2. Preoperative assessment
Most patients are older and have a long history of tobacco and alcohol abuse. Associated medical problems may include COPD, hypertension, coronary artery disease, and alcohol withdrawal.
a) History and physical examination: Individualized
(1) Respiratory: Smoking (more than 40 packs/year) is associated with bronchitis, pulmonary emphysema, and COPD, which impair respiratory function. Arterial blood gases may reveal carbon dioxide retention and hypoxemia. Pulmonary function tests demonstrate decreased forced expiratory volume, forced vital capacity, and the ratio of forced expiratory volume to forced vital capacity. Preoperative airway assessment is imperative because edema may distort airway anatomy, and tumor and edema may cause airway compromise. Tracheal deviation must be considered. Fibrosis, edema, and scarring from prior radiation therapy may distort the airway as well.
(2) Assess for signs of alcohol withdrawal (altered mental status, tremulousness, and increased sympathetic activity).
(3) Gastrointestinal: Weight loss, malnutrition, dehydration, and electrolyte imbalance can be significant.
3. Patient preparation
a) Laboratory tests: Baseline arterial blood gases; electrolytes; hemoglobin; hematocrit; prothrombin time; partial thromboplastin time; and, if indicated from the history and physical examination, hepatic function tests are obtained.
b) Diagnostic tests: Chest radiography, ECG, pulmonary function testing, echocardiography, and stress tests are as indicated from the history and physical examination. Indirect and direct laryngoscopies preoperatively and review of CT may help in planning intubation.
c) Medications: Treatment with a long-acting hypnotic, such as chlordiazepoxide or diazepam, as a precaution for delirium tremens can be considered unless sedation would be contraindicated because of concerns of airway compromise. An IV antisialagogue (glycopyrrolate, 0.2 mg) facilitates endoscopy by the surgeon.