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Published on: July 10, 2018
Comparison of the effects of low-dose vs. high-dose aminophylline on lung function in experimental meconium
1Department of Physiology, Jessenius Faculty of Medicine, Comenius University, Martin, Slovakia. mokra@jfmed.uniba.sk
Abstract:
Due to missing information on appropriate dosing of aminophylline in meconium aspiration syndrome (MAS), this study compared effects of high-dose and low-dose aminophylline on lung function of animals with MAS. Meconium-instilled rabbits were treated by low-dose (LD, 1.0 mg/kg), or high-dose (HD, 2.0 mg/kg) aminophylline at 0.5 and 2.5 h after meconium instillation, or were left untreated. Within 5 h of oxygen ventilation, HD-aminophylline improved gas exchange, reduced pulmonary shunts and ventilatory pressures, and decreased edema formation and lung neutrophils. LD-aminophylline enhanced lung function to a lower extent than HD-aminophylline, and failed to reduce lung edema and the number of lung neutrophils. Both treatments decreased lung peroxidation, with a stronger effect of HD-aminophylline on lipid oxidation and of LD-aminophylline on protein oxidation. Tracheal reactivity to histamine decreased after HD-aminophylline, while lung tissue reactivity was more reduced after LD-aminophylline. Although LD-aminophylline showed some anti-inflammatory potential, HD-aminophylline improved most of the parameters more effectively.
Insights
High-dose aminophylline significantly improved lung function in meconium aspiration syndrome (MAS) models, outperforming low-dose treatments. This suggests higher doses are more effective for treating MAS-related respiratory distress.
Area of Science:
- Neonatal Medicine
- Pulmonary Pharmacology
- Respiratory Physiology
Background:
- Meconium aspiration syndrome (MAS) poses significant risks to newborns, often requiring respiratory support.
- Optimal therapeutic strategies, particularly aminophylline dosing, remain under-investigated in MAS.
- Existing research lacks clear guidelines on aminophylline's efficacy in MAS treatment.
Purpose of the Study:
- To compare the effects of high-dose (HD) versus low-dose (LD) aminophylline on lung function in a rabbit model of MAS.
- To evaluate aminophylline's impact on gas exchange, pulmonary hemodynamics, inflammation, and oxidative stress in MAS.
- To determine the optimal dosage of aminophylline for managing MAS complications.
Main Methods:
- MAS was induced in rabbits via meconium instillation.
- Animals received either HD (2.0 mg/kg) or LD (1.0 mg/kg) aminophylline at 0.5 and 2.5 hours post-instillation, or served as untreated controls.
- Lung function parameters, including gas exchange, ventilatory pressures, edema, neutrophils, peroxidation, and tracheal reactivity, were assessed within 5 hours of ventilation.
Main Results:
- HD-aminophylline significantly improved gas exchange, reduced pulmonary shunts, ventilatory pressures, edema, and lung neutrophils compared to controls.
- LD-aminophylline showed some lung function improvement but was less effective than HD-aminophylline, failing to reduce edema or neutrophils.
- Both doses reduced lung peroxidation, with HD-aminophylline showing a stronger effect on lipid oxidation and LD-aminophylline on protein oxidation. Tracheal reactivity decreased with both treatments, more so in lung tissue with LD-aminophylline.
Conclusions:
- High-dose aminophylline demonstrates superior efficacy in improving lung function and mitigating key pathological features of MAS compared to low-dose administration.
- While LD-aminophylline exhibits some anti-inflammatory effects, HD-aminophylline provides more comprehensive benefits in managing MAS.
- Further clinical investigation into HD-aminophylline for MAS treatment is warranted based on these findings.
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