Monday 8 June 2009

Articles from Anesthesia and Analgesia

Link to journal online
O'Connor, Maeve; Coleman, Margaret; Wallis, Fintan ; Harmon, Dominic
An Anatomical Study of the Parasacral Block Using Magnetic Resonance Imaging of Healthy Volunteers.
Anesthesia & Analgesia. 108(5):1708-1712, May 2009.
Abstract
BACKGROUND: The parasacral approach to sciatic blockade is reported to be easy to learn and perform, with a high success rate and few complications.METHODS: Using magnetic resonance imaging, we evaluated the accuracy of a simulated needle (perpendicular to skin) in contacting the sacral plexus with this approach in 10 volunteers. Intrapelvic structures encountered during the simulated parasacral blocks were also recorded.RESULTS: The sacral plexus was contacted by the simulated needle in 4 of the 10 volunteers, and the sciatic nerve itself in one volunteer. The plexus was accurately located adjacent to a variety of visceral structures, including small bowel, blood vessels, and ovary. In the remaining five volunteers (in whom the plexus was not contacted on first needle pass), small bowel, rectum, blood vessels, seminal vesicles, and bony structures were encountered. Historically, when plexus is not encountered, readjustment of the needle insertion point more caudally has been recommended. We found that such an adjustment resulted in simulated perforation of intrapelvic organs or the perianal fossa.CONCLUSIONS: These findings question the reliability of the anatomical landmarks of the parasacral block and raise the possibility of frequent visceral puncture using this technique.

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.

Garwood, Susan MB, ChB
Measuring Renal Blood Flow with the Intraoperative Transesophageal Echocardiography Probe.[Editorial]
Anesthesia & Analgesia. 108(5):1371-1376, May 2009.

Yang, Ping-Liang ; Wong, David T. ; Dai, Shuang-Bo ; Song, Hai-Bo et al
The Feasibility of Measuring Renal Blood Flow Using Transesophageal Echocardiography in Patients Undergoing Cardiac Surgery.
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%.>

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