IN this issue of the Journal, Silvanus et al.  studied the effects of preoperative interventions in patients with reversible airway obstruction (RAO). 1This article raises the question of when corticosteroids may be useful to prevent an adverse perioperative outcome for the patient with RAO.

The low frequency of adverse outcomes in anesthesia practice limits the ability of researchers to conduct prospective randomized controlled trials to identify best practices. This is certainly the case for adverse outcomes linked to reactive airways disease and anesthesia. Warner et al.  looked at the population of patients with asthma who underwent surgery in Olmstead County, Minnesota, and found the incidence of adverse outcomes to be very low. 2On the other hand, we know from the American Society of Anesthesiologists Closed Claims study that severe bronchospasm occasionally leads to brain damage or death. 3Furthermore, the present author has repeatedly informally surveyed the audience at his American Society of Anesthesiologists refresher course on bronchospasm as to whether they had ever cared for a patient with what they believed was life-threatening bronchospasm under anesthesia. Although the results are certainly biased (because clinicians probably tend to go to a lecture on the topic after such an event), many audience members raise a hand in response to the question. Hence, severe bronchospasm seems to be a serious complication of low but finite incidence.

Because of this low incidence of severe adverse outcomes, researchers interested in bronchospasm have tended to study the more common but less serious surrogate outcomes of increased respiratory resistance or audible wheezing. 4,5Audible wheezing occurred in 4% of patients intubated following an induction dose of thiopental, and reversible bronchoconstriction following intubation is probably the rule rather than the exception when assessed by respiratory resistance. 4,6Bronchospasm severe enough to require treatment probably occurs in the range of 1 in 250 patients anesthetized but is probably more prevalent in some populations with a high frequency of lung disease. We do not know, however, whether these phenomena can be linked to the rare severe outcome attributed to bronchospasm. Despite the absence of that link, it does seem reasonable to assume that reducing the incidence of mild bronchospasm is a useful goal.

This Editorial View accompanies the following article: Silvanus M-T, Groeben H, Peters J: Corticosteroids and inhaled salbutamol in patients with reversible airway obstruction markedly decrease the incidence of bronchospasm after endotracheal intubation. Anesthesiology 2004; 100:1052–7.

Silvanus et al.  studied patients who were scheduled for surgery and who were found to have RAO during pre-operative assessment. Only patients who had RAO and were not currently receiving treatment were studied. The patients tended to fit the criteria for chronic obstructive pulmonary disease to a greater extent than for asthma, as they had some evidence of limited vital capacity and their forced expiratory volume in 1 s appeared to reverse only moderately with treatment. The patients were divided into three groups: those who received no treatment other than albuterol just before induction and intubation, those who received 5 days of albuterol prior to intubation, and those who received 5 days of corticosteroid plus albuterol prior to intubation. The group receiving steroids had a much lower incidence of wheezing than did the other two groups.

Should we be surprised that albuterol alone, while improving the forced expiratory volume in 1 s, did not prevent intubation-induced bronchoconstriction? Probably not. Patients may show marked improvement following albuterol when their airways are not provoked. However, the mechanical stimulus of intubation is a powerful provocation for bronchoconstriction that may unmask ongoing disease. This is probably analogous to a methacholine provocation test: a patient may have a normal forced expiratory volume in 1 s but still react to a stimulus.

Does this study differ from previous studies documenting that albuterol alone markedly limits intubation-induced bronchoconstriction? Not really, because those studies were in unselected patients, whereas these patients had significant preexisting disease. Rather, this article suggests that in patients with documented reversible disease, it may be best to provide therapy beyond a beta agonist alone.

How should this article affect our practice? We probably don’t see many patients with untreated disease as severe as these patients had. The mean forced expiratory volume in 1 s/forced vital capacity ratio of 55% seen in this study would generally be enough to bring someone to medical attention and treatment. Given a reversible component of airway obstruction, the National Heart Lung and Blood Institute Expert Panel on Asthma supports the use of antiinflammatory therapy. 7Hence, most patients with this degree of illness will likely already be receiving inhaled steroids. If they are not, this article certainly supports the benefits of adding a short course of oral corticosteroids preoperatively. Even if they are receiving inhaled steroids but have ongoing symptoms, a brief trial of steroids may be warranted.

Should every patient with a history of reactive airways receive such treatment? Not even close. The incidence of wheezing at some point in life is very high. A recent study from New Zealand (admittedly a country with one of the highest rates of wheezing) found that over 50% of individuals followed from birth to 26 yr of age complained of wheezing at some point, and 14.5% continued to have occasional symptoms. 8An 8% incidence for asthma is often cited in the U.S. population. To test all of those individuals preoperatively and to give them a steroid bolus would be a large and unnecessary undertaking.

Which patients should we consider for steroid treatment? As always, the highest-risk patients: those about to undergo abdominal or thoracic surgery, who will be at greatest risk for postoperative pulmonary complications, and those with the worst pulmonary function preoperatively. To some extent, the assessment of preoperative pulmonary function must be based on clinical assessment, because we are unlikely to routinely perform preoperative pulmonary function tests in all patients.

In being realistic, we must recognize that the scheduled procedure may drive how aggressive we are with preoperative steroid treatment. A patient scheduled for an upper abdominal procedure with a high risk of pulmonary complications must be treated with the utmost caution. On the other hand, a patient scheduled for a knee arthroscopy or a foot procedure who has evidence of mild-to-moderate disease and is not under absolutely optimal treatment for RAO may still safely undergo the procedure, given our access to local and regional anesthetics and laryngeal masks. A real-life example: the Alaskan bush resident who arrives at the Puget Sound Veterans Hospital 2,000 miles from home for a foot reconstruction and has wheezing on preoperative examination will probably receive albuterol and a spinal or regional anesthetic rather than preoperative steroids. On the other hand, if this patient were scheduled for a thoracotomy, the case would probably be postponed pending steroid treatment.

We should also recognize that this study probably overstates the risks of postintubation wheezing in that the trachea was intubated following thiopental induction. There is ample evidence that propofol prevents postintubation wheezing and bronchoconstriction, 4,5and few of us currently would use thiopental as our induction agent for these patients. Also, if appropriate for the planned procedure, we would probably opt for a laryngeal mask airway, which does not provoke bronchoconstriction. 9 

Are there any reasons not to treat patients aggressively with corticosteroids? Brief courses of corticosteroids do not seem to be associated with significant effects on wound healing or infection. 10However, a preoperative course can delay surgery, and many patients find high doses of steroids somewhat unpleasant. Thus, for most patients with RAO, a steroid course is unnecessary.

Where does that leave us? This article provides data to support an already existing recommendation, that of the National Heart Lung and Blood Institute Expert Panel, which recommended that before surgery, the clinician review symptoms, medication use, and measurements of pulmonary function and that attempts should be made to improve lung function to a personal best. The monograph goes on to note that this may occasionally require a short course of steroids. Silvanus et al.  have provided us with data to support the beneficial effects of steroids on wheezing during the perioperative period. Whether this truly affects adverse outcomes may require a study that would be logistically very difficult to perform.

Silvanus M-T, Groeben H, Peters J: Corticosteroids and inhaled salbutamol in patients with reversible airway obstruction markedly decrease the incidence of bronchospasm after endotracheal intubation. Anesthesiology 2004; 100:1052–7
Warner DO, Warner MA, Barnes RD, Offord KP, Schrieder DR, Gray DT, Yunginger JW: Perioperative respiratory complications in patients with asthma. Anesthesiology 1996; 85:459 –67
Cheney FW, Posner KL, Caplan RA: Adverse respiratory events infrequently leading to malpractice suits. Anesthesiology 1991; 75:932–9
Pizov R, Brown RH, Weiss YS, Baranov D, Hennes H, Baker S, Hurshman CA: Wheezing during induction of general anesthesia in patients with and without asthma: A randomized, blinded trial. Anesthesiology 1995; 82:1111–6
Eames WO, Rooke GA, Wu RS, Bishop MJ: Comparison of the effects of etomidate, propofol, and thiopental on respiratory resistance following tracheal intubation. Anesthesiology 1996; 84:1307–11
Kil HK, Rooke GA, Ryan-Dykes MA, Bishop, MJ: Effect of prophylactic bronchodilator treatment on lung resistance after tracheal intubation. Anesthesiology 1994; 81:43–8
Sears MR, Greene JM, Willan AR, Wiecek EM, Taylor DR, Flannery EM, Cowan JO, Herbison GP, Silva PA, Poulton R: A longitudinal, population-based, cohort study of childhood asthma followed to adulthood. N Engl J Med 2003; 349:1414 –22
National Institutes of Health Guidelines for the diagnosis and management of asthma: Clinical Practice Guidelines Expert Panel Report 2. Bethesda, Maryland, National Institutes of Health, 1997
Kim ES, Bishop MJ: Endotracheal intubation, but not laryngeal mask airway insertion, produces reversible bronchoconstriction. Anesthesiology 1999; 90: 391–4
Kabalin CS, Yarnokld PR, Grammer LC: Low complication rate of corticosteroid-treated asthmatics undergoing surgical procedures. Arch Intern Med 1995; 155:1379 –84