Review: venepuncture is less painful than heel lance for blood sampling in neonates
Dr V Shah, Mount Sinai Hospital, Toronto, Ontario, Canada;
Is venepuncture less painful than heel lance for blood sampling in healthy neonates?
Studies selected compared venepuncture and heel lance for blood sampling in healthy term neonates. Outcomes were neonatal pain response (assessed by a validated measure), maternal anxiety, sampling time, and need for repeat skin puncture.
Medline, CINAHL, and EMBASE/Excerpta Medica (to Jun 2007); Cochrane Central Register of Controlled Trials (Issue 2, 2007); and reference lists were searched for randomised controlled trials (RCTs) or quasi-randomised trials. 5 RCTs (n = 317, 47–59% boys) met the selection criteria. All trials had adequate allocation concealment; in no trial were investigators or participants blinded, but the outcome assessor was blinded in 2 RCTs.
Various methods of pain assessment were used; all showed that neonatal pain response was lower with venepuncture than with heel lance (table). 1 RCT (n = 27) showed that maternal anxiety before the procedure was higher in the venepuncture group, but maternally-rated infant pain was lower. Sampling time for venepuncture was 58 seconds longer than for heel lance in 1 RCT and 65 seconds shorter in another RCT (2 RCTs, n = 110; weighted mean difference −36 seconds, 95% CI −76 to 3). Neonates in the venepuncture group were less likely to require a repeat skin puncture (4 RCTs, n = 254; relative risk 0.30, CI 0.18 to 0.49).
Venepuncture is less painful than heel lance for blood sampling in healthy neonates.
Shah V, Ohlsson A. Venepuncture versus heel lance for blood sampling in term neonates. Cochrane Database Syst Rev 2007;(4):CD001452.
Sampling blood in infants using a heel lancet continues to be a painful procedure despite various pain reduction techniques. Venepuncture may offer a less painful alternative. The review by Shah and Ohlsson showed that venepuncture is less painful than heel lancing. However, the included studies involved multiple measures of pain, different sizes of lancets and needles for venepuncture, and up to 7 different individuals administering the procedure.
Importantly, 3 validated instruments were used to measure pain response. State of arousal at the time of stimulus is included in both the Neonatal Infant Pain Scale and Premature Infant Pain Profile and is a strength of these instruments. A study that was not included in this review showed that the most stressful component of heel lancing was the squeezing of the heel and not the actual tissue damaging phase1; nonetheless, this pain contributes to the overall pain response for heel lance when comparing the 2 interventions.
A subjective measure of maternal anxiety (a 3-point scale that had not been validated or deemed reliable) showed higher anxiety levels with venepuncture; however, this finding may be spurious and merits further investigation. The skill level of the phlebotomist certainly affects the total number of venepunctures and heel lances required, as well as sampling time. More research is needed to determine the effect of training of nurses and phlebotomists on the pain experienced by infants.
Shah and Ohlsson provide neonatal nurses with evidence to support the use of venepuncture over heel lance to decrease the pain of routine blood sampling in neonates. Consistently, duration of cry, first crying time, and proportion of neonates crying were less with venepuncture. The authors’ analyses suggest that if nurses used venepuncture instead of heel lance, for every 3 procedures, 1 additional heel stick could be avoided, decreasing not only pain but trauma as well.