The Older Child: Sepsis and Septic Shock

Infectious diseases that require intensive care include sepsis with organ dysfunction and septic shock. Sepsis can develop in children from virtually any bacterial or viral pathogen. In a previously well child, sepsis is often accompanied by an obvious primary local site or source of infection. Although older children can usually localize an infection as well as an adult, a younger child does not localize infections well. Of particular note, CNS infections can be difficult to diagnose in children who are younger than 2 years because they are unable to give an adequate history of headache and also because meningismus or other signs of meningeal irritation are not reliable findings.

The most common clinical manifestations of sepsis in the neonatal age group include fever or hypothermia, tachypnea and tachycardia, poor cutaneous perfusion, altered level of neurologic function (agitation and irritability followed by apnea or coma), petechiae, purpura or other rashes, DIC, and the metabolic abnormalities of metabolic acidosis, hypoglycemia, and hypocalcemia. Sepsis can also be associated with septic shock. In septic shock, endotoxin, exotoxin, or other endogenously liberated vasoactive substances produce an endothelial lesion that results in a syndrome of increased vascular permeability with resultant ARDS, increased use of metabolic substrate, depressed myocardial function, and profound DIC.^[336]

The mainstay of therapy for any infection and particularly for septic shock is eradication of the infection. Parenteral broad-spectrum antibiotic coverage should be initiated according to the specific clinical situation, and any septic foci or abscess should be surgically drained. A child in septic shock requires early and possibly massive cardiorespiratory support. Endotracheal intubation and positive-pressure ventilation with increased levels of PEEP are used to support a child with ARDS. Inotropic drugs are often needed to maintain adequate cardiac output and tissue perfusion. A Swan-Ganz catheter can provide useful information in this situation. Because coagulopathies, including thrombocytopenia and generalized factor deficiencies, are common in septic shock, fresh frozen plasma and platelet transfusions may be required. In the past, high-dose steroids, though controversial, were commonly suggested for use in septic shock.^[337] Clinical studies have shown steroids to have at the least no effect and possibly a deleterious effect in septic shock.^[338] The use of these drugs is therefore not advocated, except in the situation of steroid replacement in purpura fulminans with possible Waterhouse-Friderichsen syndrome.

An immunocompromised host differs from a previously healthy child. These children often lack a specific primary focus of infection; in addition, they suffer from attacks by different pathogens: Pseudomonas aeruginosa, E. coli, Klebsiella, Staphylococcus aureus, and coagulasenegative Staphylococcus, as well as fungi (Candida albicans and Aspergillus). ^[339] Immunocompromised children may also suffer polymicrobial sepsis with bacterial seeding from the GI tract. These children may have few if any premonitory signs or symptoms before the development of septic shock. Fever is probably the most common and often the earliest sign of opportunistic infection. Bacterial, fungal, and viral cultures should be obtained, and broad-spectrum antimicrobial therapy should be initiated. Antifungal drugs should also be considered in these patients. Granulocyte transfusions have been reported in neutropenic patients with overwhelming sepsis—usually with a gram-negative organism.^[340] Table 76-19 lists the most common predisposing causes of immunosuppression, along with the most frequently associated opportunistic organisms.^[341]