Hypertonic saline for fluid resuscitation in ICU patients post-cardiac surgery (HERACLES): a double-blind randomized controlled clinical trial.

PURPOSE: Recent evidence questions a liberal approach to fluid resuscitation in intensive care unit (ICU) patients. Here, we assess whether use of hypertonic saline applied as single infusion at ICU admission after cardiac surgery can reduce cumulative perioperative fluid volume. METHODS: Prospective randomized double-blind single-center clinical trial investigates effects of a single infusion of hypertonic saline (HS) versus normal saline (comparator). Primary endpoint was the cumulative amount of fluid administered in patients in the hypertonic saline versus the 0.9% saline groups (during ICU stay). Upon ICU admission, patients received a single infusion of 5 ml/kg body weight of 7.3% NaCl (or 0.9% NaCl) over 60 min. Patients undergoing cardiac surgery for elective valvular and/or coronary heart disease were included. Patients with advanced organ dysfunction, infection, and/or patients on chronic steroid medication were excluded. RESULTS: A total of 101 patients were randomized to receive the study intervention (HS n = 53, NS n = 48). Cumulative fluid intake on the ICU (primary endpoint) did not differ between the HS and the NS groups [median 3193 ml (IQR 2052-4333 ml) vs. 3345 ml (IQR 2332-5043 ml)]. Postoperative urinary output until ICU discharge was increased in HS-treated patients [median 2250 ml (IQR 1640-2690 ml) vs. 1545 ml (IQR 1087-1976 ml)], and ICU fluid balance was lower in the HS group when compared to the NS group [296 ml (IQR - 441 to 1412 ml) vs. 1137 ml (IQR 322-2660 ml)]. CONCLUSION: In a monocentric prospective double-blind randomized clinical trial, we observed that hypertonic saline did not reduce the total fluid volume administered on the ICU in critically ill cardiac surgery patients. Hypertonic saline infusion was associated with timely increase in urinary output. Variations in electrolyte and acid-base homeostasis were transient, but substantial in all patients.

Hypertonic saline for fluid resuscitation after cardiac surgery (HERACLES): study protocol for a preliminary randomised controlled clinical trial.

BACKGROUND: Intraoperative and postoperative management of cardiac surgery patients is complex, involving the application of differential vasopressors and volume therapy. It has been shown that a positive fluid balance has a major impact on postoperative outcome. Today, the advantages and disadvantages of buffered crystalloid solutes are a topic of controversy, with no consensus being reached so far. The use of hypertonic saline (HS) has shown promising results with respect to lower total fluid balance and postoperative weight gain in critically ill patients in preliminary studies. However, collection of more data on HS in critically ill patients seems warranted. This preliminary study aims to investigate whether fluid resuscitation using HS in patients following cardiac surgery results in less total fluid volume being administered. METHODS: In a prospective double-blind randomised controlled clinical trial, we aim to recruit 96 patients undergoing elective cardiac surgery for ischaemic and/or valvular heart disease. After postoperative admission to the intensive care unit (ICU), patients will be randomly assigned to receive 5 ml/kg ideal body weight HS (7.3% NaCl) or normal saline (NS, 0.9% NaCl) infused within 60 min. Blood and urine samples will be collected preoperatively and postoperatively up to day 6 to assess changes in renal, cardiac, inflammatory, acid-base, and electrolyte parameters. Additionally, we will perform renal ultrasonography studies to assess renal blood flow before, during, and after infusion, and we will measure total body water using preoperative and postoperative body composition analysis (bioimpedance). Patients will be followed up for 90 days. DISCUSSION: The key objective of this study is to assess the cumulative amount of fluid administered in the intervention (HS) group versus control (NS) group during the ICU stay. In this preliminary, prospective, randomised controlled clinical trial we will test the hypothesis that use of HS results in less total fluids infused and less postoperative weight gain when compared to the standard of intensive care in cardiac surgery patients. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03280745 . Registered on 12 September 2017.