postischemische

Postischemische, or postischemic, describes conditions and tissue states that arise after an ischemic episode when blood flow is restored. In medical literature, the term is often used to denote reperfusion injury, the paradoxical tissue damage that can follow restoration of circulation.

Pathophysiology is multifactorial. Reperfusion introduces oxygen leading to the production of reactive oxygen species, activation of neutrophils and the complement system, calcium overload, and mitochondrial dysfunction. Endothelial injury and microvascular obstruction can cause edema and impaired perfusion, further aggravating tissue injury even after blood flow resumes.

Clinical relevance is broad. Postischemic injury is a key concern in myocardial infarction treated with reperfusion therapy, ischemic stroke where recanalization is achieved, and surgeries or events involving kidneys, liver, intestines, or transplanted organs. The extent of injury often depends on the duration of ischemia, the tissue involved, and the speed and manner of reperfusion.

Diagnostics and biomarkers are used to assess tissue damage and organ function. Elevated cardiac enzymes, such as troponin or CK-MB, may reflect myocardial reperfusion injury. Kidney injury markers (e.g., NGAL) and imaging findings such as edema can indicate postischemic damage in non-cardiac tissues.

Management aims to minimize reperfusion injury while restoring circulation. Approaches include controlled reperfusion, ischemic preconditioning or postconditioning, antioxidant and anti-inflammatory strategies, and meticulous hemodynamic support. Experimental therapies explore remote ischemic conditioning and mitochondrial protection.

See also: ischemia-reperfusion injury, reperfusion injury, ischemia, organ transplantation.