High mean arterial pressure target to improve sepsis-associated acute kidney injury in patients with prior hypertension: a feasibility study

Comprehensive Management of Blood Pressure in Patients with Septic AKI

Acute kidney injury (AKI) is one of the serious complications of sepsis in clinical practice, and is an important cause of prolonged hospitalization, death, increased medical costs, and a huge medical burden to society. The pathogenesis of AKI associated with sepsis is relatively complex and includes hemodynamic abnormalities due to inflammatory response, oxidative stress, and shock, which subsequently cause a decrease in renal perfusion pressure and eventually lead to ischemia and hypoxia in renal tissue. Active clinical correction of hypotension can effectively improve renal microcirculatory disorders and promote the recovery of renal function. Furthermore, it has been found that in patients with a previous history of hypertension, small changes in blood pressure may be even more deleterious for kidney function. Therefore, the management of blood pressure in patients with sepsis-related AKI will directly affect the short-term and long-term renal function prognosis. This review summarizes the pathophysiological mechanisms of microcirculatory disorders affecting renal function, fluid management, vasopressor, the clinical blood pressure target, and kidney replacement therapy to provide a reference for the clinical management of sepsis-related AKI, thereby promoting the recovery of renal function for the purpose of improving patient prognosis.

Higher blood pressure versus normotension targets to prevent acute kidney injury: a systematic review and meta-regression of randomized controlled trials

BACKGROUND

Renal hypoperfusion is one of the most common causes of acute kidney injury (AKI), especially in shock and perioperative patients. An optimal blood pressure (BP) target to prevent AKI remains undetermined. We conducted a systematic review and meta-analysis of available randomized clinical trial (RCT) results to address this knowledge gap.

METHODS

From inception to May 13, 2022, we searched Ovid Medline, EMBASE, Cochrane Library, SCOPUS, clinicaltrials.gov, and WHO ICTRP for RCTs comparing higher BP target versus normotension in hemodynamically unstable patients (shock, post-cardiac arrest, or surgery patients). The outcomes of interest were post-intervention AKI rate and renal replacement therapy (RRT) rate. Two investigators independently screened the citations and reviewed the full texts for eligible studies according to a predefined form.

RESULTS

Twelve trials were included, enrolling a total of 5759 participants, with shock, non-cardiac, and cardiac surgery patients accounting for 3282 (57.0%), 1687 (29.3%) and 790 (13.7%) patients, respectively. Compared to lower mean arterial blood pressure (MAP) targets that served as normotension, targeting higher MAP had no significant effect on AKI rates in shock (RR [95% CI] = 1.10 [0.93, 1.29]), in cardiac-surgery (RR [95% CI] = 0.87 [0.73, 1.03]) and non-cardiac surgery patients (RR [95% CI] = 1.25 [0.98, 1.60]) using random-effects meta-analyses. In shock patients with premorbid hypertension, however, targeting MAP above 70 mmHg resulted in significantly lower RRT risks, RR [95%CI] = 1.20 [1.03, 1.41], p < 0.05.

CONCLUSIONS

Targeting a higher MAP in shock or perioperative patients may not be superior to normotension, except in shock patients with premorbid hypertension. Further studies are needed to assess the effects of a high MAP target to preventing AKI in hypertensive patients across common settings of hemodynamic instability. Trial registration This systematic review has been registered on PROSPERO ( CRD42021286203 ) on November 19, 2021, prior to data extraction and analysis.

Sepsis Management for the Nephrologist

The definition of sepsis has evolved significantly over the past three decades. Today, sepsis is defined as a dysregulated host immune response to microbial invasion leading to end organ dysfunction. Septic shock is characterized by hypotension requiring vasopressors after adequate fluid resuscitation with elevated lactate. Early recognition and intervention remain hallmarks for sepsis management. We addressed the current literature and assimilated thought regarding optimum initial resuscitation of the patient with sepsis. A nuanced understanding of the physiology of lactate is provided in our review. Physiologic and practical knowledge of steroid and vasopressor therapy for sepsis is crucial and addressed. As blood purification may interest the nephrologist treating sepsis, we have also added a brief discussion of its status.