Question

A 48-year-old patient known case of chronic kidney disease on hemodialysis, is posted for percutaneous nephrolithotomy (PCNL). Discuss the anaesthetic concerns and technique for conduct of anaesthesia for this patient, with rationale.

Hint:

Coordinate with the nephrology team to ensure proper dialysis timing and avoid intraoperative fluid overload in hemodialysis patients.

Answer 1

Step 1: Anaesthetic Concerns.
In a patient with chronic kidney disease (CKD) undergoing PCNL, the following concerns should be addressed:
- Fluid and Electrolyte Imbalance: Hemodialysis patients often have altered fluid and electrolyte status. Preoperative assessment should include checking serum electrolytes, particularly potassium, as hyperkalemia is a life-threatening risk. Fluid resuscitation should be performed carefully, and intraoperative fluid management should be monitored closely to avoid overload.
- Renal Function: Anesthesia drugs are metabolized differently in CKD patients, so drugs should be carefully selected, considering their renal clearance. Drugs like propofol, fentanyl, and remifentanil are preferred because they are less reliant on renal excretion.
- Anemia: Chronic kidney disease often leads to anemia due to reduced erythropoietin production. Preoperative hemoglobin levels should be monitored, and blood transfusions may be necessary in cases of significant anemia.
- Bleeding Risk: CKD patients on hemodialysis may have an increased risk of bleeding due to platelet dysfunction. Preoperative evaluation of coagulation status is essential, and adjustments may be needed in anticoagulant management.

Step 2: Anaesthesia Technique.
The anaesthesia technique should be tailored to the patient's condition. The following steps outline an appropriate approach:

- Preoperative Preparation:
- Dialysis Timing: If possible, dialysis should be performed the day before surgery to correct fluid and electrolyte imbalances and remove excess uremic toxins.
- Premedication: Premedication with benzodiazepines (e.g., midazolam) may help reduce anxiety and ease induction.

- Induction of Anaesthesia:
- Inhalation Agents: Sevoflurane or isoflurane are typically used for induction and maintenance, as they are less dependent on renal clearance.
- Intravenous Agents: Propofol or etomidate can be used for induction. However, caution should be taken in patients with severe renal impairment as the metabolism of propofol can be affected in the setting of liver dysfunction, though it has minimal renal clearance.
- Airway Management: General anaesthesia is preferred, and an endotracheal tube should be used to secure the airway.
- Intraoperative Monitoring: Careful monitoring of blood pressure, heart rate, oxygen saturation, and ECG is essential. If there are concerns about fluid status, central venous pressure (CVP) monitoring may be useful.
- Pain Management: Opioids like fentanyl or remifentanil should be used cautiously due to their renal clearance. Regional anaesthesia (e.g., epidural or spinal) may be beneficial for pain control, though the use of local anaesthetics should be adjusted for renal function.
- Postoperative Care: Close monitoring in the recovery room is necessary, especially for respiratory function and fluid balance. If there is significant blood loss or fluid retention, additional dialysis may be needed.

Step 3: Conclusion.
The anaesthetic management of a patient with chronic kidney disease on hemodialysis for PCNL requires careful consideration of fluid and electrolyte balance, renal function, and bleeding risk. Tailoring the anaesthesia technique to the patient's condition, involving the nephrology team for coordination of dialysis timing, and careful intraoperative monitoring will help ensure a successful outcome.