title: PEEP-ZEEP technique: cardiorespiratory repercussions in mechanically ventilated patients submitted to a coronary artery bypass graft surgery.
abstract: BACKGROUND
  The PEEP-ZEEP technique is previously described as a lung inflation through a positive pressure enhancement at the end of expiration (PEEP), followed by rapid lung deflation with an abrupt reduction in the PEEP to 0 cmH2O (ZEEP), associated to a manual bilateral thoracic compression.
  
  
  OBJECTIVE
  To analyze PEEP-ZEEP technique's repercussions on the cardio-respiratory system in immediate postoperative artery graft bypass patients.
  
  
  METHODS
  15 patients submitted to a coronary artery bypass graft surgery (CABG) were enrolled prospectively, before, 10 minutes and 30 minutes after the technique. Patients were curarized, intubated, and mechanically ventilated. To perform PEEP-ZEEP technique, saline solution was instilled into their orotracheal tube than the patient was reconnected to the ventilator. Afterwards, the PEEP was increased to 15 cmH2O throughout 5 ventilatory cycles and than the PEEP was rapidly reduced to 0 cmH2O along with manual bilateral thoracic compression. At the end of the procedure, tracheal suction was accomplished.
  
  
  RESULTS
  The inspiratory peak and plateau pressures increased during the procedure (p < 0.001) compared with other pressures during the assessment periods; however, they were within lung safe limits. The expiratory flow before the procedure were 33 ± 7.87 L/min, increasing significantly during the procedure to 60 ± 6.54 L/min (p < 0.001), diminishing to 35 ± 8.17 L/min at 10 minutes and to 36 ± 8.48 L/min at 30 minutes. Hemodynamic and oxygenation variables were not altered.
  
  
  CONCLUSIONS
  The PEEP-ZEEP technique seems to be safe, without alterations on hemodynamic variables, produces elevated expiratory flow and seems to be an alternative technique for the removal of bronchial secretions in patients submitted to a CABG.
authors.affiliation: Physiotherapy Division, Heart Institute (InCor), University of Sao Paulo Medical School, Sao Paulo, Brazil. marcus@fisiorespiratoria.com.br
authors.forename: Marcus Vinicius
authors.initials: MV
authors.lastname: Herbst-Rodrigues
authors.forename: Vitor Oliveira
authors.initials: VO
authors.lastname: Carvalho
authors.forename: José Otávio Costa
authors.initials: JO
authors.lastname: Auler
authors.forename: Maria Ignez Zanetti
authors.initials: MI
authors.lastname: Feltrim
mesh_terms: D000704:Analysis of Variance; D001980:Bronchi / Q000378:metabolism*; D001026:Coronary Artery Bypass; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007442:Intubation, Intratracheal; D008297:Male; D008875:Middle Aged; D026741:Physical Therapy Modalities; D011175:Positive-Pressure Respiration / Q000379:methods*; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange; D012121:Respiration, Artificial; D015656:Respiratory Mechanics; D013396:Suction