Acute Coronary Syndrome
Over 80% of patients resuscitated from cardiac arrest collapsed as a result of acute coronary disease. Recognizing which patients need emergent coronary angiography (e.g. STEMI) and which can have delayed evaluation (e.g. normal ECG with stable blood pressure) is an active area of research in Cardiology. The treatment of acute coronary disease has to occur in parallel with treatment of other organ dysfunction. Interventionalists and intensivists who are comfortable with this patient population are critical. Some patients with severe cardiogenic shock may require invasive or extracorporeal mechanical circulatory support.
Cerebral Edema
As many as 25% of patients have brain swelling after cardiac arrest. When severe, this can lead to neurological devastation and death. Routine imaging of the brain is a key part of the evaluation. Some patients may need specialized monitoring from neurosurgical services. Management may include hypertonic fluids, specific ventilator management and careful balance of intake and output.
Seizures
About 10% of patients have visible seizures, but another 20-30% have electrographic seizures that are only detected with EEG monitoring (nonconvulsive seizures). True epileptiform seizures must be distinguished from myoclonic jerks which have different appearance on EEG. If seizures continue for an extended length of time (status epilepticus), brain injury can worsen Continuous EEG monitoring allows more rapid detection of seizures and detection of nonconvulsive status epilepticus. Successful control of seizures when an aggressive escalation of anticonvulsant
Myoclonus
Many patients will have rhythmic jerks of the face and torso, sometimes including the extremities. The eyes may open briefly. Sometimes these whole-body jerks are a sign of very severe brain damage. Sometimes they are a seizure. Sometimes they are treatable. Sorting out which one is affecting a particular patient can require multiple evaluations by neurologists and EEG. In years past, these were considered a sign of irreversible brain damage, but now aggressive care and attempts to identify the treatable cases has resulted in some good outcomes.
Neurological Prognostication
Nationwide, the most common circumstance leading to in-hospital death after cardiac arrest is withdrawal of life sustaining treatment because of a poor neurological prognosis. This is the final disposition for about 60% of patients in national samples. No single test or exam can determine this prognosis. Systematic collection of data over the first few days, including EEG, evoked potentials, MRI, and serial examinations can provide the best quantitative information to help families make these difficult choices. Making these decisions with partial information, partially interpreted information, or inadequate periods of observation has to be avoided.
Multiple-organ Failure
The entire body of the cardiac arrest patient experiences ischemia. Every organ is at risk of damage. Support for each organ may require a specialist or an intervention. For example, about 10% of patients develop acute renal failure from ischemia, perhaps complicated by IV dye required for evaluation, is usually reversible. Needing hemodialysis for a period of time actually does not reduce the final quality of survival for post-cardiac arrest patients. Similarly, pneumonia and acute lung injury are seen in 30-40% of patients. However, post-cardiac arrest patients rarely die from hypoxemia or hypoventilation with expert pulmonary care.
Secondary Prevention
Survivors of cardiac arrest are a population who may most benefit from implantable cardiac defibrillators or other secondary prophylaxis. Evaluation and potentially treatment by an electrophysiologist may be required.
Rehabilitation
Recovery starts in the intensive care unit. Early physical therapy and occupational therapy can lead to evaluation for rehabilitation. A number of subtle mental and physical problems persist even when patients wake up after cardiac arrest. Some neuropsychological screening should be part of the evaluation for patients who awaken. Specific plans of care are available to address memory problems, executive function, fatigue and other complaints. Physical Medicine and Rehabilitation finds that some post-cardiac arrest patients benefit from an inpatient rehabilitation stay immediately after the acute hospitalization.