title: Closed system endotracheal suctioning maintains lung volume during volume-controlled mechanical ventilation.
abstract: OBJECTIVE
  A closed suction system (CS) maintains connection with the mechanical ventilator during tracheal suctioning and is claimed to limit loss in lung volume and oxygenation. We compared changes in lung volume, oxygenation, airway pressure and hemodynamics during endotracheal suctioning performed with CS and with an open suction system (OS).
  
  
  METHODS
  Prospective, randomized study.
  
  
  METHODS
  Intensive care unit in a university hospital.
  
  
  METHODS
  We enrolled ten patients, volume-controlled (VC) ventilated with a Siemens Servo 900 ventilator (PaO2/FIO2 192 +/- 70, PEEP 10.7 +/- 3.9 cmH2O).
  
  
  METHODS
  We performed four consecutive tracheal suction maneuvers, two with CS and two with OS, at 20-min intervals. During the suction maneuvers continuous suction was applied for 20 s.
  
  
  RESULTS
  We measured end-expiratory lung volume changes (delta VL), tidal volume (VTrt), respiratory rate (RR) and minute volume (VErt) by respiratory inductive plethysmography; arterial oxygen saturation (SpO2), airway pressure and arterial pressure (PA). Loss in lung volume during OS (delta VL 1.2 +/- 0.7 l) was significantly higher than during CS (delta VL 0.14 +/- 0.1 l). During OS we observed a marked drop in SpO2, while during CS the change was only minor. During CS ventilation was not interrupted and we observed an immediate increase in RR (due to the activation of the ventilator's trigger), while VTrt decreased, VErt was maintained.
  
  
  CONCLUSIONS
  Avoiding suction-related lung volume loss can be helpful in patients with an increased tendency to alveolar collapse; CS allows suctioning while avoiding dramatic drops in lung volumes and seems to be safe during the VC ventilation setting that we used.
authors.affiliation: Department of Anesthesia and Intensive Care, Ospedale S. Gerardo dei Tintori, University of Milan-Bicocca, via Donizetti 106, Monza, MI, 20052 Italy.
authors.forename: M
authors.initials: M
authors.lastname: Cereda
authors.forename: F
authors.initials: F
authors.lastname: Villa
authors.forename: E
authors.initials: E
authors.lastname: Colombo
authors.forename: G
authors.initials: G
authors.lastname: Greco
authors.forename: M
authors.initials: M
authors.lastname: Nacoti
authors.forename: A
authors.initials: A
authors.lastname: Pesenti
mesh_terms: D000328:Adult; D000368:Aged; D000403:Airway Resistance / Q000502:physiology; D001784:Blood Gas Analysis; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007362:Intensive Care Units; D007442:Intubation, Intratracheal; D008168:Lung / Q000503:physiopathology*; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D010993:Plethysmography, Whole Body; D011446:Prospective Studies; D012121:Respiration, Artificial; D012128:Respiratory Distress Syndrome / Q000097:blood / Q000503:physiopathology* / Q000628:therapy*; D013396:Suction