Effect of hypertonic saline dextran on acid-base balance in patients undergoing surgery of abdominal aortic aneurysm.

Abstract

OBJECTIVE:

To evaluate the magnitude and cause of metabolic acidosis after infusion of 7.5% sodium chloride 6% dextran 70.

DESIGN:

Randomized, prospective clinical study.

SETTING:

University hospital.

PATIENTS:

Two groups of 14 patients each, undergoing repair of abdominal aortic aneurysm.

INTERVENTIONS:

Patients were randomly assigned to receive either 250 mL of hypertonic saline dextran (HSD) or a conventional fluid regimen with 250 mL of hydroxyethyl starch in normal saline solution (H-NS) during the period of aortic clamping. Additionally, normal saline was used in both groups to reach a target pulmonary artery occlusion pressure of 15-18 mmHg. pH, Paco2, and serum concentrations of sodium, potassium, magnesium, calcium, chloride, lactate, albumin, and phosphate were measured. Strong ion difference was calculated as (sodium + potassium + magnesium + calcium) - (chloride + lactate). The amount of weak plasma acid was calculated.

MEASUREMENTS AND MAIN RESULTS:

The infusion of HSD resulted in an immediate large increase in serum sodium (19 mmol/L) and chloride (22 mmol/L), whereas the infusion of H-NS led only to mild increases in serum sodium (3 mmol/L) and chloride (6 mmol/L). Both HSD and H-NS caused concomitant and equal decreases in the amount of weak plasma acid, strong ion difference, and pH (7.28-7.30). The reduction of bicarbonate was also identical and proportional to the extent of dilution due to infusion of HSD and H-NS. This induced metabolic acidosis was corrected spontaneously in both groups 24 hrs after surgery.

CONCLUSION:

Both the intravenous administration of 7.5% sodium chloride and the conventional fluid regimen with saline-based 6% hydroxyethyl starch solution resulted in a metabolic acidosis of equal extent. This suggests dilution of plasma buffers or a decrease in strong ion difference to be the primary cause of metabolic acidosis.

• Authors: Dirk Bruegger, Andreas Bauer, Markus Rehm, Markus Niklas, Matthias Jacob, Michael Irlbeck, Bernhard F Becker, Frank Christ
• Journal: Critical care medicine (Crit Care Med) Vol. 33 Issue 3 Pg. 556-63 (Mar 2005) ISSN: 0090-3493 [Print] United States
• PMID: 15753747 (Publication Type: Clinical Trial, Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Dextrans
• Saline Solution, Hypertonic
• hypertonic saline-dextran solution
• Sodium Chloride

Topics

• Acid-Base Equilibrium (drug effects)
• Acidosis (etiology)
• Aged
• Analysis of Variance
• Aortic Aneurysm, Abdominal (surgery)
• Dextrans (adverse effects, pharmacology, therapeutic use)
• Female
• Fluid Therapy (adverse effects, methods)
• Humans
• Male
• Perioperative Care
• Prospective Studies
• Saline Solution, Hypertonic (adverse effects, pharmacology, therapeutic use)
• Sodium Chloride (adverse effects, pharmacology, therapeutic use)