@article {UngerPA1596, author = {Stefan Unger and Christopher Halliday and Steve Cunningham}, title = {Blood gas analysis in acute bronchiolitis {\textendash} Who and when?}, volume = {48}, number = {suppl 60}, elocation-id = {PA1596}, year = {2016}, doi = {10.1183/13993003.congress-2016.PA1596}, publisher = {European Respiratory Society}, abstract = {Utilisation of blood gas analysis(BGA) in acute bronchiolitis is common but evidence for current guidelines is sparse. This study investigated indicators demarcating clinically important rise in carbon dioxide(CO2).A prospective observational study assessed children admitted from an emergency department(ED) to a tertiary care hospital with bronchiolitis (10/14{\textendash}01/15). Hospital charts and electronic patient data were analysed using logistic regression models to examine relationships between rise in CO2 and possible clinical indicators.220 patients with bronchiolitis were admitted (mean age 0.57years (95\%CI:0.05,0.64)). 113(51\%) had at least one BGA. 14\% required high dependency care(HDU). In ED CO2\>7kPA was associated with HDU admission (OR 3.75(95\%CI:1.13,12.47),p=0.031); prematurity and young age also independently predicted HDU (IRR 1.53(95\%CI:1.21,1.93),p\<0.0001 and IRR 0.68(95\%CI:0.53,0.86),p=0.001 respectively). All but one patient with CO2\>7kPa in ED were\<3months and/or premature. Length of stay(LOS) was also significantly longer in this patient group. For BGA taken during the admission, only oxygen requirement and young age were significantly associated with CO2\>7kPa (OR 2.46(95\%CI:1.42,4.26),p=0.001 and OR 0.08(95\%CI:0.03,0.17),p\<0.001; respectively). There was no association between oxygen quantity supplemented and level of CO2. Overall, LOS was significantly higher in those who had BGA during admission (4.0days (d) (95\%CI 3.5,4.5) versus 2.3d (95\%CI:2.0,2.6)).Age under 3m, history of prematurity and CO2\>7kPa in ED identify those with prolonged LOS and/or HDU admission. Significantly raised CO2 is not seen without oxygen requirement. Further work aims to elucidate when BGA may be helpful in bronchiolitis.}, issn = {0903-1936}, URL = {https://erj.ersjournals.com/content/48/suppl_60/PA1596}, eprint = {https://erj.ersjournals.com/content}, journal = {European Respiratory Journal} }