Unconscious And Aware
April 30, 2019
Research into the mind and body connection at death raises significant application to administering CPR following cardiac arrest.
A seminal study (Parnia, et al.1), commencing in 2008, tracked 2,060 cases of cardiac arrest (CA) in 15 hospitals across three countries. Approximately 40 percent (140) of the 330 patients who survived CA agreed to interviews about their experience. The group of scientists involved in the AWARE study (AWAke during REsuscitation) published their findings in the journal Resuscitation (2014).
According to their results, seven major cognitive themes were prevalent among those who had memories of the experience (fear; animals/plants; bright light; violence/persecution; déjà vu; family; and recalling events post-CA), while a much smaller proportion of the survivors described near-death experiences (NDEs) and actual events related to their resuscitation.
Their conclusion supported other recent studies: Consciousness may be present despite clinically undetectable consciousness.
What makes this so unusual and applicable to emergency dispatch and bystander CPR? Awareness during CPR is an extremely rare event.
A second article (Olaussen, et al.2) published one year later in Resuscitation supports evidence of CPR generating sufficient cerebral perfusion pressure to make the patient conscious.
This study, a literature review, yielded 1,997 unique records of which 50 abstracts were reviewed and, of these, nine reports involving 10 patients were relevant to the study. Four patients had out-of-hospital cardiac arrest, and six had cardiac arrest within a hospital setting. Six of the patients had CPR performed by mechanical devices, and three of these patients were sedated. Four survived but varying levels of consciousness were described in all reports and, similar to the earlier study (Parnia, et al.), included purposeful arm movements, verbal communication, and interfering with resuscitation efforts. Physical and chemical restraints were management strategies offered to six patients.
That’s where the problem comes in. While CPR-induced consciousness is rare, it does occur and there is a likelihood that it will increase due to high quality chest compressions and extended CPR times, and the availability of newer treatment alternatives. At this point, however, as concluded in the second study, the lack of literature on CPR-induced consciousness adversely limits development of evidence-based management guidelines. Until more research is available, consensus-derived guidelines are the practical solution (such as a clear definition of CPR-induced consciousness and the use of physical and chemical restraints).
The International Academies of Emergency Dispatch® (IAED™) advocates high-performance CPR (HP CPR), a technique that focuses on providing high quality CPR by incorporating minimal breaks in compressions, full chest recoil, adequate compression depth, and adequate compression rate.
As the focus continues, it’s inevitable that we’ll see more of what used to be a rare event, according to Brett Patterson, IAED Academics & Standards Associate and Chair of the Medical Council of Standards.
“Patients are showing signs of consciousness during compressions even without any electrical activity or spontaneous contractions of the heart,” Patterson said. “Essentially, the quality compressions alone are circulating enough blood during the resuscitation event to facilitate consciousness.”
Patterson advises that EMDs understand that while a patient resisting CPR (moaning, pushing rescuer away, etc.) is cause for stopping compressions, if the patient then immediately becomes unresponsive when the compressions stop, and is not breathing effectively, CPR needs to be started again immediately.
“This sort of thing will be rare in our environment as lay folks don’t have the same skill set and the advantages that come with intense practice and quality improvement that responders do, but it is possible, especially when CPR is started immediately after an arrest and the CPR quality is exceptional,” he said.
1 Parnia S, Spearpoint K, de Vos G, et al. “AWARE-AWAreness during Resuscitation - A prospective study.” Resuscitation. 2014; Oct. 6. https://www.resuscitationjournal.com/article/S0300-9572(14)00739-4/abstract (accessed Nov. 7, 2018).
2 Olaussen A, Shepherd M, Nehme Z, Smith K, Bernard S, Mitra B. “Return of Consciousness during Resuscitation.” Resuscitation. 2015; Jan. https://pdfs.semanticscholar.org/0832/fe5154064f7135fed0f47014334f386e2359.pdf (accessed Nov. 7, 2018).
The following are case reports of CPR-induced consciousness. The second case report includes a 30-second video.
A 52-year-old male presented as a witnessed out-of-hospital cardiac arrest (OHCA). During CPR the patient began to exhibit signs of life including severe agitation and thrashing of his limbs while CPR was ongoing for ventricular fibrillation prior to defibrillation. Resuscitation became considerably more complicated due to the violent and counterintuitive motions done by the patient during their own resuscitation. Despite the atypical presentation of cardiac arrest the patient was successfully resuscitated employing high quality CPR, standard advanced life support (ALS) care as well as two double sequential external defibrillation shocks. The patient underwent emergency percutaneous coronary intervention (PCI) for a 100 percent occlusion of his left anterior descending artery (LAD). The patient returned home three days later fully recovered with a Cerebral Performance Score of 1.
Pound J, Verbeek PR, Cheskes S. “CPR Induced Consciousness During Out-of-Hospital Cardiac Arrest: A Case Report on an Emergency Phenomenon.” Prehospital Emergency Care. 2017; March-April. https://www.ncbi.nlm.nih.gov/pubmed/term=CPR+Induced+Consciousness+During+Out-of-Hospital+Cardiac+Arrest%3A+A+Case+Report+on+an+Emerging+Phenomenon (accessed Nov. 9, 2018).
An 82-year-old healthy and high functioning gentleman had been feeling unwell for several days with progressive dyspnea. He walked into the emergency department with his son, sat down in a chair in ambulatory triage, and promptly became unresponsive. He was wheeled into the resus bay where he was apneic and pulseless with a PEA rhythm. Cardiac arrest care included chest compressions, laryngeal mask ventilation, epinephrine, calcium, and bicarbonate, without ROSC. Throughout the period of cardiac arrest care, including during periods of cardiac standstill, the patient became awake during chest compressions and opened his eyes, tracked staff, made purposeful movements toward the laryngeal tube and toward the person doing chest compressions as well as flailing, distressed lower extremity movements. 100 mg ketamine was given to good effect, repeated once. After 75 minutes, the decision was made with the patient’s son that further resuscitative efforts were unlikely to be successful. Chest compressions were halted, and the patient was pronounced deceased.
Strayer R. “CPR Induced Consciousness: A 30 Second Video.” Emergency Medicine Updates. 2018; April 27. https://emupdates.com/cpric/ (accessed Nov. 9, 2018).