Effect of 0.9% saline and Ringer’s lactate on mean change in blood glucose levels under spinal anaesthesia among diabetic patients

Context: It is common practice to avoid lactate-containing intravenous fluids in diabetic patients as it was hypothesized to cause hyperglycaemia by the conversion of lactate to glucose by hepatic gluconeogenesis. However, absence of sound theoretical basis, conflicting reports from numerous clinical trials and improved understanding of biochemistry have necessitated a closer scrutiny of this hypothesis.

Aims: The present study aims to determine the effect of 0.9% saline and Ringer’s lactate on blood glucose levels in the fasting diabetic surgical patients receiving spinal anaesthesia.

Settings and design: The study is a prospective randomized trial conducted on adult patients aged 30 – 85 years with well-controlled type 2 diabetes mellitus receiving spinal anaesthesia.

Methods and material: 120 patients with well-controlled type 2 diabetes mellitus receiving spinal anaesthesia were randomized to receive either 1 litre of 0.9% saline or Ringer’s lactate. Blood glucose levels were recorded using a glucometer by the pinprick method before and after infusion of 1 litre of the selected intravenous fluid.

Statistical analysis: Data analysis was done using SPSS statistical package - Version 22.0. Student’s unpaired ‘t’ test was used to test the significance of difference between quantitative variables. A 'p' value less than 0.05 was taken to denote statistical significance.

Results: Mean change in blood glucose levels after infusion of the intravenous fluid in 0.9% saline and Ringer’s lactate groups were 3.68±15.2 mg/dl and - 0.15±16.5 mg/dl, respectively. The difference between the two groups was not statistically significant with a 'p' value of 0.188.

Conclusions: Ringer’s lactate solution, when compared to 0.9% saline, does not cause significant change in the mean blood glucose levels in fasting diabetic patients receiving spinal anaesthesia.