Sepsis and Septic Shock Quiz

Infection

• Infection is the presence of microorganisms in normally sterile host tissue.
• Bacteremia is the presence of viable bacteria in the blood.

Spectrum of Infection

• Sepsis is the systemic response to infection.
• Severe sepsis is sepsis associated with organ dysfunction, hypoperfusion, or hypotension.
• Septic shock is sepsis with hypotension despite adequate fluid resuscitation, and perfusion abnormalities.

SIRS (Systemic Inflammatory Response Syndrome)

• SIRS is an exaggerated systemic inflammatory response to a variety of severe clinical insults.
• It is manifested by 2 or more of the following conditions:
  • Temperature >38 °C or <36 °C
  • Heart rate >90 beats/min
  • Respiratory rate >20 breaths/min
  • White blood cell count (WBC) >12,000 (Leukocytosis) or <4,000
  • Blood glucose >2 mmol/L

Management of Sepsis

• Obtain cultures (blood, urine, sputum, etc.) prior to administration of antibiotics.
• Administer broad-spectrum IV antibiotics within 1 hour.
• Initial fluid resuscitation of 30 mL/kg crystalloid for hypotension or lactate >36 mg/dL (≥4 mmol/L).
• Use vasopressors if Mean Arterial Pressure (MAP) is <65 mmHg.

Typhoid Fever

• Typhoid fever can have varying clinical courses, ranging from mild to severe, with 10-15% of patients developing severe disease.
• The incubation period is typically 10-14 days, and symptoms include prolonged low-grade fever, dull frontal headache, malaise, myalgia, dry cough, anorexia, and nausea.
• The fever may progress in a stepwise manner to become persistent and high-grade by the end of the second week, lasting up to 4 weeks if left untreated.
• Relative bradycardia at the peak of the fever is an indicator of typhoid fever, although this finding is not universal.
• Rose spots develop on the back, arms, and legs in up to 25% of cases late in the first week of fever.
• Other symptoms include coated tongue, alteration of bowel habits, tender abdomen, and hepatosplenomegaly.

Other Presentations of Salmonella Infection

• Urolithiasis or structural abnormalities and immunosuppressive therapy predispose to Salmonella urinary tract infections.
• Relapses can occur, even with appropriate therapy, and the relapse rate is significantly higher in immunosuppressed patients with Salmonella bacteremia.

Diagnosis

• Blood culture is 80-100% accurate in detecting bacteremia.
• Bacteria appear in the bloodstream within 14 days, facilitating secondary metastatic foci.
• Gallbladder infection can lead to long-term carriage of S typhi or S paratyphi in bile and secretion to the stool.

Transmission

• Salmonella is transmitted through consumption of contaminated foods, including beef, poultry, eggs, fruits, vegetables, dairy products, and shellfish.
• Meat can become infected with Salmonella during production, when bacteria from animal intestines transfer onto meat due to careless processing or improper hygiene.

Causes

• The 7 most commonly isolated Salmonella strains causing human disease reported to the CDC in 2007 include S enteritidis, S typhimurium, S enteritidis heidelberg, S enteritidis newport, S enterica serotype Javiana, S enterica serotype I 4,5,12:i:, and S enteritidis montevideo.
• Enteric fever is caused by S typhi and S paratyphi.

Laboratory Diagnosis

• Freshly passed stool is the preferred specimen for isolation of nontyphoidal Salmonella species.
• PCR is performed, and bone marrow aspirate and culture are superior to blood culture.
• In patients who received antibiotic therapy prior to hospitalization, bone marrow aspirate may still be positive for Salmonella even if blood culture results are negative.

Laboratory Findings

• WBC count is usually within the reference range, but approximately one-fourth of patients with typhoid fever are leukopenic, neutropenic, or anemic.
• Thrombocytopenia is neither universal nor diagnostic.
• Eosinophilia should prompt a search for concomitant parasitic infection.
• Mild hepatocellular liver function abnormality is common.

Imaging Studies

• Radiologic findings in salmonellosis are nonspecific.
• Patients older than 50 years with nontyphoid Salmonella bacteremia should undergo clinical assessments such as CT or MRI to rule out concurrent vascular infections.

Treatment

• Salmonella gastroenteritis is usually a self-limiting disease.
• Fluid and electrolyte replacement may be indicated in severe cases.
• Antibiotics are not routinely used to treat uncomplicated nontyphoidal Salmonella gastroenteritis and are reserved for patients with severe disease or those who are at a high risk for invasive disease.

This quiz tests your knowledge on sepsis and septic shock, including the definition, spectrum, and clinical manifestations of infection.