532 - Effect of Caffeine on Diaphragmatic Excursion in Preterm Infants – preliminary results

Publication Number: 3513.532

Ayala Gover, Bnai-Zion Medical Center, Haifa, Hefa, Israel; Morya Shnaider, Bnai Zion Medical Center, Haifa, Hefa, Israel; Lilach Shkolnik Arad, Technion – Israel Institute of Technology, Haifa, HaZafon, Israel; Naama Tal-Shahar, Bnai Zion Medical Center, Haifa, HaZafon, Israel; Irit Shoris, Bnai Zion Medical Center, Haifa, HaZafon, Israel; Arieh Riskin, Bnai Zion Medical Center, Rappaport Faculty of Medicine, Technion, Israel institute of Technology, Haifa, Israel, Haifa, Hefa, Israel

Background: Caffeine is widely accepted and frequently used for apnea of prematurity in preterm infants. In addition to its central action on adenosine receptors it was also shown to directly affect diaphragmatic activity.
Ultrasound (US) serves as a point-of-care tool applied in assessing various aspects of lung function, including diaphragmatic movement. It has been shown before that diaphragmatic excursion increases after a single dose of caffeine in preterm infants, however longitudinal studies have not been conducted.

Objective: To assess the effect of caffeine on diaphragmatic excursion evaluated by ultrasound in preterm infants over time.

Design/Methods: Single center prospective observational study. Preterm infants born < 32 weeks of gestational age receiving caffeine treatment were recruited, and serial lung and diaphragmatic ultrasound studies were performed 15 minutes before and one hour after a maintenance caffeine dose on day 1-3, 7 and 14 of life. Exclusion criteria were mechanical ventilation, congenital anomalies and hemodynamic instability.

Results: Twenty infants were recruited, with a total of 50 ultrasound studies performed on stable infants with non-invasive respiratory support or in room air. Mean gestational age was 29.3± 1.9 and mean birth weight was 1224 g ±347. Thirty three (66%) of ultrasound studies were performed on infants receiving non-invasive respiratory support at the time of exam and 17 (34%) were performed in infants in room air. Diaphragmatic excursion increased after the administration of the caffeine dose in the first two ultrasounds but only a minimal change was observed on the third ultrasound (Table 1) but this did not reach statistical significance. The measured excursion before the caffeine dose on the third ultrasound reached similar values to post caffeine administration values in the previous exams. In multiple linear regression models, cumulative dose had some effect on the excursion difference, as well as current weight and need for respiratory support, although it did not reach statistical significance.

Conclusion(s): In this preliminary study the effect of caffeine on increasing diaphragmatic excursion decreased at 2 weeks of age compared to the first week of life, although this was not statistically significant. This finding may suggest some caffeine tolerance over time, or a decreased influence of caffeine on the diaphragm with maturation, weight gain and improved lung function reflected in lesser need of respiratory support.

Comparison of newborn characteristics and diaphragmatic excursion parameters before and after caffeine dose over time
*Mean ±SD **Median (IQR 25%,75%)

Diaphragmatic excursion before and after administration of caffeine dose
Mean diaphragmatic excursion is presented in mm


Diaphragmatic excursion measured by M-mode