PT - JOURNAL ARTICLE AU - Olie Chowdhury AU - Silke Lee AU - Simon Hannam AU - Gerrard F. Rafferty AU - Anne Greenough TI - Appropriate level of volume targeting for ventilated infants born at or near term DP - 2011 Sep 01 TA - European Respiratory Journal PG - 1919 VI - 38 IP - Suppl 55 4099 - http://erj.ersjournals.com/content/38/Suppl_55/1919.short 4100 - http://erj.ersjournals.com/content/38/Suppl_55/1919.full SO - Eur Respir J2011 Sep 01; 38 AB - Aims: To determine the most appropriate level of volume targeting (VT) for ventilated infants born at or near term.Methods: Study one: expiratory tidal volumes (VTe) were measured during time cycled, pressure limited ventilation either using a pneumotachograph or the ventilator's software; at least 80 breaths were analysed per infant. Study two: infants were studied at VT levels of 4, 5 and 6 mls/kg delivered in random order, with return to baseline between each VT level. The transdiaphragmatic pressure-time product (PTPdi), a measure of the work of breathing, was assessed at each VT level and during the baseline periods. To measure PTPdi, oesophageal and gastric pressures are measured and PTPdi calculated by integration of the transdiaphragmatic pressure signal with time for each breath and expressed per minute. In both studies, infants are only assessed when their blood gases are within the normal range.Results: To date: Study one: 20 infants, median gestational age of 39 (range 35-41) weeks, had a median VTe of 5 (range 1.4-9.7) mls/kg; 50% of infants had a VTe outside the “normal” tidal volume range (4 to 6mls/kg). Study two: the median PTPdi of 11 infants, median gestational age 39 (35-41) weeks, at a VT level of 4 mls/kg (310, IQR 244-332 cmH2O.s/min) was almost double that at 6 mls/kg (median 163, IQR 122-220 cmH2O.s/min), (p<0.001).Conclusion: During time cycled, pressure limited ventilation, infants born at or near term are frequently ventilated using volumes outside the “normal” tidal range. Yet, even within that range, low compared to high levels of volume targeting significantly increase the work of breathing.