The effects of different weaning modes on stress response
© BioMed Central Ltd 2003
Published: 3 March 2003
The aim of this study was to compare the effects of different weaning modes (pressure support ventilation [PSV], continuous positive airway pressure [CPAP], T-piece) on stress response in humans.
The study was performed on 60 patients, which were mechanically ventilated for 2 days or more and had inclusion weaning criteria in ICU. After taking the initial blood samples for cortisol, insulin and glucose values and urine samples for vanilmandelic acid (VMA) value measurement, patients were randomly divided into three groups (n = 20). In group 1, the patients ventilated with PSV, with FiO2 < 0.4, level of support < 10 cmH2O, PEEP < 5 cmH2O, parameters for 2 hours. In group 2, the patients received 5 cmH2O CPAP via endotracheal tube for 2 hours. In group 3, the patients received 4 l/min oxygen via T-piece for 2 hours. At the end of the 2 hours and after 48 hours of extubation, blood and urine samples were taken for aforementioned measurements. Weaning was considered successful if reintubation was not required within 48 hours of extubation.
Insulin, cortisol and urine VMA values of group 3 were higher than of groups 1 and 2, after 48 hours of the extubation (P < 0.01, P < 0.05, P < 0.05, respectively). Blood glucose values of group 3 were lower than those of groups 2 and 1 after 48 hours of extubation (P < 0.01, P < 0.01, respectively).
The T-piece device had a higher stress response than PSV and CPAP modes after weaning off mechanical ventilation.