EDITORIAL For reprint orders, please contact: [email protected]
Acute to chronic postoperative pain in children: does it exist?
Jane C Ahn1
Michelle A Fortier1
The transition from acute to chronic pain after surgery is a well-studied clinical syndrome that was first described approximately 10 years ago. Since then, a substantial body of literature has evolved exploring this phenomenon in significant detail [1–7] . Known as chronic postoperative surgical pain (CPSP), this clinical entity is highly prevalent, reportedly affecting anywhere from 5 to 50% of adults recovering from surgery. According to the International Association for the Study of Pain, CPSP is a pain syndrome of at least 2 months’ duration, occurs postoperatively, and does not result from other causes such as chronic infection or pre-existing disease. Several predictive patient factors for developing CPSP in adults have been recognized, including the severity of acute postoperative pain, female gender, young age, obesity, preoperative anxiety, pain catastrophizing and a history of pre-existing pain. Acute postoperative pain has emerged as one of the strongest predictors of CPSP [8] . Furthermore, a number of surgical procedures associated with an increased risk of CPSP have been identified such as inguinal herniorrhaphy, thoracotomy, breast surgery
Zeev N Kain*1
“According to the International Association for the Study of Pain, chronic postoperative surgical pain (CPSP) is a pain syndrome of at least 2 months duration, occurs postoperatively, and does not result from other causes such as chronic infection or pre-existing disease.”
and limb amputation. Unfortunately, treatment of CPSP can be a challenging task for the healthcare provider and a difficult burden for the patient to bear. Not only may the patient suffer from significant negative functional and social impact, but there are substantially increased healthcare and economic costs incurred as well. Despite the breadth of evidence examining CPSP in adults, this is a relatively unstudied topic in the pediatric population. Little is known about CPSP in children: whether it even exists, the number of children affected, possible predisposing risk factors and the long-term impact of the disease. Because over 5 million children undergo surgery in the USA each year, the risk of developing CPSP in children is a very real and significant threat. It is reported that the majority of children suffer from clinically significant acute postoperative pain and that this pain is overwhelmingly undertreated, particularly in the home setting [9–15] . A review of the literature found two retrospective questionnaire studies examining the occurrence of CPSP in children [16,17] . These two studies enrolled adult patients who had surgery as children
“Little is known about CPSP in
children: whether it even exists, the number of children affected, possible predisposing risk factors and the long-term impact of the disease.”
Department of Anesthesiology & Perioperative Care at University of California, Irvine, 333 City Blvd W, Orange, CA, 92868, USA *Author for correspondence: Tel.: +1 714 456 6652; Fax: +1 714 456 7702; [email protected] 1
10.2217/PMT.12.48 © 2012 Future Medicine Ltd
Pain Manage. (2012) 2(5), 421–423
part of
ISSN 1758-1869
421
Editorial Ahn, Fortier & Kain
“All children who
reported chronic postoperative pain stated that their pain corresponded to their surgery site and the majority of children (85%) indicated that their pain began immediately after surgery.”
at an average of 17 years prior to enrolment. Participants were asked to recall the duration of their postoperative pain, whether it lasted more than 2 months, and if the pain was still present at the time of the study. These studies suggest an incidence rate between 2 and 16% of CPSP in children; however, we question the validity of these findings as they are dependent on recall of childhood memories that are nearly two decades old. Furthermore, recall of subjective childhood memories can easily be influenced by other physically painful and emotional life experiences that may have occurred since the time of the original surgery, resulting in significant recall bias. In response to the dearth of publications focused on CPSP in children, we recently conducted a cross-sectional study aimed at examining incidence rates of chronic pain in children following surgery [18] . Children between the ages of 2 and 17 years who had undergone general anesthesia for general, orthopedic and urologic surgeries in the preceding 10 months at a major children’s hospital were considered for the study. Interviews of children and their parents occurred no earlier than 3 months after surgery to avoid possible overlap between acute and chronic postoperative pain. Of 113 participants who were recruited, 15 (13.3%) reported chronic pain related to surgery with a median duration of just over 4 months. A number of these children reported that their pain caused significant functional disturbances in myriad areas, including academic, social, household, extracurricular activities and sleep. All children who reported chronic postoperative pain stated that their pain corresponded to their surgery site and the majority of children (85%) indicated that their pain began immediately after surgery. The average pain level reported was 4.2 ± 1.5 on a 0–10 numeric pain-rating scale. Although this study is the first of its kind to establish the existence of CPSP in children, there were several limitations to note. First, we included a wide range of surgical procedures and patient ages, which makes it difficult to identify specific risk factors for CPSP in children. Furthermore, data were
References 1
2
422
Kehlet H, Rathmell JP. Persistent postsurgical pain: the path forward through better design of clinical studies. Anesthesiology 112(3), 514–515 (2010). Perkins FM, Kehlet H. Chronic pain as an outcome of surgery: a review of predictive
gathered retrospectively, and although we limited the time frame to less than 1 year after the surgery, there is still the possibility of recall bias. Due to its potentially widespread debilitating effects and ability to affect hundreds of thousands of children annually, CPSP in children is a relatively unknown phenomenon that warrants further examination. Our data indicate that CPSP does in fact occur in children at a rate of approximately 13%; however, further studies must be conducted in order to corroborate our results. Ideally, prospective longitudinal studies with long-term follow-up are needed to better elucidate the incidence at which CPSP develops. Further areas of interest that need additional clarification include the impact of functional and social disability that may occur, factors that may predispose to the development of CPSP (e.g., preoperative anxiety, history of pre-existing pain, parent and child pain catastrophizing, and intensity of acute postoperative pain), and environmental risks such as type of surgery. A better understanding of this syndrome in the pediatric population will ultimately enable the healthcare provider to more adequately treat, attenuate and possibly prevent the development of CPSP. Nonetheless, given the adult literature that largely points to inadequately managed acute postoperative pain as a highly significant risk factor for CPSP and the substantial body of literature highlighting the suboptimal management of children’s postoperative pain in the home setting, it is clear that a major avenue for prevention of CPSP is to improve management of children’s postoperative pain by parents. Financial & competing interests disclosure The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties. No writing assistance was utilized in the production of this manuscript.
factors. Anesthesiology. 93, 1123–1133 (2000). 3
Macrae WA. Chronic post-surgical pain: 10 years on. Br. J. Anaesth. 101(1), 77–86 (2008).
4
Kehlet H, Jensen TS, Woolf C. Persistent postsurgical pain: risk factors and
Pain Manage. (2012) 2(5)
prevention. Lancet 367, 1618–1625 (2006). 5
Gramke HF, de Rijke JM, van Kleef M et al. The prevalence of postoperative pain in a cross-sectional group of patients after day-case surgery in a university hospital. Clin. J. Pain 23(6), 543–548 (2007).
future science group
Acute to chronic postoperative pain in children: does it exist? 6
Pavlin DJ, Sullivan MJ, Freund PR, Roesen K. Catastrophizing: a risk factor for postsurgical pain. Clin. J. Pain 21(1), 83–90 (2005).
11
Hamers JP, Abu-Saad HH. Children’s pain at home following (adeno) tonsillectomy. Eur. J. Pain 6, 213–219 (2002).
7
Aasvang E, Kehlet H. Chronic postoperative pain: the case of inguinal herniorrhaphy. Br. J. Anaesth. 95(1), 69–76 (2005).
12 Kankkunen P, Vehvilainen-Julkunen K,
15
Fortier MA, MacLaren JE, Martin SR, Perret D, Kain ZN. Pediatric pain after ambulatory surgery: where’s the medication? Pediatrics 124(4), e588–e595 (2009).
16
Kristensen AD, Pedersen TA, Hjortdal VE, Jensen TS, Nikolajsen L. Chronic pain in adults after thoracotomy in childhood or youth. Br. J. Anaesth. 104(1), 75–79 (2010).
Voepel-Lewis T, Tait AR. Pain relief in children following outpatient surgery. J. Clin. Anesth. 11, 187–191 (1999).
17
Aasvang EK, Kehlet H. Chronic pain after childhood groin hernia repair. J. Pediatr. Surg. 42(8), 1403–1408 (2007).
Warnock FF, Lander J. Pain progression, intensity and outcomes following tonsillectomy. Pain 75(1), 37–45 (1998).
18
Fortier MA, Chou J, Maurer EL, Kain ZN. Acute to chronic postoperative pain in children: preliminary findings. J. Pediatr. Surg. 46(9), 1700–1705 (2011).
Pietila AM, Kokki H, Halonen P. Parents’ perceptions and use of analgesics at home after children’s day surgery. Paediatr. Anaesth. 13, 132–140 (2003).
8
Macrae WA. Chronic pain after surgery. Br. J. Anaesth. 87(1), 88–98 (2001).
9
Cummings EA, Reid GJ, Finley GA, McGrath PJ, Ritchie JA. Prevalence and source of pain in pediatric inpatients. Pain 68(1), 25–31 (1996).
13 Munro HM, Malviya S, Lauder GR,
10
Finley GA, McGrath PJ, Forward SP, McNeill G, Fitzgerald P. Parents’ management of children’s pain following ‘minor’ surgery. Pain 64(1), 83–87 (1996).
14
future science group
Editorial
www.futuremedicine.com
423
Acute to chronic postoperative pain in children: does it exist?
Jane C Ahn1
Michelle A Fortier1
The transition from acute to chronic pain after surgery is a well-studied clinical syndrome that was first described approximately 10 years ago. Since then, a substantial body of literature has evolved exploring this phenomenon in significant detail [1–7] . Known as chronic postoperative surgical pain (CPSP), this clinical entity is highly prevalent, reportedly affecting anywhere from 5 to 50% of adults recovering from surgery. According to the International Association for the Study of Pain, CPSP is a pain syndrome of at least 2 months’ duration, occurs postoperatively, and does not result from other causes such as chronic infection or pre-existing disease. Several predictive patient factors for developing CPSP in adults have been recognized, including the severity of acute postoperative pain, female gender, young age, obesity, preoperative anxiety, pain catastrophizing and a history of pre-existing pain. Acute postoperative pain has emerged as one of the strongest predictors of CPSP [8] . Furthermore, a number of surgical procedures associated with an increased risk of CPSP have been identified such as inguinal herniorrhaphy, thoracotomy, breast surgery
Zeev N Kain*1
“According to the International Association for the Study of Pain, chronic postoperative surgical pain (CPSP) is a pain syndrome of at least 2 months duration, occurs postoperatively, and does not result from other causes such as chronic infection or pre-existing disease.”
and limb amputation. Unfortunately, treatment of CPSP can be a challenging task for the healthcare provider and a difficult burden for the patient to bear. Not only may the patient suffer from significant negative functional and social impact, but there are substantially increased healthcare and economic costs incurred as well. Despite the breadth of evidence examining CPSP in adults, this is a relatively unstudied topic in the pediatric population. Little is known about CPSP in children: whether it even exists, the number of children affected, possible predisposing risk factors and the long-term impact of the disease. Because over 5 million children undergo surgery in the USA each year, the risk of developing CPSP in children is a very real and significant threat. It is reported that the majority of children suffer from clinically significant acute postoperative pain and that this pain is overwhelmingly undertreated, particularly in the home setting [9–15] . A review of the literature found two retrospective questionnaire studies examining the occurrence of CPSP in children [16,17] . These two studies enrolled adult patients who had surgery as children
“Little is known about CPSP in
children: whether it even exists, the number of children affected, possible predisposing risk factors and the long-term impact of the disease.”
Department of Anesthesiology & Perioperative Care at University of California, Irvine, 333 City Blvd W, Orange, CA, 92868, USA *Author for correspondence: Tel.: +1 714 456 6652; Fax: +1 714 456 7702; [email protected] 1
10.2217/PMT.12.48 © 2012 Future Medicine Ltd
Pain Manage. (2012) 2(5), 421–423
part of
ISSN 1758-1869
421
Editorial Ahn, Fortier & Kain
“All children who
reported chronic postoperative pain stated that their pain corresponded to their surgery site and the majority of children (85%) indicated that their pain began immediately after surgery.”
at an average of 17 years prior to enrolment. Participants were asked to recall the duration of their postoperative pain, whether it lasted more than 2 months, and if the pain was still present at the time of the study. These studies suggest an incidence rate between 2 and 16% of CPSP in children; however, we question the validity of these findings as they are dependent on recall of childhood memories that are nearly two decades old. Furthermore, recall of subjective childhood memories can easily be influenced by other physically painful and emotional life experiences that may have occurred since the time of the original surgery, resulting in significant recall bias. In response to the dearth of publications focused on CPSP in children, we recently conducted a cross-sectional study aimed at examining incidence rates of chronic pain in children following surgery [18] . Children between the ages of 2 and 17 years who had undergone general anesthesia for general, orthopedic and urologic surgeries in the preceding 10 months at a major children’s hospital were considered for the study. Interviews of children and their parents occurred no earlier than 3 months after surgery to avoid possible overlap between acute and chronic postoperative pain. Of 113 participants who were recruited, 15 (13.3%) reported chronic pain related to surgery with a median duration of just over 4 months. A number of these children reported that their pain caused significant functional disturbances in myriad areas, including academic, social, household, extracurricular activities and sleep. All children who reported chronic postoperative pain stated that their pain corresponded to their surgery site and the majority of children (85%) indicated that their pain began immediately after surgery. The average pain level reported was 4.2 ± 1.5 on a 0–10 numeric pain-rating scale. Although this study is the first of its kind to establish the existence of CPSP in children, there were several limitations to note. First, we included a wide range of surgical procedures and patient ages, which makes it difficult to identify specific risk factors for CPSP in children. Furthermore, data were
References 1
2
422
Kehlet H, Rathmell JP. Persistent postsurgical pain: the path forward through better design of clinical studies. Anesthesiology 112(3), 514–515 (2010). Perkins FM, Kehlet H. Chronic pain as an outcome of surgery: a review of predictive
gathered retrospectively, and although we limited the time frame to less than 1 year after the surgery, there is still the possibility of recall bias. Due to its potentially widespread debilitating effects and ability to affect hundreds of thousands of children annually, CPSP in children is a relatively unknown phenomenon that warrants further examination. Our data indicate that CPSP does in fact occur in children at a rate of approximately 13%; however, further studies must be conducted in order to corroborate our results. Ideally, prospective longitudinal studies with long-term follow-up are needed to better elucidate the incidence at which CPSP develops. Further areas of interest that need additional clarification include the impact of functional and social disability that may occur, factors that may predispose to the development of CPSP (e.g., preoperative anxiety, history of pre-existing pain, parent and child pain catastrophizing, and intensity of acute postoperative pain), and environmental risks such as type of surgery. A better understanding of this syndrome in the pediatric population will ultimately enable the healthcare provider to more adequately treat, attenuate and possibly prevent the development of CPSP. Nonetheless, given the adult literature that largely points to inadequately managed acute postoperative pain as a highly significant risk factor for CPSP and the substantial body of literature highlighting the suboptimal management of children’s postoperative pain in the home setting, it is clear that a major avenue for prevention of CPSP is to improve management of children’s postoperative pain by parents. Financial & competing interests disclosure The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties. No writing assistance was utilized in the production of this manuscript.
factors. Anesthesiology. 93, 1123–1133 (2000). 3
Macrae WA. Chronic post-surgical pain: 10 years on. Br. J. Anaesth. 101(1), 77–86 (2008).
4
Kehlet H, Jensen TS, Woolf C. Persistent postsurgical pain: risk factors and
Pain Manage. (2012) 2(5)
prevention. Lancet 367, 1618–1625 (2006). 5
Gramke HF, de Rijke JM, van Kleef M et al. The prevalence of postoperative pain in a cross-sectional group of patients after day-case surgery in a university hospital. Clin. J. Pain 23(6), 543–548 (2007).
future science group
Acute to chronic postoperative pain in children: does it exist? 6
Pavlin DJ, Sullivan MJ, Freund PR, Roesen K. Catastrophizing: a risk factor for postsurgical pain. Clin. J. Pain 21(1), 83–90 (2005).
11
Hamers JP, Abu-Saad HH. Children’s pain at home following (adeno) tonsillectomy. Eur. J. Pain 6, 213–219 (2002).
7
Aasvang E, Kehlet H. Chronic postoperative pain: the case of inguinal herniorrhaphy. Br. J. Anaesth. 95(1), 69–76 (2005).
12 Kankkunen P, Vehvilainen-Julkunen K,
15
Fortier MA, MacLaren JE, Martin SR, Perret D, Kain ZN. Pediatric pain after ambulatory surgery: where’s the medication? Pediatrics 124(4), e588–e595 (2009).
16
Kristensen AD, Pedersen TA, Hjortdal VE, Jensen TS, Nikolajsen L. Chronic pain in adults after thoracotomy in childhood or youth. Br. J. Anaesth. 104(1), 75–79 (2010).
Voepel-Lewis T, Tait AR. Pain relief in children following outpatient surgery. J. Clin. Anesth. 11, 187–191 (1999).
17
Aasvang EK, Kehlet H. Chronic pain after childhood groin hernia repair. J. Pediatr. Surg. 42(8), 1403–1408 (2007).
Warnock FF, Lander J. Pain progression, intensity and outcomes following tonsillectomy. Pain 75(1), 37–45 (1998).
18
Fortier MA, Chou J, Maurer EL, Kain ZN. Acute to chronic postoperative pain in children: preliminary findings. J. Pediatr. Surg. 46(9), 1700–1705 (2011).
Pietila AM, Kokki H, Halonen P. Parents’ perceptions and use of analgesics at home after children’s day surgery. Paediatr. Anaesth. 13, 132–140 (2003).
8
Macrae WA. Chronic pain after surgery. Br. J. Anaesth. 87(1), 88–98 (2001).
9
Cummings EA, Reid GJ, Finley GA, McGrath PJ, Ritchie JA. Prevalence and source of pain in pediatric inpatients. Pain 68(1), 25–31 (1996).
13 Munro HM, Malviya S, Lauder GR,
10
Finley GA, McGrath PJ, Forward SP, McNeill G, Fitzgerald P. Parents’ management of children’s pain following ‘minor’ surgery. Pain 64(1), 83–87 (1996).
14
future science group
Editorial
www.futuremedicine.com
423
