Association between intraoperative hypotension and postoperative AKI: a literature review

• Autor(a) principal: Ana Isabel Ascensão Ferreira
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: https://hdl.handle.net/10216/128825
• topic: Ciências médicas e da saúde; Medical and Health sciences

Introduction: Intraoperative hypotension is a common complication of general anesthesia in patients undergoing surgery and has been associated with several adverse outcomes, among them postoperative acute kidney injury. This review intends to summarize the evidence in literature concerning the association between intraoperative hypotension and postoperative acute kidney injury in patients undergoing noncardiac surgery, as well as the underlying rationale for this relationship, including the role of patient-, anesthesia- and surgery-related factors and, mainly, the definition of intraoperative hypotension that best relates to acute kidney injury. Methods: A PubMed search was carried out for articles dated from 2000 to 2020 and with interest for the subject of this review. Selection of articles was based on key-words "intraoperative hypotension", "acute kidney injury", "surgery", and "association". In total, 226 articles were found, from which 35 were the foundation for the writing of this review. Results and Discussion: Intraoperative hypotension seems to cause postoperative acute kidney injury by inducing renal ischemic-reperfusion injury, although the underlying mechanism is not fully understood. Hypotension leads to hypoperfusion in the kidney, which triggers a series of mechanisms with the aim of restoring renal perfusion, thus renal blood flow and glomerular filtration rate. However, it was not clear whether duration and magnitude of hypotension directly related to acute kidney injury or if it was a consequence of preventive and treatment measures of hypotension. Based on recent studies, mean arterial pressure less than 55mmHg for increasing durations seems to increase the risk of postoperative acute kidney injury but none of them seemed to be able to find an association between acute kidney injury and the treatment of hypotension with fluid, vasopressor and inotropic administration. Despite being used to restore hypotension and hypoperfusion, there has been evidence of harm to the kidney, especially with normal saline solutions, hydroxyethyl starches and dopamine. Type and time of surgery and estimated blood loss are also predictors of the association between intraoperative hypotension and acute kidney injury. Conclusion: Long periods of mean arterial pressure values below certain thresholds strongly associate with increasing risk of postoperative acute kidney injury. Nevertheless, it remains unclear whether postoperative acute kidney injury is a direct consequence of intraoperative hypotension or a consequence of associated factors, such as fluid therapy and vasopressor and inotropic drugs. Further research is necessary to better understand this association. Key-words: Hypotension; Acute Kidney Injury; Surgical Procedures, Operative