Postoperative bleeding

Postoperative bleeding is bleeding from the operative site or another site after surgery, ranging from minor wound ooze to life threatening haemorrhage.

Clinical relevance. Clinically important bleeding affects 1 to 5% of major operations. It accounts for a large share of early reoperations, and unrecognised internal bleeding leads to shock, organ failure and death. Bleeding into closed spaces (neck, retroperitoneum, thigh, compartments) can threaten the airway or limb with little external sign.

Mechanisms. Surgical bleeding arises from an unligated or slipped ligature, a vessel in spasm that reopens as pressure recovers, or an anastomotic or staple line failure. Coagulopathy arises from anticoagulants, antiplatelet drugs, hypothermia, acidosis, dilution, consumption (disseminated intravascular coagulation), liver disease, uraemia, hyperfibrinolysis, thrombocytopenia and inherited disorders.

Classification by timing.

• Primary: during surgery.
• Reactionary: within 24 hours, as blood pressure rises, vasoconstriction wears off, or a ligature slips.
• Secondary: 7 to 14 days, usually from infection eroding a vessel, a pseudoaneurysm or anastomotic breakdown.

Classification by site. Wound and subcutaneous, intracavity (abdominal, thoracic, pelvic), retroperitoneal, gastrointestinal (anastomotic or ulcer), neck (airway threat), joint or muscle, tonsillar bed, genitourinary, intracranial.

Classification of hypovolaemia. Class I (under 15% loss) causes no change; class II (15 to 30%) causes tachycardia and narrow pulse pressure; class III (30 to 40%) causes hypotension, tachycardia over 120 beats/min and confusion; class IV (over 40%) causes collapse. Shock index (heart rate divided by systolic pressure) over 0.9 to 1.0 is a warning sign.

Key distinctions. Rising drain output, expanding swelling, falling haemoglobin or unexplained tachycardia in the first hours point to surgical bleeding. Generalised oozing from all sites suggests coagulopathy.

History.

• Operation, urgency, duration, blood loss, transfusion, difficulties with haemostasis and intraoperative events (hypothermia, hypotension).
• Anticoagulants, antiplatelets, herbal supplements, nonsteroidal drugs, heparin or low molecular weight heparin timing, and doses given before and after surgery.
• Personal or family bleeding history, liver or kidney disease, previous bleeding after surgery or dental extraction, haematological disease and cancer.
• Symptoms: wound swelling, pain, light headedness, thirst, breathlessness, chest pain, haematemesis, melaena, haematuria, neck swelling or stridor.

Examination.

• Vital signs: heart rate, blood pressure, shock index, respiratory rate, capillary refill, urine output, mental state, temperature.
• Wound: swelling, tension, bruising, ooze, saturated dressings. Drains: volume, colour, rate of change, and check patency.
• Abdomen: distension, tenderness, flank or groin bruising (Grey Turner, Cullen), rectal examination. Chest: reduced air entry, tracheal shift, chest drain output.
• Neck: swelling, voice, stridor, and airway compromise after thyroid, parathyroid or carotid surgery. Limbs: tense swelling, pulses, sensation and function.
• Signs of coagulopathy: petechiae, mucosal bleeding, oozing from cannula sites and wound edges.

Red flags.

• Hypotension, tachycardia over 100 beats/min, shock index over 1.0, cold clammy skin, confusion or oliguria.
• Expanding neck swelling with stridor, voice change or dysphagia (airway emergency).
• Drain output over 200 mL/hour for 2 to 4 hours, or over 1.5 L in a single loss, or sudden cessation of a previously productive drain (blocked drain).
• Abdominal distension, rigidity, or rapidly falling haemoglobin.
• Chest drain output over 1.5 L immediately or over 200 mL/hour for 2 to 4 hours.
• Tense limb with pain on stretch and neurovascular signs (compartment syndrome).
• Active bleeding from several sites (coagulopathy) or with hypothermia, acidosis and calcium depletion (trauma triad).
• Sentinel bleed from a surgical wound at 7 to 14 days (impending major arterial haemorrhage).

Special groups. Patients on anticoagulants or antiplatelets need reversal and early specialist advice. Patients with liver disease have impaired clotting synthesis. Patients with kidney failure have platelet dysfunction. Jehovah's Witnesses and others who decline blood need early planning of blood sparing treatment. Pregnant and postpartum patients with bleeding need obstetric emergency management.

Surgical bleeding. Slipped ligature, unrecognised vessel injury, suture or staple line failure, bleeding raw surface or bed (liver bed, retroperitoneum, pelvis), pseudoaneurysm, vascular graft or anastomotic leak, splenic injury, secondary haemorrhage from infection or erosion.

Coagulopathy.

• Drug related: warfarin, heparin, enoxaparin, direct oral anticoagulants, antiplatelets, thrombolytics, nonsteroidal drugs, selective serotonin reuptake inhibitors, herbal products (ginkgo, garlic, ginseng).
• Acquired: dilutional coagulopathy, hypothermia, acidosis, hypocalcaemia, disseminated intravascular coagulation, hyperfibrinolysis, hypofibrinogenaemia, liver disease, vitamin K deficiency, uraemia, thrombocytopenia (heparin induced, drug related, consumptive), transfusion reaction.
• Inherited: haemophilia A and B, von Willebrand disease, platelet disorders, factor deficiencies.

Haemorrhage sites needing specific action. Neck haematoma, tonsillectomy bleeding, post prostate resection bleeding, intra-abdominal haemorrhage, retroperitoneal haematoma, haemothorax, pericardial tamponade, haemarthrosis, compartment haematoma.

Mimics of postoperative shock. Sepsis, myocardial infarction, pulmonary embolism, tension pneumothorax, cardiac tamponade, anaphylaxis, adrenal insufficiency, drug related hypotension, neuraxial block, hypovolaemia from third spacing, and pseudo bleeding (haemodilution with falling haemoglobin but stable condition).

Step 1. Assess haemodynamics and decide whether the patient is unstable (needs immediate resuscitation and surgery) or stable (allows investigation). Send urgent bloods while resuscitating. Step 2.

First line tests:

• Full blood count (repeat every 30 to 60 minutes in active bleeding, because the first haemoglobin lags).
• Group and crossmatch (at least 4 units).
• Prothrombin time, activated partial thromboplastin time, fibrinogen (Clauss) and platelet count.
• Urea, creatinine, electrolytes and ionised calcium.
• Lactate and blood gas (base deficit), and temperature.

Viscoelastic testing (thromboelastography or rotational thromboelastometry) where available directs products and detects hyperfibrinolysis. Anti-Xa level for low molecular weight heparin and some DOACs, and drug level assays for DOACs.

Step 3. Imaging for stable patients, or when the site is uncertain.

• Focused ultrasound for free fluid (abdomen and pelvis), pericardial effusion and haemothorax.
• CT angiography for ongoing bleeding in stable patients to find the source, and to direct embolisation or surgery.
• Chest radiograph for haemothorax, and wound ultrasound for haematoma.
• Endoscopy (upper or lower) for gastrointestinal bleeding, and cystoscopy or imaging for urinary bleeding.

Step 4. Distinguish coagulopathy from surgical bleeding: normal coagulation tests with ongoing bleeding supports a surgical source, whereas abnormal tests and oozing from all sites suggests coagulopathy. Correct coagulopathy but do not delay surgery in a bleeding unstable patient.

Interpretation.

• Fibrinogen under 1.5 g/L, platelets under 50 x 10^9/L, INR over 1.5, prolonged activated partial thromboplastin time, or ionised calcium under 1.1 mmol/L require correction in active bleeding.
• Lactate over 2 mmol/L and base deficit over 4 mmol/L indicate hypoperfusion.

Limitations. Haemoglobin falls late. Conventional tests take 30 to 60 minutes and may not reflect current clot function. Anti-Xa assays are not available everywhere. CT delays surgery in unstable patients.

Immediate priorities.

• Call for senior surgical and anaesthetic help early. Airway first: for neck haematoma with airway threat, open the wound at the bedside (remove sutures or clips, evacuate the clot) before intubation, and prepare for difficult airway and surgical airway.
• Two large bore IV cannulas (or intraosseous access), oxygen, monitoring, urinary catheter, warming (target over 36 degrees Celsius), and tilt or lie flat.
• Send blood tests and group and crossmatch, and activate the massive transfusion process when major bleeding is likely.
• Apply direct pressure to external bleeding. Pack wounds. Keep the patient nil by mouth.

Fluids and blood products.

• Limit crystalloid (no more than 1 L in total in major bleeding) and use blood products early. Permissive hypotension (systolic pressure 80 to 100 mmHg) is appropriate for uncontrolled bleeding until surgical control, except in head or spinal cord injury.
• Massive transfusion: first pack 4 units of red cells, 4 units of plasma (about 15 mL/kg) and 1 adult dose of platelets. Continue red cells, plasma and platelets in about equal proportions with a warmer.
• Add fibrinogen replacement for fibrinogen under 1.5 g/L: cryoprecipitate 2 pools (about 10 units) or fibrinogen concentrate 2 to 4 g IV.
• Give platelets for count under 50 x 10^9/L with active bleeding (under 100 x 10^9/L in neurosurgery and eye surgery).
• Red cells for haemoglobin under 70 g/L in stable patients (under 80 g/L in cardiac disease), and without waiting for the result in unstable patients.
• Calcium chloride 10% 10 mL (1 g) IV over 5 to 10 minutes (via a central or large vein) to keep ionised calcium over 1.1 mmol/L, repeated by level; monitor ECG and avoid infusing through the line used for blood.

Antifibrinolytic.

• Tranexamic acid 1 g IV over 10 minutes, followed by 1 g over 8 hours when bleeding continues (best within 3 hours of onset).
• Maximum 2 g in the first 8 hours for this use.
• Reduce the dose when creatinine is over 120 micromol/L (seek specialist advice, as dosing depends on the creatinine).
• Monitor for seizures with high doses and thrombosis. Avoid in active thromboembolic disease and haematuria from the upper tract.

Reversal of anticoagulants and drugs.

• Warfarin or INR over 1.5 with major bleeding: 4 factor prothrombin complex concentrate 25 to 50 units/kg IV (dose directed by INR and the product label) plus vitamin K 5 to 10 mg IV over 10 minutes; monitor INR at 30 minutes and thrombosis.
• Unfractionated heparin: protamine 1 mg for each 100 units given in the previous 2 to 3 hours, by slow IV injection over 10 minutes (maximum 50 mg in one dose); monitor for hypotension, bradycardia and anaphylaxis.
• Enoxaparin: protamine 1 mg for each 1 mg of enoxaparin given in the last 8 hours (0.5 mg for each 1 mg if 8 to 12 hours, with a maximum of 50 mg); partial reversal only.
• Dabigatran: idarucizumab 5 g IV (2 doses of 2.5 g within 15 minutes).
• Apixaban or rivaroxaban: andexanet alfa. Low dose is 400 mg IV bolus then 4 mg/minute for up to 120 minutes for most patients; the high dose schedule depends on the drug, dose and time of the last anticoagulant dose.
• When andexanet is not available, use 4 factor prothrombin complex concentrate 50 units/kg (maximum 5000 units); monitor for thrombosis.
• Antiplatelet drugs with life threatening bleeding: platelet transfusion (limited benefit for aspirin and clopidogrel in some bleeding) and desmopressin 0.3 micrograms/kg IV over 20 to 30 minutes (maximum 24 micrograms; monitor sodium for hyponatraemia and avoid in coronary disease, and use caution in older adults).
• Desmopressin is also used in uraemic bleeding and mild haemophilia A and von Willebrand disease under haematology advice.
• Thrombolytics: stop infusion, give tranexamic acid, cryoprecipitate and plasma.
• Hypothermia, acidosis and calcium: correct actively.

Surgical and radiological control.

• Return to theatre for haemodynamic instability, expanding haematoma, continuing losses over 200 mL/hour for 2 to 4 hours or over 1.5 L at once, tamponade, airway threat, compartment syndrome, and failure to respond to resuscitation. Do not delay for coagulation correction in a bleeding unstable patient.
• Interventional radiology (angiography with embolisation) for stable patients with arterial bleeding, pseudoaneurysm, and pelvic, splenic or hepatic sources.
• Endoscopic haemostasis for gastrointestinal bleeding.
• Neck haematoma: bedside evacuation then theatre.
• Tonsillar bleeding, post prostate bleeding (irrigation, traction), and wound ooze: local pressure, topical agents, and return to theatre when persistent.

Minor wound bleeding. Pressure, elevation, topical haemostatic dressings, and review of anticoagulants. Resume anticoagulants only after review of bleeding risk and surgical advice (usually 24 to 72 hours after major surgery).

Venous thromboembolism prophylaxis after bleeding.

• Mechanical prophylaxis (intermittent pneumatic compression) while bleeding risk is high.
• Enoxaparin 40 mg subcutaneously once daily once bleeding is controlled, usually 24 to 72 hours later.
• Use 20 mg daily if CrCl 15 to 30 mL/min, and unfractionated heparin 5000 units subcutaneously every 8 to 12 hours if CrCl under 15 mL/min.
• Monitor platelets from day 4 and creatinine.

Monitoring. Continuous ECG and saturation, arterial pressure in unstable patients, hourly urine output, vital signs every 15 minutes until stable then hourly, repeat full blood count, coagulation and fibrinogen every 30 to 60 minutes during active bleeding, lactate, ionised calcium, potassium (red cell transfusion) and temperature. Monitor drains hourly. Review for transfusion complications (transfusion related acute lung injury, circulatory overload, hyperkalaemia, citrate toxicity).

Referral and escalation. Senior surgeon and anaesthetist immediately. Critical care for shock or massive transfusion. Haematology for coagulopathy and reversal. Interventional radiology for embolisation. Transfusion service early. Vascular surgery for graft or arterial bleeding.

Admission criteria. All patients with significant postoperative bleeding stay under monitoring in a high dependency or critical care unit (or return to one) until stable. Minor wound bleeding after discharge needs review if the dressing is saturated or the patient is anticoagulated.

Discharge and safety netting. Discharge when haemoglobin is stable for 24 hours, there is no active bleeding, anticoagulant plans are documented, and follow up is arranged. Patients return for wound swelling, bleeding that soaks the dressing, black or bloody stools, vomiting blood, light headedness, chest pain, breathlessness or limb swelling.