From the Guidelines
Preoperative dialysis is generally recommended for patients with a glomerular filtration rate (GFR) below 5-10 mL/min/1.73m², as this range often correlates with symptoms or signs attributable to kidney failure, inability to control volume status or blood pressure, progressive deterioration in nutritional status, or cognitive impairment, as suggested by 1 and 1. When considering preoperative dialysis, it's crucial to assess the patient's overall clinical condition, including the presence of symptoms such as serositis, acid-base or electrolyte abnormalities, pruritus, and the inability to control volume status or blood pressure, as outlined in 1 and 1.
- The decision to initiate preoperative dialysis should not be based solely on GFR values but should also consider the type of surgery, anticipated fluid shifts, potential for nephrotoxic exposures, and the patient's overall clinical condition.
- For patients with GFR between 15-30 mL/min/1.73m², preoperative dialysis may be considered on a case-by-case basis, particularly for major surgeries with significant fluid shifts or when using contrast agents, as the risk of complications during surgery increases with decreasing kidney function.
- The timing of dialysis is also important, ideally performed 12-24 hours before surgery to optimize fluid status and electrolyte balance while avoiding the anticoagulation effects of dialysis, which can compromise surgical outcomes and recovery, as implied by the need to manage volume status and electrolyte abnormalities in patients with severely reduced kidney function 1.
From the Research
Pre-operative Dialysis Requirements
The requirement for pre-operative dialysis prior to surgery is not explicitly stated in the provided studies. However, the studies provide information on the classification of chronic renal insufficiency and the timing of dialysis initiation.
- The study 2 proposes classifying patients with GFR of 60 to 41 mL/min, 40 to 21 mL/min, and 20 mL/min or below as having mild, moderate, and advanced degrees of chronic renal insufficiency, respectively.
- The study 3 states that there is no recommended estimated glomerular filtration rate (eGFR) threshold for initiating dialysis, and patient-clinician shared decision-making should help determine when to initiate dialysis.
- The study 4 defines chronic kidney disease (CKD) as a GFR less than 60 mL/min/1.73 m2 or persistent evidence of kidney damage on imaging, biopsy, or urinalysis that persists for longer than 3 months.
GFR Levels and Dialysis
The studies do not provide a specific GFR level at which pre-operative dialysis is required prior to surgery. However, they suggest that patients with advanced degrees of chronic renal insufficiency (GFR < 20 mL/min) may require dialysis.
- The study 5 reports on the use of capecitabine in patients with severe renal impairment (GFR < 30 mL/min) and end-stage renal disease on hemodialysis, but does not provide information on pre-operative dialysis requirements.
- The study 6 investigates the impact of fluid overload and variation on residual renal function in peritoneal dialysis patients, but does not address pre-operative dialysis requirements.
Key Findings
The key findings from the studies are:
- Chronic renal insufficiency can be classified based on GFR levels 2.
- There is no recommended eGFR threshold for initiating dialysis 3.
- CKD is defined as a GFR less than 60 mL/min/1.73 m2 or persistent evidence of kidney damage 4.
- Patients with severe renal impairment (GFR < 30 mL/min) can be treated with capecitabine with close monitoring and dose modification 5.
- Fluid overload is associated with a decline in residual renal function in peritoneal dialysis patients 6.