Asthma and Special Considerations

Asthma and Surgery

Surgery may present several problems for asthmatics and must be approached carefully. To avoid complications there should be close communication prior to the procedure between the surgeon and the physician responsible for managing the patient's asthma.

Possible Complications

Complications may arise from several sources in patients with asthma who undergo surgery. When general anesthesia is required, the windpipe is intubated with a tube connected to a respirator. Under anesthesia, the respirator provides mechanical breathing and ensures the exchange of oxygen and carbon dioxide. In asthma patients, intubating the windpipe may trigger reflexes originating in the throat that can lead to bronchoconstriction. Therefore, alternatives to general anesthesia local, regional, and spinal should always be considered, depending greatly upon the type of surgery and the surgeon's preference.

Further complications may be caused by bronchoconstriction during and after surgery. Oxygen and carbon dioxide levels may be affected. Surgery is often a source of decreased depth of breathing; as a result the small air sacs of the lung may collapse, a condition known as atelectasis. This condition may also lower oxygen levels and, combined with the presence of bronchoconstriction, can produce an even greater drop in blood oxygen. More severe atelectasis can be expected in patients who undergo general anesthesia. Thick bronchial mucus of asthma may clog airways and increase the risk of lung infection.

Complications vary greatly depending on the surgery performed. The greatest risk occurs from procedures involving the chest, such as heart or lung operations. Surgery performed on the upper abdomen, such as gall bladder removal, may also impact lung function significantly.

How to Avoid Complications from Surgery

The Preoperative Evaluation

If surgery is needed, a preoperative evaluation should be performed by the primary physician, even in patients who are under good control, because complications may arise in any asthmatic patient. Patients with moderate to severe asthma are certainly at greater risk for complications and should have diligent preoperative checkups.

During evaluation the patient's history, medications, and flow rates or spirometry should be reviewed. The frequency of asthma attacks should be noted as well as the person's need for bronchodilator sprays and corticosteroids.

Allergies to medications and previous reactions to anesthesia should be noted at this time. The patient should be instructed on how to take asthma medication before surgery, since many procedures are now performed outpatient or the same day.