Fig. 7.1
An 8-year-old (12 kg) female affected by osteogenesis imperfecta
7.1.2 Ambulatory Orthopaedic Surgery in Children
Ambulatory surgery is a somewhat lighter burden for health services, resulting in considerable cost reduction and resource saving. Paediatric orthopaedic surgery seems to be rarely done in an outpatient setting, mainly because of the postoperative pain, which all parents fear. The anaesthetic management is challenging because young children lack the ability to communicate pain, and analgesic need is often difficult to determine. Therefore, provision of adequate postoperative analgesia and parents’ education are important elements of the care plan. Inclusion criteria for ambulatory surgery proposed by Khoury et al. [1] are summarised in Table 7.1. Parents must be adequately informed on how to deal with cast, including possible complications. They should be given written instruction and a staff contact number should be available as well. Of the utmost importance is to provide the family detailed information about postoperative pain management and consequences of regional anaesthesia. For example, if the child undergoes a nerve block, parents should be aware of what is an acceptable time for resumption of active motion. The most frequent orthopaedic ambulatory procedures are cast change, arthroscopy, closed fracture reduction and manipulation, hardware removal, percutaneous tenotomies and arthrograms.
Table 7.1
Inclusion criteria for orthopaedic paediatric ambulatory surgery
Social and geographic factors |
Surgery schedule compatible with day-care unit opening hours |
Parents able to follow pain management and follow-up instructions |
Availability of a phone at home |
Ability to return to hospital in less than 30 min |
Surgical criteria |
Surgery lasting <90 min |
Minimal estimated blood loss or fluid shifts (<10 % of total BV) |
Few operative complications anticipated |
Patient conditions |
Child of >4 months of age if preterm or born at term if ageing <4 months |
ASA physical status classification I or II |
Absence of apnoea syndrome |
7.1.3 Preoperative Fasting and Premedication
Every child has to be treated individually and it is therefore difficult to establish fixed rules regarding the perioperative anaesthetic management. For preoperative fasting, the orthopaedic setting shares the same rules of any other surgical specialty, but in this arena, trauma patients are frequent and the stomach of traumatised children is assumed never to be empty. Nonetheless, it may be necessary to treat the child as fast as possible, mandating for focused attention to advanced airway management. Preoperative anxiety may be reduced by premedication similarly to other surgical settings, but non-pharmacological strategies are available as well. Indeed, there is evidence that the viewing of animated cartoons by paediatric surgical patients is an inexpensive, easy to administer, comprehensive intervention that can be very effective in alleviating preoperative anxiety and “needle phobia” in this special surgical population [2]. Furthermore, it may be useful to apply EMLA tapes not only at the venous puncture site but also at the insertion site of the plexus or nerve block.
7.1.4 Procedural Sedation
Anaesthetic services are commonly required for sedation during diagnostic procedures, non-invasive treatment of fractures and other short but painful procedures. Reposition or manipulation of a fractured limb without sufficient analgesia is inhuman, and, to some extent, it is comparable to severe personal injury. Closed reduction and cast immobilisation in the emergency department are usually eased by deep sedation to reduce procedure-related stress.
Deep sedation for both emergent and elective orthopaedic procedures is associated with several, rare but potentially serious adverse events like apnoea or hypotension, which require continuous monitoring and several dedicated staff members [3]. Furthermore, in these cases, preoperative fasting is mandatory, and postprocedural observation in adequate recovery area may be prolonged with relatively long time to discharge. Performing an analgesic or anaesthetic nerve block (Fig. 7.2) of the interested area based on anatomical considerations results in lighter sedation, reduced risks and shorter postoperative observation time. Indeed, the patients can be discharged 2 h after uncomplicated procedures, even with persistent sensory block. With regard to postoperative pain management, regional anaesthesia combined with postoperative non-opioid analgesics, like paracetamol, NSAIDs, or weak opioid, such as codeine or tramadol, are regularly used after ambulatory surgery.
Fig. 7.2
US-guided infraclavicular nerve block for non-invasive treatment of upper limb fracture
Procedural sedation is also required for non-intrusive approaches for correction of early-onset scoliosis. This treatment in infants and toddlers is based on sequential, repeated body cast positioning, which may initiate as early as at 4 months of age. After the child is positioned on the frame, distraction and derotation of the spine will be performed in general anaesthesia or deep sedation. Plaster application, particularly around the hip, should allow bowel and bladder function, avoid skin breakdown and permit access to epidural or perineural catheters. These infants and toddlers with scoliosis, as well as other children with chronic diseases, present repeatedly for surgical or diagnostic procedures and should be treated with particular sensibility and compassion. Indeed, even a single negative experience can indelibly ruin patient and family attitude toward anaesthesia.
7.1.5 Intraoperative Positioning
Anaesthetists, surgeons and nurses are all responsible for the safe positioning of surgical patients to prevent position-related complications. Paddings, pillows and special jelly frames are required for achieving the best posture on the surgical bed and to protect the patient against damage from inadvertent pressure ischemia. Nerve injuries and skin pressure injuries result from poor positioning, with direct pressure causing ischemia to that area. Spine surgery involving vertebral fusion and instrumentation often requires special operating tables and the patient in a prone position. Special attention must be paid in these cases, because cardiovascular and respiratory functions may be compromised in this position. Body weight should be distributed unburdening the abdomen in order to minimise venous congestion, and direct pressure on the eyeballs must be carefully avoided. The arms should not be abducted or extended greater than 90° from the natural position, and the weight of the arms should be evenly distributed across the forearm to avoid ulnar nerve compression at the elbow. Positioning may be even more challenging in children with important deformities and particular caution is warranted. The use of intraoperative radiologic imaging is common, radioprotective barriers should be used, and radiation exposure must be monitored by the anaesthetist, as well.
7.1.6 Intraoperative Warming
The detrimental effects of hypothermia include increased rates of wound infection, increased blood loss and increased length of stay in recovery room and hospital. Hypothermia exacerbates blood loss by decreasing platelet function, interfering with coagulation factors’ activity and slowing vasoconstriction. Therefore, the monitoring of patient’s core temperature is advisable, and several precautions help maintaining normothermia in the perioperative period. They include active patient warming using forced-air devices, the preservation of a comfortable temperature in the operating room at least until the patient is positioned and covered and an adequate warming of intravenous fluids and blood products before infusion [4]. Furthermore, some diseases, such as osteogenesis imperfecta or arthrogryposis multiplex congenita, may be associated with altered baseline temperature regulation. In these patients, core temperature monitoring is mandatory and special attention must be addressed to its perioperative maintenance (Fig. 7.3).
Fig. 7.3
A 6-year-old male with intraoperative forced-air warming blankets
7.1.7 Tourniquet
Tourniquets are commonly used in surgery to establish and maintain a bloodless surgical field, allowing the surgeon to work with greater technical precision and safety. Nonetheless, the widespread use of tourniquets in orthopaedic surgery in adults and children is not without risks, and the surgical literature includes numerous reports of injuries and hazards associated with tourniquet overpressurization, like pain at the tourniquet cuff site; muscle weakness; compression injuries to blood vessels, nerves, muscles or skin and extremity paralysis. Underpressurization, vice versa, may result in blood leakage in the surgical field and venous congestion of the limb. Overall, the risk of tourniquet-related injuries can be reduced minimising tourniquet inflation time, using automatic tourniquet instruments and cuffs that allow accurate pressure delivery, control and monitoring and maintaining tourniquet cuff pressure near the minimum level required to stop arterial blood flow in the operated limb. Indeed, significantly lower tourniquet cuff pressures based on limb occlusion pressure (LOP) and the use of wide contour cuffs can be used effectively and safely in the paediatric population without compromising the quality of a bloodless surgical field [5]. LOP is the minimal cuff pressure required to occlude arterial blood flow into a patient’s limb with a specific tourniquet cuff at a specific moment. LOP may be determined manually by slowly increasing tourniquet cuff pressure until distal arterial pulsations cease at the Doppler stethoscope or with a recently developed automated plethysmographic system. Previous studies in children showed that tourniquet cuff pressures based on LOP measurements before cuff inflation significantly decreased mean tourniquet cuff pressures and were sufficient to maintain a satisfactory surgical field [6]. Before tourniquet application, a flat rubber bandage named Esmarch’s bandage will be wrapped repeatedly around the limb to make it bloodless, and a soft dressing will be applied to the limb at the tourniquet site to avoid wrinkles and blisters (Table 7.2). Adequate exsanguination can also be achieved by elevation of the limb at 90° or 45° for the upper or the lower extremities, respectively. Also the anaesthetic conduct may influence the effects of tourniquet application. In fact, both the continuous propofol infusion and regional anaesthesia techniques attenuate lipid peroxidation and decrease tourniquet-related injuries in paediatric limb surgery [7]. Also intraoperative temperature regulation may be affected by tourniquet application owing to a combination of decreased heat loss from the ischemic limb and a reduced heat transfer from the central to the ischemic peripheral compartment.
Table 7.2
Recommendations for pneumatic tourniquet use in paediatric limb surgery
1. Use the widest cuff suitable for the selected limb location, and use a contoured cuff able to match the taper of the thigh |
2. Select a limb protection sleeve specifically designed for the selected cuff. If such sleeve is not available, apply two layers of elastic bandage sized such that its basal compression is minor than venous pressure (≈20 mmHg) and less than a snugly applied cuff |
3. Accurately apply the tourniquet cuff over the sleeve, avoiding fluid collection between the cuff or the sleeve and the patient’s skin |
4. Using the applied cuff, measure the LOP and set tourniquet pressure, respectively, 50, 75 or 100 mmHg above LOP for LOP < 130 mmHg, 131 < LOP < 190 mmHg or >190 mmHg. To measure the occlusion pressure, use a plethysmographic tourniquet system or a Doppler stethoscope. For manual measurement, locate an arterial pulse distal to the tourniquet, slowly inflate the cuff until arterial pulse stops for several heartbeats, then deflate and confirm that the pulse resumes. Measurement must be done once systemic blood pressure is stable at the level expected during surgery. Note that the limb should remain horizontal and motionless |
5. Exsanguinate the limb by elevation or elastic bandage |
6. Inflate the tourniquet cuff and monitor the tourniquet during use |
7. If arterial blood flow over the tourniquet cuff is observed, increase cuff pressure in 25 mmHg increments until flow stops |
8. Minimise tourniquet inflation time |
9. Remove the cuff and the sleeve of the tourniquet immediately after the deflation |
7.1.8 Blood Management
Paediatric patients undergoing major orthopaedic surgery are at risk of significant intraoperative blood loss. The judicious use of blood transfusion is imperative both because of limited blood bank supply and because transfusions can lead to various complications. Awareness of infectious hazards of transfusion prompted a more thoughtful approach to blood product administration, greater tolerance of asymptomatic anaemia, more attention to medical, preoperative treatment of anaemia and greater attention to surgical haemostasis. Whenever possible, a cost-effective approach is based on the identification and treatment of preoperative anaemia, and, in most circumstances, it can be accomplished with nothing more than oral iron therapy. Fortunately, the amount of blood transfused for many surgical procedures has decreased in recent years. A close observation (or surveillance) of the operative field helps to estimate blood loss, while the monitoring of vital signs, haematocrit, urine output and central venous pressure is valuable to assess the adequacy of volume replacement and are useful tools in blood-sparing strategies [8, 9].
7.1.8.1 Preoperative Donation of Autologous Blood
As the hazard gap between allogeneic and autologous transfusions narrows (the risk of bacterial infection and mistransfusion are almost the same for the two alternatives), a balanced appraisal of the beneficial and detrimental effects of both is appropriate. Importantly, autologous blood donation (ABD) should not be attempted in children with significant ischaemic cardiac disease or in paediatric patients with an active infection, because bacteria can contaminate the collected unit and overgrow during storage. ABD should be discouraged before procedures for which RBC transfusion is unlikely and in children with needle phobia and limited collaboration capacity. Erythropoietin proved to be useful in a wide variety of patients, including preterm infants, children on chemotherapy, children with renal failure and children undergoing elective major reconstructive surgery, spine surgery, liver transplantation, cardiac surgery and Jehovah’s witnesses. Erythropoietin stimulates erythropoiesis by the bone marrow. Recommended is recombinant erythropoietin, 600 U/kg sc, once or twice weekly, 3–4 weeks before surgery with supplementation of iron, vitamin B12, vitamin E and folic acid oral supplementation. Coordination with the haematology unit, blood bank and the primary patient care team is required to take full advantage of this therapy, especially if ABD is programmed. Common practice is to donate one unit per week, but the last unit should be donated at least 5–7 days prior to surgery to allow plasma proteins to normalise, to restore intravascular volume and to allow adequate erythropoiesis so that the patient will not be anaemic on the day of surgery. Banked units of autologous blood may be stored for 35–42 days in the liquid state. Because of the risk of incorrect patient identification and possible bacterial contamination, also autologous blood has to be transfused only if strictly indicated.
7.1.8.2 Intraoperative Blood Recovery and Reinfusion
Acute normovolaemic haemodilution involves withdrawal of a calculated volume of the patient’s blood after the induction of anaesthesia with simultaneous volume replacement with crystalloid or colloid infusion. The patient’s own fresh blood is carefully stored in a refrigerator and reinfused in the final phase of surgery. The two major advantages of intraoperative haemodilution are the following: blood lost during surgery has a low haematocrit and fresh, whole autologous blood is available for transfusion.
Intraoperative red cell salvage (CS), i.e. the process of collecting shed blood during surgery and reinfusing it to the patients, is often used as an effective blood conservation strategy, and CS has been linked with reduced ABT. The blood recovered from the surgical field will be washed, centrifugated and reinfused. In this way, infectious and immunologic risks of allogeneic transfusion and the risk of mistransfusion will be avoided. Intraoperative blood recovery compared with allogeneic blood transfusion proved cost saving and cost-effective also in paediatric orthopaedic surgery [10]. Nonetheless, this CS is not widely used in paediatric patients, probably because of the capital investment for the devices, the significant costs of disposable parts and the need for a trained operator. CS may be particularly useful to minimise allogeneic blood transfusion in scoliosis surgery, and it may also be used in conjunction with preoperative autologous blood donation, further reducing the need for allogeneic RBC transfusions. The development of paediatric-sized equipment should make this technique more widely used and more cost-effective even in small children. Major contraindications to CS are infection or contamination of the surgical field, sickle cell disease and surgery for malignancies.
7.1.8.3 Antifibrinolytics
The fibrinolytic system is the most important antithrombotic mechanism that maintains vascular patency. Major surgery and trauma cause extensive tissue injury and release large amounts of tissue activators (tissue plasminogen activator, kallikrein and urokinase) leading to a shift from physiological fibrinolysis to hyperfibrinolysis, which decreases clot stability and increases tendency to bleeding, leading to coagulopathy, fibrinogen and clot factor consumption. Antifibrinolytic drugs reduce fibrin degradation through inhibition of plasmin generation, therefore decreasing surgical bleeding and the need for transfusion in adults and children [11]. Tranexamic acid (TXA) is worldwide the most used synthetic antifibrinolytic agent. TXA has a higher and more sustained antifibrinolytic activity in tissue (i.e. ten times stronger) compared to ε-aminocaproic acid, and it is more effective at reducing postoperative and total blood loss in spine surgery. The half-life of TXA is about 80–90 min in patients with normal renal function, and for this reason, a maintenance infusion or repeated administration is generally required to achieve an optimal haemostatic effect. Dosage schemes are not based on pharmacokinetic studies, and there is a large variability in initial loading dose, varying between 2 and 100 mg/kg and a continuous infusion of 3–10 mg/kg/h. Our dosage scheme for paediatric population is 50 mg/kg of intravenous TXA as loading dose (2 g max), followed by an infusion of 5 mg/kg/h.
7.1.8.4 Transfusion Trigger
The “absolute” threshold for red blood cell transfusion is a controversial topic, especially in the paediatric population. Most of the actual recommendations are based on expert opinion or derived from adult studies, and, as observed in adults, the trend in paediatric patients has been toward a lower absolute transfusion trigger. As important as the preoperative preparation of the patient to optimise the Hb level is the awareness that there is no universal trigger for the administration of allogeneic blood products, and clinical decision must be based on the single patient. In the absence of co-morbidities which compromise organ oxygenation or limit the compensatory mechanisms for anaemia, Hb levels as low as 7 g/dL are generally well tolerated and transfusion is recommended if the Hb is lower than 6 g/dL [12].
7.1.9 Postoperative Care
The absence of a family member, the strange environment, hunger, changes in body temperature, the presence of peripheral venous access or a cast are factors that may all contribute to increase the discomfort of the paediatric patient awakening from anaesthesia. A recovery room that permits awaking in the presence of parents and adequate pain control is essential in orthopaedic paediatric surgery. Caring for an alert, calm and cooperative child reduces the workload for nurses in the recovery room because children who are pain-free are less inclined to be uncooperative, and it is less likely that they interfere with the operation site (Fig. 7.4), removing dressings, drainage tubes or urinary catheters [13].
Fig. 7.4
Ilizarov frame in a 9-year-old female affected by Cornelia de Lange syndrome
7.1.9.1 Pain Treatment
Acute perioperative pain in infants and children is still undertreated, although intraoperative and postoperative analgesia significantly improved in the last decades. Intense pain without adequate analgesia will not only cause unacceptable pain at the time of intervention, it will also produce long-lasting pain memory and behavioural disorders [14]. Orthopaedic surgery is one of the most painful and it is frequently described to be more painful than expected. To counteract pain in the immediate postoperative period in infants and children, an adequate multimodal pain therapy concept must be implemented, and local or regional anaesthesia (Fig. 7.5) should be performed whenever possible [15]. Acetaminophen (paracetamol) and NSAIDs are the most common analgesics prescribed for moderate pain in orthopaedics and they should be regularly administered after any painful intervention. Regular, round-the-clock administration of these drugs decreases the need of opioid rescue, and their intravenous administration assures the analgesic effect before the child is able to do oral intake. Opioids should be given immediately and sufficiently whenever necessary, and they may be administered by the intravenous, oral, transmucosal and transdermal route. Long-term pain associated with limb-lengthening techniques, like the Ilizarov frame, or paediatric oncologic orthopaedic surgery, may require oral intake of opioids after hospital discharge. Opioids may also be added to neuraxial anaesthesia through the epidural or spinal route for postoperative pain treatment. Benzodiazepines provide sedative, anxiolytic and amnesic effect; they have no analgesic properties but are synergic with pain medication when muscle spasm is a component of pain.
Fig. 7.5
Continuous sciatic nerve block for pain treatment in septic arthritis of the ankle
Regional anaesthesia in children is an evolving technique with many advantages in perioperative management compared with systemic analgesia. Indeed, the profound analgesia delivered by regional anaesthesia provides ideal psychological conditions for the recovering children and their family, reducing emergence agitation and anxiety often present in the orthopaedic setting. Unfortunately, even for established regional techniques, such as the caudal block, the evidence for procedure-specific indications is not currently well defined [16, 17]. Nowadays, we are able to use regional anaesthesia techniques in more than 80 % of orthopaedic procedures in children. There is significant evidence on a transition from neuraxial to peripheral nerve blocks in clinical practice. The main concern regarding single-shot nerve blocks, even with adjuvant, is the limited duration of analgesia, which is usually sufficient for a large number of orthopaedic procedures, but insufficient in many cases of major surgery. Continuous peripheral nerve blocks (CPNBs) are one of the most recent developments in paediatric regional anaesthesia, and it is a valuable alternative to parenteral opioids or continuous neuraxial blockade for several types of surgery [18, 19].
CPNBs proved superior to traditional opioid-based analgesia in terms of improved analgesia with reduced sedation, nausea, pruritus and length of hospital stay [20]. The multimodal pre-emptive analgesia involves the use of low concentration, motor-sparing blocks in conjunction with other analgesics such as opioids, NSAIDs and acetaminophen. This technique aims to facilitate early ambulation by providing excellent analgesia without accompanying motor weakness. Dadure demonstrated that CPNBs are feasible in the paediatric setting and that in skilled hands they promote prolonged analgesia in the majority of patients without major adverse events. The most common minor adverse events are catheter-related mechanical problems dominated by leakage of local anaesthetic around the catheter and catheter dislodgment [21]. Other minor adverse events are less common in CPNBs compared to continuous epidural infusion.
CPNBs are indicated after major orthopaedic surgery in children, for complex regional pain syndromes, for phantom limb pain prevention and for managing vasospasm. Ropivacaine is the local anaesthetic most commonly administered in CPNBs, and the doses for continuous infusion range from 0.2 to 0.4 mg/kg/h at a concentration of 0.2 %. Specific indications for continuous analgesic treatment include hip, femoral, tibial and humeral osteotomies; traction of femoral shaft fracture; congenital foot or hand malformation; limb elongation; osteosynthesis and exostosis; toe, hand or foot amputation; club foot repair; hallux valgus repair; chronic oncologic pain but also painful physical therapy after knee and ankle arthrolysis or knee ligamentoplasty. Otherwise, painful rehabilitation and physiotherapy are other main indications to catheter positioning, because only if pain is under control, good rehabilitation will be performed [22]. A significant advantage of CPNBs over single injection nerve blocks is the ability to provide prolonged analgesia with relatively low doses of local anaesthetics. Patient-controlled regional anaesthesia is feasible also in paediatric patients, and it was demonstrated that patient-controlled regional anaesthesia with boluses of ropivacaine 0.2 % provides adequate postoperative analgesia with smaller doses of ropivacaine or levobupivacaine and lower total plasma concentrations of local anaesthetics than continuous infusion [23]. Low doses of local anaesthetics remain an important precaution for potential complications such as local anaesthetic systemic toxicity (LAST) and permit the use of these devices even at home after hospital discharge.
7.1.9.2 Compartment Syndrome
Compartment syndrome is a condition in which increased pressure within a closed compartment compromises tissue function and perfusion within that space. It occurs most commonly in an osteofascial compartment of the leg or the forearm, but it may occur in the upper arm, thigh, foot, buttock, hand and abdomen as well. The most common cause of compartment syndrome is a trauma, usually when a fracture occurred [24]. Acute compartment syndrome requires prompt diagnosis and management. Plaster cast immobilisation can cause compartment syndrome and pressure sores. In case of persisting pain, the cast should be removed and the area carefully examined. Delays in treatment can result in significant disability including neurological deficit, muscle necrosis, amputation and death. Severe pain and paraesthesia are often reported as cardinal symptoms, but many authors consider these symptoms unreliable, as they are subjective and variable. These symptoms are particularly difficult to assess at extreme ages or in patients with neurologic compromise, and there is unconvincing evidence that PCA, opioids or RA might delay the diagnosis of compartment syndrome. Main clinical signs are tense, swollen compartments, sensory loss and pulselessness of distal segments. Objective monitoring may be the measurement of compartment pressure by needle or catheter, the monitoring of tissue oxygenation by near-infrared spectroscopy (NIRS) or the dosage of serum creatine phosphokinase (CK) as an indicator of muscle necrosis [25]. High clinical suspicion, ongoing assessment of patients and compartment pressure measurements are essential for early diagnosis. The outcome is related to the time from diagnosis to fasciotomy, which allows tissue decompression and must be performed within 8 h. Delay in diagnosis may be a concern of surgeons when plexus blockade is performed in cases of fractures. It is important to highlight that compartment syndrome is one of the most painful experiences, and it cannot be masked by opioids or other drugs or diluted concentrations of local anaesthetics used for postoperative infusion. Nonetheless, it is nowadays inacceptable that the diagnosis of compartment syndrome is made thank to children’s pain, especially when sufficient diagnostic tools are available [26]. Importantly, surgeries at risk for developing compartment syndrome must be excluded from ambulatory paediatric protocols.