Background and Goal of Study: The administration of intravenous (IV) crystalloid fluid is a ubiquitous intervention in patients undergoing major surgery. We conducted a prospective Phase 4, single centre blinded study investigating the safety and efficacy of using Saline (0.9%) (Baxter Healthcare, Australia) or Plasma-lyte® 148 (Baxter Healthcare, Australia) as perioperative fluid therapy in adult patients undergoing major surgery.

Materials and Methods: Blinded study fluid was used for all intraoperative and postoperative crystalloid therapy until hospital discharge. Perioperative management including use of colloids, blood and other blood products were at the discretion of the attending anaesthesia and surgical teams. 

Results and Discussion: 1100 patients were recruited. Patients in both groups had similar baseline characteristics. Intraoperatively there were no significant differences in the types of surgery. 1100 patients (100%) received intraoperative Trial fluid; 746 patients received Plasma-lyte® 148 and 634 patients received Saline (0.9%). The median (IQR) amount Trial fluid received was greater in the Plasma-lyte® group: 2000ml (1000:2000) vs. 1925 ml (1000:2000) in the Saline group (p=0.007). Duration of surgery was similar in both groups. Patients receiving Saline a developed a transient hyperchloraemic metabolic acidosis on postoperative Day 1 compared to patients receiving Plasma-lyte®. Postoperatively, there were no differences in the incidence of AKI between the group: 52 (10.9%) patients in the Plasma-lyte® group developed a postoperative AKI compared to 59 (9.3%) patients in the saline group (p=0.41, 95%CI: 0.6 to 1.2). Patients who developed an AKI were older, had larger volumes of fluid both intraoperatively and on postoperative Day 1, and had greater fluid balances intraoperatively and on postoperative Day 1. There were no differences in the development of postoperative complications between the groups. Median (IQR) length of stay was almost identical in both groups (Plasma-lyte® 5.0 days (2.77:8.98) vs. Saline 5.0 days (2.81:9.04).

Conclusions: In patients undergoing major surgery, there were no differences in length of hospital stay, incidence of AKI or the development of postoperative complications in patients who received Plasma-lyte® or Saline for perioperative fluid intervention. Patients who received Saline developed a transient hyperchloraemic metabolic acidosis on postoperative Day 1.

Saline (0.9%) vs. Plasma-Lyte® 148 fluid intervention trial in major surgery patients (The SPLIT- Major Surgery study): a single-centred randomised double-blind trial