Orthopaedic surgery: tourniquets, cement and blood loss

What it is

Orthopaedic surgery ranges from a hand operation in a healthy young adult to a hip fracture in a frail older person, and it brings a few dangers of its own. Limb tourniquets give a bloodless field but cause pain and hypertension after a while, even under a good block, and on release they send acid, potassium, carbon dioxide and small emboli back into the circulation, with a fall in blood pressure; long inflation injures nerves and muscle. Bone cement and the insertion of a prosthesis into the femoral canal can cause bone cement implantation syndrome: hypoxaemia, hypotension, arrhythmias and sometimes cardiac arrest, mainly in older patients with a hip fracture. Long bone and pelvic fractures release marrow fat into the veins; one to three days later fat embolism syndrome can appear, with breathing difficulty, confusion and a petechial rash. Joint replacement, spine and pelvic surgery can bleed heavily, and tranexamic acid, cell salvage and a restrictive transfusion policy reduce the need for blood. Venous thromboembolism is a major risk, so prophylaxis is planned together with the timing of any neuraxial block. Regional anaesthesia is central: spinal anaesthesia and peripheral nerve blocks give excellent analgesia, and multimodal analgesia allows early mobilisation with fewer opioids.

What changes in this patient

• Tourniquet: inflation raises central volume; after a while causes ischaemic pain and hypertension; deflation brings hypotension and metabolic washout.
• Cement: at cementing and prosthesis insertion, marrow and cement debris embolise to the lungs and raise pulmonary vascular resistance.
• Fat embolism: fat globules from fractured marrow lodge in lung, brain and skin capillaries and trigger inflammation.
• Blood loss: arthroplasty, spinal, pelvic and revision surgery can bleed heavily and hide blood in drapes and drains.
• Thrombosis: hip and knee surgery and lower limb fractures carry a high risk of deep vein thrombosis and pulmonary embolism.
• Position and patients: prone and beach-chair positions, frail patients with hip fracture, and difficult airways in rheumatoid arthritis and ankylosing spondylitis.

Anaesthetic plan (and why)

1. Assess frailty, cognition, heart disease and anticoagulants in hip fracture patients, and aim for surgery without delay — delay worsens outcome.
2. Check the cervical spine in rheumatoid arthritis and the airway and spine in ankylosing spondylitis — instability and rigidity change airway and block plans.
3. Offer spinal anaesthesia or general anaesthesia with a peripheral nerve block, such as a fascia iliaca block for hip fracture — good analgesia, fewer opioids.
4. Record tourniquet inflation time, tell the surgeon as the safe limit approaches, and warn the team before release — limits injury and prepares for hypotension.
5. Before cementing, tell the team, raise inspired oxygen, keep volume full and watch pressure closely — helps the heart withstand the embolic load.
6. Treat cement reactions with oxygen, fluids and vasopressors or inotropes for the right heart — the main problem is acute pulmonary hypertension.
7. Give tranexamic acid when not contraindicated, use cell salvage when blood loss is expected, and transfuse to a restrictive target — reduces blood use.
8. Plan thromboprophylaxis with the surgeon and time it around neuraxial blocks and catheter removal — prevents both clots and spinal haematoma.
9. Pad pressure points and keep the head neutral; in beach-chair position correct blood pressure to brain level — prevents nerve, eye and brain injury.

Three orthopaedic emergencies compared

Risks and complications

• Hypotension and metabolic washout at tourniquet release; nerve injury or muscle damage after prolonged inflation.
• Bone cement implantation syndrome with hypoxaemia, hypotension, right heart failure or cardiac arrest.
• Fat embolism syndrome: hypoxaemia, confusion, petechiae in the armpits, conjunctiva and mouth, sometimes acute respiratory distress syndrome.
• Major bleeding and transfusion; deep vein thrombosis and pulmonary embolism.
• Compartment syndrome, where pain out of proportion is the warning sign; dense blocks require close limb checks.
• Phrenic nerve palsy after an interscalene block; postoperative delirium in older patients; positioning injuries in prone and beach-chair cases.

Next step

• In recovery, check limb perfusion and sensation, blood loss in drains, haemoglobin after major surgery, and pain control before the block wears off.
• Call a senior for new hypoxaemia, confusion or a petechial rash after a long bone fracture, or for pain out of proportion that suggests compartment syndrome.
• Start thromboprophylaxis at the agreed time after surgery and after any neuraxial catheter is removed.
• Continue multimodal analgesia on the ward with regular paracetamol, rescue opioids and a plan for when the block ends, so early mobilisation can start.
• Screen older patients for delirium daily and involve the orthogeriatric team for hip fractures.

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Elsewhere in DurgiPedia

• Mechanical prevention of venous thromboembolism: stockings and intermittent compression
• Fat, air and amniotic fluid embolism
• Pain and temperature: pathways and modulation
• Fractures and fracture healing

Connections

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Educational content; it does not replace supervised training, your institution's protocols or the anaesthetist's or intensivist's decision. It contains no doses and no ventilator or infusion settings.

Sources: Fat Embolism and Fat Embolism Syndrome (StatPearls (NCBI Bookshelf), 2026); Multimodal Postoperative Pain Control After Orthopaedic Surgery (StatPearls (NCBI Bookshelf), 2026).

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