Abstract | BACKGROUND: Because cardiovascular functions and their control mechanisms may be influenced by meconium aspiration and by treatment, cardiovascular parameters including heart rate variability (HRV) were evaluated after meconium instillation and treatment with dexamethasone. METHODS: Adult rabbits were anesthetized, paralyzed, and artificially ventilated. Meconium suspension (25 mg/mL, 4 mL/kg) was instilled intratracheally to induce respiratory failure. Thirty minutes later, animals received i.v. dexamethasone (0.5 mg/kg; dexa group, n = 6) or were left without treatment (control group, n = 5). All animals were ventilated for an additional 5 h. Mean heart rate (MHR), mean blood pressure (MBP), central venous pressure (CVP), and time and spectral analyses of HRV were registered and evaluated. Blood gases were measured and right-to-left pulmonary shunts (RLS) calculated. RESULTS: Immediately after meconium instillation, MBP, CVP, and RLS increased and MHR decreased (P < 0.05). MHR and MBP were restored within several minutes, while CVP and RLS remained high until the end of experiment. Thirty minutes after meconium instillation, slightly but non-significantly higher spectral powers in all frequency bands of HRV were found (P > 0.05). Dexamethasone treatment enhanced oxygenation (P < 0.05) and slightly reduced PaCO(2) (P > 0.05), increased parasympathetic activity expressed by mean squared successive difference and decreased spectral power in the very low frequency band (P < 0.05) compared to controls, but had no significant effect on MHR, MBP, CVP, and RLS. CONCLUSIONS:
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Authors | Daniela Mokra, Ingrid Tonhajzerova, Maria Petraskova, Andrea Calkovska |
Journal | Pediatrics international : official journal of the Japan Pediatric Society
(Pediatr Int)
Vol. 51
Issue 1
Pg. 132-7
(Feb 2009)
ISSN: 1442-200X [Electronic] Australia |
PMID | 19371293
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
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Topics |
- Animals
- Blood Gas Analysis
- Blood Pressure
(drug effects)
- Cardiovascular System
(drug effects)
- Central Venous Pressure
(drug effects)
- Dexamethasone
(pharmacology, therapeutic use)
- Heart Rate
(drug effects)
- Humans
- Infant, Newborn
- Meconium Aspiration Syndrome
(drug therapy, physiopathology)
- Pulmonary Circulation
(drug effects)
- Rabbits
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