Effects of infusion rates of 7.2% sodium chloride + 6% dextran 70 solution on plasma osmolality and electrolyte concentrations in normovolemic sheep

SUMMARYSmall volume resuscitation used for the initial treatment of severehypovolemia and shock for the last two decades is expressed rapid infusion of smallvolumes 7.2-7.5% sodium chloride (NaCl) + colloid. 7.2% hypertonic NaCl + %6dextran 70 (HSD) causes rapid increase in plasma volume and maintain this effectfor longer periods. With this effect, HSD proves long term hemodynamic andmetabolic benefits in body. HSD is not only used in the treatment of hypovolemicshock, but also head trauma, burns, sepsis, multiple organ dysfunction syndrome andcardio-vascular surgery. The main disadvantages of HSD administrations arehypernatremia, demyelination, transient hyperchloremic acidosis, coagulopathy,acute renal insufficiency and anaphylaxia.In this study, the effects of infusion rates of HSD used for small volumeresuscitation on plasma electrolytes and osmolality in healthy sheep wasinvestigated.8 months of age, 14 healthy Chios-Merinos sheep were randomly separatedinto two groups (n=7). 4 ml/kg dose of 7.2% hypertonic NaCl and 6% dekstran 70(Macrodex, Eczacıbaşı) was administered in 2 minutes as a bolus infusion in the firstgroup and as a slow infusion in 20 minutes in the second group. Serum samples fromthe sheep were collected before and 0, 5, 10, 15, 30, 60, 90, 120, 180, 360. min afterthe fluid administration from the jugular vein to the anticoagulated (lithium heparin)sampling tubes. Significant (p<0.001) increases in plasma Na+, Cl- concentrationsand osmolality and significant (p<0.001) decreases in plasma K+ concentrations andHtc values has been determined in both groups after the fluid administration. Duringthe study period, no statistical difference in Na+ concentrations and Htc values hasbeen determined between groups however, significant differences has been seen atthe 0, 5 ve 10th min. on K+ concentration (p<0.05), at the 90 and 120th min on Cl-concentration (p<0.05) and from 60th min to the end of the study on osmolality (p<0.05)between groups.In conclusion, bolus and slow infusions of HSD have different effects on plasmaNa+, Cl-, K+ concentrations and osmolality and the infusion rate should be chosenevaluating the clinical indication.