Anatomical, neurological and behavioural research has suggested differences between the brains of right- and non-right-handed individuals, including differences in brain structure, electroencephalogram patterns, explicit memory and sleep architecture. Some studies have also found decreased longevity in left-handed individuals. We therefore aimed to determine whether handedness independently affects the relationship between volatile anaesthetic concentration and the bispectral index, the incidence of definite or possible intra-operative awareness with explicit recall, or postoperative mortality. We studied 5585 patients in this secondary analysis of data collected in a multicentre clinical trial. There were 4992 (89.4%) right-handed and 593 (10.6%) non-right-handed patients. Handedness was not associated with (a) an alteration in anaesthetic sensitivity in terms of the relationship between the bispectral index and volatile anaesthetic concentration (estimated effect on the regression relationship -0.52 parallel shift; 95% CI -1.27 to 0.23, p = 0.17); (b) the incidence of intra-operative awareness with 26/4992 (0.52%) right-handed vs 1/593 (0.17%) non-right-handed (difference = 0.35%; 95% CI -0.45 to 0.63%; p = 0.35); or (c) postoperative mortality rates (90-day relative risk for non-right-handedness 1.19, 95% CI 0.76-1.86; p = 0.45). Thus, no change in anaesthetic management is indicated for non-right-handed patients.

We thank Drs. van Klei et al. and Qiu et al. for their kind comments about our report1and for insights into the potential benefits that preoperative visits to an anesthesia-directed clinic can have on operating room efficiency, patient safety, and hospital-wide cost savings. We strongly agree with their position that the use of these clinics should be expanded in efforts to extend these benefits.Dr. van Klei et al. noted that the impact of preoperative clinics on day-of-surgery case cancellations has already been reported. We suggest, however, that the data they cite do not represent contemporary practice as accurately as the data presented in our study. Specifically, their data2were gathered in a setting where almost all patients (92% even after the creation of their evaluation center) were still being admitted ahead of surgery. Furthermore, their average clinic visit occurred 3 weeks ahead of the scheduled operation. In contrast, none of the patients in our study were admitted ahead of surgery, and nearly all were seen within 2 weeks of their operation. Goals of a preoperative clinic and factors linking clinic efforts to cancellation rates may be different when the clinic visit is so removed in time. The other referenced study was Fisher’s landmark article describing the creation of a preoperative anesthesia clinic at Stanford.3The data on the impact of clinic visits on day-of-surgery cancellations in this study also differ from ours in that “an ‘informal assurance’ existed that, if a patient was evaluated … in the [clinic], the case would proceed to surgery without cancellation or delay.” This “informal assurance” made it very likely that the number of cancelled cases in that study had to decline. No such agreement existed in our report.Van Klei et al. also noted that our report did not identify the reasons why cases were cancelled, and that our cancellation rates were high. We agree that identifying the reasons for cancellation can significantly affect the interpretation and implementation of our results. Although these data were not available to us at the time of publication, we are currently pursuing this issue. With respect to why our cancellation rate was so high, we note that other studies4have shown cancellation rates identical to our overall 11% incidence. The lower results in the studies cited by van Klei et al. may reflect a focus on only “medical reasons” for cancellation and the concerns mentioned above (preadmission of patients and tacit guarantees of no cancellations). Finally, we agree with van Klei et al. that in a perfect world, all patients would be seen in an anesthesia preoperative medical clinic (APMC). This would almost certainly improve patient satisfaction and safety and improve operating room morale and efficiency. One important implication of our data was proof of the assertion that an APMC can improve operating room efficiency. We hope that these data will increase hospitals’ willingness to provide financial support for these endeavors. Nevertheless, until this financial support materializes, APMCs must make decisions about how best to use the available resources. To this point, our data argue that if we do not have the resources to see all patients in the APMC, emphasis should be placed on seeing the elderly and patients with significant comorbidities because the greatest impact of a clinic visit was seen in these groups.The data of Dr. Qiu et al. certainly validate our findings and demonstrate the usefulness of the APMC concept in nonuniversity settings as well. Furthermore, the discussion by Qiu et al. of the financial pressures and scrutiny that an APMC must overcome directly addresses the final question of van Klei et al. : Why can’t everyone be seen in an APMC? We believe it likely that in the United States, a compelling demonstration of societal cost savings must be demonstrated before any organization will help pay for the clinic. It was our purpose to document that an APMC can produce financial savings to the hospital and that the costs of the clinic should rationally be borne by all of the institutional members who benefit.*University of Chicago, Chicago, Illinois. dglick@dacc.uchicago.edu