Improvements in neonatal care have led to improved mortality and morbidity rates. An increased number of infants that are born more prematurely are being treated for prolonged time periods in the neonatal care units. The care includes many procedures that might inflict pain on the newborn infants. Pain is a protective mechanism, but it can have negative short- and long-term consequences on vulnerable infants. In order to prevent and treat pain, reliable pain assessment is needed. The aim of this research was to improve pain relief at blood sampling in the neonatal period, by non-pharmacological methods, and to investigate skin conductance as a pain assessment tool in newborn infants.
Study I was a randomised trial with 120 infants divided into four groups, who received 1 ml 10% glucose, 30% glucose, breast milk or no solution, orally, two minutes prior to the heel-stick. In the group given 30% glucose the crying time was significantly shorter than in the control group. Significantly fewer infants in the 30% glucose group did not cry at all, and the heart rate increased less in that group than in the control group.
Study II was a randomised trial with 120 infants divided into four groups, undergoing blood sampling with either heel-stick or veneplmcture and receiving 1 ml 30% glucose orally, or no fluid, prior to the painful event. The crying time was significantly shorter and PIPP pain score lower in the venepuncture group than in the heel-stick group when no glucose was given. When glucose was given, PIPP score was lower in both glucose groups than in the groups without glucose, but no difference was seen between the two glucose groups. Crying time in the glucose group was shorter than ill the group without glucose when heel-stick was performed.
In study III we used a randomised controlled double-blind design. Two hundred and one infants were randomly allocated to one of two groups receiving either 0.5 g EMLA® on the dorsum ofthehandfor 60 minutes followed by a recovery period of 15 min, and 1 ml sterile water in the mouth 2 min prior to venepuncture, or 0.5 ml placebo cream on the hand and 1 ml 30% glucose orally. PIPP scores were lower in the glucose group and fewer infants were scored as having pain (PIPP > 6). Crying time during the first 3 ruin was shorter in the glucose group.
Study IV was designed in a randomised, controlled double-blind way, where 57 infants were divided into two groups, receiving either 1 ml sterile water or 30% glucose three times daily for 3-5 days. Before undergoing routine blood sampling all infants had 1 ml 30% glucose instilled in the mouth. There was no difference in PIPP score, crying time or heart rate increase between the groups.
In study V galvanic skin response and other pain assessment methods were investigated in 32 infants during three procedures performed in a randomised order: 1) gently touching an ann or a leg (no stress or pain), 2) putting a alcohol-soaked cloth on the tnmk skin (stress) and 3) performing heel-stick for routine blood sampling (pain). GSR conductance level increased more in the painful than in the stressing situation. Number of waves and amplitude of the waves increased more during pain than during touching. Crying time was higher dming the painful situation than during the stressful intervention and PIPP was higher during pain than during touching and stress.
In conclusion, we found that 1 ml 30% glucose reduces pain signs from heel-stick and from venepuncture in neonates. Glucose does this better than EMLA ® cream and the effect is better than that of changing from heel-stick to venepuncture. Repeated administration of 1 ml 30% glucose for 3-5 days does not decrease the pain relieving effect.
GSR can contribute to differentiate pain from stress but more research is needed to achieve a clinically useful application.
Linköping: Linköpings universitet , 2003. , 67 p.
2004-01-16, Wilandersalen, Universitetssjukhuset, Linköping, 09:15 (Swedish)