Hypoxic–Ischemic Encephalopathy

It is with great pleasure that we guest edit this issue on hypoxic–ischemic brain injury after cardiac arrest in Seminars in Neurology. We are indebted to our colleagues and friends who made this possible by offering their time and sharing their unique knowledge in this expanding field of medicine. Our authors represent a multitude of specialties, including anesthesiology, cardiology, critical care medicine, emergency medicine, internal medicine, neurology, neurophysiology, radiology, rehabilitation medicine, and more.

The first chapters provide a framework necessary in understanding how neurologic outcome after a cardiac arrest is affected by multiple organ factors and how improvements in the whole “chain of survival” have been integral in the increased survival rates reported globally.

Cardiac arrest is a dramatic medical event with high mortality and significant morbidity among survivors. We do not know the exact numbers that suffer from out-of-hospital cardiac arrest, but it may be that 1 in 10 of all deaths has this origin. Among those in whom cardiopulmonary resuscitation is initiated, the numbers are better known; with survival rates of ∼10%, there is still a lot of room for improvement. In the selected group of patients who make it all the way to the intensive care unit, however, survival rates are much better—approaching 50% in some centers. These previously neglected patients now get all the attention and medical care they deserve, including temperature management, emergency percutaneous coronary intervention, and prolonged care and observation time.

For this expanding group of critically ill patients, brain injury is the main challenge; consulting neurologists and neurointensivists are increasingly confronted with the difficult tasks of treating seizures and predicting final outcome. The current guidelines for neuroprognostication after cardiac arrest advocate the use of multiple methods to assess prognosis. In separate chapters, the practical aspects, strengths, and limitations of the most commonly used methods are explained in detail.

We still have limited knowledge on how hypoxic–ischemic brain injury affects the life of survivors and their close relatives and how their situation may be improved. This is a new and expanding field of research, which is highlighted in the last two chapters of this issue.

Teamwork, networking, and collaboration across borders are hallmarks of resuscitation science: all make this field of research so fascinating. We should thus continue on a path of collaborative efforts within postcardiac arrest care and use the networks that are being established to study intervention effects in large trials, which will improve life for cardiac arrest patients. We thank all the contributing authors and Dr. Greer for initiating this special issue.