What preoperative evaluation and preparation would you order for this patient?

What preoperative evaluation and preparation would you order for this patient? Would you cancel the case if the patient said that she was just recovering from a “bad cold” and had a few scattered wheezes on auscultation? Would you continue the aminophylline during the perioperative period?

History and physical examination are the first step. Important information to elicit is the frequency and severity of attacks, the response to treatment, the need for emer-gency room visits, hospital admissions and mechanical ventilation, and the use of systemic steroids (dose, dura-tion, last use). If the patient uses a peak expiratory flow (PEF) device, the best PEF and the current value should be obtained. There is probably no benefit in obtaining pre-operative PFTs for a patient with asthma. Although the importance of the presence of wheezing on physical exam-ination is often discussed, it should be noted that severe bronchospasm often manifests as almost absent breath sounds with little to no wheezing.

Patients with mild asthma do not need any special test-ing or preparation. Oral medications such as cromolyn, leukotriene inhibitors, and steroids should be continued until the day of surgery. The patient should use their MDI β₂-agonist before entering the operating room because this has been shown to decrease the incidence of intra-operative bronchospasm. As appropriate, infection should be eradicated with antibiotics; chest physiotherapy should be used to improve bronchial drainage; and cessation of smoking should be maintained for at least 2 months to restore ciliary function and decrease mucus production. Cessation of smoking for 12–48 hours preoperatively decreases carboxyhemoglobin concentrations but has been shown to increase mucus production and possibly lead to an increased incidence of postoperative pulmonary complications.

The 1991 National Institutes of Health (NIH) expert panel recommended that asthmatics with an FEV₁ <80% of predicted receive a preoperative course of oral steroids. This has been shown to decrease perioperative pulmonary complications. Wound healing and infection is not affected by a short course of steroids. Treatment should be initiated 24–48 hours before surgery and can consist of 40–60 mg of prednisone per os once a day or 100 mg of hydrocortisone intravenously (IV) 8-hourly. This should be continued for 1 or 2 days after surgery and can usually be discontinued without tapering.

A history of recent airway viral infection increases airway reactivity in normal patients, and is one of the main triggers for exacerbations. In the adult patient with a clear chest auscultation, it is probably safe to proceed. Whether an elective case should be delayed in a sympto-matic patient is controversial and no clear cut-off point can be given beyond which the risks justify the inconven-ience. Response to treatment with inhaled β₂-agonists and steroids might help in determining the risk. A small child, on the other hand, would have more severe bronchospasm with the same trigger, because the airway diameter is smaller. Therefore, an elective case should be delayed for a few weeks. A recent study confirmed the increased inci-dence of adverse respiratory events in children with upper respiratory infections, but no long-term sequelae were noted.

If there are no signs of toxicity, such as tachycardia, tremulousness, nausea or vomiting, aminophylline should be continued during the perioperative period, with drug levels checked as indicated.