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Correspondence  |   July 2011
Don't Forget the Heart When Looking at the Risk of Postoperative Pulmonary Complications
Author Affiliations & Notes
  • Marc Fischler, M.D.
    *
  • *Hôpital Foch, Suresnes, France.
Article Information
Correspondence
Correspondence   |   July 2011
Don't Forget the Heart When Looking at the Risk of Postoperative Pulmonary Complications
Anesthesiology 7 2011, Vol.115, 210. doi:10.1097/ALN.0b013e31821f6494
Anesthesiology 7 2011, Vol.115, 210. doi:10.1097/ALN.0b013e31821f6494
To the Editor:
We read with great interest the recent study by Canet et al.  1 In this investigation, based on 2,464 surgical patients, the incidence of postoperative pulmonary complications (PPCs) was 5%, with a related mortality rate at Day 30 of 19.5% (95% CI, 12.5–26.5%).
Predicting risk factors for PPCs is a cornerstone of better patient management. However, reliable knowledge of PPC incidence in a broad, heterogeneous surgical population remains difficult because of nonrepresentative samples and statistical flaws. Furthermore, definitions of PPC are often not explicit and differ among studies. The recent study of Canet et al.  1 has similarities with that of McAlister et al.  2 Both investigations were built with a strong statistical methodology and included a large representative surgical population. Yet, the 5% incidence of PPC reported by Canet et al.  1 is almost double the 2.7% reported by McAlister et al.  2 This higher rate of complications observed by Canet et al.  1 could be explained, in part, by the inclusion of emergency cases (14.2%), whereas McAlister et al.  2 included only scheduled cases. The risk of PPC increases significantly in emergency cases.3 In addition, Canet et al.  1 included some thoracic surgical cases. Another major difference is related to the use of different PPC definitions. The diagnostic criteria used by McAlister et al.  2 were stricter, including supplementary therapeutic action, such as mechanical ventilation for respiratory failure, percutaneous intervention for treatment of pleural effusion, and bronchoscopic intervention for atelectasis.2 
Nevertheless, the most striking result reported by Canet et al.  1 is not the high incidence of PPC per se  but the high percentage of mortality (19.5%) associated with these cases. It seems difficult to conceive that PPC alone can explain this finding. A previous study by Lawrence et al.  4 showed that, in a cohort of patients undergoing major abdominal surgery, 33% who developed PPC also had cardiovascular complications. This result suggests that a significant proportion of patients studied by Canet et al.  1 also had cardiovascular complications that were not evaluated and that these complications may have been the cause of death in these patients.
In conclusion, further studies are necessary to examine prospectively comparative incidence, outcomes, and predictors of both types of complications.
*Hôpital Foch, Suresnes, France.
References
Canet J, Gallart L, Gomar C, Paluzie G, Vallès J, Castillo J, Sabaté S, Mazo V, Briones Z, Sanchis J, ARISCAT Group: Prediction of postoperative pulmonary complications in a population-based surgical cohort. Anesthesiology 2010; 113:1338–50Canet, J Gallart, L Gomar, C Paluzie, G Vallès, J Castillo, J Sabaté, S Mazo, V Briones, Z Sanchis, J ARISCAT Group,
McAlister FA, Bertsch K, Man J, Bradley J, Jacka M: Incidence of and risk factors for pulmonary complications after nonthoracic surgery. Am J Respir Crit Care Med 2005; 171:514–7McAlister, FA Bertsch, K Man, J Bradley, J Jacka, M
Smetana GW, Lawrence VA, Cornell JE, American College of Physicians: Preoperative pulmonary risk stratification for noncardiothoracic surgery: Systematic review for the American College of Physicians. Ann Intern Med 2006; 144:581–95Smetana, GW Lawrence, VA Cornell, JE American College of Physicians,
Lawrence VA, Dhanda R, Hilsenbeck SG, Page CP: Risk of pulmonary complications after elective abdominal surgery. Chest 1996; 110:744–50Lawrence, VA Dhanda, R Hilsenbeck, SG Page, CP