Sepsis and septic shock: life-threatening infection emergency¶

Sepsis is the body's overwhelming and life-threatening response to an infection. It occurs when an infection you already have (such as pneumonia, a urinary tract infection, a skin wound, or an abdominal infection) triggers a chain reaction throughout your bloodstream and immune system.

Instead of fighting the localized bacteria or virus, your immune system damages its own tissues and organs. Left untreated, sepsis progresses in hours to septic shock, widespread blood clotting, cardiovascular collapse, and death. Sepsis is a medical emergency that requires the same urgency as a heart attack or stroke.

Do this now: recognizing sepsis and getting emergency help¶

If you or someone in your care has an infection and begins deteriorating rapidly:

1. Call your local emergency number immediately:
   • Call emergency medical dispatch (911 in the United States and Canada, 112 across the European Union, 999 in the United Kingdom, 000 in Australia).
   • Tell the emergency operator clearly: "I suspect sepsis" or "I am concerned this person has sepsis". Using the word sepsis alerts the dispatcher and paramedics to initiate time-critical sepsis screening protocols.
2. Evaluate the TIME warning signs:
   • T (Temperature): Body temperature higher than 38.3 degrees Celsius (101 degrees Fahrenheit), or dangerously low hypothermia below 36.0 degrees Celsius (96.8 degrees Fahrenheit), accompanied by violent shivering and shaking chills.
   • I (Infection): Presence or recent history of an infection, such as pneumonia, kidney or bladder infection, infected cut, dental abscess, surgical wound, or cellulitis.
   • M (Mental decline): Sudden confusion, drowsiness, slurred speech, lethargy, delirium, or difficulty waking up.
   • E (Extremely ill): Severe shortness of breath, rapid breathing over 22 breaths per minute, racing heart rate over 100 beats per minute, pale, mottled, or bluish skin, and a distinct sensation of "I feel like I am dying".
3. Do not wait for a routine clinic appointment:
   • Every hour of delay in administering intravenous antibiotics in septic shock increases the risk of death by approximately 7 to 8 percent. Never adopt a wait-and-see approach overnight if an infection is accompanied by confusion, rapid breathing, or extreme weakness.
4. Position the person safely while awaiting emergency responders:
   • If the person feels faint, weak, or has low blood pressure, lay them flat on their back with their legs elevated 30 cm (12 inches) to help return blood to the brain and heart.
   • If the person has severe respiratory distress or pneumonia, keep their head and shoulders propped upright in a supported seated position to assist breathing.
   • Keep them warm with blankets if they are shaking from chills, but do not overheat them.
   • Do not give food or drink by mouth, as sepsis often causes nausea, vomiting, and a risk of airway aspiration.

Stages of sepsis progression¶

Medical professionals classify the escalation of sepsis into distinct clinical phases:

1. Infection¶

A localized microbial invasion in tissues, such as bacterial pneumonia in the lungs, Escherichia coli in the bladder, Staphylococcus aureus in a surgical incision, or appendicitis in the abdomen. White blood cells fight the pathogen locally.

2. Sepsis¶

The infection escapes local confines, releasing bacterial endotoxins and pro-inflammatory cytokines into the systemic circulation. Widespread inflammation causes microscopic blood clots to form in capillary beds, reducing blood flow to vital organs. Blood vessels dilate and leak fluid into tissues, causing blood pressure to drop.

3. Severe sepsis with organ dysfunction¶

Reduced microvascular perfusion starves major organs of oxygen, leading to acute organ failure:

• Kidneys: Urine output drops sharply or halts entirely, and waste products accumulate in the blood.
• Lungs: Acute respiratory distress syndrome (ARDS) develops as fluid fills the air sacs, causing severe shortness of breath.
• Brain: Toxic metabolic encephalopathy causes acute disorientation, agitation, or stupor.
• Liver and clotting: Platelets drop, causing spontaneous bruising, purple blotches on the skin, and inability to clot blood.

4. Septic shock¶

The most severe, lethal stage of sepsis. Systemic vasodilation causes profound hypotension (systolic blood pressure dropping below 90 mmHg or mean arterial pressure below 65 mmHg) that fails to respond to aggressive intravenous fluid administration. Cells cannot extract oxygen, causing cellular starvation and fatal lactic acidosis.

Sepsis warning signs comparison¶

Who is at highest risk for sepsis¶

Anyone can develop sepsis from a minor cut, insect bite, or common cold, but certain populations face substantially elevated risks:

• Older adults: Adults aged 65 and older account for more than 60 percent of sepsis hospitalizations. Aging immune systems and underlying chronic conditions make early detection harder, as older adults often present with acute confusion rather than high fevers.
• Infants under one year old: Immature pediatric immune systems cannot contain bloodstream infections. Watch for lethargy, poor feeding, cold skin, weak crying, and sunken fontanelles.
• Individuals with chronic medical conditions: People living with diabetes, chronic kidney disease, cirrhosis, heart failure, or COPD.
• Immunocompromised patients: Cancer patients undergoing chemotherapy, organ transplant recipients taking anti-rejection medications, and people with autoimmune disorders taking corticosteroids or biologic therapies.
• Recent surgical or hospital patients: People with recent surgical incisions, central venous lines, urinary catheters, or intensive care stays.

What hospital teams do: the emergency sepsis bundle¶

When an emergency department suspects sepsis, medical teams initiate the Surviving Sepsis Campaign bundle within the first hour of arrival:

1. Measure blood lactate levels: Elevated lactate indicates severe cellular oxygen deprivation and impending shock.
2. Obtain blood cultures: Blood samples are drawn from two separate sites before administering antibiotics to identify the exact bacteria causing the infection.
3. Administer broad-spectrum intravenous antibiotics: Immediate IV antibiotics targeting both Gram-positive and Gram-negative bacteria are started within the first hour.
4. Intravenous fluid resuscitation: Large volumes of isotonic crystalloid IV fluids (typically 30 mL per kilogram of body weight) are infused rapidly to restore intravascular volume and raise blood pressure.
5. Vasopressor medications: If fluid infusion fails to restore blood pressure, doctors administer vasopressors (such as norepinephrine) through a central line to constrict blood vessels and sustain arterial pressure.

... note "Take a course" Hands-on first aid training with the Red Cross, St John Ambulance, or regional emergency medical services teaches essential lifesaving skills with practical, guided experience in recognizing vital sign emergencies.

Related guides¶

• Severe allergic reactions and anaphylaxis
• Heart attack warning signs
• Heat illness and heat stroke
• Emergency numbers by country