SGEM#347: It Don’t Matter to Me – Balanced Solution or Saline

Date: September 28th, 2021 Reference: Zampieri et al. Effect of Intravenous Fluid Treatment With a Balanced Solution vs 0.9% Saline Solution on Mortality in Critically Ill Patients: The BaSICS Randomized Clinical Trial. JAMA 2021 Guest Skeptic: Dr. Aaron Skolnik is an Assistant Professor of Emergency Medicine at the Mayo Clinic Alix School of Medicine and Consultant in the Department of Critical Care Medicine at Mayo Clinic Arizona. Board certified in Emergency Medicine, Medical Toxicology, Addiction Medicine, Internal Medicine-Critical Care, and Neurocritical Care, Aaron practices full time as a multidisciplinary intensivist. He is the Medical Director of Respiratory Care for Mayo Clinic Arizona and serves proudly as the medical student clerkship director for critical care medicine. Case:  A 66-year-old woman is brought in by EMS from home with lethargy and hypotension.  Chest x-ray is clear, labs are remarkable for a leukocytosis of 16,000 with left shift; exam is notable for left flank pain and costovertebral tenderness.  Straight catheter urinalysis is grossly cloudy, and pyuria is present on microscopy. Blood pressure is 85/50 mm Hg.  You wonder which intravenous (IV) fluid should you order? Background: In ten seasons of the SGEM we have not covered the issue of which IV solution is the best in critical ill patients. That includes both trauma patients and septic patients. The controversy has been long standing with the standard joke being that there is nothing “normal” about normal saline. Saline is a hypertonic acidotic fluid. Many critically ill patients receive intravenous crystalloids for volume expansion as part of their resuscitation.  Some bench work, observational studies, and now two large, unblinded, cluster-randomized single-center trials (SMART and SALT-ED) suggested a benefit to using balanced crystalloids (i.e. Lactated Ringer’s or Plasmalyte 148) over 0.9% saline. In the two large trials, this benefit was seen as a reduction in a composite outcome of major adverse kidney events within 30 days (MAKE-30). In the non-blinded SMART trial, there was no statistical difference in the individual components of the composite outcome (in-hospital death before 30 days, new renal replacement therapy or in creatinine >200% of baseline). The SALT-ED trial was also a single-centre unblinded trial, but the primary outcome was hospital free days. They reported no statistical difference between the two groups. Their secondary composite outcome of death, new renal-replacement therapy, or final serum creatinine >200% of baseline, was statistically better with balanced crystalloid vs saline. However, there was not a statistical difference in any of the individual components of the composite outcome. The BaSICS trial attempts to answer whether balanced solutions are superior to saline using a large, double-blind, factorial, multi-center randomized trial. Clinical Question: Does administration of a balanced solution (Plasma-Lyte 148) during intensive care unit (ICU) stay, compared with saline solution, result in improved 90-day survival in critically ill patients? Reference:  Zampieri et al. Effect of Intravenous Fluid Treatment With a Balanced Solution vs 0.9% Saline Solution on Mortality in Critically Ill Patients: The BaSICS Randomized Clinical Trial. JAMA 2021 Population: Adult patients admitted the ICU for more than 24 hours, needing at least one fluid expansion and with at least one risk factor for acute kidney injury (age over 65, hypotension, sepsis, required mechanical ventilation or non-invasive ventilation, oliguria or increased serum creatinine level, cirrhosis or acute liver failure) Exclusions: Required or expected to require renal replacement therapy within 6 hours of admission, severe electrolyte disturbances (sodium < 120 mmol/L or > 160 mmol/L), death considered imminent within 24 hours, suspected or confirmed brain death,