Emma E Williams1,2, Katie A Hunt1,2, Janathan Jeyakara3, Raghavendra Subba-Rao4, Theodore Dassios1,4, Anne Greenough5,6,7. 1. Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK. 2. The Asthma UK Centre for Allergic Mechanisms in Asthma, King's College London, London, UK. 3. Department of Physiology, School of Bioscience Education, Faculty of Life Sciences and Medicine, King's College London, London, UK. 4. Neonatal Intensive Care Unit, King's College Hospital NHS Foundation Trust, London, UK. 5. Department of Women and Children's Health, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK. anne.greenough@kcl.ac.uk. 6. The Asthma UK Centre for Allergic Mechanisms in Asthma, King's College London, London, UK. anne.greenough@kcl.ac.uk. 7. NIHR Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London, London, UK. anne.greenough@kcl.ac.uk.
Abstract
BACKGROUND: Administration of caffeine citrate can facilitate extubation. Our aim was to determine whether a loading dose of caffeine citrate given to ventilated, preterm infants affected the diaphragm electrical activity. METHODS: Infants <34 weeks of gestational age were recruited if requiring mechanical ventilation and prescribed a loading dose of caffeine citrate. Surface electrodes recorded the electrical activity of the diaphragm (dEMG) before and after administration of intravenous caffeine citrate. The mean amplitude of the EMG (dEMG) trace and the mean area under the EMG curve (aEMGc) were calculated. RESULTS: Thirty-two infants were assessed with a median gestational age of 29 (27-31) weeks. The dEMG amplitude increased, peaking at 25 min post administration (p = 0.006), and the increase in aEMGc (p = 0.004) peaked at 30 min; the differences were not significant after 60 min. At 20 min, there was an increase in minute volume (p = 0.034) and a reduction in the peak inspiratory pressure (p = 0.049). CONCLUSIONS: We have demonstrated a transient increase in both electrical activity of the diaphragm and respiratory function following an intravenous loading dose of caffeine citrate.
BACKGROUND: Administration of caffeine citrate can facilitate extubation. Our aim was to determine whether a loading dose of caffeine citrate given to ventilated, preterm infants affected the diaphragm electrical activity. METHODS:Infants <34 weeks of gestational age were recruited if requiring mechanical ventilation and prescribed a loading dose of caffeine citrate. Surface electrodes recorded the electrical activity of the diaphragm (dEMG) before and after administration of intravenous caffeine citrate. The mean amplitude of the EMG (dEMG) trace and the mean area under the EMG curve (aEMGc) were calculated. RESULTS: Thirty-two infants were assessed with a median gestational age of 29 (27-31) weeks. The dEMG amplitude increased, peaking at 25 min post administration (p = 0.006), and the increase in aEMGc (p = 0.004) peaked at 30 min; the differences were not significant after 60 min. At 20 min, there was an increase in minute volume (p = 0.034) and a reduction in the peak inspiratory pressure (p = 0.049). CONCLUSIONS: We have demonstrated a transient increase in both electrical activity of the diaphragm and respiratory function following an intravenous loading dose of caffeine citrate.