Effect of mechanical ventilation modes on salivary cortisol levels in preterm infants

Purpose: The aim of this study was to examine the relationship between mechanical ventilation modes and stress levels by measuring salivary cortisol levels in preterm infants.Materials and Methods: The study group comprised 65 preterm infants on respiratory support and 43 control preterm infants. The Neonatal Infant Pain Scale (NIPS) was used to evaluate pain. To determine the stress level, salivary cortisol levels were studied in saliva samples taken in the morning and evening on the 4th postnatal day.Results: In the study group, morning and evening cortisol levels of the infants were measured 8.33 +/- 5.7 ng/ml and 8.05 +/- 5.6 ng/ml, respectively. In the control group, morning and evening cortisol values of the infants were measured 1.50 +/- 0.7 ng/ml and 1.48 +/- 0.7 ng/ml, respectively. The morning and evening salivary cortisol levels of the infants in the study group were significantly higher than those of the infants in the control group. In the invasive mechanical ventilation group infants, morning and evening cortisol levels of the infants were measured 12.46 +/- 5,3 ng/ml and 12.0 +/- 5,2 ng/ml, respectively. In the non-invasive mechanical ventilation group, morning and evening cortisol values were measured 4.57 +/- 2.7 ng/ml and 4.41 +/- 2.7 ng/ml, respectively. Both morning and evening salivary cortisol levels of infants on invasive mechanical ventilation were higher than those of infants on noninvasive mechanical ventilation.Conclusion: Increased salivary cortisol levels in invasive modes indicate that intubation causes pain and stress in newborns.