PT - JOURNAL ARTICLE AU - DO Rodenstein AU - DC Stanescu AU - P Delguste AU - G Liistro AU - G Aubert-Tulkens TI - Adaptation to intermittent positive pressure ventilation applied through the nose during day and night AID - 10.1183/09031936.93.02050473 DP - 1989 May 01 TA - European Respiratory Journal PG - 473--478 VI - 2 IP - 5 4099 - http://erj.ersjournals.com/content/2/5/473.short 4100 - http://erj.ersjournals.com/content/2/5/473.full SO - Eur Respir J1989 May 01; 2 AB - A 49 yr old poliomyelitic patient had been under cuirass-type nocturnal negative pressure ventilation for more than 20 yrs. He had a severe restrictive ventilatory impairment, and normal awake blood gases at rest and during light exercise. He was offered a trial of intermittent positive pressure ventilation applied through the nose (nIPPV). Two daytime studies and one night study were carried out under nIPPV, and one night study was performed under negative pressure ventilation. Tidal volume, respiratory frequency (Respitrace), blood gases and electromyogram (EMG) of the diaphragm (DEMG, oesophageal electrode) and/or sternocleidomastoid (ScEMG, surface electrodes) were measured. During daytime studies under nIPPV, the DEMG (and/or the ScEMG) did not decrease by more than 25% (p less than 0.005). However, when the patient was encouraged to relax, the DEMG decreased by 62% (p less than 0.001). Tidal volume and ventilation significantly increased during daytime nIPPV (p less than 0.025), whereas blood gases were kept at physiological levels. At night, the ScEMG was present and prominent until sleep onset. Thereafter it disappeared and remained silent, including periods of wakefulness during sleep time, until final awakening in the morning. This was true for both negative pressure ventilation and nIPPV. Snoring was present throughout sleep under negative pressure ventilation but not under nIPPV. We conclude that the behavioural response of the subject may determine the electrical activity of respiratory muscles during assisted ventilation.