Validation Criteria for PETCO2 Kinetics during the Hyperventilation Provocation Test in the Diagnosis of Idiopathic Hyperventilation Syndrome.

Background: The hyperventilation provocation test (HPTest) is a diagnostic tool for idiopathic hyperventilation syndrome (HVS), encountered in some long-COVID patients. However, interpretation of the HPTest remains unclear regarding the relevant PETCO2 values to focus on and whether subjective symptoms should be considered. This study aimed to re-evaluate objective HPTest results for diagnosing HVS by determining accurate PETCO2 kinetics in two groups of patients previously screened via the Nijmegen questionnaire (NQ). Methods: The kinetics of PETCO2 during the HPTest were mathematically modeled and compared between 37 HVS patients (NQ ≥23/64) and 37 healthy controls (NQ <23/64) matched for gender, age, and body dimensions. AUC values with sensitivity and specificity were calculated, and analysis was monitored in a validation cohort of 152 routine HPTests. Results: A threshold value of a less than 12.8 mmHg increment of PETCO2 at the 5th minute of the recovery phase of the HPTest diagnosed HVS patients with excellent sensitivity (0.92) and specificity (0.84). These results were confirmed in the validation cohort, highlighting the presence of 24% false positives/negatives when diagnosing on the basis of complaints in the NQ. Conclusions: For HVS diagnosis, we suggest considering the HPTest, which can more reliably reflect the mechanisms of CO2 homeostasis and the response of the respiratory center to a stimulus, regardless of the subjective onset of symptoms.

Impact of Bariatric Surgery on Women Aerobic Exercise Capacity.

RATIONALE: Bariatric surgery has a considerable positive effect on weight loss and on metabolic and cardiovascular risks. It has therefore been extensively used this last decade to overcome obesity. However, the impact of this surgery on exercise capacity remains unclear. The aim of this study is to clarify the impact of a surgically induced weight loss on aerobic exercise capacity (VO2max) in a specific middle-aged female population. METHODS: Forty-two women with a body mass index > 40 kg/m2 (age, 42 ± 13 years; weight, 117 ± 15 kg) underwent blood analyses and a cardiopulmonary exercise test (CPET) before and 1 year after bariatric surgery. CPET was performed on a cycloergometer. The first ventilatory threshold (VT1) was measured according to the V-slope method. RESULTS: Absolute VO2max was reduced by 10% after surgery (2.0 ± 0.4 vs 1.8 ± 0.4 l/min, p < 0.01) or increased when corrected for body weight (18 ± 4 vs 23 ± 4 l/min/kg, p < 0.001) or unchanged when expressed as percentage of predicted values (111 ± 21 vs 105 ± 22, p = 0.06). Weight loss did not affect ventilatory or chronotropic response but increased maximal respiratory exchange ratio (RER) (p < 0.001), decreased maximal O2pulse (p < 0.05) and VT1 in milliliters per minute (p < 0.01). By multivariable analysis, decreased absolute VO2max after weight loss was associated with increased maximal RER and reduced maximal O2pulse (p < 0.05, p < 0.01 respectively), possibly related to a muscular mass limitation. CONCLUSIONS: Weight loss induced by bariatric surgery may reduce aerobic capacity in women in relation to muscle mass loss.

Integrated Care for Crohn's Disease: A Plea for the Development of Clinical Decision Support Systems.

Evolution in the management of Crohn's disease [CD] has been characterized by recent paradigm changes. First, new biological therapies induce intestinal healing and full disease control in a substantial number of patients, particularly when introduced early in the disease course. However, they are expensive and associated with potentially severe side effects, raising the question of optimal treatment duration. Secondly, progress in biomarkers and medical imaging performance has enabled better refinement of the definition and prediction of remission or relapse of the disease through monitoring [tight control]. This progress may help to improve tailoring treatment in relation to target ['treat-to target' approach], applying patient-centred and collaborative perspectives, consistent with other chronic disease management. Such an approach requires the integration of a potentially large number of parameters coming from different stakeholders. This integration would be difficult based solely on implementation of classical guidelines and the clinician's intuition. To this end, clinical decision support systems should be developed that integrate a combination of various outcomes to facilitate the treatment decision and to share information between patients, primary care specialists, and health insurance companies or health authorities. This should ease complex therapeutic decisions and serve as a basis for continued research into effectiveness of CD management.

Differential profiles of four groups of children referred to an autism diagnostic service in Belgium: Autism-specific hallmarks.

OBJECTIVE:: This article aims at exploring distinctive hallmarks of autistic disorders compared to other groups presenting mimicking and/or overlapping conditions. METHOD:: The exploratory study involved 196 children with autism, intellectual disability, language impairment and psycho-affective disorders previously referred to an autism diagnostic service. The autism discriminative tool (ADT), a behavioural checklist, was used to compile and analyse the children's profiles based on the clinical information gathered during diagnostic assessments. All samples were compared and analysed separately according to the checklist's four domains. RESULTS:: Children with autism showed greater frequency and severity of impairments on the ADT's social and communication categories. These children also differed from other groups in terms of specific rigid behaviours and high frequency of atypical sensory responses. CONCLUSIONS:: Results illustrate the psychopathology of autism spectrum disorder suspected children referred to a specialized autism diagnostic service, doing so by providing us with specific clinical profiles.