Revision Hip Surgery

Question 1

A 76-year-old gentleman is undergoing revision of a total hip replacement due to loosening of his primary replacement and pain. He has a history of hypertension, for which he takes captopril, mild aortic stenosis, a hiatus hernia and is a smoker.
What are the key concerns in the management of this patient?

Answer 1

Surgical:
* Compared to primary hip surgery, revision surgery increases the risks of the following:
- Intraoperative complication rate, which includes perforation of
the femur and intraoperative fracture.
- Increased operative time, blood loss and surgical complexity.
- Postoperative infection.
- Poor wound healing.
- Venous thromboembolism.

Anaesthetic:
* Prolonged surgical time leads to an increased risk to the patient due to:
- Prolonged mechanical ventilation if a general anaesthetic is used and increased incidence of postoperative pulmonary complications.
- Higher risk for perioperative hypothermia.

Patient:
* Advanced age, smoking status and comorbidities may compound some of the risks mentioned above.

Question 2

What are the risk factors for the development of a postoperative joint infection?

Answer 2

Patient factors:
* Diabetes mellitus.
* High BMI.
* Smoker.
* Malnutrition.
* Immune suppression.
* Pre-existing infection relating to:
- The overlying skin (e.g. cellulitis).
- The joint prosthesis.
- An unrelated cause contributing to a bacteraemia (e.g. UTI/
pneumonia).

Surgical factors:
* Prolonged procedure.
* Lack of laminar flow ventilation.
* Postoperative haemorrhage.
* Catheter insertion.

Question 3

How can this patient be optimised prior to surgery?

Answer 3

This optimisation process should start with a thorough preoperative history, examination and review of recent investigations to explore the relevant comorbidities. This will guide further investigation and identify correctable pathology to treat. The interventions most pertinent to this patient include the following:
* Encourage the patient to stop smoking and engage in local services.

• Refer for lung function tests if the patient is a long-term smoker to
  determine the presence and extent of lung disease.
• Review a 12-lead ECG and recent echocardiogram to determine the
  severity of aortic stenosis and associated cardiac pathology.
• Ensure that the patient’s blood pressure is appropriately treated with
  targets that take into account the aortic valve pressure gradient.
• Investigate and correct common treatable pathology including:
• Anaemia.
• Electrolyte imbalance.
• Blood sugar control in diabetes.
• Coagulopathy.
• Sign-post to weight loss services if applicable to the patient.
• MRSA/MSSA decolonisation.
• Provide preoperative nutritional supplements.
• Educate the patient through local services to encourage adequate
  nutrition, exercise and reduced alcohol intake (prehabilitation).

Question 4

How would you anaesthetise this patient?

No right answer!!

Preoperative?

Answer 4

• Preoperative management should focus on identifying risk factors as identified above.
• The patient should have a valid group and save or have blood cross- matched if the risk of bleeding is sufficiently high. They should be consented for blood transfusion.
• The supervising consultant anaesthetist should be informed of the case due to the potential complications that may arise.
• Premedication, for example, with paracetamol, ranitidine and metoclopramide. The patient’s normal dose of captopril should be omitted for 48 hours.
• Ensure availability of a higher care bed, according to the local protocols.
• Ensure AAGBI monitoring, resus equipment, difficult airway trolley and emergency drugs are readily available.

Question 5

How would you anaesthetise this patient?

Intraoperative and Postoperative?

Answer 5

GA - if likely prolonged/risk of haemorrhage
RA (spinal/CSE) - if likely shorter/lower bleeding risk
Very dependent on local experience/expertise, so communication with surgeon is vital!

Without the benefit of an echocardiogram to quantify the aortic stenosis, and without specific reassurance from the surgical team about the nature of the operation, the most appropriate choice of anaesthetic for this case would be to perform a general anaesthetic. The hiatus hernia demands a rapid sequence induction. As the procedure has the potential to be long, choose maintenance drugs with a quicker offset such as propofol or sevofurane. A particular challenge for this anaesthetic will be to reduce blood loss and maintain stable haemodynamics.

Question 6

How would you anaesthetise this patient?

Intraoperative and Postoperative?

Continued…

Answer 6

• Insert at least one large bore intravenous cannula.
• Site invasive blood pressure monitoring if blood loss is likely to be
  excessive, or if there is evidence of moderate/severe aortic stenosis.
• Proactive management of blood pressure using crystalloid fluids, a
  vasopressor such as metaraminol and targeted blood products.
• Administer tranexamic acid.
• Actively warm the patient.
• Discuss intraoperative cell salvage with the surgical team.
• Discuss the timing of antibiotics with the surgeon as swabs may need
  to be taken to send to microbiology prior to administration.
• Analgesia should be multi-modal. A nerve block, such as a fascia iliaca block, should be considered to help with postoperative pain.

Postoperative:
* Close monitoring on a suitable ward, with a low threshold for critical care admission if there is significant blood loss.

• Continue adequate oxygenation, warming, analgesia and hydration.
• Appropriate venous thromboembolism (mechanical and chemical).

Question 7

What are the options for analgesia in this patient?

Answer 7

• Simple analgesia: paracetamol. NSAIDs are contraindicated in this case due to the patient’s age, hypertension, ACE inhibitor and bleeding risk, which together would increase the risk of an acute kidney injury.
• Opioid-based analgesia: intravenous morphine/fentanyl perioperatively; oxycodone, oramorph and tramadol postoperatively. Patient-controlled analgesia (PCA) may be necessary postoperatively.
• Opioid sparing agents such as ketamine, lidocaine infusion, magnesium and gabapentin.
• Regional anaesthesia: The choice will depend on the surgical approach and anaesthetic expertise. Options include a fascia iliaca block, a pericapsular nerve group (PENG) block, local anaesthetic field block or a wound catheter.
• Neuraxial anaesthesia: single shot spinal (with intrathecal opioids) and lumbar epidural infusion/patient-controlled epidural analgesia.