3. Sepsis and Septic Shock

 

Sepsis and Septic Shock

Sri Lankan Surgery MD Part One / Common Selection Examination Master Note

This is a core Principles of Surgery, critical-care, trauma, physiology, pathology, pharmacology and OSCE topic. Examiners may test it through definitions, postoperative deterioration, source control, fluids, antibiotics, vasopressors, lactate interpretation, organ support and common treatment errors.

The latest international adult guidance is the 2026 Surviving Sepsis Campaign, published on March 23, 2026. Your exam may still quote elements from the 2021 guideline and the traditional “Hour-1 bundle,” so you should know both the current nuanced recommendations and the older examination shorthand. (Society of Critical Care Medicine (SCCM))


1. Essential definitions

Infection

Invasion of normally sterile tissue by pathogenic microorganisms, producing a local or systemic host response.

Sepsis — Sepsis-3 definition

Life-threatening organ dysfunction caused by a dysregulated host response to infection.

Clinically, organ dysfunction is represented by an acute increase in SOFA score of at least 2 points attributable to infection. If no pre-existing organ dysfunction is known, baseline SOFA may be assumed to be zero. (JAMA Network)

Septic shock

A subset of sepsis in which circulatory and cellular/metabolic abnormalities are sufficiently severe to substantially increase mortality.

Operational criteria are:

  1. Sepsis is present.

  2. Hypotension persists despite adequate fluid resuscitation.

  3. Vasopressors are required to maintain MAP ≥65 mmHg.

  4. Serum lactate remains >2 mmol/L.

Both vasopressor requirement and lactate >2 mmol/L must be present after adequate volume resuscitation. This phenotype carries hospital mortality exceeding approximately 40% in the original Sepsis-3 data. (JAMA Network)

Important terminology trap

“Severe sepsis”

This term is no longer used in Sepsis-3 because sepsis itself now requires organ dysfunction.

Older classification:

  • Infection

  • SIRS

  • Sepsis = infection plus SIRS

  • Severe sepsis = sepsis plus organ dysfunction

  • Septic shock = severe sepsis with persistent hypotension

Current classification:

  • Infection without organ dysfunction

  • Sepsis

  • Septic shock

“Septicaemia”

This is imprecise and should generally be avoided. Sepsis does not require demonstrable organisms in the bloodstream, and blood cultures may be negative.


2. SIRS, qSOFA and SOFA

SIRS criteria

Two or more of:

ParameterAbnormality
Temperature>38°C or <36°C
Heart rate>90/min
Respiratory rate>20/min or PaCO₂ <32 mmHg
WBC>12,000/mm³, <4,000/mm³ or >10% immature forms

SIRS is sensitive but nonspecific. Trauma, burns, pancreatitis, surgery, haemorrhage and pulmonary embolism can all produce SIRS without infection. Conversely, some septic patients do not satisfy two SIRS criteria. (JAMA Network)

qSOFA

One point each for:

  • Respiratory rate ≥22/min

  • Altered mentation

  • Systolic BP ≤100 mmHg

Mnemonic: RAS

A score ≥2 identifies a patient with suspected infection at increased risk of deterioration, but:

  • qSOFA does not define sepsis.

  • qSOFA does not exclude sepsis when negative.

  • It should trigger investigation, escalation and assessment of organ dysfunction.

  • The 2026 guideline recommends NEWS/NEWS2, MEWS or SIRS rather than qSOFA as the sole hospital screening tool. (JAMA Network)

SOFA score

Six organ systems are assessed.

SystemMain variable
RespiratoryPaO₂/FiO₂ ratio and respiratory support
CoagulationPlatelet count
LiverBilirubin
CardiovascularMAP and vasopressor requirement
CNSGlasgow Coma Scale
RenalCreatinine or urine output

High-yield SOFA thresholds

Score01234
PaO₂/FiO₂≥400<400<300<200 with support<100 with support
Platelets ×10³/µL≥150<150<100<50<20
Bilirubin mg/dL<1.21.2–1.92–5.96–11.9>12
CardiovascularMAP ≥70MAP <70Dopamine <5 or dobutamineDopamine 5.1–15 or noradrenaline/adrenaline ≤0.1Dopamine >15 or noradrenaline/adrenaline >0.1
GCS1513–1410–126–9<6
Creatinine mg/dL<1.21.2–1.92–3.43.5–4.9>5
Urine output<500 mL/day<200 mL/day

A rise of ≥2 from baseline in the context of infection operationalises sepsis. (JAMA Network)


3. Pathophysiology

Sepsis is not simply “infection spreading through the blood.” It is a failure of regulated host defence.

Sequence

1. Recognition of infection and tissue injury

Microbial structures—pathogen-associated molecular patterns—and molecules released from injured cells—damage-associated molecular patterns—activate pattern-recognition receptors such as Toll-like receptors.

2. Dysregulated inflammatory response

Inflammatory mediators include:

  • TNF-α

  • IL-1

  • IL-6

  • Complement products

  • Prostaglandins

  • Leukotrienes

  • Platelet-activating factor

  • Reactive oxygen species

The inflammatory response becomes widespread rather than remaining locally protective.

3. Endothelial and glycocalyx injury

This causes:

  • Increased vascular permeability

  • Capillary leak

  • Interstitial oedema

  • Loss of vascular tone

  • Abnormal leukocyte-endothelial interaction

  • Disordered microvascular blood flow

4. Vasodilatation

Inducible nitric oxide synthase increases nitric oxide production, producing profound vasodilatation and reduced systemic vascular resistance.

5. Relative and absolute hypovolaemia

  • Relative hypovolaemia: vascular capacity increases because of vasodilatation.

  • Absolute intravascular volume loss: fluid moves into the interstitium through leaky capillaries.

  • Additional loss may occur from vomiting, diarrhoea, fever, poor intake, drains or third spacing.

6. Coagulation activation

Tissue-factor pathways are activated while natural anticoagulant systems such as protein C and antithrombin are impaired. Fibrinolysis is suppressed.

Consequences:

  • Microvascular thrombosis

  • Organ ischaemia

  • Consumption of platelets and clotting factors

  • Disseminated intravascular coagulation

7. Cellular and mitochondrial dysfunction

Even when global oxygen delivery appears adequate, cells may not extract or use oxygen normally. Microcirculatory shunting and mitochondrial dysfunction contribute to organ failure.

8. Myocardial dysfunction

Sepsis may produce reversible depression of:

  • Left ventricular systolic function

  • Right ventricular function

  • Diastolic function

Cardiac output may therefore become inadequate despite severe vasodilatation.

9. Immunosuppression

Sepsis can progress from hyperinflammation to immune exhaustion or “immunoparalysis,” with lymphocyte apoptosis and impaired antigen presentation. This contributes to secondary and opportunistic infections.

Sepsis-3 emphasises that the key abnormality is a dysregulated, non-homeostatic host response causing organ injury. (JAMA Network)


4. Haemodynamic pattern

Early “warm” septic shock

Typical findings:

  • Reduced systemic vascular resistance

  • Normal or increased cardiac output

  • Warm peripheries

  • Bounding pulse

  • Wide pulse pressure

  • Tachycardia

  • Rapid capillary refill may occur early

  • Hypotension

Later or “cold” phenotype

May result from hypovolaemia, myocardial depression or advanced shock:

  • Reduced cardiac output

  • Cold, mottled peripheries

  • Weak pulse

  • Narrow pulse pressure

  • Delayed capillary refill

  • Oliguria

  • Altered consciousness

Do not assume every patient with septic shock will be warm.


5. Common sources of surgical sepsis

Intra-abdominal

  • Perforated peptic ulcer

  • Perforated appendix

  • Anastomotic leak

  • Colonic perforation

  • Ischaemic or gangrenous bowel

  • Perforated diverticulitis

  • Intra-abdominal or pelvic abscess

  • Infected pancreatic necrosis

  • Ascending cholangitis

  • Acute cholecystitis with perforation/empyema

  • Secondary peritonitis

  • Tertiary peritonitis

Urinary

  • Infected obstructed ureter

  • Pyonephrosis

  • Complicated pyelonephritis

  • Catheter-associated infection

  • Prostatic abscess

An infected obstructed urinary system requires urgent decompression, not antibiotics alone.

Skin and soft tissue

  • Necrotising fasciitis

  • Gas gangrene

  • Infected diabetic foot

  • Deep surgical-site infection

  • Infected pressure ulcer

  • Fournier gangrene

Thoracic

  • Pneumonia

  • Aspiration pneumonia

  • Empyema

  • Lung abscess

  • Mediastinitis

  • Oesophageal perforation

Device-associated

  • Central venous catheter

  • Urinary catheter

  • Vascular graft

  • Prosthetic joint

  • Cardiac device

  • Infected drain or stent

Postoperative clues

Think particularly of:

  • Anastomotic leak

  • Missed bowel injury

  • Infected haematoma

  • Intra-abdominal collection

  • Bile leak

  • Urinary leak

  • Wound infection

  • Line infection

  • Pneumonia

  • UTI

  • Acalculous cholecystitis

  • Bowel ischaemia

  • Clostridioides difficile infection


6. Risk factors for severe sepsis

  • Extremes of age

  • Diabetes mellitus

  • Chronic kidney or liver disease

  • Malignancy

  • Immunosuppressive medication

  • Neutropenia

  • HIV/AIDS

  • Malnutrition

  • Recent surgery or trauma

  • Prolonged hospitalisation

  • Previous broad-spectrum antibiotics

  • Indwelling lines, drains or catheters

  • Mechanical ventilation

  • Recent colonisation or infection with resistant organisms

  • Poor source control

  • Delayed antibiotic therapy

  • Splenectomy or functional asplenia


7. Clinical presentation

General

  • Fever or hypothermia

  • Rigors

  • Malaise

  • Confusion

  • Reduced mobility

  • Poor oral intake

  • Hyperglycaemia, including in non-diabetic patients

Older, immunocompromised and severely septic patients may be hypothermic rather than febrile.

Respiratory

  • Tachypnoea is often an early sign

  • Hypoxaemia

  • Respiratory alkalosis early

  • Metabolic acidosis with respiratory compensation later

  • ARDS

Cardiovascular

  • Tachycardia

  • Hypotension

  • Warm peripheries initially

  • Mottling or cold extremities later

  • Reduced pulse pressure in low-output shock

  • Arrhythmias, particularly atrial fibrillation

  • Elevated troponin from demand injury or septic cardiomyopathy

Neurological

  • Anxiety or agitation

  • Delirium

  • Confusion

  • Reduced GCS

  • Coma

Renal

  • Oliguria: <0.5 mL/kg/hour

  • Rising creatinine

  • Acute tubular injury

  • Fluid overload

  • Electrolyte and acid-base disturbance

Gastrointestinal and hepatic

  • Ileus

  • Feed intolerance

  • Stress-related mucosal bleeding

  • Cholestasis

  • Rising bilirubin and transaminases

  • Hypoglycaemia in severe hepatic dysfunction

Haematological

  • Thrombocytopenia

  • Prolonged PT/APTT

  • Low fibrinogen in advanced DIC

  • Elevated D-dimer

  • Anaemia

  • Leukocytosis or leukopenia

Skin/perfusion

  • Prolonged capillary refill

  • Mottling

  • Cool extremities

  • Cyanosis

  • Peripheral oedema from capillary leak


8. Lactate: a major examination topic

Why lactate rises

Elevated lactate may result from:

  • Inadequate oxygen delivery

  • Microcirculatory failure

  • Accelerated aerobic glycolysis driven by catecholamines

  • Mitochondrial dysfunction

  • Reduced hepatic clearance

  • Reduced renal clearance

  • Seizures

  • β₂-agonists or adrenaline

  • Severe liver disease

Therefore:

Elevated lactate does not automatically mean anaerobic metabolism, and normal lactate does not exclude sepsis.

Interpretation

  • 2 mmol/L: abnormal and relevant to septic-shock definition when associated with vasopressor dependence.

  • ≥4 mmol/L: severe hyperlactataemia and traditionally used as a trigger for aggressive resuscitation.

  • Serial trend is more useful than a single value.

Lactate should be interpreted with:

  • Blood pressure

  • Capillary refill

  • Mental status

  • Urine output

  • Skin temperature and mottling

  • Acid-base state

  • Liver function

  • Vasopressor treatment

Current guidance supports serial lactate measurements but warns against blindly continuing fluids until lactate normalises. (Society of Critical Care Medicine (SCCM))


9. Investigations

Investigations should occur concurrently with treatment.

Immediate bedside assessment

  • Full A–E assessment

  • Continuous ECG

  • SpO₂

  • Non-invasive BP at short intervals

  • Temperature

  • Capillary refill

  • Mental status/GCS

  • Hourly urine output

  • Fluid balance

  • Blood glucose

  • Examine wounds, drains, lines and catheters

Blood tests

  • Full blood count

  • Urea, creatinine and electrolytes

  • Liver profile and bilirubin

  • CRP

  • Arterial or venous blood gas

  • Lactate

  • Glucose

  • PT/INR, APTT

  • Fibrinogen and D-dimer if DIC suspected

  • Calcium, magnesium and phosphate

  • Group and save/crossmatch

  • Troponin/BNP where cardiac dysfunction is suspected

  • Peripheral blood film where indicated

Microbiology

Obtain cultures as soon as possible and ideally before antimicrobials, provided this does not cause a clinically important delay.

Usually obtain:

  • Two sets of blood cultures from separate peripheral sites

  • Cultures from a central line if line infection is suspected

  • Urine culture

  • Sputum or tracheal aspirate

  • Wound or pus specimen

  • Drain fluid

  • Bile or peritoneal fluid

  • CSF when indicated and safe

  • Relevant viral testing

Sepsis remains a clinical diagnosis; no single biomarker rules it in or rules it out. (Society of Critical Care Medicine (SCCM))

Imaging

Based on likely source:

  • Chest radiograph

  • Bedside lung ultrasound

  • Abdominal ultrasound

  • CT chest/abdomen/pelvis

  • CT with IV contrast when required for source detection

  • Echocardiography

  • Doppler studies

  • MR imaging in selected spinal, neurological or deep soft-tissue infection

Do not allow nonessential imaging to delay life-saving source control.

Procalcitonin

  • Do not use procalcitonin alone to decide whether to start antibiotics.

  • It may assist, together with clinical assessment, when deciding when to stop antibiotics if duration is uncertain and source control is adequate. (Society of Critical Care Medicine (SCCM))


10. Immediate management

Initial mental framework: “Sepsis Six plus source control”

Within the first assessment period:

  1. Give appropriate oxygen/respiratory support.

  2. Obtain IV access and cultures.

  3. Measure lactate and essential blood tests.

  4. Give appropriate IV antibiotics.

  5. Begin crystalloid resuscitation.

  6. Monitor urine output.

  7. Identify and control the source.

  8. Start vasopressors early when needed.


11. A–E approach

A: Airway

  • Assess patency.

  • Look for reduced consciousness, vomitus, secretions or airway oedema.

  • Use airway adjuncts as necessary.

  • Intubate when airway protection, oxygenation, ventilation or work of breathing cannot be maintained.

Be cautious during induction: critically ill septic patients can develop profound cardiovascular collapse due to vasodilatation, hypovolaemia and myocardial depression.

B: Breathing

  • Give oxygen for hypoxaemia.

  • Obtain ABG where appropriate.

  • Look for pneumonia, aspiration, pulmonary oedema and ARDS.

  • Use high-flow nasal oxygen in appropriate acute hypoxaemic respiratory failure.

  • Do not delay intubation when non-invasive support is failing.

The 2026 guideline describes typical oxygen targets across studies ranging approximately from 90–93% for conservative strategies to ≥96% for liberal strategies and recommends individualisation. (Society of Critical Care Medicine (SCCM))

C: Circulation

  • Two large-bore IV cannulae.

  • Take cultures and blood samples.

  • Start crystalloid.

  • Assess response dynamically.

  • Begin noradrenaline early if hypotension is severe or persists.

  • Insert arterial line when appropriate.

  • Central access should be obtained but should not delay vasopressor initiation.

  • Insert urinary catheter for hourly output where indicated.

D: Disability

  • GCS

  • Pupils

  • Blood glucose

  • Delirium assessment

  • Correct hypoglycaemia

  • Consider meningitis, intracranial infection or metabolic encephalopathy

E: Exposure

  • Examine the entire patient.

  • Inspect operation sites, perineum, back, pressure areas, drains and lines.

  • Look for cellulitis, crepitus, bullae, skin necrosis and disproportionate pain.

  • Assess abdomen and rectum where indicated.


12. Fluid resuscitation

Initial fluid

For sepsis-induced hypoperfusion or septic shock, the 2026 guideline suggests at least 30 mL/kg of IV crystalloid during the first three hours, with frequent reassessment and individualisation.

In unstable shock, vasopressors may need to be started concurrently rather than waiting for completion of the fluid volume. (Society of Critical Care Medicine (SCCM))

Which fluid?

First line

Crystalloid

Preferred

Balanced crystalloid, such as Ringer’s lactate or Plasma-Lyte, rather than 0.9% saline for most patients.

Exception: 0.9% saline may be preferred in sepsis with traumatic brain injury. (Society of Critical Care Medicine (SCCM))

Avoid

  • Hydroxyethyl starch: should not be used.

  • Gelatin: generally discouraged.

  • Routine albumin supplementation: not normally needed.

Albumin may occasionally be considered after very large crystalloid volumes or in selected patients with cirrhosis, but it is not first-line resuscitation fluid. (Society of Critical Care Medicine (SCCM))

Do not give 30 mL/kg blindly

Adjust the rate and aliquot size in:

  • Heart failure

  • Severe renal impairment

  • Pulmonary oedema

  • Frailty

  • Cirrhosis

  • Right ventricular failure

  • Significant valvular disease

A practical method is to give 250–500 mL aliquots and reassess, although profoundly unstable patients may require faster resuscitation.

Assessing fluid responsiveness

Preferred dynamic methods:

  • Passive leg raise with change in stroke volume/cardiac output

  • Stroke-volume response to a fluid bolus

  • Pulse-pressure variation

  • Stroke-volume variation

  • Bedside echocardiography

  • Change in end-tidal CO₂ in ventilated patients in selected settings

Static measurements such as CVP alone are poor predictors of fluid responsiveness.

Targets of resuscitation

Look for combined improvement in:

  • MAP

  • Mental status

  • Capillary refill

  • Mottling

  • Peripheral temperature

  • Urine output

  • Lactate trend

  • Respiratory status

  • Stroke volume/cardiac output where measured

Current guidance supports dynamic assessment, serial lactate and capillary refill as an adjunct rather than repeatedly administering fluid based on a single static parameter. (Society of Critical Care Medicine (SCCM))

Signs of fluid overload

  • Rising oxygen requirement

  • New crackles/B-lines

  • Pulmonary oedema

  • Raised JVP

  • Worsening peripheral oedema

  • Increasing intra-abdominal pressure

  • Hepatic congestion

  • Failure of stroke volume to increase after bolus

After stabilisation, active deresuscitation with diuretics or ultrafiltration may be considered when fluid accumulation is harmful. (Society of Critical Care Medicine (SCCM))


13. Vasopressors

When to start

Start when:

  • Hypotension persists despite initial fluid resuscitation, or

  • Shock is so unstable that waiting for completion of fluids would be dangerous.

Peripheral initiation through a good proximal cannula is preferable to delaying treatment while waiting for a central line. Inspect the site frequently and transfer to central access when practical. (Society of Critical Care Medicine (SCCM))

MAP target

  • Initial target: 65 mmHg

  • In adults ≥65 years, the 2026 guideline suggests an initial range of 60–65 mmHg.

  • Individualise upward in selected chronic hypertensive patients if renal, cerebral or coronary perfusion appears inadequate. (Society of Critical Care Medicine (SCCM))

First-line: noradrenaline

Noradrenaline is preferred because it raises vascular tone effectively with less tachyarrhythmia than dopamine.

Typical starting range in practice:

  • Approximately 0.02–0.05 micrograms/kg/min

  • Titrate rapidly according to MAP and perfusion

Exact preparation and dosing must follow local ICU protocols.

Second agent: vasopressin

Add vasopressin when noradrenaline requirement is escalating.

Typical practical dose:

  • 0.03 units/min as a fixed infusion

  • Usually not titrated like noradrenaline

It reduces catecholamine requirement but is not normally the initial sole vasopressor.

Third agent: adrenaline

Add adrenaline if MAP remains inadequate despite noradrenaline and vasopressin.

Important adverse effects:

  • Tachycardia

  • Arrhythmias

  • Hyperglycaemia

  • Increased lactate from β₂-mediated glycolysis

An adrenaline-associated lactate rise does not always indicate worsening tissue hypoxia.

Dopamine

Not routine.

Problems include:

  • Tachyarrhythmias

  • Increased myocardial oxygen consumption

  • Less predictable haemodynamic response

It may occasionally be considered in selected patients with significant bradyarrhythmia and low arrhythmia risk.

Vasopressor sequence

Noradrenaline → add vasopressin → add adrenaline

This is the main examination sequence. (Society of Critical Care Medicine (SCCM))


14. Inotropes and septic cardiomyopathy

Suspect cardiac dysfunction when there is persistent hypoperfusion despite:

  • Adequate intravascular volume

  • Adequate MAP

  • Noradrenaline treatment

Clues include:

  • Low cardiac output on echocardiography

  • Reduced ventricular function

  • Cool peripheries

  • Persistent oliguria

  • Rising lactate

  • Low central venous oxygen saturation in the appropriate context

Options:

  • Add dobutamine to noradrenaline, or

  • Use adrenaline as a combined vasopressor/inotrope.

Dobutamine may cause hypotension because of vasodilatation and may provoke tachyarrhythmias. Do not use an inotrope instead of the vasopressor required to maintain arterial pressure. (Society of Critical Care Medicine (SCCM))


15. Antibiotic therapy

Timing — current 2026 approach

Septic shock

Administer immediately, ideally within one hour of recognition.

Probable or definite sepsis without shock

Administer immediately, ideally within one hour.

Possible sepsis without shock

Perform a rapid, time-limited diagnostic assessment. If infection remains a concern, give antimicrobials within three hours from first suspicion.

Low likelihood of infection, no shock

Antibiotics may be deferred with close monitoring and continued investigation. (Society of Critical Care Medicine (SCCM))

Before antibiotics

  • Obtain blood cultures and relevant specimens ideally first.

  • Do not create a dangerous delay merely to obtain cultures.

Empirical selection should consider

  • Likely anatomical source

  • Community- or hospital-acquired infection

  • Local antibiogram

  • Previous culture results

  • Prior antibiotics

  • Duration of hospitalisation

  • Previous resistant-organism colonisation

  • Immunosuppression

  • Renal and hepatic function

  • Drug allergy

  • Presence of foreign material

  • Severity of illness

Typical surgical principles

Community-acquired intra-abdominal sepsis

Cover:

  • Enteric Gram-negative organisms

  • Streptococci

  • Anaerobes

Hospital-acquired intra-abdominal sepsis

May require broader cover for:

  • Resistant Enterobacterales

  • Pseudomonas

  • Enterococcus in selected patients

  • MRSA when risk factors exist

  • Candida in selected high-risk patients

Necrotising soft-tissue infection

Requires:

  • Broad Gram-positive, Gram-negative and anaerobic cover

  • MRSA cover where relevant

  • A toxin-suppressing agent such as clindamycin when streptococcal or clostridial disease is suspected

  • Immediate surgery

Specific drug choices must follow local Sri Lankan or institutional antimicrobial policy because resistance patterns differ substantially.

Double Gram-negative coverage

Do not use routinely.

Consider two active agents initially only when there is a high risk of resistant Gram-negative infection or a very high risk of death before sensitivities become available.

Empirical antifungal therapy

Not routine.

Consider it individually in patients with factors such as:

  • Significant immunosuppression

  • Prolonged broad-spectrum antibiotics

  • Long hospitalisation

  • Recurrent gastrointestinal perforation

  • Anastomotic leak

  • Necrotising pancreatitis

  • Multifocal Candida colonisation

  • Total parenteral nutrition

  • Intra-abdominal source with clinical deterioration

The 2026 guideline generally suggests against routine empiric antifungal treatment but recognises selected high-risk exceptions. (Society of Critical Care Medicine (SCCM))

Administration principles

  • Give a full loading dose.

  • Do not reduce the initial loading dose merely because of renal failure; adjust maintenance dosing.

  • Prolonged or extended infusion of β-lactams after a loading dose is recommended where operationally feasible.

  • Review microbiology daily.

  • Narrow or stop therapy when appropriate.

  • Use the shortest effective duration following adequate source control. (Society of Critical Care Medicine (SCCM))


16. Source control

For a surgeon, this is often the decisive treatment.

Methods

  • Drain an abscess

  • Debride necrotic or infected tissue

  • Resect gangrenous bowel

  • Repair or resect a perforated viscus

  • Control an anastomotic leak

  • Decompress an obstructed infected urinary system

  • Drain an empyema

  • Decompress an obstructed biliary system

  • Remove an infected line

  • Remove infected foreign material when required

  • Amputate a non-salvageable septic limb

  • Perform washout and drainage where indicated

Timing

Anatomical diagnoses requiring source control should be identified rapidly. Current guidance suggests early source control, ideally within six hours of diagnosing sepsis or septic shock requiring source control. (Society of Critical Care Medicine (SCCM))

Operative principle in the unstable patient

Use the least physiologically stressful procedure that reliably controls contamination.

Examples:

  • Damage-control laparotomy rather than prolonged definitive reconstruction

  • Drainage rather than major resection where appropriate

  • Temporary abdominal closure

  • Stoma rather than high-risk anastomosis

  • Percutaneous drainage in selected collections

  • Nephrostomy or ureteric stent for infected obstruction

  • ERCP or biliary drainage for cholangitis

Do not delay essential source control while trying to normalise every laboratory abnormality.

Necrotising fasciitis

Immediate radical debridement is required when suspected. Antibiotics and imaging must not delay theatre when the clinical diagnosis is clear.

Features include:

  • Pain out of proportion

  • Rapid progression

  • Skin anaesthesia

  • Bullae

  • Dusky skin

  • Crepitus

  • Systemic toxicity

  • Haemorrhagic blistering

  • “Dishwater” fluid at operation

  • Necrotic fascia with easy finger dissection

Repeat debridement is frequently necessary.


17. Corticosteroids

The 2026 guideline suggests IV corticosteroids for adults with septic shock. In practice, they are particularly relevant when hypotension persists and there is an ongoing vasopressor requirement despite fluids and vasopressors. (Society of Critical Care Medicine (SCCM))

Standard examination regimen

Hydrocortisone 200 mg/day IV, either:

  • 50 mg every six hours, or

  • Continuous infusion

This is not the same as high-dose pulse steroid therapy. (Springer Nature Link)

Key points

  • Do not routinely use steroids for sepsis without shock.

  • Do not use very high-dose, short-course steroids for septic shock.

  • ACTH stimulation testing is not routinely required to decide treatment.

  • Benefits are mainly faster shock reversal; mortality effect is less certain.

  • Monitor glucose, sodium, infection risk, delirium and muscle weakness.


18. Sodium bicarbonate

Generally avoid

Do not give bicarbonate merely to correct lactic acidosis or reduce vasopressor requirement in septic shock.

Potential problems:

  • CO₂ generation

  • Intracellular acidosis

  • Hypernatraemia

  • Volume overload

  • Reduced ionised calcium

  • Left shift of the oxygen dissociation curve

  • Overshoot alkalosis

When it may be considered

Current guidance suggests bicarbonate in septic shock with:

  • Severe metabolic acidaemia, pH ≤7.2, and

  • Moderate-to-severe AKI, approximately AKIN stage 2 or 3.

Treat the cause—perfusion failure and infection—rather than chasing the bicarbonate value. (Society of Critical Care Medicine (SCCM))


19. Respiratory support and ARDS

Indications for intubation

  • Refractory hypoxaemia

  • Exhaustion

  • Severe work of breathing

  • Reduced consciousness

  • Inability to protect the airway

  • Severe acidosis with inadequate respiratory compensation

  • Haemodynamic instability where controlled ventilation is required

ARDS ventilation

  • Tidal volume: approximately 6 mL/kg predicted/ideal body weight

  • Plateau pressure: ≤30 cmH₂O

  • Appropriate PEEP

  • Prone ventilation for moderate-to-severe ARDS, generally >12 hours/day

  • Conservative fluid strategy after shock has stabilised

  • Consider venovenous ECMO for selected severe refractory cases in experienced centres

Tidal volume is based on height and sex—not actual body weight. (Society of Critical Care Medicine (SCCM))


20. Renal support

AKI management

  • Restore perfusion

  • Avoid nephrotoxins

  • Review antibiotic doses

  • Correct severe electrolyte abnormalities

  • Monitor fluid balance

  • Exclude obstruction

  • Avoid repeated non-beneficial fluid loading

Indications for renal replacement therapy

Remember AEIOU:

  • Acidosis refractory to medical management

  • Electrolyte abnormality, especially refractory hyperkalaemia

  • Intoxication with dialysable toxin

  • Overload refractory to diuretics

  • Uraemic complications

Do not start RRT solely because creatinine is elevated if no definitive indication exists. Either continuous or intermittent therapy may be used when RRT is indicated; CRRT is often easier haemodynamically in unstable shock. (Society of Critical Care Medicine (SCCM))


21. Blood products and coagulation

Red cells

Use a restrictive transfusion strategy in most patients.

A common examination threshold is:

  • Transfuse at Hb approximately <7 g/dL in a stable non-bleeding patient.

Do not use a rigid threshold when there is:

  • Active major bleeding

  • Myocardial ischaemia

  • Severe hypoxaemia

  • Ongoing haemodynamic instability

  • Inadequate oxygen delivery despite other measures

The 2026 guideline recommends restrictive rather than liberal transfusion. (Society of Critical Care Medicine (SCCM))

Platelets

Transfusion is generally based on bleeding risk, procedure and count rather than sepsis alone.

Common practical thresholds:

  • <10 ×10⁹/L without bleeding

  • <20 ×10⁹/L when significant bleeding risk exists

  • <50 ×10⁹/L for active bleeding or most invasive procedures

  • Higher thresholds for neurosurgical or selected critical-site procedures

DIC management

  • Treat sepsis and achieve source control.

  • Give platelets, FFP or cryoprecipitate primarily for bleeding or an invasive procedure.

  • Do not try to normalise every coagulation result in a non-bleeding patient.

  • Maintain adequate fibrinogen during significant bleeding.


22. Glucose, nutrition and prophylaxis

Glucose

Start insulin therapy when glucose is persistently ≥180 mg/dL or 10 mmol/L.

Avoid tight normoglycaemic control because hypoglycaemia is dangerous. (Society of Critical Care Medicine (SCCM))

Nutrition

  • Start enteral feeding early once haemodynamic stability permits.

  • The 2026 recommendation supports enteral nutrition within 72 hours.

  • Avoid full feeding during uncontrolled shock or escalating vasopressor requirement.

  • Increase progressively according to tolerance. (Society of Critical Care Medicine (SCCM))

VTE prophylaxis

  • Pharmacological prophylaxis unless contraindicated.

  • LMWH is preferred over unfractionated heparin for most patients.

  • Use mechanical prophylaxis when anticoagulation is contraindicated. (Society of Critical Care Medicine (SCCM))

Stress-ulcer prophylaxis

Use in patients with significant GI bleeding risk, such as:

  • Mechanical ventilation

  • Coagulopathy

  • Previous ulcer/GI bleeding

  • Severe burns

  • Traumatic brain injury

  • Multiple major risk factors

Do not prescribe automatically to every septic patient. (Society of Critical Care Medicine (SCCM))


23. Treatments not recommended routinely

Do not routinely use:

  • IV vitamin C

  • IV immunoglobulin

  • Vitamin D as sepsis treatment

  • High-volume haemofiltration for “cytokine removal”

  • Polymyxin-B haemoperfusion

  • Plasma exchange solely for ordinary sepsis

  • High-dose steroids

  • Hydroxyethyl starch

  • Routine dopamine

  • Routine empiric antifungal treatment

  • Routine bicarbonate for lactic acidosis

  • Routine antipyretics solely to improve survival

  • Probiotics as a sepsis treatment

  • β-blockers as routine septic-shock treatment

The 2026 guideline specifically advises against several unproven adjunctive therapies, including IV vitamin C, IVIG and blood purification techniques. (Society of Critical Care Medicine (SCCM))


24. Monitoring response

Continuous or frequent

  • Heart rate and rhythm

  • MAP

  • SpO₂

  • Respiratory rate

  • Temperature

  • GCS

  • Urine output

  • Peripheral perfusion

  • Vasopressor dose

  • Fluid balance

Serial

  • Lactate

  • ABG

  • Creatinine and electrolytes

  • Glucose

  • Platelets

  • Coagulation

  • Bilirubin/LFT

  • Haemoglobin

  • CRP or procalcitonin where clinically useful

Signs of improvement

  • Reduced vasopressor requirement

  • Improving mentation

  • Normalising capillary refill

  • Warmer peripheries

  • Urine output >0.5 mL/kg/hour

  • Falling lactate

  • Improved acid-base state

  • Improved oxygenation

  • Source controlled

Persistent shock: reassess the diagnosis

Consider:

  • Ongoing uncontrolled infection

  • Missed abscess or leak

  • Inadequate antimicrobial cover

  • Resistant organism

  • Inadequate intravascular volume

  • Fluid overload with cardiac dysfunction

  • Septic cardiomyopathy

  • Haemorrhage

  • Pulmonary embolism

  • Tension pneumothorax

  • Cardiac tamponade

  • Abdominal compartment syndrome

  • Adrenal insufficiency

  • Anaphylaxis

  • Mesenteric ischaemia

  • Drug-induced vasodilatation


25. Complications

  • ARDS

  • AKI

  • DIC

  • Septic cardiomyopathy

  • Atrial fibrillation and other arrhythmias

  • Acute liver dysfunction

  • Encephalopathy and delirium

  • Critical illness polyneuropathy/myopathy

  • Stress ulceration

  • Ileus

  • Acalculous cholecystitis

  • Pressure injury

  • Limb ischaemia from shock/vasopressors

  • Secondary nosocomial infection

  • Malnutrition

  • Venous thromboembolism

  • Post-intensive-care syndrome

  • Cognitive, psychological and functional impairment


26. Traditional Hour-1 bundle — know for examinations

The commonly taught SSC Hour-1 bundle is:

  1. Measure lactate; remeasure if initially elevated.

  2. Obtain blood cultures before antibiotics.

  3. Give broad-spectrum antibiotics.

  4. Give 30 mL/kg crystalloid for hypotension or severe hyperlactataemia.

  5. Start vasopressors if hypotension persists to maintain MAP ≥65 mmHg.

For modern answers, add the nuances:

  • The 30 mL/kg volume is delivered during the initial three hours with individualisation and reassessment.

  • Antibiotic timing depends on shock and the certainty of infection.

  • Possible sepsis without shock permits rapid investigation, but shock requires immediate treatment.

  • Do not continue fluids simply until lactate normalises.

  • Source control is a central component, ideally within six hours where required. (Society of Critical Care Medicine (SCCM))


27. Common MCQ traps

Trap 1

“SIRS is necessary for sepsis.”

False. SIRS may be absent.

Trap 2

“qSOFA ≥2 defines sepsis.”

False. It is a risk prompt, not the diagnostic definition.

Trap 3

“Severe sepsis is the current term for sepsis with organ dysfunction.”

False. The term has been removed from Sepsis-3.

Trap 4

“Septic shock is any infection with BP <90 mmHg.”

False. Current criteria require sepsis, vasopressors to maintain MAP ≥65 and lactate >2 mmol/L after adequate resuscitation.

Trap 5

“Negative blood cultures exclude sepsis.”

False.

Trap 6

“Normal lactate excludes septic shock.”

A normal lactate means the formal Sepsis-3 septic-shock criteria are not met, but severe infection with hypotension or organ dysfunction can still be present and requires urgent treatment.

Trap 7

“All septic patients must receive exactly 30 mL/kg regardless of response.”

False. Give early crystalloid but reassess and individualise.

Trap 8

“Normal saline is always the preferred fluid.”

False. Balanced crystalloids are preferred for most patients.

Trap 9

“Albumin is first-line.”

False. Crystalloid is first-line.

Trap 10

“Dopamine is the first vasopressor.”

False. Noradrenaline is first-line.

Trap 11

“Vasopressin replaces noradrenaline.”

Usually false. It is generally added to escalating noradrenaline.

Trap 12

“Dobutamine should be used for all hypotensive patients.”

False. Use it for cardiac dysfunction with persistent hypoperfusion despite adequate volume and pressure.

Trap 13

“Procalcitonin should determine whether antibiotics are started.”

False.

Trap 14

“Bicarbonate is routinely beneficial in septic lactic acidosis.”

False.

Trap 15

“Steroids are indicated in all sepsis.”

False. Their role is septic shock with vasopressor requirement.

Trap 16

“Antibiotics alone are sufficient for an abscess or perforation.”

False. Source control is essential.

Trap 17

“A postoperative CT should always precede treatment.”

False. Resuscitation and antibiotics must not be delayed, and obvious surgical catastrophes may require immediate theatre.


28. OSCE/viva answer

Scenario

A patient on postoperative day 5 after colorectal surgery has:

  • Temperature 39°C

  • HR 132/min

  • BP 82/48 mmHg

  • RR 30/min

  • Confusion

  • Urine output 10 mL/hour

  • Increasing abdominal pain

High-scoring response

“This patient has suspected septic shock, most likely from an anastomotic leak or intra-abdominal collection. I would call for senior surgical, anaesthetic and critical-care help and manage using an A–E approach. I would provide oxygen and assess the need for intubation, establish large-bore IV access, obtain blood cultures, lactate, blood gas, full blood count, renal and liver profiles, coagulation and crossmatch, and start source-appropriate broad-spectrum IV antibiotics immediately. I would begin balanced-crystalloid resuscitation with repeated assessment of perfusion and fluid responsiveness. If hypotension is severe or persists, I would start noradrenaline early, initially peripherally if necessary, targeting a MAP around 65 mmHg. I would catheterise the patient and monitor hourly urine output. I would urgently evaluate the abdomen, wound and drains, arrange appropriate imaging if this does not delay treatment, and achieve source control—likely drainage, re-laparotomy or damage-control surgery—as soon as possible.”

This answer scores because it includes:

  • Recognition

  • Escalation

  • A–E

  • Cultures and lactate

  • Antibiotics

  • Balanced crystalloid

  • Early noradrenaline

  • Monitoring

  • Probable source

  • Urgent source control


29. Final memory framework

The seven pillars

R-A-F-T-S-O-M

  1. R — Recognition

    • Infection plus organ dysfunction

    • SOFA rise ≥2

  2. A — Antibiotics

    • Immediately in shock

    • Cultures first if no delay

  3. F — Fluids

    • Balanced crystalloid

    • Approximately 30 mL/kg in first three hours

    • Reassess dynamically

  4. T — Tone

    • Noradrenaline first

    • MAP approximately 65

  5. S — Source control

    • Drain, debride, decompress, remove or resect

    • Ideally within six hours when required

  6. O — Organ support

    • Ventilation, RRT, glucose, nutrition, blood products

  7. M — Monitoring

    • Lactate trend, urine output, capillary refill, mental state, MAP and fluid balance

One-line examination answer

Sepsis is infection-associated life-threatening organ dysfunction; septic shock is sepsis requiring vasopressors to maintain MAP ≥65 mmHg with lactate >2 mmol/L despite adequate fluid resuscitation. Management is immediate recognition, cultures and lactate, source-directed antibiotics, balanced-crystalloid resuscitation, early noradrenaline, urgent source control and appropriate organ support.

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