title: Effects of controlled and pressure support mechanical ventilation on rat diaphragm muscle.
abstract: OBJECTIVE
  The objective of this study was to analyze the effects of Pressure Controlled Ventilation mode (PCV-C) and PSV mode in diaphragm muscle of rats.
  
  
  METHODS
  Wistar rats (n=18) were randomly assigned to the control group or to receive 6 hours of PCV and PSV. After this period, animals were euthanized and their diaphragms were excised, frozen in liquid nitrogen and stored in at -80º C for further histomorphometric analysis.
  
  
  RESULTS
  Results showed a 15% decrease in cross-sectional area of muscle fibers on the PCV-C group when compared to the control group (p<0.001) and by 10% when compared to the PSV group (p<0.05). Minor diameter was decreased in PCV-C group by 9% when compared with the control group (p<0.001) and by 6% when compared to the PSV group (p<0.05). When myonuclear area was analyzed, a 16% decrease was observed in the PCV-C group when compared to the PSV group (p<0.05). No significant difference between the groups was observed in myonuclear perimeter (p>0.05).
  
  
  CONCLUSIONS
  Short-term controlled mechanical ventilation seems to lead to muscular atrophy in diaphragm fibers. The PSV mode may attenuate the effects of VIDD.
authors.affiliation: Integrated Colleges of Patos, Brazil. andre.sboliveira@gmail.com
authors.forename: André de Sá Braga
authors.initials: Ade S
authors.lastname: Oliveira
authors.forename: Lívia Bandeira
authors.initials: LB
authors.lastname: Costa
authors.forename: Thiago de Oliveira
authors.initials: Tde O
authors.lastname: Assis
authors.forename: Diógenes Luís da
authors.initials: DL
authors.lastname: Mota
authors.forename: Eduardo Ériko Tenório de
authors.initials: EÉ
authors.lastname: França
authors.forename: José Cândido de
authors.initials: JC
authors.lastname: Araújo Filho
authors.forename: Silvania Tavares Paz
authors.initials: ST
authors.lastname: Rosas
authors.forename: Paloma Lys de
authors.initials: PL
authors.lastname: Medeiros
mesh_terms: D000818:Animals; D001835:Body Weight; D003964:Diaphragm / Q000473:pathology* / Q000503:physiopathology; D023421:Models, Animal; D018485:Muscle Fibers, Skeletal / Q000473:pathology; D009133:Muscular Atrophy / Q000209:etiology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012121:Respiration, Artificial / Q000009:adverse effects / Q000379:methods*; D013997:Time Factors