A Randomized Clinical Trial Comparing the Effect of Rapidly Infused Crystalloids on Acid-Base Status in Dehydrated Patients in the Emergency Department

Abstract

Study objective: To compare the effect of normal saline (NS), lactated Ringer's, and Plasmalyte on the acid-base status of dehydrated patients in the emergency department (ED).Method: We conducted a prospective, double-blind, randomized trial of consecutive adult patients who presented to the emergency department with moderate-severe dehydration. Patients were randomly allocated to blindly receive normal saline (NS), lactated Ringer's or Plasmalyte at 20 ml/kg/h for 2 hours. Outcome measures of the study were pH and changes in electrolytes, including serum potassium, sodium, chloride and bicarbonate levels at 0, 60, and 120 minutes in venous blood gas samples.Results: Ninety patients participated in the study and were randomized to NS (30 patients), lactated Ringer's (30 patients) and Plasmalyte (30 patients) groups. Mean age was 48±20 years and 50% (n=45) of the patients were female. All pH values were in the physiological range (7.35-7.45) throughout the study period. In the NS group there was a significant tendency to lower pH values, with pH values of 7.40, 7.37, and 7.36 at 0, 1, and 2 hours respectively. Average bicarbonate levels fell in the NS group (23.1, 22.2, and 21.5 mM/L) and increased in the Plasmalyte group (23.4, 23.9, and 24.4 mM/L) at 0, 1, and 2 hours, respectively. There were no significant changes in potassium, sodium, or chloride levels.Conclusions: NS, lactated Ringer's, and Plasmalyte have no significant effect on acid-base status and all can be used safely to treat dehydrated patients in the emergency department. However, NS can effect acidosis which might be significant in patients who have underlying metabolic disturbances; thus, its use should be weighed before fluid administration in the ED.

Impact of common crystalloid solutions on resuscitation markers following Class I hemorrhage

“…Their study found that base deficit became more positive, pH was higher, and Cl was lower in the group of patients randomized to receive Plasma-Lyte A when compared with the NS arm. 35 A similar study by Hasman et al 36 randomized emergency department patients with dehydration to receive NS, LR, or Plasma-Lyte A for rehydration and measured baseline, 60-, and 120-minute postinfusion blood gases and chemistries. They found that Na and Cl remained static regardless of the fluid, while pH and bicarbonate significantly decreased in the NS group over time and compared with the other IV fluids.…”

Crystalloids and colloids in critical patient resuscitation

“…The authors did not find any of these solutions to significantly alter the acid-base equilibrium, though there was a tendency toward lower pH values in the group that received saline solution. 43 In severely polytraumatized patients, resuscitation with a balanced solution resulted in a lesser incidence of hyperchloremic acidosis than with saline solution. There was no impact in terms of the incidence of renal dysfunction, resource utilization or mortality---though this study was not designed to detect differences in mortality.…”

Cristaloides y coloides en la reanimación del paciente crítico

“…Los autores no encontraron que ninguna de estas soluciones alterara significativamente el equilibrio ácido-base, si bien existía una tendencia a un menor valor del pH en el grupo que recibió suero salino 43 . En pacientes con politraumatismo grave, la reanimación con una solución balanceada ocasionó una menor incidencia de acidosis hiperclorémica que la solución salina, aunque sin impacto en la tasa de disfunción renal, utilización de recursos o mortalidad, aunque este estudio no estaba diseñado para hallar diferencias en mortalidad 44 .…”