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Paediatric acute pain is different from adult acute pain
Guest Editorial
Paediatric acute pain is different from adult acute pain Patrick J McGrath, PhD G A l l e n Finley, M D F R C P C
Paediatric acute pain is, in some ways, similar to acute pain in adults. By and large, the same drugs are used and, after the n e o n a t a l period, most d r u g dosages are similar ff one takes account of body size. Moreover, the causes of most acute pain, unlike chronic pain, are the same in children and adults. H o w e v e r , a d u l t a n d p a e d i a t r i c pain differ in i m p o r t a n t ways d u e t o c o g n i t i v e , social, a n d biological development. Consequently, results from a d u l t studies a n d p r a c t i c e c a n n o t always be extrapolated to paediatrics. From a pain management perspective, perhaps the m o s t i m p o r t a n t d i f f e r e n c e b e t w e e n adults and children is that most children younger than about ten years do not have a full understanding of why the doctors and nurses, w h o are supposed to make them better, are causing t h e m pain. It is surprising that children cooperate as much as they do with painful
investigations and other treatments are even more d i f f i c u l t for a c h i l d t o u n d e r s t a n d . N e g a t i v e experiences may cause medical fears, and pharmacological and psychological treatment for pain not only appears to reduce pain, but also to significantly increase children's positive attitudes and reduce their anxiety about future procedures. Thus, in order to reduce pain and suffering and to prevent anxiety about future medical encounters, needle procedures s h o u l d be d o n e o n l y w h e n n e c e s s a r y and pain management methods (either distraction or topical anaesthetic, w h i c h are both effective) should be a standard of care. In general, distraction in children cannot be serf-initiated, but requires a coach. Usually, the close involvement of a parent is needed, and most paedlatric centres encourage parents' participation.
and a broader range of pain is e x p e r i e n c e d w i t h increasing age, the perception of severity of pain and
A second difference due to cognitive factors is that neonates, infants and young children cannot directly tell us how much pain they are feeling, so that self r e p o r t i n g is usually not a useful m e t h o d of pain measurement. However, in the last ten years, sophis ticated behavioural measurements using detailed coding of facial responses 2 and social and appetitive behaviours 3 have been developed and validated. In
the behavioural response to pain from needles and other brief procedures is reduced. 1 Pain from needles is what children rerrmmber most about their medical encounters. Because of children's sensitivity to brief episodes of pain or discomfort, routes o f analgesic a d m i n i s t r a t i o n must also be c o n s i d e r e d m o r e c a r e f u l l y in p a e d i a t r i c pain management. Analgesic injections are, from a child's
addition, measures c o m b i n i n g biological and behavioural measures are n o w available even for neonates. 4 A recent monograph has reviewed the full range of paediatric pain measures. 5 A final difference due to cognitive development is that paediatric patients are unable to advocate for more appropriate pain management. Infants cannot write letters to complain about their care (on the
point of view, almost always worse than the pain they are d e s i g n e d to help, and the needles used for
other hand, adults don't complain enough). Children's pain has not always been taken seriously and it was
medical procedures. Y o u n g c h i l d r e n live in the m o m e n t and cannot understand the concept of 'pain n o w for health later'. For a young child, the pain of a needle lasts an eternity. As understanding develops
n o t u n u s u a l for children to have major s u r g e r y w i t h o u t a n a e s t h e s i a o n l y a d o z e n years ago.6. T
From the departments of Psychology and Anaesthesia, Dalhousle University Peddatrlc Pain Service, I~I< Grace Health Centre Halifax, Nova Scotia, Canada. Drs Patrick McGrath and G. Allen Flnlay are editors and publishers of the Pediatric Pain Letter.
A c u t e Pain
Fortunately, the situation has changed and now the only surgery done frequently without anaesthesia is c i r c u m c i s i o n . U n a n a e s t h e t i s e d c i r c u m c i s i o n is performed out of ignorance and habit, not because there aren't good anaesthetic techniques available. 8
V o l u m e 3 (1) M a r c h 2000
5
Biological differences are critically important in the dosages of pain medication for neonates and infants. Because of differences in renal clearance and p e r m e ability o f the b l o o d brain barrier, n e o n a t e s m a y require smaller doses of some analgesics and a n a e s t h e t i c s t h a n d o c h i l d r e n o r adults. T h e s e differences decrease as the child matures, so that, in most situations, infants of even a few months o f age have a dosage by weight similar to older children and y o u n g adults. It has been suggested that y o u n g children may have less p o s t o p e r a t i v e p a i n t h a n o l d e r c h i l d r e n . 9 H o w e v e r , intensity and d u r a t i o n o f pain are b o t h significant factors in a child's experience. While the d u r a t i o n o f postoperative pain m a y be shorter in y o u n g c h i l d r e n , d u e t o t h e b i o l o g i c a l effect o f quicker healing, there is no evidence that they have a lower peak level of pain. An i n t e r e s t i n g a n d i n c r e a s i n g l y u t i l i s e d developmental anomaly is that sucrose (sweet taste) has a significant opioid receptor mediated analgesic effect in infants and y o u n g children, m,ll although it seems to lose its analgesic effect in chilclhoock Studies examining the repeated use of sweet taste in neonates are underway. Cenlxal sensitisation may be m o r e powerful in the developing child 12 than in adults, but there are n o c o m p a r a t i v e data. T a d d i o et at have s h o w n t h a t healthy infant boys, w h o experienced significant pain after birth (from circumcision), were m o r e sensitive than peers w h o were not circumcised or w h o were protected from the pain of circumcision, w h e n they were i m m u n i s e d months later. Therefore, failure to prevent or manage pain in infants may have long t e r m consequences. I n s u m m a r y , a l t h o u g h t h e r e are s u b s t a n t i a l differences between acute pain assessment and management in c h i l d r e n a n d in a d u l t s , t h e c o m m o n a l i t y is greater. T h e i m p o r t a n c e o f pain m a n a g e m e n t in children is paramount, and paediatric and adult researchers and practitioners can learn a
References 1.
2.
3.
4.
5. 6.
7.
Fradet C, McGrath PJ, Kay J, Adams S, Luke B. A prospective survey of reactions to blood tests by children and adolescents. Pa/n 1990; 40:53 60. G r u n a u R V E , C r a i g K D . Pain e x p r e s s i o n in neonates: facial action and cry. Pain 1987; 28: 395410. Chambers CT, Reid G, McGrath PJ, Finley GA. D e v e l o p m e n t and p r e l i m i n a r y v a l i d a t i o n o f a postoperative pain measure for parents. Pain 1996; 68:307-313. Stevens B, Johnston CC, Petryshen P, Taddio A. Premature infant pain profile: D e v e l o p m e n t and initial validation. Cttn J Pain 1996; 12:13-22. Finley GA, McGrath PJ (Eds.) Measurement of Pain In Infants and Children. Seattle: IASP Press, 1998. A n a n d KJS, Sippell W G , A y n s l e y - G r e e n A. randomised trial of fentanyl anaesthesia in preterm babies undergoing surgery: Effects on the stress response. Lancet 1987; 1 (8524): 62-66 Anand KJS, Sippell W G , Schofield NM, AynsleyGreen A. Does halothane anaesthesia decrease the metabolic and endocrine stress response of newborn infants undergoing operations? BMJ 1988; 296: 668-
672. 8.
American Academy of Pediatrics, Task Force on C i r c u m c i s i o n . C i r c u m c i s i o n policy statement. Ped~atrtcs 1999; 103 (3): 686 693. 9. Leikin L, F i r e s t o n e P, M c G r a t h PJ. Physical s y m p t o m reporting in T y p e A and B children. Journal of Consulting and Clinical Psychology 1988; 56: 721-726. 10. Blass EM, Hoffmeyer LB. Sucrose as an analgesic for n e w b o m infants. Pediatrics 1991: 87:215 218. 11. Stevens B, Taddio A, Ohlsson A, Einarson T. The efficacy of sucrose for relieving procedural pain in neonates a systematic review and meta analysis. Aaa Pa~atrtca 1997; 86: 837-842.
12. Taddio A, Koren G, Ilersich AL. Effect of neonatal circumcision on pain response during subsequent routine vaccination. Lancet 1997; 349: 599-603.
great deal from each other.
6
V o l u m e 3 (1) M a r c h 2000
Acute Pain
Paediatric acute pain is different from adult acute pain Patrick J McGrath, PhD G A l l e n Finley, M D F R C P C
Paediatric acute pain is, in some ways, similar to acute pain in adults. By and large, the same drugs are used and, after the n e o n a t a l period, most d r u g dosages are similar ff one takes account of body size. Moreover, the causes of most acute pain, unlike chronic pain, are the same in children and adults. H o w e v e r , a d u l t a n d p a e d i a t r i c pain differ in i m p o r t a n t ways d u e t o c o g n i t i v e , social, a n d biological development. Consequently, results from a d u l t studies a n d p r a c t i c e c a n n o t always be extrapolated to paediatrics. From a pain management perspective, perhaps the m o s t i m p o r t a n t d i f f e r e n c e b e t w e e n adults and children is that most children younger than about ten years do not have a full understanding of why the doctors and nurses, w h o are supposed to make them better, are causing t h e m pain. It is surprising that children cooperate as much as they do with painful
investigations and other treatments are even more d i f f i c u l t for a c h i l d t o u n d e r s t a n d . N e g a t i v e experiences may cause medical fears, and pharmacological and psychological treatment for pain not only appears to reduce pain, but also to significantly increase children's positive attitudes and reduce their anxiety about future procedures. Thus, in order to reduce pain and suffering and to prevent anxiety about future medical encounters, needle procedures s h o u l d be d o n e o n l y w h e n n e c e s s a r y and pain management methods (either distraction or topical anaesthetic, w h i c h are both effective) should be a standard of care. In general, distraction in children cannot be serf-initiated, but requires a coach. Usually, the close involvement of a parent is needed, and most paedlatric centres encourage parents' participation.
and a broader range of pain is e x p e r i e n c e d w i t h increasing age, the perception of severity of pain and
A second difference due to cognitive factors is that neonates, infants and young children cannot directly tell us how much pain they are feeling, so that self r e p o r t i n g is usually not a useful m e t h o d of pain measurement. However, in the last ten years, sophis ticated behavioural measurements using detailed coding of facial responses 2 and social and appetitive behaviours 3 have been developed and validated. In
the behavioural response to pain from needles and other brief procedures is reduced. 1 Pain from needles is what children rerrmmber most about their medical encounters. Because of children's sensitivity to brief episodes of pain or discomfort, routes o f analgesic a d m i n i s t r a t i o n must also be c o n s i d e r e d m o r e c a r e f u l l y in p a e d i a t r i c pain management. Analgesic injections are, from a child's
addition, measures c o m b i n i n g biological and behavioural measures are n o w available even for neonates. 4 A recent monograph has reviewed the full range of paediatric pain measures. 5 A final difference due to cognitive development is that paediatric patients are unable to advocate for more appropriate pain management. Infants cannot write letters to complain about their care (on the
point of view, almost always worse than the pain they are d e s i g n e d to help, and the needles used for
other hand, adults don't complain enough). Children's pain has not always been taken seriously and it was
medical procedures. Y o u n g c h i l d r e n live in the m o m e n t and cannot understand the concept of 'pain n o w for health later'. For a young child, the pain of a needle lasts an eternity. As understanding develops
n o t u n u s u a l for children to have major s u r g e r y w i t h o u t a n a e s t h e s i a o n l y a d o z e n years ago.6. T
From the departments of Psychology and Anaesthesia, Dalhousle University Peddatrlc Pain Service, I~I< Grace Health Centre Halifax, Nova Scotia, Canada. Drs Patrick McGrath and G. Allen Flnlay are editors and publishers of the Pediatric Pain Letter.
A c u t e Pain
Fortunately, the situation has changed and now the only surgery done frequently without anaesthesia is c i r c u m c i s i o n . U n a n a e s t h e t i s e d c i r c u m c i s i o n is performed out of ignorance and habit, not because there aren't good anaesthetic techniques available. 8
V o l u m e 3 (1) M a r c h 2000
5
Biological differences are critically important in the dosages of pain medication for neonates and infants. Because of differences in renal clearance and p e r m e ability o f the b l o o d brain barrier, n e o n a t e s m a y require smaller doses of some analgesics and a n a e s t h e t i c s t h a n d o c h i l d r e n o r adults. T h e s e differences decrease as the child matures, so that, in most situations, infants of even a few months o f age have a dosage by weight similar to older children and y o u n g adults. It has been suggested that y o u n g children may have less p o s t o p e r a t i v e p a i n t h a n o l d e r c h i l d r e n . 9 H o w e v e r , intensity and d u r a t i o n o f pain are b o t h significant factors in a child's experience. While the d u r a t i o n o f postoperative pain m a y be shorter in y o u n g c h i l d r e n , d u e t o t h e b i o l o g i c a l effect o f quicker healing, there is no evidence that they have a lower peak level of pain. An i n t e r e s t i n g a n d i n c r e a s i n g l y u t i l i s e d developmental anomaly is that sucrose (sweet taste) has a significant opioid receptor mediated analgesic effect in infants and y o u n g children, m,ll although it seems to lose its analgesic effect in chilclhoock Studies examining the repeated use of sweet taste in neonates are underway. Cenlxal sensitisation may be m o r e powerful in the developing child 12 than in adults, but there are n o c o m p a r a t i v e data. T a d d i o et at have s h o w n t h a t healthy infant boys, w h o experienced significant pain after birth (from circumcision), were m o r e sensitive than peers w h o were not circumcised or w h o were protected from the pain of circumcision, w h e n they were i m m u n i s e d months later. Therefore, failure to prevent or manage pain in infants may have long t e r m consequences. I n s u m m a r y , a l t h o u g h t h e r e are s u b s t a n t i a l differences between acute pain assessment and management in c h i l d r e n a n d in a d u l t s , t h e c o m m o n a l i t y is greater. T h e i m p o r t a n c e o f pain m a n a g e m e n t in children is paramount, and paediatric and adult researchers and practitioners can learn a
References 1.
2.
3.
4.
5. 6.
7.
Fradet C, McGrath PJ, Kay J, Adams S, Luke B. A prospective survey of reactions to blood tests by children and adolescents. Pa/n 1990; 40:53 60. G r u n a u R V E , C r a i g K D . Pain e x p r e s s i o n in neonates: facial action and cry. Pain 1987; 28: 395410. Chambers CT, Reid G, McGrath PJ, Finley GA. D e v e l o p m e n t and p r e l i m i n a r y v a l i d a t i o n o f a postoperative pain measure for parents. Pain 1996; 68:307-313. Stevens B, Johnston CC, Petryshen P, Taddio A. Premature infant pain profile: D e v e l o p m e n t and initial validation. Cttn J Pain 1996; 12:13-22. Finley GA, McGrath PJ (Eds.) Measurement of Pain In Infants and Children. Seattle: IASP Press, 1998. A n a n d KJS, Sippell W G , A y n s l e y - G r e e n A. randomised trial of fentanyl anaesthesia in preterm babies undergoing surgery: Effects on the stress response. Lancet 1987; 1 (8524): 62-66 Anand KJS, Sippell W G , Schofield NM, AynsleyGreen A. Does halothane anaesthesia decrease the metabolic and endocrine stress response of newborn infants undergoing operations? BMJ 1988; 296: 668-
672. 8.
American Academy of Pediatrics, Task Force on C i r c u m c i s i o n . C i r c u m c i s i o n policy statement. Ped~atrtcs 1999; 103 (3): 686 693. 9. Leikin L, F i r e s t o n e P, M c G r a t h PJ. Physical s y m p t o m reporting in T y p e A and B children. Journal of Consulting and Clinical Psychology 1988; 56: 721-726. 10. Blass EM, Hoffmeyer LB. Sucrose as an analgesic for n e w b o m infants. Pediatrics 1991: 87:215 218. 11. Stevens B, Taddio A, Ohlsson A, Einarson T. The efficacy of sucrose for relieving procedural pain in neonates a systematic review and meta analysis. Aaa Pa~atrtca 1997; 86: 837-842.
12. Taddio A, Koren G, Ilersich AL. Effect of neonatal circumcision on pain response during subsequent routine vaccination. Lancet 1997; 349: 599-603.
great deal from each other.
6
V o l u m e 3 (1) M a r c h 2000
Acute Pain