Abstract Study Objectives To compare the efficacy of continuous radiofrequency (CRF) thermocoagulation with pulsed radiofrequency (PRF) in the treatment of lumbar facet syndrome. Design Prospective, ...randomized, double-blinded study. Setting Ambulatory pain clinic at a level-I trauma center and teaching institution. Patients 50 ASA physical status I, II, and III patients, at least 18 years of age, scheduled to undergo CRF or PRF for lumbar back pain. Interventions Target facet joints were identified with oblique radiographic views. Continuous radiofrequency thermocoagulation was delivered at 80°C for 75 seconds, while PRF was delivered at 42°C with a pulse duration of 20 ms and pulse rate of two Hz for 120 seconds. Measurements Visual analog scale (VAS) pain assessment and Oswestry Low Back Pain and Disability Questionnaire (OSW) were administered at baseline and then at three months. Comparisons between groups and within groups were made of the relative percentage improvement in VAS and OSW scores. Main Results No significant differences in the relative percentage improvement were noted between groups in either VAS ( P = 0.46) or OSW scores ( P = 0.35). Within the PRF group, comparisons of the relative change over time for both VAS ( P = 0.21) and OSW scores ( P = 0.61) were not significant. However, within the CRF group, VAS ( P = 0.02) and OSW scores ( P = 0.03) showed significant improvement. Conclusions Although there was no significant difference between CRF and PRF therapy in long-term outcome in the treatment of lumbar facet syndrome, there was a greater improvement over time noted within the CRF group.
Climate change is shifting the phenological cycles of plants
, thereby altering the functioning of ecosystems, which in turn induces feedbacks to the climate system
. In northern (north of 30° N) ...ecosystems, warmer springs lead generally to an earlier onset of the growing season
and increased ecosystem productivity early in the season
. In situ
and regional
studies also provide evidence for lagged effects of spring warmth on plant productivity during the subsequent summer and autumn. However, our current understanding of these lagged effects, including their direction (beneficial or adverse) and geographic distribution, is still very limited. Here we analyse satellite, field-based and modelled data for the period 1982-2011 and show that there are widespread and contrasting lagged productivity responses to spring warmth across northern ecosystems. On the basis of the observational data, we find that roughly 15 per cent of the total study area of about 41 million square kilometres exhibits adverse lagged effects and that roughly 5 per cent of the total study area exhibits beneficial lagged effects. By contrast, current-generation terrestrial carbon-cycle models predict much lower areal fractions of adverse lagged effects (ranging from 1 to 14 per cent) and much higher areal fractions of beneficial lagged effects (ranging from 9 to 54 per cent). We find that elevation and seasonal precipitation patterns largely dictate the geographic pattern and direction of the lagged effects. Inadequate consideration in current models of the effects of the seasonal build-up of water stress on seasonal vegetation growth may therefore be able to explain the differences that we found between our observation-constrained estimates and the model-constrained estimates of lagged effects associated with spring warming. Overall, our results suggest that for many northern ecosystems the benefits of warmer springs on growing-season ecosystem productivity are effectively compensated for by the accumulation of seasonal water deficits, despite the fact that northern ecosystems are thought to be largely temperature- and radiation-limited
.
Prostate cancer is the second most common cancer in American men and new surgical techniques have led to less invasive options for prostate surgery. Innovations in robotic technology have enabled ...robotic systems to become a more common sight in operating theatres throughout the United States. Approximately 1,500 consecutive patients scheduled for elective robotic prostatectomy (RP) were reviewed. Patient demographics were recorded and significant intraoperative and postoperative events were reviewed. At our institution the mean age for patients undergoing RP is 60.3 (41-79) years; the mean body mass index is 27.3 kg m(-2). The mean operative time, defined as the time from the start of insufflation to closure is 177.5 (81-365) min and mean blood loss is 109 (50-750) mL. There was a 1.3% incidence of postoperative anemia (hemoglobin <10 g dL) where patients required blood transfusions (15/1,500). Three patients were diagnosed with postoperative pulmonary emboli and were treated with IV heparin with no additional sequelae. The most common anesthesia-related complication was corneal abrasions, which were seen in 3% of cases. One patient required postoperative mechanical ventilation because of laryngeal edema secondary to multiple intubation attempts from an unexpectedly difficult airway. Anesthetic and perioperative complications are rare for patients undergoing robotic-assisted laparoscopic prostatectomy at our institution. Our institution has performed more robotic prostatectomies than any other institution in the world and we review our experience delivering anesthesia for the first 1,500 patients undergoing this operation.
Lymphangioleiomyomatosis is a rare restrictive lung disease that is often associated with pneumothorax and prolonged intubation. We report the successful anesthetic management of a patient with ...lymphangioleiomyomatosis, myasthenia gravis, and idiopathic thrombocytopenic purpura undergoing laparoscopic partial nephrectomy for renal lesions, and discuss anesthetic management strategies for this rare disease process.
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