Shock, Sepsis & Multisystem · Topic 2 of 16

Sepsis & Septic Shock

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Shock & resuscitation · sepsis

Sepsis & Septic Shock

Organ dysfunction from infection. Antibiotics within 1 hour, 30 mL/kg balanced crystalloid, norepinephrine to MAP 65 mmHg and early source control.

01 · First hourAntibiotics within 1 h of recognition

02 · Initial fluid30 mL/kg balanced crystalloid in 3 h

03 · First pressorNorepinephrine first, target MAP 65

Why it happens

Cardiac output is often high at first — warm shock

Cytokines dilate arterioles and shunt blood past capillaries

Mediators such as TNF and IL-1 also cause microthrombi. Poor capillary flow impairs oxygen delivery and causes organ dysfunction; cardiac output is initially high, then may fall.

Diagnosis: Sepsis-3

Sepsis is organ dysfunction from a dysregulated response to infection

Sepsis: infection plus an acute SOFA rise of ≥ 2 points

Septic shock: vasopressors needed to keep MAP ≥ 65 mmHg

Septic shock: lactate over 2 mmol/L despite adequate fluid

Sepsis-3 was defined with the original SOFA score; SOFA-2 (JAMA 2025) revises its thresholds and organ-support items — see the Multiple Organ Dysfunction Syndrome sheet. SIRS (≥ 2 of: temperature over 38 or under 36 °C, HR over 90, RR over 20 or PaCO₂ under 32 mmHg, WBC over 12,000, under 4,000 or over 10% bands) is nonspecific and no longer defines sepsis.

Screening

Screen with NEWS, NEWS2, MEWS or SIRS — not qSOFA alone

qSOFA (RR ≥ 22, altered mentation, SBP ≤ 100) flags death risk only

Possible sepsis, no shock: antibiotics within 3 h if concern persists

Low likelihood of infection: defer antibiotics and monitor

Red flags

Unstable shock: severe hypotension, mottling, cyanosis, altered mentation pressors with fluid

Hypotension persists after the initial crystalloid bolus start pressors

Lactate ≥ 4 mmol/L 30 mL/kg fluid

Abscess, obstructed biliary tract, necrotizing infection source control

Infected device remove it

Hydroxyethyl starch or gelatin don't give

IV vitamin C, or antipyretics to improve outcome don't give

Bicarbonate for lactic acidemia (unless pH ≤ 7.2 with AKI 2–3) don't give

Treatment

The clock starts at recognition — every bundle element begins in the first hour

Hour-1 bundle, then source control

Measure lactate, draw blood culturesremeasure lactate if over 2 mmol/L

→

IV antibiotics within 1 hourcultures first only if they cause no meaningful delay

→

30 mL/kg balanced crystalloid in 3 hfor hypotension or lactate ≥ 4 mmol/L

→

Norepinephrine for MAP under 65start peripherally — don't wait for central access

→

Source control, ideally within 6 hoursdrain, debride or remove the infected device

Antibioticsmatch spectrum to risk

Beta-lactam: load, then prolonged infusion

Empiric choice by source and local antibiogram

MRSA or resistant cover only at high risk; no routine antifungal or anaerobic cover

De-escalatenarrow and shorten

De-escalate on cultures — suggested even when cultures are negative

Stop for a noninfectious cause; procalcitonin plus judgment to stop

Fluidsbalanced crystalloid

Balanced crystalloid 30 mL/kg

Balanced over 0.9% saline; crystalloid alone suggested over adding albumin

BMI over 30: dose by adjusted or ideal weight · TBI: 0.9% saline

Reassessbefore more fluid

Passive leg raise, SV or pulse pressure variation, cap refill, serial lactate

Do not chase a normal lactate

Pressorsescalate in steps

Norepinephrine Vasopressin 0.03 units/min (fixed) Epinephrine

Norepinephrine to MAP 65 → add vasopressin → add epinephrine

Hold MAP within about 5 mmHg of target, not higher

Steroidsongoing pressor need

Hydrocortisone 50 mg IV q6h

Hydrocortisone 200 mg/day IV (bolus q6h or infusion)

SSC 2021: NE or epinephrine ≥ 0.25 mcg/kg/min for ≥ 4 h

Inotropeseptic cardiomyopathy

Dobutamine Epinephrine

Hypoperfusion despite volume and MAP: add dobutamine or use epinephrine

Inotropes supplement, never replace, vasopressors

ICU care and therapies to avoid

ICU within 6 hours when neededarterial line for intermediate-to-high or escalating pressor doses, multiple pressors or frequent sampling

Prophylaxis and nutritionLMWH over unfractionated heparin for VTE · PPI only with GI-bleeding risk factors · enteral nutrition within 72 h

Kidney replacement only for a definitive indicationcontinuous or intermittent modes are both acceptable

Refractory shock: insufficient evidence or suggested againstmethylene blue insufficient evidence · against terlipressin, esmolol or landiolol, IVIG, blood purification

Overall mortalityabout 25–30% for sepsis, 40–60% for septic shock; highest at the extremes of age. Separate from the over 10% and over 40% tied to the Sepsis-3 criteria

SSC 2026 suggests MAP 60–65 mmHg at age 65 or older, and now suggests (rather than recommends) norepinephrine over vasopressin or angiotensin II. Vasopressin: SSC 2021 started it at norepinephrine 0.25–0.5 mcg/kg/min; SSC 2026 says only "escalating doses". Steroids stay a conditional, low-certainty suggestion (Corticosteroids in Critical Illness sheet).

Supportive care

Restrictive transfusion: hemoglobin trigger about 7 g/dL

Start insulin when glucose is ≥ 180 mg/dL

Sepsis or septic shock?

	Sepsis	Septic shock
Definition	Infection plus acute SOFA rise ≥ 2	Sepsis needing vasopressors for MAP ≥ 65 mmHg
Lactate	May be normal or raised	Over 2 mmol/L despite adequate fluid
Hospital mortality (Sepsis-3)	Over 10%	Over 40%
Antibiotics	Within 1 h if probable or definite; within 3 h if only possible	Immediately — within 1 h, even if only possible

Pearl

The clock starts at recognition: cultures, lactate, antibiotics, fluid and pressors all begin in the first hour.

Sources · Surviving Sepsis Campaign adult guidelines (SCCM, 2026) · 2026 SCCM/ESICM Sepsis Guideline: key changes from 2021 (Guideline Central) · Surviving Sepsis Campaign Guidelines 2021 (Intensive Care Med) · Sepsis-3 definitions (JAMA 2016) · Sepsis and Septic Shock (Merck Manual Professional, 2026) · Surviving Sepsis Campaign Bundle: 2018 update (Intensive Care Med) · Hour-1 bundle summary (American Nurse) · Follow your institution's protocols.