED, Spackman AB. The safety of a field termination-ofresuscitation protocol. Prehosp Emerg Care 2005;9:276–81. Verbeek PR, Vermeulen MJ, Ali FH, Messenger DW, Summers J, Morrison LJ. Derivation of a termination-of-resuscitation guideline for emergency medical technicians using automated external defibrillators. Acad Emerg Med 2002;9:671–8. Morrison LJ, Visentin LM, Kiss A, et al. Validation of a rule for termination of resuscitation in out-of-hospital cardiac arrest. N Engl J Med 2006;355:478–87. Morrison LJ, Verbeek PR, Vermeulen MJ, et al. Derivation and evaluation of a termination of resuscitation clinical prediction rule for advanced life support providers. Resuscitation 2007;74:266–75. Morrison LJ, Verbeek PR, Zhan C, Kiss A, Allan KS. Validation of a universal prehospital termination of resuscitation clinical prediction rule for advanced and basic life support providers. Resuscitation 2009;80:324–8. Millin MG, Khandker SR, Malki A. Termination of resuscitation of nontraumatic cardiopulmonary arrest: resource document for the national association of EMS physicians position statement. Prehosp Emerg Care 2011;15:547–54.
140
15. Morrison LJ, Eby D, Veigas PV, et al. Implementation trial of the basic life support termination of resuscitation rule: reducing the transport of futile out-of-hospital cardiac arrests. Resuscitation 2014;85:486–91. 16. Morrison LJ, Bigham BL, Alex K, Verbeek R. Termination of resuscitation: a guide to interpreting the literature. Resuscitation 2008;79:387–90. 17. Bernard SA, Gray TW, Buist MD, et al. Treatment of comatose survivors of out-of-hospital cardiac arrest with induced hypothermia. N Engl J Med 2002;346:557–63. 18. Garrett JS, Studnek JR, Blackwell T, et al. The association between intra-arrest therapeutic hypothermia and return of spontaneous circulation among individuals experiencing out of hospital cardiac arrest. Resuscitation 2011;82:21–5. 19. Kim F, Nichol G, Maynard C, et al. Effect of prehospital induction of mild hypothermia on survival and neurological status among adults with cardiac arrest: a randomized clinical trial. J Am Med Assoc 2014;311:45–52. 20. Brooks SC, Hassan N, Bigham BL, Morrison LJ. Mechanical versus manual chest compressions for cardiac arrest. Cochrane Database Syst Rev 2014;2:CD007260. 21. Go AS, Mozaffarian D, Roger VL, et al. Heart disease and stroke statistics – 2014 update: a report from the American Heart Association. Circulation 2014;129:e28–92. 22. Sunde K, Pytte M, Jacobsen D, et al. Implementation of a standardised treatment protocol for post resuscitation care after out-of-hospital cardiac arrest. Resuscitation 2007;73:29–39. 23. Donnino MW, Rittenberger JC, Gaieski D, et al. The development and implementation of cardiac arrest centers. Resuscitation 2011;82:974–8.
163
8.
9. 10.
11. 12.
13.
14.
Danielle Dragoo Q1 Orlando Regional Medical Center, Orlando, FL, USA Q2 Jay L. Falk ∗ Orlando Health, FL, USA ∗ Corresponding author. E-mail addresses: [email protected], [email protected] (J.L. Falk).
15 April 2014
Falk
JL.
When
to
say
when.
Resuscitation
(2014),
141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162
164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186
187 188 189 190
191 192 193
194
ARTICLE IN PRESS
RESUS 5972 1–2
Resuscitation xxx (2014) xxx–xxx
Contents lists available at ScienceDirect
Resuscitation journal homepage: www.elsevier.com/locate/resuscitation
1
Editorial
2
When to say when
3
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
Historically, prehospital care providers continued resuscitative efforts, once initiated, until emergency department arrival where an emergency physician could make termination decisions. Patients could be pronounced dead in the field only in cases in which obvious signs of death such as dependent lividity, decomposition or rigor mortis were evident, or if a do not resuscitate order was available. This practice was perceived to be wasteful of resources while potentially endangering providers proceeding with lights and sirens in apparently futile cases.1,2 Accordingly during the 1990s investigators began attempting to develop criteria that could reliably predict potential survivability among nontraumatic out of hospital cardiac arrest patients (OHCA). The ideal rule would allow for termination of efforts only among patients whose chance of survival was near zero, while calling for continued efforts in patients with survivable circumstances. These efforts culminated in the American Heart Association 2010 guidelines and the National Association of EMS Physicians (NAEMSP) position paper adopting the Basic Life Support termination of resuscitation rule (BLS TOR rule) for use among EMS systems. Subsequently an additional rule was developed to include systems employing Advanced Life Support techniques (ALS TOR rule). Can providers continue to rely on these criteria in the current era of more sophisticated field and post-resuscitation care? The current paper by Diskin and colleagues3 suggests that the short answer is “yes”. During the decade of the 1990s several retrospective studies were published that showed certain criteria could be used to predict survival in adult, nontraumatic, OHCA patients.4–7 Subsequently, the EMS community started to embark on a movement to create termination of resuscitation (TOR) criteria to be used in patients with OHCA who were unlikely to survive despite transportation to the hospital. NAEMSP issued its first position statement in 2000 supporting out of hospital termination based on the available evidence. It included the following criteria/interventions be given prior to termination: cardiopulmonary resuscitation, definitive airway management, intravenous access, at least 20 min of resuscitative efforts, and persistent asystole or PEA arrest with no return of spontaneous circulation (ROSC).8 The negative predictive value (NPV) of the protocol recommendations were then validated by Cone et al.9 Several investigators then began to develop a more simplified clinical decision rule. In 2002 the BLS TOR rule was created. This showed that if the arrest was not witnessed by EMS personnel, there was no ROSC and there was no AED shock delivered prior to transport,
resuscitative efforts could be terminated with 100% sensitivity and a 100% NPV.10 With the adoption of prehospital termination of resuscitation protocols based on retrospective studies there was a need for the criteria to be prospectively validated. Accordingly, in 2006 the BLS TOR rule was prospectively validated by Morrison et al.11 This led to speculation as to whether the rule would be valid in an advanced life support system (ALS) with the additional ALS interventions in play. A secondary data analysis was performed which validated an ALS TOR rule. This rule stated that if OHCA was not witnessed by EMS personnel or a bystander, bystander CPR was not performed, AED shock was not delivered prior to transport, and there was no ROSC prior to transport, efforts could be terminated.12 Finally, the investigation group performed a retrospective data analysis utilizing the Resuscitation Outcomes Consortium Epistry-Cardiac Arrest trial directly comparing the two clinical decision rules and found both had 100% specificity and positive predictive values(PPV). However, the BLS TOR rule resulted in a lower transport rate and therefore is more efficient.13 Due to these research efforts and the 2010 AHA guidelines for CPR and emergency cardiovascular care, NAEMSP published a new position paper adopting the BLS TOR criteria.14 In addition, the BLS TOR rule was implemented and prospectively revalidated in a large multi-center trial.15 Recently, the validity of the TOR rules has come under scrutiny due to advancements in science and the practice of prehospital and post resuscitation care. Accordingly, in this study, Diskin and colleagues sought to revalidate the ALS TOR criteria in an EMS system employing the most up to date techinques.3 This was a retrospective observational study performed at a single EMS agency where all adult patients with nontraumatic OHCA had ACLS performed as per the AHA 2005 guidelines in addition to load distributing band mechanical CPR, 20 cc/kg of intra-arrest cold saline, and if ROSC was obtained or the patient had CPR still in progress then patients were transported to a CPRC (Comprehensive Post Resuscitation Center). The primary outcome was revalidation of the ALS TOR rule. The authors reported 100% specificity and a 100% PPV of the ALS TOR rule in their study, thus revalidating the ALS TOR rule despite the state of the science innovations employed. Caution must be used in validating retrospective data when all patients were not transported as occurred in this study. This potentially serves to bias the results in favor of the TOR rule.16 The secondary outcome was survival of all transported patients at 7, 14, 30, and 180 days. The authors did report a higher 180 day survival rate at 11% versus
http://dx.doi.org/10.1016/j.resuscitation.2014.04.013 0300-9572/© 2014 Published by Elsevier Ireland Ltd.
Please cite this article in press as: Dragoo http://dx.doi.org/10.1016/j.resuscitation.2014.04.013
D,
Falk
JL.
When
to
say
when.
Resuscitation
(2014),
48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91
G Model RESUS 5972 1–2
Editorial / Resuscitation xxx (2014) xxx–xxx
2 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120
121
122
123
124 125 126 127 128 129
Q3 130 131 132 133 134 135 136 137 138 139
ARTICLE IN PRESS
Morrison’s previous study of 3%. This may have resulted from the aggressive vasopressor protocol used during the current study but not previously. The impact on survival resulting from either the addition of mechanical CPR, therapeutic hypothermia or transportation to a CPRC is unclear from the data. Future trials evaluating these elements individually might help focus resources on the most rewarding interventions. A subset analysis of patients within the current data set who did or did not receive the hypothermia protocol might begin to shed light on these issues. At the end of the day, we are not surprised by the continued validity of the ALS TOR rule in the face of the innovations employed in the EMS systems. Therapeutic hypothermia for inpatients who survive OHCA and obtain ROSC improves survival to discharge with a good neurologic outcome.17 In contradistinction, prehospital therapeutic hypothermia for OHCA has not been shown to decrease mortality or improve survival with a good neurologic outcome,18,19 and therefore should not have influenced the results one way or the other. Nor have mechanical CPR devices been shown to provide benefit over manual CPR in the survival of patients with OHCA.20 The 11% survival rate reported by Diskin et al. is higher than the recently published AHA OHCA survival of 9.5%.21 We speculate that transportation of patients to CPRCs, may be responsible for this. Previous studies have shown an increased survival with good neurologic outcome when patients are treated with protocols and procedures for post resuscitation care.22 Accordingly, the 2010 AHA guidelines encouraged the formation of CPRCs.23 Frequent periodic ongoing re-evaluation of BLS TOR and ALS TOR is required as the science and practice of OHCA continues to rapidly progress. Conflict of interest statement No conflicts of interest to declare. References 1. Auerbach PS, Morris Jr JA, Phillips Jr JB, Redlinger SR, Vaughn WK. An analysis of ambulance accidents in Tennessee. J Am Med Assoc 1987;258:1487–90. 2. Kellermann AL, Hackman BB. Terminating unsuccessful advanced cardiac life support in the field. Am J Emerg Med 1987;5:548–9. 3. Diskin FJ, Camp-Rogers T, Peberdy MA, Ornato JP, Kurz MC. External validation of termination of resuscitation guidelines in the setting of intra-arrest cold saline, mechanical CPR, and comprehensive post resuscitation care. Resuscitation 2014, pii: S0300-9572(14)00118-X. 4. Bonnin MJ, Pepe PE, Kimball KT, Clark Jr PS. Distinct criteria for termination of resuscitation in the out-of-hospital setting. J Am Med Assoc 1993;270:1457–62. 5. Kellermann AL, Hackman BB, Somes G. Predicting the outcome of unsuccessful prehospital advanced cardiac life support. J Am Med Assoc 1993;270:1433–6. 6. Levin PD, Pizov R. End-tidal carbon dioxide and outcome of out-of-hospital cardiac arrest. N Engl J Med 1997;337:1694–5. 7. Stratton SJ, Niemann JT. Outcome from out-of-hospital cardiac arrest caused by nonventricular arrhythmias: contribution of successful resuscitation to overall
Please cite this article in press as: Dragoo http://dx.doi.org/10.1016/j.resuscitation.2014.04.013
D,
survivorship supports the current practice of initiating out-of-hospital ACLS. Ann Emerg Med 1998;32:448–53. Bailey ED, Wydro GC, Cone DC. Termination of resuscitation in the prehospital setting for adult patients suffering nontraumatic cardiac arrest. National Association of EMS Physicians Standards and Clinical Practice Committee. Prehosp Emerg Care 2000;4:190–5. Cone DC, Bailey ED, Spackman AB. The safety of a field termination-ofresuscitation protocol. Prehosp Emerg Care 2005;9:276–81. Verbeek PR, Vermeulen MJ, Ali FH, Messenger DW, Summers J, Morrison LJ. Derivation of a termination-of-resuscitation guideline for emergency medical technicians using automated external defibrillators. Acad Emerg Med 2002;9:671–8. Morrison LJ, Visentin LM, Kiss A, et al. Validation of a rule for termination of resuscitation in out-of-hospital cardiac arrest. N Engl J Med 2006;355:478–87. Morrison LJ, Verbeek PR, Vermeulen MJ, et al. Derivation and evaluation of a termination of resuscitation clinical prediction rule for advanced life support providers. Resuscitation 2007;74:266–75. Morrison LJ, Verbeek PR, Zhan C, Kiss A, Allan KS. Validation of a universal prehospital termination of resuscitation clinical prediction rule for advanced and basic life support providers. Resuscitation 2009;80:324–8. Millin MG, Khandker SR, Malki A. Termination of resuscitation of nontraumatic cardiopulmonary arrest: resource document for the national association of EMS physicians position statement. Prehosp Emerg Care 2011;15:547–54.
140
15. Morrison LJ, Eby D, Veigas PV, et al. Implementation trial of the basic life support termination of resuscitation rule: reducing the transport of futile out-of-hospital cardiac arrests. Resuscitation 2014;85:486–91. 16. Morrison LJ, Bigham BL, Alex K, Verbeek R. Termination of resuscitation: a guide to interpreting the literature. Resuscitation 2008;79:387–90. 17. Bernard SA, Gray TW, Buist MD, et al. Treatment of comatose survivors of out-of-hospital cardiac arrest with induced hypothermia. N Engl J Med 2002;346:557–63. 18. Garrett JS, Studnek JR, Blackwell T, et al. The association between intra-arrest therapeutic hypothermia and return of spontaneous circulation among individuals experiencing out of hospital cardiac arrest. Resuscitation 2011;82:21–5. 19. Kim F, Nichol G, Maynard C, et al. Effect of prehospital induction of mild hypothermia on survival and neurological status among adults with cardiac arrest: a randomized clinical trial. J Am Med Assoc 2014;311:45–52. 20. Brooks SC, Hassan N, Bigham BL, Morrison LJ. Mechanical versus manual chest compressions for cardiac arrest. Cochrane Database Syst Rev 2014;2:CD007260. 21. Go AS, Mozaffarian D, Roger VL, et al. Heart disease and stroke statistics – 2014 update: a report from the American Heart Association. Circulation 2014;129:e28–92. 22. Sunde K, Pytte M, Jacobsen D, et al. Implementation of a standardised treatment protocol for post resuscitation care after out-of-hospital cardiac arrest. Resuscitation 2007;73:29–39. 23. Donnino MW, Rittenberger JC, Gaieski D, et al. The development and implementation of cardiac arrest centers. Resuscitation 2011;82:974–8.
163
8.
9. 10.
11. 12.
13.
14.
Danielle Dragoo Q1 Orlando Regional Medical Center, Orlando, FL, USA Q2 Jay L. Falk ∗ Orlando Health, FL, USA ∗ Corresponding author. E-mail addresses: [email protected], [email protected] (J.L. Falk).
15 April 2014
Falk
JL.
When
to
say
when.
Resuscitation
(2014),
141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162
164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186
187 188 189 190
191 192 193
194
