10 month old boy. Taken to GP with h/o sudden onset of fever, vomiting and lethargy for 4 hours. Mother very anxious about child. GP referred child to walk-in clinic at hospital.
History on admission: Feverish and drowsy – sudden onset. 2 episodes of vomiting, 1 soft stool, no rash.
Assessment on admission: Drowsy and pale, dark rings around eyes.
Temp 37.7
CVS: P 181, BP 120/52, CRT 4 secs. Child peripherally shutdown.
RS: RR 32 breathing laboured and child cyanosed.
SaO2 100% in oxygen.
NS: GCS10 then 9, no neck stiffness.
Fine blanching rash on abdo/chest. 1 petechial spot on abdo.
Diagnosis: meningococcal septicaemia
QUESTIONS ON CASE 5
Q 6 of 11: Does the normal blood pressure rule out shock?
YesNo
CORRECT : in children, blood pressure can be normal until shock is advanced.
Further Information
Clinical pathophysiology of meningococcal septicaemia
Increased Vascular Permeability
When meningococci invade the bloodstream, endotoxin is released from the bacteria. This triggers an inflammatory response, with release of inflammatory mediators, which is directed against the endothelial surface lining the blood vessels. One of the main functions of the endothelium is regulation of vascular permeability, and disturbance of this function causes the endothelial lining to become 'leaky', allowing increased passage of protein and water from the intravascular to extra-vascular compartments, causing a 'capillary leak syndrome'. The patient becomes hypovolaemic due to reduction in circulating volume, thus reducing cardiac output.
In compensation for reduced circulating volume, heart rate and contractility increase, and perfusion to skin and the splanchnic circulation is reduced. Therefore signs of hypovolaemia in sepsis include:
Tachycardia
Tachypnoea
Cool peripheries
Reduced urine output
Irritability or lethargy.
Note that in the early phases of septic shock blood pressure is maintained by these compensatory mechanisms. This means that early in shock, children are alert as blood flow to the brain is being maintained at the cost of the other organs.
