Resuscitation 85 (2014) A3–A4
Contents lists available at ScienceDirect
Resuscitation journal homepage: www.elsevier.com/locate/resuscitation
Editorial
Cognitive impairments after cardiac arrest: Implications for clinical daily practice
Out-of-hospital cardiac arrest (OHCA) survival can be complicated by hypoxic brain injury. A systematic review in 2009 showed that 42–50% of OHCA survivors suffer from long-term cognitive problems. The most affected cognitive domains are memory, attention and executive functioning.1–4 It is important to take potential cognitive impairments into account because even mild cognitive impairments can have a high impact on a person’s functioning in daily life.5,6 In the previous issue of Resuscitation, Ørbo et al. described a prospective study on the important issue of determinants of cognitive outcome in survivors of OHCA.7 They reported that three months after the cardiac arrest cognitive impairments were present in 44% of the 45 studied adult survivors. Besides, they studied associations between cognitive outcome and its determinants. They found that both induced hypothermia and shorter coma duration were associated with a more favorable cognitive outcome. No association was found between the time to return of spontaneous circulation (ROSC) and cognitive impairments. A limitation of this study is the rather small sample size (n = 45) and the potential risk of selection bias. The flow chart of this study shows that, of the 129 OHCA patients leaving the hospital alive, 8 patients were already excluded because of severe anoxic brain injury and 18 because of psychiatric/neurologic disease/learning disabilities. Of the 79 patients that the authors considered eligible for this study, only 57% were included. 19 patients were lost to follow-up of which six were transferred to further treatment and rehabilitation. In addition, 15 patients refused to participate. The patients included seemed to have less emotional complaints than generally reported. To compare, a review by Wilder Schaaf showed signs of depression in 14–45% (in this study 0%) and signs of anxiety in 13% to 61% (in this study 11%).8 Taking all this into account, we suspect that the current sample does not fully represent the population of OHCA survivors as a whole. There appears to be a selective drop out of patients with poorer prognosis. Therefore, we suspect that the overall percentage of patients with cognitive deficits after OHCA might well be higher than the reported 44%. It is important that patients, relatives and health care providers are aware of potential cognitive problems due to a cardiac arrest, because it can have high impact on a person’s functioning in daily life.5,6 Furthermore, patients and health workers should be aware of the treatment options in case of cognitive problems. For patients with other forms of acquired brain injury, cognitive rehabilitation has been proven to be effective.9 During cognitive rehabilitation http://dx.doi.org/10.1016/j.resuscitation.2014.09.022 0300-9572/© 2014 Elsevier Ireland Ltd. All rights reserved.
people learn in an interdisciplinary setting how to compensate for their cognitive impairments and how to use resources in order to retain optimal participation in society. Cognitive rehabilitation also comprises psycho-education to help patients with brain injury and their families how to cope with the cognitive and emotional consequences.10 There are no studies yet on the effectiveness of cognitive rehabilitation for patients with hypoxic brain injury due to cardiac arrest. We expect that OHCA survivors with cognitive deficits can benefit from cognitive rehabilitation interventions in the same way patients with other types of acquired brain injury do. Recently, an intervention that provided information on possible cognitive and emotional consequences three months after cardiac arrest was considered useful by both patients and health workers.11 However, more research on the effectiveness of cognitive rehabilitation after OHCA is needed. The extensive neuropsychological tests used in this study were able to detect even mild cognitive problems. These assessments took approximately 3 h, which makes them not suitable as a screening instrument for clinical daily practice. One could argue to use the Cerebral Performance Category (CPC), part of the Utstein template, as a screening. The CPC is a classification system that roughly estimates the functioning of the patient at time of hospital discharge. Torgersen et al. showed that the CPC is not capable of detecting mild cognitive problems and is therefore not suitable as a screening instrument for cognitive functioning.12,13 Which short cognitive screening instrument would be best for this specific patient group is not known yet. Future research should therefore investigate which concise screening instrument is the best with regard to validity, reliability, sensitivity and specificity. A well-known predictor of cognitive functioning after traumatic brain injury is coma duration.14 However, for survivors of OHCA, evidence on the relation between coma duration and outcome is scarce.15 The question whether induction of hypothermia protects against cognitive disabilities is not yet definitely solved.13,16,17 In this study the hypothermia was, in accordance with guidelines, administered to all patients comatose at time of ROSC.18 During the period of induced hypothermia the natural course of coma cannot be monitored, since the patients are being sedated during this procedure. The design of this study did not allow for randomization with regard to induced hypothermia and probably more patients with a relatively better prognosis were included. Therefore, in our opinion no final conclusions can be drawn yet on the causality between the studied prognostic factors and cognitive outcome.
A4
Editorial / Resuscitation 85 (2014) A3–A4
So, is it possible to draw conclusions for clinical daily practice? First of all, it is essential to be aware of the high incidence (up to 50%) of cognitive impairments in OHCA survivors. This aspect deserves attention in all survivors, but probably even more for patients with longer coma duration. We agree with Ørbo et al. that the threshold for referring OHCA survivors for neuropsychological assessment should be low. However, extensive cognitive testing is time consuming and sometimes stressful for patients. Therefore, there is an urgent need for a suitable and concise cognitive screening instrument. As long as there is no consensus on this, we advise to use locally available screening instruments which measure at least aspects of memory, attention and executive functioning. One could consider using the Montreal Cognitive Assessment (MOCA) as this cognitive screening showed already reasonable sensitivity/specificity in heart failure patients (.64/.66).19 Secondly, health care providers must be aware that there are (cognitive) rehabilitation programs available that can be of benefit for patients with cognitive impairments after a cardiac arrest. Local care chain arrangements can aid in streamlining referral from cardiac care to cognitive rehabilitation services. Conflict of interest statement The authors have no conflicts of interest. References 1. Van Alem AP, De Vos R, Schmand B, Koster RW. Cognitive impairment in survivors of out-of-hospital cardiac arrest. AHJ 2004;148:416–21. 2. Roine RO, Kajaste S, Kaste M. Neuropsychological sequelae of cardiac arrest. JAMA 1993;269:237–42. 3. Sauve MJ, Walker JA, Paul SM, Scheinman MM. Factors associated with cognitive recovery after cardiopulmonary resuscitation. Am J Crit Care 1996;5:27–39. 4. Moulaert VR, Verbunt JA, van Heugten CM, Wade DT. Cognitive impairments in survivors of out-of-hospital cardiac arrest: a systematic review. Resuscitation 2009;80:297–305. 5. Wachelder EM, Moulaert VR, van Heugten C, et al. Life after survival: longterm daily functioning and quality of life after an out-of-hospital cardiac arrest. Resuscitation 2009;80:517–22. 6. Mateen F, Josephs K, Trenerry M, et al. Long-term cognitive outcomes following out-of-hospital cardiac arrest: a population-based study. Neurology 2011;77:1438–45. 7. Ørbo M, Aslaksen PM, Larsby K, et al. Determinants of cognitive outcome in survivors of out-of-hospital cardiac arrest. Resuscitation 2014;85:1462–8. 8. Wilder Schaaf KP, Artman LK, Peberdy MA, et al. Anxiety, depression, and PTSD following cardiac arrest: a systematic review of the literature. Resuscitation 2013;84:873–7. 9. Van Heugten C, Gregório GW, Wade D. Evidence-based cognitive rehabilitation after acquired brain injury: a systematic review of content of treatment. Neuropsychol Rehabil 2012;22:653–73.
10. Daviet JC, Bonan I, Caire JM, et al. Therapeutic patient education for stroke survivors: non-pharmacological management. A literature review. Ann Phys Rehabil Med 2012;55:641–56. 11. Moulaert VR, van Haastregt JC, Wade DT, et al. ‘Stand still . . ., and move on’, an early neurologically-focused follow-up for cardiac arrest survivors and their caregivers: a process evaluation. BMC Health Serv Res 2014;14:34. 12. Langhelle A, Nolan J, Herlitz J, et al. Recommended guidelines for reviewing, reporting, and conducting research on post-resuscitation care: the Utstein style. Resuscitation 2005;66:271–83. 13. Torgersen J, Strand K, Bjelland TW, et al. Cognitive dysfunction and healthrelated quality of life after a cardiac arrest and therapeutic hypothermia. Acta Anaesthesiol Scand 2010;54:721–8. 14. Singh B, Murad MH, Prokop LJ, et al. Meta-analysis of Glasgow coma scale and simplified motor score in predicting traumatic brain injury outcomes. Brain Inj 2013;27:293–300. 15. Lim C, Verfaellie M, Schnyer D, Lafleche G, Alexander MP. Recovery, long-term cognitive outcome and quality of life following out-of-hospital cardiac arrest. J Rehabil Med 2014;46:691–7. 16. Nielsen N, Wetterslev J, Cronberg T, et al. Targeted temperature management at 33 ◦ C versus 36 ◦ C after cardiac arrest. N Engl J Med 2013;369: 2197–206. 17. Cronberg T, Lilja G, Rundgren M, Friberg H, Widner H. Long-term neurological outcome after cardiac arrest and therapeutic hypothermia. Resuscitation 2009;80:1119–23. 18. Peberdy MA, Callaway CW, Neumar RW, et al. American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science. Part 9: Post-cardiac arrest care. Circulation 2010;122: S768–86. 19. Hawkins MA, Gathright EC, Gunstad J, et al. The MoCA and MMSE as screeners for cognitive impairment in a heart failure population: a study with comprehensive neuropsychological testing. Heart Lung 2014;43:462–8.
Paulien H. Goossens a,b Rijnlands Rehabilitation Centre, Leiden, The Netherlands b Leiden University Medical Centre, Department of Orthopaedics, Physical Therapy and Rehabilitation, Leiden, The Netherlands a
Véronique R.M. Moulaert a,b,∗ Adelante, Centre of Expertise in Rehabilitation and Audiology, Hoensbroek, The Netherlands b CAPHRI School for Public Health and Primary Care, Department of Rehabilitation Medicine, Maastricht University, Maastricht, The Netherlands a
∗ Corresponding author. E-mail address: [email protected] (V.R.M. Moulaert)
28 September 2014
Contents lists available at ScienceDirect
Resuscitation journal homepage: www.elsevier.com/locate/resuscitation
Editorial
Cognitive impairments after cardiac arrest: Implications for clinical daily practice
Out-of-hospital cardiac arrest (OHCA) survival can be complicated by hypoxic brain injury. A systematic review in 2009 showed that 42–50% of OHCA survivors suffer from long-term cognitive problems. The most affected cognitive domains are memory, attention and executive functioning.1–4 It is important to take potential cognitive impairments into account because even mild cognitive impairments can have a high impact on a person’s functioning in daily life.5,6 In the previous issue of Resuscitation, Ørbo et al. described a prospective study on the important issue of determinants of cognitive outcome in survivors of OHCA.7 They reported that three months after the cardiac arrest cognitive impairments were present in 44% of the 45 studied adult survivors. Besides, they studied associations between cognitive outcome and its determinants. They found that both induced hypothermia and shorter coma duration were associated with a more favorable cognitive outcome. No association was found between the time to return of spontaneous circulation (ROSC) and cognitive impairments. A limitation of this study is the rather small sample size (n = 45) and the potential risk of selection bias. The flow chart of this study shows that, of the 129 OHCA patients leaving the hospital alive, 8 patients were already excluded because of severe anoxic brain injury and 18 because of psychiatric/neurologic disease/learning disabilities. Of the 79 patients that the authors considered eligible for this study, only 57% were included. 19 patients were lost to follow-up of which six were transferred to further treatment and rehabilitation. In addition, 15 patients refused to participate. The patients included seemed to have less emotional complaints than generally reported. To compare, a review by Wilder Schaaf showed signs of depression in 14–45% (in this study 0%) and signs of anxiety in 13% to 61% (in this study 11%).8 Taking all this into account, we suspect that the current sample does not fully represent the population of OHCA survivors as a whole. There appears to be a selective drop out of patients with poorer prognosis. Therefore, we suspect that the overall percentage of patients with cognitive deficits after OHCA might well be higher than the reported 44%. It is important that patients, relatives and health care providers are aware of potential cognitive problems due to a cardiac arrest, because it can have high impact on a person’s functioning in daily life.5,6 Furthermore, patients and health workers should be aware of the treatment options in case of cognitive problems. For patients with other forms of acquired brain injury, cognitive rehabilitation has been proven to be effective.9 During cognitive rehabilitation http://dx.doi.org/10.1016/j.resuscitation.2014.09.022 0300-9572/© 2014 Elsevier Ireland Ltd. All rights reserved.
people learn in an interdisciplinary setting how to compensate for their cognitive impairments and how to use resources in order to retain optimal participation in society. Cognitive rehabilitation also comprises psycho-education to help patients with brain injury and their families how to cope with the cognitive and emotional consequences.10 There are no studies yet on the effectiveness of cognitive rehabilitation for patients with hypoxic brain injury due to cardiac arrest. We expect that OHCA survivors with cognitive deficits can benefit from cognitive rehabilitation interventions in the same way patients with other types of acquired brain injury do. Recently, an intervention that provided information on possible cognitive and emotional consequences three months after cardiac arrest was considered useful by both patients and health workers.11 However, more research on the effectiveness of cognitive rehabilitation after OHCA is needed. The extensive neuropsychological tests used in this study were able to detect even mild cognitive problems. These assessments took approximately 3 h, which makes them not suitable as a screening instrument for clinical daily practice. One could argue to use the Cerebral Performance Category (CPC), part of the Utstein template, as a screening. The CPC is a classification system that roughly estimates the functioning of the patient at time of hospital discharge. Torgersen et al. showed that the CPC is not capable of detecting mild cognitive problems and is therefore not suitable as a screening instrument for cognitive functioning.12,13 Which short cognitive screening instrument would be best for this specific patient group is not known yet. Future research should therefore investigate which concise screening instrument is the best with regard to validity, reliability, sensitivity and specificity. A well-known predictor of cognitive functioning after traumatic brain injury is coma duration.14 However, for survivors of OHCA, evidence on the relation between coma duration and outcome is scarce.15 The question whether induction of hypothermia protects against cognitive disabilities is not yet definitely solved.13,16,17 In this study the hypothermia was, in accordance with guidelines, administered to all patients comatose at time of ROSC.18 During the period of induced hypothermia the natural course of coma cannot be monitored, since the patients are being sedated during this procedure. The design of this study did not allow for randomization with regard to induced hypothermia and probably more patients with a relatively better prognosis were included. Therefore, in our opinion no final conclusions can be drawn yet on the causality between the studied prognostic factors and cognitive outcome.
A4
Editorial / Resuscitation 85 (2014) A3–A4
So, is it possible to draw conclusions for clinical daily practice? First of all, it is essential to be aware of the high incidence (up to 50%) of cognitive impairments in OHCA survivors. This aspect deserves attention in all survivors, but probably even more for patients with longer coma duration. We agree with Ørbo et al. that the threshold for referring OHCA survivors for neuropsychological assessment should be low. However, extensive cognitive testing is time consuming and sometimes stressful for patients. Therefore, there is an urgent need for a suitable and concise cognitive screening instrument. As long as there is no consensus on this, we advise to use locally available screening instruments which measure at least aspects of memory, attention and executive functioning. One could consider using the Montreal Cognitive Assessment (MOCA) as this cognitive screening showed already reasonable sensitivity/specificity in heart failure patients (.64/.66).19 Secondly, health care providers must be aware that there are (cognitive) rehabilitation programs available that can be of benefit for patients with cognitive impairments after a cardiac arrest. Local care chain arrangements can aid in streamlining referral from cardiac care to cognitive rehabilitation services. Conflict of interest statement The authors have no conflicts of interest. References 1. Van Alem AP, De Vos R, Schmand B, Koster RW. Cognitive impairment in survivors of out-of-hospital cardiac arrest. AHJ 2004;148:416–21. 2. Roine RO, Kajaste S, Kaste M. Neuropsychological sequelae of cardiac arrest. JAMA 1993;269:237–42. 3. Sauve MJ, Walker JA, Paul SM, Scheinman MM. Factors associated with cognitive recovery after cardiopulmonary resuscitation. Am J Crit Care 1996;5:27–39. 4. Moulaert VR, Verbunt JA, van Heugten CM, Wade DT. Cognitive impairments in survivors of out-of-hospital cardiac arrest: a systematic review. Resuscitation 2009;80:297–305. 5. Wachelder EM, Moulaert VR, van Heugten C, et al. Life after survival: longterm daily functioning and quality of life after an out-of-hospital cardiac arrest. Resuscitation 2009;80:517–22. 6. Mateen F, Josephs K, Trenerry M, et al. Long-term cognitive outcomes following out-of-hospital cardiac arrest: a population-based study. Neurology 2011;77:1438–45. 7. Ørbo M, Aslaksen PM, Larsby K, et al. Determinants of cognitive outcome in survivors of out-of-hospital cardiac arrest. Resuscitation 2014;85:1462–8. 8. Wilder Schaaf KP, Artman LK, Peberdy MA, et al. Anxiety, depression, and PTSD following cardiac arrest: a systematic review of the literature. Resuscitation 2013;84:873–7. 9. Van Heugten C, Gregório GW, Wade D. Evidence-based cognitive rehabilitation after acquired brain injury: a systematic review of content of treatment. Neuropsychol Rehabil 2012;22:653–73.
10. Daviet JC, Bonan I, Caire JM, et al. Therapeutic patient education for stroke survivors: non-pharmacological management. A literature review. Ann Phys Rehabil Med 2012;55:641–56. 11. Moulaert VR, van Haastregt JC, Wade DT, et al. ‘Stand still . . ., and move on’, an early neurologically-focused follow-up for cardiac arrest survivors and their caregivers: a process evaluation. BMC Health Serv Res 2014;14:34. 12. Langhelle A, Nolan J, Herlitz J, et al. Recommended guidelines for reviewing, reporting, and conducting research on post-resuscitation care: the Utstein style. Resuscitation 2005;66:271–83. 13. Torgersen J, Strand K, Bjelland TW, et al. Cognitive dysfunction and healthrelated quality of life after a cardiac arrest and therapeutic hypothermia. Acta Anaesthesiol Scand 2010;54:721–8. 14. Singh B, Murad MH, Prokop LJ, et al. Meta-analysis of Glasgow coma scale and simplified motor score in predicting traumatic brain injury outcomes. Brain Inj 2013;27:293–300. 15. Lim C, Verfaellie M, Schnyer D, Lafleche G, Alexander MP. Recovery, long-term cognitive outcome and quality of life following out-of-hospital cardiac arrest. J Rehabil Med 2014;46:691–7. 16. Nielsen N, Wetterslev J, Cronberg T, et al. Targeted temperature management at 33 ◦ C versus 36 ◦ C after cardiac arrest. N Engl J Med 2013;369: 2197–206. 17. Cronberg T, Lilja G, Rundgren M, Friberg H, Widner H. Long-term neurological outcome after cardiac arrest and therapeutic hypothermia. Resuscitation 2009;80:1119–23. 18. Peberdy MA, Callaway CW, Neumar RW, et al. American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science. Part 9: Post-cardiac arrest care. Circulation 2010;122: S768–86. 19. Hawkins MA, Gathright EC, Gunstad J, et al. The MoCA and MMSE as screeners for cognitive impairment in a heart failure population: a study with comprehensive neuropsychological testing. Heart Lung 2014;43:462–8.
Paulien H. Goossens a,b Rijnlands Rehabilitation Centre, Leiden, The Netherlands b Leiden University Medical Centre, Department of Orthopaedics, Physical Therapy and Rehabilitation, Leiden, The Netherlands a
Véronique R.M. Moulaert a,b,∗ Adelante, Centre of Expertise in Rehabilitation and Audiology, Hoensbroek, The Netherlands b CAPHRI School for Public Health and Primary Care, Department of Rehabilitation Medicine, Maastricht University, Maastricht, The Netherlands a
∗ Corresponding author. E-mail address: [email protected] (V.R.M. Moulaert)
28 September 2014
