A multi-center analysis evaluating factors associated with spinal cord stimulation outcome in chronic pain patients.

BACKGROUND: In addition to its conventional use as a treatment for refractory neuropathic extremity pain, spinal cord stimulation (SCS) has recently emerged as a possible treatment for visceral and arthritic pain. But concurrent with the expansion of possible conditions amenable to SCS, other studies have questioned the long-term efficacy of SCS for traditional indications. These disparate findings argue strongly for the refinement of selection criteria. The purpose of this study is to identify correlates of outcome for SCS. METHODS: Data were retrospectively collected on 244 patients who underwent a SCS trial at two academic medical centers. Success was predefined as ≥50% pain relief sustained for ≥6 months. Variables analyzed for their association with outcome included demographics, location of pain, diagnosis, presence of coexisting diseases, pain descriptors, opioid and adjuvant medication use, duration and pain relief during trial, and complications. RESULTS: The presence of allodynia and/or hyperalgesia correlated with both a positive SCS trial (P = 0.01) and long-term implantation outcome (P = 0.05). History of substance abuse was associated with a negative permanent SCS outcome (P = 0.05) but bore no relationship to trial results. The variable most strongly associated with an SCS outcome was experiencing <50% pain relief during the trial, which strongly presaged a negative result (P < 0.001). CONCLUSIONS: Although weak associations with outcome were noted for several clinical variables, none was strongly associated with trial and permanent implantation results. The strongest predictor of a negative SCS outcome was obtaining <50% pain relief during the trial period.

Survey of the utilization of regional and general anesthesia in a tertiary teaching hospital.

BACKGROUND: Although the subspecialty of regional anesthesiology has become an important focus during residency training, there are many factors that might influence a resident's experience in regional anesthesia (RA). There are few data examining the utilization of regional techniques in an anesthesiology residency program. We undertook a prospective observational study to determine the frequency and reasons for not choosing RA in cases for which it was considered an option. METHODS: All scheduled operative procedures that were amenable to neuraxial or major peripheral regional anesthetic techniques were surveyed. Data recorded included the type of intraoperative anesthetic used, type of anesthesiology faculty performing the regional block (regional anesthesiologist vs general anesthesiologist), and reasons for not choosing RA when a regional anesthetic technique was feasible. RESULTS: Of the 2301 surgical procedures amenable to a regional technique, 839 (36.5%) involved use of regional anesthetic, and 1462 (63.5%) involved only a general anesthetic. Of the subjects receiving RA, 32% were performed by general anesthesiology faculty, and 68% were performed by regional anesthesiology faculty. The most common type of regional anesthetic performed by the general anesthesiology faculty was neuraxial blockade (95.2%) (vs 52.5% by regional anesthesiology faculty). Of the cases not involving RA, the reasons were anesthesiology related (40%), surgeon related (34%), patient related (12%), and medical contraindication related (14%). CONCLUSIONS: Our prospective observational study suggests that anesthesiology-related reasons may be an important factor for not undertaking these techniques. Although we did not specifically examine the effect on resident education, our study does provide some evidence to support program directors and department chiefs to set up their regional rotations with faculty most likely to perform RA.

Risk factors for brachial plexus injury with and without shoulder dystocia.

OBJECTIVE: To ascertain whether brachial plexus palsy (BPP) that occurs without shoulder dystocia (SD) represents a traction injury during unrecognized SD or a natural phenomenon with a different mechanism of injury, we compared risk factors and outcomes between SD-associated and non-SD-associated BPP. STUDY DESIGN: Neonates with BPP after cephalic vaginal delivery were pooled from all deliveries at Johns Hopkins (June, 1993-December, 2004) and a dataset of litigated permanent BPP from multiple institutions (1986-2003), grouped by SD association based on clinician documentation and compared by using Fisher exact and t tests. RESULTS: Thirty percent of 49 non-SD-BPP and 11% of 280 SD-BPP lacked all risk factors for SD (P = .002). Compared with SD-BPP infants, non-SD-BPP infants were average weight (P < .001) and had cord pH less than 7.10 (P = .01) more commonly and exhibited a trend toward posterior shoulder involvement (P = .06). Nearly all non-SD-BPP were temporary, whereas more than 90% of permanent BPP were associated with SD (odds ratio 17, 7.3-39.6). CONCLUSION: Non-SD-BPP is uncommon and likely mechanistically distinct from SD-BPP. Risk factors, birth weight, fetal acidosis, posterior arm involvement, and injury severity distinguish between shoulder dystocia-related brachial plexus injuries and those not recorded as such.