Stressful events – a byproduct of life for babies in the NICU – may increase their heart rate and blood pressure, while decreasing their oxygen levels.([FOOTNOTE=Peng N-H, Bachman J, Jenkins R, et al. Relationships between environmental stressors and stress biobehavioral responses of preterm infants in NICU. J Perinat Neonatal Nurs. 2009;23(4):363-371.],[ANCHOR=],[LINK=]) Even sensory and environmental stimuli we take for granted, such as a simple touch and noise and bright lights, can affect physiologic responses such as heart rate, respiration, and oxygen saturation.1,([FOOTNOTE=Smith JR. Comforting touch in the very preterm hospitalized infant: an integrative review. Adv Neonatal Care. 2012;12(6):349-365.],[ANCHOR=],[LINK=])
The additive impact of multiple stressors over time may have profound long-term consequences on the lives of NICU babies.([FOOTNOTE=Newnham CA, Inder TE, Milgrom J. Measuring preterm cumulative stressors within the NICU: the Neonatal Infant Stressor Scale. Early Hum Dev. 2009;85(9):549-555.],[ANCHOR=],[LINK=]) In the rapidly developing perinatal brain, repeated neonatal stress may have long-term effects on the central nervous system,3 including effects on neural structure, function, and development.3,([FOOTNOTE=Smith BA, Gutovich J, Smyser MD, et al. Neonatal intensive care unit stress is associated with brain development in preterm infants. Ann Neurol. 2011;70(4):541-549.],[ANCHOR=],[LINK=])
Intubated infants can’t audibly cry([FOOTNOTE=Hand IL, Noble L, Geiss D, Wozniak L, Hall C. COVERS Neonatal pain scale: development and validation. Int J Pediatr. 2010;2010: 496719.],[ANCHOR=],[LINK=]) — air can’t flow across their vocal cords.([FOOTNOTE=Grossbach I, Stranberg S, Chlan L. Promoting effective communication for patients receiving mechanical ventilation. Crit Care Nurse. 2011;31:46-60.],[ANCHOR=],[LINK=]) But intubated infants can give voice to their distress through behavioral and physiological signs.([FOOTNOTE=Peng N-H, Bachman J, Jenkins R, et al. Relationships between environmental stressors and stress biobehavioral responses of preterm infants in NICU. J Perinat Neonatal Nurs. 2009;23(4):363-371.],[ANCHOR=],[LINK=])
By recognizing stressors, understanding their impact, and monitoring premature babies closely, clinicians can develop plans to help improve care for their fragile neonatal patients and may improve neurologic and behavioral outcomes.([FOOTNOTE=Smith JR. Comforting touch in the very preterm hospitalized infant: an integrative review. Adv Neonatal Care. 2012;12(6):349-365.],[ANCHOR=],[LINK=]),([FOOTNOTE=Anand KJ, International Evidence-Based Group for Neonatal Pain. Consensus statement for the prevention and management of pain in the newborn. Arch Pediatr Adolesc Med. 2001;155(2):173-180.],[ANCHOR=],[LINK=])
To minimize NICU stress, we first need tools that provide consistent measurements removing variability of individual clinician assessments.([FOOTNOTE=Newnham CA, Inder TE, Milgrom J. Measuring preterm cumulative stressors within the NICU: the Neonatal Infant Stressor Scale. Early Hum Dev. 2009;85(9):549-555.],[ANCHOR=],[LINK=]) The Neonatal Infant Stressor Scale (NISS) is a standardized instrument that allows clinicians to record every stressor experienced by a NICU infant and calculate a cumulative stress score.7
Based on a survey of clinician impressions of infant responses, the NISS assigns weighted values to specific NICU events (e.g. heel lance) and chronic conditions such as systemic infection and interventions such as administration of intranasal oxygen.7 The NISS is suggested to be used in conjunction with standard observations of pain, "to help track, measure, and manage presumed accumulated stress in preterm neonates."7 This information can help clinicians in the NICU to make the most informed decisions when evaluating interventions to reduce stress in fragile preterm infants.
*All signs of stress may not be described here. These signs may or may not indicate a stressful event.