Acid base and electrolyte balance behavior in pediatric patients with blood priming.

Abstract

Objective: describe the behavior of the basic acid and electrolyte blood balance in pediatric patients with blood priming in extracorporeal circulation.

Methods: retrospective descriptive study, used a sample of 20 pediatric patients who were classified into subgroups according to ASC (Q1: 0.19-0.28 m2, Q2: 0.29-0.39 m2, Q3: 0.40-0.53 m2 and Q4: 0.54-1.21 m2) in the that cardiac surgery was performed with blood perfusion of the extracorporeal circuit. Variables were measured: pH, pCO2, hematocrit, potassium, calcium, bicarbonate, and excess base; in the red blood cells with which the circuit was purged, the blood gases: basal, at minute one and minute five of the perfusion. Data were analyzed according to body surface area in order to look for differences in the subgroups.

Results: the group of red blood cells exhibited an important basic acid and electrolyte imbalance: pH 6.90 (de: 0.07), pCO2 130.18mmHg (de: 19.60), potassium 9.79mEq/L (de: 5.62), calcium 0.20mEq/L (0.006) and excess base -18.89mEq/L (de: 6.57). Group one showed a slight base acid and electrolyte imbalance: pH 7.30 (from: 0.05), calcium 0.88mEq/L (from: 0.21), bicarbonate 19.07mEq/L (from: 2.63) and excess base -6.57 (from: 3.18); which after five minutes of perfusion (group minute five) reached a normal basic acid and electrolyte blood balance; but a slight acidosis persisted (7.33, from: 0.05).

Patients with higher body surface area (> 0.53m2) presented adequate basic acid and electrolyte blood balance at five minutes, while those with lower body surface area (<0.53m2) showed electrolytic compensation, but not base acid at five minutes of perfusion.

Conclusions: the basic acid and electrolyte imbalance in the blood, the effect of the blood priming in pediatric patients who enter the extracorporeal circulation, could be regulated by intrinsic compensatory systems five minutes after the infusion, which could be evidenced in this analysis. However, this could be due to multiple theoretical factors such as priming with a multi-electrolyte solution and an adequate pre-perfusion pathophysiological state.

There are cases in which it is probably required to add some medicine early to mediate the compensation of basic and electrolytic acid, due to emergent situations or other contributing factors, for which other types of studies can be obtained comparing variables studied versus administration of bicarbonate of priming sodium, implementation of the pre-perfusion ultrafiltration technique and perfusion initiation, before and after administering the cardioplegic solution.

The body surface area of ​​pediatric patients could be an independent variable in the behavior of this referred basic acid and electrolytic compensation.