Enhanced cerebral blood flow autoregulation in the newborn piglet by d-tubocurarine and pancuronium but not by vecuronium.
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)
Department of Pediatrics, University of Iowa, Iowa City.
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Chemtob
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Barna
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Beharry
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Aranda
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Varma
D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000187:drug effects / Q000502:physiology*; D006706:Homeostasis / Q000187:drug effects*; D010197:Pancuronium / Q000494:pharmacology*; D013268:Stimulation, Chemical; D014403:Tubocurarine / Q000494:pharmacology*; D014673:Vecuronium Bromide / Q000494:pharmacology*
D014673:Vecuronium Bromide; D010197:Pancuronium; D014403:Tubocurarine