Physiological effects of meals in difficult-to-wean tracheostomised patients with chronic obstructive pulmonary disease.
OBJECTIVE
To evaluate effects of meals in difficult-to-wean tracheostomised patients with chronic obstructive pulmonary diseases during spontaneous breathing or Inspiratory Pressure Support.


METHODS
Prospective, crossover, randomised, and physiological study.


METHODS
Weaning centre.


METHODS
Sixteen COPD undergoing either decreasing levels of pressure support or increasing periods of spontaneous breathing.


METHODS
Each patient underwent monitoring during a 30-min procedure, during and after meals either under pressure support or spontaneous breathing on two consecutive days. Inductance plethysmography was used to monitor respiratory rate and tidal volume. Tidal volume by a flow transducer, arterial oxygen saturation, pulse rate, end-tidal CO2(,) and dyspnoea by a visual analogue scale were also assessed.


RESULTS
ANOVA analysis showed a significant increase under spontaneous breathing for respiratory rate (P<0.001) and for end tidal CO(2) (P<0.03) induced by the meals. Inspiratory pressure support was associated to significantly greater tidal volume (P<0.001), lower respiratory rate (P<0.032), lower respiratory rate/tidal volume (P<0.001), and lower pulse rate (P<0.047) than spontaneous breathing. Under spontaneous breathing but not under pressure support a statistically worsening in meal-induced dispnoea (P<0.001) was found.


CONCLUSIONS
In tracheostomised difficult-to-wean COPD patients: 1) under unassisted breathing, meals may induce an increase in respiratory rate, end-tidal CO(2), and dyspnoea; 2) inspiratory pressure support ventilation prevents dyspnoea from worsening during meals.
Vitacca
Michele
M
Pulmonary Unit, Weaning Centre, S. Maugeri Foundation IRCCS, Via Pinidolo 23, 25064 Gussago, Italy. mvitacca@fsm.it
Callegari
Giovanna
G
Sarvà
Maria
M
Bianchi
Luca
L
Barbano
Luca
L
Balbi
Bruno
B
Ambrosino
Nicolino
N
D000368:Aged; D000704:Analysis of Variance; D018592:Cross-Over Studies; D004435:Eating / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology* / Q000628:therapy*; D012121:Respiration, Artificial; D014139:Tracheostomy; D015300:Ventilator Weaning