Cardiopulmonary bypass and edema: physiology and pathophysiology

Abstract

Edema is a common morbidity following cardiopulmonary bypass (CPB) and can result in injury to many organs, including the heart, lungs, and brain. Generalized edema is also common and can lead to increased post-operative hospital stay and other morbidities. Pediatric patients are more susceptible to post-CPB edema and the consequences are more severe for this population. Hemodilution and systemic inflammatory responses are two suspected causes of CPB-related edema; however, the mechanisms involved are far from understood. Also, the common strategies to improve edema have not been completely successful and there is a need for new strategies at maintaining a fluid balance of patients as close to physiological as possible, especially for pediatric patients. An integrative approach to understanding edema is necessary as the forces involved in fluid homeostasis are dynamic and interdependent. Therefore, this review will focus on the physiology of fluid homeostasis and the pathologies of fluid shifts during CPB which lead to general edema as well as tissue-specific edema.

A Safety and Efficacy Study of Tolvaptan Following Open Heart Surgery in 109 Cases

“…[11][12][13][14] Open heart surgery using cardiopulmonary bypass is often followed by symptoms such as circulatory inflammatory response, capillary hyperpermeability due to low body temperature, decreased intravascular colloid oncotic pressure due to hemodilution, and stromal edema as a result of decreased lymph flow. 15) Blood vasopressin concentration also increases after cardiac surgery because of hypotension during cardiopulmonary bypass and sympathetic nerve activation caused by operative stress. 16) Therefore, it is believed that reabsorption of water in the collecting tubules is excessive following open heart surgery.…”

Myocardial Ischemia in Congenital Heart Disease: A Review

“…With improvements in equipment and techniques, CPB has become safer and more reliable. However, it causes profound alterations in physiological fluid homeostasis [31]. The age and size of the patient, the underlying cardiac pathology, and the type of surgical techniques influence what perfusion methods are chosen and the construction of the CPB circuit [32].…”

Impact of Acute Normovolemic Hemodilution in Organ and Cell Structure

“…Data regarding the effects of ANH on lungs are mostly based on cardiopulmonary bypass studies. In such scenario, hemodilution and inflammatory response are associated with capillary leak and edema in different organs, including the lungs (Hirleman & Larson, 2008).…”