title: Open and closed-circuit endotracheal suctioning in acute lung injury: efficiency and effects on gas exchange.
abstract: BACKGROUND
  Closed-circuit endotracheal suctioning (CES) is advocated for preventing hypoxemia caused by the loss of lung volume resulting from open endotracheal suctioning (OES). However, the efficiency of CES and OES on tracheal secretion removal has never been compared in patients with acute lung injury. The authors designed a two-part study aimed at comparing gas exchange and efficiency between OES and CES performed at two levels of negative pressure.
  
  
  METHODS
  Among 18 patients with acute lung injury, 9 underwent CES and OES at 3-h intervals in a random order using a negative pressure of -200 mmHg. Nine other patients underwent CES twice using two levels of negative pressure (-200 and -400 mmHg) applied in a random order. After each CES, a recruitment maneuver was performed using 20 consecutive hyperinflations. Tracheal aspirates were weighed after each suctioning procedure. Arterial blood gases were continuously recorded using an intravascular sensor.
  
  
  RESULTS
  Open endotracheal suctioning induced a significant 18% decrease in arterial oxygen tension (Pa(O2)) (range, +13 to -71%) and an 8% increase in arterial carbon dioxide tension (Pa(CO2)) (range, -2 to +16%) that persisted 15 min after the end of the procedure. CES using -200 cm H2O did not change Pa(O2), but tracheal aspirate mass was lower compared with OES (0.6 +/- 1.0 vs. 3.2 +/- 5.1 g; P = 0.03). Increasing negative pressure to -400 cm H2O during CES did not change Pa(O2) but increased the tracheal aspirate mass (1.7 +/- 1.6 vs. 1.0 +/- 1.3 g; P = 0.02).
  
  
  CONCLUSIONS
  Closed-circuit endotracheal suctioning followed by a recruitment maneuver prevents hypoxemia resulting from OES but decreases secretion removal. Increasing suctioning pressure enhances suctioning efficiency without impairing gas exchange.
authors.affiliation: Surgical Intensive Care Unit, Department of Anesthesiology, Bichat-Claude Bernard Hospital, University of Paris VII, Paris, France.
authors.forename: Sigismond
authors.initials: S
authors.lastname: Lasocki
authors.forename: Qin
authors.initials: Q
authors.lastname: Lu
authors.forename: Alfonso
authors.initials: A
authors.lastname: Sartorius
authors.forename: Dominique
authors.initials: D
authors.lastname: Fouillat
authors.forename: Francis
authors.initials: F
authors.lastname: Remerand
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Rouby
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000399:Air Pressure; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal; D008168:Lung / Q000502:physiology; D055370:Lung Injury; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012121:Respiration, Artificial; D013396:Suction
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen