Tidal volume lower than 6 ml/kg enhances lung protection: role of extracorporeal carbon dioxide removal.

Abstract

BACKGROUND:

Tidal hyperinflation may occur in patients with acute respiratory distress syndrome who are ventilated with a tidal volume (VT) of 6 ml/kg of predicted body weight develop a plateau pressure (PPLAT) of 28 < or = PPLAT < or = 30 cm H2O. The authors verified whether VT lower than 6 ml/kg may enhance lung protection and that consequent respiratory acidosis may be managed by extracorporeal carbon dioxide removal.

METHODS:

PPLAT, lung morphology computed tomography, and pulmonary inflammatory cytokines (bronchoalveolar lavage) were assessed in 32 patients ventilated with a VT of 6 ml/kg. Data are provided as mean +/- SD or median and interquartile (25th and 75th percentile) range. In patients with 28 < or = PPLAT < or = 30 cm H2O (n = 10), VT was reduced from 6.3 +/- 0.2 to 4.2 +/- 0.3 ml/kg, and PPLAT decreased from 29.1 +/- 1.2 to 25.0 +/- 1.2 cm H2O (P < 0.001); consequent respiratory acidosis (Paco2 from 48.4 +/- 8.7 to 73.6 +/- 11.1 mmHg and pH from 7.36 +/- 0.03 to 7.20 +/- 0.02; P < 0.001) was managed by extracorporeal carbon dioxide removal. Lung function, morphology, and pulmonary inflammatory cytokines were also assessed after 72 h.

RESULTS:

Extracorporeal assist normalized Paco2 (50.4 +/- 8.2 mmHg) and pH (7.32 +/- 0.03) and allowed use of VT lower than 6 ml/kg for 144 (84-168) h. The improvement of morphological markers of lung protection and the reduction of pulmonary cytokines concentration (P < 0.01) were observed after 72 h of ventilation with VT lower than 6 ml/kg. No patient-related complications were observed.

CONCLUSIONS:

VT lower than 6 ml/Kg enhanced lung protection. Respiratory acidosis consequent to low VT ventilation was safely and efficiently managed by extracorporeal carbon dioxide removal.

• Authors: Pier Paolo Terragni, Lorenzo Del Sorbo, Luciana Mascia, Rosario Urbino, Erica L Martin, Alberto Birocco, Chiara Faggiano, Michael Quintel, Luciano Gattinoni, V Marco Ranieri
• Journal: Anesthesiology (Anesthesiology) Vol. 111 Issue 4 Pg. 826-35 (Oct 2009) ISSN: 1528-1175 [Electronic] United States
• PMID: 19741487 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Cytokines
• Carbon Dioxide

Topics

• Acidosis, Respiratory (therapy)
• Aged
• Air Pressure
• Carbon Dioxide (blood, isolation & purification)
• Cardiac Output (physiology)
• Cytokines (blood)
• Extracorporeal Membrane Oxygenation
• Female
• Humans
• Hydrogen-Ion Concentration
• Lung (diagnostic imaging, pathology)
• Lung Diseases (pathology, prevention & control)
• Male
• Middle Aged
• Pneumonia (pathology)
• Positive-Pressure Respiration
• Respiration, Artificial (adverse effects)
• Respiratory Distress Syndrome (therapy)
• Respiratory Function Tests
• Tidal Volume (physiology)
• Tomography, X-Ray Computed