Details

Autor(en) / Beteiligte

• Xu, Yongmei
• Kobayashi, Tsutomu
• Cui, Xiaoguang
• Ohta, Keisuke
• Kabata, Chiharu
• Tashiro, Katsumi

Titel

Lung volumes and alveolar expansion pattern in immature rabbits treated with serum-diluted surfactant

Ist Teil von

• Journal of applied physiology (1985), 2004-10, Vol.97 (4), p.1408-1413

Ort / Verlag

Bethesda, MD: Am Physiological Soc

Erscheinungsjahr

2004

Link zum Volltext

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• Department of Anesthesiology and Intensive Care Medicine, Graduate School of Medical Science, Kanazawa University, Kanazawa 920-8641, Japan Submitted 29 September 2003 ; accepted in final form 8 June 2004 In acute respiratory distress syndrome, mechanical ventilation often induces alveolar overdistension aggravating the primary insult. To examine the mechanism of overdistension, surfactant-deficient immature rabbits were anesthetized with pentobarbital sodium, and their lungs were treated with serum-diluted modified natural surfactant (porcine lung extract; 2 mg/ml, 10 ml/kg). By mechanical ventilation with a peak inspiration pressure of 22.5 cmH 2 O, the animals had a tidal volume of 14.7 ml/kg (mean), when 2.5 cmH 2 O positive end-expiratory pressure was added. This volume was similar to that in animals treated with nondiluted modified natural surfactant (24 mg/ml in Ringer solution, 10 ml/kg). However, the lungs fixed at 10 cmH 2 O on the deflation limbs of the pressure-volume curve had the largest alveolar/alveolar duct profiles ( 48,000 µm 2 ), accounting for 38% of the terminal air spaces, and the smallest (<6,000 µm 2 ), accounting for 31%. These values were higher than those in animals treated with nondiluted modified natural surfactant ( P < 0.05). We conclude that administration of serum-diluted surfactant to immature neonatal lungs leads to patchy overdistension of terminal air spaces, similar to the expansion pattern that may be seen after dilution of endogenous surfactant with proteinaceous edema fluid in acute respiratory distress syndrome. acute respiratory distress syndrome; alveolar overdistension; dynamic surface tension; positive end-expiratory pressure Address for reprint requests and other correspondence: K. Tashiro, Dept. of Anesthesiology and Intensive Care Medicine, Graduate School of Medical Science, Kanazawa Univ., Kanazawa 920-8641, Japan (E-mail: tashirk{at}anesth.m.kanazawa-u.ac.jp ).