Perfluorocarbon broncho-alveolar lavage and liquid ventilation versus saline broncho-alveolar lavage in adult guinea pig experimental model of meconium inhalation.
OBJECTIVE
This study compares perfluorocarbon broncho-alveolar lavage (PFC-BAL) with isotonic saline broncho-alveolar lavage (saline-BAL) in an experimental model of meconium aspiration in adult guinea pigs.


METHODS
Prospective controlled experimental study.


METHODS
Ten male guinea pigs were given 1 ml of human meconium, diluted to 10% in isotonic saline, via tracheostomy and then artificially ventilated. After stabilization, five animals (control group) underwent BAL with 10 ml/ kg isotonic saline solution. After bronchial suctioning, a further BAL with 2 ml/kg saline was performed. The other five animals (study group) underwent BAL with 100 ml/kg of PFC (RIMAR 101). Bronchosuction was effected at 5 min and then a BAL with PFC 2 ml/kg was performed. Both groups received conventional mechanical ventilation during the lavage procedures. Within 20 min all the saline-BAL treated animals died, whereas the PFC-BAL treated animals survived and were then treated with total liquid ventilation (TLV) by gravity.


RESULTS
After meconium inhalation in both groups, a large alveolar-arterial oxygen difference, hypercarbia, severe acidosis and tachycardia were noticed. In PFC treated animals, an improvement in blood gases was noted and acid-base balance remained stable compared to saline-BAL treated animals. No haemodynamic change was observed during or after PFC-BAL, while during saline-BAL there was evidence of bradycardia, hypotension and respiratory failure, which led to the death of the animals. The histological lung sections in the PFC-BAL group showed evidence of normal alveolar expansion with a minimal presence of meconium debris in the small bronchioles. In saline-BAL treated animals, the lung structure appeared severely compromised with the presence of meconium in bronchioles and alveoli, intra-alveolar oedema and haemorrhagic areas.


CONCLUSIONS
This study confirms the detrimental effects of meconium aspiration and the impairment of lung function following saline-BAL. By contrast, PFC-BAL and TLV by gravity seemed to prevent absorption of meconium, facilitate its removal, improve gas exchange and reduce lung barotrauma.
Marraro
G
G
Department of Anaesthesia & Intensive Care, Fatebenefratelli and Ophthalmiatric Hospital, Milano, Italy.
Bonati
M
M
Ferrari
A
A
Barzaghi
M M
MM
Pagani
C
C
Bortolotti
A
A
Galbiati
A
A
Luchetti
M
M
Croce
A
A
D000208:Acute Disease; D000704:Analysis of Variance; D000818:Animals; D018893:Bronchoalveolar Lavage / Q000379:methods* / Q000706:statistics & numerical data; D004195:Disease Models, Animal; D005069:Evaluation Studies as Topic; D005466:Fluorocarbons / Q000008:administration & dosage*; D006168:Guinea Pigs; D006801:Humans; D007231:Infant, Newborn; D008168:Lung / Q000473:pathology; D008297:Male; D008471:Meconium Aspiration Syndrome / Q000473:pathology / Q000628:therapy*; D011446:Prospective Studies; D011897:Random Allocation; D012121:Respiration, Artificial / Q000379:methods* / Q000706:statistics & numerical data; D012965:Sodium Chloride / Q000008:administration & dosage*
D005466:Fluorocarbons; D012965:Sodium Chloride