01Purpose and principlesWhat the treatment does and how it fits into care.
Choose components by the haemostatic defect rather than using them interchangeably. Platelets supply cellular adhesion and aggregation, plasma supplies a broad mixture of procoagulant and anticoagulant proteins, and cryoprecipitate supplies fibrinogen in a smaller volume. Establish whether bleeding is present, its severity and site, the trend in counts and tests, recent antiplatelet or anticoagulant exposure, liver or renal disease and whether an intervention is planned. Control the bleeding source; no component overcomes an open vessel.
NICE divides platelet use into treatment and prophylaxis. In clinically significant bleeding that is not major, transfuse if the count is below 30 × 10⁹/L. Use higher thresholds, up to 100 × 10⁹/L, for severe bleeding or critical sites. The exact aim reflects location and progression: a stable mucosal ooze differs from expanding intracranial haemorrhage. Platelet dysfunction from antiplatelet drugs, uraemia or cardiopulmonary bypass is not captured by count alone and needs specialist, procedural and sometimes viscoelastic assessment.
In non-bleeding patients, the general prophylactic threshold is below 10 × 10⁹/L, but important exclusions prevent reflex use. Do not routinely provide prophylaxis in chronic bone-marrow failure, immune thrombocytopenia, HIT or TTP, where consumption, thrombosis or limited benefit changes the balance. Platelets may still be necessary for life-threatening bleeding or a compelling intervention after specialist review. Fever, sepsis, rapid count decline and other clinical risks can justify an individual threshold rather than an uncritical daily order.
Procedural targets depend on consequence and technique. NICE recommends raising the count above 50 × 10⁹/L for invasive procedures or surgery, considering 50–75 when bleeding risk is high and above 100 for critical-site surgery. Low-risk central venous cannulation and marrow aspiration or trephine generally do not need prophylactic platelets. Neuraxial, obstetric and interventional decisions require the relevant specialty and local guidance because platelet trend, function, anatomy and rescue options matter as much as a single value.
Fresh frozen plasma is a relatively high-volume source of multiple factors. Outside major haemorrhage, consider it for clinically significant bleeding with PT or APTT ratio above 1.5. Do not use it to expand volume or correct a mildly abnormal test in a non-bleeding patient. Consider prophylactic plasma before an invasive procedure only when coagulation is abnormal and the procedural bleeding risk is clinically significant. Dose should be weight based under local policy, commonly 15–20 mL/kg, followed by reassessment rather than one or two arbitrary units.
Plasma is not an all-purpose antidote. Major bleeding related to warfarin requires rapid four-factor PCC plus intravenous vitamin K under the reversal protocol because PCC corrects vitamin K-dependent factors faster and with less volume. Specific reversal agents or PCC-based pathways apply to direct oral anticoagulants. Plasma exchange for TTP uses plasma as replacement but is a disease-specific therapeutic procedure, not an attempt to correct PT. Single-factor deficiency should receive a specific concentrate when available.
Cryoprecipitate is fibrinogen rich and lower volume than plasma. NICE recommends it in clinically significant bleeding when fibrinogen is below 1.5 g/L, and prophylactically before a procedure with significant bleeding risk when fibrinogen is below 1.0 g/L. Give two pools as an adult initial dose and recheck. Pregnancy starts with a physiologically higher fibrinogen; obstetric haemorrhage can become critical at values that would look less striking elsewhere, so follow the obstetric major-haemorrhage target and treat a falling result promptly.
Every haemostatic component can cause allergy, febrile reaction, haemolysis from incompatible plasma, bacterial infection, TRALI and TACO. Use ABO-compatible plasma and platelets according to laboratory policy, with RhD considerations for platelet products and anti-D prophylaxis where advised. Review the post-dose platelet increment or fibrinogen and whether bleeding improved. Poor platelet increments on repeated occasions can reflect sepsis, DIC, splenomegaly, active bleeding or HLA or HPA alloimmunisation and require transfusion-laboratory investigation.
Key points
- Platelets treat or prevent bleeding caused by inadequate platelet number or function; plasma replaces multiple soluble coagulation factors; cryoprecipitate provides concentrated fibrinogen.
- For clinically significant non-major bleeding, NICE recommends platelet transfusion when the platelet count is below 30 × 10⁹/L.
- For severe bleeding or bleeding in a critical site, use a higher platelet threshold up to 100 × 10⁹/L according to severity and location.
- For prophylaxis in a non-bleeding patient without specified exclusions, NICE recommends platelets below 10 × 10⁹/L.
- Do not routinely give prophylactic platelets for chronic bone-marrow failure, immune thrombocytopenia, heparin-induced thrombocytopenia or thrombotic thrombocytopenic purpura.
- Before invasive procedures or surgery, raise platelets above 50 × 10⁹/L; consider 50–75 for higher bleeding risk and above 100 for surgery at critical sites such as the central nervous system or posterior eye.
- Do not routinely give prophylactic platelets for low-risk central venous cannulation or bone-marrow aspiration and trephine biopsy.
- First-line adult platelet dose is one adult therapeutic dose, followed by clinical and count reassessment before another dose unless bleeding is major.
- Consider fresh frozen plasma for clinically significant bleeding with abnormal coagulation tests, using PT or APTT ratio above 1.5 as the NICE decision point outside major haemorrhage.
- Do not use plasma simply to normalise mildly prolonged coagulation tests in a non-bleeding patient; consider it before a procedure only when bleeding risk is clinically significant.
- Consider cryoprecipitate for clinically significant bleeding when fibrinogen is below 1.5 g/L, or prophylactically before a risky procedure when it is below 1.0 g/L.
- First-line adult cryoprecipitate dose is two pools, followed by repeat fibrinogen and clinical reassessment; major or obstetric bleeding follows the local rapid-replacement protocol.
02Indications, selection and cautionsWho may benefit, who needs urgent treatment and important alternatives.
Petechiae, mucosal bleeding or operative ooze with a low count supports platelet replacement when the severity-specific threshold is crossed.
Intracranial, posterior eye or other anatomically dangerous bleeding supports urgent control and a platelet target up to 100 × 10⁹/L.
Active bleeding with broadly prolonged PT or APTT from liver dysfunction, dilution or consumption suggests a role for plasma after cause assessment.
Diffuse bleeding with fibrinogen below 1.5 g/L supports cryoprecipitate or local fibrinogen replacement, especially in massive or obstetric loss.
Repeated poor count increments suggest ongoing consumption, infection, splenic sequestration or immune HLA or HPA antibodies rather than simple underdosing.
An isolated mild PT or APTT prolongation without bleeding or a risky procedure rarely benefits from plasma and exposes the patient to harm.
03Assessment before treatmentTests and checks that guide safe selection.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
First-line: platelet count and trendFirst stepFirst line - Why
- Quantify thrombocytopenia and establish whether it is stable, recovering or being consumed.
- Interpretation and limitations
- Relate the result to bleeding, site and procedure; exclude EDTA clumping on film or citrate sample when the count is unexpected.
- 02
First-line: PT, APTT and fibrinogenFirst line - Why
- Identify multiple-factor deficiency, consumption and hypofibrinogenaemia.
- Interpretation and limitations
- PT or APTT ratio above 1.5 supports plasma only with appropriate bleeding context; fibrinogen thresholds direct cryoprecipitate.
- 03
Blood film - Why
- Confirm platelet number and identify aetiological clues such as schistocytes, blasts or clumping.
- Interpretation and limitations
- Schistocytes with thrombocytopenia and haemolysis raise TTP or DIC; platelet transfusion strategy then depends on diagnosis and bleeding.
- 04
Post-platelet count - Why
- Assess haemostatic increment and detect refractoriness.
- Interpretation and limitations
- An early poor increment suggests immune or severe consumptive loss; repeated results need timing, dose and body-size context and laboratory advice.
- 05
Repeat fibrinogen after replacement - Why
- Confirm that cryoprecipitate achieved the clinical target.
- Interpretation and limitations
- Persistent low or falling fibrinogen indicates continuing consumption or bleeding and requires renewed source control and replacement.
- 06
Viscoelastic testing where validated - Why
- Provide rapid functional guidance during major bleeding.
- Interpretation and limitations
- Use the local algorithm and quality-controlled thresholds; it complements clinical haemorrhage control and conventional laboratory testing rather than replacing them universally.
04Treatment approachPreparation, options, escalation and aftercare.
01Non-major platelet bleedingTreat by severity and countFirst stepClinically significant bleeding occurs with thrombocytopenia.+
- 1Assess site and severity, send count, coagulation, fibrinogen and film and treat the cause.
- 2If the count is below 30 × 10⁹/L, give one adult therapeutic dose; use a higher threshold up to 100 for severe or critical-site bleeding.
- 3Reassess bleeding and the post-dose count before another dose and investigate a poor increment.
02Non-bleeding thrombocytopeniaUse prophylaxis selectivelyA patient has a low count without clinically significant bleeding.+
- 1Confirm the result, trend and diagnosis and look for fever, sepsis or planned intervention.
- 2Give prophylaxis below 10 × 10⁹/L unless a specified exclusion or individual plan applies.
- 3Avoid routine prophylaxis in chronic marrow failure, ITP, HIT or TTP; obtain specialist advice for bleeding or procedures.
03Planned procedureMatch target to procedural riskThrombocytopenia or coagulopathy is present before an invasive procedure.+
- 1Define the procedure, site, urgency, operator technique, platelet trend and rescue options.
- 2For platelets, aim above 50 × 10⁹/L, consider 50–75 for high risk and above 100 for critical-site surgery; omit routine prophylaxis for specified low-risk procedures.
- 3Consider plasma only for abnormal coagulation with clinically significant procedural bleeding risk, then recheck response.
04Bleeding with prolonged coagulationUse plasma for multi-factor deficiencyClinically significant bleeding coexists with PT or APTT ratio above 1.5.+
- 1Identify liver disease, DIC, dilution, anticoagulant or specific-factor deficiency and control the source.
- 2Give ABO-compatible FFP at a weight-based local dose when multi-factor replacement is appropriate.
- 3Repeat clinical assessment and coagulation tests; use PCC or a specific antidote instead when anticoagulant reversal is the actual indication.
05Low fibrinogenReplace concentrated fibrinogenBleeding occurs below 1.5 g/L or a risky procedure is planned below 1.0 g/L.+
- 1Confirm the result and identify major haemorrhage, obstetric loss, DIC, liver failure or dilution.
- 2Give two pools of cryoprecipitate for an adult as the initial NICE dose, or follow the active major-haemorrhage protocol.
- 3Recheck fibrinogen and bleeding promptly and repeat targeted replacement if consumption continues.
05Complications, monitoring and follow-upAdverse effects, response and longer-term review.
- Observe temperature, pulse, blood pressure, respiratory rate and oxygen saturation before and during every platelet, plasma or cryoprecipitate transfusion.
- Reassess the bleeding site and haemodynamic state rather than relying only on laboratory normalisation.
- Check a post-dose platelet count when response will change care, especially before a procedure or when refractoriness is suspected.
- Repeat PT, APTT and fibrinogen after plasma or cryoprecipitate during active bleeding at intervals set by severity and the local protocol.
- Monitor cumulative volume, urine output and respiratory status because plasma-containing components can precipitate TACO.
- Record component traceability, indication, dose, response and any reaction; report serious events through the transfusion service and haemovigilance pathway.
06Special situationsVariants, exceptions and circumstances that change the usual approach.
Count does not equal function
Uraemia, antiplatelet therapy and bypass can impair haemostasis despite a normal number, while some low counts remain clinically dry.
Plasma needs enough volume
One arbitrary unit may expose without materially raising factors; when indicated, use a weight-based dose and reassess.
Fibrinogen falls early
During major and obstetric haemorrhage, fibrinogen may become critically depleted before other standard tests fully express the deficit.
The procedure changes the target
A compressible bedside procedure and intracranial surgery have different consequences and should not share a single prophylactic threshold.
Poor increments have timing
An early post-dose platelet count helps separate immediate immune destruction from later non-immune consumption, although both can coexist.
ABO still matters
Plasma-rich components contain donor anti-A and anti-B, so compatibility and high-titre policies reduce haemolytic risk.
07Common pitfallsFrequent interpretation and management errors.
- 01
Do not use platelets, plasma and cryoprecipitate as interchangeable parts of a generic bleeding pack outside the relevant protocol.
- 02
Do not give prophylactic platelets automatically for ITP, HIT, TTP or chronic marrow failure.
- 03
Do not require prophylactic platelets for low-risk central venous cannulation or marrow biopsy solely because the count is low.
- 04
Do not use plasma to expand volume or normalise a mildly abnormal test in a non-bleeding patient.
- 05
Do not use FFP as first-line warfarin reversal when PCC and vitamin K are indicated.
- 06
Do not prescribe one or two plasma units without considering patient weight and the factor increment required.
- 07
Do not overlook fibrinogen in major or obstetric haemorrhage.
- 08
Do not repeatedly transfuse platelets without investigating a poor increment.
- 09
Do not delay anatomical haemorrhage control while attempting to correct every laboratory value.