Effect of maturation of the magnitude of mechanosensitive and chemosensitive reflexes in the premature human esophagus

Jadcherla, Sudarshan Rao; Hoffmann, Raymond G.; Shaker, Reza

doi:10.1016/j.jpeds.2006.02.041

« Previous Next »The Journal of Pediatrics
Volume 149, Issue 1 , Pages 77-82, July 2006

Effect of maturation of the magnitude of mechanosensitive and chemosensitive reflexes in the premature human esophagus

Sections of Neonatology and Pediatric Gastroenterology and Nutrition at the Columbus Children’s Hospital, Department of Pediatrics, the Ohio State University School of Medicine and Public Health, Columbus, Ohio; the Department of Biostatistics, Medical College of Wisconsin, Milwaukee, Wisconsin; and the Division of Gastroenterology and Hepatology, Department of Internal Medicine, and the Dysphagia Institute, Medical College of Wisconsin, Milwaukee, Wisconsin.

Received 26 May 2005; received in revised form 9 February 2006; accepted 20 February 2006.

Objectives

To investigate the effect of esophageal mechanosensitive and chemosensitive stimulation on the magnitude and recruitment of peristaltic reflexes and upper esophageal sphincter (UES)-contractile reflex in premature infants.

Study design

Esophageal manometry and provocation testing were performed in the same 18 neonates at 33 and 36 weeks postmenstrual age (PMA). Mechanoreceptor and chemoreceptor stimulation were performed using graded volumes of air, water, and apple juice (pH 3.7), respectively. The frequency and magnitude of the resulting esophago-deglutition response (EDR) or secondary peristalsis (SP), and esophago-UES-contractile reflex (EUCR) were quantified.

Results

Threshold volumes to evoke EDR, SP, or EUCR were similar. The recruitment and magnitude of SP and EUCR increased with volume increments of air and water in either study (P < .05). However, apple juice infusions resulted in increased recruitment of EDR in the 33 weeks group (P < .05), and SP in the 36 weeks group (P < .05). The magnitude of EUCR was also volume responsive (all media, P < .05), and significant differences between media were noted (P < .05). At maximal stimulation (1 mL, all media), sensory-motor characteristics of peristaltic and EUCR reflexes were different (P < .05) between media and groups.

Conclusions

Mechano- and chemosensitive stimuli evoke volume-dependent specific peristaltic and UES reflexes at 33 and 36 weeks PMA. The recruitment and magnitude of these reflexes are dependent on the physicochemical properties of the stimuli in healthy premature infants.

Abbreviations: EDR, Esphago-deglutition response , EUCR, Esophago-USE-contractile reflex , GEE, Generalized estimating equation , GER, G astroesophageal reflux , LES, Lower esophageal sphincter , PMA, Postmenstrual age , PP, Primary peristalsis , SP, Secondary peristalsis , UES, Upper esophageal sphincter , UESP, Upper esophageal sphincter pressure