Last updated on July 2019

Postoperative Pulmonary Complications in Major Abdominal Surgery

Brief description of study

The purpose of this study is to determine the incidence of pulmonary complications in patients undergone major abdominal elective surgery performed under general anesthesia.

Detailed Study Description


The primary aim of the study is to evaluate the incidence and characteristics of postoperative pulmonary complications (PPC) in patients undergoing major abdominal surgery.


The secondary aim of the study is to define the incidence of postoperative infections, cardiovascular complications, postoperative residual curarization (PORC), duration of ventilatory support, need of re-intubation, need of ICU admission and ICU length of stay, total length of hospitalization, mortality during hospitalization and postoperative outcome (assessed at 30, 60 days and 1 year after hospital discharge).



1500 patients

Definitions of Pulmonary Complications Complications are defined as respiratory infection, postoperative respiratory failure, pleural effusion, pneumothorax, atelectasis, aspiration pneumonia, bronchospasm, need of oxygen supplementation or noninvasive ventilatory support or urgent re-intubation.

Recruitment and Monitoring Procedures

All patients scheduled for elective major abdominal surgery, urologic surgery or major gynecological surgery under general anaesthesia will be enrolled in this study.

Patients will be monitored in the postoperative period and will receive, standard postoperative care, as directed by the clinical teams and if indicated, antibiotics, diuretics, oxygen therapy and every therapy according to the underlying disease. Medical and nursing staff will monitor peripheral oxygen saturation in the origin ward.

Data Collection:

A form divided in three sections (pre/intra/postoperative period) will be used for data collection. Data will be collected on paper support and then entered in an electronic CRF.

Data will be anonymous. Every patient will be identified by a six number code: first three (from left to right) identify the participating center, the others identify the sequential number of enrollment.

The data insertion will be done by the investigators of every participating center, using a personal username and password.

Data will be sent to the coordinator center where the data cleaning will be completed and statistical analysis will be performed with this timing:

  • after the 15 days enrolment period;
  • after 4 months from the beginning of the study (30 days postoperative follow up);
  • after 6 months from the beginning of the study (60 days postoperative follow up);
  • after 16 months from the beginning of the study (1 year postoperative follow up) Every center will store its own paper Case Report Form(CRF).

Sample size Calculation:

1500 patients undergoing elective major abdominal surgery, urologic surgery or major gynecological surgery under general anaesthesia will be enrolled.

On the basis of published studies in the literature (Squadrone et al. (16%), Lawrence et al.(4.5%), Hall et al.(15%), Mitchell et al.(11%) e Canet et al. (7.2%), the investigators supposed that the primary outcome (PaO2/FiO2 <300) will be around 7%. Using a 0.05 two tails alfa, we can obtain a precise two tails 95% confidence intervals (5.8% -8.4% according to the Wald adjusted method), obtaining a sample size of 1422 patients (software STATA 9.0).

Statistical Analysis:

Statistical analysis will be carried out on all collected cases. We will evaluate all the variables considered in the CRF and, for every variable, we will carry out descriptive analysis: mean, median, standard deviation, range, minimum and maximum value for continuous variables; absolute and relative frequencies for categorical variables.

It will also be assessed the possible interdependence between two or more variables and any associations between disease characteristics and therapeutic interventions administered and described in the CRF, using parametric statistical tests, even at multivariate level. We will perform the basic descriptive statistics of the variables considered.

Statistical comparison of continuous variables will be conducted with "t Student test", while "chi square test" will be used for categorical variables. The odds ratio will be calculated and finally logistic regression will be conducted for the analysis of predictivity.

The study also recognizes the possibility to perform additional analysis not planned in the protocol but suggested by the results of planned analyzes described above.

Data will be stored in electronic format and analyzed using the softwares Epi Info 2002 (CDC), SPSS 11.0 (SPSS), and STATA 9.0 (STATA) when appropriate.

Clinical Study Identifier: NCT01914328

Find a site near you

Start Over