Assessment of Neonatal Pain During Heel Prick: Lancet vs Needle-A Randomized Controlled Study

Background: Heel prick is a frequent painful procedure in newborns. A lancet or a 26-gauge needle is used for a heel prick in India.

Objective: To compare the pain caused by heel prick with a lancet or a 26-gauge needle in newborns admitted in the neonatal intensive care unit (NICU) using the preterm infant pain profile (PIPP).

Methods: This randomized controlled trial was conducted over 2 months in a Level III NICU with a sample size of 40 subjects (20 in each group), which was required for the study to have a power of 80% with an alpha error of 0.05. Hemodynamically stable newborns on at least those on partial oral feeds undergoing heel prick for routine glucose monitoring were randomized into two groups within 48 h of NICU admission after informed parental consent: heel prick with a lancet or with a 26-gauge needle using computer-generated random numbers. Two milliliters of expressed breast milk was given 2 min before the heel prick. Pain before, during and after (1 and 5 min) was assessed using the PIPP score. The primary outcome measure was the PIPP score. The secondary outcome measures were the duration of audible cry and the number of pricks needed for an adequate sample. Statistical analysis was done using the Mann Whitney U test and Friedman's test on SPSS v.21. A p value of < 0.05 was significant.

Results: There were 40 neonates, 24 males and 16 females included in the study with a median age of 7 days. The mean birth weight was 2441 g (SD: 699) at a mean gestation of 34.4 weeks (SD: 3.2). The median PIPP scores at 0-30 s after heel prick were 7.05 ± 3.57 with a lancet vs. 9.35 ± 3.68 a needle (p = 0.052). There was a significantly lower duration of audible cry with use of lancet (10.5 ± 18.5 s vs. 75.2 ± 12.0 s with needle; p = 0.03). All heel pricks resulted in adequate sampling.

Conclusion: Heel prick with a lancet causes less crying than a 26-gauge needle, though the PIPP scores are not significantly different.