Psychophysical or spinal reflex measures when assessing conditioned pain modulation?

Background: Assessing conditioning pain modulation (CPM) with spinal reflex measures may produce more objective and stable CPM effects than using psychophysical measures. The aim of the study was to compare the CPM effect and test–retest reliability between a psychophysical protocol with thermal test‐stimulus and a spinal reflex protocol with electrical test‐stimulus. Methods: Twenty‐five healthy volunteers participated in two identical experiments separated by minimum 1 week. The thermal test‐stimulus was a constant heat stimulation of 120 s on the subjects’ forearm with continuous ratings of pain intensity on a 10 cm visual analogue scale. The electrical test‐stimulus was repeated electrical stimulation on the arch of the foot for 120 s, which elicited a nociceptive withdrawal reflex recorded from the anterior tibial muscle. Conditioning stimulus was a 7°C water bath. Differences in the magnitude and test–retest reliability were investigated with repeated‐measures analysis of variance and by relative and absolute reliability indices. Results: The CPM effect was −46% and 4.5% during the thermal and electrical test‐stimulus (p < 0.001) respectively. Intraclass correlation coefficient of 0.5 and 0.4 was found with the electrical and thermal test‐stimulus respectively. Wide limits of agreement were found for both the electrical (−3.4 to 3.8 mA) and the thermal test‐stimulus (−3.2 to 3.6 cm). Conclusions: More pronounced CPM effect was demonstrated when using a psychophysical protocol with thermal test‐stimulus compared to a spinal reflex protocol with electrical test‐stimulus. Fair relative reliability and poor absolute reliability (due to high intraindividual variability) was found in both protocols. Significance: The large difference in CPM effect between the two protocols suggests that the CPM effect relates to pain perception rather than nociception on the spinal level. Due to poor absolute intrarater reliability, we recommend caution and further research before using any of the investigated CPM protocols in clinical decision making on an individual level

The MAP-HAND : psychometric properties and differences in activity performance between patients with carpometacarpal osteoarthritis and rheumatoid arthritis

Objective: To assess construct validity (Rasch analyses) of the Measure of Activity Performance of the Hand (MAP-Hand) in people with carpometacarpal osteoarthritis (CMC1 OA), and to explore differences in activity performance between people with CMC1 OA and those with rheumatoid arthritis. Design: Cross-sectional study. Subjects: A total of 180 people with CMC1 OA referred for surgical consultation were recruited from rheumatology clinics in Norway, and 340 people with rheumatoid arthritis were recruited from outpatient rheumatology clinics in the UK. Methods: The MAP-Hand consists of 18 predefined items scored on a 4-point scale from 1 (no difficulty) to 4 (unable to do), from which a mean score is calculated. Construct validity was assessed using Rasch analyses. Differences between the 2 groups were assessed using an independent sample t-test at the group level and differential item functioning (condition as grouping variable) at the item level. Results: Some mis-targeting of data and clusters of dependency were found, but the MAP-Hand scores showed an overall fit to the model. No between group difference in total mean MAP-Hand score was found, but there were significant differences between the 2 groups on item levels. Conclusion: The MAP-Hand showed satisfactory construct validity and could differentiate between people with CMC1 OA and those with rheumatoid arthritis on item levels

Myocardial energy metabolism and ultrastructure with polarizing and depolarizing cardioplegia in a porcine model

OBJECTIVES: This study investigated whether the novel St. Thomas’ Hospital polarizing cardioplegic solution (STH-POL) with esmolol/adenosine/magnesium offers improved myocardial protection by reducing demands for high-energy phosphates during cardiac arrest compared to the depolarizing St. Thomas’ Hospital cardioplegic solution No 2 (STH-2). METHODS: Twenty anaesthetised pigs on tepid cardiopulmonary bypass were randomized to cardiac arrest for 60 min with antegrade freshly mixed, repeated, cold, oxygenated STH-POL or STH-2 blood cardioplegia every 20 min. Haemodynamic variables were continuously recorded. Left ventricular biopsies, snap-frozen in liquid nitrogen or fixed in glutaraldehyde, were obtained at Baseline, 58 min after cross-clamp and 20 and 180 min after weaning from bypass. Adenine nucleotides were evaluated by high-performance liquid chromatography, myocardial ultrastructure with morphometry. RESULTS: With STH-POL myocardial creatine phosphate was increased compared to STH-2 at 58 min of cross-clamp [59.9 ± 6.4 (SEM) vs 44.5 ± 7.4 nmol/mg protein; P < 0.025], and at 20 min after reperfusion (61.0 ± 6.7 vs 49.0 ± 5.5 nmol/mg protein; P < 0.05), ATP levels were increased at 20 min of reperfusion with STH-POL (35.4 ± 1.1 vs 32.4 ± 1.2 nmol/mg protein; P < 0.05). Mitochondrial surface-to-volume ratio was decreased with polarizing compared to depolarizing cardioplegia 20 min after reperfusion (6.74 ± 0.14 vs 7.46 ± 0.13 µm2/µm3; P = 0.047). None of these differences were present at 180 min of reperfusion. From 150 min of reperfusion and onwards, cardiac index was increased with STH-POL; 4.8 ± 0.2 compared to 4.0 ± 0.2 l/min/m2 (P = 0.011) for STH-2 at 180 min. CONCLUSIONS: Polarizing STH-POL cardioplegia improved energy status compared to standard STH-2 depolarizing blood cardioplegia during cardioplegic arrest and early after reperfusion.publishedVersio

Comparing the costs and outcomes of an integrated twin compression screw (ITCS) nail with standard of care using a single lag screw or a single helical blade cephalomedullary nail in patients with intertrochanteric hip fractures

© 2018 The Author(s). Background: Surgical treatment is the optimal strategy for managing intertrochanteric fractures as it allows for early rehabilitation and functional recovery. The purpose of the study was to assess the cost-effectiveness of commonly used cephalomedullary nails for the treatment of unstable intertrochanteric hip fractures. Methods: A decision analytic model was developed from a US payer's perspective using clinical data from a pairwise meta-analysis of randomised controlled trials (RCTs) and comparative observational studies comparing the integrated twin compression screw (ITCS) nail versus two single-screw or blade cephalomedullary nails [single lag screw (SLS) nail and single helical blade (SHB) nail]. The model considered a cohort of 1000 patients with a mean age of 76, as reported in the clinical studies over a 1-year time period. Cost data was obtained from the Center for Medicare and Medicaid Services website and published literature and adjusted for inflation. One-way and probabilistic sensitivity analyses were conducted to assess the effect of uncertainty in model parameters on model conclusions. Results: The model estimated 0.546 quality-adjusted life years (QALYs) and 0.78 complications avoided by using the ITCS nail and 0.455 QALYs and 0.67 complications avoided for the standard of care, using SLS or SHB nails. The cost per patient was $34,336 for patients treated with an ITCS nail and$37,036 for patients treated with the standard of care respectively, resulting in a cost saving of $2700 in favour of the ITCS nail. More savings were observed when the ITCS nail was compared to the SHB ($3280 per patient) and SLS ($1652 per patient). The findings were robust to a range of both one-way and the probabilistic sensitivity analyses. Conclusion: In conclusion, the ITCS nail can be considered a cost saving intervention in patients undergoing intertrochanteric fracture fixation with an intramedullary device. Clinicians and policy makers should be encouraged to adopt healthcare technologies such as ITCS that will help them to provide quality healthcare despite falling budgets

Evoked potentials in the Atlantic cod following putatively innocuous and putatively noxious electrical stimulation: a minimally invasive approach

Aspects of peripheral and central nociception have previously been studied through recording of somatosensory evoked potentials (SEPs) to putative noxious stimuli in specific brain regions in a few freshwater fish species. In the present study, we describe a novel, minimally invasive method for recording SEPs from the central nervous system of the Atlantic cod (Gadus morhua). Cutaneous electric stimulation of the tail in 15 fish elicited SEPs at all stimulus intensities (2, 5, 10 and 20 mA) with quantitative properties corresponding to stimulus intensity. In contrast to previous fish studies, the methodological approach used in Atlantic cod in the current study uncovered a number of additional responses that could originate from multiple brain regions. Several of these responses were specific to stimulation at the highest stimulus intensities, possibly representing qualitative differences in central processing between somatosensory and nociceptive stimuli

The vulnerabilities of agricultural land and food production to future water scarcity

Rapidly increasing populations coupled with increased food demand requires either an expansion of agriculturalland or sufficient production gains from current resources. However, in a changing world, reduced wateravailability might undermine improvements in crop and grass productivity and may disproportionately affectdifferent parts of the world. Using multi-model studies, the potential trends, risks and uncertainties to land useand land availability that may arise from reductions in water availability are examined here. In addition, theimpacts of different policy interventions on pressures from emerging risks are examined.Results indicate that globally, approximately 11% and 10% of current crop- and grass-lands could be vul-nerable to reduction in water availability and may lose some productive capacity, with Africa and the MiddleEast, China, Europe and Asia particularly at risk. While uncertainties remain, reduction in agricultural land areaassociated with dietary changes (reduction of food waste and decreased meat consumption) offers the greatestbuffer against land loss and food insecurity