@article { , title = {Do simple ventilation and gas exchange measurements predict early successful weaning from respiratory support in unselected general intensive care patients?}, abstract = {Background. The value of respiratory variables as weaning predictors in the intensive care unit (ICU) is controversial. We evaluated the ability of tidal volume (Vtexp), respiratory rate ( f ), minute volume (MVexp), rapid shallow breathing index ( f/Vt), inspired–expired oxygen concentration difference [(I–E)O2], and end-tidal carbon dioxide concentration (PE′CO2) at the end of a weaning trial to predict early weaning outcomes. Methods. Seventy-three patients who required .24 h of mechanical ventilation were studied. A controlled pressure support weaning trial was undertaken until 5 cm H2O continuous positive airway pressure or predefined criteria were reached. The ability of data from the last 5 min of the trial to predict whether a predefined endpoint indicating discontinuation of ventilator support within the next 24 h was evaluated. Results. Pre-test probability for achieving the outcome was 44\% in the cohort (n¼32). Non-achievers were older, had higher APACHE II and organ failure scores before the trial, and higher baseline arterial H+ concentrations. The Vt, MV, f, and f/Vt had no predictive power using a range of cut-off values or from receiver operating characteristic (ROC) analysis. The [I–E]O2 and PE′CO2 had weak discriminatory power [areaunder the ROC curve: [I–E]O2 0.64 (P¼0.03); PE′CO2 0.63 (P¼0.05)]. Using best cut-off values for [I–E]O2 of 5.6\% and PE′CO2 of 5.1 kPa, positive and negative likelihood ratios were 2 and 0.5, respectively, which only changed the pre- to post-test probability by about 20\%. Conclusions. In unselected ICU patients, respiratory variables predict early weaning from mechanical ventilation poorly.}, doi = {10.1093/bja/aeq184}, eissn = {1471-6771}, issn = {0007-0912}, note = {School: sch\_nur}, pages = {326-333}, publicationstatus = {Published}, publisher = {Oxford University Press}, url = {http://researchrepository.napier.ac.uk/id/eprint/10393}, volume = {105}, keyword = {610.73 Nursing, 616.2 Respiratory diseases, RT Nursing, Blood gas analysis, capnography, continuous positive airway pressure, mechanical ventilation, positive pressure ventilation, PEEP, pulmonary gas exchange, ventilator weaning;}, year = {2010}, author = {Monaco, F and Drummond, G B and Ramsay, Pamela and Servillo, G and Walsh, Timothy S} }