••• CHAPTER 34^ Preoperative Evaluation and Preparation of Gynecologic Surgery^345
❍ What is the greatest risk factor for the development of postoperative pulmonary complications?
Chronic obstructive pulmonary disease (COPD).
❍ What is obstructive lung disease?
A category of lung diseases that causes a reduction and prolongation of air flow during expiration.
❍ What are the three most common COPDs?
Chronic bronchitis, emphysema, and asthma.
❍ What is restrictive lung disease?
A category of disorders that limit lung expansion resulting in a decreased lung volume and increased work of
breathing. This may be the result of either intrinsic pathology (such as pulmonary fibrosis or ARDS) or an extrinsic
pathology (such as chest wall deformities, neuromuscular disorders, or diseases of the abdominal cavity that lower
the thoracic volume).
❍ What is considered a normal forced expiration?
Forced expiratory volume (FEV) in 1 second should be >75% of the predicted normal volume.
❍ What does high PCO 2 represent?
Usually hypoventilation.
❍ What does low PaO 2 represent?
Ventilation-perfusion mismatch, diffusion defect, or anatomical shunting.
❍ What is a confirmation that anatomical shunting is the cause of hypoxemia?
By the inability to raise the PaO 2 above 55 mm Hg after breathing 100% oxygen for 30 minutes.
❍ What factor predisposes patients with COPD to postoperative pneumonia and atelectasis?
The impaired ability for effective cough and clearance of secretions.
❍ What preoperative arterial blood gas findings are associated with postoperative pulmonary complications?
PaO 2 values <70 mm Hg, and PaCO 2 values >45 mm Hg.
❍ What preoperative measures for patients with COPD help to minimize postoperative pulmonary
complications?
Chest physiotherapy, bronchodilators, and antibiotics for patients with positive sputum cultures.
❍ What FEV 1 value is correlated with postoperative pulmonary complications?
An FEV1 value of <1 L.
❍ When should preoperative chest radiographs be performed?
Age over 60; a history of smoking, pulmonary disease, surgery for malignancy to exclude pulmonary metastases,
and patients who present with cardiac or pulmonary signs or symptoms.