A pilot study evaluating predictors of postoperative outcomes after major abdominal surgery: physiological capacity compared with the ASA physical status classification system

Abstract

BackgroundThis pilot study compared the risk predictive value of preoperative physiological capacity (PC: defined by gas exchange measured during cardiopulmonary exercise testing) with the ASA physical status classification in the same patients (n=32) undergoing major abdominal cancer surgery.MethodsUni- and multivariate logistic regression models were fitted to measurements of PC and ASA rank data determining their predictive value for postoperative morbidity. Receiver operating characteristic (ROC) curves were used to discriminate between the predictive abilities, exploring trade-offs between sensitivity and specificity.ResultsIndividual statistically significant predictors of postoperative morbidity included the ASA rank [P=0.038, area under the curve (AUC)=0.688, sensitivity=0.630, specificity=0.750] and three newly identified measures of PC: PAT (% predicted anaerobic threshold achieved, <75% vs ≥75%), ΔHR1 (heart rate response from rest to the anaerobic threshold), and HR3 (heart rate at the anaerobic threshold). A two-variable model of PC measurements (ΔHR1+PAT) was also shown to be statistically significant in the prediction of postoperative morbidity (P=0.023, AUC=0.826, sensitivity=0.813, specificity=0.688).ConclusionsThree newly identified PC measures and the ASA rank were significantly associated with postoperative morbidity; none showed a statistically greater association compared with the others. PC appeared to improve predictive sensitivity. The potential for new unidentified measures of PC to predict postoperative outcomes remains unexplored.

Building the Neglected Anesthetic Practice in Post-War Afghanistan: An Experience of a Decade of Rehabilitation

“…Although abnormalities were recorded in ASA I and II, which was 13.8% in our study, they have been reported to be much higher in few other studies (6).…”

Cardiopulmonary exercise testing for the evaluation of perioperative risk in non-cardiopulmonary surgery

“…However, data that are available indicate that CPET variables outperform methods that estimate functional capacity such as the VSAQ,8 markers of resting cardiac and respiratory function,17 18 and risk indices such as the ASA16 and the RCRI 8 9. For mixed intra-abdominal surgery, the ability of AT to predict all cause mortality (AUC 0.68)9 was higher than that reported for the RCRI in a recent systematic review (AUC 0.62) 23…”

“…A particular strength of the studies by Snowden and Hightower is that clinicians were blinded to the CPET results, ensuring they did not influence patient care or data collection 8 16. This should give a more accurate reflection of the true magnitude of the association between CPET variables and outcome by removing the effect of confounding due to clinicians acting on CPET variables and influencing outcome (eg, choice of level of postoperative care received by the patient) 22…”

Morbidity in elderly women undergoing gynaecological pelvic floor surgery

“…In our investigation, there were no significant differences in duration of the surgical procedure between study and control group, and none individual of either group received blood transfusions. The ASA classification on the one hand can be used for individual estimation for the peri-and postoperative risk factors, and on the other hand it correlates with short and long time survival of the patients [27,32]. We could demonstrate that there were no significant differences concerning the ASA status.…”