ABSTRACT

Young children, far from feeling little or no pain, may indeed experience greater intensity of pain than adults. This is because pain in children differs qualitatively not quantitatively from that in adults.
It is becoming increasingly clear that the solution to the problem of paeditric postoperative pain management lies not so much in the development of new techniques, as in the development of an oragnization to manipulate existing experitise based on team approach. Such Acute Pain Service (APS) is a part of a strategy to decrease perioperative morbidity and to reduce health care costs.
The American Style of APS is Anaesthesiologist – based to provide high quality analgesia by expensive high-tech pain management. On the other hand, the European Style encourages a cheaper Nurse-based- Anaesthesiologist- supervised approach.
By the start of the third millenium, much remains to be done in Egypt to design an appropriate APS for postoperative surgical patients including children, based on sound scientific foundations. The present review suggests an organization model, in detail, which addresses the difficult equation of Egypt, being a developing country with limited financial resources, lacking a wide-base of high-tech nursing staff and having hospitals of mostly multispeciality nature.
Such a suggested Egyptian organization model for paediatric APS, may open the door to other African pain authorities, with similar difficult equations, to introduce their own organization models.  Guided by the International Association for the Study of Pain (IASP), the interaction of these models might push to light an African Style for paediatric APS, side-by-side with the American and European Styles.

INTRODUCTION:
Surgery produces nociceptive input into the central nervous system (CNS) through afferent A and C fibres, caused by local tissue damage and direct nerve trauma, with subsequent release of sensitizing algogenic compounds and algesic mediators such as potassium, hydrogen ions, lactic acid, substance P (SP), bradykinin, prostaglandins, histamine and serotonin (1).  Their effects may well outlast the acute perioperative period by days and may evoke exaggerated changes in neuroplasticity, such as primary and secondary hyperalgesia and allodynia and may even initiate chronic pain syndrome (2).  Segmental and suprasegmental reflex responses, as well as cortical activation, initiate positive feedback loops via sympathetic and motor afferents, leading to continuing pain and to undesirable alterations in organ function (1).  Thus, undertreatment of postoperative pain may trigger impairments in pulmonary, cardiovascular, neuroendocrinal, gastrointestinal, immunological and metabolic functions (3-5).  
The psychological dimension of the experience of postoperative pain should be recognized because apprehensions, anxiety and insomnia may lead to anger which disturbs the relationship between the patient and the treating medical staff who are responsible to offer state-of-the-art perioperative pain control.

DO CHILDREN FEEL PAIN ?
The International Association for the Study of Pain (IASP) has defined pain as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.  Pain is always subjective; each individual learns the application of the word through experiences related to injury in early life”. (6)
Popular dogma has suggested that the human child does not feel pain, and that it is dangerous to give him powerful analgesia because of the risk of addiction (7).  The actual problem is that the child has a limited ability to communicate with adults and lacks relevant previous experience.  Cognitive and emotional developments together with psychological defense mechanisms are important variables to be considered with paediatric pain. (8)  The child may cope with pain by withdrawing, rather than crying for fear of the adult answer to that pain by the dreadful injection or the belief that he deserves the pain as a punishment for something he did wrong. (9)
Interest in the understanding and management of paediatric pain is increasing, and there are now available reviews and books covering the neurobiological, psychological and clinical aspects of this field (9-12).  The problem in that, while the importance of pain in infancy is becoming recognized, the understanding of the mechanisms underlying early pain processing is still rudimentary (13).  Schechter (14) has pointed out that the cycle of undertreatment can be broken by increased research, as undertreatment of pain in children is now widely acknowledged (14-16).  
There is a dimension to pain and tissue damage that is unique to paediatrics; pain being qualitatively but not quantitatively different from adults (13).  The developing CNS is particularly vulnerable to and can be permanently altered by tissue insult at critical stages of development. A study of neonates undergoing circumcision without analgesia suggested a long-lasting reduction in pain threshold (18).  Adequate treatment of early pain may well prevent long-term, potentially unwanted, sequelae to the developing CNS (19, 20).  However, some authors believe that early exposure to opioids may predispose to self-destructive behaviour in adolescents (21).  Aynsley-Green (7) comments that “we actually need evidence that the benefit from modulating the biochemical and hormonal sequelae of stress overweighs the risks of so doing, and that we are actually ignorant of the long-term sequelae of such treatment”.  Anyhow, Krane and Boltz, (22) recently hold the opinion that it would be considered malpractice and non-ethical to perform regional techniques in children who are not fully anaesthetized. 
Basically, it is unwise to extrapolate data from adult subjects on the function of the sensory pathways to the young individual (10).  Until we gain an adequate understanding of paediatric pain, we will be unable to design rational strategies for pain relief in infants and the clinical management of paediatric pain will remain much as it is now, largely imperical or even non-existent (13).

PAIN IN INFANCY AND CHILDREN:
At birth, the elements of the peripheral and central connections required for pain responses at spinal cord and brain stem level are present in the experimental rat, but the evidence shows that a considerable amount of development takes place postnatally, particularly in terms of formation of connections, maturation of transmitter systems, activation of descending and segmental controls and projection of sensation to higher centres in the brain (13).  
An inhibitory process is the maturation of descending inhibitory pathways travelling from the brain stem via the dorsolateral funiculus of the spinal cord to the dorsal horn (23).  This lack of descending inhibition means that there is no endogenous analgesia system to dampen noxious inputs as they enter the CNS and that their effects may, therefore, be more profound.  Another important mechanism is the changing function of inhibitory transmitters in the developing spinal cord.  Both gamma-aminobutyric acid (GABA) and glycine, the well-known fast inhibitory transmitters in the adult spinal cord, actually depolarize immature spinal neurones.  So, at early age, GABA and glycine appear to be major excitatory transmitters. Pain pathways especially thalamocortical radiations are also not well developed in early life, just as the development of the blood brain barrier  (7).  Diffuse distribution and high density of SP and N-methyl-D-aspartate (NMDA) receptors, with increased NMDA-induced increase in calcium influx, contribute in excitability (7) .  So, young children, far from feeling little or no pain, may indeed experience greater intensity of pain than adults (7, 13).

ASSESSMENT OF PAIN:
Finely et al (24) have recently reported that many types of the so-called “minor” surgery can cause significant pain in children and that parents have a number of misconceptions concerning pain treatment.  Many parents have false beliefs about addiction and proper use of acetaminophen and other analgesics (25). We have to admit that even hospitalized children are often treated inadequately for pain (26).  So, dynamic assessment of pain paves the way for its proper management in pediatrics.
Infants and children younger than two years are unable to communicate their pain and distress.  In this age group   ,  physiological (i.e. tachycardia, hypertension, tachypnea, palmar sweating, hypoxemia), and behavioural (i.e body movements, cries, facial expressions) responses are useful for the assessment of pain by postoperative Pain/Comfort Scale or Objective Pain Scale (27, 28).  Experienced nurses are better than trainees and parents are better than nurses in diagnosing paediatric pain versus other stresses.  As a matter of fact, discrimination between pain and distress may be very challenging particularly in the younger paediatric patients (6, 10).  
Re-assessment of the effectiveness of a pharmacological intervension in altering the pattern of the physiological and behavioural changes is very important (29). If re-assessment does not indicate improvement, then either the intervension has not been adequate, or the changes have not been due to pain in the first place.
In the non-paralyzed very young, pain free return to function and an ability to move appropriately should be the aim of management.  On the other-hand, in the paralyzed very young, pain occurs with intravenous cannulation, heel prick blood sampling, endotracheal intubation or airway suctioning.  Pre-empting of pain has the priority in management is such situations.
Children between the age of two and seven years, lack abstract thinking and the verbal skills necessary to express their pain intensity(30).  A number of projective methods have been evaluated to ascertain the presence of pain (and to a lesser degree its intensity) as inferred from the child’s selection of colour, drawing, or facial emotional expressions. Assessment can be done by physicians, nurses or parents.  The Faces Scale (Oucher Scale) is a practical ,reliable and easy to apply bedside guide for pain assessment in the young (31, 32).  It consists of a poster with six photographs of a child’s face in various expressions of pain, matched alongside a Visual Analogue Scale (VAS).  The Children’s Hospital of Eastern Ontaria Pain Scale (CHEOPS) includes six behaviours that are repeatedly observed by a trained observer(33).  The scale is a sensitive, valid and reliable behavioural measure of postoperative pain in children of such age group.
Children older than seven years, often have the ability to understand, rationalize and form relationships between cause and effect and they can often express their feelings and describe their pain experience (34, 35).  Therefore, they can self-report the quality and intensity of pain-within their age. Children’s verbal description of their pain can be assessed by simple numerical verbal rating scales. The VAS is the most extensively used because of its simplicity as children can mark a 10cm line with its length matching the rate of their pain intensity in a reliable and valid manner (36-38), at one end the word “no pain” and at the other end the words “pain as severe as possible”.
Pain ratings in this age group, can be also reliably assessed using an Analogue Chromatic Continuous Scale (ACCS), which allows grading of a child’s’ pain into a numeric value (39).  It consists of a slide ruler with graduated shades of red. The brightness of the colour represents the intensity of the pain.  The back of the ruler has a 10cm scale corresponding to the colour brightness. The child is asked to rate his or her pain by moving a sliding line indicator onto the appropriate colour. Thus, the choice of colour brightness directly quantifies pain intensity into a numeric value.  This is because sensory association relies upon colour choice, as most children associate pain with the red colour.
A new instrument provides practical clinical measure for assessing children’s pain intensity and pain affect (40).  It includes a Coloured Analogue Scale (CAS) to assess pain intensity and a Facial Affective Scale (FAS) to assess the aversive component of pain. Both scales have numerical ratings on the back, so that the administering person can quickly note the number that represents a child’s pain.
In using any tool for pain assessment the dynamic profile is the best for proper pain assessment and its subsequent management.

ACUTE PAIN SERVICES:

According to the IASP, acute pain service (APS) is “an inhospital organization which ensures optimal pain management for every patient who undergoes surgery including children and those undergoing surgery on ambulatory basis” (41).  It is becoming increasingly clear that the solution to the problem of postoperative pain management lies not so much in the development of new techniques as in the development of an organization to exploit existing expertise which is based on team approach (42).  This is one of the main conclusions and recommendations of interdisciplinary expert committee reports by National Health and Medical Research Council of Australia, Royal College of Surgeons of England and the College of Anaesthetists, U.S. Department of Health and Human Services, and the IASP. 

Goals and approach:
APS is a part of a strategy which prevents the postoperative injury response, a syndrome of hyperalgesia, inflammation, catabolism and physico-mental de-activation which causes slowing of recovery, increased perioperative morbidity and increased health care costs.
APS implies a combination of therapeutic techniques to optimize analgesia and to decrease drug toxicity and side-effects by balanced or multimodal approach.  In children, non-pharmacological methods of pain management are very important. (16)  While the most important of these is minimal separation from parents, other methods such as re-assurance, stroking and distraction may also be employed. (43)

Organization:
Organization of APS starts by initial planning for setting of its goals, identification of patient population to be served and the development of manpower resources and equipment.  Planning should include both initial and ongoing administration activities.  Education should be programmed for patients, anaesthetists, surgeons, nurses, pharmacists, psychologists and even physiotherapists.
Care should be standardized through specific guidelines which include patient selection, regular follow up,  the use of protocols, and the provision of a support system within the hospital which is capable of providing immediate airway management and ventilatory support once needed.
The proper organization should provide clear features efficient for attaining the goals of APS.  Sufficient trained staff members should cover 24 hour service per day.  Written protocols and guidelines should be prepared and well-explained to all APS staff.  Electronic monitoring should be available all the time for any patient.  There should be rapid response to paging together with an electronic data-base to facilitate patient tracking.  An adequate quality assurance program leads to improving the outcome of APS.
Organization models:
The American Style:
A postoperative pain management organization has been developing slowly in USA over the last years (44).  The organization is anaesthesia-based because of the needed experience to provide high quality analgesia by using high-technology pain management services, namely; epidural and patient controlled analgesia (PCA). Therefore, the American Society of Anaesthesiologists (ASA), (45), recommended the anaesthesiologists’  leadership of the APS organization for integrating pain management practices into the various aspects of perioperative care.  
Several studies on the quality of postoperative pain management, that utilized the American Style of APS have been reported (46-49). Miaskowski et al (50) in 1999 utilized a standardized approach to compare the quality of pain service to patients who were and who were not cared for by anaesthesia-based pain service.  Out of a total of 5837 patients, 49% were cared for by anaesthesiologist- based pain service. Patients who received pain service by anaesthesiologists were significantly more satisfied and reported significantly lower levels and intensity of pain in the postoperative period, with less pruritis, sedation or nausea, and were discharged sooner from the hospital.  The findings from this study demonstrated that the provided care had a significant impact on patient outcome.  However, although the implementation of anaesthesiologist-based APS has had a considerable impact on pain management on surgical wards, Rawal comments that not all patients received the benefits of such APS (42).  Rawal holds the opinion that a good APS organization is one which ensures optimal pain management for every patient who undergoes surgery including children and those undergoing surgery on ambulatory basis (42).  Furthermore, the record of USA – Style APS in implementing hospital-wide quality assurance measures has been generally unimpressive (42).  Additionally, the costs of USA-Style APS were very high accounting for $100-$300 per patient (41, 42).

The European Style:
For financial reasons, many countries restraint the American Style of APS.  It is becoming increasingly clear that simpler and less expensive models have to be developed if the aim is to improve the quality of postoperative analgesia for every patient who undergoes surgery including children and those undergoing surgery on ambulatory basis (42).
The European Style of APS, encourages a nurse-based-anaesthesiologist-supervised approach.  A specially trained Acute Pain Nurse (APN) makes daily rounds of all surgery departments.  She checks VAS recordings on charts, solves trouble-shooting technical difficulties and transfers problem patients to acute pain anaesthesiologists.  Day and night nurses are responsible for implementation of pain management guidelines and monitoring routines on the ward.  Encouraging the Europeans-Style and criticising the USA-Style of APS, Bridenbaugh (41) reported that the function of the anaesthesiologist should not be to run around the hospital filling up epidural catheters with various analgesic mixtures or setting infusion pumps, and that it would be far better for his time to be used in teaching or performing nerve blocks.  
Examples of European models of APS have been proposed from UK (51-53) Switzerland, Norway (54) and Sweden (42).  However, after the publication of a report by a joint working party of Royal College of Surgeons and College of Anaesthetists in 1990, there has been considerable interest in improving postoperative pain relief in the UK (42).  This has centered around the development of High Dependency Units (HDU’s), Acute Pain Teams (APT’s) and expansion in the use of techniques such as PCA.  On the other hand, Wheatly et al thinks that if complex analgesic techniques such as epidural, PCA or regional blocks are restricted to HDU’s, there would be little improvement in the quality of pain relief for the majority of patients undergoing surgery (53).
There seems to be an awakening of interest in establishing APS in European hospitals evident from a 17-nation European survey including Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UK (54).  Of the 105 hospitals surveyed only 37% (range 10-80%) had some kind of APS. The availability of special units for patients requiring prolonged pain relief by techniques such as epidural and PCA varied considerably. This survey also showed that anaesthesiologists had responsibilities for APS in 50%, an advisory role in 42% and no role at all in 8% of those hospitals.  None of the participating hospitals had anaesthesiologist-based comprehensive USA-Style APS (54).

A Suggested Egyptian Style:
By the start of the third millenium, much remains to be done to design an appropriate approach regimen for APS which has sound scientific foundations (7).
When suggesting a plan for APS in Egypt, it should be considered that Egypt is a developing country with limited financial resources and that high technology experienced nursing staff are not available on a wide scale to cover all the Egyptian hospitals characterized by a multispeciality nature.  In addition, a heavy goal of such a plan should aim to provide optimal management of postoperative pain for all patients including children and those undergoing surgery on ambulatory basis (1). 
A suggested plan for APS in Egypt, can solve such a difficult equation if it has the following features:

• Any method used for pain relief in the adult can be adapted for pain relief in the paediatric patient (8).  So, APS can cover postoperative care in both adults and children, in the multispeciality hospitals in Egypt.
• Prevention of pain and stress by proper preparation and patient premedication, must have a higher priority as a part of integrating every-day perioperative pain management, than is currently the case(7).  This needs the early involvement of anaesthetists and nurses together with scientific protocols for children (29).
• Pre-empting of pain by local analgesics or parenteral opioids or NSAID’s is a most logical and desirable way to share in the solution of the difficult equation.  The concept is that the application of the analgesic agent prior to the painful procedure shows a greater effect than its postoperative administration. Such pain reduction will outlast the duration of action expected from the agents’ pharmacological properties (1). 
• Simplicity equals safety: (27)
• simple measures such as “sucrose analgesia” are suitable for procedural pain in neonates as heel prick blood sampling (55).
• The emotional component of pain practice, using comforting measures, friendly surroundings, distraction techniques and giving the family the chance to be involved in assessment and pain control, should be respected. (29)  It should be clear that stress responses can be caused by stimuli other than pain including discomfort from hunger distress or illness in general (56). In so-doing the psychological dimention of perioperative paediatric pain is manipulated.
• A topical local anaesthetic mixture EMLA (Eutectic Mixture of Local Anaesthetics), can penetrate the skin for 5 mm depth, when covered with an occlusive dressing and left undisturbed for 60-90 minutes (57). As well, topical lidocaine 0.5% or bupivacaine 0.25-0.5% can be utilized during circumcision repair to provide effective postoperative analgesia(58).
• Non-opioid analgesics, usually acetaminophen and NSAID’s are useful for the treatment of mild-to-moderate pain such as in many ambulatory procedures, as well as for reducing the need for opioids in more severe pain. (59)
• Use of local and regional techniques:
• A routine perioperative use of topical, local or regional analgesia, alone or as a component of a multimodal approach with NSAID’s or acetaminophen is particularly useful (29, 60). 
• Bupivacaine 0.25-0.5% in a volume sufficient to fill the wound before its closure, gives analgesia equivalent to ilioinguinal nerve block (10). Ilioinguinal and iliohypogastric nerve blocks are useful for inguinal hernia repair, orchidopexy and hydrocele operations(61).
• The single injection caudal block, with placement of a catheter for continuous infusion of local anaesthetic with or without opioid may be needed. (10)  Whenever a single injection block can be extended, it should be preferred to a central neuro-axial block.
• In the PACU, specific cases may be managed by intermittent iv or epidural techniques which are equally effective and less hazardous than continuous techniques.  This should be achieved under the care of anaesthetists or APS  physicians in addition to specially trained nurses.

The organization model:
Health care and pain authorities in Egypt are advised to implement an organization APS model in increasingly scheduled numbers of multispeciality hospitals as well as specialized hospitals to achieve complete coverage according to a time-table.  Such an organization model depends on:

• Consideration of local factors related to patient volume, availability of expertise and resource limitations.

2)  Training of anaesthetic, nursing and paediatric staff on APS.
3) Education of patient relatives on pain assessment and management after ambulatory surgery.
4) A 24 hour/day coverage of APS with written self-explanatory guidelines and protocols, with rapid response to paging and phone callings.
5)  Availability of physicians or anaesthetists, algology qualified from centers like National Cancer Institute (NCI) at Cairo, to supervise those models and to deal with specific patients on high tech therapy in the PACU.
6)  Efficient – quality assurance programming should always be in work.

Towards an African Style:
Such a suggested Egyptian organization model may open the door to other African pain authorities with similar difficult equations to introduce their own organization models. Guided by the IASP, the interaction of these models might push to light an African Style for pediatric APS side-by side with the American and European Styles.  So, we recommend intensive communications between African health care and pain authorities to organize a separate APS model for Africa.

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