tailieunhanh - Neonatal Formulary - part 6

Manitol được công nhận là có một vai trò quan trọng trong việc ngăn ngừa và giảm thiểu thiệt hại gây ra do chấn thương não cấp tính. Tiện ích của nó trong việc quản lý phù não thiếu ôxy sau ít thiết lập rõ ràng. | MANNITOL Use Mannitol is now recognised as having a valuable role in preventing and minimising the damage caused by acute cerebral trauma. Its utility in managing post-anoxic cerebral oedema is less clearly established. Mannitol is sometimes used in adults to induce the forced diuresis of renally excreted poisons. Pharmacology Mannitol is a relatively inert hexahydric alcohol related to mannose and isomeric with the sugar sorbitol. It is rapidly excreted in the urine very little is metabolised. Nothing is known about its use during pregnancy or lactation. A recent large trial has shown that the early infusion of a large dose to all patients prior to surgical decompression whatever their initial clinical condition significantly decreased the amount of residual disability seen 6 months later and it now seems clear that it works more by decreasing the viscosity of the blood than by setting up an osmotic gradient to counter cerebral oedema. Mannitol works by diluting the blood and increasing the deformability of the red cells increasing cerebral blood flow initiating autoregulatory vasoconstriction of cerebral arterioles and decreasing intracerebral blood volume and intracranial pressure. Prompt bolus administration is therefore the strategy of choice in all patients with an acute traumatic subdural haematoma. Urinary loses should also be replaced - it is inappropriate to let dehydration and haemoconcentration occur. A similar strategy was equally effective in the preoperative management of adult patients undergoing surgical evacuation of traumatic temporal lobe contusion. Hypoxic ischaemic encephalopathy HIE While mannitol can undoubtedly reduce intracranial pressure it is increasingly clear that the rise in pressure sometimes but not always seen as a result of cerebral oedema is a sign that only develops after severe damage has already occurred. One small trial of early intervention with phenobarbital . before seizures occurred seemed to show evidence of benefit .