By the end of this note you will be able to recognise, investigate and outline the immediate and definitive management of common coagulation disorders seen in Kenyan clinical rotations, while remembering to verify drug choices and doses against the Kenya MoH guideline and your hospital formulary.
Definition
A coagulation disorder is any abnormality of the haemostatic system that results in either excessive bleeding (hypocoagulability) or pathological clot formation (hypercoagulability). In practice the term is most often applied to acquired or inherited defects that present with abnormal bleeding times, bruising, mucosal haemorrhage, or thrombotic events.
Anatomy and physiology you need
| Component | Role in haemostasis | Key test |
|---|---|---|
| Vascular endothelium | Provides surface, releases von Willebrand factor (vWF) & prostacyclin | Clinical exam (pulses, cap refill) |
| Platelets | Primary plug formation, release granules, provide phospholipid surface | Platelet count, platelet function assay |
| Coagulation cascade (intrinsic & extrinsic) | Generates thrombin → fibrin clot | PT, aPTT, INR, fibrinogen |
| Fibrinolytic system | Dissolves clot via plasmin | D‑dimer, fibrin degradation products |
| Natural anticoagulants (protein C, protein S, antithrombin) | Limit clot propagation | Specific factor assays |
Causes and risk factors
| Category | Common aetiologies in Kenya | Why they matter |
|---|---|---|
| Infectious | HIV (immune dysregulation, ART), TB (disseminated intravascular coagulation), malaria (platelet sequestration, DIC), hepatitis B/C (liver synthetic failure) | High prevalence; often present with mixed bleeding & clotting |
| Hemoglobinopathies | Sickle cell disease (functional asplenia, vaso‑occlusion, chronic hemolysis) | Leads to both thrombosis and bleeding from splenic sequestration |
| Autoimmune / Rheumatic | Systemic lupus erythematosus (antiphospholipid antibodies), rheumatic fever (immune complex vasculitis) | Antiphospholipid syndrome causes hypercoagulability; vasculitis can cause bleeding |
| Liver disease | Chronic hepatitis, alcoholic liver disease, aflatoxin exposure | Liver makes most clotting factors and anticoagulants |
| Nutritional | Vitamin K deficiency (poor diet, broad‑spectrum antibiotics) | Reduces synthesis of factors II, VII, IX, X |
| Medications | Antibiotics (alter gut flora → vit K), antiretrovirals (protease inhibitors), traditional herbal remedies (unknown anticoagulant compounds) | Frequently used; may precipitate bleeding |
| Pregnancy & puerperium | Increased clotting factor levels, reduced protein S | High risk of venous thromboembolism |
| Malignancy | Kaposi sarcoma, lymphomas, solid tumours | Tumour‑derived pro‑coagulants, DIC |
Pathophysiology
Infection or inflammation → cytokine surge → endothelial activation → tissue factor exposure → extrinsic pathway activation → thrombin burst → fibrin formation → consumption of clotting factors → DIC → simultaneous bleeding (factor depletion) and micro‑thrombosis.
HIV → CD4 loss + ART hepatotoxicity → reduced synthesis of factors & natural anticoagulants → prolonged PT/aPTT → bleeding tendency.
Malaria → sequestration of infected RBCs & platelets → platelet count fall + endothelial damage → impaired primary haemostasis → mucosal bleeding.
Sickle cell → chronic hemolysis → nitric oxide scavenging → endothelial dysfunction → pro‑thrombotic state → vaso‑occlusive crises; splenic infarction → thrombocytopenia → bleeding.
Vitamin K deficiency → impaired γ‑carboxylation of factors II, VII, IX, X → prolonged PT > aPTT → bleeding.
Pregnancy → ↑ estrogen → ↑ clotting factor production + ↓ protein S → hypercoagulable state → risk of DVT/PE.
These steps illustrate how a single trigger can shift the balance toward either end of the haemostatic spectrum, depending on the dominant pathway affected.
Clinical features
| Aspect | Key questions / findings | Why it occurs |
|---|---|---|
| Bleeding pattern | • Onset – sudden vs gradual <br>• Site – mucosal (epistaxis, gum, menorrhagia), skin (petechiae, purpura), gastrointestinal, genitourinary, intracranial <br>• Trauma‑related vs spontaneous <br>• Relation to surgery or dental work | The vascular bed and coagulation cascade determine where a defect becomes evident. Platelet disorders give mucocutaneous bleeding; factor deficiencies or liver disease produce deep tissue/hemorrhagic bleeding. |
| Family history | • Consanguinity, known inherited bleeding disorder, early‑onset bleeding in relatives | Inherited deficiencies (e.g., hemophilia A/B, von Willebrand disease) follow autosomal or X‑linked patterns. |
| Medication / substance use | • NSAIDs, aspirin, antiplatelet agents, warfarin, DOACs, traditional herbal remedies, alcohol excess | Drugs can impair platelet function or the coagulation cascade, precipitating bleeding. |
| Infectious / systemic illnesses | • HIV status, TB treatment, recent malaria, sickle‑cell crises, rheumatic fever, liver disease, renal disease | HIV can cause thrombocytopenia; TB and malaria may trigger DIC; sickle cell and rheumatic disease can cause splenic sequestration or immune‑mediated platelet destruction. |
| Pregnancy / obstetric history | • Prior postpartum hemorrhage, placental abnormalities, pre‑eclampsia | Pregnancy stresses the hemostatic system; underlying disorders become apparent during delivery. |
| Surgical / invasive procedures | • Recent or planned surgery, catheterisation, biopsies | Provides a stress test for hemostasis; excessive bleeding points to a disorder. |
| Constitutional symptoms | • Fever, weight loss, night sweats, fatigue | May indicate underlying infection, malignancy or systemic inflammation that can trigger consumptive coagulopathy. |
| Physical examination | • Skin – petechiae, purpura, ecchymoses, bruises, hematomas (platelet or vascular fragility) <br>• Mucosa – bleeding gums, epistaxis, menorrhagia (platelet or von Willebrand) <br>• Jaundice – suggests liver disease affecting clotting factor synthesis <br>• Hepatosplenomegaly – portal hypertension, sequestration of platelets <br>• Lymphadenopathy / organomegaly – possible hematologic malignancy <br>• Signs of DIC – diffuse oozing from venipuncture sites, shock, organ dysfunction | Each sign reflects a specific component of hemostasis: platelet number/function, coagulation factor levels, vascular integrity, or consumptive processes. Recognising the pattern directs further testing. |
Differential diagnosis
| Condition | Points toward it | Distinguishing feature |
|---|---|---|
| Platelet quantitative defect (thrombocytopenia) | Low platelet count, mucocutaneous bleeding, recent infection or drug exposure | Normal PT/aPTT, isolated low platelet count |
| Platelet qualitative defect (e.g., aspirin, uremia) | Bleeding despite normal count, drug history, renal failure | Prolonged bleeding time, normal PT/aPTT |
| von Willebrand disease | Mucosal bleeding, family history, menorrhagia, normal platelet count | Prolonged aPTT, low VWF antigen/activity, abnormal ristocetin aggregation |
| Hemophilia A / B | Deep tissue bleeding, hemarthroses, male sex, family history | Isolated prolonged aPTT, normal PT, low factor VIII or IX |
| Liver disease‑related coagulopathy | Jaundice, hepatomegaly, alcohol use, hepatitis, HIV | Prolonged PT/INR, low factor levels, normal platelets early |
| Disseminated intravascular coagulation (DIC) | Sepsis, severe malaria, obstetric complications, shock | Prolonged PT/aPTT, low fibrinogen, high D‑dimer, thrombocytopenia |
| Acquired factor inhibitor | Unexpected bleeding on anticoagulant therapy, lupus anticoagulant, postpartum | Mixing study fails to correct PT/aPTT, presence of inhibitor titers |
Investigations
| Test | What it answers | Interpretation |
|---|---|---|
| Complete blood count (CBC) with smear | Platelet number, anemia, leukocytosis | Thrombocytopenia → platelet problem; schistocytes → microangiopathic hemolysis/DIC |
| Prothrombin time (PT) / INR | Extrinsic pathway integrity, factor VII & common pathway | Prolonged → liver disease, vitamin K deficiency, warfarin effect |
| Activated partial thromboplastin time (aPTT) | Intrinsic pathway (VIII, IX, XI, XII) & common pathway | Prolonged → hemophilia, lupus anticoagulant, heparin effect |
| Fibrinogen level | Consumptive coagulopathy vs liver synthesis | Low → DIC or severe liver disease |
| D‑dimer | Fibrin degradation, ongoing clot breakdown | Elevated → DIC, thromboembolism, severe infection |
| Factor assays (VIII, IX, V, VII, X) | Specific factor deficiencies | Low factor VIII → hemophilia A; low factor IX → hemophilia B; multiple low → liver disease |
| von Willebrand factor antigen & activity (ristocetin cofactor) | Presence and function of VWF | Low antigen/activity → VWD; normal → other causes |
| Mixing study (patient plasma + normal plasma) | Presence of inhibitor vs factor deficiency | No correction → inhibitor; correction → deficiency |
| Liver function tests (ALT, AST, bilirubin, albumin) | Synthesis capacity of clotting factors | Abnormal → hepatic contribution |
| Renal function & urinalysis | Uremic platelet dysfunction | Elevated creatinine, proteinuria → consider uremic platelet defect |
| HIV, hepatitis B/C serology | Underlying infectious contributors | Positive → HIV‑associated thrombocytopenia, hepatitis‑related coagulopathy |
| Blood culture / malaria smear | Identify sepsis or malaria as DIC trigger | Positive → treat underlying infection |
Diagnosis and severity
- Establish the primary defect
- Platelet‑related – isolated thrombocytopenia or abnormal bleeding time with normal PT/aPTT.
- Coagulation factor‑related – isolated PT or aPTT prolongation, confirmed by factor assay.
- Combined/consumptive – abnormalities in PT, aPTT, fibrinogen, D‑dimer, and platelets (suggesting DIC).
- Classify severity (clinical rather than numeric)
| Severity | Clinical criteria | Management focus |
|---|---|---|
| Mild | Minor mucosal bleeding, no hemodynamic impact, platelet >50 × 10⁹/L, PT/INR <1.5, aPTT <1.5× control | Observation, treat reversible causes, prophylactic measures |
| Moderate | Frequent mucocutaneous bleeding, menorrhagia, epistaxis requiring medical attention, platelet 30‑50 × 10⁹/L, PT/INR 1.5‑2.5, aPTT 1.5‑2.5× control | Targeted replacement (platelets, VWF concentrate, factor concentrates), address underlying disease |
| Severe / life‑threatening | Intracranial, gastrointestinal, or surgical bleeding; hemodynamic instability; platelet <30 × 10⁹/L, PT/INR >2.5, aPTT >2.5× control, fibrinogen <1 g/L | Urgent hemostatic therapy (massive transfusion protocol, specific factor concentrates, antifibrinolytics), intensive monitoring, treat precipitating cause (e.g., infection, liver failure) |
- Confirmatory diagnosis – combine history, exam, and the pattern of laboratory abnormalities. For inherited disorders, family studies and genetic testing (where available) may be added. For acquired disorders, identify and treat the trigger (e.g., antiretroviral therapy for HIV, antimalarials, anti‑TB drugs, antibiotics for sepsis).
- Document severity in the patient chart, noting the specific laboratory thresholds and clinical manifestations, to guide therapy escalation and to communicate risk to surgical or obstetric teams.
Management
| Phase | Goal | Key actions | Monitoring / safety |
|---|---|---|---|
| Immediate stabilisation | Preserve life, stop active bleeding | • Secure airway, breathing, circulation (IV access, fluids) <br>• Apply pressure dressings or tourniquet for limb bleeds <br>• Transfuse packed red cells if haemodynamic compromise <br>• Give fresh frozen plasma (FFP) or prothrombin complex concentrate (PCC) for severe INR elevation or factor deficiency <br>• Give cryoprecipitate for isolated fibrinogen <br>• Administer tranexamic acid early in trauma‑related bleeding | • Vital signs q15‑30 min until stable <br>• Repeat PT/INR, aPTT, fibrinogen after each product <br>• Watch for transfusion reactions, volume overload |
| Definitive treatment | Correct underlying cause, restore haemostasis | • Vitamin K for warfarin‑related coagulopathy or malnutrition <br>• Antifibrinolytics (tranexamic acid, epsilon‑aminocaproic acid) for hyperfibrinolysis <br>• Specific factor concentrates (e.g., recombinant factor VIII for haemophilia A) <br>• Desmopressin (DDAVP) for mild haemophilia A, von Willebrand disease, or uremic platelet dysfunction <br>• Treat infections (TB, malaria, HIV) that precipitate DIC or thrombocytopenia <br>• Manage autoimmune causes with steroids or rituximab <br>• For DIC, replace depleted components (FFP, platelets, cryoprecipitate) and treat trigger | • Daily PT/INR, aPTT, fibrinogen, D‑dimer while on therapy <br>• Platelet count q12‑h if thrombocytopenic <br>• Renal & hepatic function for drug clearance <br>• Watch for thrombotic complications when using PCC or factor concentrates |
| Long‑term follow‑up | Prevent recurrence, monitor for late effects | • Education on medication adherence (e.g., warfarin monitoring) <br>• Periodic screening for inhibitor development in haemophilia <br>• Vaccination and prophylaxis for HIV/TB patients on long‑term anticoagulation <br>• Assess for chronic organ damage (renal, hepatic) | • Outpatient coagulation profile every 3‑6 months (or sooner if unstable) <br>• Review of bleeding diary, quality‑of‑life scores |
Contra‑indications / safety notes
- Avoid tranexamic acid in patients with active intravascular clotting (e.g., recent myocardial infarction, stroke).
- PCC should not be given without confirming INR > 2 or active bleeding, due to thrombotic risk.
- Desmopressin is contraindicated in severe coronary artery disease or uncontrolled hypertension.
- Fresh frozen plasma is contraindicated in patients with severe fluid overload unless absolutely necessary.
Complications and prognosis
- Acute complications: hypovolemic shock, organ hypoperfusion, intracranial haemorrhage, massive transfusion‑related coagulopathy, transfusion reactions, thromboembolism from over‑correction.
- Chronic sequelae: iron‑deficiency anaemia, joint disease in haemophilia, renal impairment from repeated micro‑thrombi in DIC, psychosocial impact of recurrent bleeds.
- Prognosis depends on:
- Speed of recognition and correction of the coagulopathy.
- Underlying aetiology (infectious triggers like malaria have good prognosis once cleared; severe inherited factor deficiencies carry lifelong risk).
- Presence of comorbidities (advanced HIV, liver cirrhosis worsen outcomes).
High‑yield exam points
- Look‑alike conditions: DIC vs. severe liver disease vs. massive transfusion syndrome – all give prolonged PT/aPTT but fibrinogen falls only in DIC.
- Commonest wrong first step: Giving vitamin K alone in warfarin‑related bleeding without FFP/PCC when INR > 4.
- Bedside examiner questions:
- “Explain why a patient with isolated prolonged aPTT and normal PT is likely to have a factor VIII or IX deficiency.”
- “What is the rationale for using tranexamic acid within 3 h of trauma?”
- “How would you differentiate thrombocytopenia from platelet dysfunction on exam?”
- Key pearls:
- “Bleeding time is rarely used now; platelet function is assessed with PFA‑100 or aggregometry.”
- “In HIV, thrombocytopenia is often immune‑mediated and responds to steroids.”
Clinical case
Case: A 28‑year‑old male with known sickle cell disease presents with sudden left flank pain, bruising over the abdomen, and a drop in haemoglobin from 12 g/dL to 8 g/dL over 6 h. Vital signs: BP 90/60 mmHg, HR 118 bpm. Labs: PT 14 s (normal), aPTT 48 s (prolonged), fibrinogen 1.0 g/L (low), platelets 90 ×10⁹/L, D‑dimer markedly raised.
Questions
- What is the most likely coagulation disorder?
Answer: Acute disseminated intravascular coagulation (DIC) secondary to sickle‑cell vaso‑occlusive crisis with marrow infarction.
- What is the immediate management priority?
Answer: Stabilise haemodynamics with crystalloids and packed red cells, give fresh frozen plasma and cryoprecipitate to replace depleted clotting factors and fibrinogen, and treat the underlying trigger (pain control, hydration, exchange transfusion if indicated).
- Which laboratory trend would indicate successful treatment?
Answer: Rising fibrinogen toward normal, decreasing D‑dimer, and normalising aPTT while platelet count stabilises.
Practice questions
Question 1
A 45‑year‑old woman on warfarin for atrial fibrillation presents with a spontaneous intracerebral haemorrhage. Her INR is 5.5. What is the most appropriate next step?
A. Hold warfarin and observe
B. Give vitamin K orally only
C. Administer fresh frozen plasma plus intravenous vitamin K
D. Start low‑molecular‑weight heparin
Answer: C. administer fresh frozen plasma plus intravenous vitamin K
Explanation: Rapid reversal is required; FFP provides clotting factors while IV vitamin K restores synthesis.
Question 2
A 7‑year‑old boy with known haemophilia A (factor VIII deficiency) presents with a knee bleed. Which agent is first‑line for controlling the bleed?
A. Desmopressin
B. Recombinant factor VIII concentrate
C. Fresh frozen plasma
D. Tranexamic acid
Answer: B. recombinant factor VIII concentrate
Explanation: Specific factor replacement directly corrects the deficiency; desmopressin is only useful in mild haemophilia A.
Question 3
A 32‑year‑old man with untreated HIV presents with petechiae, a platelet count of 30 ×10⁹/L, normal PT/aPTT, and a normal fibrinogen. Which finding would most support immune‑mediated thrombocytopenia?
A. Positive direct antiglobulin test
B. Elevated serum ferritin
C. Presence of antiplatelet antibodies
D. Low ADAMTS‑13 activity
Answer: C. presence of antiplatelet antibodies
Explanation: Immune thrombocytopenia is characterised by auto‑antibodies against platelet surface antigens.
Question 4
A patient with severe malaria develops bleeding from mucosal sites, PT 18 s, aPTT 55 s, fibrinogen 0.8 g/L, and D‑dimer markedly raised. Which statement best describes the pathophysiology?
A. Primary platelet production defect
B. Consumption coagulopathy due to widespread activation of coagulation
C. Isolated vitamin K deficiency from malabsorption
D. Liver failure causing reduced synthesis
Answer: B. consumption coagulopathy due to widespread activation of coagulation
Explanation: The pattern of prolonged PT/aPTT, low fibrinogen and high D‑dimer is classic for DIC, common in severe malaria.
Question 5
A 60‑year‑old man on long‑term heparin for DVT prophylaxis develops a sudden drop in platelets from 250 ×10⁹/L to 80 ×10⁹/L after 7 days. Which action is recommended?
A. Continue heparin and monitor
B. Switch to low‑molecular‑weight heparin
C. Stop all heparin and start a direct thrombin inhibitor
D. Give platelet transfusion
Answer: C. stop all heparin and start a direct thrombin inhibitor
Explanation: This is typical for heparin‑induced thrombocytopenia; heparin must be stopped and an alternative anticoagulant started.
Drafted with AI assistance from standard references and reviewed for structure. Check details against your lecture notes and the Kenya MoH guideline.