RESUMEN
Disorders in fluid and electrolyte balance are among the most commonly encountered problems in the care of preterm infants especially with RDS. The aim of this study is to assess the most important serum electrolytes [Na, K and Cl] in preterm infants with RDS, on intravenous fluids, during the first 48 hours of age. Thirty preterm infants with RDS on intravenous fluid therapy were included in this study. They were classified into 4 groups: group 1 [NBW] included 5 preterms, group 2 [LBW] included 16 preterms, group 3 [VLBW] included 5 preterms and group 4 [ELBW] included 4 preterms. All of them were subjected to full history perinatal taking, thorough clinical examination and lab investigations including serum electrolytes [serum Na, K and Cl] on admission [initial sample] and after 48 hours [follow-up sample]. The results of the study revealed that hyponatremia was more prevalent in the initial sample [50-80%] than the follow-up sample [37-60%] in all studied groups, and the percentage persisted as much as 50% in ELBW in both samples. Hyperkalemia was also present with high percentage in the initial and the follow-up samples [20-60%] in all studied groups. Hypochloremia appeared in NBW and VLBW infants in the initial sample [20% and 40% respectively], while in the F.U. sample decreased to 20% in VLBW and disappeared in NBW infants. In LBW group, there was a statistically significant increase in serum sodium in F.U. sample compared to the initial sample [P < 0.05], while there was no significant difference between serum sodium levels in both samples in the other studied groups [P > 0.05]. No significant difference was found between the initial sample and F.U. sample regarding serum potassium and chloride levels in all studied groups [P > 0.05]. In conclusion, each of prematurity and RDS by itself enhance the occurrence of electrolyte abnormalities due to many factors. So, serial F.U. measurement of S.E. since delivery till establishment of adequate oral feeding helps in early detection of S.E. abnormalities and adjustment of IVF therapy