[The effect of continuous peri-thoracic negative pressure on nocturnal desaturation of chronic obstructive bronchopneumopathies].
The fall of functional residual capacity (FRC) in the genesis of nocturnal desaturation in chronic airflow obstruction (COPD) continues to be discussed. This hypothesis is being tested by applying a negative continuous thoracic pressure using a cuirass/poncho attached to a pump for one night (night II) after a control night with a cuirass/poncho at atmospheric pressure (night 1). Seven subjects with a mean age of 61 +/- 9, with a mean weight of 108 +/- 21% of their ideal weight, who were suffering from severe airflow obstruction with a mean forced expired volume (FEV1: 39 +/- 20% th., FEV1/FVC: 35 +/- 9%, PaO2: 60 +/- 3 mmHg, PaCO2: 42 +/- 4 mmHg). These seven subjects had two polysomnographies on the two successive nights. During night II, the FRC was increased by 0.33 +/- 0.6 L by applying a continuous negative thoracic pressure of 10 +/- 1 cm of water. A significant decrease in the sleep time was noted (248 +/- 86 min vs 316 +/- 74 min, p less than 0.02) also the efficacy of sleep (54 +/- 9% vs 71 +/- 15% vm p less than 0.02). There was no difference between the two nights as regards the distribution of the sleep stages. In 2 subjects, the hypopnoea-apnoea index passed from 0 to 11 and from 4 to 22 respectively. The principal result was the absence of any significant difference in mean nocturnal oxygen saturation between the two nights.(ABSTRACT TRUNCATED AT 250 WORDS)
Pison
C
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Département de Médecine, Hôpital du Sacré-Coeur, Université de Montréal, Québec.
Bédard
M A
MA
Malo
J
J
Montplaisir
J
J
D005260:Female; D005652:Functional Residual Capacity / Q000502:physiology; D006801:Humans; D006935:Hypercapnia / Q000503:physiopathology; D000860:Hypoxia / Q000503:physiopathology; D008173:Lung Diseases, Obstructive / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption / Q000502:physiology*; D012115:Residual Volume / Q000502:physiology; D012890:Sleep / Q000502:physiology; D014109:Total Lung Capacity / Q000502:physiology; D015919:Ventilators, Negative-Pressure; D014797:Vital Capacity / Q000502:physiology
D010100:Oxygen
Effets d'une pression négative périthoracique continue sur les désaturations nocturnes des bronchopneumopathies chroniques obstructives.