By W. Lester. William Jewell College.
The somatic arteries anastomose on the posterior surface of the ver- tebral body purchase noroxin 400mg line, making a characteristic hexagon or diamond-shaped net- work on anterior–posterior angiography (Figures 1 discount 400mg noroxin with amex. Usually a hemivertebral blush is seen from one segmental arterial injection; this effect is evident only 25% of the time. The right intercostal artery will opacify the right hemivertebra and the ventral half of the left hemivertebra. Spinal Venous Anatomy We will approach the description of the venous anatomy of the spinal cord from the inside out. Venous drainage of the cord is divided into an intrinsic system (in proximity to the centrifugal arterial system but, nat- urally, with an opposite direction of flow) and the extrinsic system (in proximity to the centripetal arterial system). In general, the ventral dom- inance of the arterial system is not seen in the venous system. The venous drainage of the cord is relatively equally divided dorsally and ventrally. The intrinsic venous system comprises dorsal and ventral sulcal (sul- cocommissural) veins that collect the venous outflow from the central gray matter. Retrocorporeal hexagonal anastomosis of dorsal somatic branches to the vertebral body. The extrinsic venous system can be thought of as containing the ve- nous perforators draining into the radial/coronal veins, which in turn drain into the primary dorsal and ventral longitudinal collecting veins. These longitudinal collecting veins in turn drain into the radicular veins (analogous to the radiculomedullary and radiculopial veins), which even- tually empty into the ventral epidural venous plexus. In addition to the main dorsal and ventral draining veins, there are short intersegmental lateral longitudinal veins linking adjacent radial veins. These lateral lon- gitudinal channels are not large enough, however, to form a functional dominant craniocaudal channel like the dorsal and ventral systems.
An interrupted time series comparison-group design was used to as- sess the effects of the low back pain guideline demonstration buy 400mg noroxin with mastercard. Quar- xx Evaluation of the Low Back Pain Practice Guideline Implementation terly administrative data on service utilization and medication pre- scriptions were collected for low back pain patients served by the demonstration and comparison (control) sites buy discount noroxin 400mg, which provided trend information both before and after introduction of the guideline in the Great Plains Region. The comparison group allowed us to control for temporal trends that might account for changes in the indicators. The measures were appropriate choices for this demonstration because most of the participating MTFs focused their implementation actions on service delivery for acute low back pain (rather than chronic low back pain). The patient population for this study was limited to active duty Army personnel who received care for acute low back pain at one of the demonstration or comparison sites during the time period of the study. This design was selected because we could not obtain com- plete pharmaceutical data for all patients using these MTFs. The pharmacy data constraint was important because use of pain medi- cations is a major aspect of care for acute low back pain patients, and one-half of the indicators selected for the study are measures of pain medication use. Because acute low back pain is one of the major causes of lost duty days for active duty personnel, this study provides useful information even though it is limited to this population. We encourage expansion of the analysis to also include family members and retirees as other service utilization and pharmaceutical data be- come available. KEY FINDINGS FROM THE DEMONSTRATION This first demonstration to field test methods for implementation of clinical practice guidelines yielded rich insights even as the MTFs struggled to achieve lasting new practices. The performance of the demonstration and control MTFs on the six hypotheses for acute low back pain care (listed in the previous section of this summary) varied significantly at baseline (the six-month period before MTFs started working with the guideline). Introducing the guideline had few mea- surable effects related to those hypotheses. Despite these weak find- ings, the demonstration made a considerable contribution to im- Summary xxi provements in methods for subsequent guideline demonstrations, and ultimately, for implementation of the low back pain guideline in all Army health facilities as of January 2000. Two of the six critical success factors (see the previous section) emerged as the most important issues for the demonstration with re- spect to the limited success of the participating MTFs in improving low back pain care practices. Serious progress in practice improve- ment cannot happen without (1) having fully committed leadership at all levels and (2) establishing a credible monitoring and reporting system to provide accountability for desired improvements. The re- maining four critical success factors contribute to the effectiveness and timeliness of actions, but they are not expected to support ex- tensive progress in change if the leadership and monitoring are not in place.