Tachygastria in Preterm Infants: A Longitudinal Cohort Study

OBJECTIVES

Tachygastria is a gastric dysrhythmia (>4 to ≤9 cycles per minute, cpm) associated with gastric hypomotility and gastrointestinal disorders. Healthy preterm infants spend more time in tachygastria than adults; however, normative values are not defined. We sought to determine the percent of time preterm infants spend in tachygastria.

METHODS

We conducted a longitudinal, prospective cohort study with weekly electrogastrography (EGG) recordings in 51 preterm <34 weeks' gestation and 5 term (reference) infants. We calculated percentage recording time in tachygastria (% tachygastria) and determined the mean ± standard deviation (SD) across EGG sessions. Mixed effects model was performed to test weekly variance in % tachygastria and gestational age effect. Successive pre- and post-prandial measurements were obtained to assess reproducibility of % tachygastria. We compared time to achieve full feeds between subjects with % tachygastria within 1 SD from the mean versus % tachygastria >1 SD from mean.

RESULTS

Three hundred seventy-six EGG sessions were completed (N = 56). Mean % tachygastria was 40% with SD ±5%. We demonstrated no change in % tachygastria across 9 postnatal weeks (P = 0.70) and no gestational age effect. No difference was demonstrated between successive pre- (P = 0.91) and post-prandial (P = 0.96) % tachygastria. Infants with 35%-45% tachygastria (within 1 SD from mean) had higher gestational age and less time to achieve full feeds than infants with <35% or >45% tachygastria.

CONCLUSIONS

EGG is a reproducible tool to assess % tachygastria in preterm infants. Clinical significance of increased or decreased % tachygastria needs further investigation to validate if 35%-45% tachygastria is safe for feeding.

Method for detection of microorganisms that produce gaseous nitrogen oxides

A method was developed to detect NO- or N(2)O-producing bacteria in solid or liquid medium by their ability to oxidize the redox indicator resazurin from its reduced colorless form to its oxidized pink form. The method was sensitive to as little as 35 nM N(2)O or 0.5 nM NO. Ninety-one percent of the colonies that oxidized resazurin on plates also produced N(2)O in slant cultures. Forty-four percent of the colonies that did not oxidize resazurin did produce N(2)O. This percentage was reduced to 15% when colonies in which the coloration was difficult to discern were picked to slants to determine whether they oxidized the slant. The production of N(2)O preceded the oxidation of resazurin by liquid cultures of Escherichia coli and a sludge isolate. With the denitrifying sewage isolate, the disappearance of N(2)O was followed by the return of resazurin to its reduced state. Wolinella succinogenes was found to produce small amounts of N(2)O from NO(3), which resulted in a transient oxidation of resazurin.