Exploration of the occupational and personal dimensions impacted by the COVID-19 pandemic for nurses: A qualitative analysis of survey responses.

AIM: To explore the occupational and personal life dimensions that have been impacted by the COVID-19 pandemic for registered nurses (RN) and licensed practical nurses (LPN). DESIGN: Qualitative interpretive description approach. METHODS: Between July and September 2020, a web-based cross-sectional study was conducted among RNs and LPNs in Quebec, Canada. Included in this survey was an open-ended question allowing nurses to describe the occupational and personal life dimensions that were impacted by the COVID-19 pandemic. Thematic analysis was used to interpret the qualitative data from this open-ended question. Reporting followed the Standards For Reporting Qualitative Research (SRQR). RESULTS: Of the 1860 survey respondents, 774 RNs and 43 LPNs responded to the open-ended question (total n = 819). For the occupational dimension, six themes were identified: impacts of infection control on work, change in daily work tasks, offloading and reorganization of care, deterioration of working conditions, increased stress at work and issues related to the profession. For the personal dimension, four themes were found: impacts on the family, dealing with changes about leisure and personal life, impacts on physical and psychological health. CONCLUSION: Knowing the dimensions affected by the COVID-19 pandemic could help to identifying appropriate interventions to support RNs and LPNs. IMPACT: The COVID-19 pandemic has significantly impacted the occupational and personal lives RNs and LPNs working in the Quebec healthcare system. More specifically, Quebec's nurses experienced a major reorganization of care generated by important government decisions. Knowing how the pandemic affected different life dimensions will help in the development of support adapted to nurses' realities. Even in a pandemic context, improvements in the work environment or appropriate support could lead to an improved psychological health for nurses.

Effects of an educational intervention to strengthen humanistic practice on haemodialysis nurses' caring attitudes and behaviours and quality of working life: a cluster randomised controlled trial.

BACKGROUND: Nurses are trained to establish a trusting relationship with patients to create an environment promoting patients' quality of life. However, in tech-heavy care settings, such as haemodialysis units, dehumanising practices may emerge and take root for various reasons to the potential detriment of both patients and nurses. For patients, this may lead to a deterioration of quality of life and, ultimately, of health status. For nurses, it may cause a deterioration of the work environment and, in turn, of quality of working life. Based on Watson's Theory of Human Caring, we developed a brief educational intervention for haemodialysis nurses to strengthen their humanistic practice in the aim of improving the nurse-patient relationship and nurse quality of working life.. The intervention was tested by way of an experimental design. METHODS: One hundred and one haemodialysis nurses, recruited in ten hospitals in French-speaking Switzerland, were randomised into an experimental group that received the intervention and a control group. The nurse-patient relationship was measured with the Caring Nurse-Patient Interaction Scale (EIIP-70) and nurse quality of life at work was measured with the Quality of Work Life Questionnaire at four time points: pre-intervention, intervention completion, and six-month and one-year follow-ups. Random intercept regression analysis was used to evaluate change over time in the two variables under study. RESULTS: The intervention appeared to reinforce nurse attitudes and behaviours geared to a more humanistic practice. The effect seemed to fade over time but, 1 year post-intervention, six dimensions of the nurse-patient relationship (hope, sensibility, helping relationship, expression of emotions, problem solving, teaching) scored above baseline. Nurse quality of working life, too, seemed positively impacted. The cultural dimension of nurse quality of working life, that is, the degree to which everyday work activities attune with personal and cultural values, seemed positively impacted, as well, with improvement stable throughout the year following the intervention. CONCLUSIONS: Results support a positive effect of the intervention over both the short term and the medium-to-long term. A brief intervention of the sort may constitute an effective means to improve the nurse-patient relationship by preventing or reducing dehumanising practices. TRIAL REGISTRATION: NCT03283891 .

A double-blind, placebo-controlled trial of triheptanoin in adult polyglucosan body disease and open-label, long-term outcome.

BACKGROUND: Adult polyglucosan body disease (APBD) is a progressive neurometabolic disorder caused by a deficiency of glycogen branching enzyme. We tested the efficacy of triheptanoin as a therapy for patients with APBD based on the hypothesis that decreased glycogen degradation leads to brain energy deficit. METHODS AND RESULTS: This was a two-site, randomized crossover trial of 23 patients (age 35-73 years; 63% men) who received triheptanoin or vegetable oil as placebo. The trial took place over 1 year and was followed by a 4-year open-label phase. Generalized linear mixed models were used to analyze this study. At baseline, using the 6-min walk test, patients could walk a mean of 389 ± 164 m (range 95-672; n = 19), highlighting the great clinical heterogeneity of our cohort. The overall mean difference between patients on triheptanoin versus placebo was 6 m; 95% confidence interval (CI) -11 to 22; p = 0.50. Motion capture gait analysis, gait quality, and stair climbing showed no consistent direction of change. All secondary endpoints were statistically nonsignificant after false discovery rate adjustment. Triheptanoin was safe and generally well tolerated. During the open-label phase of the study, the most affected patients at baseline kept deteriorating while mildly disabled patients remained notably stable up to 4 years. CONCLUSIONS: We cannot conclude that triheptanoin was effective in the treatment of APBD over a 6-month period, but we found it had a good safety profile. This study also emphasizes the difficulty of conducting trials in very rare diseases presenting with a wide clinical heterogeneity. ClinicalTrials.gov Identifier: NCT00947960.

Anderson-Type Polyoxometalates Functionalized by Tetrathiafulvalene Groups: Synthesis, Electrochemical Studies, and NLO Properties.

Three polyoxometalates (POMs) functionalized by tetrathiafulvalene (TTF) molecules have been synthesized by a coupling reaction between the Anderson-type POMs [MnMo6O18{(OCH2)3CNH2}2]3- or [AlMo6O18(OH)3{(OCH2)3CNH2}]3- and the TTF carboxylic acid derivative (MeS)3TTF(S-CH2-CO2H). The monofunctionalized TTF-AlMo6 POM contains one TTF group covalently grafted on an Al Anderson platform. The symmetrical TTF-MnMo6-TTF POM possesses two TTF groups grafted on each side of a Mn Anderson derivative while the asymmetrical TTF-MnMo6-SP POM contains a TTF and a spiropyran groups. These three trianionic species have been characterized by elemental analysis, 1H and 13C NMR, FT-IR spectroscopy, ESI-MS spectrometry, and single-crystal X-ray diffraction (for TTF-MnMo6-TTF). In the solid state, the grafted TTF molecules of TTF-MnMo6-TTF POMs interact via S···S and π···π interactions and form chains. The electrochemical properties of the complexes reflect the contributions of both the inorganic POM and the TTF moieties. Despite adsorption of the oxidized hybrid species on the Pt grid working electrode, UV-vis-NIR spectroelectrochemical investigations evidence peaks characteristic of the oxidation of the TTF units. Finally, hyper-Rayleigh scattering (HRS) measurements show that the three novel TTF derivatives exhibit ß values between 20 and 37 × 10-30 esu. Moreover it is observed that the oxidation of the TTF moieties by Fe3+ ions increases the NLO response. These values are in the order of magnitude of that found for the well-known 4-dimethylamino- N-methyl-4-stilbazolium (DAS+) cation (ß = 60 × 10-30 esu).

Effects on nurses' quality of working life and on patients' quality of life of an educational intervention to strengthen humanistic practice among hemodialysis nurses in Switzerland: a protocol for a mixed-methods cluster randomized controlled trial.

BACKGROUND: Humanistic nursing practice constitutes the cornerstone of the nursing profession. However, according to some authors, such practice tends to fade over time in favour of non-humanistic behaviours. To contrast this tendency, an educational intervention (EI) based on Watson's Theory of Human Caring was developed and tested in two pilot studies involving, respectively, rehabilitation nurses in Quebec (Canada) and haemodialysis (HD) nurses in Switzerland. In light of the positive results obtained in these, another study is being undertaken to examine more in depth the EI's effects on both HD nurses and patients in French Switzerland. The EI is expected to have positive effects on quality of nurse-patient relationship (NPR), team cohesion, nurse quality of working life (QoWL), and patient quality of life (QoL). METHODS/DESIGN: The study described in this protocol will use a mixed-method cluster randomised controlled trial design. For the quantitative component, nurse and patient data will be collected through questionnaires. The accessible population of 135 nurses and 430 patients will be clustered into 10 HD units. These units will be randomised into an experimental group (EG) and a waiting-list control group (WLCG). Measurements will be taken at baseline (pre-intervention) and repeatedly over time (post-intervention): immediately at EI completion and six and 12 months thereafter. For the qualitative portion of the study, 18 semi-structured interviews will be conducted with EG nurses picked at random two months after EI completion to explore perceived changes in nurse humanistic practice. Qualitative data will be analysed through the relational caring inquiry method, a phenomenological approach. Descriptive and inferential statistics will be computed from the quantitative data. DISCUSSION: The study described in this protocol will determine if and how the proposed EI promotes humanistic nursing practice and how this practice affects quality of NPR, nurse QoWL, and patient QoL. Moreover, it will lay the groundwork for offering the EI to nurses in other healthcare sectors. TRIAL REGISTRATION: This clinical study was registered with ClinicalTrials.gov [NCT03283891, 14/09/2017].

Wrist flexion and extension torques measured by highly sensitive dynamometer in healthy subjects from 5 to 80 years.

BACKGROUND: Wrist movements become impaired with disease progression in various neuromuscular disorders. With the development of new therapies, thorough measurement of muscle strength is crucial to document natural disease progression and to assess treatment efficacy. We developed a new dynamometer enabling wrist flexion and extension torque measurement with high sensitivity. The aims of the present study were to collect norms for healthy children and adults, to compute predictive equations, to assess the reliability of the measurements and to test the feasibility of using the device in patients with a neuromuscular disease. METHODS: The peak isometric torque of wrist flexion and extension was measured with the MyoWrist dynamometer in 345 healthy subjects aged between 5 and 80 years old and in 9 patients with limb girdle muscle dystrophy type 2 C (LGMD2C) aged between 16 and 38 years old. RESULTS: Predictive equations are proposed for the wrist flexion and extension strength in children and adults. Intra-rater and inter-rater reliability was good with ICCs higher than 0.9 for both wrist flexion and extension. However, retest values were significantly higher by 4% than test results. The dynamometer was applied with no difficulty to patients with LGMD2C and was sensitive enough to detect strength as weak as 0.82 N.m. From our models, we quantified the mean strength of wrist extension in LGMD2C patients to 39 ± 17% of their predicted values. CONCLUSIONS: The MyoWrist dynamometer provides reliable and sensitive measurement of both wrist flexion and extension torques. However, a training session is recommended before starting a study as a small but significant learning effect was observed. Strength deficit can be quantified from predictive equations that were computed from norms of healthy children and adults.

Measuring Health Care Work-Related Contextual Factors: Development of the McGill Context Tool.

INTRODUCTION: Contextual factors can influence healthcare professionals' (HCPs) competencies, yet there is a scarcity of research on how to optimally measure these factors. The aim of this study was to develop and validate a comprehensive tool for HCPs to document the contextual factors likely to influence the maintenance, development, and deployment of professional competencies. METHODS: We used DeVellis' 8-step process for scale development and Messick's unified theory of validity to inform the development and validation of the context tool. Building on results from a scoping review, we generated an item pool of contextual factors articulated around five themes: Leadership and Agency, Values, Policies, Supports, and Demands. A first version of the tool was pilot tested with 127 HCPs and analyzed using the classical test theory. A second version was tested on a larger sample (n = 581) and analyzed using the Rasch rating scale model. RESULTS: First version of the tool: we piloted 117 items that were grouped as per the themes related to contextual factors and rated on a 5-point Likert scale. Cronbach alpha for the set of 12 retained items per scale ranged from 0.75 to 0.94. Second version of the tool included 60 items: Rasch analysis showed that four of the five scales (ie, Leadership and Agency, Values, Policies, Supports) can be used as unidimensional scales, whereas the fifth scale (Demands) had to be split into two unidimensional scales (Demands and Overdemands). DISCUSSION: Validity evidence documented for content and internal structure is encouraging and supports the use of the McGill context tool. Future research will provide additional validity evidence and cross-cultural translation.

The first hexadithienylethene-substituted tris(bipyridine)metal complexes as quadratic NLO photoswitches: combined experimental and DFT studies.

Flip the NLO switch! A straightforward access to hexadithienylethene-based photochromes by using a coordination-chemistry approach through the combination of bis(dithienylethene)bipyridyl ligands and metal ions (M = Zn, Fe) is reported. The photostability of the isomeric forms of the iron(II) complexes allows the photoswitching of second-order nonlinear optical (NLO) responses (see figure), and the results are rationalized with the help of time-dependent density functional theory.

Ankle dorsi- and plantar-flexion torques measured by dynamometry in healthy subjects from 5 to 80 years.

BACKGROUND: Ankle strength is often impaired in some of the most common neuromuscular disorders. Consequently, strength generated around this joint is important to assess, because it has a great impact on balance and gait. The objectives of this study were to establish normative data and predictive equations for both ankle dorsi- and plantar-flexion strength from a population of healthy subjects (children and adults), to assess the reliability of the measurements and to study the feasibility of using a novel dynamometer on a group of patients with a neuromuscular disorder. METHODS: Measurements of maximal isometric torque for dorsi- and plantar-flexion were performed on 345 healthy subjects from 5 to 80 years of age. The feasibility of the method was tested on nine patients diagnosed with type 2A limb girdle muscular dystrophy. RESULTS: The results documented normal strength values depending on gender and age on ankle dorsi- and plantar-flexion. The reliability of the technique was good with no evaluator effect and a small learning effect. The dynamometer was found suitable in the group of patients, even very weak. CONCLUSIONS: The device developed was both reliable and accurate in assessing both ankle dorsi-flexion and plantar-flexion torque measurements from weak patients and children to strong healthy adults. Norms and predictive equations are provided for these two muscle functions.

Photochromic metal complexes: photoregulation of both the nonlinear optical and luminescent properties.

A series of dithienylethene (DTE)-containing 2,2'-bipyridine ligands and their zinc(II) diacetate, zinc(II) dichloro, rhenium(I) tricarbonyl bromo, and ruthenium(II) bis(bipyridine) complexes have been designed and synthesized, and their photochromic, photophysical, and quadratic nonlinear optical properties have been studied. Upon UV irradiation at 350 nm, the ligands and complexes undergo ring closure of the DTE units, with a good to excellent photocyclization yield. In the case of the Re(I) and Ru(II) complexes, the photocyclization of the DTE units can also be triggered using visible light, upon excitation into the metal-to-ligand charge-transfer (MLCT) bands at 400 and 490 nm, respectively. Molecular quadratic nonlinear optical (NLO) responses of the complexes have been determined by using either the electrical field induced second harmonic generation (EFISH) or harmonic light scattering (HLS) technique at 1910 nm. These studies reveal a large increase of the second-order NLO activity after UV irradiation and subsequent formation of the ring-closed isomers. This efficient enhancement clearly reflects the delocalization of the π-electron system and the formation of strong push-pull chromophores in the closed forms. The combination of the photochromic DTE-based bipyridine ligand with luminescent Re(I) and Ru(II) fragments also allows the photoregulation of the emission, leading to an efficient quenching of the ligand-based 77 K luminescence and demonstrating that the photocontrol of two optical properties, linear and nonlinear, could be achieved by using the same photochromic ligand.

Synthesis and NLO properties of new trans 2-(thiophen-2-yl)vinyl heteroaromatic iodides.

The synthesis and characterisation of new trans 2-(thiophen-2-yl)vinyl pyridinium, imidazolium and quinoilinium iodides is reported together with their solvatochromic shifts and EFISH characterization. 2-{(E)-2-[5'-(dibutylamino)-2,2'-bithien-5-yl]vinyl}-1-methyl pyridinium and quinolinium iodides display high µ.ß(vec) values up to 1200 × 10(-48) esu. The promising non-linear optical (NLO) properties of this new family of chromophores, which can be further improved by the design of highly efficient systems exploiting the donor and acceptor properties of both heteroaromatic rings and substituents, make them suitable candidates for second harmonic generation imaging with interesting biological applications.

Upper limb disease evolution in exon 53 skipping eligible patients with Duchenne muscular dystrophy.

OBJECTIVE: To understand the natural disease upper limb progression over 3 years of ambulatory and non-ambulatory patients with Duchenne muscular dystrophy (DMD) using functional assessments and quantitative magnetic resonance imaging (MRI) and to exploratively identify prognostic factors. METHODS: Forty boys with DMD (22 non-ambulatory and 18 ambulatory) with deletions in dystrophin that make them eligible for exon 53-skipping therapy were included. Clinical assessments, including Brooke score, motor function measure (MFM), hand grip and key pinch strength, and upper limb distal coordination and endurance (MoviPlate), were performed every 6 months and quantitative MRI of fat fraction (FF) and lean muscle cross sectional area (flexor and extensor muscles) were performed yearly. RESULTS: In the whole population, there were strong nonlinear correlations between outcome measures. In non-ambulatory patients, annual changes over the course of 3 years were detected with high sensitivity standard response mean (|SRM| ≥0.8) for quantitative MRI-based FF, hand grip and key pinch, and MFM. Boys who presented with a FF<20% and a grip strength >27% were able to bring a glass to their mouth and retained this ability in the following 3 years. Ambulatory patients with grip strength >35% of predicted value and FF <10% retained ambulation 3 years later. INTERPRETATION: We demonstrate that continuous decline in upper limb strength, function, and MRI measured muscle structure can be reliably measured in ambulatory and non-ambulatory boys with DMD with high SRM and strong correlations between outcomes. Our results suggest that a combination of grip strength and FF can be used to predict important motor milestones.

Effects of the metal center and substituting groups on the linear and nonlinear optical properties of substituted styryl-bipyridine metal(II) dichloride complexes: DFT and TDDFT computational investigations and harmonic light scattering measurements.

UV-visible absorption spectroscopy and harmonic light scattering measurements coupled with density functional theory (DFT) calculations have been carried out for a series of 4,4'-bis(X-styryl)-2,2'-bipyridine M(II) dichloride complexes (M = Co, Ni, Cu, Zn; X = H, OMe, SMe, NMe(2), NEt(2), CN, NO(2)). The roles of the metal and the substituent X on their coordination geometries, absorption, and quadratic nonlinear optical properties have been investigated. We show that these complexes all exhibit a high-spin configuration and display a distorted tetrahedral metallic environment except the copper ones, which are distorted square-planar complexes. When X is a strong electron-donating group (X = NMe(2), NEt(2)), TDDFT calculations clearly demonstrate that, whereas the Zn complexes show an ILCT transition in the visible range, the Co, Ni, and Cu complexes exhibit additional MLCT and LLCT transitions. These latter transitions are vectorially opposed to the ILCT and could contribute to the decrease of the experimental quadratic hyperpolarizability beta values, in the order Zn > Ni approximately Cu > Co. The computation of the beta values using TDDFT for the whole series of the closed-shell Zn(II) complexes featuring different X substituents established that the NLO activity increases with the donating strength of X and more generally with the decrease of the HOMO-LUMO energy gap. When X is a strong withdrawing group, the drastic decrease of the NLO response is explained by the negligible participation of the HOMO-LUMO transitions.

Wideband tunable microwave signal generation in a silicon-micro-ring-based optoelectronic oscillator.

Si photonics has an immense potential for the development of compact and low-loss opto-electronic oscillators (OEO), with applications in radar and wireless communications. However, current Si OEO have shown a limited performance. Si OEO relying on direct conversion of intensity modulated signals into the microwave domain yield a limited tunability. Wider tunability has been shown by indirect phase-modulation to intensity-modulation conversion. However, the reported tuning range is lower than 4 GHz. Here, we propose a new approach enabling Si OEOs with wide tunability and direct intensity-modulation to microwave conversion. The microwave signal is created by the beating between an optical source and single sideband modulation signal, selected by an add-drop ring resonator working as an optical bandpass filter. The tunability is achieved by changing the wavelength spacing between the optical source and a resonance peak of the resonator. Based on this concept, we experimentally demonstrate microwave signal generation between 6 GHz and 18 GHz, the widest range for a Si-micro-ring-based OEO. Moreover, preliminary results indicate that the proposed Si OEO provides precise refractive index monitoring, with a sensitivity of 94350 GHz/RIU and a potential limit of detection of only 10-8 RIU, opening a new route for the implementation of high-performance Si photonic sensors.

A comparative descriptive analysis of perceived quality of caring attitudes and behaviours between haemodialysis patients and their nurses.

Aim: Despite its importance in nursing, perceived quality of the nurse-patient relationship has seldom been researched. This study sought to examine and compare the quality of caring attitudes and behaviours as perceived by haemodialysis patients and their nurses. Design: This comparative descriptive study involved 140 haemodialysis patients and 101 nurses caring for them in ten haemodialysis units in the French-speaking part of Switzerland. Methods: Participants completed a sociodemographic questionnaire and the Caring Nurse-Patient Interaction Scale (CNPI-70). Results: Both nurses and patients reported a high frequency of caring attitudes and behaviours. Patients gave higher ratings than nurses did on all the caring dimensions, except spirituality. Implications are discussed.

Normalized grip strength is a sensitive outcome measure through all stages of Duchenne muscular dystrophy.

OBJECTIVE: The main aim was to explore the changes in hand-grip strength in patients with Duchenne muscular dystrophy (DMD) aged 5-29 years. Secondary aims were to test the effect of mutation, ambulatory status and glucocorticoid use on grip strength and its changes over time and to compute the number of subjects needed for a clinical trial to stabilize grip strength. METHODS: The analysis was performed on data collected during five international natural history studies on a cohort of DMD patients. Two hundred and two patients with genetically proven DMD were pooled from five different natural history studies. Excepting 13 patients with only one visit, the mean duration of follow-up was 2.2 ± 1.6 years. A total of 977 measurement points were collected. Grip strength was measured on the dominant side with a high precision dynamometer. The analysis was performed using absolute values and normalized values expressed in percentage of predicted values for age. RESULTS: For absolute values, grip strength typically increased in ambulatory boys and decreased in non-ambulatory patients. However, when normalized, grip strength was already reduced at age 5 years and thereafter continued to fall away from normal values. The weaker the patients, the less strength they are prone to lose over again. INTERPRETATION: Grip strength constitutes a sensitive and continuous outcome measure that can be used across all stages of DMD. Its measurement is easy to standardized, can be used in ambulatory and non-ambulatory patients and does not present any floor or ceiling effect. It is thus attractive as an outcome measure in therapeutic trials.

Synthesis, characterization and third-order nonlinear optical properties of a dodecaruthenium organometallic dendrimer with a zinc(ii) tetraphenylporphyrin core.

A new Zn(ii) porphyrin-based dendrimer (52) containing twelve Ru(ii) alkynyl fragments, has been prepared following a convergent approach in two steps from 5,10,15,20-tetra(4-ethynylphenyl)porphyrinatozinc(ii) (6). The cubic nonlinear optical (NLO) properties of 52 and other derivatives of 6 have been measured by third-harmonic generation (THG) at 1907 nm and by Z-scan over the spectral range 500-1700 nm, revealing the remarkable NLO response of 52 in the near-IR range. These results highlight the beneficial role of the extended "cross fourchée"-like polymetallic structure of 52 on its third-order NLO properties.

Isokinetic muscle testing for weak patients suffering from neuromuscular disorders: a reliability study.

Precise, sensitive muscle strength testing methods are needed to investigate muscle function in patients with neuromuscular disorders (NMD). Here, we describe an isokinetic knee flexor and extensor testing procedure using the Biodex 3's continuous passive motion (CPM) mode. The torque values recorded during passive isokinetic motion were subtracted from the torque values obtained for the same movement with maximal, concentric effort. The aims of the present study were to (i) evaluate the method's reliability in NMD patients presenting mild to severe muscle weakness and (ii) study the relationship between manual muscle testing (MMT) and isokinetic dynamometry. The fifteen participating patients were tested twice; the respective intraclass correlation coefficients (ICCs) for the two sessions ranged from 0.91 to 0.99 for the peak torque, work and power and from 0.50 to 0.90 for the angle at peak torque. The Spearman rho correlation coefficients comparing isokinetic values and MMT values ranged from 0.67 to 0.74 (p<0.01). This reliable, dynamic method appears to be of great value in NMD evaluation when sensitive strength measurement at the knee is required.

Relationships between grip strength, myotonia, and CTG expansion in myotonic dystrophy type 1.

In myotonic dystrophy type 1, several studies have suggested causal relationships between CTG repeat length and the severity of symptoms, such as weakness or myotonia. We aimed to explore these relationships in a large population of 144 DM1 patients. All patients underwent clinical and functional assessments using a standardized test for grip strength and myotonia assessment. Myotonia was assessed using a fully automatic software based on mathematical modeling of relaxation force curve. CTG repeat length was statistically correlated with both myotonia and grip strength, which are two major primary neuromuscular symptoms of DM1 patients. However, these relationships are not clinically meaningful and not predictive at the individual level.

The diagnostic value of hyperammonaemia induced by the non-ischaemic forearm exercise test.

AIMS: The non-ischaemic forearm exercise test (NIFET) is used as a diagnostic tool for the screening of patients with exercise intolerance and for the diagnosis of various metabolic muscle disorders. The production of lactate and ammonia are generally analysed to guide the diagnosis. The aim of this retrospective study was to determine the level of ammonia rise, which can be suggestive of a muscle disease. METHODS: This retrospective study involved 1440 patients who underwent NIFET. The clinical files of the patients with hyperammonaemia were methodically studied. Normal values were derived from 60 healthy controls. RESULTS: 110 patients with hyperammonaemia were detected. They were classified as either having mild (between 94 and 141 µmol/L) or severe (more than 141 µmol/L) hyperammonaemia. Their diagnosis was studied with respect to the increase in lactate induced by the NIFET. CONCLUSIONS: Severe postexercise hyperammonaemia, even in the presence of a normal lactate response, is strongly suggestive of a muscle glycogen storage disease. Mild hyperammonaemia in the absence of other abnormalities is most likely non-specific and not indicative of a muscle disease.