In group 1, the intraoperative data points were obtained from a computerized query of the Microsoft SQL2003 database providing storage for data from Vanderbilt University's electronic anesthesiology documentation system, the Vanderbilt Perioperative Informatics Medical System (VPIMS)©. Data queried from the database included intraoperative pulse oximetry (SpO2) values (Nellcor pulse oximeters via a Philips Intellivue MP 90 monitor) and time correlated intraoperative partial pressure of oxygen (PaO2) determinations made by arterial blood sampling (Laboratory Gem Premier 3000, Instrumentation Technology) in all mechanically ventilated (MV) adults, undergoing general anesthesia. We excluded patients who were scheduled for cardiovascular surgeries, due to the potential effect of cardiopulmonary bypass and hypothermia on blood gas data, and those having thoracotomies with resultant lung resection or hypo-inflation for surgical purposes. In group 2, PaO2 and corresponding SpO2 values were obtained form the ARMA study database of patients with acute respiratory distress syndrome (ARDS).(8 (link))
In our discussions with experts in the field - both clinicians and researchers - the unmet need in this area was to develop an easy to use and reliable imputation for PF ratios by using SF threshold values, without having the clinicians and research personnel perform difficult calculations, incorporating the covariates that may have played a role in this relationship. Hence a decision was made first to develop a model without any covariates, enabling the calculation of the SOFA score when only SpO2 was available in a broad range of patients. To study the possible contribution of PEEP to the predictive value of SF and PF, we evaluated a second model to determine the relationship between SF and PF ratios within 3 categories of PEEP support: <8 centimeters of water (cm H2O), 8–12 cm H2O and > 12 cm H2O.
In our discussions with experts in the field - both clinicians and researchers - the unmet need in this area was to develop an easy to use and reliable imputation for PF ratios by using SF threshold values, without having the clinicians and research personnel perform difficult calculations, incorporating the covariates that may have played a role in this relationship. Hence a decision was made first to develop a model without any covariates, enabling the calculation of the SOFA score when only SpO2 was available in a broad range of patients. To study the possible contribution of PEEP to the predictive value of SF and PF, we evaluated a second model to determine the relationship between SF and PF ratios within 3 categories of PEEP support: <8 centimeters of water (cm H2O), 8–12 cm H2O and > 12 cm H2O.
