Time-wise sequential analysis of gastric aspirate for occult blood and pH in sick preterm infants.

Improvements in both care and technology have led to the survival of more low birthweight infants. Initially, these infants are not fed orally and are placed on parenteral nutrition. In an attempt to evaluate sequential time-wise changes in gastric pH and occult blood loss, evaluation of gastric pH and tests for the presence of blood in the gastric aspirate were carried out in two groups of infants. Group 1 consisted of seven cases, three males and four females, with a mean +/- SE gestation of 29.9 +/- 0.8 weeks and a birthweight of 1410 +/- 190 g. Group 2 consisted of nine cases, three males and six females, with a mean +/- gestation of 28.6 +/- 0.84 weeks and a birthweight of 940 +/- 120 g. Gastric contents were sampled through indwelling orogastric tubes every 4-6 h daily for the first seven days in Group 1 and 14 days in Group 2. Infants in Group 1 were spontaneously breathing with mild hyaline membrane disease (HMD) whereas Group 2 infants had severe HMD requiring ventilation. Results indicate that critically ill preterm infants (Group 2) had significantly lower pH when compared to Group 1 (p less than 0.015). Progressive decrease in pH was observed in both groups (P less than 0.001). The association of occult gastric blood loss with decreasing pH was examined using pooled data from both groups of neonates. During the times when bleeding occurred, the mean +/- SE gastric pH level was 2 +/- 0.1.(ABSTRACT TRUNCATED AT 250 WORDS)