Use of THAM and sodium bicarbonate in correcting acidosis in asphyxiated newborns.

Fetal and Neonatal Response to Base Loading

“…From the clinical point of view, the administration of alkaline solutions in the management of fetal and neonatal respiratory distress has been based on the following assumptions: (a) that, along with hypoxia, acidosis is invariably observed in this condition ; (b) that the acidosis produces pulmonary vasoconstriction which further aggra vates the hypoxia; and (c) that base infusion corrects the acidosis, improving thereby the pulmonary circulation and neonatal oxyge nation [4,5,6,7,23,24,25]. The present studies show that in neither fetus or the neonate did the p 0 2 of the blood change appreciably during base infusion.…”

“…But the response of the fetus before and immediately after cord clamping has not been in vestigated. The need for such studies has recently become pressing in view of the current interest in the administration of bicarbonate solutions to mother or newborn as a part of the management of fetal and neonatal distress (4,5,6,7].The present studies deal with the changes in blood and urine com position produced by bicarbonate infusion in the nearterm fetal lamb before and after lung expansion and umbilical cord clamping. …”

History of Neonatal Resuscitation – Part 2: Oxygen and Other Drugs

“…Administration of alkali (Na-bicabonate and Tris) and glucose reduced the incidence and the extent of brain damage.' Clinical non-randomized studies seemed to confirm the benefit of buffers, and when several prominent obstetricians recommended bicarbonate and THAM for birth asphyxia [37,38] , a widespread use of alkali invaded textbooks and delivery rooms [39] . Even though the randomized trial by Corbet et al [40] showed that giving bicarbonate to asphyxiated infants neither accelerated correction of acidemia nor reduced mortality, it took many more years to stop 'blind buffering' in delivery rooms.…”

Effects of a Continuous Infusion of Tris(hydroxymethyl)aminomethane on Acidosis, Oxygen Affinity, and Serum Osmolality

“…HCOH^ + H+ t t H2C 0 3 & H20 + C 0 2 (1) Unless there is adequate removal of CO2, the carbon dioxide tension may rise after bicar bonate administration. This has been well documented in animals [1,2] and in human neonates receiving sodium bicarbonate [3,4], In situations in which the pulmonary ex change of CO2 is severely limited, the rise in the paCCF could limit the effectiveness of sodium bicarbonate in raising the pH.…”

“…Its use has been investigated in adult experimental animals and in human adults, children, and neonates. THAM has been shown to produce and in crease in pH and a decrease in paCCF [1-3, 8, 9] under most conditions, with a frequent finding of either hypoventilation or apnea [1,4,10,11], This has been attributed to the decrease in paCCF, causing depression of the respiratory center, and has prompted the rec ommendation of the use of mechanical venti lation along with THAM administration [12]. Hyperosmolality was reported in nephrectomized animals [13] and in human infants given THAM by rapid bolus infusion [3], Oth er side effects reported are hyperkalemia [6] and hypoglycemia [14], THAM was also shown to increase the oxygen affinity of adult whole blood in vitro [15], Because of these concerns, as well as the paucity of data on THAM pharmacokinetics, THAM has been used less frequently in recent years.…”