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Effects of exogenous surfactant on gas exchange and compliance in rabbits after meconium aspiration
Author(s) -
Robinson Tonya W.,
Roberts Andrew M.
Publication year - 2002
Publication title -
pediatric pulmonology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.866
H-Index - 106
eISSN - 1099-0496
pISSN - 8755-6863
DOI - 10.1002/ppul.10056
Subject(s) - meconium aspiration syndrome , meconium , medicine , anesthesia , bolus (digestion) , pulmonary surfactant , pulmonary compliance , tracheal tube , compliance (psychology) , respiratory system , surgery , pregnancy , intubation , fetus , chemistry , biochemistry , genetics , biology , social psychology , psychology
Success in using adjunctive surfactant therapy for meconium aspiration has been inconsistent. We tested the hypothesis that the ability of exogenous surfactant to improve gas exchange and pulmonary compliance after meconium aspiration is related to the method of surfactant administration. In anesthetized rabbits (2.4 ± 0.16 kg body weight), an endotracheal tube (ETT) was placed in the lower trachea, and the lungs were ventilated mechanically. After a control period, filtered meconium (3–5 mL/kg) was instilled through the ETT. Group 1 (n = 5) was not given surfactant. Thirty minutes after meconium instillation, group 2 (n = 5) was given a bolus of bovine surfactant (Beractant, 4 mL/kg) through the ETT, and group 3 (n = 5) was given an infusion of Beractant (4 mL/kg for 1 hr) through the side‐port of the ETT. Thirty minutes after meconium instillation, tracheal pressure increased by 8 ± 1 cm H 2 O (mean ± SEM), dynamic compliance decreased by 0.36 ± 0.07 mL/cm H 2 O/kg, arterial PO 2 (PaO 2 ) decreased by 49 ± 6.0 mmHg, arterial PCO 2 (PaCO 2 ) increased by 12 ± 2.4 mmHg, and arterial pH (pHa) decreased by 0.09 ± 0.02. After 3 hr of exposure to meconium, tracheal pressure was significantly ( P < 0.001) lower in group 3 compared to groups 1 or 2. PaO 2 remained below baseline in all groups. Group 3 had a significantly ( P = 0.001) higher dynamic compliance than groups 1 or 2. Likewise, static compliance was higher for group 3 compared to groups 1 or 2, with the greatest difference at low lung volume. Mean arterial blood pressure, pulse rate, PaCO 2 , and pHa were not significantly different between groups. These results suggest that continuous infusion of exogenous surfactant is more effective than bolus administration in improving pulmonary function after meconium aspiration. Pediatr Pulmonol. 2002; 33:117–123. © 2002 Wiley‐Liss, Inc.