Articles from Anesthesia and Analgesia

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Wachtel, Ruth E. ; Dexter, Franklin ; Dow, Angella J.
Growth Rates in Pediatric Diagnostic Imaging and Sedation
Anesthesia & Analgesia. 108(5):1616-1621, May 2009.
Abstract
BACKGROUND: Workload has increased greatly over the past decade for anesthesia providers administering general anesthesia and/or sedation for pediatric diagnostic imaging.METHODS: Data from an academic medical center were studied over a 12-yr period. Growth in the number of children 0-17 yr of age undergoing magnetic resonance imaging (MRI) and/or computerized tomography (CT) scans who received care from anesthesia providers was compared with the increase in the total number of MRI and CT procedures performed in children. Anesthesia providers included anesthesiologists, residents, Certified Registered Nurse Anesthetists, and student Certified Registered Nurse Anesthetists. Toward the end of the study, a team of sedation nurses was employed by the hospital to administer moderate sedation. They provided an alternative to anesthesia providers from the anesthesia department, who usually administered general anesthesia. Use of sedation nurses versus anesthesia providers, and the relationship to scan duration and patient age, were studied over a 6-mo period.RESULTS: The number of children receiving care from anesthesia providers for MRI and CT scans grew at the same 8%-9% annual rate as the number of scans performed. The percentage of children receiving anesthesia care did not change over the 12 yr. Creation of a nurse sedation team that provided moderate sedation did not alter the number of children receiving care from anesthesia providers but did increase the total number of children receiving hypnotics. Anesthesia was rarely used for scans shorter than 30 min in duration. Increases in scan duration were associated with increased utilization of anesthesia providers for both MRI and CT after stratifying by age. An age of 3-5 yr was associated with the highest rates of anesthesia care.CONCLUSIONS: Future workload for anesthesia providers administering general anesthesia and/or sedation for pediatric diagnostic imaging will depend on trends in the total number of scans performed. Workload may also be sensitive to factors that increase scan duration or alter the percentage of patients in the 3-5 yr age group. It may additionally depend on reimbursements from insurance companies.

Gadhinglajkar, Shrinivas ; Sreedhar, Rupa
Surgery for Anomalous Origin of Left Coronary Artery From Pulmonary Artery: The Utility of Intraoperative Transesophageal Echocardiography.
Anesthesia & Analgesia. 108(5):1470-1472, May 2009.


Yang, Ping-Liang ; Wong, David T. ; Dai, Shuang-Bo ; Song, Hai-Bo
The Feasibility of Measuring Renal Blood Flow Using Transesophageal Echocardiography in Patients Undergoing Cardiac Surgery. [Review]
Anesthesia & Analgesia. 108(5):1418-1424, May 2009.
Abstract
BACKGROUND: There is no reliable method to monitor renal blood flow intraoperatively. In this study, we evaluated the feasibility and reproducibility of left renal blood flow measurements using transesophageal echocardiography during cardiac surgery.METHODS: In this prospective noninterventional study, left renal blood flow was measured with transesophageal echocardiography during three time points (pre-, intra-, and postcardiopulmonary bypass) in 60 patients undergoing cardiac surgery. Sonograms from 6 subjects were interpreted by 2 blinded independent assessors at the time of acquisition and 6 mo later. Interobserver and intraobserver reproducibility were quantified by calculating variability and intraclass correlation coefficients.RESULTS: Patients with Doppler angles of >30[degrees] (20 of 60 subjects) were eliminated from renal blood flow measurements. Left renal blood flow was successfully measured and analyzed in 36 of 60 (60%) subjects. Both interobserver and intraobserver variability were <10%.>

Articles from Anesthesiology

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Practice Advisory on Anesthetic Care for Magnetic Resonance Imaging: A Report by the American Society of Anesthesiologists Task Force on Anesthetic Care for Magnetic Resonance Imaging
Anesthesiology. 110(3):459-479, March 2009.

Article from Anesthesia & Analgesia

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Clendenen, Steven R. ; Riutort, Kevin ; Ladlie, Beth L. ; Robards, Christopher M. et al
Real-Time Three-Dimensional Ultrasound-Assisted Axillary Plexus Block Defines Soft Tissue Planes. [Report]
Anesthesia & Analgesia. 108(4):1347-1350, April 2009.
Abstract
Two-dimensional (2D) ultrasound is commonly used for regional block of the axillary brachial plexus. In this technical case report, we described a real-time three-dimensional (3D) ultrasound-guided axillary block. The difference between 2D and 3D ultrasound is similar to the difference between plain radiograph and computer tomography. Unlike 2D ultrasound that captures a planar image, 3D ultrasound technology acquires a 3D volume of information that enables multiple planes of view by manipulating the image without movement of the ultrasound probe. Observation of the brachial plexus in cross-section demonstrated distinct linear hyperechoic tissue structures (loose connective tissue) that initially inhibited the flow of the local anesthesia. After completion of the injection, we were able to visualize the influence of arterial pulsation on the spread of the local anesthesia. Possible advantages of this novel technology over current 2D methods are wider image volume and the capability to manipulate the planes of the image without moving the probe.

Maintenance of Anesthesia in Children Undergoing Magnetic Resonance Imaging

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Heard, Christopher ; Burrows, Frederick ; Johnson, Kristin ; Joshi, Prashant et al
A Comparison of Dexmedetomidine-Midazolam with Propofol for Maintenance of Anesthesia in Children Undergoing Magnetic Resonance Imaging
Anesthesia & Analgesia. 107(6):1832-1839, December 2008.
Abstract
BACKGROUND: Dexmedetomidine is an [alpha]2 agonist that is currently being investigated for its suitability to provide anesthesia for children. We compared the pharmacodynamic responses to dexmedetomidine-midazolam and propofol in children anesthetized with sevoflurane undergoing magnetic resonance imaging (MRI).
METHODS: Forty ASA 1 or 2 children, 1-10 yr of age, were randomized to receive either dexmedetomidine-midazolam or propofol for maintenance of anesthesia for MRI after a sevoflurane induction. Dexmedetomidine was administered as an initial loading dose (1 [mu]g/kg) followed by a continuous infusion (0.5 [mu]g [middle dot] kg-1 [middle dot] h-1). Midazolam (0.1 mg/kg) was administered IV when the infusion commenced. Propofol was administered as a continuous infusion (250-300 [mu]g [middle dot] kg-1 [middle dot] min-1). Recovery times and hemodynamic responses were recorded by one nurse who was blinded to the treatments.
RESULTS: We found that the times to fully recover and to discharge from the ambulatory unit after dexmedetomidine administration were significantly greater (by 15 min) than those after propofol. Analysis of variance demonstrated that heart rate was slower and systolic blood pressure was greater with dexmedetomidine than propofol. Respiratory indices for the two treatments were similar. During recovery, hemodynamic responses were similar. Cardiorespiratory indices during anesthesia and recovery remained within normal limits for the children's ages. No adverse events were recorded.
CONCLUSION: Dexmedetomidine-midazolam provides adequate anesthesia for MRI although recovery is prolonged when compared with propofol. Heart rate was slower and systolic blood pressure was greater with dexmedetomidine when compared with propofol. Respiratory indices were similar for the two treatments.