Objectives: A proportion of preterm, very low birthweight (VLBW, , 1500 g) infants may show inadequate adrenal response to stress in the immediate postnatal period. The human corticotrophin releasing hormone (hCRH) stimulation test was used to: (a) determine the relation between pituitaryadrenal response and systemic blood pressure in these infants; (b) characterise the endocrinological features of transient adrenocortical insufficiency of prematurity (TAP). Study design: A total of 226 hCRH tests were performed on 137 VLBW infants on day 7 and 14 of life in a tertiary neonatal centre. Results: Basal, peak, and incremental rise in serum cortisol (DCort 0-30 ) on day 7 were associated significantly with the lowest systolic, mean, and diastolic blood pressures recorded during the first two weeks of life (r . 0.25, p , 0.005). These cortisol concentrations also correlated significantly but negatively with the maximum and total cumulative dose of dopamine (r . 20.22, p , 0.02), dobutamine (r . 20.18, p , 0.04), and adrenaline (r . 20.26, p , 0.004), total volume of crystalloid (r . 20.22, p , 0.02), and duration of inotrope treatment (r . 20.25, p , 0.006). Multivariate regression analysis of significant factors showed that the lowest systolic, mean, and diastolic blood pressures remained independently associated with serum cortisol (basal, peak, and DCort 0-30 ) on day 7. Hypotensive infants requiring inotropes (group 2) were significantly less mature and more sick than infants with normal blood pressure (group 1). The areas under the ACTH response curves were significantly greater in group 2 than in group 1, on both day 7 (p = 0.004) and day 14 (p = 0.004). In contrast, the area under the cortisol response curve was significantly greater in group 1 than in group 2 on day 7 (p = 0.001), but there was no significant difference between the two groups on day 14. In addition, serum cortisol at the 50th centile in hypotensive infants had high specificity and positive predictive value (0.80-0.93 and 0.81-0.89 respectively) for predicting early neonatal hypotension. Conclusions: This study characterises the fundamental endocrinological features of TAP: normal or exaggerated pituitary response; adrenocortical insufficiency; good recovery of adrenal function by day 14 of postnatal life. The results also provide the centiles of serum cortisol for hypotensive patients and infants with normal blood pressure, and show a significant relation between serum cortisol and blood pressure in VLBW infants.
This prospective study aims to investigate the factors that influence the human CRH (hCRH) test and to provide reference ranges for plasma corticotropin (ACTH) and serum cortisol concentrations of the stimulation test in preterm, very low birth weight (VLBW) infants. Two hundred twenty-six hCRH tests were performed on 137 VLBW infants at d 7 and 14 of life. Plasma ACTH did not differ significantly between infants whose mothers did not receive antenatal corticosteroids (group 1) and those whose mothers received one or two doses (group 2) or more than two doses (group 3) of the drug. However, plasma ACTH levels at d 7 were found to be significantly higher in infants with severe lung disease who required intermittent positive-pressure ventilation (IPPV) or high-frequency oscillation ventilation (HFOV), compared with those who had milder pulmonary disease and did not require mechanical ventilation or needed only continuous positive airway pressure (CPAP) support (P < 0.011). A significantly higher rate of increase in plasma ACTH concentration at d 7 was also observed in infants whose mothers suffered from antepartum hemorrhage (P < 0.016). In contrast, infants in group 2 had significantly lower serum cortisol, compared with group 1 infants (P < 0.05), whereas group 3 infants did not have serum cortisol levels significantly different from those of patients in group 1 or 2. Significant positive correlation between serum cortisol at d 7 and the time interval between the last dose of antenatal dexamethasone and delivery was also observed in group 3 infants (r > 0.33, P < 0.045). In addition, infants who required IPPV or HFOV had significantly lower serum cortisol at d 7 (P < 0.0001), but this pattern of cortisol response was reversed on d 14, with infants requiring IPPV or HFOV having significantly higher serum cortisol (P < 0.036). The reference ranges for plasma ACTH and serum cortisol concentrations of the hCRH test at d 7 and 14 were also provided for group 1 and group 2 infants. This study demonstrates that even one or two doses of antenatal corticosteroids cause adrenal suppression in VLBW infants. Maternal antepartum hemorrhage also influences the pituitary response of preterm newborns in the first week of life. The change in the pattern of cortisol response in sick ventilated (IPPV or HFOV) infants during the first 2 wk of life suggests that a proportion of preterm infants may have inadequate adrenal response to stress in early postnatal life, but it is likely that rapid adaptation of the hypothalamic-pituitary-adrenal axis results in enhanced and more appropriate cortisol response by d 14. The percentile distribution of plasma ACTH and serum cortisol responses provides useful statistical reference data for interpretation of the hCRH test in VLBW infants and may also assist in facilitating the use of corticosteroids replacement therapy in cases with clinical manifestations suggestive of adrenal insufficiency.
Postpartum haemorrhage accounts for nearly 28% of maternal mortality in developing countries. Syntometrine is an effective and commonly used oxytocic in preventing postpartum haemorrhage, but it requires a controlled storage environment and i.m. administration. Misoprostol is an orally active uterotonic agent. A total of 2058 patients having a singleton pregnancy, low risk for postpartum haemorrhage and vaginal delivery were randomized to receive either 1 ml syntometrine or 600 microgram misoprostol for the management of the third stage of labour. There were no significant differences between the two groups in the mean blood loss, the incidence of postpartum haemorrhage and the fall in haemoglobin concentration. The need for additional oxytocic injection was significantly higher in the misoprostol group [relative risk (RR) 1.62, 95% confidence interval (CI) 1.34-1.96], but that of manual removal of placenta was reduced (RR 0.29, 95% CI 0.09-0.87). Shivering and transient pyrexia were more common in the misoprostol group. Oral misoprostol might be used in the management of the third stage, especially in situations where the use of syntometrine is contraindicated and facilities for storage and parenteral administration of oxytocics are limited.
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