The Relation between Role of Serum Cortisol Level and Response to Various Respiratory Support Strategies among Preterm Infants

Introduction: Preterm infants are liable to various health problems including respiratory distress syndrome (RDS). There is variation in response to respiratory support. In preterm infants, cortisol hormone is secreted by the adrenocortical gland in response to stress. Objectives: To compare the serum cortisol levels in blood among preterm infants who needed different respiratory support strategies e.g. headbox, continuous positive airway pressure (CPAP), intubation surfactant extubation (INSURE) and mechanical ventilation (MV) and to correlate the cortisol levels to the severity of respiratory distress syndrome (RDS). Material and Methods: Observational prospective study that assessed the serum cortisol levels in preterm infants with RDS after initial respiratory support aged 28 - 34 gestational weeks that were admitted to the neonatal intensive care unit of Al Zahraa hospital of Al-Azhar University and Al-Estekama hospital between February 2019 and November 2019. Infants were classified into three groups, Group 1: 29 infants with severe RDS who needed a mechanical ventilator. Ten of them needed surfactant therapy. Group 2: 33 infants with moderate RDS who needed CPAP. Three of them needed surfactant therapy. Group 3: 28 infants with symptoms of mild RDS who needed headbox. None of them needed surfactant therapy. Blood samples were collected on the first day of life and were processed using the colorimetric ELISA method. Demographic and medical information was collected. Results: A total of 90 preterm infants were included. The serum cortisol reference was 4.3 - 22.4 mg/dl. Group 1 showed significantly higher serum cortisol levels compared to group 2 and group 3 (39.22 ± 9.91 mg/dl vs 28.96 ± 6.48 mg/dl vs 25.88 ± 5.42 mg/dl) respectively, (P-value = 0.001). Infants in group 2 who needed surfactant therapy had higher serum cortisol levels than those who did not need surfactant therapy (32.30 ± 5.92 mg/dl vs 28.33 ± 6.27 mg/dl). The serum cortisol levels were observed having a negative correlation with gestational age and birth weight. No significant differences were observed in terms of gender or type of delivery. Conclusion: Cortisol levels had a positive correlation with the severity of RDS who needed various respiratory support strategies.

Comparison of Respiratory Outcome between Sustained Lung Inflation and Intermittent Positive Ventilation in Preterm Infants Requiring Resuscitation at Birth

Background: Sustained lung inflation (SLI) would permit lung recruitment immediately after birth, improving lung mechanics and reducing the need for intubation and subsequent respiratory support in the neonatal intensive care unit among preterm infants. Aim of the Study: To assess the efficacy of initial sustained lung inflation compared to standard intermittent positive pressure ventilation (IPPV) in preterm infants who need resuscitation in delivery room. Methods: This was prospective randomized observational study that was conducted in the delivery room and NICU of A in shames University hospital from February 2019 to September 2019. The study included 115 preterm infants between 26 - 32 weeks of gestation who needed resuscitation at delivery room. The infants were randomly allocated into 2 groups;SLI group: included the preterm infants who received the SLI at initial inflation pressure of 25 cm H2O for 15 seconds using the Neopuff/T piece. IPPV group: preterm infants who received standard resuscitation;IPPV using the self-inflating bag. The heart rate (HR), oxygen saturation (SpO2), oxygen requirement, and intubation rate as well as need of surfactant in the delivery room were assessed. All cases were evaluated after admission to the NICU for the need of mechanical ventilation in the first 72 hours of life, death in delivery room or NICU and for bronchopulmonary dysplasia or death at 36 weeks post menstrual age (PMA). Results: The percentage of preterm infants who needed resuscitation was 25.5% from the total deliveries during the study period. 56.5% of them received SLI and 43.4% received conventional IPPV. There were no significant differences between the studied groups regarding gestational age, birth weight. Apgar score, heart rate, oxygen saturation was not significantly increased in the SLI group at fifth minutes of age. The percentage of infants who needed further resuscitation was 20% in SLI group and 12% in the IPPV group. There were no significant differences in need for surfactant, CPAP or ventilator among the studied groups. There were no significant differences in relation to complications as BPD, air leak or retinopathy and death between the two groups. Conclusion: This study showed that there was no advantage from use of SLI in delivery room using T-piece upon the conventional IPPV using self-inflating bag.