Martin Posch

Reliability and validity of the Medical Research Council (MRC) scale and a modified scale for testing muscle strength in patients with radial palsy.

OBJECTIVE To assess the inter-rater and intra-rater reliability and validity of the original and a modified Medical Research Council scale for testing muscle strength in radial palsy. DESIGN Prospective, randomized validation study. PATIENTS Thirty-one patients with peripheral paresis of radial innervated forearm muscles were included. METHODS Wrist extension, finger extension and grip strength were evaluated by manual muscle testing. Dynamometric measurement of grip strength was performed. Pair-wise weighted kappa coefficients were calculated to determine inter-rater and intra-rater reliability. The 2 scores were compared using the signed-rank test. Spearmans correlation coefficients of the maximal relative force measurements with the median (over-raters) Medical Research Council and modified Medical Research Council scores were calculated to determine validity. RESULTS Inter-rater agreement of the Medical Research Council scale (finger extension: 0.77; wrist extension: 0.78; grip strength: 0.78) and the modified Medical Research Council scale (finger extension: 0.81; wrist extension: 0.78; grip strength: 0.81) as well as intra-rater agreement of the Medical Research Council scale (finger extension: 0.86; wrist extension: 0.82; grip strength: 0.84) and the modified Medical Research Council scale (finger extension: 0.84, wrist extension: 0.81; grip strength: 0.88) showed almost perfect agreement. Spearmans correlation coefficients of the maximal relative force measurements with the median Medical Research Council and modified Medical Research Council score were both 0.78. CONCLUSION Medical Research Council and modified Medical Research Council scales are measurements with substantial inter-rater and intra-rater reliability in evaluating forearm muscles.

The SCARF osteotomy for the correction of hallux valgus deformities.

The authors report their experience with a modified SCARF osteotomy with three years follow-up. Correction of moderate to severe hallux valgus deformities was achieved using a Z step osteotomy cut to realign the first metatarsal bone. A retrospective analysis was undertaken in 89 consecutive patients (111 feet). Results were analyzed by clinical examination, a questionnaire including the AOFAS forefoot score, and plain roentgenograms. Hallux valgus and intermetatarsal angle improved at mean 19.1° and 6.6°, respectively. Mean forefoot score improved from 50.1 to 91 points out of 100 possible points. Satisfactory healing time was expressed by an average return back to work of 5.8 weeks and back to sport of 8.3 weeks. Persistence or recurrence of hallux valgus was seen in seven patients (6%). The complication rate was 5.4% including superficial wound infection, traumatic dislocation of the distal fragment, and hallux limitus. The presented technique provides predictable correction of moderate to severe hallux valgus deformities.

Preoperative anaemia is associated with poor clinical outcome in non-cardiac surgery patients

BACKGROUND Retrospective studies suggest that preoperative anaemia is associated with poor outcomes after surgery. The objective of this study was to describe mortality rates and patterns of intensive care resource use for patients with anaemia undergoing non-cardiac and non-neurological in-patient surgery. METHODS We performed a secondary analysis of a large prospective study describing perioperative care and survival in 28 European nations. Patients at least 16 yr old undergoing in-patient surgery during a 7 day period were included in the study. Data were collected for in-hospital mortality, duration of hospital stay, admission to intensive care, and intensive care resource use. Multivariable logistic regression analysis was performed to understand the effects of preoperative haemoglobin (Hb) levels on in-hospital mortality. RESULTS We included 39 309 patients in the analysis. Preoperative anaemia had a high prevalence in both men and women (31.1% and 26.5%, respectively). Multivariate analysis showed that patients with severe [odds ratio 2.82 (95% confidence interval 2.06-3.85)] or moderate [1.99 (1.67-2.37)] anaemia had higher in-hospital mortality than those with normal preoperative Hb concentrations. Furthermore, hospital length of stay (P<0.001) and postoperative admission to intensive care (P<0.001) were greater in patients with anaemia than in those with normal Hb concentrations. CONCLUSIONS Anaemia is common among non-cardiac and non-neurological surgical patients, and is associated with poor clinical outcome and increased healthcare resource use. CLINICAL TRIAL REGISTRATION NCT01203605 (ClinicalTrials.gov).

Impact of dental implant length on early failure rates: a meta-analysis of observational studies

AIM To test the null hypothesis of no difference in failure rates of short (minimum length: 7 mm) and longer dental implants (≥ 10 mm), a meta-analysis was performed on prospective observational trials. MATERIALS AND METHODS A systematic electronic and hand search was performed to identify eligible studies. Having additional data supplied by the authors, 54 publications were included (19,083 implants). RESULTS In case of mandibular implants, the null hypothesis of no impact of reduced implant length on failure within the first year of prosthetic loading could not be rejected. A significant impact of implant length could be substantiated for short machined implants in the anterior [odds ratio (OR) 5.4] and posterior maxilla (OR 3.4), while short rough-surfaced implants demonstrated increased failure rates in the anterior maxillary sites. No influence of implant diameter and denture type on the failure rate of short implants could be revealed. CONCLUSION In areas of reduced alveolar bone height the use of short dental implants may reduce the need for invasive bone augmentation procedures.

Morphine Decreases Clopidogrel Concentrations and Effects A Randomized, Double-Blind, Placebo-Controlled Trial

OBJECTIVES This study sought to examine the possible drug-drug interactions between clopidogrel and morphine. BACKGROUND Because morphine-the recommended treatment for pain of myocardial infarction-is associated with poor clinical outcome, we hypothesized that morphine lowers the plasma levels of clopidogrel active metabolite as well as its effects on platelets. METHODS Twenty-four healthy subjects received a loading dose of 600 mg clopidogrel together with placebo or 5 mg morphine intravenously in a randomized, double-blind, placebo-controlled, cross-over trial. Pharmacokinetics was determined by liquid chromatography tandem mass spectrometry, and clopidogrel effects were measured by platelet function tests. RESULTS Morphine injection delayed clopidogrel absorption (p = 0.025) and reduced the area under the curve levels of its active metabolite by 34% (p = 0.001). Morphine delayed the maximal inhibition of platelet aggregation on average by 2 h (n = 24; p < 0.001). Residual platelet aggregation was higher 1 to 4 h after morphine injection (n = 24; p < 0.005). Furthermore, morphine delayed the inhibition of platelet plug formation under high shear rates (P2Y-Innovance; n = 21; p < 0.004) and abolished the 3-fold prolongation in collagen adenosine diphosphate-induced closure times seen in extensive and rapid metabolizers (n = 16; p = 0.001). CONCLUSIONS Morphine delays clopidogrel absorption, decreases plasma levels of clopidogrel active metabolite, and retards and diminishes its effects, which can lead to treatment failure in susceptible individuals. (Drug/Drug Interactions of Aspirin and P2Y12-inhibitors; NCT01369186).

Clinical Features, Classification and Prognosis of Migraine and Tension-Type Headache in Children and Adolescents: A Long-Term Follow-Up Study

We performed a long-term follow-up examination in children and adolescents with migraine and tension-type headache (TTH) in order to investigate the evolution of clinical features and headache diagnoses, to compare International Classification of Headache Disorders (ICHD)-I and ICHD-II criteria and to identify prognostic factors. We re-examined 227 patients (52.4± female, age 17.6 ± 3.1 years) 6.6 ± 1.6 years after their first presentation to a headache centre using identical semistructured questionnaires. Of 140 patients initially diagnosed with migraine, 25.7± were headache free, 48.6± still had migraine and 25.7± had TTH at follow-up. Of 87 patients with TTH, 37.9± were headache free, 41.4± still had TTH and 20.7± had migraine. The number of subjects with definite migraine was higher in ICHD-II than in ICHD-I at baseline and at follow-up. The likelihood of a decrease in headache frequency decreased with a changing headache location at baseline (P < 0.0001), with the time between baseline and follow-up (P = 0.0019), and with an initial diagnosis of migraine (P = 0.014). Female gender and a longer time between headache onset and first examination tended to have an unfavourable impact. In conclusion, 30± of the children and adolescents presenting to a headache centre because of migraine or TTH become headache-free in the long-term. Another 20–25± shift from migraine to TTH or vice versa. ICHD-II criteria are superior to those of ICHD-I in identifying definite migraine in children and adolescents presenting to a headache centre. The prognosis is adversely affected by an initial diagnosis of migraine and by changing headache location, and it tends to be affected by an increasing time between headache onset and first presentation.

Diuretic potential of energy drinks

Summary.Recent literature suggests that both caffeine and taurine can induce diuresis and natriuresis in rat and man. Although they act via different cellular mechanisms, their diuretic actions might be additive. This is of considerable interest, as several commercially available energy drinks contain both substances.In this study we examined the possible diuretic effects of caffeine and taurine in a cross-over-design in which 12 healthy male volunteers received each of 4 different test drinks (750 ml of energy drink containing 240 mg caffeine and 3 g taurine, the three other test drinks either lacked caffeine, taurine or both) after restraining from fluids for 12 h.Mixed model analyses demonstrated that urinary output and natriuresis were significantly increased by caffeine (mean differences 243 ml and 27 mmol; both p < 0.001) and that there were no such effects of taurine (mean differences 59 ml and −4 mmol). Additionally, urinary osmolarity at baseline was significantly related to the urinary output (p < 0.001). Urine osmolarity values at baseline and in the 6 h urine collection did not differ significantly between treatments.Taken together, our study demonstrates that diuretic and natriuretic effects of the tested energy drink were largely mediated by caffeine. Taurine played no significant role in the fluid balance in moderately dehydrated healthy young consumers. Consequently, the diuretic potential of energy drinks will not differ significantly from other caffeine containing beverages.

Muscle fatigue and fatigue-related biomechanical changes during a cyclic lifting task.

Study Design. Electromyographic and biomechanical methods were utilized to investigate correlations between indexes of localized muscle fatigue and changes in the kinematics and kinetics of motion during a cyclic lifting task. Summary of Background Data. Recent advances in time-frequency analysis procedures for electromyographicic signal processing provide a new way of studying localized muscle fatigue during dynamic contractions. These methods provide a means to investigate fatigue-related functional impairments in patients with low back pain. Objectives. To study the relationship between localized muscle fatigue and the biomechanics of lifting and lowering a weighted box. Fatigue-related changes in the electromyographicic signal of trunk and limb muscles were evaluated and compared to kinematic and kinetic measures in order to determine whether lifting strategy is modified with fatigue. Methods. A total of 14 healthy male subjects (26 ± 5 years) cyclically lifted and lowered a 13 kg box (12 lifts/min) for 4.5 minutes. A 5-second static maximum lifting task was included immediately before and after the cyclic lifting task to measure changes in lifting strength and static electromyographicic fatigue indexes. Electromyographic signals from 14 muscle sites (including paravertebral and limb muscles) were measured. Changes in the electromyographicic Instantaneous Median Frequency, a fatigue index, were computed using time-frequency analysis methods. This index was compared with more standardized measures of fatigue, such as those based on electromyographicic median frequency acquired during a static trunk extension test, subjective fatigue measures, and maximal static lifting strength. Biomechanical measures were gathered using a motion analysis system to study kinematic and kinetic changes during the lifting task. Results. During the cyclic lifting task, the electromyographic Instantaneous Median Frequency significantly decreased over time in the paravertebral muscles, but not in the limb muscles. Paravertebral electromyographicic Instantaneous Median Frequency changes were consistent with self-reports of fatigue as well as decreases in trunk extension strength. The magnitude of muscle-specific changes in electromyographicic Instantaneous Median Frequency was not significantly correlated with electromyographicic median frequency changes from the static trunk extension task. The load of the box relative to the maximal static lifting strength significantly affected the electromyographicic Instantaneous Median Frequency changes of paravertebral back muscles. Significant changes with fatigue during the task were found in the angular displacements at the knee, hip, trunk, and elbow. These biomechanical changes were associated with increased peak torque and forces at the L4–L5 vertebral segment. Conclusions. Our results demonstrate correlation between localized muscle fatigue and biomechanical adaptations that occur during a cyclic lifting task. This new technique may provide researchers and clinicians with a means to investigate fatigue-related effects of repetitive work tasks or assessment procedures that might be useful in improving education, lifting ergonomy, and back school programs. Although both the dynamic and static tasks resulted in spectral shifts in the electromyographicic data, the fact that these methods led to different muscle-specific findings indicates that they should not be considered as equivalent assessment procedures.

Clinical ResearchAntithrombotic TherapyMorphine Decreases Clopidogrel Concentrations and Effects: A Randomized, Double-Blind, Placebo-Controlled Trial

OBJECTIVES This study sought to examine the possible drug-drug interactions between clopidogrel and morphine. BACKGROUND Because morphine-the recommended treatment for pain of myocardial infarction-is associated with poor clinical outcome, we hypothesized that morphine lowers the plasma levels of clopidogrel active metabolite as well as its effects on platelets. METHODS Twenty-four healthy subjects received a loading dose of 600 mg clopidogrel together with placebo or 5 mg morphine intravenously in a randomized, double-blind, placebo-controlled, cross-over trial. Pharmacokinetics was determined by liquid chromatography tandem mass spectrometry, and clopidogrel effects were measured by platelet function tests. RESULTS Morphine injection delayed clopidogrel absorption (p = 0.025) and reduced the area under the curve levels of its active metabolite by 34% (p = 0.001). Morphine delayed the maximal inhibition of platelet aggregation on average by 2 h (n = 24; p < 0.001). Residual platelet aggregation was higher 1 to 4 h after morphine injection (n = 24; p < 0.005). Furthermore, morphine delayed the inhibition of platelet plug formation under high shear rates (P2Y-Innovance; n = 21; p < 0.004) and abolished the 3-fold prolongation in collagen adenosine diphosphate-induced closure times seen in extensive and rapid metabolizers (n = 16; p = 0.001). CONCLUSIONS Morphine delays clopidogrel absorption, decreases plasma levels of clopidogrel active metabolite, and retards and diminishes its effects, which can lead to treatment failure in susceptible individuals. (Drug/Drug Interactions of Aspirin and P2Y12-inhibitors; NCT01369186).

Nanoscalic silver possesses broad-spectrum antimicrobial activities and exhibits fewer toxicological side effects than silver sulfadiazine

UNLABELLED Silver has been used successfully for decades as an antibacterial agent and has become a standard treatment for burns and bacterial skin infections. Silver-containing creams, particularly silver sulfadiazine (SSD), possess effective activities against bacteria and fungi. However, there is serious concern that silver ions applied to denuded skin might be absorbed in significant amounts, thus introducing the risk of silver deposition, potentially leading to internal organ injury. In view of these facts we compared the percutaneous absorption and the antimicrobial potency of SSD with a new composition, nanoscalic silver (NSAg). In a murine model topical application of NSAg resulted in significantly lower percutaneous absorption and internal organ deposition compared to SSD. Strikingly, antimicrobial activity of NSAg used as a 0.1% formulation was comparable not only with 0.1% SSD against different bacterial strains including methicillin-resistant Staphylococcus aureus, but also against different yeast and dermatophyte species. FROM THE CLINICAL EDITOR Nanoscale silver (NSAg) was demonstrated to have significantly lower percutaneous absorption and less accumulation in multiple organs when applied to denuded skin. Its antimicrobial activity against MRSA was not only comparable to silver sulfadiazine, but the formulation was also effective against different yeast and dermatophyte species.