TY - JOUR
T1 - Pulmonary abnormalities after cardiac surgery are better explained by atelectasis than by increased permeability oedema
AU - Verheij, J
AU - van Lingen, A
AU - Raijmakers, P G H M
AU - Spijkstra, J-J
AU - Girbes, A R J
AU - Jansen, E K
AU - van den Berg, F G
AU - Groeneveld, A B J
PY - 2005/10
Y1 - 2005/10
N2 - BACKGROUND: Cardiac surgery can be complicated by pulmonary abnormalities, but it is unclear how various manifestations interrelate.METHODS: A prospective study in the intensive care unit was performed on 26 mechanically ventilated patients without cardiac failure within 3 h after elective cardiac surgery involving cardiopulmonary bypass. Oedema (extravascular lung water, EVLW) was measured by the thermal-dye technique and permeability by a dual radionuclide technique, yielding a pulmonary leak index (PLI). Radiographic, mechanical and gas exchange features were used to calculate the lung injury score (LIS), ranging between 0 and 4. Evidence for left lower lobe atelectasis was obtained from plain radiographs. The plasma colloid osmotic pressure (COP) was measured by an oncometer.RESULTS: The EVLW (normal, <7 ml/kg) was elevated in 36% of patients and the PLI (normal, <14.1 x 10(-3)/min) in 44%, but the variables did not interrelate directly. Patients with a supranormal EVLW had a lower COP than patients with normal EVLW. The duration of mechanical ventilation was prolonged in patients (20%) with EVLW > 10 ml/kg. There was no difference in EVLW and PLI in patients with LIS < 1 and LIS > 1 (31% of patients). In patients with radiographic evidence for atelectasis (46%), the positive end-expiratory pressure and inspiratory O2 fraction to maintain oxygenation were higher than in those without.CONCLUSIONS: After cardiac surgery, mild pulmonary oedema is relatively common, even in the absence of high filling pressures, and is mainly attributable to a low COP, irrespective of increased permeability in about one-half of patients. It may prolong mechanical ventilation at EVLW > 10 ml/kg. However, pulmonary radiographic and ventilatory abnormalities may result, at least in part, from atelectasis rather than increased permeability oedema.
AB - BACKGROUND: Cardiac surgery can be complicated by pulmonary abnormalities, but it is unclear how various manifestations interrelate.METHODS: A prospective study in the intensive care unit was performed on 26 mechanically ventilated patients without cardiac failure within 3 h after elective cardiac surgery involving cardiopulmonary bypass. Oedema (extravascular lung water, EVLW) was measured by the thermal-dye technique and permeability by a dual radionuclide technique, yielding a pulmonary leak index (PLI). Radiographic, mechanical and gas exchange features were used to calculate the lung injury score (LIS), ranging between 0 and 4. Evidence for left lower lobe atelectasis was obtained from plain radiographs. The plasma colloid osmotic pressure (COP) was measured by an oncometer.RESULTS: The EVLW (normal, <7 ml/kg) was elevated in 36% of patients and the PLI (normal, <14.1 x 10(-3)/min) in 44%, but the variables did not interrelate directly. Patients with a supranormal EVLW had a lower COP than patients with normal EVLW. The duration of mechanical ventilation was prolonged in patients (20%) with EVLW > 10 ml/kg. There was no difference in EVLW and PLI in patients with LIS < 1 and LIS > 1 (31% of patients). In patients with radiographic evidence for atelectasis (46%), the positive end-expiratory pressure and inspiratory O2 fraction to maintain oxygenation were higher than in those without.CONCLUSIONS: After cardiac surgery, mild pulmonary oedema is relatively common, even in the absence of high filling pressures, and is mainly attributable to a low COP, irrespective of increased permeability in about one-half of patients. It may prolong mechanical ventilation at EVLW > 10 ml/kg. However, pulmonary radiographic and ventilatory abnormalities may result, at least in part, from atelectasis rather than increased permeability oedema.
KW - Adult
KW - Aged
KW - Cardiac Surgical Procedures/adverse effects
KW - Cardiopulmonary Bypass
KW - Critical Care
KW - Extravascular Lung Water/physiology
KW - Female
KW - Humans
KW - Lung/diagnostic imaging
KW - Lung Diseases/etiology
KW - Male
KW - Middle Aged
KW - Osmotic Pressure
KW - Permeability
KW - Prospective Studies
KW - Pulmonary Atelectasis/etiology
KW - Pulmonary Edema/etiology
KW - Pulmonary Gas Exchange/physiology
KW - Radiography
KW - Respiratory Function Tests
KW - Capillary Permeability
KW - Capillary Leak Syndrome/diagnosis
KW - Mechanical ventilation
KW - Intensive care unit
KW - Gallium Radioisotopes
U2 - 10.1111/j.1399-6576.2005.00831.x
DO - 10.1111/j.1399-6576.2005.00831.x
M3 - Article
C2 - 16146467
VL - 49
SP - 1302
EP - 1310
JO - Acta Anæsthesiologica Scandinavica
JF - Acta Anæsthesiologica Scandinavica
SN - 0001-5172
IS - 9
ER -