To the Editor:—
We read with interest the article by Hadzic et al. 1regarding the use of scalene regional anesthesia in rotator cuff surgery. Any prospective, randomized study on this topic is to be applauded, although Kinnard et al. 2also performed a prospective randomized study in 1994. We had a number of questions about the study of Hadzic et al. Rotator cuff repair can be performed with a variety of techniques, and the type of technique—arthroscopic, mini-open, or open—must be described in the method section, because randomization does not guarantee that equal numbers would be presented in each group. All arthroscopic rotator cuff repair in particular does not require any extraordinary efforts to manage perioperative pain and might have changed the results of this study. Clearly the physicians, nursing staff, and patients could not possibly have been blinded to the presence of a paralyzed, anesthetic extremity, and the study for this reason is not blinded. The term “light sleep” might be better defined, because some might define these patients as having both scalene and general anesthesia. The 16% rate of admission for general anesthesia for rotator cuff surgery is quite atypical and worrisome; in an outpatient center, any persistent rate of admission of more than 10% of patients would cause the facility to be disaccredited by the Joint Commission on Accreditation of Healthcare Organizations. The study clearly states that after discharge, there was no difference between the two techniques of any kind except for the patient choice to do the same technique again, a difficult decision for a patient who has had experience with only one of the two techniques.
Our greatest concern was over cost analysis and the discussion of complications. One of the most difficult sections of our article was the discussion of cost of general versus regional anesthesia.3In our institution, scalene regional anesthesia resulted in an increased cost of $1,507. The modest savings reported in this study generated by bypassing the phase 1 postanesthesia care unit would not offset this. In most outpatient centers, the phase 1 and phase 2 postanesthesia care unit patients would be commingled, with no savings generated at all. Serious complications remain the primary concern with scalene blocks. Although experience does decrease the rate of complications, it does not obviate them. One of the two neurologic injuries reported in our study occurred at a leading clinic with significant experience in regional anesthesia,3and the serious complication reported by Tetzlaff et al. 4occurred at Cleveland Clinic after a report of several hundred successful blocks. The authors freely admit that their study was underpowered to make a conclusion about a variety of outcomes of the study. Statistical analysis shows that their study would have required 103 patients in the block group to detect a 3.6% difference in their complication rate with a 95% confidence level. Because this is the difference in complication rates reported between their study and ours, their study is underpowered to make the conclusion that their complication rate is significantly different from ours as well.
The primary problem remains the rare but measurable rate of serious complications present in all large studies. Any single significant complication would offset the modest improvement in perioperative pain control. As recent lively discussions on this topic at the 2004 American Shoulder and Elbow Surgeons’ meeting (New York, New York, September 29, 2004 through October 02, 2004) can attest, this subject is far from closed.
*Sacramento Knee and Sports Medicine, Sacramento, California. webersc@earthlink.net
