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DOI: http://dx.doi.org/10.21088/ijaa.2349.8471.5318.1

Abstract

Background: The most commonly used isoosmolar fluid in neurosurgery is 0.9% saline, which is known to produce hyperchloraemic metabolic acidosis. A balanced salt solution, like PlasmaLyte A, is not only isoosmolar, but also maintains acid –base balance and is stated to produce less serum chloride changes. Our aim was to study the effects of PlasmaLyte-A on acid base balance, serum osmolarity and serum electrolytes in neurosurgical procedures. Methodology: 70 patients posted for elective supratentorial craniotomies were randomly allocated to two groups, to receive either 0.9% saline or PlasmaLyte A as the sole intravenous fluid. Arterial Blood Gas Samples were analysed at regular intervals and the variables noted were: serum osmolarity, pH, base deficit or excess, serum chloride, serum lactate, serum sodium, serum potassium, serum calcium, and glucose levels. Intergroup data was analysed statistically by student’s T test (continuous) and chi-square test (categorical) while repeated ANNOVA and post-hoc Tukey Kramer test was used to analyze data within each group using NCSS statistical software version 9.0. Results: Towards the end of the surgery, pH was found to be low in the normal saline group (7.334±0.05 and 7.275±0.05) as compared to the plasmalyte group (7.402±0.03 and 7.406±0.03), this difference being statistically highly significant (p<0.0001). The difference in base deficit was also highly significant at the same time intervals. Chloride levels were significantly higher in the normal saline group in comparison to the study group at different time intervals (112.8±8.002 and 103.63±6.17) and (115.77±9.84 and 103.15±2.95) (p value<0.0001) while serum electrolytes and serum osmolarity was found to be comparable in both the groups. Conclusion: We conclude that 0.9% saline when used as sole intravenous fluid in neurosurgical procedures, causes significantly higher chloride levels and significant acidosis when compared to plasmalyte A used for the same purpose.

 

 

Keywords : Neurosurgery; Craniotomy; Acid-Base Equilibrium; Osmolarity; Electrolytes; Fluid Therapy. 

Corresponding Author : Narmada Padhy, Associate Professor, Neuroanaesthesiology Section, Department of Anaesthesiology and Intensive Care, Nizam’s Institute of Medical Sciences, Hyderabad, Telangana 500082 India.