The effects of balanced versus saline based colloid and crystalloid solutions on acid-base and electrolyte balance in gastrointestinal surgery
Abstract
Background and Objectives: Large-volume administration of 0.9% saline are known to causes hyperchloremic metabolic acidosis (HMA) due to its high chloride load. Balanced or physiological fluids with inorganic ions are not associated with the same disturbance.
The purpose of this study was to see whether balanced crystalloid and colloid solutions cause less disturbances in postoperative acid base status than sodium chloride based solutions in patients undergoing elective open gastrointestinal surgery.
Methodology: Study subjects were patients aged between 30-60 years, ASA grades I and II, undergoing elective open gastrointestinal surgery, were selected as per proposed sampling design and were allotted into two groups, by the help of simple randomization process. Patients in the Group B received Hartmann’s solution and 6% hetastarch in balanced electrolyte and glucose solution and patients in the Group N received 0.9% sodium chloride solution and 6% hetastarch in 0.9% sodium chloride solution. Arterial blood samples were taken from both the groups of patients just prior to and 30 min after surgery. Baseline and final acid base status, heart rate, mean blood pressure, peripheral temperature, as well as urine output before, during and after surgery were recorded up to 48 hours. Prevalence of development of HMA was determined by appropriate statistical technique.
Results: The mean chloride level of normal saline group postoperatively was 118.66 ± 5.75 mmol/L (Normal range: 98-106 mmol/L) whereas in balanced saline group it was 103.27 ± 2.29 mmol/L, arterial pH was 7.31 ± 0.29 and 7.4 ± 0.02 respectively. Hence the changes in chloride level as well as arterial pH were significant in normal saline group versus balanced fluid group.
Conclusion: Normal saline based fluids cause significant alteration in arterial chloride and pH levels against the use of balanced fluids in gastrointestinal surgery.
