A. Patients scheduled for thoracic surgery should undergo the usual preoperative assessment as detailed in Chapter 1.

1. Any patient undergoing elective thoracic surgery should be carefully screened for underlying bronchitis or pneumonia and treated appropriately before surgery.

a. Diagnostic procedures such as bronchoscopy and lung biopsy may be indicated for persistent infection.

b. Infection beyond an obstructing lesion may not resolve without surgery.

2. In patients with tracheal stenosis, the history should focus on symptoms or signs of positional dyspnea, static versus dynamic airway collapse, and evidence of hypoxemia. The history may also suggest the probable location of the lesion.

B. An arterial blood gas (ABG) may help clarify the severity of underlying pulmonary disease but is not routinely necessary.

C. Pulmonary function tests are useful for assessing the pulmonary risk of lung resection. Forced expiratory volume in 1 second (FEV1) and diffusion capacity of the lung for carbon monoxide (DLCO) serve as initial predictors of postoperative outcomes. Marginal results of these tests may prompt additional studies, including postoperative predicted FEV1, ventilation/perfusion (V/Q) scans, and exercise function testing of maximal oxygen uptake ([V with dot above]o_2max) to stratify risks of resection.

D. Cardiac function should be assessed if there is a question about the relative contribution of cardiac and pulmonary diseases to the patient’s functional impairment. Echocardiography can be used to assess right ventricular function. Echocardiographic estimation of right ventricular systolic pressure can be used as a screening tool for pulmonary hypertension, although, right heart catheterization is required for definitive diagnosis.

E. Chest radiography, computed tomography (CT), and magnetic resonance imaging (MRI) are useful to determine the presence and extent of tracheobronchial, pulmonary and mediastinal pathology. Imaging studies can also reveal the nature and degree of involvement of other thoracic structures in the disease process.

F. Three-dimensional reconstruction from CT is used to assess the caliber of stenotic airways and can be used to predict the size and length of the endotracheal tube that will be appropriate for the patient. Severe airway stenosis may change the anesthetist’s plans for induction and intubation.

A. Preoperative sedation should be given carefully to patients with tracheal or pulmonary disease.

1. Heavy sedation may impair postoperative deep breathing, coughing, and airway protection. Patients with poor pulmonary function will be more prone to hypoxemia when their respiratory drive is suppressed. When sedating these patients, it is prudent to monitor oxygenation and administer supplemental oxygen.

2. In the presence of airway obstruction, sedation must be carefully balanced. It is crucial to maintain spontaneous ventilation. Oversedation may profoundly suppress ventilation, but an anxious patient may make exaggerated respiratory efforts. In this case, the increased turbulence may worsen airway obstruction, leading to increased anxiety. Benzodiazepines, reassuring words, careful monitoring, and an expeditious start to the procedure are the best approach. In patients with airway stenosis, Heliox, a mixture of 79% helium and 21% oxygen, will lower the density of the respiratory gas and reduce airway resistance.

B. Glycopyrrolate (0.2 mg intravenously) may be given to decrease oral secretions.

A. Mediastinoscopy is conducted to evaluate the extrapulmonary spread of pulmonary tumors and to investigate mediastinal masses. Mediastinoscopy is performed through an incision just superior to the manubrium. A rigid endoscope is then introduced beneath the sternum, and the anterior surfaces of the trachea and the hilum are examined. The patient is supine with the neck extended.

1. Any general anesthetic technique may be used, provided the patient remains immobile. Although the procedure is not very painful, intermittent stimulation of the trachea, carina, and mainstem bronchi occurs.

2. Complications include pneumothorax, rupture of the great vessels, and damage to the airways. Large-bore IV access is required, and the patient should have blood cross-matched in the case of hemorrhage. IV access should be placed in the right upper extremity as the left innominate vein may be compressed during mediastinoscopy. There is a risk of stroke from innominate artery occlusion by compression between the mediastinoscope and the posterior surface of the sternum. As stated previously, perfusion to the right arm should be monitored by pulse oximetry or blood pressure measurement. Blood pressure monitoring in the left arm is essential to monitor systemic blood pressure in the event of innominate arterial compression. Should innominate arterial compression occur and the surgeon be incapable of relieving the pressure (i.e., while managing hemorrhage through the mediastinoscope), the mean systemic pressure must be increased to encourage collateral flow to the right cerebral hemisphere. The trachea may be intermittently compressed by the mediastinoscope, and the position of the patient and surgeon increases the chance of accidental disconnection of the breathing circuit.

B. Chamberlain procedure uses an anterior parasternal incision to obtain lung or anterior mediastinal tissue for biopsy or to drain abscesses. The incision is typically in the left second intercostal interspace. The patient is supine.

1. Following the induction of general anesthesia, the procedure is performed with the patient in the supine position. If no ribs are resected, the procedure is usually not very painful. Infiltration of the incision with local anesthetic or administration of small doses of opioids and/or IV nonsteroidal anti-inflammatories is usually sufficient for analgesia.

2. One-lung ventilation is not required for lung biopsy, but manual ventilation in cooperation with the surgeon(s) can facilitate the procedure.

3. If the pleural space is evacuated as it is closed, a chest tube generally is not required postoperatively, although the patient should be monitored carefully for any signs of pneumothorax.

1. Median sternotomy is performed for resection of mediastinal tumors and for bilateral pulmonary resections. In descending order of frequency, mediastinal masses include neurogenic tumors, cysts, teratodermoids, lymphomas, thymomas, parathyroid tumors, and retrosternal thyroids.

2. Thymectomy is performed by median sternotomy and may be performed to treat myasthenia gravis. Anesthetic considerations for the patient with myasthenia gravis are detailed in Chapter 13.

3. General anesthesia may be induced and maintained with any technique.

a. Neuromuscular blockers are not required to maintain surgical exposure but may be a useful adjunct to general anesthesia. Both nondepolarizing and depolarizing muscle relaxants are best avoided in the myasthenic patient.

b. During the actual sternotomy, the patient’s lungs should be deflated and motionless. Even so, complications of sternotomy include laceration of the right ventricle, atrium, or great vessels (particularly the innominate artery) and unrecognized pneumothorax in either side of the chest.

c. Postoperative pain from a median sternotomy is significantly less than from a thoracotomy and may be managed with either an epidural or parenteral opioids.

1. Lateral or posterolateral thoracotomy is an approach for the resection of large pulmonary neoplasms or abscesses. Thoracotomy is often preceded by staging procedures such as bronchoscopy, mediastinoscopy, or thoracoscopy. If the staging procedures are performed at the same sitting, the anesthetic should be planned to accommodate the possibility of a shortened procedure if metastatic disease is discovered.

2. Video-assisted thoracoscopic surgery (VATS) is a common approach for wedge resection, segmentectomy, and lobectomy. Thoracoscopic surgery may result in less postoperative pain and a shorter recovery time. Lung isolation is required for adequate visualization of the surgical field.

3. Robot-assisted thoracoscopic surgery is an emerging technique that is theoretically superior to VATS in that the accuracy of the robotic arm facilitates lymph node resection with the conservation of nerves and improved cure rates.

a. Good pressure point padding must be ensured due to extremes of positioning with robotic surgery.

b. When the robot is docked, the surgical bed must not be moved at all.

c. As with VATS, complete collapse of the operative lung must be maintained.

B. Endobronchial Tubes. Placement of a double-lumen tube is indicated for lung protection (for significant hemoptysis or unilateral infection), bronchoalveolar lavage, or surgical exposure.

a. Double-lumen tubes range in size from 26 to 41 French. In general, a 39- or 41-French tube is chosen for adult males and a 35- or 37-French is chosen for adult females. Selection is also based on the patient’s height. In general, for men, 70 inches is used for a cutoff height between the 39- or 41-French tubes. For women, 65 inches is a cutoff between 35 or 37 French.

b. Right- and left-sided double-lumen tubes are available and are designed to conform to either the right or the left mainstem bronchus. Each tube has separate channels: one for ventilation of the bronchus and the other for the trachea and nonintubated bronchus. Right-sided tubes have a separate opening in the bronchial lumen to permit ventilation of the right upper lobe.

c. The choice of a left- or right-sided tube depends on the type and side of operation. If a mainstem bronchus is absent, stenotic, disrupted, or obstructed, the double-lumen tube must be placed on the opposite side, preferably under direct fiberoptic guidance. In most cases, the choice of a left- versus right-sided tube is not so absolute. Most surgical procedures can be performed with a left-sided double-lumen tube. It is our practice, however, to selectively intubate the dependent (nonoperative) bronchus. This ensures that the endobronchial tube will not interfere with resection of the mainstem bronchus if this is necessary. Also, if the nondependent lung is intubated, ventilation of the dependent lung through the tracheal lumen may be compromised by mediastinal pressure pushing the tube against the tracheal wall and creating a “ball-valve” obstruction.

a. The endobronchial tube, including both cuffs and all necessary connectors, should be carefully checked before placement. The tube may be lubricated, and a stylet should be placed in the bronchial lumen.

b. After laryngoscopy, the endobronchial tube should be inserted initially with the distal curve facing anteriorly. Once in the trachea, the stylet should be removed and the tube rotated so that the bronchial lumen is toward the appropriate side. The tube is then advanced to an average depth of 29 cm at the incisors or gums (27 cm in females) or less if resistance is met.

c. Alternatively, a fiberoptic bronchoscope can be passed down the bronchial lumen as soon as the tube is in the trachea and then used to guide the tube into the correct mainstem bronchus.

d. Once the tube has been inserted and connected to the anesthesia circuit, the tracheal cuff is inflated, and manual ventilation is initiated. Endotracheal placement is confirmed by the presence of end-tidal CO₂ and the auscultation of bilateral breath sounds and no detectable air leak. The tracheal side of the adapter is then clamped, and the distal tracheal lumen is opened to atmospheric pressure via the access port. The bronchial cuff is inflated to a point just sufficient to eliminate air leak from the tracheal lumen, and the chest is auscultated. Breath sounds should now be limited to the side that has been endobronchially intubated. Moving the clamp to the bronchial side of the adapter and closing the tracheal access port should cause only the nonintubated side to be ventilated.