Muscular Respiratory Involvement and Systemic Sclerosis

Poitiers University Hospital52 enrolled

Overview

Dyspnea in systemic sclerosis (ScS) constitute a major factor of functional disability. Intensity of dyspnea is sometimes discordant with objectives data from cardiopulmonary involvements, suggesting unknown additional factors. Diffuse fibrosing myopathy of bad prognosis have been reported in ScS.To now, muscular respiratory involvement has not been evaluated in ScS. Therefore, ScS patients (with or without dyspnea) could have underlying respiratory muscular involvement not detected by current standard of care with pulmonary function tests (PFT). This project is the first, to the best of our knowledge, to assess frequency of respiratory muscular involvement in ScS and to evaluate a screening strategy of this involvement.

Study Type

INTERVENTIONAL

Allocation

Purpose

SCREENING

Masking

NONE

Enrollment

Conditions

Systemic Sclerosis Diaphragm Defect Respiratory Insufficiency Pulmonary Function Test

Interventions

Pulmonary function testDIAGNOSTIC_TEST

Diaphragmatic electromyography with measurement of transdiaphragmatic pressure in cases of dyspnea and/or abnormal pulmonary function test (maximum inspiratory pressure and/or lying/seating low vital capacity ratio)

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Age ≥18 years-old * ScS fulfilling ACR/EULAR 2013 classification criteria and followed in the department of internal medicine of Poitiers University Hospital * Written informatory consent Exclusion Criteria: * Individuals under tutorship or guardianship * Individuals with reinforced protection: minors, judiciary or administrative decision * No affiliation to social insurance * Pregnancy or breastfeeding * Associated neuromuscular disease (myasthenia, degenerative diseases) * Bedridden individuals or with health condition not allowing realization or interpretation of PFT and/or EMG (acute cardiac and/or respiratory failure, pneumopathy) * Individuals with pacemaker and implanted pumps, especially sensing dispositives, as defibrillators ( relative contre-indication to EMG with magnetic stimulation) * Individuals with contre-indication to gastroesophageal probe: INR \>4, oesophageal varices, suspected cardio-facial fracture, oesophageal and/or facial obstacle

Outcomes

Primary Outcomes

Frequency of diaphragmatic involvement among ScS patients with dyspnea and/or with suspected respiratory muscular involvement on pulmonary function tests (PFT)

Number of patients with dyspnea (SADOUL ≥2) and/or with respiratory muscular involvement suspected on PFT (maximum inspiratory pressure (max IP) below definite z-score and/or lying/sitting low vital capacity (LVC) ratio \< 75%) having diaphragmatic muscular involvement confirmed by diaphragmatic electromyography (EMG) (latency \>8.5ms and amplitudes \<0.5mV) by neck electric phrenic stimulation and/or Pdi \<20cmH2O after magnetic stimulation