Lactate is a marker of severity and response, not only of tissue hypoxia. Re-measure every 2 h during resuscitation; capillary refill time is a fast, non-inferior target. Know the non-hypoxic causes of raised lactate.
At the bedside
Timed steps- 1
Measure lactate
0 hArterial or venous; > 2 mmol/L is abnormal, > 4 mmol/L is high-risk.
- 2
Re-measure
Every 2 hAim for a falling lactate (≥ 10-20% drop in 2 h) while resuscitating. Do not keep giving fluid just to normalise lactate (SSC 2026).
- 3
Capillary refill time
Every 30 minPress the distal phalanx of the index finger with a glass slide for 10 s; normal ≤ 3 s. Normalising CRT was non-inferior to lactate-guided resuscitation (ANDROMEDA-SHOCK).
- 4
Look for non-hypoxic causes
If lactate stays highAdrenaline or salbutamol (beta-2), liver failure, metformin, thiamine deficiency, seizures, malignancy, linezolid, propofol infusion syndrome, mesenteric ischaemia.
- 5
Use more than one target
IntegrateMAP, CRT, mental state, urine output, ScvO2 > 70%, venous-arterial CO2 gap < 6 mmHg, and lactate trend.
Causes of raised lactate
| Type | Examples |
|---|---|
| Type A (hypoperfusion/hypoxia) | Shock of any type, severe hypoxaemia, severe anaemia, CO poisoning, regional ischaemia (mesenteric, limb) |
| Type B1 (disease) | Liver failure, malignancy, sepsis-related aerobic glycolysis, DKA, seizures, thiamine deficiency |
| Type B2 (drugs/toxins) | Adrenaline, salbutamol, metformin, propofol, linezolid, NRTIs, cyanide, methanol, ethylene glycol |
| D-lactate | Short bowel, jejuno-ileal bypass (not measured by usual analysers) |
References
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Persistently raised lactate
Step 1 of ~5
Decision: Signs of hypoperfusion (CRT > 3 s, mottling, oliguria)?
Based on Hernández G, Ospina-Tascón GA, Damiani LP, et al; Prescott HC, Antonelli M, Alhazzani W, et al. Educational use; follow local protocol.
Evidence
- SSC 2026: suggests serial lactate to guide resuscitation in sepsis with raised lactate or septic shock (conditional), individualising fluid after the first bolus rather than giving fluid until lactate normalises; suggests capillary refill time as an adjunct (conditional).
- ANDROMEDA-SHOCK (2019): CRT-targeted resuscitation vs lactate-targeted had a non-significant 28-day mortality difference (34.9% vs 43.4%), less organ dysfunction at 72 h, and less fluid.
Controversies
- Lactate clearance thresholds (10% vs 20%) are arbitrary.
🇮🇳 India notes
- Point-of-care lactate is widely available on blood gas analysers in Indian ICUs; capillary refill needs only a stopwatch, ideal for wards and transfers.
- Thiamine deficiency (beriberi, alcohol use, malnutrition) is an important reversible cause of lactic acidosis in India: give thiamine 200-500 mg IV.
References
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Educational reference for trained clinicians. Check doses against your hospital protocol and the patient in front of you.