The effects of sodium bicarbonate on brain blood flow, brain water content, and blood-brain barrier in the neonatal dog

Abstract

To explore the relationship between cerebral hemorrhage in the newborn and administration of sodium bicarbonate, we gave a standard dose of sodium bicarbonate (5 mEq/kg) to neonatal dogs and then assessed changes in cerebral blood flow, brain water content, and the blood-brain barrier. This dose of sodium bicarbonate produced no increase in blood pressure or cerebral blood flow and no alteration in blood-brain barrier. However, infusion of sodium bicarbonate did cause hyperosmolality and hypernatremia and a significant decrease in brain water content. Cerebral hemorrhage in the neonate associated with infusions of sodium bicarbonate may be related to shifts in brain water rather than to changes in blood pressure or cerebral blood flow.

Effects of Rapid versus Slow Infusion of Sodium Bicarbonate on Cerebral Hemodynamics and Oxygenation in Preterm Infants

“…The length of hyperosmolarity after NaHCO 3 infusion is unknown. Siegel et al [11] described a brief increase in blood osmolarity directly after NaHCO 3 infusion while others reported a persisting hyperosmolarity 30 min after NaHCO 3 administration [10] . The increase in CBV in our study is most likely related to cerebral vasodilatation due to hyperosmolarity.…”

“…In previous studies, single measurements of CBF after NaHCO 3 infusion showed confl icting data. In healthy adults, NaHCO 3 administration resulted in an increased CBF [7] , whereas NaHCO 3 infusion did not lead to changes in CBF in animal studies [9,10] . Lou et al [34] reported a decrease in CBF after NaHCO 3 infusion in distressed preterm infants with severe metabolic acidosis.…”

“…NaHCO 3 administration provokes hypercapnia [7][8][9] , hyperosmolarity [7,10,11] and changes in hemodynamics [12][13][14] which can lead to changes in cerebral blood fl ow (CBF) when auto-regulation is impaired. Fluctuating CBF is a known risk factor for IVH in preterm infants [15] .…”

Sodium Bicarbonate Lowers Intracranial Pressure After Traumatic Brain Injury

“…A study on neonatal dogs found that infusion of hypertonic sodium bicarbonate caused a significant reduction in brain water content [16]. Several human studies have demonstrated an increase in cerebral blood flow after sodium bicarbonate infusion [17,18].…”

Effect of bicarbonate on retinal vasculature and acidosis-induced retinopathy in the neonatal rat

“…Another possible explanation for the high mortality rate observed with bicarbonate administration may be the additional effect of osmotic load due to the dissociation of sodium bicarbonate [16]. The increase in sodium ion concentration may worsen dehydration [17] of rats that are already somewhat dehydrated due to relative milk restriction induced by the expanded litter size study design. It is also probable that systemic bicarbonate may produce additional systemic effects leading to the higher mortality rates observed.…”