Bonnie Stevens1, Sharyn Gibbins1, Patrick McGrath1, Celeste Johnston1, Marsha Campbell-Yeo
Background and aims: Limited knowledge exists on Extremely Low Gestational Age (ELGA) infant responses to painful versus non-painful procedures and how contextual factors impact these responses. The aim was to determine the influence of sex, gestational age (GA), birth weight (BW), and severity of illness (SOI) on responses of hospitalized ELGA infants to painful versus non-painful procedures.
Methods: Using a prospective, observational repeated measures design, infants 23-28 weeks GA at birth from 2 level III Canadian Neonatal Intensive Care Units within 10 days of life were recruited. Infants were observed weekly for 3 consecutive weeks during a randomly ordered painful (heel lance) and non-painful (diaper-change) procedure. Facial actions [brow bulge (BB), eye squeeze (ES), and nasal labial furrow (NLF)], body actions [Hands to face (HF), finger splay (FS), and fisting (F)], and physiologic [heart rate (HR), oxygen saturation (O2 sat) indicators, were coded from continuous video recordings and physiologic monitoring by blinded coders. Data were analyzed using linear mixed models.
Results: 120 (66 females and 54 males) ELGA infants (average: 25.6 weeks GA; 839.7 grams; and SNAPPE score of 35.6) participated. We examined the influence of Procedure and Infant factors on infant pain responses. There was significantly greater response during painful versus non-painful procedures: (a) compared to males, females experienced larger increases in HR (p = 0.012); (b) as GA increased, NLF (p = 0.004) increased, while O2 sat (p = 0.006) and HR (p = 0.046) decreased; and (c) as SOI increased, ES increased (p = 0.007), and O2 sats decreased (p = 0.016).
Conclusion: Contextual factors exert important influences on infants’ pain responses. Further studies are needed to better understand these relationships.
Acknowledgements: This research is supported through a Canadian Institutes of Health Research Grant (MOP-7884).