Efeito da ventilação não invasiva na distrofia muscular de Duchenne

Bélgica e Reino Unido - 50 pacientes com Duchenne foram acampanhados; os pacientes que apresentavam hipoventilação noturna receberam a ventilação não invasiva durante a noite; os que apresentavam falta de ar recebiam adicionalmente a ventilação não invasiva diurna por duas horas no período da tarde. Os resultados demonstraram que os pacientes com o uso da ventilação não invasiva diurna por duas horas tiveram melhora do desempenho respiratório do que o observado somente com o uso da ventilação noturna. Apesar de não cumprida na maioria dos estados no Brasil, uma portaria do Ministério da Saúde garante o uso aos portadores de distrofia muscular que necessitarem da ventilação não invasiva pelo SUS.

O resumo em inglês do artigo pode ser lido abaixo:

(Thorax, May 2008; 63: 430 - 434) Effect of non-invasive ventilation on respiratory muscle loading and endurance in patients with Duchenne muscular dystrophy

M Toussaint1, P Soudon1, W Kinnear2 1 Centre for Home Mechanical Ventilation, Ziekenhuis Inkendaal, Vlezenbeek, Belgium
2 Department of Respiratory Medicine, University Hospital, Nottingham, UK

Background: Respiratory muscle weakness in patients with Duchenne muscular dystrophy (DMD) leads to respiratory failure for which non-invasive positive pressure ventilation (NIPPV) is an effective treatment. This is used initially at night (n-NIPPV) but, as the disease progresses, diurnal use (d-NIPPV) is often necessary. The connection between NIPPV and relief of respiratory muscle fatigue remains unclear. A study was undertaken to determine the extent to which n-NIPPV and d-NIPPV unload the respiratory muscles and improve respiratory endurance in patients with DMD.

Methods: Fifty patients with DMD were assessed at 20.00 and 08.00 h. More severely affected patients with nocturnal hypoventilation received n-NIPPV; those with daytime dyspnoea also received d-NIPPV via a mouthpiece (14.00–16.00 h). Lung function, modified Borg dyspnoea score, spontaneous breathing pattern, tension-time index (TT0.1 = occlusion pressure (P0.1)/maximum inspiratory pressure (MIP) x duty cycle (Ti/Ttot)) and respiratory muscle endurance time (Tlim) against a threshold load of 35% MIP were measured.

Results: More severe respiratory muscle weakness was associated with a higher TT0.1 and lower Tlim. In contrast to non-dyspnoeic patients, patients with dyspnoea (Borg score >2.5/10) showed an increase in Tlim and decrease in TT0.1 after n-NIPPV. At 16.00 h, immediately after d-NIPPV, patients with dyspnoea had lower TT0.1 and Borg scores with unchanged Tlim. Compared with the control day without d-NIPPV, TT0.1, Borg scores and Tlim were all improved at 20.00 h.

Conclusions: In patients with dyspnoea with DMD, the load on respiratory muscles increases and endurance capacity decreases with increasing breathlessness during the day, and this is reversed by n-NIPPV. An additional 2 h of d-NIPPV unloads respiratory muscles and reverses breathlessness more effectively than n-NIPPV alone.

Fonte: http://distrofiamuscular.net/noticias.htm