Liver transplantation is the last line of therapy for severe end-stage liver disease and is increasingly performed throughout the world [
1,
2]. In the past decade, overall waiting list and post-transplant survival rates have increased alongside postoperative complications, a significant burden for patient care [
3,
4]. Due to the scarcity of human organs, strategies to improve recipients’ outcomes and organ survival are needed [
2,
4].
Liver transplant recipients suffer, on average, more than three postoperative complications, with over half of them being severe [
5,
6]. Several perioperative events and factors seem associated with the risk of complications [
5,
7‐
17]. Among these, perioperative fluid management has been associated with postoperative complications and proposed as an important aspect of care in high-risk recipients [
16,
18,
19]. A recent US survey revealed that more than 60% of anesthesiologists use either phlebotomy or normovolemic hemodilution to reduce blood transfusions and improve post-transplant outcomes, even though few of these interventions are supported by high-quality evidence [
20,
21]. The impact of perioperative fluid balance on postoperative complications is better understood in other surgical populations, with hundreds of different combinations of fluid management protocols and hemodynamic goals studied over the past decade [
22]. Perioperative fluid imbalance, defined as too little or too much fluid, was recently associated with a greater than 60% increase in postoperative complications after major abdominal surgery [
23]. Recent systematic reviews suggest that cardiac output-guided fluid administration, compared to either fixed restrictive or fixed liberal strategies, reduces postoperative complications by 20–30% in patients undergoing major surgery [
24,
25,
26], thus underscoring the significant role of fluid management in this population. More importantly, a recent multicenter clinical trial showed an increased incidence of acute renal failure when a fixed restrictive perioperative fluid strategy was compared to a liberal one during major abdominal surgery [
27]. Liver transplantations were not included in any of these studies.
Since evidence suggests that specific perioperative fluid management strategies can improve or worsen postoperative outcomes in many surgical populations, that such strategies are being used in the liver transplant population without high-quality data, and that physicians are eager to use perioperative fluid and blood volume management strategies to improve outcomes in this population, the role of perioperative fluid management strategies in liver transplantation needs to be better understood [
5,
7‐
16,
20,
21,
23‐
25,
26]. Therefore, we will conduct a systematic review aimed at evaluating the effects of a restrictive perioperative fluid management strategy compared to a liberal strategy on clinically significant outcomes in adult patients undergoing liver transplantation.