Anesthesia for Thoracic Surgery - Preoperative Evaluation
Patients scheduled for thoracic surgery
Patients scheduled for thoracic surgery should undergo the usual preoperative assessment as detailed in Chapter 1.
- Any patient undergoing elective thoracic surgery should be carefully screened for underlying bronchitis or pneumonia and treated appropriately before surgery.
- Diagnostic procedures such as bronchoscopy and lung biopsy may be indicated for persistent infection.
- Infection beyond an obstructing lesion may not resolve without surgery.
- 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.
An arterial blood gas (ABG)
An arterial blood gas (ABG) may help clarify the severity of underlying pulmonary disease but is not routinely necessary.
Pulmonary function tests
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
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.
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.
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.