Table 3.

Associations between prior pain exposure, prior morphine exposure and illness severity with facial and autonomic responses to heel lance and cortisol response to a series of nursing procedures

	Illness severity (snap II day I)	Pain exposure (number of skin breaking procedures) birth to 32 weeks	Morphine exposure (daily average mg/kg×days) birth to 32 weeks	Mechanical ventilation (days)
Infants born ≤ 28 weeks GAa
Facial (lance) n = 29	—0.26	—0.44*	—0.42*	—0.19
HR (baseline to lance) n = 28	—0.24	—0.09	—0.15	0.05
Low frequency (baseline to lance) n = 28	—0.02	—0.28	0.05	—0.31
High frequency (baseline to lance) n = 28	—0.25	—0.19	—0.34	—0.27
Cortisol (clustered care) n = 23	—0.17	—0.50*	—0.26	—0.37
Infants born 29—32 weeks GAb
Facial (lance) n = 43	0.16	0.05	0.19	—0.09
HR (baseline to lance) n = 45	—0.06	0.09	0.05	0.03
Low frequency (baseline to lance) n = 45	—0.36*	—0.10	—0.11	0.07
High frequency (baseline to lance) n = 45	—0.13	—0.11	—0.15	0.15
Cortisol (clustered care) n = 45	0.19	0.10	—0.04	0.12

^*P < 0.05

^an = 30 ELGA infants had one or more outcomes (facial, cardiac, cortisol).

^bn = 57 VLGA infants had one or more outcomes (facial, cardiac, cortisol).