Resuscitation 85 (2014) 516–521
Contents lists available at ScienceDirect
Resuscitation journal homepage: www.elsevier.com/locate/resuscitation
Clinical Paper
Duplex sonography of cerebral blood flow after cardiac arrest—A prospective observational study夽 Florian Doepp (Connolly) a,∗,1 , Johanna Reitemeier a,1 , Christian Storm b , Dietrich Hasper b , Stephan J. Schreiber a a b
Department of Neurology, University Hospital Charité, Berlin, Germany Department of Internal Medicine, University Hospital Charité, Berlin, Germany
a r t i c l e
i n f o
Article history: Received 27 July 2013 Received in revised form 9 October 2013 Accepted 20 December 2013 Keywords: Cardiac arrest Therapeutic hypothermia Cerebral blood flow Duplexsonography Middle cerebral artery Basal vein of Rosenthal
a b s t r a c t Aim: Despite successful resuscitation, cardiac arrest (CA) often has a poor clinical prognosis. Different diagnostic tools have been established to predict patients’ outcome. However, their sensitivity remains low. Assessment of cerebral perfusion by duplex ultrasound might provide additional information regarding the extent of neuronal damage. The aim of the present study was to analyse the changes of global cerebral blood flow (CBF) and intracranial blood flow parameters in the acute stage after CA and its correlation with patients’ outcome. Methods: We investigated 54 patients (17–85 years, mean age: 63 ± 17 years) after CA with return of spontaneous circulation on an intensive care unit. All patients received therapeutic hypothermia (TH) for 24 h after CA and reanimation. Serial measurements of CBF as well as intracranial blood flow velocities and pulsatility indices of the middle cerebral artery and the basal vein of Rosenthal were performed within the first 10 days using duplex ultrasound. Clinical outcome was measured using the Cerebral Performance Category. Results: Measurements were successful in 53 patients. CBF values differed between 210 and 1100 ml/min. 24 patients (45%) attained a good outcome. No correlation between CBF or intracranial blood flow characteristics and outcome was found. Neither cerebral hypo- nor hyperperfusion was associated with a fatal outcome. Conclusion: Cerebral perfusion varies widely after CA. Neither hypo- nor hyperperfusion seems to be an independent risk factor for poor outcome. Duplex ultrasound of cerebral haemodynamics after CA is suitable but probably of limited prognostic value. © 2014 Elsevier Ireland Ltd. All rights reserved.
1. Introduction Cardiac arrest (CA) caused by ventricular fibrillation (VF) or asystole is one of the leading causes of death and permanent disability in highly developed countries.1 A recent meta-analysis analysing data from more than 140 000 patients found a low survival rate of 23.8% to hospital admission and 7.6% to hospital discharge.2 The clinical outcome is mainly determined by the extent of brain damage caused by global cerebral hypoxia.3 Approximately 60% of patients with successful resuscitation die in hospital, mostly due to neurological injury.4 The prognosis improved substantially
夽 A Spanish translated version of the abstract of this article appears as Appendix in the final online version at http://dx.doi.org/10.1016/j.resuscitation.2013.12.021. ∗ Corresponding author at: Department of Neurology, University Hospital Charité, Augustenburger Platz 1, 13344 Berlin, Germany. E-mail address: fl[email protected] (F. Doepp (Connolly)). 1 These authors contributed equally as first authors. 0300-9572/$ – see front matter © 2014 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.resuscitation.2013.12.021
after introduction of therapeutic hypothermia (TH) with up to 55% of favourable outcome among patients who survive the initial event.5–9 An early and reliable evaluation of the neurological prognosis at the intensive care unit (ICU) is highly relevant for patients, their relatives and the clinicians. Besides the clinical status, several diagnostic tools are established to evaluate the outcome. These are the somatosensory evoked potentials (SEPs), the electroencephalogram (EEG) and the serum level of the neuron specific enolase (NSE).9–12 The disadvantage of all these methods is their relative low sensitivity for fatal outcome.10,12 Furthermore, there is upcoming evidence that decreasing cerebral metabolism by TH will influence and alter these parameters.7,9 Therefore, the evaluation of alternative parameters is requested to improve the accuracy of early prognostic assessment. Direct analysis of the cerebral haemodynamics by means of duplex ultrasound in the acute phase might help to assess the extent of cerebral damage. One proposed approach has been an ultrasound examination of blood flow during resuscitation in the
F. Doepp (Connolly) et al. / Resuscitation 85 (2014) 516–521
carotid arteries.13 However, a possible use would currently be limited to in-hospital resuscitation settings only. Ultrasound data concerning patients after CA are also rare. Intracranial blood flow velocity (BFV) measurements in the middle cerebral artery (MCA) suggested an initial cerebral hypoperfusion within the first day after CA followed by normoperfusion14–16 or a phase of hyperperfusion in several patients associated with the risk of brain swelling and poor outcome.17,18 Preserved cerebrovascular reactivity to changes in PaCO2 15,19 as well as disturbed cerebral autoregulation20 were also described in many patients after CA. However, its significance regarding the outcome remains unclear. Also, venous BFV changes in the basal vein of Rosenthal (BVR) have been reported in hypoxia-associated conditions such as ICP increase and cerebral hypoperfusion.21–24 Extracranial duplex ultrasound is a proven non-invasive bedside tool that allows a reliable assessment of global cerebral blood flow (CBF).25,26 Its value as an outcome parameter after CA is as yet unknown. So far, CBF was evaluated in a pilot study of patients after severe head injury only, demonstrating a clear cut-off value for hypoperfusion indicating fatal outcome.27 The aim of this observational study was to analyse flow patterns of global CBF as well as the intracranial MCA and BVR in the acute phase after CA by serial duplex ultrasound measurements and to correlate them with the patient’s clinical outcome. 2. Methods 2.1. Patients Patients were prospectively enrolled if they fulfilled the following inclusion criteria: Successful resuscitation after CA caused by VF, pulseless electrical activity (PEA) or asystole, sufficient circulation with normal oxygenation whilst they were held in a mild therapeutic hypothermic state. Exclusion criteria were ultrasounddetectable stenosis of haemodynamic relevance in the common carotid artery (CCA), the internal carotid artery (ICA) or vertebral artery (VA), and coma before CA. TH of 33 ◦ C was performed in all patients in the first 24 h after admission, followed by a phase of slow re-warming (0.25 ◦ C/h). Informed consent for all patients was obtained from relatives. The study was approved by the local ethics committee. 2.2. Ultrasound approach All extra- and transcranial duplexsonographic measurements were performed by the same experienced investigator (FD) at three time points: first as soon as possible after CA (
Contents lists available at ScienceDirect
Resuscitation journal homepage: www.elsevier.com/locate/resuscitation
Clinical Paper
Duplex sonography of cerebral blood flow after cardiac arrest—A prospective observational study夽 Florian Doepp (Connolly) a,∗,1 , Johanna Reitemeier a,1 , Christian Storm b , Dietrich Hasper b , Stephan J. Schreiber a a b
Department of Neurology, University Hospital Charité, Berlin, Germany Department of Internal Medicine, University Hospital Charité, Berlin, Germany
a r t i c l e
i n f o
Article history: Received 27 July 2013 Received in revised form 9 October 2013 Accepted 20 December 2013 Keywords: Cardiac arrest Therapeutic hypothermia Cerebral blood flow Duplexsonography Middle cerebral artery Basal vein of Rosenthal
a b s t r a c t Aim: Despite successful resuscitation, cardiac arrest (CA) often has a poor clinical prognosis. Different diagnostic tools have been established to predict patients’ outcome. However, their sensitivity remains low. Assessment of cerebral perfusion by duplex ultrasound might provide additional information regarding the extent of neuronal damage. The aim of the present study was to analyse the changes of global cerebral blood flow (CBF) and intracranial blood flow parameters in the acute stage after CA and its correlation with patients’ outcome. Methods: We investigated 54 patients (17–85 years, mean age: 63 ± 17 years) after CA with return of spontaneous circulation on an intensive care unit. All patients received therapeutic hypothermia (TH) for 24 h after CA and reanimation. Serial measurements of CBF as well as intracranial blood flow velocities and pulsatility indices of the middle cerebral artery and the basal vein of Rosenthal were performed within the first 10 days using duplex ultrasound. Clinical outcome was measured using the Cerebral Performance Category. Results: Measurements were successful in 53 patients. CBF values differed between 210 and 1100 ml/min. 24 patients (45%) attained a good outcome. No correlation between CBF or intracranial blood flow characteristics and outcome was found. Neither cerebral hypo- nor hyperperfusion was associated with a fatal outcome. Conclusion: Cerebral perfusion varies widely after CA. Neither hypo- nor hyperperfusion seems to be an independent risk factor for poor outcome. Duplex ultrasound of cerebral haemodynamics after CA is suitable but probably of limited prognostic value. © 2014 Elsevier Ireland Ltd. All rights reserved.
1. Introduction Cardiac arrest (CA) caused by ventricular fibrillation (VF) or asystole is one of the leading causes of death and permanent disability in highly developed countries.1 A recent meta-analysis analysing data from more than 140 000 patients found a low survival rate of 23.8% to hospital admission and 7.6% to hospital discharge.2 The clinical outcome is mainly determined by the extent of brain damage caused by global cerebral hypoxia.3 Approximately 60% of patients with successful resuscitation die in hospital, mostly due to neurological injury.4 The prognosis improved substantially
夽 A Spanish translated version of the abstract of this article appears as Appendix in the final online version at http://dx.doi.org/10.1016/j.resuscitation.2013.12.021. ∗ Corresponding author at: Department of Neurology, University Hospital Charité, Augustenburger Platz 1, 13344 Berlin, Germany. E-mail address: fl[email protected] (F. Doepp (Connolly)). 1 These authors contributed equally as first authors. 0300-9572/$ – see front matter © 2014 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.resuscitation.2013.12.021
after introduction of therapeutic hypothermia (TH) with up to 55% of favourable outcome among patients who survive the initial event.5–9 An early and reliable evaluation of the neurological prognosis at the intensive care unit (ICU) is highly relevant for patients, their relatives and the clinicians. Besides the clinical status, several diagnostic tools are established to evaluate the outcome. These are the somatosensory evoked potentials (SEPs), the electroencephalogram (EEG) and the serum level of the neuron specific enolase (NSE).9–12 The disadvantage of all these methods is their relative low sensitivity for fatal outcome.10,12 Furthermore, there is upcoming evidence that decreasing cerebral metabolism by TH will influence and alter these parameters.7,9 Therefore, the evaluation of alternative parameters is requested to improve the accuracy of early prognostic assessment. Direct analysis of the cerebral haemodynamics by means of duplex ultrasound in the acute phase might help to assess the extent of cerebral damage. One proposed approach has been an ultrasound examination of blood flow during resuscitation in the
F. Doepp (Connolly) et al. / Resuscitation 85 (2014) 516–521
carotid arteries.13 However, a possible use would currently be limited to in-hospital resuscitation settings only. Ultrasound data concerning patients after CA are also rare. Intracranial blood flow velocity (BFV) measurements in the middle cerebral artery (MCA) suggested an initial cerebral hypoperfusion within the first day after CA followed by normoperfusion14–16 or a phase of hyperperfusion in several patients associated with the risk of brain swelling and poor outcome.17,18 Preserved cerebrovascular reactivity to changes in PaCO2 15,19 as well as disturbed cerebral autoregulation20 were also described in many patients after CA. However, its significance regarding the outcome remains unclear. Also, venous BFV changes in the basal vein of Rosenthal (BVR) have been reported in hypoxia-associated conditions such as ICP increase and cerebral hypoperfusion.21–24 Extracranial duplex ultrasound is a proven non-invasive bedside tool that allows a reliable assessment of global cerebral blood flow (CBF).25,26 Its value as an outcome parameter after CA is as yet unknown. So far, CBF was evaluated in a pilot study of patients after severe head injury only, demonstrating a clear cut-off value for hypoperfusion indicating fatal outcome.27 The aim of this observational study was to analyse flow patterns of global CBF as well as the intracranial MCA and BVR in the acute phase after CA by serial duplex ultrasound measurements and to correlate them with the patient’s clinical outcome. 2. Methods 2.1. Patients Patients were prospectively enrolled if they fulfilled the following inclusion criteria: Successful resuscitation after CA caused by VF, pulseless electrical activity (PEA) or asystole, sufficient circulation with normal oxygenation whilst they were held in a mild therapeutic hypothermic state. Exclusion criteria were ultrasounddetectable stenosis of haemodynamic relevance in the common carotid artery (CCA), the internal carotid artery (ICA) or vertebral artery (VA), and coma before CA. TH of 33 ◦ C was performed in all patients in the first 24 h after admission, followed by a phase of slow re-warming (0.25 ◦ C/h). Informed consent for all patients was obtained from relatives. The study was approved by the local ethics committee. 2.2. Ultrasound approach All extra- and transcranial duplexsonographic measurements were performed by the same experienced investigator (FD) at three time points: first as soon as possible after CA (
