Sepsis Basics
On this page
Direct answer
Life-threatening organ dysfunction caused by a dysregulated host response to infection — the Sepsis-3 definition replaces the older "SIRS plus infection" teaching and pushes the bedside screen toward qSOFA: respiratory rate 22 or more, altered mentation, and systolic pressure 100 or less; two of the three should trigger urgency. Septic shock is the further stage where vasopressors are needed to hold mean arterial pressure at 65 mmHg or above despite adequate fluid resuscitation, with lactate above 2 mmol/L. Management follows the Surviving Sepsis Campaign's hourly bundle: measure lactate, take blood cultures before antibiotics, give broad-spectrum antibiotics within the first hour, start 30 mL/kg of crystalloid for hypotension or lactate of 4 or more, add vasopressors as needed, and find the source — drainage of pus, debridement of dead tissue, removal of the infected line or stone. Antibiotics without source control fail; a dental or diabetic-foot infection that drains pus needs a knife alongside the drugs.
What you must remember
- Definitions in a chain: infection → sepsis (organ dysfunction, SOFA score rise of 2 or more from baseline) → septic shock (vasopressor-dependent hypotension with lactate above 2 mmol/L); qSOFA (RR ≥22, altered mentation, SBP ≤100) is the rapid bedside screen, two points warranting full assessment.
- The older SIRS criteria still expected in Indian exams: temperature above 38 or below 36 °C, heart rate above 90, respiratory rate above 20, white cells above 12,000 or below 4,000 — two or more define SIRS but are less specific for sepsis.
- Hour-one bundle: lactate measurement, blood cultures (two sets) before antibiotics, broad-spectrum antimicrobials, 30 mL/kg crystalloid for hypotension or lactate ≥4 mmol/L, vasopressors (noradrenaline first-line) to MAP ≥65 mmHg, and assessment of source control.
- Source control is the surgery in sepsis: drain the abscess (including facial space and dental collections), debride necrotic tissue, remove infected devices and calculi, close leaks — delayed source control is delayed cure.
- Organ support: oxygen and airway control, urine output target 0.5 mL/kg/hour, glucose control, thromboprophylaxis; hydrocortisone only in vasopressor-refractory shock.
- Common surgical sources: chest (pneumonia, empyema), abdomen (biliary, appendiceal, perforation), urinary tract, skin and soft tissue, indwelling lines — and in Indian practice the diabetic foot ulcer and odontogenic facial space infections as everyday admissions.
- Progression markers: falling urine output, rising respiratory rate, new confusion, mottled peripheries, rising lactate with narrowing gap between early recognition and irreversible deterioration.
From a tooth to intensive care: a preventable staircase
A 55-year-old man with type 2 diabetes of fifteen years notices loosening of a lower molar with dull ache; he treats it with analgesics for a week. Pus finds the fascial planes: submandibular swelling, then trismus, then fever with rigors. He reaches hospital with heart rate 118, respiratory rate 26, blood pressure 96/60, confusion, and glucose 340 mg/dL — qSOFA 3 before any blood test returns. The bundle runs as a checklist: lactate drawn (4.6 mmol/L), two sets of cultures sent, piperacillin-tazobactam started within the hour, 30 mL/kg crystalloid given, noradrenaline prepared. But the decisive event of his admission is surgical: incision and drainage of the submandibular space with removal of the offending tooth, plus aggressive diabetic control — no antibiotic regimen, however broad, clears thrombosed, pus-filled planes. Every day of that first week was cheaper than the intensive care unit he now occupies, and every step of the staircase was interruptible: the carious tooth restored, the loose tooth extracted, the swelling drained on day two rather than day seven. Sepsis in dental practice is a story about thresholds — the point at which a local problem becomes a systemic one — and the dentist is often the last professional to see the patient on the right side of that line.
How the exam frames it
The BDS and viva questions align with current teaching: define sepsis and septic shock per Sepsis-3, recite qSOFA, list the components of the hour-one bundle, and explain source control with an example — usually a dental or diabetic-foot collection in Indian settings. MCQs test numbers (RR 22, SBP 100, MAP 65, lactate 2 and 4 mmol/L, 30 mL/kg) and the sequence (cultures before antibiotics, but never delaying antibiotics for imaging). The trap is the older SIRS-versus-qSOFA confusion — candidates quoting SIRS as the current definition lose the update mark — and the reflex of antibiotics alone for a fluctuant collection, which ignores the oldest surgical rule in the book.
Frequently asked questions
What is qSOFA and when is it used?
A rapid bedside screen — respiratory rate 22 or more, altered mentation, systolic blood pressure 100 or less — where two or more criteria should prompt urgent assessment for organ dysfunction in a patient with suspected infection.
How does Sepsis-3 define septic shock?
Vasopressors required to maintain mean arterial pressure of 65 mmHg or above despite adequate fluid resuscitation, with serum lactate above 2 mmol/L, with substantial mortality.
Why are blood cultures taken before antibiotics?
Because even one antibiotic dose sterilises blood cultures in a large share of patients, losing the organism identification that later narrows therapy — but antibiotics themselves must never be delayed for sampling.
What is source control in sepsis?
The physical elimination of the infection source — draining abscesses, debriding necrotic tissue, removing infected lines or stones — without which antimicrobial therapy alone commonly fails.
Which parameters are targeted during resuscitation?
Mean arterial pressure 65 mmHg or above, urine output at least 0.5 mL/kg/hour, and falling lactate — the perfusion endpoints that guide fluids and vasopressors.