Paula Ugalde

Adjustments in cardiorespiratory function after pneumonectomy: Results of the pneumonectomy project

OBJECTIVE To assess lung function, gas exchange, exercise capacity, and right-sided heart hemodynamics, including pulmonary artery pressure, in patients long term after pneumonectomy. METHODS Among 523 consecutive patients who underwent pneumonectomy for lung cancer between January 1992 and September 2001, 117 were alive in 2006 and 100 were included in the study. During a 1-day period, each patient had complete medical history, chest radiographs, pulmonary function studies, resting arterial blood gas analysis, 6-minute walk test, and Doppler echocardiography. RESULTS Most patients (N = 73) had no or only minimal dyspnea. On the basis of predicted values, functional losses in forced expiratory volume in 1 second and forced vital capacity were 38% ± 18% and 31% ± 24%, respectively, and carbon monoxide diffusing capacity decreased by 31% ± 18%. There was a significant correlation between preoperative and postoperative forced expiratory volume in 1 second (P < .01), and more hyperinflation was associated with better lung function (P < .01 for forced expiratory volume in 1 second). Gas exchange was normal at rest (Pao(2) = 88 ± 10 mm Hg; Paco(2) = 42 ± 3 mm Hg), and exercise tolerance (6-minute walk) was also normal (83% ± 17% of predicted values). Thirty-two patients had some degree of pulmonary hypertension, but in most of those cases, it was mild to moderate (mean systolic pressure of 36 ± 9 mm Hg) and not associated with significant differences in lung function (P = .57 for forced expiratory volume in 1 second), gas exchange (P = .08), and exercise capacity (P = .66). CONCLUSIONS These findings indicate that despite worsening of lung function by approximately 30% after pneumonectomy, most patients can adjust to living with only 1 lung. Pulmonary hypertension is uncommon and in most cases only mild to moderate.

Long-Term Physiological Consequences of Pneumonectomy

Ever since the first successful pneumonectomy for lung cancer was performed in 1933, a number of largely historical reports have attempted to look at the physiological consequences of this operation in order to define patient long-term functional status. The pertinence of these contributions is, however, limited because most were performed in patients who had their pneumonectomy for benign diseases or were carried out in small and heterogeneous populations. Thus, several surgical myths and beliefs such as phrenic nerve interruption at the time of operation might be desirable, marked hyperinflation of the residual lung is associated with reduced lung function, and patients develop pulmonary hypertension over time and have poor exercise tolerance have persisted over the years. Our findings based on a study of 100 patients evaluated 5 or more years after surgery (mean follow-up time, 9.1 ± 2.8 years [5.0-14.7 years]) show that most patients can adjust to living with only one lung and are thus able to live a near-normal life. Although diaphragmatic paralysis is characterized by significant alterations in respiratory function, hyperinflation of the residual lung is beneficial.

Correlative Anatomy for the Esophagus

Because the esophagus is a tubular muscular structure only partially filled with air and surrounded by major structures (vessels, lungs, and heart), its radiologic evaluation cannot be performed solely by conventional chest radiograph or barium studies. The emergence of newer techniques has had a dramatic effect on the use of luminal contrast examinations of the gastrointestinal tract. This article describes the current radiographic techniques for examining the gastrointestinal tract with contrast materials, emphasizing the role of barium suspensions, computed tomography scan, and magnetic resonance imaging, and illustrating normal anatomy.

Correlative Anatomy for the Sternum and Ribs, Costovertebral Angle, Chest Wall Muscles and Intercostal Spaces, Thoracic Outlet

The structures of the chest wall and thoracic outlet are complex. A working knowledge of their anatomy and of its variations is essential to any thoracic surgeon working in the area. Correlating imaging with anatomy is just as important if one wants to recognize surgical indications, and potential operating difficulties. In the past, conventional radiographic examination was the norm but interpretation was often difficult and incomplete. Currently, CT and MRI are the best available imaging tools, and most times they have complementary roles in the evaluation of chest wall anatomy.

Correlative Anatomy for Thoracic Inlet; Glottis and Subglottis; Trachea, Carina, and Main Bronchi; Lobes, Fissures, and Segments; Hilum and Pulmonary Vascular System; Bronchial Arteries and Lymphatics

Because it is relatively inexpensive and universally available, standard radiographs of the thorax should still be viewed as the primary screening technique to look at the anatomy of intrathoracic structures and to investigate airway or pulmonary disorders. Modern trained thoracic surgeons must be able to correlate surgical anatomy with what is seen on more advanced imaging techniques, however, such as CT or MRI. More importantly, they must be able to recognize the indications, capabilities, limitations, and pitfalls of these imaging methods.

What the cardiologist should know about the management of platypnea-orthodeoxia syndrome.

Platypnea–orthodeoxia syndrome is a rare and poorly understood condition related to the development of a right-to-left intracardiac shunt at the atrial level through a benign and silent patent foramen ovale. It is usually recognized after major lung resection, recurrent pulmonary embolism or chronic lung disease. Orthostatic dyspnea and cyanosis is the prominent clinical presentation. Symptoms increase in the upright position and are relieved by recumbency. Our report describes the clinical course of a patient with severe hypoxemia after left pneumonectomy attributable to a right-to-left shunting through an atrial septal defect.

Correlative Anatomy for the Mediastinum

Diseases of the mediastinum comprise a wide spectrum of benign and malignant entities that share the same anatomic site within the chest. Correct management often requires a multidisciplinary approach. Diagnostic imaging modalities such as computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography, and positron emission tomography play a major role in the diagnosis of mediastinal diseases and in guiding minimally invasive diagnostic procedures, minimizing the risk of imaging-guided biopsies. This article describes the mediastinal anatomy, correlating the findings of plain radiography, CT, and MRI.

Lung re-inflation after one-lung ventilation for thoracic surgery: an alternative technique

To the Editor, We read with great interest the correspondence from Dr. Bruin concerning the importance of clamping the dependent lung lumen of the double-lumen endobronchial tube and suspending ventilation of the non-operative lung when the non-dependent lung, having just undergone surgery, is to be re-inflated. As mentioned by Dr. Bruin, clamping the dependent lung during re-expansion of the non-dependent lung protects it against volutrauma and avoids possible pulmonary tamponade and secondary hypotension. We prefer, however, to use a secondary auxiliary breathing circuit to ventilate the non-dependent lung manually. This method allows us to take the time needed to overcome atelectatic areas slowly and progressively and to check for air leaks with minimal risk of staple line disruption. Most importantly, the dependent lung remains ventilated with the same one-lung ventilation parameters. In addition, as this secondary breathing circuit is independent of the main ventilation circuit, we can use it at any time during the operation. For example, it can be used when the surgeon wants to either verify an air leak from a bronchial stump or staple line or re-expand other lobes to confirm proper stapler placement (particularly during thoracoscopic cases). This circuit (Bain breathing circuit, Hudson RCI, distributed by Teleflex Medical, Research Triangle Park, NC, USA) can also be used to apply continuous positive airway pressure to the operated lung, although it would be needed infrequently for this purpose. The auxiliary ventilatory circuit can be either a Hyperinflation System (Mercury Medical, Clearwater, FL, USA) or a Bain circuit (Figure) and must be equipped with a manometer to protect the lung from barotraumas. The advantage of using two independent breathing systems is that they allow us to maintain stable ventilation of the dependent lung during intervention on the operative lung. We believe that an independent breathing circuit is an excellent alternative to clamping the dependent lung during thoracotomy, particularly in this era of increasing video-assisted thoracoscopic surgery where the surgeon frequently asks for ‘‘small inflations’’ of the lung undergoing surgery.