Bedside detection of urine beta-hydroxybutyrate in diagnosing metabolic acidosis

Clinicopathologic Appearance of Advanced Ketoacidosis With Basal Vacuolation in Renal Tubules

CONTEXT.—

Basal vacuolization (BV) in renal tubules is a histopathologic hallmark of advanced ketoacidosis that enables us to retrospectively diagnose these cases.

OBJECTIVE.—

To clarify the pathologic background and serologic findings of ketoacidosis with BV, and to reveal the pathologic findings by each pathologic background.

DESIGN.—

We examined 664 serial autopsy cases. A systemic histopathologic examination and measurement of serum β-hydroxybutyrate concentration were performed for the cases with BV. The extent of steatosis and fibrosis in the organs and the degree of coronary artery stenosis were semiquantitatively investigated. Immunohistochemistry for adipophilin was also performed to analyze its usefulness for the pathologic diagnosis.

RESULTS.—

Basal vacuolization was found in 16 cases, all of which showed a pathologic serum β-hydroxybutyrate concentration. The main background of ketoacidosis was considered as alcohol abuse in 6 cases, diabetes in 5, malnutrition in 3, and hypothermia and infection in 1 case each. Severe hepatic fibrosis was observed only in the alcohol-abuser group. Moreover, cardiac steatosis was more severe in patients with possible alcohol abuse than in those with other causes. Immunohistochemistry for adipophilin showed immunoreactivity consistent with BV in 13 of 16 cases. There was no correlation between β-hydroxybutyrate concentration and either the postmortem or storage interval.

CONCLUSIONS.—

Basal vacuolization may be a useful finding for detecting ketoacidosis cases in a postmortem investigation. Serum β-hydroxybutyrate was a stable and reliable compound for the definitive diagnosis of ketoacidosis in such cases. The present study showed that pathologic changes in some organs may vary by each pathologic background of ketoacidosis with BV.

The burden of diabetic emergencies on the resuscitation area of a district-level public hospital in Cape Town

INTRODUCTION

Diabetes and its complications continue to cause a daunting and growing concern on resource-limited environments. There is a paucity of data relating to the care of diabetic emergencies in the emergency centres of entry-level hospitals in Africa. The aim of this study was to describe the burden of diabetic emergencies presenting to the emergency centre of an urban district-level hospital in Cape Town, South Africa.

METHODS

The Khayelitsha Hospital Emergency Centre database was retrospectively analysed for patients presenting with a diabetic emergency within a 24-week randomly selected period. The database was supplemented by a retrospective chart review to include additional variables for participants with diabetic ketoacidosis (DKA), uncomplicated hyperglycaemia, severe hypoglycaemia and hyperosmolar hyperglycaemic state (HHS). Summary statistics are presented of all variables.

RESULTS

The prevalence of all diabetic emergencies was 8.1% (197/2424) (DKA n = 96, 48.7%; uncomplicated hyperglycaemia n = 45, 22.8%; severe hypoglycaemia n = 44, 22.3%; HHS n = 12, 6%). The median age was 48 years, with those presenting with DKA being substantially younger (36 years). A likely precipitant was identified in 175 (88%) patients; infection was the most common precipitant (n = 79, 40.1%). Acute kidney injury occurred in 80 (40.6%) cases. The median length of stay in the resuscitation area was 13 h (IQR 7.2-24) and 101 (51.3%) participants represented with a diabetic- related emergency within six months of the study period. The overall mortality rate was 5% (n = 10).

CONCLUSION

This study highlights the high burden of diabetic emergencies on the provision of acute care at a district-level hospital. The high prevalence of diabetic emergencies (8%) consisted of DKA (48.7%), uncomplicated hyperglycaemia (22.8%), severe hypoglycaemia (22.3%), and HHS (6%). The high infection rate (40%) and the high percentage of patients returning with a diabetic emergency (51%) could be indicative of the need for improved community-based diabetic programmes.

Effect of short-term ketogenic diet on end-tidal carbon dioxide

BACKGROUND & AIMS

Previous studies have shown that end-tidal carbon dioxide (EtCO₂) is lower with the presence of supraphysiological ketones as in the case of chronic ketogenic diet (KD) and diabetic ketoacidosis (DKA). This study aimed to determine changes in EtCO₂ upon short term KD.

METHODS

Healthy subjects were screened not to have conditions that exerts abnormal EtCO₂ nor contraindicated for KD. Subjects underwent seven days of KD while the EtCO2 and blood ketone (beta-hydroxybutyrate; β-OHB) parameters were sampled at day zero (t0) and seven (t7) of ketosis respectively. Statistically, the t-test and Pearson's coefficient were conducted to determine the changes and correlation of both parameters.

RESULTS

12 subjects completed the study. The mean score ± standard deviation (SD) for EtCO₂ were 35.08 ± 3.53 and 35.67 ± 3.31 mm Hg for t0 and t7 respectively. The mean score ±SD for β-OHB were 0.07 ± 0.08 and 0.87 ± 0.84 mmol/L for t0 and t7 respectively. There was no significant difference of EtCO₂ between the period of study (p > 0.05) but the β-OHB increased during t7 (p < 0.05). There was also no correlation between the parameters.

CONCLUSIONS

These findings suggest that EtCO₂ may not be utilized to determine short term nutritional ketosis.

Breath Acetone Measurement-Based Prediction of Exercise-Induced Energy and Substrate Expenditure

The purpose of our study was to validate a newly developed breath acetone (BrAce) analyzer, and to explore if BrAce could predict aerobic exercise-related substrate use. Six healthy men ran on a treadmill at 70% of maximal oxygen consumption (VO_2max) for 1 h after two days of a low-carbohydrate diet. BrAce and blood ketone (acetoacetate (ACAC), beta-hydroxybutyrate (BOHB)) levels were measured at baseline and at different time points of post-exercise. BrAce values were validated against blood ketones and respiratory exchange ratio (RER). Our results showed that BrAce was moderately correlated with BOHB (r = 0.68, p < 0.01), ACAC (r = 0.37, p < 0.01) and blood ketone (r = 0.60, p < 0.01), suggesting that BrAce reflect blood ketone levels, which increase when fat is oxidized. Furthermore, BrAce also negatively correlated with RER (r = 0.67, p < 0.01). In our multiple regression analyses, we found that when BMI and VO_2max were added to the prediction model in addition to BrAce, R² values increased up to 0.972 at rest and 0.917 at 1 h after exercise. In conclusion, BrAce level measurements of our BrAce analyzer reflect blood ketone levels and the device could potentially predict fat oxidation.

Point-of-Care Glucose and Ketone Monitoring

Early and rapid identification of hypo- and hyperglycemia as well as ketosis is essential for the practicing veterinarian as these conditions can be life threatening and require emergent treatment. Point-of-care testing for both glucose and ketone is available for clinical use and it is important for the veterinarian to understand the limitations and potential sources of error with these tests. This article discusses the devices used to monitor blood glucose including portable blood glucose meters, point-of-care blood gas analyzers and continuous glucose monitoring systems. Ketone monitoring options discussed include the nitroprusside reagent test strips and the 3-β-hydroxybutyrate ketone meter.

Recent and potential developments in the analysis of urine: a review

Analysis of urine is a widely used diagnostic tool that traditionally measured one or, at most, a few metabolites. However, the recognition of the need for a holistic approach to metabolism led to the application of metabolomics to urine for disease diagnostics. This review looks at various aspects of urinalysis including sampling and traditional approaches before reviewing recent developments using metabolomics. Spectrometric approaches are covered briefly since there are already a number of very good reviews on NMR spectroscopy and mass spectrometry and other spectrometries are not as highly developed in their applications to metabolomics. On the other hand, there has been a recent surge in chromatographic applications dedicated to characterising the human urinary metabolome. While developments in the analysis of urine encompassing both classical approaches of urinalysis and metabolomics are covered, it must be emphasized that these approaches are not orthogonal - they both have their uses and are complementary. Regardless, the need to normalise analytical data remains an important impediment.

New automated and high-throughput quantitative analysis of urinary ketones by multifiber exchange-solid phase microextraction coupled to fast gas chromatography/negative chemical-electron ionization/mass spectrometry

The present research is focused on automation, miniaturization, and system interaction with high throughput for multiple and specific Direct Immersion-Solid Phase Microextraction/Fast Gas Chromatography analysis of the urinary ketones. The specific Mass Spectrometry instrumentation, capable of supporting such the automated changeover from Negative Chemical to Electron Ionization mode, as well as the automation of the preparation procedure by new device called MultiFiber Exchange, through change of the fibers, allowed a friendly use of mass spectrometry apparatus with a number of advantages including reduced analyst time and greater reproducibility (2.01-5.32%). The detection limits for the seven ketones were less than 0.004 mg/L. For an innovative powerful meaning in high-throughput routine, the generality of the structurally informative Mass Spectrometry fragmentation patterns together with the chromatographic separation and software automation are also investigated.