MAP 58 with cold mottled legs and a lactate of 5 — cold & wet, warm & dry, or obstructed? Pick the right pressor for the physiology.
ABCDE
High-flow O₂; 2 large-bore IVs or central access; bedside echo/POCUS to classify; noradrenaline is the default pressor; treat the underlying cause.
Confirm shock: MAP <65 plus hypoperfusion — lactate >2, oliguria <0.5 mL/kg/h, altered mentation, mottling, delayed capillary refill
Classify at the bedside: cold & wet = cardiogenic (poor LV on echo), cold & dry = hypovolaemic, warm & bounding = distributive (sepsis/anaphylaxis), obstructive = tamponade/tension PTX/massive PE on POCUS
Default pressor: noradrenaline 0.05–1 mcg/kg/min to MAP 65 — start peripherally via a good proximal cannula while arranging central access; don't wait for a CVC
Cardiogenic: noradrenaline ± dobutamine 2.5–10 mcg/kg/min for low output; urgent reperfusion/cause-directed care; avoid fluid boluses
Obstructive: relieve the obstruction — pericardiocentesis (tamponade), needle decompression (tension PTX), thrombolysis (massive PE with shock)
Wean correctly: titrate down once MAP stable ≥65 and perfusion restored; wean noradrenaline before vasopressin; monitor lactate clearance and urine output
Order set
- Arterial line for beat-to-beat MAP
- Bedside echo + IVC + lung POCUS
- Noradrenaline infusion
- Central venous catheter (not a prerequisite to start)
- Serial lactate q2–4 h
- Catheter — strict hourly urine output
- Crossmatch if bleeding suspected
Monitor
- ContinuousInvasive MAP, HR, SpO₂
- q2–4 hLactate, capillary refill, mottling score
- HourlyUrine output — target ≥0.5 mL/kg/h
- DailyFluid balance, vasopressor dose trend, renal + liver function
Escalate / ICU
- Escalating pressor dose without a working diagnosis
- Lactate >4 or not clearing
- Signs of limb/gut ischaemia
- Need for mechanical support in cardiogenic shock — Impella CP reasonable (Class 2a) in selected STEMI cardiogenic shock (DanGer Shock, NEJM 2024); routine VA-ECMO has NO benefit (ECLS-SHOCK); IABP not routine (IABP-SHOCK II)
- Any shock not responding within the first hour — ICU review
Criteria
NoradrenalineFirst-line: sepsis, most shock — 0.05–1 mcg/kg/min
VasopressinAdd-on ≤0.03 U/min in refractory septic shock
AdrenalineAnaphylaxis; cold septic shock alternative
DobutamineInotrope for cardiogenic with low output — 2.5–10 mcg/kg/min
PhenylephrinePure α — only for tachyarrhythmia-limited or anaesthesia hypotension
Never
- Give dopamine first-line (arrhythmias, worse outcomes)
- Withhold pressors until central access — peripheral noradrenaline through a good IV is safe short-term
- Bolus fluids into cardiogenic or obstructive shock
Key
- MAP target is 65 — higher targets add arrhythmia, not survival
- Stage cardiogenic shock with SCAI SHOCK 2022 staging (A–E); angiotensin II (Giapreza) is a third-line catecholamine-sparing option (ATHOS-3)
- Bedside echo changes management in ~1/3 of undifferentiated shock
- The pressor buys time; only treating the cause saves the patient
Clinical detail — differentials, red flags, pitfalls, disposition
Red flags
- Lactate ≥4
- Cool mottled extremities
- SBP <90 with oliguria
- Syncope with chest pain (think PE/dissection/ACS)
Differentials
- Sepsis
- Acute MI / decompensated heart failure
- Massive PE, tamponade, tension pneumothorax
- Adrenal crisis, anaphylaxis, spinal shock
Common mistakes
- Assuming sepsis in every warm patient
- Chasing a MAP number while lactate climbs
- Starting dobutamine in hypotension without a pressor (it vasodilates)
- Missing obstruction — POCUS early
Disposition & follow-up
ICU for all vasopressor-dependent patients; review pressor dose and volume status every hour; identify and document the shock type within the first hour.
💊 Treatment detail — doses & preparation
Noradrenaline (norepinephrine)vasopressor
Dose0.05–1 mcg/kg/min IV infusion, titrate to MAP ≥65
Preparation4 mg in 250 mL D5W or NS (16 mcg/mL) via infusion pump; central line preferred — proximal peripheral vein acceptable short-term
MonitorContinuous invasive MAP; check limb perfusion, urine output; wean gradually, never stop abruptly
Vasopressinvasopressor
Dose0.03 U/min IV infusion (fixed, do not titrate)
Preparation20 U in 100 mL D5W (0.2 U/mL) via pump; add-on to noradrenaline
MonitorWatch for digital/mesenteric ischaemia and hyponatraemia
Adrenaline infusionvasopressor/inotrope
Dose0.05–1 mcg/kg/min IV infusion, titrate to effect
Preparation4 mg in 250 mL D5W/NS (16 mcg/mL) via pump; central access for prolonged use
MonitorTachycardia, arrhythmia, lactate rise; invasive MAP
Dobutamineinotrope
Dose2.5–10 mcg/kg/min IV infusion
Preparation250 mg in 250 mL D5W/NS (1 mg/mL) via pump; central line preferred
MonitorHR, arrhythmias, urine output; vasodilates — combine with noradrenaline if hypotensive
📖 Textbook Ch.1–6; Surviving Sepsis 2026; DanGer Shock 2024; SCAI SHOCK 2022Reviewed July 2026