Case Communications

Mediastinal Shift toward the Remaining : A Report of Six Cases

Ilan Bar MD FCCP, Michael Papiashvili MD and Benny Zuckermann MD

General Thoracic Surgery Unit, Assaf Harofeh Medical Center, Zerifin, Israel Affiliated to Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel

Key words: postpneumonectomy, cancer, lung, , shift IMAJ 2007;9:885–886

Deviation of the mediastinum towards the num was in the midline with air filling the removed was 1300 ml (mean 900 ml). remaining lung after pneumonectomy may post-pneumonectomy cavity. Clinical improvement was immediate upon produce symptomatic airway obstruction The six patients complained of dis- chest tube insertion, and a reshift of the by lung compression, thereby impairing abling dyspnea and onset weakness 1 to mediastinum towards the empty cavity venous return. This is a rare post-pneumo- 2 weeks after surgery. They all underwent was confirmed by repeat chest X-ray. nectomy complication and may occur not extensive evaluation to rule out other The patients stabilized over the next only in the early postoperative period but causes of dyspnea, such as pulmonary 24 hours with an increase in urine output, also at a later stage after surgery. A late hypertension, pulmonary edema, air leak, an elevated level of pO2 (ranging from 62 (more than 1–2 weeks after surgery) shift chronic obstructive pulmonary disease to 78), elevated blood pressure, and a of the mediastinum towards the opposite exacerbation, pneumonia and myocardial reduction in rate and central venous lung after pneumonectomy may produce infarction. The tests included physical ex- pressure. The monitors were disconnected compression of mediastinal structures and amination, chest X-rays, electrocardio- and the patients were discharged home airway compromise, leading to dyspnea on graphic monitoring, blood gas analyses, a in good health 48 hours after chest tube minimal exertion and low cardiac output. central venous catheter, a Foley catheter, removal. Follow-up did not reveal any If the mediastinum has not yet been an arterial line and a bedside echocar- abnormalities during the ensuing 12 stabilized, decompression of the post- diogram. All six patients received 100% months. pneumonectomy cavity may be sufficient oxygen through a face mask and were to relieve the symptoms. Therefore, early hemodynamically stabilized by fluids or Comment diagnosis and management are essential. blood products as needed. They were fully Pneumonectomy continues to be associ- monitored and continuously evaluated by ated with high rates of morbidity and Patient Descriptions means of blood saturation analyses and mortality (7–11%) [1]. Following complete Six patients with a shift of the medi- thermometer measurements. Chest X-rays pneumonectomy, the pleural space is astinum towards the remaining lung showed complete or nearly complete reduced due to increased expansion of after pneumonectomy were treated in opacification of the post-pneumonectomy the remaining lung and a shift of the our department between 1998 and 2004 cavity and a shift of the mediastinum mediastinum and diaphragm towards the (these patients comprised 6.5% of the 92 towards the remaining lung. Blood gas newly created space. The fluid that fills pneumonectomies performed during this analyses revealed low partial pressure of the space increases until the postoperative period). There were four males and two oxygen in blood content (ranging from is obliterated, a process females, with a mean age at pneumo- 55 to 68), ECG monitoring showed sinus that takes 2 weeks on average, at which nectomy of 67.2 (range 54–80 years). The tachycardia (> 100 beats/min), urinary time the mediastinum is stabilized in the reasons for pneumonectomy were non- output was reduced (< 30 ml/hour), and midline of the chest cavity [2]. small cell lung carcinoma in five cases central venous pressure was elevated (> Proper positioning of the mediastinum and atypical carcinoid in one. 12–14 mmHg). Trans-thoracic echocardiog- is critical in the immediate postoperative After pneumonectomy a 32 French raphy ruled out pulmonary hypertension period and is usually achieved by indwell- size trocar catheter (Tyco Healthcare UK or cardiac dysfunction as causes of the ing thoracic catheters or needle aspiration Ltd, Gosport, UK) chest tube connected dyspnea. Due to the absence of other of air (thoracentesis) from the empty to a high capacity chest drainage system possible causes, the shift of the medias- chest cavity. Improper positioning of the (Thorametrix, Biometrix, Jerusalem, Israel) tinum was suspected to be the cause of mediastinum may contribute to a shift of was inserted in all the patients and re- the symptoms. the mediastinum towards the contralateral moved 24 hours later. The position of the A chest tube was inserted into the side following post-pneumonectomy, re- mediastinum was controlled by daily chest post-pneumonectomy cavity under local sulting in many devastating complications, X-rays. At the time of patient discharge, anesthesia with 30–40 ml of 1% lidocaine.

5–7 days following surgery, the mediasti- The maximum volume of pleural fluid pO2 = partial pressure of oxygen in the blood

• Vol 9 • December 2007 Mediastinal Deviation 885 Case Communications such as arrhythmias, pulmonary edema, ing factors: inadequate management of References or sudden death. Conversely, accumulated the post-pneumonectomy pleural space 1. Watanabe S, Asamura H, Suzuki K, fluid or retained air in the empty space after surgery, hemorrhage, new-onset Tsuchiya R. Recent results of postopera- shifts the mediastinum towards the broncho-pleural fistula, and microscopic tive mortality for surgical resections in remaining lung with compromise of pul- pleural metastasis that may not have lung cancer. Ann Thorac Surg 2004;78:999– 1002. monary function and severe cardio-respi- been seen during surgery [5] and can 2. Wolfe WG, Lewis CW Jr. Control of the ratory failure. Early post-pneumonectomy be the cause of a massive early pleural pleural space after pneumonectomy. Chest complications, induced by deviation of effusion. Surg Clin North Am 2002;12:565–70. the mediastinum towards the remaining Mediastinal shift should be suspected 3. Deslauriers J, Gregoire J. Techniques of lung, significantly increase postoperative in patients presenting with dyspnea one pneumonectomy. Drainage after pneumo- nectomy. Chest Surg Clin North Am 1999;9: morbidity and mortality in the first days or more weeks after pneumonectomy. 437–48. after surgery and may be controlled by We consider the timing of the diagnosis 4. Valji AM, Maziak DE, Shamji FM, Matzi­ various methods [2,3]. – a late shift of the mediastinum towards nger FR. Postpneumonectomy syndrome: Late complications of pneumonec- the remaining lung – to be critical in the recognition and management. Chest 1998; tomy induced by a shift and rotation management of these patients because 114:1766–9. 5. Enatsu S, Yoshida J, Yokose T, et al. Pleu- of the mediastinum towards the post- of the respiratory and possible cardiac ral lavage cytology before and after pneumonectomy side have also been compromises that could jeopardize their lung resection in non-small cell lung described (post-pneumonectomy syn- lives, as seen in the six cases treated in cancer patients. Ann Thorac Surg 2006;81: drome) [4], but the late (> 1–2 weeks) our department. In addition, mediastinal 298–304. shift of the mediastinum towards the repositioning in the relatively late postop- Correspondence: Dr. I. Bar, Head, General remaining lung and symptoms induced erative period is very difficult. Chest tube Thoracic Surgery Unit, Assaf Harofeh Medi- by this shift have not yet been com- insertion provides symptomatic relief and cal Center, Zerifin 70300, Israel. pletely reviewed. Improper positioning clinical improvement, but simple thora- Phone: (972-8) 977-9822, of the mediastinum 1–2 weeks after sur- centesis may also be helpful in the initial Fax: (972-8) 977-8149 gery could be due to any of the follow- management. email: [email protected]

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Capsule Sweet smell What makes one smell pleasant and another odious? Is there that the data fell along an axis that describes the “pleasantness something in the chemistry of a substance that can serve rating” of the odors – running from “sweet” and “flowery” at one to predict how we will perceive its smell? Scientists at the end to “rancid” and “sickening” at the other. To their surprise Weizmann Institute of Science and the University of California they found that the same distribution along this axis clearly at Berkeley have now discovered that there is indeed such a describes the variation in chemical and physical properties link, and knowing the molecular structure of a substance can from one substance to another. From this, they could build a help predict whether we will find its smell heavenly or malodor- model to predict, from the molecular structure of a substance, ous. In sight and hearing, for instance, our perceptions are how pleasing its smell would be perceived. To double-check determined by the physical properties of waves – the length their model, they tested how subjects assessed 50 odors they of light waves in seeing, and the frequency of sound waves had never smelled before for pleasantness. The ratings for in hearing. But until now there was no known physical factor their test subjects fit closely with the ranking shown by the that could explain how our brains sense odors. To identify the model. In other words, they were able to predict the level general principles by which our sense of smell is organized, the of pleasantness, even for unfamiliar smells. They noted that researchers began with a database of 160 different odors that although preferences for smells are commonly considered to had been ranked by 150 perfume and smell experts according be culturally learned, their study showed that the response of to a set of 146 characteristics (sweetish, smoky, musty, etc.). American subjects, Jewish Israelis and Muslim-Arab Israelis all Using these data, a statistical program analyzed the variance fit the model’s predictions to the same extent. in perception among the smell experts. The researchers found Israel High-Tech & Investment Report, October 2007

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