Children in shock are usually presented by parents who are aware that their child is worryingly ill or seriously injured even though they may not be able to express their concerns clearly. The child may be presented primarily with a fever, a rash, with pallor, poor feeding or drowsiness or with a history of trauma or poisoning. The initial assessment will identify which patients are in shock
Circulation
Assess the adequacy of circulation.
Cardiovascular status Heart rate
A raised heart rate is a common response to many types of stress (fever, anxiety, hypoxia, hypovolaemia). In shock, tachycardia is caused by catecholamine release, and is an attempt to maintain cardiac output by increasing heart rate in the face of falling stroke volume.
Bradycardia in a shocked child is caused by hypoxia and acidosis and is a preterminal sign.
Pulse volume
Examination of central and peripheral pulses may reveal a poor pulse volume peripherally or, more worryingly, centrally. In early septic shock there is sometimes a high output state which will produce bounding pulses.
Capillary refill
Poor skin perfusion can be a useful early sign of shock. Slow capillary refill (>2 seconds) after blanching pressure for 5 seconds is evidence of reduced skin perfusion.When testing for capillary refill press on the skin of the sternum or a digit held at the level of the heart.
Mottling, pallor, and peripheral cyanosis also indicate poor skin perfusion. All these signs may be difficult to interpret in patients who have just been exposed to cold.
In early shock, there may be a hyperdynamic circulation due to vasodilataion in which peripheries are warm but the capillary refill is delayed.
Blood pressure
Blood pressure is a difficult measure to obtain and interpret especially in young infants. A formula for calculating normal systolic blood pressure is:
80 + (2 Age in years)
Children’s cardiovascular systems compensate well initially in shock. Hypotension is a late and often sudden sign of decompensation and, if not reversed, will be rapidly followed by death.
Serial measurements of blood pressure should be performed frequently.
Effects of circulatory inadequacy on other organs Acidotic sighing respirations
The acidosis produced by poor tissue perfusion in shock leads to rapid deep breathing.
THE CHILD IN SHOCK
• Efficacy of breathing Breath sounds
Chest expansion/abdominal excursion
• Effects of breathing Heart rate
Skin colour Mental status
Pale, cyanosed or cold skin
A core/toe temperature difference of more than 2°C is a sign of poor skin perfusion.
Mental status
Agitation or depressed conscious level. Early signs of brain hypoperfusion are agitation and confusion, often alternating with drowsiness. Infants may be irritable but drowsy with a weak cry and hypotonia. They may not focus on the parent’s face. These are important early cerebral signs of shock. Later the child becomes progressively drowsier until consciousness is lost.
Urinary output
Urine flow is decreased or absent in shock. Hourly measurement is helpful in monitoring progress. A minimum flow of 1 ml/kg/h in children and 2 ml/kg/h in infants indicates adequate renal perfusion.
NOTE: Poor capillary refill, core/toe temperature difference and differential pulse volumes are neither sensitive nor specific indicators of shock when used in isolation.
There are helpful when used in conjunction with the other signs described.
Look for the presence of signs of heart failure
• Tachycardia
• Raised jugular venous pressure (often not seen in infants in heart failure)
• Lung crepitations on auscultation
• Gallop rhythm
• Enlarged liver
And listen for a heart murmur.
Monitor heart rate/rhythm, blood pressure and core/toe temperature difference. If heart rate is above 200 in an infant or above 150 in a child or if the rhythm is abnormal perform a standard ECG.
Disability
Assess neurological function.
• A rapid measure of level of consciousness should be recorded using the AVPU scale.
• A ALERT
• V responds to VOICE
• P responds to PAIN
• U UNRESPONSIVE
• Pupillary size and reaction should be noted.
• Note the child’s posture: children in shock are usually hypotonic.
• The presence of convulsive movements should be noted.
Exposure
• Take the child’s core and toe temperatures.
• Look for a rash: if one is present, ascertain if it is purpuric.
• Look for evidence of poisoning.
THE CHILD IN SHOCK
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Airway
A patent airway is the first requisite. If the airway is not patent an airway opening manoeuvre should be used. The airway should then be secured with a pharyngeal airway device or by intubation with experienced senior help.
Breathing
All children in shock should receive high flow oxygen through a face mask with a reservoir as soon as the airway has been demonstrated to be adequate.
If the child is hypoventilating, respiration should be supported with oxygen via a bag-valve-mask device and experienced senior help summoned.
Circulation
Gain intravenous or intraosseous access.
Take blood for FBC, U&Es, blood culture, cross-match, glucose stick test and laboratory test
Give 20 ml/kg rapid bolus of crystalloid to all patients except for those with signs that heart failure is their primary pathology.
The initial bolus should be colloid and an antibiotic such as cefotaxime 100 mg/kg should be used for those in whom a diagnosis of septicaemia is made obvious by the presence of a purpuric rash.
If a tachyarrhythmia is identified as the cause of shock, up to three synchronous electrical shocks at 0·5, 1·0, 2·0 Joules should be given.
If the arrhythmia is broad complex and the synchronous shocks are not activated by the defibrillator then attempt an asynchronous shock.
A conscious child should be anaesthetised first if this can be done in a timely manner.
If the shocked child’s tachyarrhythmia is SVT then he can be treated with intravenous/intraosseous adenosine if this can be administered more quickly than a synchronous electrical shock.
Circulatory access
A short, wide-bore peripheral venous or intraosseous cannula should be used. Upper central venous lines are unsuitable for the resuscitation of hypovolaemic children because of the risk of iatrogenic pneumothorax, or exacerbation of an unsuspected neck injury; both these complications can be fatal. Femoral vein access is safer, if peripheral or intraosseous access is impossible. It is wise to obtain two separate intravenous and/or intraosseous lines both to give large volumes of fluid quickly and also in case one line is lost.
Techniques for vascular access are described in Chapter 23.
Antibiotics
In paediatric practice, septicaemia is the commonest cause of a child presenting in shock. Therefore, unless an alternative diagnosis is very clear (such as trauma, anaphylaxis or poisoning) an antibiotic, usually a third-generation cephalosporin such as cefotaxime or ceftriaxone, is given as soon as a blood culture has been taken. An anti-staphyloccocal antibiotic (flucloxacillin or vancomycin) should be considered in possible toxic shock syndrome i.e. post burns/cellulitis.
Hypoglycaemia
Hypoglycaemia may give a similar clinical picture to that of compensated shock. This must always be excluded by urgent glucose stick test and blood glucose estimation. Shock and hypoglycaemia may coexist as the sick infant or small child has poor glucose-producing reserves.
Key features
While the primary assessment and resuscitation are being carried out a focused history of the child’s health and activity over the previous 24 hours and any significant previous illness should be gained.
Certain key features which will be identified clinically in the above assessment, from the focused history and from the initial blood test results can point the clinician to the likeliest working diagnosis for emergency treatment.
• A history of vomiting and/or diarrhoea points to fluid loss either externally (e.g.
gastroenteritis) or into the abdomen (e.g. volvulus, intussusception).
• The presence of fever and/or a rash points to septicaemia.
• The presence of urticaria, angio-neurotic oedema and a history of allergen exposure points to anaphylaxis.
• The presence of cyanosis unresponsive to oxygen or a grey colour with signs of heart failure in a baby under 4 weeks points to duct-dependent congenital heart disease.
• The presence of heart failure in an older infant or child points to cardiomyopathy.
• A history of sickle cell disease or a recent diarrhoeal illness and a very low haemoglobin points to acute haemolysis.
• An immediate history of major trauma points to blood loss, and more rarely, tension pneumothorax, haemothorax, cardiac tamponade or spinal cord transection (see Part IV The Seriously Injured Child for management).
• The presence of severe tachycardia and an abnormal rhythm on the ECG points to an arrhythmia (see Chapter 11).
• A history of polyuria and the presence of acidotic breathing and a very high blood glucose points to diabetes (see Appendix B for management).
• A history of drug ingestion points to poisoning (see Chapter 14 for management).