Isotonic Solutions and Major Adverse Renal Events Trial in the Non-Medical Intensive Care Unit (SMART-SURG) (SMART-SURG)

Isotonic Solutions and Major Adverse Renal Events Trial in the Non-Medical Intensive Care Unit (SMART-SURG)

The administration of intravenous fluids is ubiquitous in the care of the critically ill. Commonly available isotonic crystalloid solutions contain a broad spectrum electrolyte compositions including a range chloride concentrations. Recent studies have associated solutions with supraphysiologic chloride content with hyperchloremia, metabolic acidosis and renal vasoconstriction, acute kidney injury and renal replacement therapy, and increased mortality but no large, randomized-controlled trials have been conducted. SMART-SURG will be a large, cluster-randomized, multiple-crossover trial enrolling critically ill patients from the non-medical ICUs at Vanderbilt University from October 2015 until April 2017. The primary endpoint will be the incidence of Major Adverse Kidney Events in 30 days after enrollment (MAKE30 is the composite of death, new renal replacement, or persistent renal dysfunction at discharge).

SMART-SURG is a large, cluster-randomized, multiple-crossover trial of 0.9% saline versus physiologically-balanced isotonic crystalloids (Lactated Ringers or Plasma-Lyte© A) with regard to the incidence of major adverse kidney events by 30 days in patients admitted to non-medical intensive care units. All patients admitted to participating non-medical intensive care units at Vanderbilt University medical center who are 18 years or older will be enrolled. The study will occur in one-month blocks. Each participating ICU will be randomized to an initial fluid group (0.9% saline or physiologically balanced isotonic crystalloids). The assigned fluid will be used exclusively for all patients receiving isotonic crystalloid for the duration of the month-long block (except in the presence of pre-specified contraindications). The assigned study fluid will switch at the end of each month-long block such that half of the months are assigned to 0.9% saline and half of the months to physiologically balance fluid. The primary endpoint will be major adverse kidney events by 30 days (MAKE30 is the composite of death, new renal replacement therapy, or persistent renal dysfunction at discharge). All aspects of study design, intervention, and data collection will be harmonized with an ongoing, independent study addressing the same question in the medical intensive care unit at Vanderbilt University during a similar study period (SMART-MED). A pre-specified data analysis plan will dictate the harmonized analysis of SMART-MED and SMART-SURG.

Patients in an ICU block randomized to physiologically-balanced isotonic fluid will receive 0.9% Saline whenever isotonic intravenous fluid administration is ordered by the treating provider.

Patients in an ICU block randomized to physiologically-balanced isotonic fluid will receive Plasma-Lyte© A or Lactated Ringer's whenever isotonic intravenous fluid administration is ordered by the treating provider.

The primary outcome was the proportion of patients who met one or more criteria for a major adverse kidney event within 30 days - the composite of death, new receipt of renal-replacement therapy, or persistent renal dysfunction (defined as a final inpatient creatinine value ≥200% of the baseline value) - all censored at hospital discharge or 30 days after enrollment, whichever came first.

Inclusion Criteria: Admitted to a participating non-medical intensive care unit (ICU) at Vanderbilt University Medical Center Exclusion Criteria: Age<18 years old

Finfer S, Liu B, Taylor C, Bellomo R, Billot L, Cook D, Du B, McArthur C, Myburgh J; SAFE TRIPS Investigators. Resuscitation fluid use in critically ill adults: an international cross-sectional study in 391 intensive care units. Crit Care. 2010;14(5):R185. doi: 10.1186/cc9293. Epub 2010 Oct 15.

Yunos NM, Kim IB, Bellomo R, Bailey M, Ho L, Story D, Gutteridge GA, Hart GK. The biochemical effects of restricting chloride-rich fluids in intensive care. Crit Care Med. 2011 Nov;39(11):2419-24. doi: 10.1097/CCM.0b013e31822571e5.

Yunos NM, Bellomo R, Hegarty C, Story D, Ho L, Bailey M. Association between a chloride-liberal vs chloride-restrictive intravenous fluid administration strategy and kidney injury in critically ill adults. JAMA. 2012 Oct 17;308(15):1566-72. doi: 10.1001/jama.2012.13356.

Lombardo S, Smith MC, Semler MW, Wang L, Dear ML, Lindsell CJ, Freundlich RE, Guillamondegui OD, Self WH, Rice TW; Isotonic Solutions and Major Adverse Renal Events Trial (SMART) Investigators and Vanderbilt Learning Healthcare System Platform Investigators. Balanced Crystalloid versus Saline in Adults with Traumatic Brain Injury: Secondary Analysis of a Clinical Trial. J Neurotrauma. 2022 Sep;39(17-18):1159-1167. doi: 10.1089/neu.2021.0465.

Semler MW, Self WH, Wanderer JP, Ehrenfeld JM, Wang L, Byrne DW, Stollings JL, Kumar AB, Hughes CG, Hernandez A, Guillamondegui OD, May AK, Weavind L, Casey JD, Siew ED, Shaw AD, Bernard GR, Rice TW; SMART Investigators and the Pragmatic Critical Care Research Group. Balanced Crystalloids versus Saline in Critically Ill Adults. N Engl J Med. 2018 Mar 1;378(9):829-839. doi: 10.1056/NEJMoa1711584. Epub 2018 Feb 27.

Semler MW, Self WH, Wang L, Byrne DW, Wanderer JP, Ehrenfeld JM, Stollings JL, Kumar AB, Hernandez A, Guillamondegui OD, May AK, Siew ED, Shaw AD, Bernard GR, Rice TW; Isotonic Solutions and Major Adverse Renal Events Trial (SMART) Investigators; Pragmatic Critical Care Research Group. Balanced crystalloids versus saline in the intensive care unit: study protocol for a cluster-randomized, multiple-crossover trial. Trials. 2017 Mar 16;18(1):129. doi: 10.1186/s13063-017-1871-1.