Internal MedicineInfectious DiseaseSepsis and Septic Shock

Sepsis and Septic Shock

Must-Not-Miss / Red Flags

  • Lactate >4 mmol/L: tissue hypoperfusion – high mortality
  • Refractory hypotension: not responsive to 30 mL/kg crystalloid
  • Purpura fulminans: DIC with meningococcemia
Patient Explanation
“You have a serious infection that has spread throughout your body and is affecting your organs. We’ll give you strong antibiotics and fluids to fight the infection and support your blood pressure.”
Board Fact
“The SOFA score (Sequential Organ Failure Assessment) defines organ dysfunction in sepsis; a change of ≥2 points indicates sepsis.”
ICD-10
R65.20

Definition & Core Concept

Sepsis is a life‑threatening organ dysfunction caused by a dysregulated host response to infection. Septic shock is a subset of sepsis with persistent hypotension requiring vasopressors and elevated lactate >2 mmol/L despite adequate fluid resuscitation.

Epidemiology & Risk Factors

  • Affects 49 million people globally annually; 11 million deaths
  • Most common cause of death in hospitalized patients
  • Common sources: pneumonia (50%), intra‑abdominal (25%), urinary tract (15%)

Pathophysiology (Rule of 3)

  1. Pathogen recognition by innate immune cells (TLR, NOD) → cytokine storm (TNF‑α, IL‑1, IL‑6)
  2. Endothelial dysfunction → capillary leak → hypovolemia
  3. Microvascular thrombosis and mitochondrial dysfunction → tissue hypoxia → multi‑organ failure

Clinical Presentation

  • Fever or hypothermia, tachycardia, tachypnea
  • Altered mental status, oliguria, mottled skin
  • Hypotension (MAP <65 mmHg) despite fluids = septic shock

Diagnostic Workup

Blood cultures x2 before antibiotics. Lactate: elevated. CBC, BMP, LFTs, coagulation panel. Chest X‑ray and urinalysis to identify source. Procalcitonin: can guide antibiotic duration.

Management Protocol

  1. 1‑hour bundle: Blood cultures, lactate, antibiotics, IV fluids (30 mL/kg crystalloid), vasopressors if hypotensive
  2. Empiric antibiotics: within 1 hour; broad‑spectrum (e.g., Vancomycin + Cefepime)
  3. Source control: drainage of abscess, removal of infected lines
  4. Vasopressors: Norepinephrine first‑line; add Vasopressin or Epinephrine if refractory
  5. Corticosteroids: consider if refractory shock (Hydrocortisone 50 mg IV q6h)

Complications & Prognosis

  • ARDS, acute kidney injury
  • Disseminated intravascular coagulation (DIC)
  • Critical illness polyneuropathy/myopathy
  • Long‑term cognitive impairment (post‑sepsis syndrome)

ICU Criteria

All patients with septic shock require ICU admission for vasopressor titration and invasive monitoring.

Clinical Vignette

A 65‑year‑old man with diabetes is admitted with fever, confusion, and hypotension. He has a chronic foot ulcer. WBC is 22,000, lactate 4.5 mmol/L. Blood cultures grow MRSA.

Pearls & Pitfalls

  • Early, appropriate antibiotics reduce mortality by 7% per hour of delay.
  • A normal WBC does not rule out sepsis – leukopenia can occur in severe infection.

Discharge & Follow-Up

De‑escalate antibiotics based on culture sensitivities. Physical therapy and rehabilitation. Monitor for post‑sepsis syndrome.

Literature & Guidelines

Surviving Sepsis Campaign Guidelines 2024. PMID: 38579152.

Personal Clinical Notes