Robert Jan Stolker

efficacy of Radiofrequency Procedures for the Treatment of Spinal Pain : a Systematic Review of Randomized Clinical Trials

Background and Objectives The use of radiofrequency (RF) procedures in the peripheral nervous system to treat chronic spinal pain has been the subject of controversy. Publications concerned only uncontrolled studies, and irreversible nervous tissue damage was believed to be responsible for the effect, if any. In recent years, randomized, controlled studies have appeared, which have attested to an increasing use of these techniques. This is a systematic review of randomized controlled trials on RF procedures for spinal pain. Methods We performed a standardized literature search for randomized, controlled trials. Three adjudicators independently registered trial methodology and outcome using validated and subject-related instruments. Interadjudicator disagreement was resolved by discussion. It was found necessary to devise additional parameters of study assessment. Results Six trials met the inclusion criteria. This small number, along with clinical and technical heterogeneity precluded statistical analysis. All studies, whether high or low quality, reported positive outcomes. Conclusions We conclude that there is moderate evidence that RF lumbar facet denervation is more effective for chronic low back pain than placebo. Limited evidence exists for efficacy of RF neurotomy in chronic cervical zygapophyseal joint pain after flexion-extension injury. There is limited evidence that RF heating of the dorsal root ganglion is more effective than placebo in chronic cervicobrachialgia. We recommend the systematic application of our additional parameter assessments for future evaluations of RF studies. These additional parameters should also be used in the preparation of future trial protocols of RF procedures for the treatment of chronic pain.

Calcification of the abdominal aorta as an independent predictor of cardiovascular events: a meta-analysis

Context Abdominal aortic calcification (AAC) is a common finding in patients with atherosclerosis. Objective The aim of this study was to demonstrate the incremental value of AAC in predicting long term cardiovascular (CV) outcome by conducting a meta-analysis of observational studies. Data sources MEDLINE and Cochrane databases. Study selection Longitudinal studies with at least 2 years of follow-up, reporting the influence of AAC on CV outcome of general population patients. Data extraction Four separate end points—coronary events, cerebrovascular events, all CV events and CV related death—were tested for their relationship with AAC at baseline, using weighted random effects meta-analysis. Heterogeneity was calculated using Q and I2 statistic tests. Publication bias was assessed by funnel plot symmetry and trim and fill methods. The importance of calcium quantification was also explored (sensitivity analysis). Results 10 studies were included. An increased relative risk (RR) was found for all end points: for coronary events (five studies, n=11250) 1.81 (95% CI 1.54 to 2.14); for cerebrovascular events (four studies, n=9736) 1.37 (1.22 to 3.54); for all CV events (four studies, n=4960) 1.64 (1.24 to 2.17); and for CV death (three studies, n=4986) 1.72 (1.03 to 2.86). Analysis of studies presenting results in categories (no/minimal, moderate and severe calcification) revealed a stepwise increase in the RR for all end points. Significant heterogeneity was found in the included studies. Sources of heterogeneity were identified in the publication date, duration of follow-up, and mean age and gender differences in the included patient cohorts. Conclusion Existing data suggest that AAC is a strong predictor of CV related events or death in the general population. The predictive impact is greater in more calcified aortas. The generalisability of the meta-analysis is limited by heterogeneity in the coronary events, all CV events and CV death end points.

Epidural Analgesia Is Associated with Improved Health Outcomes of Surgical Patients with Chronic Obstructive Pulmonary Disease

Background:Patients with chronic obstructive pulmonary disease (COPD) have increased postoperative morbidity and mortality. Epidural analgesia (EDA) improves postoperative outcome but may worsen postoperative lung function. It is unknown whether patients with COPD benefit from EDA. The objective of this study was to determine whether patients with COPD undergoing major abdominal surgery benefit from EDA in addition to general anesthesia. Methods:This cohort study included 541 consecutive patients with COPD who underwent major abdominal surgery between 1995 and 2007 at a university medical center. Propensity scores estimating the probability of receiving EDA were used in multivariate correction. The primary outcome was postoperative pneumonia and 30-day mortality. Results:There were 324 patients (60%) who received EDA in addition to general anesthesia. The incidence of postoperative pneumonia (16% vs. 11%; P = 0.08) and 30-day mortality (9% vs. 5%; P = 0.03) was lower in patients who received EDA. After correction EDA was associated with improved outcome for postoperative pneumonia (OR 0.5; 95% CI: 0.3–0.9; P = 0.03). The strongest preventive effect was seen in patients with the most severe type of COPD. Conclusion:This study provides evidence that in patients with COPD who are scheduled for major abdominal surgery, epidural analgesia decreases postoperative pulmonary complications.

Stent graft composition plays a material role in the postimplantation syndrome.

OBJECTIVE In patients undergoing endovascular aneurysm repair (EVAR), the postimplantation syndrome (PIS), comprising fever and inflammation, occurs frequently. The cause of PIS is unclear, but graft composition and acute thrombus formation may play a role. The objective of this study was to evaluate these possible causes of the inflammatory response after EVAR. METHODS One hundred forty-nine patients undergoing elective EVAR were included. Implanted stent grafts differed mainly in the type of fabric used: either woven polyester (n=82) or expanded polytetrafluorethylene (ePTFE; n=67). Tympanic temperature and C-reactive protein (CRP) were assessed daily during hospitalization. PIS was defined as the composite of a body temperature of ≥38°C coinciding with CRP>10 mg/L. Besides graft composition, the size of the grafts and the volume of new-onset thrombus were calculated using dedicated software, and results were correlated to PIS. RESULTS Implantation of grafts made of polyester was associated with higher postoperative temperature (P<.001), CRP levels (P<.001), and incidence of PIS (56.1% vs 17.9%; P<.001) compared to ePFTE. After multivariate analysis, woven polyester stent grafts were independently associated with an increased risk of PIS (hazard ratio, 5.6; 95% confidence interval, 1.6-19.4; P=.007). Demographics, amount of graft material implanted, or new-onset thrombus had no association with PIS. CONCLUSIONS The composition of stent grafts may play a material role in the incidence of postimplantation syndrome in patients undergoing EVAR. Implantation of stent grafts based on woven polyester was independently associated with a stronger inflammatory response.

Vitamin D Deficiency may be an Independent Risk Factor for Arterial Disease

OBJECTIVES The aim of this study was to assess the vitamin D status in patients with occlusive or aneurysmatic arterial disease in relation to clinical cardiovascular risk profiles and markers of atherosclerotic disease. METHODS We included 490 patients with symptomatic peripheral arterial disease (PAD, n = 254) or aortic aneurysm (n = 236). Cardiovascular risk factors and comorbidities carotid intima-media thickness (CIMT), ankle-brachial index (ABI), serum high-sensitive C-reactive protein (hs-CRP) and vitamin D were assessed. Patients were categorised into severely (≤25 nmol l(-1)) or moderately (26-50 nmol l(-1)) vitamin D deficient, vitamin D insufficient (51-75 nmol l(-1)) or vitamin D sufficient (>75 nmol l(-1)). RESULTS Overall, 45% of patients suffered from moderate or severe vitamin D deficiency. The prevalence of vitamin D deficiency was similar in patients with PAD and those with an aortic aneurysm. Low levels of vitamin D were associated with congestive heart failure and cerebrovascular disease. Adjusting for clinical cardiovascular risk factors, multivariable regression analyses showed that low vitamin D status was associated with higher CIMT (P = 0.001), lower ABI (P < 0.001) and higher hs-CRP (P = 0.022). CONCLUSIONS The current study shows a strong association between low vitamin D status and arterial disease, independent of traditional cardiovascular risk factors and irrespective of the type of vascular disease, that is, occlusive or aneurysmatic disease.

Radiofrequency lumbar facet denervation: A comparative study of the reproducibility of lesion size after 2 current radiofrequency techniques

Background and objectives Radiofrequency facet denervation procedures are widely used for the treatment of chronic low-back pain. Currently, both temperature-controlled and voltage-controlled techniques are used. In this combined in vivo and in vitro study, the electrophysiologic consequences and the effects on lesion size of these techniques were determined. Methods Thirty-three patients were randomly assigned to receive a lumbar radiofrequency facet denervation by using either temperature-controlled (80°C, 60 seconds) or voltage-controlled (20 V, 60 s) mode. Electrophysiologic parameters in both groups during radiofrequency lesioning were registered. Observed differences between electrodes were quantified and interpreted, using lesion-size data from egg-white experiments. Results Seventeen patients in the temperature group were treated with a total of 55 radiofrequency lesions, all considered technically adequate. In the voltage-controlled group, 16 patients received 63 lesions. Of these, 44 (69.8%) procedures were found to be technically inadequate. Voltage-controlled radiofrequency lesioning resulted in uncontrollable fluctuations of temperature, with resultant uncontrollable variations in lesion size. Temperature-controlled mode created reproducible lesion sizes. Conclusions There is no consistent relation between voltage and the temperature obtained during radiofrequency lumbar facet denervation. Temperature-controlled radiofrequency lesioning is preferred to create reproducible lesion sizes.

Early sac shrinkage predicts a low risk of late complications after endovascular aortic aneurysm repair

Aneurysm shrinkage has been proposed as a marker of successful endovascular aneurysm repair (EVAR). Patients with early postoperative shrinkage may experience fewer subsequent complications, and consequently require less intensive surveillance.

Defining the learning curve for endotracheal intubation using direct laryngoscopy: A systematic review

More than two failed intubation attempts and failed endotracheal intubations (ETIs) are associated with severe complications and death. The aim of this review was to determine the number of ETIs a health care provider in training needs to perform to achieve proficiency within two attempts. A systematic search of the literature was conducted covering the time frame of January 1990 through July 2014. We identified 13 studies with a total of 1462 students who had attempted to intubate 19,108 patients. This review shows that in mostly elective circumstances, at least 50 ETIs with no more than two intubation attempts need to be performed to reach a success rate of at least 90%. However, the evidence is heterogeneous, and the incidence of difficult airways in non-elective settings is up to 20 times higher compared to elective settings. Taking this factor into account, training should include a variety of exposures and should probably exceed 50 ETIs to successfully serve the most vulnerable patients.

Oxygen-dependent delayed fluorescence measured in skin after topical application of 5-aminolevulinic acid.

Mitochondrial oxygen tension can be measured in vivo by means of oxygen-dependent quenching of delayed fluorescence of protoporphyrin IX (PpIX). Here we demonstrate that delayed fluorescence is readily observed from skin in rat and man after topical application of the PpIX precursor 5-aminolevulinic acid (ALA). Delayed fluorescence lifetimes respond to changes in inspired oxygen fraction and blood supply. The signals contain lifetime distributions and the fitting of rectangular distributions to the data appears more adequate than mono-exponential fitting. The use of topically applied ALA for delayed fluorescence lifetime measurements might pave the way for clinical use of this technique.

Ultrasonographic measured optic nerve sheath diameter as an accurate and quick monitor for changes in intracranial pressure

OBJECT Ultrasonographic measurement of the optic nerve sheath diameter (ONSD) is known to be an accurate monitor of elevated intracranial pressure (ICP). However, it is yet unknown whether fluctuations in ICP result in direct changes in ONSD. Therefore, the authors researched whether ONSD and ICP simultaneously change during tracheal manipulation in patients in the intensive care unit (ICU) who have suffered a traumatic brain injury (TBI). MATERIALS The authors included 18 ICP-monitored patients who had sustained TBI and were admitted to the ICU. They examined the optic nerve sheath by performing ultrasound before, during, and after tracheal manipulation, which is known to increase ICP. The correlation between ONSD and ICP measurements was determined, and the diagnostic performance of ONSD measurement was tested using receiver operating characteristic curve analysis. RESULTS In all patients ICP increased above 20 mm Hg during manipulation of the trachea, and this increase was directly associated with a dilation of the ONSD of > 5.0 mm. After tracheal manipulation stopped, ICP as well as ONSD decreased immediately to baseline levels. The correlation between ICP and ONSD was high (R(2) = 0.80); at a cutoff of ≥ 5.0 mm ONSD, a sensitivity of 94%, a specificity of 98%, and an area under the curve of 0.99 (95% CI 0.97-1.00) for detecting elevated ICP were determined. CONCLUSIONS In patients who have sustained a TBI, ultrasonography of the ONSD is an accurate, simple, and rapid measurement for detecting elevated ICP as well as immediate changes in ICP. Therefore, it might be a useful tool to monitor ICP, especially in conditions in which invasive ICP monitoring is not available, such as at trauma scenes.