Variability in pain response to a non-pharmacological intervention across repeated routine pain exposure in preterm infants: a feasibility study.
OBJECTIVE
To explore the variability in pain response in preterm infants across time who received sucrose during routine heel stick.


METHODS
Single group, exploratory repeated measures design.


METHODS
Two tertiary level neonatal intensive care units (NICU) in Switzerland.


METHODS
Nine preterm infants born between 28 2/7 and 31 4/7 weeks of gestation during their first 14 days of life.


METHODS
Pain was assessed by the Bernese Pain Scale for Neonates (BPSN), the Premature Infant Pain Profile (PIPP) and the Visual Analogue Scale (VAS). Salivary cortisol was analysed.


RESULTS
72-94% of the variability was within-subject variability, indicating inconsistency of pain responses across the 5 heel sticks. Interrater agreement was highest during heel sticks 1-3 and decreased during heel stick 4 and 5, indicating a possible alteration of pain patterns. No significant differences in the amount of cortisol could be detected before and after the heel sticks (p = 0.55), indicating no stress-induced peak after the painful intervention. However, a general gradual decrease of cortisol levels across time could be detected.


CONCLUSIONS
A high variability in pain response among preterm neonates across time could be described. Consistency of cortisol levels before and after the heel sticks could indicate the effectiveness of sucrose across time.
Cignacco
E
E
Institute of Nursing Science, University of Basel, Basel, Switzerland. eva.cignacco@unibas.ch
Denhaerynck
K
K
Nelle
M
M
Bührer
C
C
Engberg
S
S
D005240:Feasibility Studies; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D007231:Infant, Newborn; D007234:Infant, Premature; D010146:Pain / Q000378:metabolism / Q000517:prevention & control*; D010147:Pain Measurement; D011677:Punctures / Q000009:adverse effects; D012463:Saliva / Q000378:metabolism; D013312:Stress, Physiological; D013395:Sucrose / Q000627:therapeutic use*; D013549:Sweetening Agents / Q000627:therapeutic use*
D013549:Sweetening Agents; D013395:Sucrose; D006854:Hydrocortisone