Lung computed tomography during a lung recruitment maneuver in patients with acute lung injury

Intensive Care Med. 2003 Feb;29(2):218-25. doi: 10.1007/s00134-002-1618-6. Epub 2003 Jan 18.


Objective: To assess the acute effect of a lung recruitment maneuver (LRM) on lung morphology in patients with acute lung injury (ALI) or acute respiratory distress syndrome (ARDS).

Patients: Ten patients with ALI/ARDS on mechanical ventilation.

Design: Prospective clinical study.

Setting: Computed tomography (CT) scan facility in a teaching hospital.

Interventions: An LRM performed by stepwise increases in positive end-expiratory pressure (PEEP) of up to 30-40 cm H(2)O. Lung basal CT sections were taken at end-expiration (patients 1 to 5), and at end-expiration and end-inspiration (patients 6 to 10). Arterial blood gases and static compliance (C(st)) were measured before, during and after the LRM.

Measurements and main results: Poorly aerated and non-aerated tissue at PEEP 10 cm H(2)O accounted for 60.0+/-29.1% of lung parenchyma, while only 1.1+/-1.8% was hyperinflated. Increasing PEEP to 20 and 30 cm H(2)O, compared to PEEP 10 cm H(2)O, decreased poorly aerated and non-aerated tissue by 16.2+/-28.0% and 33.4+/-13.8%, respectively ( p<0.05). This was associated with an increase in PaO(2) and a decrease in total static compliance. Inspiration increased alveolar recruitment at all PEEP levels. Hyperinflated tissue increased up to 2.9+/-4.0% with PEEP 30 cm H(2)O, and to a lesser degree with inspiration. No barotrauma or severe hypotension occurred.

Conclusions: Lung recruitment maneuvers improve oxygenation by expanding collapsed alveoli without inducing too much hyperinflation in ALI/ARDS patients. An LRM during the CT scan gives morphologic and functional information that could be useful in setting ventilatory parameters.

MeSH terms

  • Adult
  • Aged
  • Airway Resistance
  • Blood Gas Analysis
  • Clinical Protocols
  • Female
  • Humans
  • Lung Compliance
  • Male
  • Middle Aged
  • Positive-Pressure Respiration / methods*
  • Prospective Studies
  • Pulmonary Alveoli / physiopathology
  • Radiography, Interventional / methods*
  • Respiratory Distress Syndrome / diagnostic imaging*
  • Respiratory Distress Syndrome / metabolism
  • Respiratory Distress Syndrome / physiopathology
  • Respiratory Distress Syndrome / therapy*
  • Respiratory Mechanics
  • Tidal Volume
  • Time Factors
  • Tomography, X-Ray Computed / methods*
  • Treatment Outcome