Paediatrics: Bacteraemia and shock

Bacteraemia and shock

Bacterial infection leading to ‘sepsis syndrome’, and shock. The most common cause of bacteraemic shock is Neisseria meningitidis, although Staphylococcus aureus is in increasing as overall proportion and Streptococcus pneumoniae re-mains an important cause even in the era of routine infant 13 valent con-jugate pneumococcal immunization.

Meningococcal septicaemia and shock

Meningococcal disease is rare, but it can be fatal in a previously well child. Unfortunately, at an early stage, the signs and symptoms are non-specific and the child may have features similar to those of a minor viral illness. Meningococcal disease has therefore featured highly in public educa-tion; the ‘glass test’ is used to identify a typical non-blanching purpuric or petechial rash.

Pathogenesis

In the UK, N. meningitides serogroup B is the usual cause of illness. (sero-group C is rare since its inclusion in routine vaccination). The trigger and mechanism of invasion are unknown. Once bacteraemia occurs, bacterial autolysis leads to endotoxin release and systemic illness with disseminated intravascular coagulation, capillary leak, and distributive and cardiogenic shock.

Signs and symptoms

•   Non-specific: fever, malaise, thirst may be the first sign of shock, followed by poor urine output. Pain in proximal muscles, joints, and abdomen is very common.

•   Rash: initially maculopapular, then petechial or purpuric.

•   CNS: associated meningitis in 20–30%. Altered conscious level may be due to shock rather than meningitis and respond to initial fluid therapy. Raised ICP is more common in meningitis presentation (e.g. headache, neck pain or stiffness, irritability, and altered conscious level) than sepsis.

•   Respiratory: features of pneumonia or pulmonary oedema, especially following initial fluid therapy

Diagnosis

Any febrile child who develops a purpuric rash should be considered to have meningococcal septicaemia until proven otherwise.

Management

Suspected cases in the community should receive IV benzylpenicillin (IM if no IV access) as an initial single dose:

·  Children  10yrs, 1g.

•   1–9yr olds, 600mg.

•   <1yr, 300mg.

Suspected cases in hospital should receive 80mg/kg/od ceftriaxone (or cefotaxime 50mg/kg/tds. In shock, 20mL/kg fluid volume should be given immediately, consideration given to repeat fluid boluses followed by

intubation and ventilation and inotropes following early consultation with paediatric intensive care. Careful attention should be made to correc-tion of electrolyte imbalance, particularly potassium (which is low even in anuric renal failure due to meningoccaemia) and calcium. A management algorithm for health professionals based on the NICE clinical guideline 102 is available at M www.nice.org.uk/CG102.

Complications

The majority of survivors of meningococcal disease have few or no se-quelae. However, there is a significant mortality (2–4%), and morbidity includes loss of digits and limbs due to peripheral vascular disease.