Haptoglobin and Free Haemoglobin during Cardiac Surgery—is there a Link to Acute Kidney Injury?

Abstract

Acute kidney injury (AKI) is frequently observed after cardiac surgery (CS) with cardiopulmonary bypass (CPB). Multiple mechanisms underlie this phenomenon, including CPB-dependent haemolysis. Haemoglobin is released during haemolysis, and free haemoglobin (frHb) causes tubular cell injury after exceeding the binding capacity of haptoglobin (Hp). The objective of this study was to investigate the influence of perioperative changes in frHb and Hp levels on the incidence of CS-associated (CSA) AKI. After receiving local ethics committee approval and obtaining informed consent from our patients, we analysed the data pertaining to 154 patients undergoing CPB surgery. We recorded frHb and Hp concentrations pre-, intra- and postoperatively and defined AKI using the Kidney Disease Improving Global Outcomes (KDIGO) classification. We observed that frHb levels increased significantly during surgery and then decreased at ten hours thereafter and that Hp levels decreased during surgery and remained at low levels until the first postoperative day. We noted a moderate negative correlation between frHb and Hp levels. AKI was identified in 45.5% of patients; however, there was no significant difference in frHb or Hp levels between patients with and without AKI. We did not observe a relationship between frHb or Hp levels and CSA AKI and thus could not confirm the hypothesis that patients with higher baseline Hp concentrations experience a lower incidence of AKI than patients with lower baseline Hp concentrations.

Influence of hemoadsorption during cardiopulmonary bypass on blood vesicle count and function

“…Cardiac surgery, especially those utilizing CPB, is associated with the development of intravascular hemolysis, which appears to be linked with adverse clinical outcome [17]. High mechanical stress, different blood flow and pressure conditions, surface activation and cardiotomy suctioning can lead to excessive hemolysis during the perioperative course [18]. In our previous study [5], no effect on hemolysis between patients treated with hemoadsorption compared to the control group was found.…”

“…Interestingly, we found no correlation between hemolytic serum markers and vesicle counts in our patients. Hemolysis is caused by active destruction of erythrocytes, leading to the excessive release of hemoglobin as well as haptoglobin in the peripheral blood stream [18]. Thus, it is tempting to speculate that the count of microvesicles and apoptotic bodies concomitantly rises as well.…”

Redução de hemoglobina: risco para lesão renal aguda após revascularização do miocárdio

“…No período de pós-operatório de cirurgia cardíaca os percentuais elevados de LRA em cuidados críticos geralmente são decorrentes de diversos fatores como idade, uso de CEC prolongada, uso de drogas nefrotóxicas, IMC elevado, alteração das taxas de hemoglobina e transfusão sanguínea 16,17 . Condições também identificadas no presente estudo.…”

Four hours of veno-venous extracorporeal membrane oxygenation using bi-caval cannulation affects kidney function and induces moderate lung damage in a mouse model

“…Simultaneously, a significant increase in LDH was seen which may be explained due to hemolysis during ECMO. Hemolysis has previously been associated with impaired acute kidney failure after cardiopulmonary bypass [19]. Kidney failure during extracorporeal circulation is common and has multiple causes.…”