Ng S C, Quak S H
Department of Neonatology, Kandang Kerbau Women's and Children's Hospital, Singapore.
J Pediatr Gastroenterol Nutr. 1998 Oct;27(4):411-4. doi: 10.1097/00005176-199810000-00009.
Preterm infants are predisposed to gastroesophageal reflux, which may manifest itself in many ways ranging from failure to thrive to vomiting. Extended distal esophageal pH monitoring is the gold standard for diagnosing reflux in the preterm infants and it is our objective to establish extended distal esophageal pH norms (reference values) for well, asymptomatic preterm infants and to compare with norms already established for term infants, children, adolescents, and adults.
Twenty-one well, asymptomatic preterm infants consuming at least 70% of required maintenance oral feedings were recruited. The mean +/- standard deviation birth weight was 1549 +/- 439 g (range, 670-2470 g); the mean postconceptional age was 30.7 +/- 2.6 weeks (range, 25-35 weeks) and the mean postnatal age was 14 +/- 9 days (range, 2-40 days). Extended distal esophageal pH monitoring was performed on each of the infants, and the following parameters were calculated: reflux index, number of reflux episodes per day, number of reflux episodes lasting more than 5 minutes per day, and the longest recorded reflux episode.
The mean reflux index was 0.7 +/- 1.1%, the mean number of reflux episodes per day was 7.6 +/- 11.2, the mean number of reflux episodes lasting more than 5 minutes per day was 0.5 +/- 1.1 and the mean longest recorded reflux episode was 4.2 +/- 6.1 minutes. These results were comparable to those seen in term infants, children, adolescents, and adults. The trends for pH norms according to postconceptional age and postnatal age seemed to suggest that lower esophageal sphincter maturation might be related to postconceptional age, but the differences observed were not statistically significant (p > 0.05).
The norms (reference values) for well, asymptomatic preterm infants were comparable to those seen in term infants, children, adolescents, and adults. With the establishment of these norms, the search for a causal link between many of the respiratory problems encountered in prematurity and gastroesophageal reflux may be aided and the complications associated with gastroesophageal reflux may consequently be reduced.
早产儿易患胃食管反流，其表现形式多样，从生长发育迟缓到呕吐不等。延长的食管远端pH监测是诊断早产儿反流的金标准，我们的目标是为健康、无症状的早产儿建立延长的食管远端pH正常范围（参考值），并与已为足月儿、儿童、青少年和成人建立的正常范围进行比较。
招募了21名健康、无症状的早产儿，他们经口喂养量至少达到所需维持量的70%。平均出生体重±标准差为1549±439克（范围670 - 2470克）；平均孕龄为30.7±2.6周（范围25 - 35周），平均出生后年龄为14±9天（范围2 - 40天）。对每名婴儿进行延长的食管远端pH监测，并计算以下参数：反流指数、每日反流发作次数、每日持续超过5分钟的反流发作次数以及记录到的最长反流发作时间。
平均反流指数为0.7±1.1%，平均每日反流发作次数为7.6±11.2次，平均每日持续超过5分钟的反流发作次数为0.5±1.1次，记录到的最长反流发作平均时间为4.2±6.1分钟。这些结果与足月儿、儿童、青少年和成人的结果相当。根据孕龄和出生后年龄的pH正常范围趋势似乎表明，食管下括约肌成熟可能与孕龄有关，但观察到的差异无统计学意义（p>0.05）。
健康、无症状早产儿的正常范围（参考值）与足月儿、儿童、青少年和成人的相当。随着这些正常范围的建立，有助于寻找早产时遇到的许多呼吸问题与胃食管反流之间的因果联系，从而可能减少与胃食管反流相关的并发症。
