Pre-hospital care Care by paramedics occurs in a very diff erent environment from hospital: resources are limited, backup is unavailable or only available remotely; initial assessmen t and care is oft en initiated in hostile environments, exposed to the elements with limite d vis- ibility; patients can be trapped requiring prolonged extrication; information can be limited and confusing; during transportation assess- ment and procedures may be complicate d by patient movement, crowding, and noise. Basic measures to assist with pain manage- ment include immobilization and splinting of fractured limbs, the dressing of wounds, and cover ing of burns. Burns should be cooled under running tap water for 20 min, even if initial co oling is delayed (Allison and Porter, 2004; ANZBA, 2012) as supported Aims Th is chapter details pain management of children with major trauma covering their ove rall trauma care and the patient journey from pre-hospital, through in-patient care to disc harge highlighting: \227\206 Acute pain management pre-hospital, in the ED and perioperatively. \227\206 Procedural sedation provided in the ward setting. \227\206 Weaning and step-down analgesic regimens. Th is chapter addresses considerations specifi c to burn injuries. Evidence for practices, when available, will be included. Where possible, variations in international practice are presented. SECTION 4 pain in specific populations and diseases 172 by porcine data (Rajan et al., 2009). While decreasing ongoing heat-related tissue damage a nd providing pain relief, cooling of burn wounds in children can cause hypothermia. With la rger burns and younger children, the wound should be cooled and the patient warmed (Allison and Porter, 2004). Temporary burns dressings should be applied in the pre-hospital setting to reduce pain caused by contact and draft and maintain wound sterility while allowing ins pection of the underlying burn. Th ey should not be applied circumferentially as the burnt and periburn tissue can swell with oedema and blistering, causing further pain and vas- cul ar compromise. Such temporary burns dressings include cel- lophane type kitchen wrap and cl ean/sterile sheets (Allison and Porter, 2004; ANZBA, 2012) solution (50 mcg/ml; Borland et al., 2011; Crellin et al., 2010). Th e standard concentrati on solution has advantages of wide availability, lower cost, and potentially less error bec ause it avoids stocking two concentrations of fentanyl. Limited data are available on pre-hospital use of other opioids such as diamorphine, nalbup hine, and tramadol (Hyland-McGuire and Guly, 1998; Mackenzie, 2000; Roberts et al., 2003; V ergnion et al., 2001; Ward et al., 1997; Woollard et al., 2004). Successful pre- hospital u se of femoral nerve blocks has also been reported (Barker et al., 2008; Lopez et al., 2003; Park et al., 2010). Data in children for these agents and techniques are scant. Methoxyfl urane is an inhaled volatile fl uorinated hydrocarbon anesthetic agent available in a portable, compact delivery system. In Australia and some other countries, it is admini stered as an analgesic by paramedics from a plastic tube inhaler. Th e dose lasts approxima tely 30 min. Th e total weekly dose must not exceed 15 ml because of the risk of cumulative dose-related irreversible nephro- toxicity (Medical Developments International, n.d.). Th ere is limited high-level data on pre-hospital pain care for traumatic injuries in child ren. In adults and children with obvi- ous traumatic injury, pre-hospital analgesic adminis tration occurs in a low percentage of patients (Rogovik and Goldman, 2007; Swor et al., 200 5). Th e level of pain care provided in pre- hospital systems is largely determined by the type of staff , their level of training and competency, and the protocols guiding pre- hosp ital analgesic use. Protocols permit the early administration of analgesics by paramedical staff without requiring permission from a remote medical control physician. Earlier increas ed use of morphine (Pointer and Harlan, 2005; Porter, 2004) occurred when pre-hospital prot ocols were modified to improve analgesic care. Case series indicate that it is an effi cacious analgesic in children and adults (Bendall e t al., 2011; Grindlay and Babl, 2009). In addi- tion to nephrotoxity, it has been implicate d rarely in hepatotoxicity (Joshi and Conn, 1974). Th e previous manufacturer, Abbot, with- drew it from the US market in 2001, and the US Food and Drug Administration (FDA) has sinc e removed it from the drug register because of the safety concerns (FDA, 2005). Th e mechanism of methoxyfl urane \200\231s nephrotoxicity is unknown. Methoxyfl urane is c ontraindicated in renal impairment, diabetes, concurrent use of enzyme-inducing drugs or te tracycline, a his- tory of liver damage secondary to anesthesia, malignant hyper- thermia o r hypersensitivity to fl uorinated anesthetics (Medical Developments International, n.d.). Morphine and fentanyl are extensively used in the pre-hospital setting including in air-tra nsported pediatric trauma patients (DeVellis et al., 1998; Krauss et al., 2011). Th ere may be advantages of fentanyl over morphine (see Sethna et al., Chapter 46, this vol- ume). In a systematic review of pre-hospital adult analgesia with intravenous (IV) morphine and IV fentanyl (Park et al., 2010), no patients required ventilatory support and only one patient in each group required naloxone. More recently intranasal fentanyl (INF) has been used in pre-hospital systems and in EDs. INF has similar analgesic effi cacy and time to onset comp ared to IV morphine. A recent review (Hansen et al., 2012) summarizes pediatric INF use as investigated in a number of randomized controlled trials (RCTs). Comparison of INF with est ablished analgesic agents showed simi- lar decreases in pain scores. No major adverse event s occurred with pediatric analgesic INF use and Glasgow coma scale (GCS) and vital signs we re unaff ected (Hansen et al., 2012). Minor adverse events include nausea, vomiting, prurit is, drowsiness, and a bad taste in the mouth. INF as a sole agent has a low incidence of em e- sis. Th e hazards to staff of IV or intramuscular (IM) administra- tion in a moving vehi cle combined with diffi culties of establishing IV access in children makes INF attractive (Bendall et al., 2011; Johnston et al., 2011). INF is administered by either a mucosal atom izer device (MAD ; attached to a syringe for metered dosing) or a drop-by-drop technique. Usual dosing is 1.5 mcg/kg, divided between each nostril. Th is administration route bypass es gastroin- testinal and hepatic elimination (Hansen et al., 2012; Panagiotou and Mystakid ou, 2010). A maximum volume limit of 0.15 ml was suggested to avoid pharyngeal run off (Dal e et al., 2002; Hansen et al., 2012). In past studies high concentrations of usually 100 mc g/ ml to 300 mcg/ml have been used (Borland et al., 2007; Hansen et al., 2012). However, tw o recent pediatric studies have dem- onstrated similar analgesic effi cacy of INF using the standard IV Nitrous oxide (N 2 O) use on ambulances was described fi rst in 1970 (Baskett, 1970). Recen t reports indicate its continuing avail- ability on ambulances in many pre-hospital systems (Bledsoe et al., 2005; Roberts et al., 2003; Siriwardena et al., 2010). It is usually admi nistered in fi xed concentration (50% N 2 O and 50% oxygen) with a demand valve that limits its utility to children over 4 years of age, who can generate adequate negative pressure t o open the valve. It is also problematic in cold environments (Borland et al., 2002). Traum a patients who have potential air trapping (e.g. suspected pneumothorax) may not receive N 2 O. Ketamine has also been used as an analgesic in the pre-hospital setting (Bredmose et al., 2 009; Galinski et al., 2007; Jennings et al., 2012; Reid et al., 2011; Svenson and Abernathy , 2007). Th is includes use in pediatric trauma patients in parenteral and intranasal form (Bredmose et al., 2009; Reid et al., 2011; Svenson and Abernathy, 2007). In a physician-led air ambulance service, 164 children received IV or IM ketamine for analgesia for burns or for proce- dural sedation for fracture reduction (Bredmose et al., 2009). Th ere were no ad verse events or loss of airway, consistent with large scale ED data (Green et al., 2009a, 2 009b). In an RCT of 135 adult trauma patients, IV morphine plus low-dose ketamine administe red pre- hospital for moderate to severe pain provided superior analgesia to IV morphine al one but was associated with an increase in minor adverse events (Jennings et al., 2012). Pre-hospital use of non-pharmacological techniques has also been described, including RCTs of acupressure in adults (Kober et al., 2002; Lang et al., 2007; McManus and Sallee, 2005). CHAPTER 18 pain management in major pediatric trauma and burns 173 Emergency department care of trauma De \201 nitions and classi \201 cation of trauma Trau ma severity can be classifi ed by injury extent, type, and severity. Injury extent centers around the number of body systems involved with multitrauma defi ned as involvement of two or more body areas. Injury type refers to penetrating versus blunt trauma. Injury severity groups trauma based on injury mechanism (such as a fall from a cer- tain height) with fi nd ings during physical examination. High-risk trauma mechanisms have increased risk of clinic al deterioration and require higher level care. A number of diff erent pediatric trauma cla ssifi cation systems assist with patient triage, assess the severity of illness, and predic t mortality (Marcin and Pollack, 2002). of Surgeons \200\231 Advanced Trauma Life Support (ATLS ) Course (American College of Surg eons, 2008). ATLS focuses on the rec- ognition and management of life-threatening abnorma lities of vital functions (primary survey and resuscitation) followed by a com- prehensive systematic assessment of the trauma patient (secondary survey). IV access is achieved to manage circulatory status, and is then available for IV analgesia. Parenteral opioids are the gold standard for analgesic management worldwide in the setting of moderate to severe trauma and burns management. If IV access is delayed in an unstable pediatric trauma patient, intraosseous access can be quickly established and permits fl uid and drug administra- tion including all analgesics (Von Hoff et al., 2008). If patients do not require IV access, such as in mild or isolated extremity trauma, INF provides an excel lent alternative (Borland et al., 2007; Hansen et al., 2012) and its use can in itself redu ce the need for IV access by 50% (Borland et al., 2008). Analgesic dosing is listed in Tabl e 18.1 . Overall trauma management Pain management in children with major traumatic injuries should be embedded in a standardized approach to trauma care such as the globaly used and taught s ystem of the American College Table 18.1 Analgesic doses used in for pre-hospital or emergency department setting Analgesic categories and agents Formulation Initial or loading dose Subsequent dosing Maximum dose Notes Parenteral opioid IV morphine 10 mg/1ml 50 \200\223100 mcg/kg 10 \200\22350 mcg/kg No ceiling but if 200 mcg/kg used consider adjuvant therapy Gold standard; histamine release may cause hypotension IV meperidine 100 mg/ml \200\223 \200\223 Due to abuse and neurotoxic metabolite rarely used now IV oxycodone 10 mg/1 ml 100 \200\223200 mcg/kg 25 \200\22350 mcg/kg IV formulation recently available IV hydromorphone 2 mg/ml 10 \200\22320 mcg/kg 2 \200\22310 mcg/kg IV fentanyl 100 mcg/2 ml 1 \200\2232 mcg/kg 0.25 \200\2230.5 mcg/kg Shorter onset and shorter acting; bradycardia can occur (with hypotension) Intranasal fentanyl 100 mcg/2 ml Or 300 mcg/2 ml 1.5 mcg/kg (50% in each nostril) 3 mcg/kg Onset within 10 min with duration of c .60 min IV remifentanil 1 mg, 2 mg ampoules 0.2 \200\2230.5 mcg/kg Infusion 0.1 \200\2230.2 mcg/kg/min Very potent; rapid onset and o \200 set within 1 \200\2233 min; risk of respiratory depres sion/apnoea very high and so not used in pre-hospital setting 5HT/NA/opioid e \200 ects Tramadol IV Capsule/tablet Elixir 1 \200\2233 mg/kg 1 \200\2232 mg/kg 6/24 100mg/dose 400mg/day Lowers seizure threshold; avoid if serious head injury. Similar sedation, nausea and vomiti ng rates to opioids. M1 metabolite active at mu opioid receptors. 100 mg/2 ml 50 mg IR 10 mg/ml Non-opioid Acetaminophen IV 500 mg/50 ml or 1000 mg/100 ml Typically 500 mg tablet And various mg/ ml concentrations av ailable 15 mg/kg if IV Some use loading doses of 20 \200\22330 mg/kg orally 15 mg/kg 4 \200\2236/24 1 g/dose 60 mg/kg/day Some institutions use loading doses; no load and 6/24 prescribing introduced for uniformity across authors \200\231 institution Cost of IV 60 \200\223180x that of syrup-tablet dose oral tablet Syrup (Continued) SECTION 4 pain in specific populations and diseases 174 Table 18.1 (Continued) Analgesic categories and agents Formulation Initial or loading dose Subsequent dosing Maximum dose Notes IV acetaminophen Neonates 10 mg/kg 10 mg/kg 6 \200\22312/24 Maximum depends on postmenstrual age (Palmer et al., 2008) NSAIDs Ibuprofen IV And oral Tablet, caplet Syrup 5 \200\22310 mg/kg 10 mg/kg tds Give with meals if tolerating oral intake Generally avoided in acute resuscitation phase as impair platelet adhesion (increasing blee ding risk) and glomerular \201 ltration rate reversibly by 20% (Anderson, Chapter 43, thi s volume) and can precipitate renal failure in low output states 100 mg/1 ml 200 mg 100 and 200 mg/5 ml Diclofenac IV and rectal 1 \200\2232 mg/kg 1 \200\2231.5 mg/kg 8 \200\22312/24 50 \200\223100 mg/dose Suggested ceiling e \200 ect; higher doses prescribed in practice 25 \200\223100 mg suppositories 12 \200\223100 mg Tablet Indomethacin IV PO 100mg/dose IV Ketorolac 60 mg/ml US 1 mg/kg 0.5 mg/kg 6/24 Maximum 60 mg load then 30 mg per dose Maximum 10 mg/ dose Not licensed for use in children <12years Costly 10 mg/ml Australia and New Zealand no load 0.2 mg/kg 6/24 COX-2 inhibitors Rofecoxib oral 50 mg tablet 1 mg/kg 50 mg/day Was licensed for use in acute pain. Withdrawn by FDA post cardiac events Celecoxib Capsule 100 mg and 200 mg Suspension (not marketed; Donnelly et al., 2009) \200\223 2 \200\2234 mg/kg 12/24 400 mg/day Not licensed for use in acute pain; can disperse capsule contents in water IV Parecoxib 40 mg powder 1 mg/kg daily 40 mg/day NMDA antagonist IV Ketamine 200 mg/2 ml Analgesia: 0.5 mg/kg Anesthesia: 1 \200\2232 mg/kg 0.1 \200\2230.4 mg/kg boluses or infusion per hour If infusion used, usual dose 0.2 mg/kg/h with maximum 0.4 mg/kg/h Used in children older than 2 years as adjunct or sole agent Benzodiazepines Midazolam 5 mg/ml OR 5 mg/5 ml 0.05 \200\2230.1 mg/kg IV 0.5 mg/kg PO 0.4 mg/kg rectal/nasal Amnestic and muscle relaxant to treat spasm or assist reenlocation Diazepam IV Tablet Syrup 0.025 \200\2230.05 mg/kg IV 0.05 \200\2230.1 mg/kg PO/PR To treat muscle spasm as an adjunct to opioids and regional, e.g. femoral nerve block 10 mg/1 ml IV 1 mg/ml PO 5mg Suppositories Inhalational Nitrous oxide Entonox premix 50% adjustable system that delivers up to 70% 50 \200\22370% delivery for analgesia Can cause nausea and vomiting; at higher concentrations can cause sedation. Avoid in closed pneumothorax, bowel obstruction Methoxy \202 urane Penthrox whistle 0.1 \200\2230.3 MAC analgesic c = circa; FDA = Food and Drug Administration (US authority); IR = immediate release; IV = intravenous;NA = noradrenaline; NSAIDs = non-steroidal anti-in \202 ammatory drugs; MAC = minimum alveolar concentration; NMDA = N-methyl D-aspartate; PO = oral; = register ed trade mark; 5HT = serotonin CHAPTER 18 pain management in major pediatric trauma and burns 175 Burns assessment and management Th e majority of pediatric burns are hot liquid scalds. Con tact and fl ame burns are less frequent but cause deeper injury. Inhalation airway and lung burns are particularly problematic and in fi res can be associated with carbon monoxide po isoning. right leg was very tender. She had a femoral nerve block placed by the emergency physician under ultrasound guidance. She ceased complaints of leg pain and was log rolled to assess h er back. Due to ongoing clavicle, chest, and abdominal pain of 5/10, she was given two furt her boluses of IV fentanyl followed by IV ketamine (5 mg = 0.1 mg/kg) which settled her pai n. However, she became less responsive with a GCS score of 10. It was unclear if the decrea se in consciousness was due to her alcohol ingestion, the opioid and ketamine used, or a co ncomitant head injury. An urgent computed tomography (CT) scan of the head showed bilateral cerebral con- tusions without midline shift , an abdominal CT showed a small liver lacerat ion. On return from the CT scan her GCS score was 8 and she was intubated for airway protec tion by rapid sequence induction using thiopental and succinylcholine. Th e majority of pediatric burn patients can be managed in EDs alone (Rawlins et al., 2007) . Criteria for admission and transfer to specialized burn centers have been published (ANZB A, 2004). Dressings for superfi cial and partial thickness burns have been Cochrane reviewed (Wasiak et al., 2008). Twenty-six RCTs were assessed and most were methodologically poor. Th e use of biosyn- thetic dressings is associated with a decrease in time to healing and reduction in pain during dressing changes. Th e use of the traditional silver sulphadiazine as compar ator in some studies was considered problematic as it was associated with delay in wound he aling and increased number of dressing changes. Th e existing evidence is of lim- ited usef ulness in aiding clinicians in choosing an optimal dressing. Case example: burns (continued) Th e 2-year-old boy with scald burns was assessed to have 30-degree scald burns with large blisters developing over chest and upper abdomen. His burns were covered with a clean sheet by the paramedic services. He was screaming in pain. Paramedics administer INF at 1.5 mcg/ kg. On arrival at the hospital, he had stopped crying. In the ED he was assessed to have no airway involvement and no circumferential burns were found. He had an IV placed and receiv ed hydration and IV morphine 0.1mg/kg. He was assessed by the burns team and his burns were covered with a silver containing dressing. Due to his burns \200\231 extent, he was admitt ed to a burns unit. Pain assessment Pain assessment in the ED is often difficult, complicated by the urgency of critical medical issues with competing priori- ties, language barriers, patients affected by drugs or alcohol, and the difficulty of assessing patients with an immobilizing neck col lar receiving oxygen or who are intubated, sedated, or medicated with muscle relaxants. In younger children, it is difficult to distinguish pain and distress. An inebriated, drug aff ected, or head-injured child or adolescent may be combative or uncooperative. Pain is assessed using tools appropriate for the child \200\231s develop- mental stage, num eracy and literacy level, and intellectual capa- bility (see chapters in Section 5 of this volume). Abnormal vital signs are sometimes used as proxies for pain, but in the trauma set ting may refl ect hypovolaemia and can be unreliable even in healthy subjects (Tousignant-L afl amme et al., 2005). Th e Critical Care Pain Observation Tool (CCPOT) has been developed to assess pain in critically ill ventilated adults. It has good inter-rater reliability (G elinas and Johnston, 2007) with behavioral indica- tors providing more valid pain informati on than physiological indicators. Emergency department analgesia options Opioids \200\224if the patient is still in pain, bu t is ventilating adequately and does not have a depressed conscious state, further IV opioi ds may be titrated (see Table 18.1 for dosing): if pain is mild, at 20% to 50% of loading d oses; if pain is severe, repeat loading is appropri- ate, depending on the timing of the la st opioid dose pre-hospital. If two loading doses have been given within the expected durat ion of the opioid \200\231s eff ect and pain is still severe, then adjunctive agents can be administered while reassessing the child. Compartment syndrome must be considered in the s etting of limb fractures and circumferential burns when opioid requirements escalate or pai n is uncontrolled. Monitoring and early referral for pressure testing, compartment release, or escharotomy is essential. Case example: trauma (continued) Aft er placing a neck collar and providing oxygen by mask, the 14-year-old train-surfer was assessed for pain. A patient-reported pain scale could not be obtained due to poor coopera tion. A par- amedic assigned her a numerical pain scale of value 10/10. While on the train tracks she was off ered methoxyfl urane and coached in using it, decreasing the paramedic a ssessed pain score to 4/10. She had an IV placed and received fl uid resuscitation. Her rig ht leg was splinted. During the transportation to the trauma center, she received IV morphi ne (5 mg) due to ongoing pain. She was esti- mated to weigh 50 kg. On ED arrival, she was a ssessed by the trauma team. On her secondary survey she was found to have a left clavicle f racture, multiple left rib fractures with pulmonary contusion, abdominal tenderness, and a right mid-shaft femur fracture. She was treated with oxygen by face mask and a second fl ui d bolus for hypotension. Her pain was assessed as 7/10. Her Tramadol (see Rastogi and Campbell, Chapter 48, this volume) is an alternative to opioids, also available in parenteral and oral forms. It is not licensed for use under 12 years of a ge and has not been studied in pediatric trauma or burns patients. Non-opioid analgesics are used to spare opioid use, reducing opi- oid-related side eff ects. Acetaminophen (paracetamol) is an eff ective analgesic (Anderson, Chapter 43, this volume). As it is available in IV form, it is a use- ful intervention in the acute trauma and burns setting (Babl et al., 2011) as patients are fasting and plasma levels are rapidly achieved (over the rectal or oral route). Patients admitted with trauma or burns typically receive acetaminophen for several days to weeks. Th eir liver function should be monitored and the daily maximum prescribed should take expected duration and probably ideal body weight into account. SECTION 4 pain in specific populations and diseases 176 Non-steroidal/non-selective anti-infl ammatory drugs (NSAIDs; Anderson, Chapter 43, this vo lume) are not used in the acute mod- erate to severe trauma and burns setting due to their platelet inhib- iting and renal eff ects. Platelet inhibition (although reversible with all except aspirin) may exacerbate bleeding propensity, particularly if coagulopathy is presen t. NSAIDs reduce renal arteriolar fl ow and reversibly reduce glomerular fi ltration, via c yclo-oxygenase (COX)-2 inhibition. If the patient is volume deplete, from blood or extracel lular fl uid loss (due to trauma and burns respectively), this NSAID eff ect may precipitat e renal failure (Musu et al., 2011). 2008a; Kanagasundaram et al., 2001). N 2 O up to 70% for proce- dural sedation and analgesi a is usually well tolerated by children with a low incidence of minor adverse events (5 \200\2238%: including vomiting, nausea, dizziness, and light-headedness) and rare seri- ous or potentially serious adverse events (Babl et al., 2008b; Zier and Liu, 2011). Apnoea, as piration, or the need for airway interven- tion has not been reported in large series aft e r single-agent use of N 2 O. In trauma patients N 2 O should be avoided in patients with ch est trauma and the possibility of an expanding pneumothorax or in head injured patients whe re there is a possibility of expanding intracranial air. Th e N-methyl-D-aspartate (NMDA) antagonist ketamine (Cravero, Chapter 20, this volume) is used in the major trauma/burns ED set- ting usually as a second- or third-line agent to IV opioids and IV acetaminophen when pain is still problematic. It is generally given as inter mittent boluses of analgesic doses of 0.1 to 0.2 mg/kg every 10 min (i.e. 10% of an anesthe tic dose). Morphine sparing effi cacy of 0.2 mg/kg IV over placebo was found in adult traum a patients (n = 65; Galinski et al., 2007). Ketamine is not a respiratory depres- sant in i ts own right; however, it should be carefully titrated using a maximum single bolus of 0.5 mg/kg as opioid-induced respiratory depression can be precipitated once analgesia is achiev ed. N 2 O may also have adverse eff ects on staff or parents. Although there is no conclusive e vidence for reproductive, genetic, haema- tological, genetic, or fetal eff ects (Axelsson e t al., 1996; Rowland et al., 1992; Sanders et al., 2008), exposure should be minimized: usi ng occupational health and safety approved sedation rooms, maintaining an adequate patient face-to-mask seal and using a suit- able scavenging system. Exposure to N 2 O should be avo ided during pregnancy. Ward management Patient-controlled analgesia (PCA) delivery of opioids for alert, extubated patients over 7 years (McDonald and Cooper, 2001; Playfor et al., 2006) and nurse-controll ed analgesia (NCA) (also described as continuous opioid infusions with nurse-initiated bolu ses) for younger patients, infants, and intubated patients (see Howard, Chapter 27, this vo lume) are universally used in the set- ting of major trauma/burns. Th ese may be initiated in the ED and the patient continues to use this during their ward stay. Benzodiazepines (BDZs), such as midazolam, diazepam, lorazepam, may be used in these patien ts \200\231 acute management for their muscle relaxant, anxiolytic, and sedative properties . Th ey are used to supplement parenteral opioids or a regional block (e.g. frac- tured fem ur) to alleviate muscle spasm. Th ey are used if the patient has escalating anxiety and/or distress (Kennedy, Chapter 34, this vol- ume) not responding to analgesia and opioid titrat ion. Midazolam has the additional benefi t of antegrade amnesia and rapid onset (see Table 18.1). Th e most common opioid used is morphine but any opioid can be prescribed (Table 19.1). Th e usual prescription is for 1 to 2 ml boluses with a lockout of 5 to 7 min. Some institutio ns include a 1 or 4 h limit. In acute postoperative pain management, a background infusion on a PCA is generally avoided beyond 24 h (Howard, Chapter 27, this volume). In a trauma or a burn patient, a background is more oft en prescribed; when the continuous rate is higher than 2 ml/h, the bolus size is usually increased to match. An NCA involves the same concen tration dilution infused at 0.5 \200\2234 ml/h with 1 \200\2232 ml boluses usually every 5 to 10 min. Single-shot nerve blocks in trauma in the ED are useful (Barnett, 2009). Th eir application in trained hands is easily achieved, reducing or avoiding the need in multitrauma patients for opioids. In major trauma, a frequently used and useful block is the femoral nerve bloc k . Pediatric femur fractures generally occur in the mid-shaft which is supplied by the fem oral nerve (Barnett, 2009). Bupivacaine is usually used because of its longer duration of a ction. Following pediatric anaesthesiologists \200\231 practice (Flack and Anderson, 2012; Tsui and Suresh, 2010), the availability of ultrasound machines in EDs allows confi rmation of the target nerve \200\231s position and avoids unwanted puncture and intravascular or i ntraneural injection (Frenkel et al., 2012; Reid et al., 2009). Th e alternative to a femo- ral nerve block is the fascia iliaca compartment block which has been successfully used in children in the ED. Th is block (performed without ultrasound; using ropivacaine) was comp ared to IV mor- phine for pediatric femoral fractures. It provided clinically supe- rior pa in management from 0.5 to 6 h (Wathen et al., 2007). Adjunctive continuous ketamine infusion (Howard, Chapter 27, this volume) is used frequentl y in these patients. Typical pediatric infusion prescriptions include ketamine 5 mg/kg in a total of 50 ml normal saline run at 0.1 to 0.3 mg/kg/h (1 \200\2233 ml per hour) (<http:// www.rch.org.au/anaes/pain_management/Ketamine_Infusion/>). Higher infusion rates may be em ployed but hallucinations may occur (contributed to by polypharmacy, sepsis, and sleep depr iva- tion). Our institution has infusion guidelines permitting additional ketamine bolus ad ministration of 0.1 to 0.2 mg/kg every 30 min to be co-administered with opioid boluses or as an alternative if opioid side eff ects are prominent. N 2 O can be used where short-acting sedation and analgesia is required for procedures asso ciated with pain, discomfort or anxiety (see Cravero, Chapter 20, this volume). It can be u sed for minor trauma, instrumentation, and vascular access (Krauss and Green, 2006; Mace et al., 2008). N 2 O should be combined with analge- sia and topical, local, regional, or IV regional anesthesia when- ever possible to enhance the relatively weak analgesic properties of the agent for trauma-related procedures (Babl et al., 2008a). To achieve analgesia for painful procedures, N 2 O can be com- bined with other techniques, such as INF (Seith et al ., 2012), oral analgesia, and a haematoma block (Luhmann et al., 2006) or IV regional anest hesia (Bier \200\231s block). N 2 O reduces recall (Babl et al., NSAIDs are particularly eff ective for pain of bony and muscular origin and may be used in the acute phase of analgesic manage- ment of musculoskeletal trauma and limb fractures, onc e volume resuscitation is complete, haemodynamic stability is achieved, and urine output is established (Anderson, Chapter 43, this volume). Parenteral forms are available. If NSAIDs are used when the patient is fasting or has an ileus, co-administration of a proton pump i nhibitor is routine in moderate to severe burns or trauma patients CHAPTER 18 pain management in major pediatric trauma and burns 177 to reduce the combined eff ects of stress and NSAIDs on the gastric mucosa. NSAIDs also imp air osteoclast activity. Th is is desirable to reduce heterotropic bone formation but undes irable in the setting of extensive bone graft /fusion procedures. Reduced fusion has been r eported in adult studies using high-dose ketorolac but not with normal-dose short-duration exposure (Li et al., 2011) and not in a retrospective review of teenagers (Sucato et al., 2 008). One Canadian article reports ketamine use for 37 days in a child (White and Karsli, 2007). Th ere is no consensus on the indications for muscle paralysis (Playfor et al., 2007). Musc le relaxant administration is generally reserved for trauma-burn patients with head injury, facial \200\223airway \200\223 pulmonary burns, smoke inhalation and primary or secondary res- piratory disease, dyssynchrony with the ventilator, or use of the less physiological v entilation techniques such as high-frequency oscil- lation. Higher-dose analgesic administr ation has resulted with the move away from prolonged muscle relaxant administration during prolonged ventilation (Playfor et al., 2007; Twite et al., 2004). Th e patients frequently develop polytolerance (Playfor et al., 2006). As a result, achieving adequate sedation leve ls can be challenging and the patient may resist mechanical ventilation and require physica l restraint despite receiving high doses of multiple agents. Delirium and emergence phenome na are experienced and complicate the clinical assessment of pain, distress, and septic epi sodes (Playfor et al., 2006). Th ese patients commonly receive supplementation with alterna - tive sedative agents (Playfor et al., 2006; Tobias, 2005; Twite et al., 2004) including a ntihistamines, chloral hydrate (25 \200\223100 mg/kg, 4 \200\2236/24), psychoactive agents (haloperidol, chlorpromazine, and more recently olanzapine (Stoddard et al., 2006)), propof ol infu- sions 1 to 3 mg/kg/h for limited periods (with the clinicians being aware of propo fol infusion syndrome) and alpha-2 agonists cloni- dine (transdermal, intermittent IV bolus doses 2 \200\2235 mcg/kg three times daily or infusion 0.1 \200\2232 mcg/kg/h) and more re cently dexme- detomidine by IV/subcutaneous (SC) infusion at (0.1 \200\2232 mcg/kg/h with o r without loading dose of 0.5 \200\2231 mcg/kg) (Lin et al., 2011; Phan and Nahata, 2008; T obias, 2007, 2008; Walker et al., 2006). ICU staff may involve an acute pain service early or prior to dis- charge to the standard ward. Th e newer COX-2 inhibiting agents (Anderson, Chapter 43, this volume) available are IV par ecoxib (a prodrug of valdecoxib) and oral valdecoxib in its own right. Oral celecoxib is in capsule form which may be challenging to administer to children. A suspension is stable (D onnelly et al., 2009) but has not been marketed. Th ese agents are used off license in chil dren during or post surgery where bleeding is a concern and reduction or avoidance of opioi d use is desirable, e.g. in patients with respiratory or neurological compro- mise or obstr uctive sleep apnoea. COX-2s are without the platelet inhibition eff ect but still share the NSAIDs \200\231 renal eff ects and are thus used post-stabilization in acute trauma and bu rns. Th ey are employed in skin graft surgery, to reduce opioid requirement par- ticularly when pruritis with burns is prominent, or for bone graft - ing surgery when the clinicians wish to avoid NSAIDs. Regional analgesia Single-shot blocks performed in the ED can be repeated aft er ward admis sion and are employed perioperatively for these patients. Anaesthesiologists can off er cat heter techniques and local anaes- thetic infusions (see Zempsky, Chapter 47, this volume) ( usually performed while anesthetized) for internal fi xation and limb reim- plantation proc edures of the upper (brachial plexus and interscalene techniques) and lower limbs (femoral and fascia iliaca), fractured ribs, fl ail segments, and thoracotomy (intercostal nerve blo cks and paravertebral block/catheter) or for thoracic or abdominal surgery or lower limb fr acture or graft surgery (epidural or caudal catheter/ single shot). Other perioperative sin gle shot nerve blocks employed are for free fl aps and skin harvesting and/or graft ing. Th ese include lateral cutaneous nerve of thigh and transversus abdominis plane blocks and th e aforementioned brachial plexus, femoral and fascia iliaca blocks (Sethna et al., Chapter 46, this volume). Alpha-2 agonists Th ese agents have multiple desirable properties for use in burn or multit rauma patient management (Phan and Nahata, 2008). Th ey are sedative, anxiolytic, reduce pa tient and distress, sympathetic outfl ow, and are adjunctive analgesics (Playfor et al., 20 06). Th ey are eff ective by reducing release of presynaptic catecholamines. Th e mechanism of analgesic eff ect is unclear with central (locus coeru- leus) versus spinal (descending inhibition) versus peripheral eff ects (via substance P) proposed. ICU analgesia-sedation practices Th ese patients are typically on opioids for prolonged per iods. Th e commonly administered agents in ICU for analgesia and seda- tion management are the opioids morphine and fentanyl and the benzodiazepines midazolam and lorazepam (Playfor et al., 2006; Stoddard et al., 2011b; Tobias, 2005; Twite et al., 2004). A consen- sus guid eline has been created in the UK for critically ill children (Playfor et al., 2006). It sug gests: Clonidine causes a degree of bradycardia and hypotension which may be desirable in the poly tolerant agitated patient but can be problematic during septic episodes. Interestingly in t hermally injured rat studies, clonidine \200\231s vasoconstrictive eff ects were sug- geste d to be detrimental by impairing healing (Cassuto et al., 2005b) and benefi cial in terms o f oedema reduction (Cassuto et al., 2005a). Th e bradycardic, hypotensive side eff ect also occurs with dexme- detomidine. Reports state it is well tolerated during sedation of the c ritically ill patient including pediatric cardiac or respiratory ICU patients (off -label u se; Phan and Nahata, 2008; Tobias, 2007). \227\206 Morphine infusions of 10 to 60 mcg/kg/h. \227\206 Fentanyl infusions of 4 to 10 mcg/kg/h. \227\206 Midazolam 2 to 10 mcg/kg/min. Th e doses for sedation are outlined in the \200\230ICU analgesia-sedation practices \200 \231 section. Alpha-2 agonists are also useful premedicants prior to second-phase trauma or burns surgery: single-dose cloni- dine 2 to 5 mcg/kg orally or IV alone or combined with m idazolam 0.5 mcg/kg oral or 0.1 mg/kg IV. Dexmedetomidine 2 mcg/kg has been used via the in tranasal route and compared favorably to oral midazolam 0.5 mg/kg, as premedication prior t o burns reconstruc- tive surgery (Talon et al., 2009). Ketamine is not mentioned in the 2006 UK consensus. It is used in Australian and US ICUs (T wite et al., 2004). In our experience this patient group requires high infusion rates, e.g. greater than 5 to 7 mcg/kg/min or 300 to 400 mcg/kg/h, while a US review reports the use a s sole agent at high sedative doses of 1 to 2 mg/kg/h (Tobias, 2005). We typically co-admin ister ketamine, opioid, and benzodi- azepine infusions in these patients when in ICU for da ys to weeks. SECTION 4 pain in specific populations and diseases 178 physical therapy. Th e long-acting component is weaned when the patient requires less than two rescues a day. Th e drop in dose is usu- ally \200\230convenient \200\231 according to the available tablet size. Usually the morning dose is reduced fi rst as the patient can r equest rescue medi- cation while awake during the day. Th e night dose is maintained to fac ilitate comfort in sleep and weaned and ceased last. Case example: trauma (continued) Th e 14-year-old train-surfer went to the operating room to have an intracranial pressure m onitor placed and the right femoral fracture repaired with an internal fi xation device. In the ICU she was sedated using morphine and midazolam infusions. Aft er 24 h, sedation was stopped and she was extubated. She was neu- rologically normal but complained of severe lef t chest pain (rib fractures) and right thigh pain which was inadequately controlled with in termittent boluses of IV morphine. She was started on a PCA device with IV morphine and req uired this for 5 days. Her daily IV morphine consumption was 80 mg, 95 mg, 60 mg, 50 mg, an d 40 mg respectively and so on day 6 she was converted to oxycodone CR and IR. She was stil l complaining of rib pain and disturbed sleep. She was prescribed OxyContin 20 mg morning and 30mg at night and intermittent oxycodone IR 5 to 10 mg with amitriptyline 25 mg at nig ht. She was discharged home on day 10 on OxyContin 10 mg twice daily, oxycodone, ibuprofe n, and amitriptyline 50 mg at night for review by her gen- eral practitioner.