Hypoglycemic coma in a diabetic patient on peritoneal dialysis due to interference of icodextrin metabolites with capillary blood glucose measurements

Narrative Review of glycaemic management in people with diabetes on peritoneal dialysis

There is an increasing number of people with diabetes on peritoneal dialysis (PD) worldwide. However, there is a lack of guidelines and clinical recommendations for managing glucose control in people with diabetes on PD. The aim of this review is to provide a summary of the relevant literature and highlight key clinical considerations with practical aspects in the management of diabetes in people undergoing PD. A formal systematic review was not conducted because of the lack of sufficient and suitable clinical studies. A literature search was performed using PubMed, MEDLINE, Central, Google Scholar and ClinicalTrials.gov., from 1980 through February 2022. The search was limited to publications in English. This narrative review and related guidance have been developed jointly by diabetologists and nephrologists, who reviewed all available current global evidence regarding the management of diabetes in people on PD.We focus on the importance of individualized care for people with diabetes on PD, the burden of hypoglycemia, glycemic variability in the context of PD and treatment choices for optimizing glucose control. In this review, we have summarized the clinical considerations to guide and inform clinicians providing care for people with diabetes on PD.

Glucose measurement in body fluids: A ready reckoner for clinicians

BACKGROUND AND AIMS

Blood glucose measurement is central to the diagnosis and management of patients with diabetes. Considering that a clinician relies heavily on blood (or rarely other body fluid) glucose values for decision making, an understanding of the basic aspects of glucose measurement in body fluids is necessary.

METHODS

A literature search was conducted in PubMed for articles in English on measurement of glucose in body fluids.

RESULTS

Glucose can be measured in several body fluids, namely blood, interstitial fluid, urine, cerebrospinal fluid, pleural fluid and ascitic fluid in appropriate clinical settings. For blood glucose measurement, the present-day enzymatic methods have replaced the older reducing and condensation methods on account of their better accuracy. It is important to consider preanalytical factors such as sample collection, storage and transport when analyzing a laboratory blood glucose report. The measurement of glucose in interstitial fluid using continuous glucose monitoring system (CGMS) enables better understanding of glucose trends and fluctuations. The CGMS data should be reported using standard metrics which include parameters such as mean 24-h glucose, glycemic variability and time-in, below and above range. The measurement of glucose in urine sample is rarely ever used these days and should be reserved for exceptional circumstances.

CONCLUSION

This review provides a detailed account of various aspects of glucose measurement including their evolution, pitfalls, and their utility in current clinical practice.

Basal-Bolus Insulin Regimen for Hospitalised Patients with COVID-19 and Diabetes Mellitus: A Practical Approach

BACKGROUND AND AIM

The coronavirus disease 2019 (COVID-19) outbreak has rapidly crossed international boundaries and placed increasing demands on healthcare facilities worldwide. Patients with diabetes and uncontrolled blood glucose levels are at increased risk for poor clinical outcomes and in-hospital mortality related to COVID-19. Therefore, achieving good glycaemic control is of paramount importance among hospitalised patients with COVID-19. Basal-bolus insulin therapy is a safe and effective intervention for the management of hyperglycaemia in hospitalised patients. The aim of this article is to provide a practical guidance for the use of the basal-bolus insulin regimen in hospitalised patients with COVID-19 and diabetes mellitus.

METHODS

This guidance document was formulated based on the review of available literature and the combined personal experiences of the authors. We provide a comprehensive review on the use of the basal-bolus insulin regimen, including its principles, rationale, indications, prerequisites, initiation, and dose titration, and also suggest targets for blood glucose control and different levels of capillary blood glucose monitoring. Various case scenarios are used to illustrate how optimal glucose control can be achieved, such as through adjustments in doses of prandial and basal insulin, the use of correctional insulin dosing and changes in the timing and content of major and minor meals.

CONCLUSION

The practical guidance for the use of the basal-bolus insulin regimen in hospitalised patients with COVID-19 and diabetes mellitus presented here can be used for patients admitted to hospital for indications other than COVID-19 and for those in ambulatory care.

Spurious elevation of glucose concentration during administration of high dose of ascorbic acid in a patient with type 2 diabetes on hemodialysis

We describe herein a case of life-threatening hypoglycemia due to spurious elevation of glucose concentration during the administration of ascorbic acid in a type 2 diabetic patient. A 31-year-old female was admitted for proliferative diabetic retinopathy treatment and prescribed high dose ascorbic acid. During hospitalization, she suddenly lost her consciousness and her glucose concentration was 291 mg/dL, measured using self-monitoring blood glucose (SMBG) device, while venous blood glucose concentration was 12 mg/dL. After intravenous injection of 50% glucose solution, the patient became alert. We reasoned that glucose measurement by SMBG device was interfered by ascorbic acid. Physicians should be aware of this interference; high dose ascorbic acid may cause spurious elevation of glucose concentration when measuring with SMBG devices.

Maltose interference-free test strips for blood glucose testing at point-of-care: a laboratory performance evaluation

BACKGROUND

Maltose interference is a concern with blood glucose testing at point-of-care. We evaluated a maltose interference-free test strip (with a modified recombinant glucose dehydrogenase-pyrroloquinoline quinone system) for the Accu-Chek(®) Performa glucose meter (Roche Diagnostics, Mannheim, Germany).

METHODS

Blood specimens (n = 120) sent for clinical laboratory glucose testing were used in assessing performance characteristics, including imprecision, linearity, clinical impact analysis, and method comparison, of the test strips. To evaluate sugar interference, two heparinized blood specimens were spiked with maltose, xylose, and galactose (up to 500 mg/dL) followed by testing with modified Performa, Accutrend(®) (Roche Diagnostics), and Advantage II (Roche Diagnostics) test strips and by the laboratory method.

RESULTS

Test strips demonstrated total laboratory coefficients of variation of <7%; within-run coefficients of variation were 2.7-5.4% for blood glucose at 2.5-19.7 mmol/L. Clarke Error Grid analysis of the 120 results (0.8-27.6 mmol/L) showed all values to be within critical clinical limits. Comparison with laboratory results gave 0.960 correlation (Spearman's r(2)) with a Deming regression y (Performa) = 0.95x (laboratory) - 0.11 mmol/L (SEy|x0.06 mmol/L). A slight negative bias (-0.5 mmol/L) was demonstrated with the Bland-Altman difference plot. Maltose (up to 13.9 mmol/L) and xylose (33.3 mmol/L) had no effect, but galactose (2.2 mmol/L) showed interference. The sugars also affected test strips for Advantage II but not Accutrend glucose meters. With International Organization for Standardization ISO 15197:2003 criteria, 99% of the 120 results determined by the test strips were within the minimal acceptable performance; only one of 106 (5.9 mmol/L) was >20% from the laboratory result.

CONCLUSIONS

The modified and improved Performa test strips were not affected by maltose and xylose. They meet ISO 15197:2003 requirements with a slight bias (-0.5 mmol/L) compared to the laboratory method.

False elevation of blood glucose levels measured by GDH-PQQ-based glucometers occurs during all daily dwells in peritoneal dialysis patients using icodextrin

OBJECTIVE

False elevation of blood glucose levels measured by glucose dehydrogenase pyrroloquinoline quinone (GDH-PQQ)-based glucose self-monitoring systems; glucometer) in peritoneal dialysis (PD) patients using icodextrin solution has been well documented. However, adverse hypoglycemic events caused by misreadings for blood glucose are still being reported. We aimed to study blood glucose levels measured simultaneously using different methods in PD patients with switching of icodextrin, and throughout daily exchanges either using icodextrin or not.

DESIGN

We recruited 100 PD patients, including 40 using icodextrin; 128 hemodialysis patients served as a reference. Fasting serum glucose was measured using our laboratory reference method (LAB) and 2 glucose self-monitoring systems based on glucose dehydrogenase nicotinamide adenine dinucleotide (GDH-NAD) and GDH-PQQ respectively. 80 PD patients had a second follow-up study. A time course study was performed in 16 PD patients through measuring fingertip glucose using the 2 glucose self-monitoring systems during daily exchanges.

RESULT

The differences in measured serum glucose levels in (PQQ minus LAB) versus (NAD minus LAB) were markedly increased in PD patients using icodextrin compared to other patient groups, and was further confirmed by the follow-up study in patients that switched to icodextrin. The high serum glucose levels measured by the GDH-PQQ-based glucose self-monitoring system were present throughout all exchanges during the day in patients using icodextrin solution.

CONCLUSION

False elevation of blood glucose measured by GDH-PQQ-based glucose self-monitoring systems exists in patients using icodextrin. To avoid misinterpretation of hyperglycemia and subsequent over-injection of insulin, GDH-PQQ-based glucose self-monitoring systems should not be used in PD patients.

[False capillary hyperglycaemia and true iatrogenic postoperative hypoglycaemia]

We describe a case-report of a 64-year-old woman who presented an acute iatrogenic hypoglycaemia after gynecological surgery. An inadequate keeping of Dextrostix led to wrong hyperglycaemia measurement and inappropriate insulin administration. The mistake was treated with complete recovery.

Analytical Interferences in Point-of-Care Testing Glucometers by Icodextrin and its Metabolites: An Overview

Current point-of-care testing (POCT) glucometers are based on various test principles. Two major method groups dominate the market: glucose oxidase-based systems and glucose dehydrogenase-based systems using pyrroloquinoline quinone (GDH-PQQ) as a cofactor. The GDH-PQQ-based glucometers are replacing the older glucose oxidase-based systems because of their lower sensitivity for oxygen. On the other hand, the GDH-PQQ test method results in falsely elevated blood glucose levels in peritoneal dialysis patients receiving solutions containing icodextrin ( e.g., Extraneal; Baxter, Brussels, Belgium). Icodextrin is metabolized in the systemic circulation into different glucose polymers, but mainly maltose, which interferes with the GDH-PQQ-based method. Clinicians should be aware of this analytical interference. The POCT glucometers based on the GDH-PQQ method should preferably not be used in this high-risk population and POCT glucose results inconsistent with clinical suspicion of hypoglycemic coma should be retested with another testing system.

Significant hypoglycemia secondary to icodextrin peritoneal dialysate in a diabetic patient

Icodextrin, a peritoneal dialysate commonly used in the renal failure patient with diabetes, may lead to an overestimation of blood glucose levels as determined by bedside glucometers. This spurious hyperglycemia can lead to significant morbidity if unrecognized. We describe a case of severe hypoglycemia caused by an unappreciated overestimation of blood glucose in a diabetic patient with concomitant chronic renal failure requiring peritoneal dialysis with icodextrin.

Occult hypoglycemia in a diabetic patient on peritoneal dialysis

In a patient with diabetes mellitus undergoing icodextrin continuous ambulatory peritoneal dialysis, the interference caused by icodextrin metabolites in bedside glucose analyzers led to an overestimation of capillary glucose levels and the potential for inappropriate therapy. We report this case to raise an awareness of this among emergency care providers who are at the front-line treating diabetes emergencies.