Chapter 88. Toxic Shock

Toxic shock syndrome (TSS) is a severe, life-threatening syndrome that can progress rapidly to multisystem dysfunction, severe electrolyte disturbances, renal failure and shock. Colonization or infection by Staphylococcus aureus has been implicated in the majority of cases. Although TSS was initially related to menstruating females, now the spectrum of patients at risk includes both genders and all ages. Risk factors for TSS includes recent menstruation, postpartum or postabortion status, cutaneous lesions such as burns, tattoos, piercings, varicella lesions or recent surgical sites, and intracavitary foreign objects such as nasal packing, intrauterine devices, and vaginal sponges.

Clinical Features

TSS is characterized by high fever, profound hypotension, diffuse erythrodermatous rash, mucus membrane hyperemia, diffuse myalgias, nonfocal neurologic abnormalities to include lethargy, agitation, confusion, headache or seizures, vomiting, diarrhea or abdominal pain that can rapidly progresses to multisystem dysfunction, organ failure, and death. The rash associated with TSS is described as a “painless sunburn” that typically fades within 3 days and is followed by full-thickness desquamation.

Diagnosis and Differential

TSS must be considered in any acute febrile illness associated with erythroderma, hypotension, and multiorgan involvement. Diagnostic criteria are listed in Table 88-1. When considering TSS, the evaluation should include arterial blood gas analysis; a complete blood count with a differential count; electrolyte determinations, including magnesium, calcium, creatinine phosphokinase; coagulation panel; urinalysis; electrocardiogram; and a chest x-ray. If neurologic abnormalities are present, a head CT and lumbar puncture should be considered. Other syndromes to consider in the differential diagnosis of TSS include streptococcal TSS (STSS), Kawasaki disease, staphylococcal scalded skin syndrome, Rocky Mountain spotted fever, and septic shock.

Emergency Department Care and Disposition

The most important treatment of TSS consists of early, aggressive fluid resuscitation with continuous monitoring of blood pressure, heart rate, respiratory rate, oxygenation, urinary output, and central venous pressure. Early surgical consultation should be considered for removal of infected tissue. The early use of appropriate antibiotics will not affect the acute disease presentation but will reduce bacterial load, further toxin production, and recurrence.

1. An initial fluid bolus of 1 to 2 L of crystalloid intravenous (IV) fluids (normal saline) should be used initially for hypotension and fluid resuscitation. A central venous pressure catheter should guide further fluid resuscitation. Large volumes of IV fluids may be required (up to 20 L) over the first 24 hours.

2. If needed to maintain blood pressure, start dopamine 5 to 20 micrograms/kilogram/min. If there is no response to an infusion of 20 micrograms/kilogram/min, start norepinephrine to keep the mean arterial pressure at least at 65 mm Hg. Usual doses of norepinephrine range from 2.5 to 20 micrograms/kilogram/min.

3. Fresh-frozen plasma, packed red blood cells, or platelets may be given to correct any coagulation abnormalities (see Chapter 138).

4. All potentially infected sites, including blood, should be cultured before initiating antibiotic therapy.

5. Any foreign bodies such as tampons, piercings, surgical or nasal packing should be removed immediately.

6. Antistaphylococcal antimicrobial therapy with β-lactamase resistant agent, such as nafcillin or oxacillin 2 grams IV every 4 hours, plus clindamycin 600 to 900 milligrams IV every 8 hours. Vancomycin 1 gram every 12 hours or linezolid 600 milligrams every 12 hours may be added if methicillin resistant strains are suspected. Parenteral antibiotics are needed for at least 3 days and then oral for another 10 to 14 days.

7. Other considerations include the use of methylprednisolone and IV immunoglobulin. If no improvement with 6 hours of aggressive therapy, 1 to 2 grams/kilogram of IV immunoglobulin has shown some improvement. (Contraindicated in Immunoglobulin A deficiency.)

STSS is defined as any group A streptococcal infection associated with invasive soft tissue infection, early onset of shock, and organ failure. STSS is very similar to TSS but is associated with soft tissue infection that is culture positive for Streptococcus pyogenes. Labeled the “flesh-eating bacteria” by the news media, group A streptococcal infections cause streptococcal necrotizing fascitis, with mortality rates of 30% to 80%.

Clinical Features

Abrupt onset of soft tissue pain localized to one area that is out of proportion to physical findings combined with fever is the most common presentation of STSS followed closely by shock and multisystem organ involvement. The area of involvement is most commonly the extremities but can be anywhere on the body. The global erythematous rash is much less common in STSS. Vesicles and bullae at the site of soft tissue infection that progress to a violaceous or blue discoloration are ominous signs of necrotizing fasciitis or myositis. Necrotizing fasciitis may develop rapidly and carries a poor prognosis. Adult respiratory distress syndrome develops in 55% of patients.

Diagnosis and Differential

Diagnostic criteria are listed in Table 88-2. Laboratory evaluation includes a complete blood count with differential; arterial blood gas analysis; liver function tests; serum electrolyte, magnesium, and calcium determinations; Creatinine Kinase; a coagulation profile; blood cultures; electrocardiogram; chest x-ray; and urinalysis and cultures of the affected area. Immediate surgical consultation with a CT or MRI of the affected area may help confirm the diagnosis but should not delay consultation. The differential diagnosis is the same as for TSS.

Emergency Department Care and Disposition

1. Treatment is similar to that for TSS, with aggressive fluid resuscitation, central venous monitoring, intensive care unit admission and vasopressors, as needed. Intubation is almost always warranted because of the high incidence of ARDS.

2. Antistreptococcal antimicrobial therapy is started with IV penicillin G 24 million units per day in divided doses plus IV clindamycin 900 milligrams every 8 hours or linezolid 600 milligrams IV every 12 hours. In penicillin-allergic patients ceftriaxone 2 grams IV every 24 hours plus clindamycin 900 milligrams IV every 8 hours can be used. Administration of IV immunoglobulin can be helpful. See details under TSS care.

3. Immediate surgical consultation is mandatory because most patients require debridement, fasciotomy or amputation.