Paediatric emergencies

Authors


R. J. McDougall
Email: Rob.Mcdougall@rch.org.au

Summary

The care of sick children can be challenging for the anaesthetist who is only involved in the occasional care of paediatric patients. This paper outlines the care of medical and surgical paediatric emergencies for which an anaesthetist working at a district general hospital or equivalent may encounter. Conditions discussed include paediatric respiratory emergencies, sepsis, status epilepticus, the acute abdomen in the newborn, intussusception, the bleeding tonsil, trauma and the child with burns.

In 2006, the UK Department of Health (DoH) published The acutely or critically sick or injured child in the District General Hospital: A team response [1]. This document outlined the responsibilities of health services and health professionals in providing care for the seriously ill child. It emphasised the importance of a team approach, including the role of the anaesthetists and their role in the team. Six key, generic skills are expected of all health professionals involved with the care of sick children in the district general hospital (DGH). These are:

  • 1 To recognise the critically sick or injured child;
  • 2 To initiate appropriate immediate treatment;
  • 3 To work as part of a team;
  • 4 To maintain and enhance skills;
  • 5 To be aware of issues around safeguarding children;
  • 6 To communicate effectively with children and carers.

The DoH paper recognises the role that anaesthetists should have in the assessment, initial management and stabilisation of the sick child. Whilst in many cases, tertiary paediatric centres will provide retrieval services for children, the report does recommend that DGH staff should provide care during transfer for patients who cannot wait for a retrieval team, such as those with head injury or intracranial haemorrhage.

It has recently been demonstrated that DGH staff are able to stabilise critically ill children appropriately in the majority of cases, for example, by performing the majority of tracheal intubations [2].

This article describes aspects of care of both medical and surgical paediatric emergencies, which may become life-threatening, and which an anaesthetist working at a DGH may encounter whilst providing on-call or emergency services.

This article is not comprehensive as there are many aspects of paediatric emergency care that anaesthetists may become involved with. These include acute pain management in children (e.g. sickle cell crisis), assistance with the management of procedural pain and vascular access procedures in emergency situations. Also not covered are non-life-threatening surgical emergencies (e.g. testicular and ovarian torsion) and those conditions that affect both adults and children and have similar management approaches (e.g. anaphylaxis, diabetic ketoacidosis).

Paediatric respiratory emergencies

Acute respiratory illnesses are one of the most common reasons for presentation of children to hospital. Although the need for involvement of anaesthetists in the care of these children is rare, when anaesthesia care is required it can be at short notice and require the rapid assessment and management of an extremely unwell child.

Infants with respiratory illness are at greater risk from rapid deterioration due to their relatively higher oxygen consumption, smaller functional residual capacity and greater airway resistance. The cartilaginous components of their airway are softer and render the airway prone to dynamic obstruction with increased negative pressure as it occurs in respiratory distress. By Hagen-Poiseuille’s equation, resistance to flow is inversely proportional to the fourth power of the radius. This means that significant increases in airway resistance can occur with only small amounts of mucosal swelling within the airway. Due to unfavourable respiratory mechanics, children develop respiratory failure quickly due to muscle fatigue.

It is vital that the anaesthetist makes a comprehensive assessment of the degree of respiratory distress with a thorough history and careful examination. Evidence of increased respiratory effort includes tachypnoea, accessory muscle use, intercostal, subcostal or suprasternal recession, and abnormal sounds such as stridor, wheeze or grunting. Difficulty talking or feeding is also significant. Diminished breath sounds may be evidence of impending respiratory arrest and can be due to obstruction or exhaustion.

Further evidence of hypoxia and respiratory distress should be sought by continuous pulse oximetry and also reduced conscious state, agitation and confusion. Cyanosis is often difficult to detect and its absence does not rule out respiratory failure.

The management of the child with severe respiratory disease should follow a similar structured approach as for the child with trauma with sequential attention to airway, breathing and circulation.

Stridor

The most common cause of stridor in children is viral croup (acute viral laryngotracheobronchitis). Less common causes include non-infectious (spasmodic) croup and an upper airway foreign body (AFB). Rarer causes of stridor in the absence of trauma or burns include tonsillitis, anaphylaxis, tracheitis, diphtheria and epiglottitis.

Croup

Croup is a common childhood respiratory illness, with a peak incidence in the age range of 6 months to 3 years. It is estimated to affect 3% of children younger than 6 years annually [3]. Classically, croup presents with a barking cough, that may be preceded by mild fever and runny nose. The cough often appears suddenly and stridor and respiratory distress may follow. Fewer than 5% of patients with croup require admission to hospital and approximately 1% require tracheal intubation [4–6].

The management of severe croup is initially supportive. The child should be kept with the parent or carer, unnecessary distress should be avoided, continuous oximetry commenced and oxygen applied as tolerated. A child who requires oxygen with an upper airway obstruction must be monitored carefully for signs of respiratory failure as desaturation is usually a late feature.

Nebulised adrenaline improves symptoms within 30 min, but this effect will wear off by 2 h [7]. Advanced Paediatric Life Support (APLS) teaching recommends a dose of 0.5 ml.kg−1 of 1:1000 adrenaline up to a maximum of 5 ml and this may be repeated [8]. Glucocorticoids improve croup symptoms within 6 h of administration and this effect will last approximately 12 h [9]. Steroids have been shown to reduce the need for tracheal intubation [10]. Oral dexamethasone (0.15 mg.kg−1) or prednisolone (1 mg.kg−1) is recommended [8].

If the child remains in significant respiratory distress, has signs of impending exhaustion and has evidence of hypoxia in room air, then tracheal intubation should be considered.

Tracheal intubation within the first hour of presentation is only required in the minority of cases; thus there may be time for adequate assessment and for steroid therapy to take effect [11].

Induction of anaesthesia for tracheal intubation in croup is usually by inhalation [11]. The supraglottic anatomy and vocal cords should be easy to identify, but the subglottis and trachea will be narrowed and a smaller size of tracheal tube should be selected. Intubation should be straightforward, but the presence of pre-existing subglottic stenosis, which exacerbates symptoms, may be a risk factor for difficult intubation [11]. Following intubation, the tracheal tube should be secured and the child allowed to emerge from anaesthesia.

Airway foreign body

An AFB is a potentially life-threatening event and a very common cause of non-intentional injury in children. The mean age is 3 years and over 50% of cases are younger than 2 years of age. [12]. It was previously thought that death is extremely rare once the child with an AFB reaches hospital, but recent analysis of nearly 3000 cases of children admitted to hospital with airway obstruction caused by a AFB showed a hospital mortality rate of 3.4% [12].

The anaesthetist may be involved in the management of a child with an AFB from his/her first presentation to hospital. The presenting symptoms vary according to the size, position and mobility of the foreign body and the time of inhalation. Usually there is a history of a choking episode if the incident was witnessed. Cough, wheeze and dyspnoea may also be present. Upper tracheal or glottic foreign bodies may present with stridor and/or voice change. Later presentations may include fever, productive cough and progressive respiratory distress. Auscultation of the chest may reveal localising signs. Stable symptoms and signs usually indicate that the foreign body is not mobile. A history of fluctuating symptoms such as intermittent stridor may be an indicator of a mobile foreign body, which can be life-threatening. Of all the presenting symptoms and signs, a choking episode has the highest sensitivity and specificity for an AFB [13, 14].

In the absence of acute obstruction and severe symptoms, a chest X-ray may assist in diagnosis, although most foreign bodies are organic and not radiopaque. Comparison of inspiratory and expiratory films may assist the diagnosis of a bronchial foreign body; hyperinflation of the affected side, due to air trapping beyond the foreign body, is seen on the expiratory X-ray.

The initial management of AFB is aimed at determining the severity and this is simply done by assessing the child’s ability to cough. The presence of an effective cough indicates mild airway obstruction and coughing may result in clearance of an upper AFB. An ineffective cough indicates severe obstruction and if the child is conscious, with mild airway obstruction, then the child should be encouraged to cough with the aim of expelling the foreign body. If stable, he/she requires close monitoring, but no further treatment is necessary until appropriate surgical assessment can be arranged.

The conscious child with an ineffective cough and hence severe obstruction should initially be treated with up to five back blows. There is some divergence in opinion between resuscitation councils as to the next step should back blows not be effective, with the UK Resuscitation Council recommending abdominal thrusts and the Australian Resuscitation Council recommending chest thrusts because of the risk of liver injury with abdominal thrusts [15, 16].

The unconscious choking child should receive cardio-pulmonary resuscitation and advanced life support if necessary. A finger sweep of the oral cavity should only be attempted if the foreign body is visible. Bag and mask ventilation as successful primary treatment has been described in a child with severe obstruction and the experienced anaesthetist may consider this approach [17].

The definitive treatment of an AFB is removal via rigid bronchoscopy. If the child presents at a hospital that cannot provide this service, then the child will require transfer to a specialist centre that can. The child should be transported with a medical escort who can provide appropriate resuscitation as outlined above.

An otherwise well child with distal airway obstruction should be fasted in the usual manner. Before induction bronchoscopy equipment should be checked and the operator readily available to retrieve the foreign body should the child become unstable during induction. Traditional anaesthesia management of the child with an AFB for rigid bronchoscopy consists of an inhalational induction, topical application of local anaesthetic agent to the airway and spontaneous breathing via a circuit attached to a ventilating bronchoscope. Although maintenance with inhalational agents is the classical approach, and Liao et al. recently reported better intra-operative haemodynamic stability with sevoflurane and spontaneous ventilation [18], total or partial intravenous techniques are well described. It is possible to provide positive pressure ventilation via a ventilating bronchoscope and the application of positive end expiratory pressure or full manual ventilation is often required to provide adequate oxygenation and ventilation in the deeply anaesthetised patient. Positive pressure ventilation carries the risk of dislodgement of the foreign body, but a prospective study comparing paralysis and positive pressure ventilation with spontaneous breathing by Soodan et al. found fewer complications in the paralysis group and all patients in the spontaneous group required assisted ventilation to maintain oxygen saturation [19].

Epiglottitis

The introduction of the Haemophilus influenzae type-b (Hib) vaccination has seen a 10-fold reduction in epiglottitis presentations [20]. Therefore, epiglottitis is now rare. It is important to differentiate epiglottis from other causes of stridor because tracheal intubation in the child with epiglottitis can be difficult due to glottic obstruction.

The presence of stridor and drooling is predictive of epiglottitis whereas stridor and coughing strongly suggests croup. Other reliable signs of epiglottitis are a preference to sit, refusal to swallow and dysphagia [21].

Airway management of the child with epiglottitis involves preparation for a difficult intubation, with ear nose and throat surgical backup, careful inhalational induction, maintenance of spontaneous ventilation and intubation using a tracheal tube one size smaller than usual. Antibiotic treatment with a third-generation cephalosporin, following swabs and blood cultures, is recommended [22].

Status asthmaticus

The anaesthetist may become involved in the care of children with severe asthma who are unresponsive to standard treatment. Up to 17% of children brought to US hospitals with status asthmaticus undergo tracheal intubation. There is evidence that intubation rates at peripheral hospitals are far higher than at specialist paediatric centres and it has been suggested that this is due to less aggressive medical therapy and lack of experience in the management of severe asthma in children at peripheral hospitals [23, 24].

The presentation of status asthmaticus in children is variable. In most cases, there is a previous history of asthma and evidence of respiratory distress with cough, wheeze and increased work of breathing. The degree of wheeze does not correlate well with the severity of asthma [25]. An absence of breath sounds (a ‘silent chest’) may indicate minimal air entry and impending respiratory arrest. Other evidence of impending arrest may include restlessness, confusion, inability to speak, inability to lie down, pulsus paradoxus, hypercapnia and hypoxia [26].

Oxygen therapy should be commenced if not already. Inhaled β-adrenoceptor agonists and corticosteroids continue to be the mainstays of treatment for severe asthma and a Cochrane review has concluded that the addition of aminophylline does not achieve further bronchodilation and results in more adverse events [27]. Intravenous magnesium sulphate has been shown to be effective in severe asthma [28, 29].

Intubation and mechanical ventilation should be avoided if possible due to the risk of barotrauma, cardiovascular collapse and aggravation of bronchospasm [30]. Non-invasive positive pressure ventilation has been shown to be effective in children and may reduce the need for intubation [31–33].

Deho et al. have described the indications for tracheal intubation in status asthmaticus as:

  • 1 Cardiorespiratory arrest.
  • 2 Respiratory arrest.
  • 3 Acute severe hypoxaemia.
  • 4 Severe hypercapnia (> 10 kPa) with clinical signs of life-threatening asthma (silent chest, poor respiratory effort, altered consciousness, cyanosis, SpO2 < 92%).
  • 5 Progressive clinical deterioration (increasing respiratory distress, physical exhaustion, altered mental status) refractory to medical management [30].

Clinical deterioration and hypercapnia are the most common indications for intubation [30].

Before induction of anaesthesia, hypovolaemia should be corrected as this may exacerbate hypotension due to the decreased venous return caused by positive pressure ventilation, concomitant medical therapy and induction agents. A rapid sequence induction is recommended [26]. Traditionally, ketamine (1–2 mg.kg−1) has been suggested as the induction agent of choice because of its bronchodilator properties. Inhalational induction with sevoflurane is often used, but may result in hypotension [30].

The ventilation strategies for children are similar to those for adults with severe asthma and are aimed at providing adequate oxygenation whilst limiting lung trauma and haemodynamic instability. Outcome will be improved by limiting airway pressures and using a low respiratory rate and tidal volume. A moderate degree of hypercapnia and respiratory acidosis is acceptable [34]. Once intubated, volatile agents may be useful in the treatment of asthma, although they may be difficult to administer during transfer between hospitals [35, 36].

Sepsis

Sepsis is a significant cause of morbidity and mortality in children. In 1995, sepsis was the second most common cause of death in children aged 1–14 years in the USA and the mortality rate of children with severe sepsis was 10% [37]. The APLS course defines septic shock as sepsis with cardiovascular organ dysfunction [8].

The most common bacterial cause of septic shock in children in the UK is meningococcal sepsis [38] and this disease is notable for almost exclusively affecting previously healthy children [39].

Septic children presenting to a DGH often require a multidisciplinary team, including anaesthetists, who can provide expertise in airway management, ventilation and vascular access.

The clinical diagnosis of septic shock in a child with suspected infection can be made if the child has hypothermia or hyperthermia and clinical signs of inadequate tissue perfusion including any of the following; decreased or altered mental status; prolonged capillary refill (>2 s); diminished pulses; cool peripheries; bounding peripheral pulses; wide pulse pressure; or decreased urine output. Hypotension may not always be present [40].

Both APLS teaching and the American College of Critical Care Medicine (ACCCM) recommend the airway, breathing and circulation (ABC) approach to management of septic shock, with the goals of resuscitation being maintenance or restoration of airway, oxygenation, ventilation and circulation [8, 40]. Boluses of 20 ml.kg−1 isotonic fluid should be given. After the second bolus, if signs of shock persist, inotropic support, intubation and ventilation should be considered. Up to 200 ml.kg−1 may be required in the first hour although 40–60 ml.kg−1 is more common. Central venous access should be attempted, with a femoral line recommended for those not experienced in the internal jugular approach in children. If central access is not possible then inotropes may be administered in dilute solutions via a peripheral or intraosseous line.

It has long been established that early aggressive fluid resuscitation is associated with improved outcome in paediatric sepsis [41]. A recent UK study has shown that 62% of children with septic shock did not receive fluids according to the ACCCM guidelines [38].

As a significant proportion of cardiac output is used for maintaining ventilation, tracheal intubation and assisted ventilation can reverse shock. The ACCCM guidelines recommend the use of ketamine for induction, to help maintain circulation, after volume loading and with inotropic support available [39].

Status epilepticus

Convulsive status epilepticus (CSE) is defined as a single convulsion lasting more than 30 min or two or more convulsions lasting more than 30 min without recovery of consciousness.

Convulsive status epilepticus is the most common neurological emergency in children and is more common than in adults albeit with a lower risk of death [42]. Common causes of CSE include prolonged febrile seizures, acute central nervous system infection, epilepsy, hypoxia and metabolic abnormalities such as hypoglycaemia.

The anaesthetist’s role in the management of CSE includes airway management and assistance with administration of anticonvulsant medication. The management of CSE, as for all seriously ill children, should follow an ABCDE approach, as recommended by APLS and NHS guidelines [8, 43].

By the time the anaesthetist is involved, the child with CSE may have received a number of anticonvulsants, including benzodiazepines, phenytoin and phenobarbital. Blood glucose and electrolytes should be checked and hypoglycaemia should be corrected if present.

NHS guidelines recommend up to two doses of intravenous benzodiazepine, with lorazepam 0.1 ml.kg−1 preferred. If CSE persists, phenytoin 20 mg.kg−1 (over 20 min) should be given, escalating to phenobarbitone 20 ml.kg−1 given over 5 min if fitting continues or if the patient is already on phenytoin [8].

The final escalation in the treatment of uncontrolled CSE is rapid sequence induction with thiopental (4 mg.kg−1). Propofol has been used successfully in the management of CSE and is an alternative to thiopental according to APLS guidelines [8, 44]. The use of long-term neuromuscular blockade should be avoided as this may make it difficult to detect further seizures. Infusions of general anaesthetic agents carry the risk of cardio-respiratory depression and appropriate monitoring and management must be commenced, particularly if transfer to another hospital is warranted.

Recently, levetiracetam has been shown to be effective in the treatment of CSE in children [45, 46]. It has been proposed that this agent has a role in management protocols for status epilepticus [47].

The acute abdomen in the newborn

Management of the acute abdomen in the neonate is very familiar to the specialist paediatric anaesthetist. Occasionally, non-specialist paediatric anaesthetists will become involved either at delivery or before transfer from a medical neonatal unit to a unit with surgical capability.

Gastroschisis and exomphalos are the most common abdominal wall abnormalities and involve a defect in which the intestine and possibly other organs are prolapsed outside the abdomen. These conditions are obvious at birth and are often diagnosed antenatally by ultrasound.

Peritonitis in newborns is most often caused by necrotising enterocolitis, which occurs in up to 3 per 1000 live births and has an association with prematurity and low birthweight [48]. Peritonitis rarely occurs before an infant is fed and is rare in the first 24 h of life. Presentation may initially be non-specific with feeding intolerance, abdominal distension, delayed gastric emptying, bile stained nasogastric tube aspirates, apnoea and respiratory distress [49]. These symptoms and signs may be followed by sepsis, anaemia, thrombocytopenia, coagulopathy and metabolic acidosis.

Management of the newborn with an acute abdomen follows similar principles to those of adults. Particular attention must be paid to circulatory status and fluid resuscitation. Babies with gastroschisis or exomphalos should have the defect covered by sterile plastic wrapping as soon after birth as possible. This reduces the risk of dehydration and hypothermia. It may also reduce infection.

If there is significant respiratory distress, then tracheal intubation should be considered. This will allow adequate pain relief to be given without the risk of apnoea and hypoventilation. Once intubated, large tidal volumes (> 8ml.kg−1) should be avoided. Volume-targeted ventilation has been shown to reduce bronchopulmonary dysplasia and the incidence of pneumothorax and neonatal brain injury [50]. Pre-term infants should be given supplemental oxygen to maintain oxygen saturations between 88% and 92%. Oxygen toxicity in this group has been shown to contribute to retinopathy of prematurity and bronchopulmonary dysplasia [51].

Assessment of circulation in the newborn with an acute abdomen can be challenging; cool peripheries, poor capillary refill, tachycardia and hypotension indicate profound hypovolaemia. Normal values for blood pressure in some groups of healthy term babies have been found to be surprisingly high with mean arterial blood pressures over 70 mmHg at two days of age rising to over 90 mmHg at six weeks [52]. There has been difficulty in defining hypotension in children, although surveys of paediatric anaesthetists have indicated that hypotension can be defined as 20–30% reduction from baseline systolic pressure. For pre-term infants, the lower limits for mean arterial pressure have been shown to be numerically similar to gestational age (e.g. an infant at 32 weeks post-conceptual age should have a mean arterial pressure of at least 32 mmHg) [53].

Intussusception

Intussusception is one of the most common causes of bowel obstruction in children. Intussusception is an emergency and, if not treated, may lead to bowel ischaemia, perforation and death.

The annual incidence of intussusception in infants in the UK is 66 per 100 000 with a peak in those aged 3–6 months [54].

Intussusception occurs when a segment of bowel invaginates into a more distal segment, classically at the ileo-caecal junction (in over 80% of cases), leading to venous compression, oedema and vascular compromise of the bowel [55]. If left untreated, necrosis and/or perforation of the bowel may occur.

Clinical diagnosis may be difficult because the presenting symptoms may be non-specific and may include vomiting, crying, lethargy, irritability and pain. The classic triad of emesis, pain and bloody stools may only be present in up to 45% of cases [55, 56]. An abdominal mass may be present and the diagnosis, if suspected, can be confirmed by air enema. An infant with intussusception may present with evidence of hypovolaemia and appear seriously unwell.

Infants with intussusception present, not infrequently, at district and regional hospitals and anaesthetists may be involved in their care including resuscitation, care while undergoing air enema, preparation for transfer and transfer itself.

The treatment of choice for intussusception is air enema under fluoroscopic control [57]. This technique has a success rate as high as 82% [56]. Whilst urgent treatment of intussusception is the priority, it is important that hypovolaemia is recognised and anticipated. The infant should have secure intravenous access and be treated with adequate volumes of fluid (ideally 20–30 ml.kg−1 of an isotonic solution). It is reasonable for an anaesthetist to accompany the infant for fluoroscopy. Sedative drugs and general anaesthesia are not usually necessary, but the anaesthetist should carefully monitor the cardiorespiratory and fluid status and take measures to prevent and treat hypothermia. Failed air enema is not uncommon and a repeat air enema may be effective [56]. If air enema does not reduce the intussusception, laparotomy performed by a paediatric surgeon is indicated. At this point, transfer to a tertiary centre should be considered. These procedures take time and the child may suffer further fluid loss leading to dehydration and shock. Operative reduction may result in resection of ischaemic or abnormal bowel. The presence of hypovolaemic shock increases the likelihood of bowel resection [56].

Management of the child with a bleeding tonsil

Tonsillectomy is one of the most common paediatric surgical procedures. Post-tonsillectomy bleeding is a serious complication. Primary bleeding (within the first 24 h of surgery) occurs in up to 2% of patients, and secondary bleeding in up to 5.5% of patients, with a peak incidence between postoperative days 4 and 7 [58, 59]. Therefore, the patient with bleeding tonsils may present as an inpatient or via the emergency department as an outpatient.

Major post-tonsillectomy haemorrhage may be sudden and dramatic with hypovolaemic shock and airway obstruction the greatest risks to the patient [60]. As rapid deterioration is possible, there may be some urgency to proceed to the operating theatre for surgical management of bleeding.

Assessment of the patient with post-tonsillectomy haemorrhage can be challenging as the child may be distressed. Calculating the volume of blood loss may be difficult as the child may have swallowed significant amounts. Intravenous access should be secured and intravenous fluid resuscitation commenced. Haemoglobin and coagulation profiles should be checked and cross-matched blood arranged. The difficult intubation trolley and two suction units should be available in case one becomes blocked with blood clot before induction.

There is a paucity of published papers on the anaesthetic management of post-tonsillectomy bleeding. Both intravenous and inhalational induction techniques have been described, with a rapid sequence induction being the most common approach [61, 62]. A smaller tracheal tube than used previously may be required because of airway oedema.

A recent retrospective study reviewed 475 patients requiring surgical management of bleeding following 16 596 tonsillectomies (a return-to-theatre rate of 2.9%). There were no deaths and only three patients required intra-operative blood transfusion. The most common adverse events were hypoxaemia (9.9%), mainly during emergence or extubation, bradycardia on induction (4.2%) and hypotension (2.5%). A difficult intubation rate of 2.7% was recorded but in none of these patients was to be a difficult intubation noted at the time of tonsillectomy [62].

Trauma in children

Trauma is responsible for the majority of deaths in children > 1 year of age and accounts for almost 40% of deaths in children in developed countries [63].

The injured child may present to district hospitals and anaesthetists are integral to the successful management of major paediatric trauma; they may be involved in the acute resuscitation, anaesthesia for emergency surgical procedures and medical imaging, care in intensive care units, pain management and transfer to specialist centres.

Outcomes after trauma in children are best in specialist paediatric centres; however, injury victims are still often taken to the nearest hospital [64].

Road traffic accidents and falls are the main causes of severe paediatric trauma and head injuries are the main cause of death, particularly in infants [65].

There is widespread acceptance and use of the structured approach to the injured child as taught on courses such as APLS, Advanced Trauma Life Support (ATLS) and Primary Trauma Care [8, 66, 67]. The approach to the injured child is similar to that of the injured adult, although there are some important differences that should be noted.

Management of the paediatric airway may pose challenges for those unfamiliar with children. Infants and babies have a larger head and higher, more anterior larynx compared with older children and adults. The higher metabolic rate in young children combined with the decreased functional residual capacity that is often seen in trauma patients will result in a rapid desaturation if airway management is not optimal.

Although the incidence of spinal cord injuries in children is low, the cervical spine should be immobilised, where possible, until injury has been excluded [68]. Therefore, anaesthetists must be familiar with the range of paediatric stiff neck collars and understand how these are sized and applied.

Rib fractures and flail chest are less common in children than adults but haemothorax and pneumothorax may be present without external evidence of injury and must be suspected in all major trauma.

Children in distress often swallow air and this may result in a full stomach which can further reduce functional residual capacity, cause respiratory distress, make abdominal assessment difficult and increase the likelihood of nausea and vomiting. This makes pre-oxygenation vital before tracheal intubation and early insertion of a nasogastric tube is advisable.

Blood pressure is an unreliable guide to circulatory status in children and injured children may be normo- or hypertensive regardless of the severity of injury [69]; therefore other signs of shock, such as peripheral circulatory restriction, tachycardia and confusion, should be recognised. There is evidence that capillary refill time (CRT) correlates with circulatory status and delayed CRT may indicate shock [70]. If bradycardia is present, a head injury should be suspected [71].

Obtaining vascular access is a priority and peripheral venous cannulation is preferable. The long saphenous vein at the ankle and the external jugular veins are often overlooked. Intra-osseous cannulation of the tibia is a very effective and reliable method of gaining vascular access and is advised before attempts at central venous cannulation [8]. In blunt trauma, hypovolaemia should be treated with a bolus of 20 ml.kg−1 isotonic fluid, followed by reassessment and further boluses as required. In penetrating trauma and uncontrolled haemorrhage, 10 ml.kg−1 should be given as the initial bolus, and after a total of 20 ml.kg−1, surgical opinion should be sought if the signs of circulatory compromise are still evident. The administration of blood should be considered after giving 40 ml.kg−1 of crystalloid in total [8].

After airway, breathing and circulation have been stabilised, an assessment of disability should be made using the AVPU scale (Alert, responsive to Voice, responsive to Pain or Unresponsive). Formal Glasgow Coma Scale (GCS) assessment should take place as part of the secondary survey. During the primary survey, careful attention should be paid to keeping the injured child warm.

The critical role of appropriate pain management has been recognised in paediatric trauma, and anaesthetists who may be involved with injured children must have good working knowledge of appropriate drugs and techniques.

The child with burns

Management of the burnt child can be extremely challenging and anaesthetists are often involved in the acute resuscitation of a burnt child before stabilisation and transfer to a specialist burns centre. In particular, the anaesthetist may be asked to provide expertise in airway management, ventilation, vascular access, fluid management, analgesia and assistance with transfer.

The general approach for the burnt child, as for any injured child, should be assessment and management of ABC. In patients with scalds, it is rare for the larynx and pharynx to be swollen directly from the burn, but the face and tongue can become severely oedematous leading to upper airway obstruction. Early tracheal intubation is indicated in these patients and for those who have had an inhalational injury. Intubation should also be considered for those patients requiring large amounts of analgesics and before escharotomy.

A systemic inflammatory response in large burns (> 30% of body surface area) may result in decreased pulmonary function secondary to pulmonary oedema and pulmonary hypertension. Intubation and ventilation will ensure optimal respiratory function over the first 48 h. The airway usually continues to swell during the first 48 h after burn injury and this must be remembered when selecting the correct tracheal tube size. The use of cuffed tracheal tubes in burns patients has been shown to reduce the number of respiratory complications and re-intubations and improve the effectiveness of ventilation [72]. The use of suxamethonium within the first 24 h of burn injury is considered safe and will not result in significant hyperkalaemia [73]. Securing the tracheal tube in a patient with facial burns can be difficult and consideration should be given to fixation via a dental brace [74].

Assessment of the circulation is challenging in the distressed child. Heart rate and respiratory rate will be elevated due to pain and anxiety as well as hypovolaemia. As mentioned in the section on trauma, normal or high blood pressure may be present in shock. Mental state, urine output and signs of peripheral vasoconstriction such as delayed CRT may be useful in diagnosing shock [70]. It is unusual for burns patients to be profoundly hypovolaemic secondary to dehydration in the first 2 h after a burn, and significant hypovolaemia immediately post-injury is more likely to be due to another injury.

Early intravenous access is essential as tissue swelling may make cannulation difficult. It is preferable to cannulate veins through unburnt skin and consideration should be given to intra-osseous access in difficult cases.

Initial fluid resuscitation should be with crystalloid and according to the modified Parkland formula although care should be taken to avoid over-resuscitation as this can lead to pulmonary oedema and abdominal compartment syndrome [75–77]. A urine output of > 0.75 ml.kg−1.h−1 should be the aim.

Pain from thermal injury is particularly severe. Strong analgesia should be administered as soon as the primary survey has been completed and titrated until adequate pain relief is achieved. Multi-modal analgesia is useful during the acute phase of pain management and agents such as ketamine, tramadol, paracetamol and non-steroidal anti-inflammatory drugs may be useful adjuncts to opioids.

Traditional teaching is that escharotomy requires minimal analgesia or anaesthesia because it was thought that most of the burns causing limb constriction are full thickness and therefore have little sensation. However, most burns, especially scalds, have a significant component of partial thickness burn and escharotomy will be a painful procedure as sensory nerves in the burnt area will be intact. Escharotomy for children is usually performed under general anaesthesia.

The decision to transfer a burns patient to a specialist referral centre is based on the size and site of the burn. Generally, any burns patient with whom an anaesthetist has been involved in resuscitating, will be under consideration for transfer after stabilisation.

Conclusion

Anaesthetists working at peripheral hospitals have a critical role in the assessment, initial resuscitation, stabilisation and transfer of sick children. A knowledge of life-threatening paediatric medical and surgical conditions is essential for those who provide emergency or on-call services. This article outlines the evidence for currently accepted care during such conditions.

Competing interests

No external funding or competing interests declared.

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