Patients receiving no sedation were grouped together with those receiving care from the sedation nurses because “no sedation” was another alternative to the anesthesia providers. The intent of this competition analysis was to study the influence of alternatives to anesthesia providers on the utilization of anesthesia providers.
Over 12 yr, the annual increase in the number of pediatric imaging studies was 8.1% (Fig. 1, 95% CI: 6.8%–9.4%, MRI 7.8% and CT 8.2%, P < 0.0001). Anesthesia care for pediatric patients for MRI and CT increased 8.5% per year (95% CI: 6.3%–10.6%, P < 0.0001). The percentage of procedures performed with anesthesia providers was unchanged (+0.1% per year, 95% CI: −0.2% to +0.3% per year, P = 0.59). Mean anesthesia time per elective case was also unchanged (−1.0 min per case per year, 95% CI: −3.4 to 1.4 min, P = 0.38).
Anesthesia providers were rarely used for elective scans shorter than 30 min in duration (P < 0.0001 for all age groups) (Fig. 2). Only 3.3% (95% CI: 2.0%–5.0%) of patients undergoing brief scans received care from anesthesia providers. The percentage of children receiving anesthesia care was much greater for MRI than CT (Table 2). Increases in scan duration were associated with increased utilization of anesthesia providers after stratifying by age (P < 10−5 for MRI, for CT, and for the two combined). Children 3–5 yr of age had the highest rates of anesthesia care (Table 2).
There was minimal competitive effect of sedation nurses and/or no sedation for brief scans on the overall number of scans involving anesthesia providers (Fig. 3, overall 5%, 95% CI: 2%–11%). This analysis shows that alternatives to anesthesia care for brief scans had little to no effect on this anesthesia department’s workload for pediatric diagnostic radiology.
Over the 6-mo period studied, involvement of the sedation nurses increased from 0% to 14% of all imaging studies (P < 0.0001). However, the availability of the sedation nurses did not reduce the workload of anesthesia providers (−0.9%, 95% CI: −8.6% to +6.7%, P = 0.52). Most nurse sedation cases involved brief scans (59%, 95% CI: 49%–69%) and the competitive effect was not substantive. The total number of children who received some type of hypnotic became greater, and the percentage of children who received no sedation was reduced (−8.1%, 95% CI: −16.0% to −0.1%, P = 0.017).
The number of pediatric MRI and CT studies at the medical center under study increased by approximately 8% per year over the past 12 yr. Although the rate of growth may seem high, it is less than that reported for Medicare patients.11 The increase in anesthesia workload for these imaging studies was entirely consistent with the increase in the number of studies. The percentage of children receiving anesthesia services for imaging was unchanged.
To plan for future needs, anesthesia groups in the United States should be aware of changing patterns in imaging. Rates may not increase as they have in the past. Requirements for insurance preauthorization have resulted in declines in use of MRI and CT.22,23 Lower reimbursements to radiologists may reduce the availability of personnel and/or restrict scanner time.24 In contrast, technological changes that increase scan times may boost demand for anesthesia providers, whereas changes that reduce the noise and claustrophobia of MRI scanners may reduce future workload. Concern over radiation exposure may favor use of MRI over CT,25 resulting in longer average scan times (Table 2). The importance of scan duration and age in determining the need for anesthesia providers should be recognized when forecasting anesthesia staffing.
The use of anesthesia providers for imaging in the United States may also be influenced by reimbursement patterns. Treatment of dental caries in children rose substantially when health insurance plans were required to cover the costs of general anesthesia.26 Increasing numbers of anesthesiologists are providing services for gastrointestinal endoscopies,27,28 but the number of cases performed depends on the payment policies of local insurance carriers.27 Scans of short duration may be particularly susceptible to limited or no reimbursement because of greater difficulty in demonstrating medical necessity for anesthesia services. Problems may also arise if insurance companies cover anesthesia for longer scans but not shorter ones, and use CPT codes as a basis for preauthorization decisions. CPT codes reflect the organs imaged and the workload of radiologists. CPT codes are frequently not reliable predictors of scanner times.6 Although some codes are generally associated with brief scans,6 such as a CT of the head, other codes, such as an MRI of the brain, are not necessarily indicative of scan duration for an individual patient. Furthermore, given the exceedingly large number of combinations of codes that can comprise a single procedure, uncertainty in predicting scan duration is high if only CPT codes are used.6
Creation of a nurse sedation program at this hospital did not cannibalize the anesthesia department’s business. It merely increased the number of children receiving hypnotics. This result differs from that of hospitals where most sedation was initially being administered by personnel with limited training in pediatric sedation.29 Anesthesiologists were often needed to rescue failed sedations and were thought to increase scan quality.30,31 When sedation nurses are used in lieu of radiologists with less experience in sedation, the nurses may decrease use of anesthesiologists.
Regardless of other factors, anesthesia providers will likely continue to provide sedation and/or general anesthesia for pediatric diagnostic radiology at our institution. Anesthesia providers are needed for children with known or suspected airway problems. General anesthesia may improve image quality when sedation is insufficient to prevent an uncooperative child from moving.
We do not know whether the consistency over time in the percentage of children receiving anesthesia care is universal, or whether other institutions would report different findings. Few facilities have sufficient historical data to perform such analyses. The specific results obtained for this hospital regarding the sedation nurses are likely not applicable to other institutions. Our results reflect the well-established role of anesthesia providers arising from their guaranteed availability3,5 in providing services for pediatric diagnostic imaging.
However, the findings regarding age and scan length, and the principles associated with changes in MRI usage and reimbursement for anesthesia care, are appropriate for consideration by anesthesia groups nationwide to aid in planning future workload.
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