A reperfusion injury is damage to the body that happens when blood flow is restored after a period of ischemia, where no blood, oxygen, or nutrients are reaching the cells in a given location. Some special circumstances need to be present for reperfusion injury to occur, and this is most commonly seen in the wake of severe crush injuries or myocardial infarction. Doctors can take some steps to identify risk factors and help present such injuries in their patients, and treatments are available.
Also known as a hyperperfusion injury, reperfusion injuries occur when an area of the body is suddenly flooded with blood at high volume and pressures as doctors manage to restore the blood flow. This can overload the tissues, causing a cascade of symptoms. One issue with a reperfusion injury is oxidative stress, which can damage cell membranes, DNA, and other structures, leading to tissue death and other complications. The rapid blood flow also carries along a flood of white blood cells, triggering an inflammatory response that may overload the tissue.
Sometimes, rather than causing an injury, a restoration of blood can highlight an underlying injury that was not noticed. This is common in crush injuries, where the ischemia may temporarily prevent symptoms, but once the blood is directed back into the damaged area, the patient can experience acute pain and other symptoms as the tissue reperfuses. Likewise, damage to the brain caused by injuries and strokes can emerge when a doctor successfully treats the ischemia and gets blood moving into that area of the brain again.
Some techniques to address reperfusion injury can include clamping to selectively control the flow of blood, allowing doctors to slowly reperfuse tissue rather than flooding it with fresh blood, along with trying to minimize the amount of time tissue is without a supply of blood. The longer cells remain ischemic, the greater the risk of perfusion injury can be. If a patient does experience tissue damage when the supply of blood is restored, it may be necessary to provide surgical or other treatments for tissue death and related complications.
The documented history of reperfusion injury in crush injuries and similar situations has led a number of hospitals to institute clear protocols for handling such cases. These are designed to provide guidelines for care providers so they can provide the most appropriate and timely interventions for their patients, with the goal of preventing complications by being proactive with patient treatment.