Wireless high-frequency dorsal root ganglion stimulation for chronic low back pain: A pilot study.

OBJECTIVE: Evaluation of the efficacy of a wireless high-frequency stimulator placed over selected DRG of exiting nerve roots for the treatment of chronic low back pain. DESIGN: Feasibility. SUBJECTS: Six subjects with chronic, intractable back pain refractory to standard medical treatment. METHODS: Four stimulators (Freedom-4A) provided by Stimwave Technologies, were implanted over the DRG exiting nerve roots, bilaterally at both the T9 and L2 vertebral levels. Subjects were asked to evaluate stimulation independently with the devices turned on at T9 and subsequently L2 for each of 2 weeks. Subjects were then monitored for 8 weeks with the preferred stimulator. Pain reduction with the Visual Analog Scale (VAS), functionality with the Oswestry Disability Index (ODI), Patient Global Impression of Change (PGIC) and medication usage were evaluated. RESULTS: Four subjects preferred T9 stimulation with only one subject preferring stimulation at L2. One subject dropped out of the study before conclusion of the 4-week evaluation and is not included in this report. Average pain levels (n = 5) at 12-week post-implantation decreased with 61% for back pain and 56% for leg pain with a significant reduction in pain medication, including a 100% reduction in opioid pain medications. The average reduction in disability was 12%. Subjects reported an average impression of change of 6 (1 = no change, 7 = great deal better). CONCLUSIONS: Wireless high-frequency stimulation of the DRG is a viable option to treat chronic low back pain. Preliminary results show a subject preference for stimulation at the T9 vertebral level.

Evidence-based medicine in anesthesiology.

Two decades ago, Evidence-Based Medicine (EBM) was introduced to improve the quality of medical care. Using EBM in practice can be seen as a cyclic process consisting of 5 steps. This paper explains how to apply these steps in anesthesiology. The EBM cycle involves: 1. Asking a relevant clinical question, 2. Finding evidence to answer the question, 3. Appraising the evidence, 4. Applying the findings to practice, which means integrating evidence, clinical experience and patient preferences, and 5. Reviewing these steps. Applying EMB requires effort and certain skills, for example searching for evidence and appraising the quality of the evidence. Also important is a reflective attitude towards the practitioner's own practice. This paper aims at encouraging anesthesiologists to develop such skills and to implement the steps of EBM in their daily practice.

Evaluation of the neuroprotective effects of S(+)-ketamine during open-heart surgery.

UNLABELLED: We compared the effect of S(+)-ketamine to remifentanil, both in combination with propofol, on the neurocognitive outcome after open-heart surgery in 106 patients. A battery of neurocognitive tests was administered before surgery and 1 and 10 wk after surgery. Fourteen patients (25%) in the control group and 10 patients (20%) in the S(+)-ketamine group had 2 or more tests with a cognitive deficit (decline by at least one preoperative SD of that test in all patients) 10 wk after surgery (P = 0.54). Z-scores were calculated for all tests. No significantly better performance could be detected in the S(+)-ketamine group, except for the Trailmaking B test 10 wk after surgery. We conclude that S(+)-ketamine offers no greater neuroprotection compared with remifentanil during open-heart surgery. IMPLICATIONS: N-methyl-D-aspartic acid receptors play an important role during ischemic brain injury. We could not demonstrate that S(+)-ketamine resulted in greater neuroprotective effects compared with remifentanil during cardiopulmonary bypass procedures when both were combined with propofol.

A prospective randomized study of the potential benefits of thoracic epidural anesthesia and analgesia in patients undergoing coronary artery bypass grafting.

We performed an open, prospective, randomized, controlled study of the incidence of major organ complications in 420 patients undergoing routine coronary artery bypass graft surgery with or without thoracic epidural anesthesia and analgesia (TEA). All patients received a standardized general anesthetic. Group TEA received TEA for 96 h. Group GA (general anesthesia) received narcotic analgesia for 72 h. Both groups received supplementary oral analgesia. Twelve patients were excluded-eight in Group TEA and four in Group GA-because of incomplete data collection. New supraventricular arrhythmias occurred in 21 of 206 patients (10.2%) in Group TEA compared with 45 of 202 patients (22.3%) in Group GA (P = 0.0012). Pulmonary function (maximal inspiratory lung volume) was better in Group TEA in a subset of 93 patients (P < 0.0001). Extubation was achieved earlier (P < 0.0001) and with significantly fewer lower respiratory tract infections in Group TEA (TEA = 31 of 206, GA = 59 of 202; P = 0.0007). There were significantly fewer patients with acute confusion (GA = 11 of 202, TEA = 3 of 206; P = 0.031) and acute renal failure (GA = 14 of 202, TEA = 4 of 206; P = 0.016) in the TEA group. The incidence of stroke was insignificantly less in the TEA group (GA = 6 of 202, TEA = 2 of 206; P = 0.17). There were no neurologic complications associated with the use of TEA. We conclude that continuous TEA significantly improves the quality of recovery after coronary artery bypass graft surgery compared with conventional narcotic analgesia.