Preoperative Optimization of the Asthmatic Patient

Abstract

Introduction. 

            Asthma is a common upper respiratory condition among patients across the developmental spectrum. The condition is estimated to affect over 300 million people worldwide with prevalence rate and condition severity continually increasing.¹ With such a high prevalence rate worldwide, it is common to encounter asthmatic patients in need of elective surgery.¹ Bronchospasm is a common pathophysiologic feature of asthma. During a bronchospasm, the smooth muscle of the airway contracts and narrows the diameter of the airway.¹ As a result, a significant impedance to airflow can result. The obstruction to airflow makes ventilation difficult if not impossible. Patients who experience intraoperative bronchospasm are at increased risk for postoperative morbidity and mortality.¹ Given the severe implications of intraoperative bronchospasm, the anesthetic care of the asthmatic patient should focus on preoperative assessment and optimization in order to mitigate the risk of intraoperative bronchospasm and postoperative pulmonary complications. The purpose of pursuing this topic is to educate anesthesia providers about the complications resulting from intraoperative bronchospasm and to provide guidelines for preventing bronchospasm during the surgical period.

Case presentation. 

            A recent case of intraoperative bronchospasm involved a 77-year-old, female, ASA 4 inpatient. The patient had significant medical history including asthma and COPD. The scheduled procedure was a closed reduction of the left hip with percutaneous pinning. During the preoperative assessment the patient was identified, the planned procedure and surgeon were confirmed, all allergies and medications were reviewed, medical and anesthetic history were reviewed, and a physical exam was conducted. During the preoperative interview the patient confirmed a history of reactive airway disease, but reported that her asthma was well-controlled with current medications and denied any recent exacerbations. The patient did not receive any preoperative medications other than analgesics for pain control. The patient was taken to the operating room for surgery and was preoxygenated prior to anesthetic induction. The patient was induced with IV propofol, fentanyl, and lidocaine. Succinylcholine was subsequently administered to achieve optimal conditions for intubation. The patient was successfully endotracheally intubated and sevoflurane administered for anesthetic maintenance. Prior to incision, the ventilator alarms were triggered by high peak pressures and low tidal volumes. Manual ventilation was initiated, but was found to be difficult, leading to a progressive oxygen desaturation. As bronchospasm was suspected, albuterol was administered endotracheally. The patient responded well to the bronchodilator, ventilation became easier, and the oxygen saturation improved. Once the patient was stabilized, the hip surgery continued without further incident. However, at the conclusion of the surgery and just prior to emergence, the patient experienced another severe bronchospasm. Again, albuterol and epinephrine treatment were initiated until the patient respiratory status stabilized again. The patient remained intubated and was transferred to ICU to allow for further pulmonary stabilization prior to extubating.

Discussion. 

            A literature review was conducted on the anesthetic management of the asthmatic patient undergoing surgery. The current literature emphasizes the importance of comprehensive assessment and pharmacologic optimization of the asthmatic patient during the preoperative period as the most efficacious method for reducing poor post-operative pulmonary outcomes. Bronchodilatory beta 2 adrenergic agents such as albuterol or salbutamol effectively reduce the incidence of intraoperative bronchospasm. The findings suggest that the intraoperative problems related to bronchospasm encountered in the presented case may have been avoidable.

            As discussed, the prevalence of asthma is significant among surgical patients. With a high number of asthmatic patients receiving general anesthesia for surgery, prevention of intraoperative bronchospasm is important for improving outcomes among this patient population. Based on the current literature, the recommendation for practice would be to preoperatively treat all asthmatic patients, regardless of the perceived severity of their asthma, with a bronchodilatory agent prior to surgery in an effort to reduce the incidence of intraoperative bronchospasm.

            Future research on the topic should consider the costs associated with added length of hospital stay and additional treatment following an intraoperative bronchospasm. Prevention of an asthma exacerbation during the preoperative period is likely the most cost-effective approach to managing a patient with reactive airway disease.

Keywords

Bronchodilators, bronchospasm, asthma, optimization