A Simple Solution to the “Foam” Problem

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for long-term survival after surgery for nonsmall cell lung cancer (NSCLC). Preoperative and predicted postoperative lung volumes have been extensively used in predicting immediate postoperative complications and respiratory insufficiency, but considering it as a prognosticator of long-term outcomes injects fresh thought into the subject. It is also interesting to note that most deaths in the study were unrelated to the primary cancer. However, to recommend avoidance of lobectomy in patients with a preoperative forced expiratory volume in 1 second (FEV1) ⬍ 70% seems a bit extreme. In their study, age, gender, and preoperative FEV1 ⬍ 70% were considered poor prognostic factors among patients with stage I NSCLC. Based on this finding the authors have recommended that “lobectomy may not be the preferred surgical modality for patients with stage I NSCLC with poor FEV1.” By this logic, lobectomy should not be recommended in elderly males as well. The morbidity of lobectomy is extremely low with no change in exercise capacity and causes insignificant reductions in FEV1, peak heart rate, oxygen consumption, minute ventilation, oxygen saturation, and respiratory exchange ratio [2]. Also patients with chronic obstructive pulmonary disease may actually have improvement of their lung function after an upper lobectomy [3]. In a decision analysis model, what needs to be determined is not the outcome of patients with FEV1 ⬍ 70% as compared with patients with a better FEV1, but rather what their outcome would have been if they have had sublobar resections. It is quite possible that the patients who died in the group who had FEV1 ⬍ 70% may have died even with sublobar resections. The Lung Cancer Study Group trial [4] showed inferior survival for sublobar resections both in their initial report as well as their updated results. Hence, to recommend a suboptimal cancer control surgery for the entire cohort of patients with FEV1 ⬍ 70% would unfairly deny these patients their best chance for cure. C S Pramesh, MS, FRCS Rajesh C Mistry, MS Jaiprakash Agarwal, MD K Arvind, MS

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Division of Thoracic Surgery Department of Radiotherapy Tata Memorial Hospital Mumbai 400012, India e-mail: [email protected]

References 1. Iizasa T, Suzuki M, Yasufuku K, et al. Preoperative pulmonary function as a prognostic factor for stage I non-small cell lung cancer. Ann Thorac Surg 2004;77:1896 –903. 2. Nugent AM, Steele IC, Carragher AM, et al. Effect of thoracotomy and lung resection on exercise capacity in patients with lung cancer. Thorax 1999;54:334 – 8. 3. Korst RJ, Ginsberg RJ, Ailawadi M, et al. Lobectomy improves ventilatory function in selected patients with server COPD. Ann Thorac Surg 1998;66:898 –902. 4. Ginsberg RJ, Rubinstein LV. Randomized trial of lobectomy versus limited resection for T1 N0 non-small cell lung cancer. Ann Thorac Surg 1995;60:615–23.

Reply To the Editor: We appreciate the comments of Dr Pramesh and colleagues on our article, but would like to provide some clarification. They suggest that we have recommended limited surgery to patients with a percentage of forced expiratory volume in 1 second © 2005 by The Society of Thoracic Surgeons Published by Elsevier Inc

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(FEV1%) ⬍ 70%. However, FEV1% is a continuous variable, and we compared all statistically significant prognostic factors with the continuous variables of age, pack-years, FEV1%, percentage of forced vital capacity, and PaCo2. Each border of 60% and 70% FEV1% is not related to a border between lobectomy and limited surgery, and we do not mean to recommend that lobectomy be withheld from all patients with a preoperative FEV1% ⬍ 70%. Moreover, we also had the same experience with the volume reduction effect after lobectomy in severe chronic obstructive pulmonary disease patients as they and D’Amico [1] pointed out [2]. However, Pramesh and colleagues do not claim that patient lung function is normalized; they simply report that lung function improves. They do not discuss a correlation of long-term survival with lung function. We cannot confirm a lower limit of FEV1% for lobectomy of nonsmall cell lung carcinoma (NSCLC) patients from our data, just as an upper age limit for lobectomy cannot be determined. The aim of this retrospective study was not to decide a cutoff point of lung function for lobectomy in stage I NSCLC, but to consider a lower preoperative FEV1%, as well as other prognostic factors to reflect postoperative long-term survival in these cases. Hereafter, we would evaluate more cases of limited surgery with our results, taking into account the perioperative death rates of patients with a lower percentage of forced expiratory volume in 1 second comprehensively as well. Toshihiko Iizasa, MD Takehiko Fujisawa, MD Department of Thoracic Surgery Graduate School of Medicine, Chiba University 1-8-1 Inohana Chuo-ku Chiba, 260-8670 Japan e-mail: [email protected]; [email protected]

References 1. D’Amico TA. Preoperative pulmonary function as a prognostic factor for stage I non-small cell lung carcinoma. Ann Thorac Surg 2004;77:1902–3. 2. Korst RJ, Ginsberg RJ, Ailawadi M, et al. Lobectomy improves ventilatory function in selected patients with server COPD. Ann Thorac Surg 1998;66:898 –902.

A Simple Solution to the “Foam” Problem To the Editor: Cesario and colleagues [1] address a problem that thoracic surgeons face when using an Emerson or Bulau suction apparatus (J. H. Emerson Co, Cambridge, MA) with a persistent moderate to large bronchopleural fistula. With the air leak, foam above the water seal is created as the result of surface tension supported by the protein content of the pleural fluid [2]. The authors advise the use of simethicone in reducing the protenacious material above the water seal. Simethicone may not be available in the hospital and may require special order. A much simpler and readily available solution exists. Isopropyl alcohol (or rubbing alcohol) is readily available in all hospitals and in every nursing station. 5 to 15 mL of this is introduced into the bottle and the foam immediately disappears. The protein in the fluid is denatured by the alcohol and the bubbles are no longer supported by surface tension. An application typically lasts for 24 hours. I thank Cesario and colleagues [1] for calling attention to this technical problem in the post operative care of the persistent 0003-4975/05/$30.00

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Fred Weber, MD, JD Thoracic Surgery Atlantic Thoracic, PA 10 W Connecticut Ave Somers Point, NJ 08244 – 0111 e-mail: [email protected]

References 1. Cesario A, Galetta D, Margaritora S, et al. Persistent air leak after pulmonary resection: the water-valve “foam” problem. Ann Thorac Surg 2004;78:389 –90. 2. Rice TW, Okereke IC, Blakstone EH. Persistent air-leak following pulmonary resection. Chest Surg Clin N Am 2002;12:529 –39.

Reply To the Editor: We welcome the kind comment of Dr Weber regarding our recent brief communication [1] reporting a simple “trick” to overcome the “foam” problem arising into the Boulau water valve system when continuous suction is applied to front a persistent air leakage after lung parenchyma resections. The use of a few drops of simethicone, which is the method we reported, is effective, virtually costless, and harmless. Simethicone is widely available in our hospital. The use of isopropyl-alcohol as reported by Dr Weber appears to be effective as well. We raise some toxicological safety and occupational concerns. According to the Occupational Safety & Health Administration and the United States Department of Labor (http:// www.osha.gov/SLTC/healthguidelines/isopropylalcohol/ recognition.html), isopropyl alcohol is flammable and contact with air may cause formation of dangerous peroxides and hazardous decomposition products (toxic gases) in case of fire. Furthermore, under normal circumstances, greater than a certain concentration of isopropyl alcohol is toxic (acutely and chronically). Moreover, the professional use of isopropyl alcohol is to be planned according to the occupational exposure limits as indicated by the Occupational Safety and Health Administration (OSHA). In Italy we have similar restrictions with the use of “hazardous” and “flammable” substances and, under no circumstances would we use isopropyl alcohol in a water-valve system connected to a patient who is frequently receiving continuous oxygen therapy. Alfredo Cesario, MD Stefano Margaritora, MD Venanzio Porziella, MD Kenji Kawamukai, MD Domenico Galetta, MD Pierluigi Granone, MD General Thoracic Surgery Catholic University Largo Agostino Gemelli, 8 Rome, 00168 Italy Clinical Respiratory Pathology Translational Laboratory IRCCS San Raffaele Via della Pisana, 235 Rome, 00163 Italy e-mail: [email protected] © 2005 by The Society of Thoracic Surgeons Published by Elsevier Inc

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References 1. Cesario A, Galetta D, Margaritora S, et al. Persistent air leak after pulmonary resection: the water-valve “foam” problem. Ann Thorac Surg 2004;78:389 –90.

Risk Factors for Respiratory Failure: Differentiating Association and Outcome To the Editor: Canver and Chanda [1] identify factors that increase the risk of respiratory failure after coronary artery bypass grafting. Established difficulties associated with predicting outcome after this operation include ambiguous factor and outcome definitions [2], questionable data reliability [3], variability in methodological approach [4], and the continued neglect of postoperative measures as indicators of complication risk or outcome [5]. Outcomes must be important to patients, relatively common, and linked logically and causally to service providers [3]. The authors claim the inclusion of postoperative variables in a multivariate analysis designed to predict the risk factors for the need of postoperative mechanical ventilatory support for more than 72 hours. This outcome has major implications for patients and providers. However, Canver and Chanda fail to make the important distinction between variables as predictors of increased risk and variables that are, by circumstance, associated with the outcome of interest. Examining complications as predictors disregards the multifactor contribution of antecedents to complications that in this instance can also influence the need of prolonged ventilatory support. Patients will not be extubated in the context of hemodynamic instability and inability to safely maintain a patent airway secondary to septicemia, stroke, or bleeding that requires reexploration. Postoperative patient and process variables have long been neglected, as is reflected in predictive models that account for small proportions of variation in patient outcome. Although efforts of Canver and Chanda to overcome this discrepancy are acknowledged, the value of postoperative patient factors and care processes in combination warrants further exploration for the adequate prediction of pulmonary dysfunction after cardiac surgical procedures. Rochelle M. Wynne, RN, MEd The Alfred/Deakin Nursing Research Centre School of Nursing Deakin University 221 Burwood Hwy Burwood, Melbourne VIC 3125, Australia e-mail: [email protected]

References 1. Canver CC, Chanda J. Intraoperative and postoperative risk factors for respiratory failure after coronary bypass. Ann Thorac Surg 2003;75:853– 8. 2. Turner JS, Morgan CJ, Thakrar B, Pepper JR. Difficulties in predicting outcome in cardiac surgery patients. Crit Care Med 1995;23:1843–50. 3. Iezzoni LI. Using risk-adjusted outcomes to assess clinical practice: an overview of issues pertaining to risk adjustment. Ann Thorac Surg 1994;58:1822– 6. 4. Fortescue EB, Kahn K, Bates DW. Prediction rules for complications in coronary bypass surgery: a comparison and methodological critique. Med Care 2000;38:820 –35. 5. Shroyer AL, London MJ, Sethi GK, Marshall G, Grover FL, Hammermeister KE. Relationships between patient-related 0003-4975/05/$30.00

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bronchopleural fistula. I propose a simple and more convenient solution to the problem.

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