CPR induced consciousness is characterized by a patient waking up, moving their limbs, or even fighting responders during compressions. Typically, when the providers stop compressions, either for a pulse check or because of assumed ROSC, the patient stops moving and again goes unresponsive. This has been described in both pre-hospital and hospital settings, and with improvement of CPR quality, will occur more frequently.
What is CPR-Induced Consciousness?
CPR Induced Consciousness occurs when CPR generates sufficient cerebral perfusion pressure (CPP) to allow for consciousness. CPP correlates closely with brain oxygenation. In 1995, the topic was first asked if patients should be sedated during CPR, but this was based off the idea that they patient may be conscious during the peri-arrest episode, not during the actual resuscitation itself.
In a prospective study of 2060 victims of cardiac arrest, 46% of survivors reported memories of the CPR. Single images were placed on shelves visible to the patient to assess visual awareness during resuscitation, and all survivors were interviewed in a two step interview process. Most patients recalled themes of fear, bright light, violence or a sensation of being persecuted, seeing family, or recalling events that occured after ROSC. 2% actually recalled seeing and hearing actual events related to their resuscitation, including one episode that was verifiably accurate. (AWARE, S. Parnia et al. / Resuscitation 85 (2014) 1799–1805)
A systematic review of case reports and published articles in 2015 found only 10 cases of actual awareness, excluding all near-death experiences, animal models, and non-purposeful movements. In 5 of 10 cases, CPR was initiated immediately and occured in-hospital. In all out-of-hospital cases, CPR began within 1-minute. All patients in the review had purposeful arm movements, while there was also a range of other findings including eye opening, localizing to painful stimuli, and even verbal communication, including adhering to instructions being given.
A retrospective review of data from Victoria, Australia in 2017 found that CPR-Induced Consciousness is reported in approximately 0.7% of out-of-hospital cases, and increased over time from 2008 to 2014, presumptively from improvements in CPR quality. 87% of patients had body movement, 29% had vocalizations, and 20% had eye opening.
Management of CPR Induced Consciousness:
Due to higher-quality CPR, an unintended consequence has been CPR-induced consciousness, leading to some EMS agencies to creating protocols for sedation during CPR. These include IV or IM Ketamine (0.5-2mg) as well as midazolam. (Rice, 2016).
There is data showing that treating CPRIC is not associated with worsening outcomes or increased mortality, so you should consider treating CPRIC with either a small, repeated benzodiazapine or ketamine boluses.
Pulmonary embolisms present with a broad variety of symptoms from chest pain to shortness of breath, and even fevers. Common exam findings include tachypnea and tachycardia. Risk factors include recent surgery, trauma, prolonged immobility, active cancer, birth control pills or hormone replacement therapy, or a history of prior embolism.
Pulmonary Embolism is the Arresting Patient
Patients who arrest with a strong suspicion of pulmonary embolism may be treated with TPA. Bedside ultrasound should be used to help rule out alternative causes, such as tamponade or aortic dissection. Bedside ultrasound should also be used to evaluate for right heart strain prior to TPA.
The initial dose of TPA in a cardiac arrest varies depending on what study is being evaluated. Some doses include an initial bolus of 10-15mg of TPA followed by an influsion of 85-90mg over an hour. Local protocol calls for a single bolus of 50mg over 2 minutes in cardiac arrest. This should be followed by at least 15-20 additional minutes of CPR to allow for TPA to circulate. A second dose could be considered.
Current data shows that there is no difference in outcome when comparing patients who do and do not receive TPA during cardiac arrest. The same data also does not show increased risk of severe bleeding when comparing these populations. Undifferentiated cardiac arrest is NOT an indication for TPA.