Clinical paperHaemodynamic variables and functional outcome in hypothermic patients following out-of-hospital cardiac arrest☆
Introduction
Outcome of patients experiencing cardiac arrest is dismal and favourable neurological recovery can only be achieved in a minority.1, 2 Although timely institution of effective cardiopulmonary resuscitation is crucial for survival,3 therapeutic interventions implemented after return of spontaneous circulation (e.g. therapeutic hypothermia) can reduce mortality and improve functional neurologic outcome as well.4, 5, 6
The impact of haemodynamic management during and after therapeutic hypothermia on cerebral outcome is not known. Cerebral perfusion may critically depend on systemic blood flow and arterial blood pressure during the post-cardiac arrest period.7 On the other hand, over-aggressive modulation of haemodynamic function with the use of catecholamines may bear relevant risks. Cerebral hyperperfusion due to arterial hypertension or elevated systemic blood flow could facilitate brain swelling and intracranial hypertension. Liberal use of catecholamines is associated with adverse cardiac side effects and may be detrimental to the heart in the early post-resuscitation period.8 In the immediate phase following return of spontaneous circulation arterial hypotension has been associated with increased mortality,9 whereas arterial hypertension has been suggested to have protective effects.7 We found previously no association between functional outcome after resuscitation and haemodynamic variables during the first 24 h of intensive care in patients who were not treated with therapeutic hypothermia.10 Since hypothermia has diverse cardiovascular and metabolic effects,11 data from normothermic post-cardiac arrest patients cannot be extrapolated to those treated with hypothermia.
In this retrospective cohort study, we evaluated whether there is an association between haemodynamic variables collected during the first 24 h after intensive care unit (ICU) admission and neurological outcome in comatose out-of-hospital cardiac arrest (OHCA) victims subjected to therapeutic hypothermia.
Section snippets
Methods
This study was performed in a 36-bed multi-disciplinary ICU in a university hospital. Medical records from April 1, 2007 until December 30, 2010 were reviewed for comatose patients admitted after resuscitation from OHCA treated with mild hypothermia. Cardiac arrest was defined as circulatory collapse without a palpable carotid or femoral pulse resulting in the need for mechanical cardiopulmonary resuscitation with chest compressions and ventilation. Coma was defined as a Glasgow Coma scale < 9, 30
Results
During the study period, 260 patients were admitted to the ICU after cardiac arrest. Hundred and thirty four of them fulfilled the inclusion criteria and were included in this analysis (Electronic supplementary material-Fig. 2). Reasons for exclusion were: in-hospital cardiac arrest (n = 10), no induction of therapeutic hypothermia (n = 116). Sixty-seven (50%) of study patients were classified as having favourable outcome according to the cerebral performance category at day 28 after cardiac
Discussion
In this retrospective analysis of 134 OHCA patients treated with therapeutic hypothermia, adverse neurological outcome at day 28 was associated with higher mean perfusion pressure and cardiac index. While no threshold limit critical for neurological outcome was detected for cardiac index, drops below a mean perfusion pressure of 80 mmHg appeared to be associated with adverse functional outcome. Furthermore, patients with adverse outcome received more often noradrenaline at higher dosages than
Conclusion
Mean perfusion pressure and cardiac index during the first 24 h after ICU admission were weakly associated with neurological outcome in an OHCA population undergoing therapeutic hypothermia. Further studies need to elucidate whether norepinephrine-induced increases in perfusion pressure and cardiac index may contribute to adverse neurologic outcome following OHCA.
Conflict of interest statement
No author has a conflict of interest in regards of drugs or techniques described in this manuscript.
References (24)
- et al.
Cardiopulmonary resuscitation of adults in the hospital: a report of 14,720 cardiac arrests from the National Registry of Cardiopulmonary Resuscitation
Resuscitation
(2003) - et al.
Predicting neurological outcome following cardiac arrest
J Neurol Sci
(2007) - et al.
Epidemiology and outcomes from non-traumatic out-of-hospital cardiac arrest in Korea: a nationwide observational study
Resuscitation
(2010) - et al.
Post-cardiac arrest syndrome: epidemiology, pathophysiology, treatment, and prognostication. A Scientific Statement from the International Liaison Committee on Resuscitation; the American Heart Association Emergency Cardiovascular Care Committee; the Council on Cardiovascular Surgery and Anesthesia; the Council on Cardiopulmonary, Perioperative, and Critical Care; the Council on Clinical Cardiology; the Council on Stroke
Resuscitation
(2008) - et al.
Assessment of neurological prognosis in comatose survivors of cardiac arrest BRCT I study group
Lancet
(1994) - et al.
Detection of artifacts in monitored trends in intensive care
Comput Methods Programs Biomed
(2000) - et al.
Implementation of a standardised treatment protocol for post resuscitation care after out-of-hospital cardiac arrest
Resuscitation
(2007) - et al.
Early arterial hypotension is common in the post-cardiac arrest syndrome and associated with increased in-hospital mortality
Resuscitation
(2008) - et al.
Changes in cerebral blood flow and oxygen extraction during post-resuscitation syndrome
Resuscitation
(2008) Mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest
N Engl J Med
(2002)
Treatment of comatose survivors of out-of-hospital cardiac arrest with induced hypothermia
N Engl J Med
Autoregulation of cerebral blood flow in patients resuscitated from cardiac arrest
Stroke
Cited by (35)
European Resuscitation Council and European Society of Intensive Care Medicine Guidelines 2021: Post-resuscitation care
2021, ResuscitationCitation Excerpt :Based on the evidence summarised by ILCOR9 we suggest avoiding hypotension (MAP < 65 mmHg) and targeting MAP to achieve adequate urine output (>0.5 mL−1 kg h−1) and normal or decreasing lactate values (best practice statement). Tachycardia was associated with poor outcome in one retrospective study.153 During mild induced hypothermia the normal physiological response is bradycardia.
Cardiac output during targeted temperature management and renal function after out-of-hospital cardiac arrest
2019, Journal of Critical CareCitation Excerpt :As soon as possible after admission to the intensive care unit (ICU), hemodynamics were monitored with an arterial pressure catheter inserted transcutaneously in the radial artery, and a balloon-tipped, 7.5F triple lumen PAC (Swan-Ganz, Edwards Lifesciences, Irvine, CA) with CVP values attained from the proximal port. Cardiac output, pulmonary capillary wedge pressure and CVP were measured at six prespecified time points: (T0) upon insertion of the PAC, (T4) at target temperature, (T16) after 16 h, (T28) after 28 h, (T36) after 36h (at 37 °C) and (T48) after 48 h. Perfusion pressure was calculated based on MAP and CVP at each time point (MAP – CVP = perfusion pressure) [19]. Cardiac output was measured with rapid injection of cold isotonic glucose bolus using the thermodilution technique.
Invasive Hemodynamics and Outcomes in Cardiac Arrest Survivors Undergoing Targeted Temperature Management
2019, American Journal of CardiologyCitation Excerpt :Contrary to the postmyocardial infarction and septic shock cohorts, the early characterization of invasive hemodynamics does not seem to predict outcomes in arrest survivors who underwent TTM.9,16 This results contrast with some reports from the pre- and post-TTM era that linked hemodynamic instability, changes in the mean perfusion pressure, and postarrest CI with survival and/or neurologic outomes.7,8,12,17 However, other studies support these findings based on a lack of correlation between initial CVP, myocardial depression (defined as cardiac index (<1.5 L/m/m2), SVO2, or SVR and outcomes after cardiac arrest.13,18,19
Relative tachycardia is associated with poor outcomes in post-cardiac arrest patients regardless of therapeutic hypothermia
2019, American Journal of Emergency Medicine
- ☆
A Spanish translated version of the summary of this article appears as Appendix in the final online version at http://dx.doi.org/10.1016/j.resuscitation.2012.10.012.
- a
Both authors contributed equally to this manuscript.