[Hypodynamic respiratory insufficiency. Diagnostic investigation].
Patients with restrictive lung disease, owing to respiratory muscle dysfunction, have no parenchymal involvement. Their vital capacity (VC) and total lung capacity (TLC) are reduced to less than 50% and can lead to pneumonia and nocturnal hypercapnia and hypoxia. Their diffusion capacity is normal. With maximal static mouth pressure (Pimax) < 80 cm H2O and/or Pemax < 100 cm H2O, patients are referred to the national centres. Here, inspiratory muscular insufficiency is confirmed by sniff nasal inspiratory pressure and oesophageal pressure < 70 cm H2O. Expiratory muscular insufficiency is confirmed by a cough peak flow < 3-4 L/sec. and cough gastric pressure < 100 cm H2O. Sleep studies reveal nocturnal hypoventilation. Phrenic nerve stimulation is to be introduced in the diagnostic approach. Twitch mouth or oesophageal pressure < 10 cm H2O and twitch gastric pressure < 7 cm H2O are pathognomonic for neuromuscular respiratory insufficiency.
Wiis
Jørgen
J
H:S Rigshospitalet, Diagnostisk Center, klinik for klinisk fysiologi og nuklearmedicin, og Neurocentret, Respirationscenter Øst.
Mortensen
Jann
J
Jacobsen
Erik
E
D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D007040:Hypoventilation / Q000150:complications / Q000503:physiopathology; D008297:Male; D009135:Muscular Diseases / Q000150:complications / Q000503:physiopathology; D012131:Respiratory Insufficiency / Q000150:complications / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D012132:Respiratory Muscles / Q000503:physiopathology; D013147:Spirometry; D014109:Total Lung Capacity; D014797:Vital Capacity