ABSTRACT
Recent progress in understanding the pathophysiology of hypoxic-ischemic encephalopathies and intraventricular hemorrhages have enabled us to propose new therapeutic modalities in preventing the development and severity of these disorders in the newborn. Because neuronal damage may be reversible under certain conditions, appropriate evaluation of these drugs (single or in combination) is very important in the continuous attempt to ameliorate the neurodevelopmental outcome of these infants. An interventionist attitude should prove to be a better alternative than a supportive one.
Subject(s)
Asphyxia Neonatorum/drug therapy , Brain Ischemia/drug therapy , Cerebral Hemorrhage/prevention & control , Fetal Hypoxia/drug therapy , Asphyxia Neonatorum/etiology , Barbiturates/therapeutic use , Brain Ischemia/etiology , Cerebral Hemorrhage/etiology , Female , Fetal Hypoxia/etiology , Humans , Indomethacin/therapeutic use , Infant , Infant, Newborn , Pancuronium/therapeutic use , PregnancyABSTRACT
Neuromuscular blockers may affect cerebral blood flow (CBF) regulation in the newborn. We studied the effects of d-tubocurarine (0.1 mg.kg-1, n = 8), pancuronium (0.1 and 0.4 mg.kg-1, n = 6 and 7), and vecuronium (0.1 and 0.4 mg.kg-1, n = 6 and 7) on CBF measured over the same range of mean systemic blood pressure ([BP] 15-122 mmHg) in each group of newborn pigs; controls received normal saline (n = 7). The levels of BP during hypotension and hypertension were scaled at intervals of 5 +/- 1.6 mmHg and adjusted by inflating balloon-tipped catheters placed in the aorta. After saline, the low dose of pancuronium (0.1 mg.kg-1), and the two doses of vecuronium, CBF was constant over the BP range of 50-90 mmHg (r = -0.07-0.35, P greater than 0.20) but varied directly with BP beyond this range (tau = 0.38 - 0.60, P less than 0.05). In contrast, in pigs treated with d-tubocurarine and high-dose pancuronium, CBF remained constant from 35 to 122 mmHg of BP (r = 0.14 - 0.37, P greater than 0.10) and changed minimally (4-12%) with BP greater than 105 mmHg compared to the other groups (41-59%, P less than 0.01). When BP was reduced below 30 mmHg, CBF also decreased less (20-38%) in animals treated with d-tubocurarine and high dose-pancuronium than after the other treatments (58-67%, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)