A randomized controlled trial of sodium bicarbonate in neonatal resuscitation—effect on immediate outcome
Introduction
Perinatal asphyxia is one of the leading causes of perinatal mortality, being responsible for 30–52% of perinatal deaths in developing countries [1]. In addition it can lead to long-term neurological handicap and is an antecedent factor in nearly 50% of neonatal deaths [2].
James et al. found that, in a continuously asphyxiated fetus, there is a progressive fall in pH from 7.32 to 7.00 at 5 min and to 6.8 at 10 min [3]. Severe acidosis impairs myocardial contractility and constricts the pulmonary blood vessels. In this situation, even when the neonate is ventilated adequately, satisfactory oxygenation may not be possible due to reduced pulmonary perfusion [4]. Drugs such as adrenaline (epinephrine) are less effective during acidosis [5]. Correction of acidosis by buffer agents such as sodium bicarbonate given during resuscitation may help by reversing these processes.
Resuscitation guidelines for the newborn state that use of sodium bicarbonate may be beneficial in prolonged arrest and generally should be used in documented metabolic acidosis [6], [7]. However, there are no controlled trials that have specifically examined the role of bicarbonate during neonatal resuscitation.
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Material and methods
Consecutively born asphyxiated neonates continuing to need positive pressure ventilation at 5 min of life were randomly assigned by a computer generated sequence to receive either sodium bicarbonate or 5% dextrose. Babies with major congenital malformations were excluded. The study group was given intravenous sodium bicarbonate solution 4 ml/kg (1.8 meq./kg) over 3–5 min. This solution was prepared by diluting 7.5% sodium bicarbonate (0.9 meq./ml) with distilled water in a 1:1 ratio. The placebo
Results
Out of the 60 babies enrolled, 5 babies were excluded because of major congenital malformations. Of the remaining 55, 27 were randomized to receive sodium bicarbonate (bicarb group) and 28 to receive 5% dextrose.
The mean gestation, birth weight, proportion of premature babies, mode of delivery, duration of labour, pregnancy induced hypertension (PIH)/eclampsia, incidences of meconium stained liquor and fetal bradycardia were similar in the two groups (Table 1). Apgar scores at 1min, cord pH,
Discussion
Patients in cardiac arrest have acidosis which compromises myocardial function [10], [11]. Hence, it makes physiologic sense that correction of acidosis should be beneficial during resuscitation. There are no neonatal animal or human trials that have specifically examined the role of bicarbonate in achieving return of spontaneous circulation or survival following cardiopulmonary resuscitation. The results of our study indicate that administration of sodium bicarbonate during resuscitation did
Conclusions
The results of this study support the current thinking that use of sodium bicarbonate during neonatal resuscitation does not help in improving survival and immediate neurological outcomes.
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