- During one-lung ventilation, the mixing of
unoxygenated blood from the collapsed upper lung with oxygenated
blood from the still-ventilated dependent lung widens the Pa–a (alveolar-to-arterial)
O2 gradient and often results in hypoxemia.
- Malpositioning of a double-lumen tube is usually
indicated by poor lung compliance and low exhaled tidal volume.
- If epidural opioids are to be used postoperatively,
their intravenous use should be limited during surgery to prevent
excessive postoperative respiratory depression.
- Postoperative hemorrhage complicates about 3% of
thoracotomies and may be associated with up to 20% mortality.
Signs of hemorrhage include increased chest tube drainage (> 200
mL/h), hypotension, tachycardia, and a falling hematocrit.
- Bronchopleural fistula presents as a sudden large
air leak from the chest tube that may be associated with an increasing
pneumothorax and partial lung collapse.
- Acute herniation of the heart into the operative
hemithorax can occur through the pericardial defect that is left
following a radical pneumonectomy.
- Nitrous oxide is contraindicated in patients
with cysts or bullae because it can expand the air space and cause
rupture. The latter may be signaled by sudden hypotension, bronchospasm,
or an abrupt rise in peak inflation pressure and requires immediate
placement of a chest tube.
- Following transplantation, peak inspiratory pressures
should be maintained at the minimum pressure compatible with good
lung expansion, and the inspired oxygen concentration should be maintained
at < 60%.
- Regardless of the procedure, the major anesthetic
consideration for patients with esophageal disease is the risk of
- During the transhiatal approach to esophagectomy,
substernal and diaphragmatic retractors can interfere with cardiac
Indications and techniques for thoracic surgery have continually
evolved since its origins. Common indications are no longer restricted
to complications of tuberculosis and suppurative pneumonitis but
now include thoracic malignancies (mainly of the lungs and esophagus),
chest trauma, esophageal disease, and mediastinal tumors. Diagnostic
procedures such as bronchoscopy, mediastinoscopy, and open-lung
biopsies are also common. Anesthetic techniques for separating the ventilation
to each lung have allowed the refinement of surgical techniques
to the point that many procedures are increasingly performed thoracoscopically.
High-frequency jet ventilation and cardiopulmonary bypass (CPB)
now allow complex procedures such as tracheal resection and lung transplantation,
respectively, to be performed. Anesthetic management of cardiac
surgery and anesthesia for thoracic aortic aneurysms are discussed
in Chapter 21; anesthesia for thoracic trauma
is reviewed in Chapter 41.
Thoracic surgery presents a unique set of physiological problems
for the anesthesiologist that requires special consideration. These
include physiological derangements caused by placing the patient
with one side down (lateral decubitus position), opening the chest (open pneumothorax), and
the frequent need for one-lung ventilation.
The lateral decubitus position provides optimal access for most
operations on the lungs, pleura, esophagus, the great vessels, other
mediastinal structures, and vertebrae. Unfortunately, this position
may significantly alter the normal pulmonary ventilation/perfusion
relationships (see Chapter 22). These derangements
are further accentuated by induction of anesthesia, ...