Comparison of BACTEC versus conventional enrichment medium for peritoneal dialysate fluid culture.

BACKGROUND: Bacterial peritonitis remains a significant cause of mortality in patients on peritoneal dialysis (PD). Early detection of causative organisms and targeted antimicrobial treatment allow for better clinical outcomes. This study compares bacterial growth results from peritoneal dialysate in the BACTEC blood culture system vs. conventional culture. MATERIALS AND METHODS: We conducted a prospective study on 46 patients with 63 consecutive episodes of suspected PD peritonitis between August 2020 and August 2021. PD dialysate was simultaneously sent to the laboratory in both BACTEC and sterile bottles. BACTEC bottles were incubated in the BD BACTEC FX system for 5 days. PD effluent transported from the sterile bottles was centrifuged at 3,000 rpm for 15 minutes; the supernatant was inoculated into cooked-meat broth for enrichment. Both incubation methods were extended to 14 days if microorganisms were seen on the Gram-stained smear. Recovery of isolated micro-organisms and time to detection (TTD) were compared. RESULTS: 26 episodes of suspected PD peritonitis based on clinical criteria were identified during the study period. The sensitivity of the BACTEC and the conventional culture methods was 50% and 42.3%, respectively (p = 0.45). Seven samples had partial concordance or discordant results. McNemar's χ2-test revealed no statistical difference between either method (p = 0.45). TTD was 18.9 ± 24.4 hours via the BACTEC method vs. 37 ± 16.5 hours in conventional cultures (p = 0.014). CONCLUSION: The comparable sensitivities and similar yield in identifying pathogens could be due to the enrichment medium and prolonged incubation period. The shorter TTD for the BACTEC method could facilitate earlier confirmation of bacteriological diagnosis and subsequent treatment strategies.

Handheld ultrasound-guided cannulation of difficult hemodialysis arteriovenous access: A randomized controlled trial.

INTRODUCTION: Cannulation of complex arteriovenous fistula (AVF) or graft (AVG) frequently poses challenges to renal nursing practice. Ultrasound (US) guidance on visualizing central and peripheral venous access has been widely adopted in nephrology, reducing vascular intervention complications. Renal nurses could acquire this point-of-care technique to increase the successful cannulation rate while facilitating confidence build-up during practice. We aim to evaluate the use of handheld US on difficult AVF/AVG cannulation in a hospital-based dialysis unit. METHODS: We conducted a single-center randomized controlled trial from January 2021 to January 2022. Ten renal nurses were trained by an interventional nephrologist before patient recruitment and had completed a pre- and posttraining questionnaire on their confidence level. Fifty hemodialysis patients with complex AVF were randomized to US-guided or conventional cannulation. The total time spent on cannulation and patients' pain scores were also collected. FINDINGS: Renal nurses increased their confidence level after training (pretraining score 26.6 ± 6.9 vs. posttraining score 36.4 ± 3.0; p = 0.014). There was a higher success rate (only one cannulation attempt required) for US-guided (96%) versus conventional (72.0%) cannulation (p = 0.049). US-guided cannulation had a lower pain score than the conventional method (1.48 ± 0.73 vs. 2.13 ± 0.95, p = 0.012). The pre-cannulation assessment time and time spent on cannulation were comparable between the two groups. DISCUSSION: Our study showed that US-guided cannulation increased renal nurses' confidence level in difficult cannulation and improved success rate. Larger scale studies are required to further assess the applications of handheld US in AVF cannulation, particularly in different clinical settings (e.g., chronic dialysis centers).

Automated lung ultrasound image assessment using artificial intelligence to identify fluid overload in dialysis patients.

BACKGROUND: Fluid assessment is challenging, and fluid overload poses a significant problem among dialysis patients, with pulmonary oedema being the most serious consequence. Our study aims to develop a simple objective fluid assessment strategy using lung ultrasound (LUS) and artificial intelligence (AI) to assess the fluid status of dialysis patients. METHODS: This was a single-centre study of 76 hemodialysis and peritoneal dialysis patients carried out between July 2020 to May 2022. The fluid status of dialysis patients was assessed via a simplified 8-point LUS method using a portable handheld ultrasound device (HHUSD), clinical examination and bioimpedance analysis (BIA). The primary outcome was the performance of 8-point LUS using a portable HHUSD in diagnosing fluid overload compared to physical examination and BIA. The secondary outcome was to develop and validate a novel AI software program to quantify B-line count and assess the fluid status of dialysis patients. RESULTS: Our study showed a moderate correlation between LUS B-line count and fluid overload assessed by clinical examination (r = 0.475, p < 0.001) and BIA (r = 0.356. p < 0.001). The use of AI to detect B-lines on LUS in our study for dialysis patients was shown to have good agreement with LUS B lines observed by physicians; (r = 0.825, p < 0.001) for the training dataset and (r = 0.844, p < 0.001) for the validation dataset. CONCLUSION: Our study confirms that 8-point LUS using HHUSD, with AI-based detection of B lines, can provide clinically useful information on the assessment of hydration status and diagnosis of fluid overload for dialysis patients in a user-friendly and time-efficient way.

A real-world study on SGLT2 inhibitors and diabetic kidney disease progression.

Background: Randomized controlled trials have demonstrated the benefits of sodium-glucose cotransporter 2 inhibitors (SGLT2is) in people with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD). However, real-world data on CKD progression and the development of end-stage kidney disease (ESKD) remains scarce. Our aim was to study renal outcomes of people with diabetic kidney disease (DKD) using SGLT2is in a highly prevalent DKD population. Methods: Between 2016 and 2019 we recruited T2DM patients in the renal and diabetic clinics in a regional hospital in Singapore. Patients prescribed SGLT2is were compared with those on standard anti-diabetic and renoprotective treatment. The outcome measures were CKD progression [a ≥25% decrease from baseline and worsening of estimated glomerular filtration rate (eGFR) categories according to the Kidney Disease: Improving Global Outcomes guidelines] and ESKD (eGFR <15 mL/min/1.73 m2). Results: We analysed a total of 4446 subjects; 1598 were on SGLT2is. There was a significant reduction in CKD progression {hazard ratio [HR] 0.60 [95% confidence interval (CI) 0.49-0.74]} with SGLT2is. The HR for eGFR ≥45 mL/min/1.73 m2 and 15-44 mL/min/1.73 m2 was 0.60 (95% CI 0.47-0.76) and 0.43 (95% CI 0.23-0.66), respectively. There was also a reduction in risk for developing ESKD for the entire cohort [HR 0.33 (95% CI 0.17-0.65)] and eGFR 15-44 mL/min/1.73 m2 [HR 0.24 (95% CI 0.09-0.66)]. Compared with canagliflozin and dapagliflozin, empagliflozin showed a sustained risk reduction of renal outcomes across CKD stages 1-4. Conclusions: This real-world study demonstrates the benefits of SGLT2is on CKD progression and ESKD. The effect is more pronounced in moderate to advanced CKD patients.

Association of overhydration and serum pigment epithelium-derived factor with CKD progression in diabetic kidney disease: A prospective cohort study.

AIM: Little is known about whether overhydration (OH), measured using bioimpedance assay (BIA), is associated with CKD progression in patients with type 2 diabetes mellitus (T2DM). We hypothesised that OH was a predictor, and pigment epithelium-derived factor (PEDF) was a modifiable risk factor of CKD progression. METHODS: We conducted a prospective cohort study of 1,065 patients with clinically euvolemic T2DM who attended the diabetes centre in a tertiary hospital or primary care clinic. CKD progression was defined as a combination of the worsening of the KDIGO defined CKD category by eGFR and a ≥25% decline in eGFR compared to baseline. RESULTS: Patients with T2DM in the highest tertile of OH and relative OH (OH/ extracellular water > 7%) were positively associated with CKD progression (hazard ratio [HR] 1.45 [95% confidence interval (CI) 1.14-1.85; p = 0.003 and HR 1.29 [95%CI 1.05-1.59; p = 0.017]). There were positive associations between PEDF and CKD progression (ß = 1.10; p = 0.001) and between OH and CKD progression (ß = 0.21; p = 0.036). OH remained positively associated with CKD progression mediated by PEDF. CONCLUSIONS: OH is an independent risk factor for CKD progression in patients with T2DM. Our study supports the novel definition of PEDF as a positive mediator between OH and CKD progression.

Low, rather than High, Body Mass Index Is a Risk Factor for Acute Kidney Injury in Multiethnic Asian Patients: A Retrospective Observational Study.

BACKGROUND: Acute kidney injury (AKI) is common in hospitalised patients. The relationship between body mass index (BMI) and the risk of having AKI for patients in the acute hospital setting is not known, particularly in the Asian population. METHODS: This was a retrospective, single-centre, observational study conducted in Singapore, a multiethnic population. All patients aged ≥21 years and hospitalised from January to December 2013 were recruited. RESULTS: A total of 12,555 patients were eligible for the analysis. A BMI of <18.5 kg/m2 was independently associated with the development of AKI in hospitalised patients (odds ratio (OR): 1.23 [95% confidence interval [CI]: 1.04-1.44, P = 0.01]) but not for overweight and obesity. Subgroup analysis further revealed that underweight patients aged ≥75 and repeated hospitalisation posed a higher risk of AKI (OR: 1.25 [CI: 1.01-1.56], P = 0.04; OR: 1.23 [CI: 1.04-1.44], P = 0.01, resp.). Analyses by interactions between different age groups and BMI using continuous or categorised variables did not affect the overall probability of developing AKI. CONCLUSIONS: Underweight Asian patients are susceptible to AKI in acute hospital settings. Identification of this novel risk factor for AKI allows us to optimise patient care by prevention, early detection, and timely intervention.

Outcomes of a nephrologist-driven tunnelled dialysis catheter insertion service in South East Asia.

INTRODUCTION: Tunnelled dialysis catheters (TDCs) are being increasingly inserted by nephrologists globally but there is limited experience and paucity of published outcomes data from South-East Asia (SEA). This study was conducted to analyse the outcomes of TDC insertion by nephrologists from a single centre in SEA. METHODS: All patients who underwent TDC insertion by nephrologists from October 2013 to June 2016 were included. TDC survival was calculated using Kaplan-Meier survival method. Impact of variables was assessed using Cox proportional hazards model. RESULTS: A total of 344 TDCs were inserted in 274 patients. The most common indication was haemodialysis initiation (60.2%) followed by existing catheter dysfunction (CD) (12.2%), failed vascular access (10.2%) and catheter-related bacteraemia (CRB) (9.9%). Insertion was successful in 97% patients. The most common location was the right internal jugular vein (87%). The cumulative survival for all TDCs inserted, as defined by the time to non-elective removal of a TDC, at 3, 6 and 9 months was 83%, 61%, and 44%, respectively. Median catheter survival was 231 days. Common indications for removal were CD (13.4%) and CRB or suspected infection (12.5%). Common complications were bleeding (8.72%), infection (13.7%) and CD (16.5%). Median time to infection was 103 days. In multivariate analysis, male gender was associated with poor catheter survival, for primary insertions (p = 0.015, HR 0.62) and diabetes was associated with TDC infection (p = 0.024, OR 1.1). CONCLUSIONS: This is one of the first reports of TDC insertion by nephrologists from SEA. Our outcomes compare favourably with those reported in the literature.

A veno-caliceal fistula related to ureteric stricture in a kidney allograft masquerading as renal failure.

We report an unusual case of veno-caliceal fistula that developed because of high ureteric pressure caused by graft ureteric stricture after kidney transplantation in a 60-year-old patient. We further confirmed its presence with radiological images. Recirculation of creatinine and other uremic toxins resulted in a biochemical picture of renal failure in the presence of normal kidney function, confirmed by normal scintigraphy findings. Drainage of the pelvi-caliceal system could not be assessed accurately by means of diuretic renogram using technetium-99m diethylenetriaminepentaacetic acid with frusemide because of the rapid clearance of tracer activity from the system in the presence of a veno-caliceal fistula. The patient's renal function improved rapidly after interrupting urine recirculation by using percutaneous drainage, confirming "pseudo renal failure" as the cause of his persistently increased serum creatinine concentration. The ureter was re-implanted later, and the veno-caliceal fistula was not seen in the nephrostogram after the operation. He remains well with stable renal function at 3 years' follow-up. Clinicians should exercise judgment when evaluating patients with allograft dysfunction, especially when the investigation and clinical findings show contradicting results.