a) What do you understand by the term ‘balanced crystalloid solution’? (10% marks)
b) Compare and contrast the constituents of normal saline and any one balanced crystalloid solution. (20% marks)
c) Discuss the advantages and disadvantages of balanced crystalloid solutions and normal saline in the fluid management of diabetic ketoacidosis. (70% marks)
a) "Balanced crystalloids have a sodium, potassium, and chloride content closer to that of extracellular fluid and, when given intravenously, have fewer adverse effects on acid–base balance." Semler & Kellum, 2019
Any from the broad range of available balanced crystalloids should have been appropriate here, and the real trick would have been to remember the exact goddamn numbers for the chloride and sodium concentrations. The table presented here (cut-and-pasted from Semler & Kellum) is available for reference.
|0.9% sodium chloride||154||154||308|
c) Advantages and disadvantages of normal saline and balanced crystalloid in the management of DKA:
You could have answered this as a table, or as a set of pointform notes. Observe:
|Normal saline||Balanced crystalloid|
Or, in point form:
Semler, Matthew W., and John A. Kellum. "Balanced crystalloid solutions." American journal of respiratory and critical care medicine 199.8 (2019): 952-960.
Curran, Jeffrey D., et al. "Comparison of Balanced Crystalloid Solutions: A Systematic Review and Meta-Analysis of Randomized Controlled Trials." Critical care explorations 3.5 (2021).
WIGGINS, WALTER S., et al. "The effect of salt loading and salt depletion on renal function and electrolyte excretion in man." Circulation 3.2 (1951): 275-281.
Hobensack, Michael. "Clinical Effects of Balanced Crystalloids vs Saline in Adults with Diabetic Ketoacidosis: Self WH, Evans CS, Jenkins CA, et al. JAMA Network Open. 2020; 3 (11): e2024596." Journal of Emergency Medicine 60.4 (2021): 578-579.
Lopes, Anselmo Dantas, Alexandre Toledo Maciel, and Marcelo Park. "Evolutive physicochemical characterization of diabetic ketoacidosis in adult patients admitted to the intensive care unit." Journal of critical care 26.3 (2011): 303-310.
Okuda, Y. U. K. I. C. H. I., et al. "Counterproductive effects of sodium bicarbonate in diabetic ketoacidosis." The Journal of Clinical Endocrinology & Metabolism 81.1 (1996): 314-320.
Wilcox, Christopher S. "Regulation of renal blood flow by plasma chloride." The Journal of clinical investigation 71.3 (1983): 726-735.
Chua, Horng-Ruey, et al. "Plasma-Lyte 148 vs 0.9% saline for fluid resuscitation in diabetic ketoacidosis." Journal of critical care 27.2 (2012): 138-145.
Self, Wesley H., et al. "Clinical effects of balanced crystalloids vs saline in adults with diabetic ketoacidosis: a subgroup analysis of cluster randomized clinical trials." JAMA network open 3.11 (2020): e2024596-e2024596.
Williams, Vijai, et al. "0.9% saline versus Plasma-Lyte as initial fluid in children with diabetic ketoacidosis (SPinK trial): a double-blind randomized controlled trial." Critical Care 24.1 (2020): 1-10.