How to manage hypoglycemia (low blood glucose) during hemodialysis?

Managing Hypoglycemia During Hemodialysis

Reduce insulin doses aggressively before dialysis (25-50% reduction in basal insulin on pre-dialysis days), provide carbohydrate-rich snacks during dialysis sessions for at-risk patients, and implement continuous glucose monitoring to detect the frequent asymptomatic hypoglycemia that occurs in 46-52% of diabetic dialysis patients. 1, 2

Immediate Recognition and Treatment

Defining the Problem

• Hypoglycemia during hemodialysis is extremely common, occurring in 46-52% of ambulatory diabetic patients and 6.9% of non-diabetic patients on maintenance hemodialysis 1, 3
• Glucose levels drop progressively during hemodialysis, reaching their lowest point at the end of the dialysis session, often falling well below the dialysate glucose concentration 1, 4
• Most hypoglycemic episodes are asymptomatic, making detection without continuous monitoring nearly impossible 1, 4
• Hypoglycemia is associated with increased mortality risk in both diabetic (HR 1.08) and non-diabetic (HR 1.17) hemodialysis patients 3

Acute Management During Dialysis

• For symptomatic hypoglycemia (glucose <70 mg/dL), administer 15-20g of oral glucose immediately and recheck glucose every 15 minutes until levels return above 70 mg/dL 5
• Provide carbohydrate-rich snacks during dialysis for patients with pre-dialysis glucose ≤100 mg/dL, which reduces hypoglycemia recurrence from 46.5% to 15% in subsequent sessions 6, 2
• Repeat treatment until blood glucose normalizes above 70 mg/dL 5

Preventive Insulin Dose Adjustments

Type 1 Diabetes Patients

• Reduce total daily insulin dose by 35-40% when initiating dialysis 1
• Further reduce basal insulin by 25% on pre-hemodialysis days 7, 1
• Adjust carbohydrate ratio to approximately 1:25-30 (less insulin per carb) to account for changes in insulin sensitivity 1

Type 2 Diabetes Patients

• Reduce total daily insulin dose by approximately 50% when on dialysis 7, 1
• For hospitalized patients already on higher insulin doses (≥0.6 units/kg/day), reduce total daily dose by 20% 1
• Use total daily insulin doses <0.23 units/kg/day to minimize hypoglycemia risk, as nearly 65% of hypoglycemic episodes occur with doses >0.20 units/kg 8
• Be aware that 15-30% of ESKD patients may experience "burn-out diabetes," requiring minimal or no insulin therapy 1

Timing Considerations

• 61% of all hypoglycemic episodes occur in the 24 hours prior to a hemodialysis session 8
• Total daily insulin requirements may decrease by 15% post-dialysis 1
• Monitor for post-dialysis hyperglycemia, which typically peaks 2.5 hours after dialysis ends 1

Glucose Monitoring Strategy

Continuous Glucose Monitoring (Preferred)

• Implement continuous glucose monitoring (CGM) as the preferred monitoring method to detect asymptomatic hypoglycemia during and after dialysis sessions 1, 6
• CGM metrics (mean glucose, GMI, time-in-range) are more reliable than HbA1c in dialysis patients 1
• Traditional point-of-care monitoring misses most hypoglycemic episodes 1

Point-of-Care Monitoring Limitations

• Never use glucose meters based on GDH-PQQ or glucose oxidase (GO) methodology in dialysis patients, as they produce falsely elevated readings with peritoneal dialysis solutions containing icodextrin and other interfering substances 7
• Use glucose meters with HK, GDH-NAD, or GDH-FAD methodology instead 7
• Low hematocrit (<35%) may result in falsely high glucose readings with GO-based meters 7
• High triglycerides, uric acid (>20 mg/dL), or bilirubin may cause pseudohypoglycemia 7

Monitoring Frequency

• Monitor blood glucose more frequently on dialysis days and the day after 1
• Check glucose before dialysis, at 30,60,90, and 240 minutes during sessions 9

Glycemic Targets

Target Ranges

• Target fasting glucose levels of 110-130 mg/dL rather than aggressive targets, as very low HbA1c levels are associated with increased mortality in hemodialysis patients (U-shaped mortality curve) 1, 6
• Aim for HbA1c of 7-8% in dialysis patients with high comorbidity burden or hypoglycemia risk, rather than the standard <7% target 1
• Maintain time-in-range between 70-180 mg/dL 1

HbA1c Limitations

• Never rely solely on HbA1c for glycemic management in dialysis patients, as it underestimates mean glucose levels and correlates poorly with actual glycemic control due to decreased red blood cell lifespan, anemia, and erythropoietin use 7, 1
• HbA1c should not be used for long-term glycemic monitoring in CKD stage 5 patients on dialysis 7

Dialysate Glucose Concentration

Evidence-Based Recommendations

• Use dialysate containing 90-100 mg/dL glucose to prevent hypoglycemia, as dialysate with 55 mg/dL glucose does not prevent hypoglycemic episodes 9
• Dialysate with 90 mg/dL glucose prevents hypoglycemia without inducing higher intradialytic glycemia levels 9
• Despite using dialysate containing 100-150 mg/dL glucose, 21% of patients still experience asymptomatic HD-related hypoglycemia, with sensor glucose falling well below the dialysate glucose concentration 4

Non-Pharmacologic Interventions

Nutritional Support

• Provide carbohydrate-rich snacks during dialysis, particularly for patients with pre-dialysis glucose ≤100 mg/dL 6, 2
• Assess for malnutrition in patients with recurrent hypoglycemia, as it is both a cause and consequence of the condition 6
• Ensure proper timing of meals relative to medication administration 5
• Maintain access to glucose-containing foods or glucose tablets 5

Dialysis Prescription Modifications

• Avoid excessive ultrafiltration, which can exacerbate hypotension and compromise glucose homeostasis 7
• Consider slowing the ultrafiltration rate or performing isolated ultrafiltration 7
• Increase dialysate sodium concentration if needed 7
• Switch from acetate to bicarbonate-buffered dialysate 7
• Reduce dialysate temperature 7

Special Populations and Considerations

Non-Diabetic Dialysis Patients

• Hypoglycemia occurs in 6.9% of non-diabetic hemodialysis patients due to decreased gluconeogenesis, impaired counterregulatory hormone responses, and nutritional deprivation 6, 3
• Provide carbohydrate-rich snacks during dialysis for those with pre-dialysis glucose ≤100 mg/dL 6
• Evaluate for malnutrition and adjust dry weight targets as needed 6

Type 1 Diabetes Patients

• Type 1 diabetes is independently associated with higher hypoglycemia risk during hemodialysis 8
• Exercise special caution with insulin dosing in this population 8

Critical Pitfalls to Avoid

• Never use aggressive glycemic targets that increase hypoglycemia risk without mortality benefit in dialysis patients 1
• Do not rely on HbA1c alone for glycemic management, as it underestimates mean glucose and correlates poorly with actual control 7, 1
• Avoid using GDH-PQQ or GO-based glucose meters in dialysis patients due to interference issues 7
• Do not use total daily insulin doses >0.20 units/kg without careful monitoring, as this significantly increases hypoglycemia risk 8
• Recognize that hypoglycemia-related hospitalizations before dialysis initiation strongly predict higher mortality after starting dialysis 1