title: Frequency of mechanical ventilation and respiratory activity after double lung transplantation.
abstract: We investigated the contribution of pulmonary afferent nerve fibers to the control of inspiratory activity in awake humans. Eight double lung transplant outpatients and eight normal subjects were hyperventilated with a mechanical ventilator. Respiratory frequency was increased until no respiratory activity was detectable. Then, by either adding CO2 in the inspired gas or decreasing respiratory frequency, end-tidal PCO2 (PETCO2) was increased until inspiratory activity (i.e. change in inspiratory airway pressure peak and/or time profile) was detected. In normal subjects, PETCO2 threshold for inspiratory muscle recruitment was significantly lower when frequency was decreased than when CO2 was added (31.3 +/- 6.8 Torr vs. 38.2 +/- 8.1 Torr respectively, P < 0.005). This was not the case in the double lung transplant group (31.5 +/- 6.5 Torr vs. 32.9 +/- 5.8 Torr). These findings suggest that pulmonary afferent nerves have an inhibitory effect on inspiratory activity in humans.
authors.affiliation: Service de Pneumologie, Hôpital Antoine Béclère, Clamart, France.
authors.forename: F
authors.initials: F
authors.lastname: Lofaso
authors.forename: G
authors.initials: G
authors.lastname: Simonneau
authors.forename: F L
authors.initials: FL
authors.lastname: Ladurie
authors.forename: J
authors.initials: J
authors.lastname: Cerrina
authors.forename: A
authors.initials: A
authors.lastname: Chapelier
authors.forename: F
authors.initials: F
authors.lastname: Brenot
authors.forename: P
authors.initials: P
authors.lastname: Dartevelle
authors.forename: P
authors.initials: P
authors.lastname: Herve
mesh_terms: D000328:Adult; D002245:Carbon Dioxide; D005260:Female; D006801:Humans; D016040:Lung Transplantation; D008297:Male; D008875:Middle Aged; D010313:Partial Pressure; D011184:Postoperative Period; D012016:Reference Values; D012119:Respiration; D012121:Respiration, Artificial; D013147:Spirometry
chemical_list: D002245:Carbon Dioxide