Open Access

Hormonal responses upon return of spontaneous circulation after cardiac arrest: a retrospective cohort study

  • Jin Joo Kim1,
  • Sung Youl Hyun2Email author,
  • Seong Youn Hwang3,
  • Young Bo Jung1,
  • Jong Hwan Shin4,
  • Yong Su Lim1,
  • Jin Seong Cho1,
  • Hyuk Jun Yang1 and
  • Gun Lee1
Critical Care201115:R53

https://doi.org/10.1186/cc10019

Received: 16 August 2010

Accepted: 7 February 2011

Published: 7 February 2011

Abstract

Introduction

Cardiac arrest is often fatal and can be extremely stressful to patients, even if spontaneous rhythm is returned. The purpose of this study was to analyze the hormonal response after return of spontaneous circulation (ROSC).

Methods

This is a retrospective review of the chart and laboratory findings in a single medical facility. The patients admitted to the intensive care unit after successful resuscitation after out-of-hospital cardiac arrest were retrospectively identified and evaluated. Patients with hormonal diseases, patients who received cortisol treatment, those experiencing trauma, and pregnant women were excluded. Serum cortisol, adrenocorticotropic hormone (ACTH), and anti-diuretic hormone (ADH (vasopressin)) were analyzed and a corticotropin-stimulation test was performed. Mortality at one week and one month after admission, and neurologic outcome (cerebral performance category (CPC)) one month after admission were evaluated.

Results

A total of 117 patients, including 84 males (71.8%), were evaluated in this study. One week and one month after admission, 87 (74.4%) and 65 patients (55.6%) survived, respectively. Relative adrenal insufficiency, and higher plasma ACTH and ADH levels were associated with shock-related mortality (P = 0.046, 0.005, and 0.037, respectively), and ACTH and ADH levels were also associated with late mortality (P = 0.002 and 0.004, respectively). Patients with relative adrenal insufficiency, ACTH 5 pg/mL, and ADH 30 pg/mL, had a two-fold increased risk of a poor outcome (shock-related mortality): (odds ratio (OR), 2.601 and 95% confidence interval (CI), 1.015 to 6.664; OR, 2.759 and 95% CI, 1.060 to 7.185; OR, 2.576 and 95% CI, 1.051 to 6.313, respectively). Thirty-five patients (29.9%) had a good CPC (1 to 2), and 82 patients (70.1%) had a bad CPC (3 to 5). Age 50 years and an ADH 30 pg/mL were associated with a bad CPC (OR, 4.564 and 95% CI, 1.794 to 11.612; OR, 6.568 and 95% CI, 1.918 to 22.483, respectively).

Conclusions

The patients with relative adrenal insufficiency and higher blood levels of ACTH and ADH upon ROSC after cardiac arrest had a poor outcome. The effectiveness of administration of cortisol and ADH to patients upon ROSC after cardiac arrest is uncertain and additional studies are needed.

Introduction

The recovery of spontaneous circulation (ROSC) after cardiac arrest results in a whole body ischemia-reperfusion syndrome called 'post-cardiac arrest syndrome' [1, 2]. Post-cardiac arrest syndrome is a unique pathophysiological process that involves multiple organs including post-cardiac arrest brain injury, post-cardiac myocardial dysfunction, systemic ischemia/reperfusion response and persistent precipitating pathophysiology [1]. Post-cardiac arrest syndrome resembles multiorgan failure or septic shock but with a more comprehensive meaning. Immediately after ROSC, the heart rate and blood pressure are very unstable. Most patients need inotropics and vasopressors to manage hypotension due to impaired vasoregulation, myocardial dysfunction, and volume depletion. Also, the possibility of multi-organ failure and infection is increased because of systemic inflammatory immune responses and activation of the coagulation cascade [3, 4]. In this study, several serum hormonal concentrations, including cortisol, adrenocorticotropic hormone (ACTH), and anti-diuretic hormone (ADH (vasopressin)) were analyzed in relation to mortality and neurologic outcome upon ROSC after cardiac arrest.

Materials and methods

Study population

The study institution is a 1,300-bed university hospital with an annual emergency intensive care unit (EICU) census of 1,000. This was a retrospective study of patients with ROSC (>24 hours) after cardiac arrest who were admitted to the EICU over a 34-month period between March 2007 and December 2009. The basal characteristics of the patients and the hormonal concentrations (cortisol, ACTH, and ADH) were obtained from laboratory results in their medical records. The patients with underlying hormonal disease (adrenal insufficiency and diabetes insipidus), patients who had already received cortisol and ADH, patients who died within 24 hours of admission, patients who received trauma and patients who were pregnant were excluded. This study was approved by the institutional review board of our center. Informed consent of blood sampling and study was obtained from the next of kin of the patients following the protocol used in our department.

Clinical evaluation and outcomes

The basal characteristics of patients and outcomes were evaluated. Mortality and neurologic outcomes (Cerebral Performance Category (CPC)) were evaluated. We divided the patients into the following three groups: 1) survivors and non-survivors one week after admission (shock-related mortality); 2) survivors and non-survivors one month after admission (late dead from neurological dysfunction including brain death or cardiovascular problem including myocardial infarction and so on); and 3) good CPC (1, 2) and poor CPC (3 to 5) one month after admission.

Laboratory variables

The serum cortisol, ACTH, and ADH levels were measured on the first morning after admission to the EICU (between 12 and 24 hours after ROSC). Tetracosactrin (250 μg, Synacthene®, NORVATIS, Australia) was administered intravenously and blood samples were obtained immediately before injection, and 30 and 60 minutes after injection. The hormonal concentrations were measured by chemiluminescence immunoassay (CLIA). Relative adrenal insufficiency was defined as an increase in serum cortisol of ≤9 μg/dL.

Statistical analysis

The data were analyzed using SPSS software (version 16.0; SPSS, Inc., Chicago, IL, USA). A t-test and chi-square test were used and single and multiple variable logistic regression model analyses were performed to estimate the odds ratios of dying, along with 95% confidence intervals (CIs). Statistical significance was defined as a P- value < 0.05.

Results

The basal characteristics of the patients are shown in Table 1. A total of 117 patients were evaluated in this study; there were 84 males (71.8%). Forty-nine (41.9%) patients had relative adrenal insufficiency on the first morning after admission to the EICU. One week and one month after admission, 87 (74.4%) and 65 patients (55.6%) survived, respectively. Thirty-five patients (29.9%) had a good CPC.
Table 1

Basal characteristics of the patients (N = 117, median (IQR))

Gender, M, n (%)

84 (71.8)

Age (yr)

52(44 to 64)

BLS time (minutes)

5 (2 to 10)

Arrest time (minutes)

36 (21 to 51)

Epinephrine (mg)

3 (2 to 8)

HTN, yes, n (%)

33 (28.2)

DM, yes, n (%)

13 (11.1)

APACHE II

23 (20 to 27)

SOFA

10 (8 to 11)

Lactate (mmol/L)

8.7 (6.6 to 11.8)

Cortisol, basal (μg/dL)

24.91 (15.00 to 37.36)

Cortisol, 30 minutes (μg/dL)

28.73 (22.71 to 40.19)

Cortisol, 60 minutes (μg/dL)

29.56 (23.49 to 42.76)

RAI, Yes, n (%)

49 (41.9%)

ACTH (pg/mL)

5.40 (1.24 to 23.94)

ADH (pg/mL)

22.11 (12.42 to 35.19)

Survivors, at 1 wk

87 (74.4%)

Survivors, at 1 mo

65 (55.6%)

CPC, good, n (%)

35 (29.9%)

ACTH, adrenocorticotropic hormone; ADH, antidiuretic hormone, vasopressin; APACHE, Acute Physiology and Chronic Health Evaluation; BLS, basic life support; CPC, cerebral performance category (good CPC: 1 to 2, poor CPC: 3 to 5).

DM, diabetes mellitus; HTN, hypertension; SOFA, The Sequential Organ Failure Assessment; RAI, relative adrenal insufficiency.

The hormonal concentrations by mortality and neurologic outcomes are shown in Table 2. The basal cortisol concentration was not significantly related to mortality one week and one month after admission, or CPC score, but the ACTH and ADH concentrations were significantly related to mortality one week and one month after admission, and the CPC score (Table 2).
Table 2

Variables by RAI, mortality, and neurologic outcome (N = 117, median values)

 

RAI

1 wk mortality

1 mo mortality

CPC

 

Yes

No

P-value

Survived

Dead

P- value

Survived

Dead

P- value

Good

Poor

P- value

 

(n = 68)

(n = 49)

 

(n = 87)

(n = 30)

 

(n = 65)

(n = 52)

 

(n = 35)

(n = 82)

 

Gender, M, n (%)

49 (72.1)

35 (71.4)

0.940

62 (71.3)

22 (73.3)

0.828

49 (75.4)

35 (67.3)

0.335

31 (88.6)

53 (64.6)

0.008*

Age (yr)

52

53

0.772

52

54

0.422

49

56

0.174

47

56

0.010*

BLS time (minutes)

6

4

0.076

5

6

0.093

5

6

0.207

4

6

0.200

Arrest time (minutes)

40

27

0.004*

31

50

<0.001*

25

44

<0.001*

25

38

0.010*

Epinephrine (mg)

5

2

<0.001*

3

7

0.001*

3

5

0.004*

3

4

0.338

HTN, yes, n (%)

18 (26.5)

15 30.6)

0.507

22 (25.3)

11 (36.7)

0.194

18 (27.7)

15 (28.8)

0.804

9 (25.7)

24 (29.3)

0.668

DM, yes, n (%)

6 (8.8)

7 (14.3)

0.283

8 (9.2)

5 (16.7)

0.298

5 (7.7)

8 (15.4)

0.152

1 (2.9)

12 (14.6)

0.102

APACHE II

23

22

0.889

22

27

0.001*

22

26

<0.001*

31

26

<0.001*

SOFA

10

9

0.062

9

12

<0.001*

9

11

0.001*

9

10

0.029*

Lactate (mmol/L)

9.40

7.55

0.013*

8.50

9.40

0.244

8.40

9.35

0.190

8.30

8.90

0.393

Cortisol, basal (μg/dL)

27.33

16.70

<0.001*

25.05

24.10

0.762

22.74

25.57

0.204

20.45

25.95

0.030*

Cortisol, 30 minutes (μg/dL)

28.74

28.54

0.543

28.89

27.35

0.380

28.29

29.54

0.584

26.45

29.32

0.273

Cortisol, 60 minutes (μg/dL)

29.12

32.46

0.100

29.67

24.64

0.154

29.20

30.74

0.946

29.02

31.53

0.572

ACTH (μg/dL)

7.85

2.12

0.006*

2.60

11.79

0.005*

2.35

9.41

0.002*

2.31

7.85

0.014*

ADH (pg/mL)

24.97

17.11

0.031*

19.81

28.65

0.037*

18.16

28.27

0.004*

14.42

24.80

0.001*

*P < 0.05

ACTH, adrenocorticotropic hormone; ADH, antidiuretic hormone, vasopressin; APACHE, Acute Physiology and Chronic Health Evaluation; BLS, basic life support; CPC, cerebral performance category (good CPC: 1 to 2, poor CPC: 3 to 5); DM, diabetes mellitus; HTN, hypertension; RAI, relative adrenal insufficiency; SOFA, The Sequential Organ Failure Assessment.

Multiple logistic regression by mortality and CPC are shown in Tables 3, 4 and 5. Relative adrenal insufficiency was significantly related to mortality one week after admission by multiple logistic regression analysis (odds ratio (OR), 2.601 and 95% confidence interval (CI), 1.015 to 6.664), but not significantly related to mortality one month after admission and CPC. ACTH was related to mortality one week after admission, but not to others. ADH was related to mortality one week and one month after admission, and CPC based on multiple logistic regression analysis.
Table 3

Multiple logistic regression for mortality (at one week after admission)

Factors

P- value

Odds ratio

95% CI of odds ratio

Observed power

   

Lower

Upper

 

Age 50 yr

0.221

1.784

0.705

4.510

0.261

RAI (+)

0.046

2.601

1.015

6.664

0.371

ACTH 5 pg/mL

0.038

2.759

1.060

7.185

0.428

ADH 30 pg/mL

0.038

2.576

1.051

6.313

0.343

ACTH, adrenocorticotropic hormone; ADH, antidiuretic hormone; RAI, relative adrenal insufficiency.

Table 4

Multiple logistic regression for mortality (at one month after admission)

Factors

P- value

Odds ratio

95% CI of odds ratio

Observed power

   

Lower

Upper

 

Age 50 yr

0.008

3.217

1.348

7.680

0.770

ACTH 5 pg/mL

0.054

2.265

0.987

5.198

0.499

ADH 30 pg/mL

0.008

3.463

1.389

8.635

0.787

ACTH, adrenocorticotropic hormone; ADH, antidiuretic hormone.

Table 5

Multiple logistic regression for bad CPC (at one month after admission)

Factors

P- value

Odds ratio

95% CI of odds ratio

Observed power

   

Lower

Upper

 

Age 50 yr

0.001

4.564

1.794

11.612

0.914

ACTH 5 pg/mL

0.110

2.125

0.843

5.356

0.346

ADH 30 pg/mL

0.003

6.568

1.918

22.483

0.891

ACTH, adrenocorticotropic hormone; ADH, antidiuretic hormone; CPC, Cerebral performance category.

Discussion

Cardiac arrest is an extremely stressful condition, but few studies have investigated the hormonal response after a cardiac arrest. Post-cardiac arrest syndrome shares many features with severe sepsis or shock, including plasma cytokine elevation with deregulated cytokine production, the presence of endotoxin in plasma, coagulation abnormalities, and adrenal dysfunction [1, 5]. Post-cardiac arrest syndrome is a mixed condition of systemic inflammatory responses, hypovolemia, and myocardial dysfunction. During severe illness, including cardiac arrest, many factors can impair the normal hormonal response affecting the hypothalamic-pituitary-adrenal axis [6].

ADH is essential for cardiovascular homeostasis and release from the hypothalamus [7]. ADH synthesis is primarily mediated by variations in plasma effective osmolality and in blood volume or pressure. Landry et al. [8] reported that patients in septic shock indicated inappropriately low plasma ADH levels and an increased pressor sensitivity to exogenous ADH. Relative ADH deficiency may contribute to vasodilatory shock in sepsis, likely because of impaired baroreflex-mediated hormone secretion [9, 10]. Sharshar et al. [11] determined the serum ADH levels in patients with septic shock; serial plasma ADH levels were obtained at baseline, and 6, 24, 48, and 96 hours after the onset of shock. The study showed that plasma ADH levels are increased in nearly all cases during the initial phase of septic shock, and decreased thereafter. A relative ADH deficiency is more likely to occur 36 hours from the onset of shock [11]. Thus, the time at which ADH is measured in relation to the onset of shock is important. In the current study, the hormonal concentrations were measured on the first morning after ICU admission (12 to 24 hours after ROSC). The optimal timing for obtaining the basal and post-stimulation serum cortisol concentrations was recommended at that time, and this was helpful in estimating a prognosis of post-resuscitation disease [12]. Jochberger et al. [13] reported that serum ADH concentrations in patients after cardiac surgery (n = 96; 19.5 ± 30.4 pg/mL) were significantly higher than patients with sepsis (n = 25; 6.5 ± 4.3 pg/mL), and patients admitted for non-surgical diseases (n = 51; 6.5 ± 4.3 pg/mL; P < 0.001). Leclere et al. [14] reported that the median ADH concentration in children with meningococcal septic shock was 41.6 pg/mL and was higher in non-survivors, but not significantly higher. In the current study, we divided the patients into two groups based on the ADH concentration. An ADH concentration >30 pg/mL was associated with a two- to three-fold increased risk of bad outcomes (early and late deaths or poor CPC) based on multiple logistic regression analysis. The basal cortisol concentration was increased initially and not significantly associated with mortality and CPC, but relative adrenal insufficiency was related to early death (within one week following admission). The patients with an ACTH level >5 pg/mL had a three-fold increased risk of early death. Based on the results of the current study, we suggest that within 24 hours of ROSC after cardiac arrest, the cortisol, ACTH, and ADH levels are immediately secreted from hypothalamic-pituitary-adrenal activation following an extremely stressful condition. An adequate initial endogenous stress response may correlate with recovery or even subsequent survival [13]. Hekimian et al. [15] reported that patients who die of early refractory shock after cardiopulmonary resuscitation may have an inadequate adrenal response to the stress. Relative adrenal insufficiency was related to poor prognosis or increased mortality rate in patients with resuscitation after cardiac arrest [12, 16]. The patients with relatively rapid onset adrenal insufficiency, higher plasma ACTH and ADH levels are related to death, and high concentrations of ADH are also related to bad neurologic outcomes. Because these patients have high concentrations of hormones already, the replacement of hormones, including cortisol and vasopressin, is uncertain. ADH did not reduce the mortality rates as compared with other drugs among patients with septic shock, and ADH did not have a benefit over other drugs in increasing survival to discharge or improving neurologic outcomes in patients after cardiac arrest [17, 18].

Our study had the following limitations. First, this was a retrospective, one-center study. Second, the sample sizes were small. Third, hormonal responses are very complicated. Variable factors could affect the hormonal responses in our study.

Conclusions

The patients with relative adrenal insufficiency and higher blood levels of ACTH and ADH upon ROSC after cardiac arrest had a poor outcome. The effectiveness of administration of cortisol and ADH to patients upon ROSC after cardiac arrest is uncertain; additional studies are needed.

Key messages

  • The axis of the hypothalamic-pituitary-adrenal gland was activated in patients with ROSC after cardiac arrest.

  • The patients with relative adrenal insufficiency, still higher ACTH and ADH had a poor outcome.

Abbreviations

ACTH: 

adrenocorticotropic hormone

ADH: 

antidiuretic hormone, vasopressin

APACHE: 

Acute Physiology and Chronic Health Evaluation

BLS: 

basic life support

CLIA: 

chemiluminescence immunoassay

CPC: 

cerebral performance category (good CPC: 1 to 2, poor CPC: 3 to 5)

DM: 

diabetes mellitus

EICU: 

emergency intensive care unit

HTN: 

hypertension

OR: 

odds ratio

RAI: 

relative adrenal insufficiency

ROSC: 

return of spontaneous circulation

SOFA: 

Sequential Organ Failure Assessment.

Declarations

Authors’ Affiliations

(1)
Department of Emergency Medicine, Gachon University Gil Hospital
(2)
Department of Cardiovascular Surgery, Gachon University Gil Hospital
(3)
Department of Emergency Medicine, Sungkunkwan University School of Medicine, Samsung Changwon Hospital
(4)
Department of Emergency Medicine, Seoul Metropolitan Government Seoul National University Boramae Medical Center

References

  1. Neumar RW, Nolan JP, Adrie C, Aibiki M, Berg RA, Böttiger BW, Callaway C, Clark RS, Geocadin RG, Jauch EC, Kern KB, Laurent I, Longstreth WT Jr, Merchant RM, Morley P, Morrison LJ, Nadkarni V, Peberdy MA, Rivers EP, Rodriguez-Nunez A, Sellke FW, Spaulding C, Sunde K, Vanden Hoek T: Post-cardiac arrest syndrome: Epidemiology, pathophysiology, treatment, and prognostification. A consensus statement from the International Liaison Committee on Resuscitation (American Heart Association, Australian and New Zealand Council on Resuscitation, European Resuscitation Council, Heart and Stroke Foundation of Canada, InterAmerican Heart Foundation, Resuscitation Council of Asia, and the Resuscitation Council of Southern Africa); the American Heart Association Emergency Cardiovascualr Care Committee; the Council on Cardiovascular Surgery and Anesthesia; the Council on cardiopulmonary Perioperative, and Critical Care; the Council on Clinical Cardiology; and the Stroke Council. Circulation 2008, 118: 2452-2483. 10.1161/CIRCULATIONAHA.108.190652PubMedView ArticleGoogle Scholar
  2. Adrie C, Laurent I, Monchi M, Cariou A, Dhainaou JF, Spaulding C: Postresuscitation disease after cardiac arrest: a sepsis-like syndrome? Curr Opin Crit Care 2004, 10: 208-212. 10.1097/01.ccx.0000126090.06275.fePubMedView ArticleGoogle Scholar
  3. Adrie C, Adib-Conquy M, Laurent I, Monchi M, Vinsonneau C, Fitting C, Fraisse F, Dinh-Xuan AT, Carli P, Spaulding C, Dhainaut JF, Cavaillon JM: Successful cardiopulmonary resuscitation after cardiac arrest as a "sepsis-like" syndrome. Circulation 2002, 106: 562-568. 10.1161/01.CIR.0000023891.80661.ADPubMedView ArticleGoogle Scholar
  4. Adrie C, Monchi M, Laurent I, Um S, Yan SB, Thuong M, Cariou A, Charpentier J, Dhainaut JF: Coagulopathy after successful cardiopulmonary resuscitation following cardiac arrest: implication of the protein C anticoagulant pathway. J Am Coll Cardiol 2005, 46: 21-28. 10.1016/j.jacc.2005.03.046PubMedView ArticleGoogle Scholar
  5. Cooper MS, Stewart PM: Corticosteroid insufficiency in acutely ill patients. N Engl J Med 2003, 348: 727-734. 10.1056/NEJMra020529PubMedView ArticleGoogle Scholar
  6. Schultz CH, Rivers EP, Feldkamp CS, Goad EG, Smithline HA, Martin GB, Fath JJ, Wortsman J, Nowak RM: A characterization of hypothalamic-pituitary-adrenal axis function during and after human cardiac arrest. Crit Care Med 1993, 21: 1339-1347. 10.1097/00003246-199309000-00018PubMedView ArticleGoogle Scholar
  7. Holmes CL, Patel BM, Russell JA, Walley KR: Physiology of vasopressin relevant to management of septic shock. Chest 2001, 120: 989-1002. 10.1378/chest.120.3.989PubMedView ArticleGoogle Scholar
  8. Landry DW, Levin HR, Gallant EM, Ashton RC, Seo S, D'Alessandro D, Oz MC, Oliver JA: Vasopressin deficiency contributes to the vasodilation of septic shock. Circulation 1997, 95: 1122-1125.PubMedView ArticleGoogle Scholar
  9. Landry DW, Oliver JA: The pathogenesis of vasodilatory shock. N Engl J Med 2001, 345: 588-595. 10.1056/NEJMra002709PubMedView ArticleGoogle Scholar
  10. Jochberger S, Dörler J, Luckner G, Mayr VD, Wenzel V, Ulmer H, Morgenthaler NG, Hasibeder WR, Dünser MW: The vasopressin and copeptin response to infection, severe sepsis, and septic shock. Crit Care Med 2009, 37: 476-482. 10.1097/CCM.0b013e3181957532PubMedView ArticleGoogle Scholar
  11. Sharshar T, Blanchard A, Paillard M, Raphael JC, Gajdos P, Annane D: Circulating vasopressin levels in septic shock. Crit Care Med 2003, 31: 1752-1758. 10.1097/01.CCM.0000063046.82359.4APubMedView ArticleGoogle Scholar
  12. Kim JJ, Lim YS, Shin JH, Yang HJ, Kim JK, Hyun SY, Rhoo I, Hwang SY, Lee G: Relative adrenal insufficiency after cardiac arrest: impact on postresuscitation disease outcome. Am J Emerg Med 2006, 24: 684-688. 10.1016/j.ajem.2006.02.017PubMedView ArticleGoogle Scholar
  13. Jochberger S, Mayr VD, Luckner G, Wenzel V, Ulmer H, Schmid S, Knotzer H, Pajk W, Hasibeder W, Friesenecker B, Mayr AJ, Dünser MW: Serum vasopressin concentrations in critically ill patients. Crit Care Med 2006, 34: 293-299. 10.1097/01.CCM.0000198528.56397.4FPubMedView ArticleGoogle Scholar
  14. Leclere F, Walter-Nicholet E, Leteurtre S, Noizet O, Sadik A, Cremer R, Fourier C: Admission plasma vasopressin levels in children with meningococcal septic shock. Intensive Care Med 2003, 29: 1339-1344. 10.1007/s00134-003-1868-yView ArticleGoogle Scholar
  15. Hékimian G, Baugnon T, Thuong M, Monchi M, Dabbane H, Jaby D, Rhaoui A, Laurent I, Moret G, Fraisse F, Adrie C: Cortisol levels and relative adrenal insufficiency after successfully resuscitated cardiac arrest. Shock 2004, 22: 116-119.PubMedView ArticleGoogle Scholar
  16. Pene F, Hyvernat H, Mallet V, Cariou A, Carli P, Spaulding C, Dugue MA, Mira JP: Prognostic value of relative adrenal insufficiency after out-of-hospital cardiac arrest. Intensive Care Med 2005, 31: 627-33. 10.1007/s00134-005-2603-7PubMedView ArticleGoogle Scholar
  17. Russel JA, Walley KR, Singer J, Gorden AC, Hebert PC, Cooper DJ, Holmes CL, Mehta S, Granton JT, Storms MM, Cook DJ, Presneill JJ, Ayers D, VASST Investigators: Vasopressin versus norepinephrine infusion in patients with septic shock. N Engl J Med 2008, 358: 877-887. 10.1056/NEJMoa067373View ArticleGoogle Scholar
  18. Wyer PC, Perera P, Jin Z, Zhou Q, Cook DJ, Walter SD, Guyatt GH: Vasopressin or epinephrine for out-of-hospital cardiac arrest. Ann Emerg Med 2006, 48: 86-97. 10.1016/j.annemergmed.2005.11.024PubMedView ArticleGoogle Scholar

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© Kim et al.; licensee BioMed Central Ltd. 2011

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.