Intraoperative end-tidal carbon dioxide and postoperative mortality in major abdominal surgery: a historical cohort study

Preoperative forced expiratory volume in one second and postoperative respiratory outcomes in nonpulmonary and noncardiac surgery: a retrospective cohort study

BACKGROUND

Although the usefulness of pulmonary function tests has been established for lung resection and coronary artery bypass surgeries, the association between preoperative pulmonary function test and postoperative respiratory complications in nonpulmonary and noncardiac surgery is inconclusive. The purpose of this study was to determine the association between preoperative forced expiratory volume in one second (FEV1) on pulmonary function test and the development of postoperative respiratory failure and/or death in patients undergoing major nonpulmonary and noncardiac surgery.

METHODS

Adult patients aged ≥ 18 years and who underwent nonpulmonary and noncardiac surgery with expected moderate to high risk of perioperative complications from June 2012 to March 2019 were included. The primary exposure was preoperative FEV1 measured by pulmonary function test within six months before surgery. The primary outcome was respiratory failure (i.e., invasive positive pressure ventilation for at least 24 h after surgery or reintubation) and/or death within 30 days after surgery. A logistic regression model was used to adjust for the respiratory failure risk index, which is a scoring system that predicts the probability of postoperative respiratory failure based on patient and surgical factors, and to examine the association between preoperative FEV1 and the development of postoperative respiratory failure and/or death.

RESULTS

Respiratory failure and/or death occurred within 30 days after surgery in 52 (0.9%) of 5562 participants. The incidence of respiratory failure and/or death in patients with FEV1 ≥ 80%, 70%- < 80%, 60%- < 70%, and < 60% was 0.9%, 0.6%, 1.7%, and 1.2%, respectively. Multivariable logistic regression analysis showed no significant association between preoperative FEV1 and postoperative respiratory failure and/or death (adjusted odds ratio per 10% decrease in FEV1: 1.01, 95% confidence interval: 0.88-1.17, P = 0.838). Addition of FEV1 information to the respiratory failure risk index did not improve the prediction of respiratory failure and/or death [area under the receiver operating characteristics curve: 0.78 (95% confidence interval: 0.72-0.84) and 0.78 (95% confidence interval: 0.72-0.84), respectively; P = 0.84].

CONCLUSION

We found no association between preoperative FEV1 and postoperative respiratory failure and/or death in patients undergoing major nonpulmonary and noncardiac surgery.

Postoperative pulmonary complications and mortality after major abdominal surgery. An observational multicenter prospective study

BACKGROUND

Postoperative pulmonary complications (PPCs) significantly contribute to postoperative morbidity and mortality. We conducted a study to determine the incidence of PPCs after major elective abdominal surgery and their association with early and 1-year mortality in patient without pre-existing respiratory disease.

METHODS

We conducted a multicenter observational prospective clinical study in 40 Italian centers. 1542 patients undergoing elective major abdominal surgery were recruited in a time period of 14 days and clinically managed according to local protocol. The primary outcome was to determine the incidence of PPCs. Further, we aimed to identify independent predictors for PPCs and examine the association between PPCs and mortality.

RESULTS

PPCs occurred in 12.6% (95% CI 11.1-14.4%) of patients with significant differences among general (18.3%, 95% CI 15.7-21.0%), gynecological (3.7%, 95% CI 2.1-6.0%) and urological surgery (9.0%, 95% CI 6.0-12.8%). PPCs development was associated with known pre- and intraoperative risk factors. Patients who developed PPCs had longer length of hospital stay, higher risk of 30-days hospital readmission, and increased in-hospital and one-year mortality (OR 3.078, 95% CI 1.825-5.191; P<0.001).

CONCLUSIONS

The incidence of PPCs in patients without pre-existing respiratory disease undergoing elective abdominal surgery is high and associated with worse clinical outcome at one year after surgery. General surgery is associated with higher incidence of PPCs and mortality compared to gynecological and urological surgery.