The first priority is to rule out upper airway obstruction. Severe obstruction causes cyanosis, while lesser degrees are evident as a rapid respiratory rate, restlessness, anxiety and an increase in respiratory effort manifested by indrawing of the ribs, sternal retraction and use of the ­accessory muscles of respiration. The tongue may fall ­backwards and obstruct the oropharynx in the supine child. This can be overcome by lifting the chin upwards or by pulling the mandible forwards with the fingers behind the angle of the jaw (Fig. 12.4). Secretions, blood and vomitus also may obstruct the upper airway: the mouth and pharynx should be inspected and suctioned clear if necessary. Insertion of an oropharyngeal tube may be necessary to maintain airway patency or, in the unconscious child who is unable to breathe, endotrachial intubation should be performed.

Effective ventilation can be achieved only once the airway is patent. Ventilation is assessed by observing the movement of the chest wall and abdomen, feeling the moist warm air of expiration, and by checking the colour of the patient for cyanosis. Inadequate breathing may require additional oxygen or assisted ventilation (e.g. ‘bagging’ by mask or endotracheal intubation).

External bleeding can be controlled by direct pressure over the wound, digital pressure of the regional artery against a bony prominence (e.g. control of the femoral artery by pressure in the groin, and the brachial artery by pressure against the medial aspect of the mid-humerus) or by elevation of the injured limb. Internal bleeding is suspected from the nature of the injury, superficial bruising and evidence of blood loss (tachycardia, pallor, poor peripheral perfusion, cool periphery and hypotension). Common sites of significant internal bleeding include the chest, abdomen, pelvis, thigh and, in the infant, the head.

Where the injury is isolated, there will be a clear story of direct trauma to the abdomen, for example, a kick in the belly or fall onto a bicycle handlebar (Fig. 12.3), and the patient will complain of abdominal pain. Often, the story will be of progressive pain starting at the time of, or shortly after, the accident. The discomfort may be localized to one part of the abdomen.

The abdomen should be inspected closely for external evidence of trauma such as abrasions, bruising and lacerations. Palpation of the abdomen will demonstrate tenderness.

The age of the child, the mode of injury and external signs will suggest which organ is likely to be injured. For example, a kick to the loin with overlying bruising might suggest a renal injury, whereas a fall onto a handlebar bruising the left hypochondrium would raise the possibility of splenic or pancreatic trauma (Fig. 12.3). Injury to specific organs results in specific effects: the spleen, liver, kidney and great vessels bleed; the bowel leaks its contents; the urinary tract leaks urine; and the pancreas releases exocrine enzymes. Determination of which of these processes has occurred provides further clues as to the affected organ. More specific details are obtained through imaging investigations or laparotomy/laparoscopy.

A child can compensate for moderate blood loss without showing clinical evidence of shock, a fact which leads the inexperienced clinician to underestimate the amount of blood loss. There is a rise in the pulse rate which the unwary may attribute entirely to pain. The blood pressure is normal until a relatively late stage, but then it may drop rapidly. The limbs remain surprisingly warm and well perfused despite moderate blood loss. Remember, however, that limb temperature in a child depends partly on the ambient air temperature and the amount of clothing worn and should be assessed accordingly.

Major blood loss causes pallor, but again other factors contribute to the child’s colour – if vomiting has occurred, many children look pale without any blood loss. Sweating and poor peripheral perfusion are seen with greater degrees of blood loss. In short, it is difficult to estimate the amount of blood loss in children from their general signs until a late stage. Yet, it is important to estimate the amount of blood lost so that adequate fluid resuscitation can be implemented before cardiovascular collapse occurs. Careful examination of the abdomen, therefore, is required to assess the presence and extent of bleeding there.

The signs of intraperitoneal bleeding are (1) distension and (2) tenderness. The distension increases with continued bleeding. Assessment of abdominal distension involves first removing any clothes or blankets which are obscuring the abdomen and then observing the degree of protuberance whilst the patient is lying relaxed in a supine position. The girth can be measured by placing a tape measure around the trunk and under the lumbar lordosis. The exact position of the tape during the first recording should be marked on the skin of the flanks and abdomen. Subsequent measurements at regular intervals will identify progressive abdominal distension. The child’s smaller abdominal cavity makes serial girth measurements more sensitive than in the adult but is subject to certain limitations: free blood within the peritoneal cavity causes a temporary paralysis and dilatation of the bowel (ileus), which increases distension. Likewise, air swallowing increases abdominal distension and makes girth measurements taken in isolation less valuable in the detection of continued intraperitoneal bleeding. The location of maximal tenderness to palpation should be recorded and its severity and extension to other parts of the abdomen observed. Blood irritating the undersurface of the diaphragm causes pain which is referred to the shoulder tip, reflecting the cervical innervation of the muscle.

Retroperitoneal haematomata occur as a result of injury to retroperitoneal organs, the commonest of which is the kidney. The degree of anterior abdominal tenderness on examination is less than with intraperitoneal bleeds, but abdominal distension still occurs because of the retroperitoneal haematoma itself and as a result of the secondary ileus that it produces. Further confirmation of intra-abdominal bleeding may be seen on plain x-rays of the abdomen where fluid displaces adjacent loops of bowel and on observing a fall in the haemoglobin level during the first 12–48 h.

When perforation or laceration of the bowel occurs, intestinal contents leak, usually into the peritoneal cavity. These may be gastric juice, bile, small bowel fluid or faeces according to the site of injury, and each produces signs of rapidly progressing peritonitis. The child looks unwell and toxic. Within hours, the abdomen becomes distended and, while tenderness may be localized initially, it rapidly becomes generalized, severe and accompanied by involuntary guarding. It should be apparent that the signs of perforated bowel and haemoperitoneum are not dissimilar except in:

Nevertheless, it is often very difficult to distinguish the two situations, in which case careful reappraisal of the clinical signs, serial examination at short intervals and recourse to other investigations (e.g. CT scan) may be necessary. An abdominal x-ray showing free gas would confirm gut perforation.

Leakage into the retroperitoneum produces less dramatic signs, and delay in diagnosis is more likely. The child may develop a profound ileus, remain obtunded and be febrile. Retroperitoneal duodenal injury may occur after a lap-belt accident and presents as a high bowel obstruction (duodenal haematoma obstructing the lumen) or with progressive but non-specific signs of sepsis (duodenal laceration and retroperitoneal abscess formation). Pancreatic injuries often present late with a tender epigastric mass, representing a pancreatic pseudocyst.

Direct trauma to the back and loins is more likely to damage the urinary tract than the gastrointestinal tract. A fracture of the pelvis, particularly if it involves the pubic rami, may injure the bladder or urethra. Unless there has been complete interruption of the urethra, there will be haematuria. Therefore, examination of the urine is mandatory where the possibility of urinary tract trauma exists. Injury to the kidney may result in major retroperitoneal haemorrhage causing abdominal tenderness and distension, and signs of blood loss. Disruption of the pelvicalyceal system or transection of the ureter allows urine to leak into the retroperitoneal space, contributing to the retroperitoneal collection. The urinary tract can be outlined by performing a CT with contrast at the time of a plain x-ray or initial imaging of the abdomen. Extravasation of urine is evident as contrast outside the normal urinary tract. In other situations, ultrasonography or nuclear medicine scan may be more appropriate.

The necessity for further investigations depends on:

The organs most commonly injured are the spleen and liver. Where clinical examination suggests that splenic injury is likely to be an isolated lesion and the child is stable, surgery is not required immediately (if at all), and the liver and spleen can be outlined with ultrasound or CT scan with contrast as a non-urgent procedure.

Compression injury of the chest may cause a tear in a major airway with leakage of air into the mediastinum and pleural cavity. Movement of air into the pleural space occurs with each inspiration and remains there during expiration. The volume of air increases with a corresponding rise in pressure (tension). The ipsilateral lung collapses, and there is a shift of the mediastinum to the contra­lateral side, compression of the contralateral lung and interference of venous return to the heart (Fig. 12.8). If uncorrected, inadequate ventilation of the lungs and decreased cardiac output will cause death. Fractured ribs may also lacerate the lung and cause a tension pneumothorax.

Tension pneumothorax should be considered in any patient with a thoracic injury or fractured ribs who develops sudden increasing respiratory distress. Careful clinical examination will confirm the diagnosis. The chest wall moves less on the side of the pneumothorax, with a decrease in ipsilateral breath sounds and hyper-resonance on percussion. Mediastinal shift is detected clinically by deviation of the trachea at the level of the suprasternal notch (Fig. 12.9), and in left-sided lesions, the heart sounds become audible more easily in the right chest. Increased intrathoracic pressure impedes venous return as shown by distended neck veins. The diagnosis can be confirmed on chest x-ray, but in an emergency, immediate insertion of a 14- or 16-gauge needle in the fourth intercostal space at the anterior axillary line, and subsequent insertion of a chest tube connected to an underwater drain, will alleviate the symptoms. The child should be given high-flow oxygen.

Laceration of an intercostal artery associated with fractured ribs causes major blood loss into the thorax (haemothorax). The signs are similar to those seen in tension pneumothorax except that:

The diagnosis is confirmed on chest x-ray. Management involves resuscitation followed by a chest drain or thoracotomy if the major intrathoracic bleeding continues.

In some injuries, the heart is compressed between the chest wall and the vertebral column, causing myocardial contusion with bleeding into the pericardial sac. Much less commonly in children, penetrating wounds (e.g. stab wounds) also may cause bleeding into the pericardium (cardiac tamponade). The pericardial sac prevents effective contraction and refilling of the chambers of the heart and causes hypotension with poor cardiac output. The pulse pressure is narrow, and the pulse volume decreases with inspiration (pulsus paradoxus). The most striking feature is the grossly distended neck veins in the presence of severe pallor and shock. The heart sounds are muffled and difficult to hear.

A diagnostic and therapeutic manoeuvre involves the insertion of a needle just below the xiphisternum directed towards the left shoulder at an angle of 45° to the skin. Aspiration of blood from the pericardium causes immediate and dramatic improvement in the child’s condition until a thoracotomy is performed.

Flail chest is extremely uncommon and seen only in the older child with multiple rib fractures. There is asymmetric movement of the chest wall and a flail segment which moves paradoxically with respiration. It should be assumed that there is contused lung underlying the ribs. Flail chest may cause a significant haemothorax and mediastinal shift with impairment of venous return to the heart and signs of blood loss.

Open pneumothorax virtually never occurs in children but is readily recognized as a wound which transmits air (bubbles and sucks) during ventilation. The defect should be covered to prevent further air movement and a chest tube inserted.

Severe compression of the chest may completely block venous return in the large veins of the thoracic inlet to cause high venous pressures in the head, neck and upper extremities. Small capillaries rupture resulting in petechial skin and subconjunctival haemorrhages. This is relatively common in children and is seen when the child has been run over at low velocity or trapped by a heavy object across the chest. The face, neck and, to a lesser extent, the shoulders and arms are covered with numerous red spots. The cutaneous petechiae resolve after 3 or 4 days, whereas the subconjunctival haemorrhages persist for 1 week or more. In some children, there may be no other injuries, apart from a tyre mark, but in other children, there is an associated major intrathoracic injury.

This is a simple and quick assessment of the neurological status of the child, with a more detailed examination being deferred until initial resuscitation and stabilization (ABC) are complete. This initial examination determines the urgency of neurosurgical care and provides baseline information for the assessment of subsequent progress (Table 12.4).