Tourniquet Use During Orthopaedic Surgery

Question 1

A 29-year-old male patient is undergoing urgent orthopaedic surgery to his distal upper limb for tendon damage due to trauma. He has a history of sickle cell disease, but no other medical conditions. The surgeons require the use of a tourniquet.

What are the indications for tourniquet use?

Answer 1

• To provide a bloodless, clear surgical field for distal limb procedures and decrease the risk of perioperative bleeding.
• For intravenous regional anaesthesia (Bier’s block).
• In pre-hospital medicine for patients with a catastrophic major
  haemorrhage.
• Intravenous regional sympathectomy in the management of complex
  regional pain syndromes.
• Isolated limb perfusion in the management of localised malignancy.

Question 2

What are the systemic effects of tourniquet use in limb surgery?

Answer 2

Cardiovascular:
* Overall increase in systemic vascular resistance after tourniquet application.

• Increased effective blood volume in the central circulation with a rise in the central venous and systemic arterial pressures seen as a result.
• An increase in heart rate and blood pressure is seen after 30–60 minutes which persists until deflation of the tourniquet. This phenomenon is referred to as “tourniquet pain”.

Respiratory:
* No effect on tourniquet inflation.

• Tourniquet deflation causes a sudden increase in end tidal carbon dioxide due to the release of end products of metabolism in the blood distal to the tourniquet.

Neurological:
* No systemic effects with inflation, but on deflation the increased PaCO2 leads to an increase in cerebral blood flow through vasodilation.

• A conduction block is seen in both motor and sensory nerves local to the tourniquet, which is reversed on tourniquet deflation.

Question 3

What are the systemic effects of tourniquet use in limb surgery?

Continued…

Answer 3

Haematological:
* Tourniquet inflation leads to a hypercoagulable state secondary to platelet aggregation, although the relationship between coagulation and tourniquet use is complicated and there may be a short period of increased thrombolytic activity on tourniquet deflation.

Other
* An increase in temperature is seen after inflation as heat is conserved in a smaller space, which is reversed on tourniquet deflation due to mixing of blood in the two compartments.

• After 1–2hours of limb ischaemia, there is a modest increase in arterial plasma potassium and lactate concentrations after tourniquet release.
• Local ischaemic changes and anaerobic metabolism in muscular cells also take place following a period of tourniquet inflation.

Question 4

What is post-tourniquet syndrome?

Answer 4

• Post-tourniquet syndrome occurs in patients who have had a prolonged tourniquet time. It is the most common morbidity associated with tourniquet use.
• It is caused by a combined effect of muscle ischaemia, oedema and microvascular congestion.
• Symptoms include limb stiffness, generalised weakness and numbness, which is subjective. Paralysis is not a feature. The limb may be swollen and pale.
• It can last from days to weeks, and is thought to occur due to the effects of localised oedema and ischaemic changes that take place due to prolonged tourniquet inflation.

Question 5

What are the concerns with tourniquet use in this patient? How do you proceed?

Answer 5

• Sickle cell disease is a genetic haemoglobinopathy that causes deformation and sickling of red blood cells under conditions such as hypoxia and stress. This is likely to occur in the residual blood distal to the inflated tourniquet.
• There is no absolute contraindication to the use of tourniquets in patients with sickle cell disease. A senior-led multidisciplinary discussion should be undertaken where the risk of complications relating to tourniquet use should be weighed against the benefits of reduced blood loss and improved operating conditions.

Question 6

The surgeons proceed with surgery using a tourniquet. How can this patient be optimised during the perioperative period?

Preoperative?

Answer 6

Issues: CCF, pHTN, CKD, CVA, Chronic pain, Opioid intolerance, Anaemic

The focus should be on preventing their haemoglobin sickling and causing a vaso-occlusive crisis.

Preoperative:
* Maintain adequate hydration through IV and oral fluids with minimal fasting.

• Preoperative chest physiotherapy and pulmonary function testing may be indicated in patients with associated lung disease.
• Investigations should include haemoglobin and a group and save (with a cross match if severely anaemic).
• Discussions with haematology regarding transfusion may be required as management is complicated. A guiding principle is to reduce the concentration of HbS and achieve adequate haemoglobin for oxygen delivery, while avoiding the sequelae of over-transfusion.

Question 7

The surgeons proceed with surgery using a tourniquet. How can this patient be optimised during the perioperative period?

Intraoperative + Postoperative?

Answer 7

Intraoperative:
* Maintenance of optimal conditions including oxygenation and normocapnia. An arterial line may be necessary.

• Strict temperature monitoring and control.
• Optimisation of analgesia with multimodal techniques.
• Minimise tourniquet time and use the lowest acceptable inflation
  pressure.
• Consider regional anaesthesia. The vasodilation may reduce the risk of a vaso-occlusive crisis postoperatively and also reduce reliance on opioid analgesia in a patient that may be tolerant.

Postoperative:
* Close monitoring on a high dependency unit.
* Continue adequate oxygenation, warming, analgesia and hydration.
* Appropriate venous thromboembolism prophylaxis.