title: [Comparison among three methods to measure the rapid shallow breathing index in patients submitted to weaning from mechanical ventilation].
abstract: OBJECTIVE
  To compare the attainment of the rapid shallow breathing index (IRRS) in modalities PSV 10 cmH2O and PEEP 5 cmH2O (PSV10), CPAP 5 cmH2O (CPAP5) and spontaneous breathing (SB), correlating them with success on failure in the withdrawal of mechanical ventilation (MV).
  
  
  METHODS
  Prospective study including 54 patients in MV > 48 hours, submitted to the IRRS in three ventilatory modalities: PSV10, CPAP5 and SB at the moments before and after T-tube spontaneous breathing. The patients were removed from MV when IRRS was < 105.
  
  
  RESULTS
  There wasn't statistically significant difference between IRRS values at the moments before and after T-tube SB. There was statistically significant difference IRRS value between the modalities CPAP5 and PSV10 (p = 0.008), and between the modalities SB and PSV10 (p = 0.01) at the moment before T-Tube SB and of IRRS value, gotten between CPAP5 and PSV10 (p = 0.01) at the moment after T-tube SB.
  
  
  CONCLUSIONS
  From this sample, it can be observed that IRRS values are overestimated when gotten in modality PSV10. It was also evidenced that there is no need of a 30 min T-tube SB before extubation, when the weaning is performed with the technique of gradual reduction of PSV. This study suggested that IRRS is able to predict weaning success; however it is not able to determine failure when it was < 105. It is recommended that IRRS must be analyzed in association with other predictive weaning parameters.
authors.affiliation: UTI Adulto, UNICAMP.
authors.forename: Lorena de Oliveira
authors.initials: Lde O
authors.lastname: Santos
authors.affiliation: UTI Adulto, UNICAMP.
authors.forename: Maraísa Rodrigues
authors.initials: MR
authors.lastname: Borges
authors.affiliation: Programa de Aprimoramento Profissional da FUNDAP em Fisioterapia em UTI Adulto, FCM, UNICAMP.
authors.forename: Luciana Castilho de
authors.initials: LC
authors.lastname: Figueirêdo
authors.affiliation: FCM, UNICAMP.
authors.forename: Cristina Aparecido Veloso
authors.initials: CA
authors.lastname: Guedes
authors.affiliation: UTI Adulto, UNICAMP.
authors.forename: Bruna Scharlack
authors.initials: BS
authors.lastname: Vian
authors.affiliation: Hospital AC Camargo.
authors.forename: Karina
authors.initials: K
authors.lastname: Kappaz
authors.affiliation: Departamento de Cirurgia, FCM, UNICAMP.
authors.forename: Sebastião
authors.initials: S
authors.lastname: Araújo