Acute kidney injury, stroke and death after cardiopulmonary bypass surgery: the role of perfusion flow and pressure.

INTRODUCTION: Acute kidney injury after cardiopulmonary bypass surgery is associated with morbidity and mortality. This study aims to evaluate the role of low perfusion flow and pressure in the development of cardiopulmonary bypass-associated acute kidney injury, stroke and death, using multicentre registry data. METHODS: We identified patients from the Australian and New Zealand Collaborative Perfusion Registry who underwent coronary artery bypass grafting and/or valvular surgery between 2008 and 2018. Primary predictor variables were the length of time the perfusion flow was <1.6 L/min/m2 and the length of time perfusion pressure was < 50mmHg. The primary outcome was new postoperative acute kidney injury defined by the risk-injury-failure-loss-end stage criteria. Secondary outcomes were stroke and in-hospital death. The influence of perfusion flow and pressure during cardiopulmonary bypass on the primary and secondary outcomes was estimated using separate multivariate models. RESULTS: A total of 16,356 patients were included. The mean age was 66 years and 75% were male. Acute kidney injury was observed in 1,844 patients (11%), stroke in 204 (1.3%) and in-hospital death in 286 (1.8%). Neither the duration of the time spent for perfusion flow (<1.6 L/minute/m2) nor the duration of the time spent for perfusion pressure (<50 mmHg) was associated with postoperative acute kidney injury, stroke or death in adjusted models. CONCLUSIONS: Neither low perfusion pressure nor low perfusion flow during cardiopulmonary bypass were predictive of postoperative acute kidney injury, stroke or death.

Infectious complications in the Southern Tasmanian kidney transplant population.

AIM: Examine the incidence of suspected and proven infections, the range of infections, antimicrobial use and hospital admissions in kidney transplant recipients (KTx) in southern Tasmania. METHODS: An audit of the medical records of KTx managed by the Royal Hobart Hospital for the period 1 January 2015 to 31 December 2016. Data were collected on positive microbiological investigations, antimicrobial use and hospital admissions. RESULTS: Of the 151 evaluable KTx, there were 339 episodes of suspected infection in 95 (63%) patients with a preponderance of urinary tract infections. Overall, these 95 KTx received a total of 249 courses of antimicrobials, with predominantly monotherapy (n = 101, 65%). There were 11 vaccine preventable infections, including herpes zoster (n = 7), Influenza A (n = 3) and invasive pneumococcal disease (n = 1). Hospitalization was required for 50 infectious episodes, for a total of 227 admitted bed days (median 4; interquartile range 2-7; range 1-18 days). CONCLUSION: In conclusion, episodes of infection, hospitalization, antimicrobial use and development of multi-resistant organisms are common following kidney transplantation in this southern Tasmanian cohort. This study has identified several areas of focus for improved patient care including antimicrobial management of urinary tract infections, implementation of programmes to vaccinate KTx prior to transplantation, and development of transplantation specific antimicrobial stewardship programmes.

Factors associated with chronic kidney disease progression in Australian nephrology practices.

BACKGROUND/AIMS: Chronic kidney disease (CKD) is a major health issue worldwide. The aim of this study was to explore factors associated with CKD progression in Australian nephrology practices. METHODS: This was a retrospective study utilising an electronic medical record (EMR), Audit4 (Software for Specialists, Australia). The baseline visit was defined as the first entry into the EMR. The primary outcome was the rate of change in estimated glomerular filtration rate (eGFR). RESULTS: 1,328 patients were included with a mean eGFR at baseline of 37.4 ± 0.7 ml/min/1.73 m(2), a mean follow-up of 17.7 months and a mean annual rate of change in eGFR of -0.84 ± 0.26 ml/min/1.73 m(2). Univariate analysis demonstrated that women, smokers, and patients prescribed erythropoiesis-stimulating agents (ESA) had a significantly more rapid decline in eGFR (p = 0.007, 0.033, and 0.003, respectively). On multivariate analysis: gender, age, prescription of ESA and phosphate binders, and baseline eGFR were significantly associated with CKD progression (p = 0.003, 0.004, <0.001, 0.029, and <0.001, respectively). CONCLUSIONS: This study identifies potential factors associated with CKD progression in a population referred to nephrologists, but current data quality may result in bias. Implementation of changes in the format of data collection is required so that busy clinicians record essential information to enable this to become a more accurate and reliable research tool.

Acute granulomatous interstitial nephritis in a patient with metastatic melanoma on targeted therapy with dabrafenib and trametinib-A case report.

BACKGROUND: Combination molecular targeted therapy with dabrafenib plus trametinib has been shown to improve progression-free survival and overall survival in patients with BRAF V600 mutated unresectable or metastatic melanoma. In general, these agents are well tolerated. Kidney related adverse events are uncommon with only three case reports of acute interstitial nephritis and one case of a serious acute kidney injury. We report another case of interstitial nephritis related to these drugs. CASE: A 37-year-old man diagnosed with metastatic melanoma (BRAF V600E mutation) who developed acute interstitial nephritis 5 years into his treatment with combination dabrafenib plus trametinib therapy. He presented with an asymptomatic acute kidney injury on routine surveillance pathology with a creatinine of 174 µmol/L (from baseline 80 µmol/L) and a corresponding estimated glomerular filtration rate (eGFR) of 42 ml/min/1.73 m2 (from a baseline >90 ml/min/1.73 m2 ) and microalbuminuria (albumin creatinine ratio [ACR] 8.5 mg/mmol). Renal biopsy revealed a granulomatous interstitial nephritis likely drug related. He was treated with prednisolone 1 mg/kg and ceased his targeted therapy with improvement in his renal function. CONCLUSION: Although rare, recognition of acute interstitial nephritis, a possible serious adverse outcome due to dabrafenib and trametinib is important and needs to be incorporated into current Australian cancer therapy guidelines.

Chronic kidney disease in Tasmania.

AIM: Chronic kidney disease (CKD) is a progressive disease which is becoming a major public health issue due to its high rate of premature death, poor quality of life and expensive end-stage treatment (dialysis or transplantation). The burden of this chronic condition in a community setting was examined. METHODS: Data were obtained from 369,098 Tasmanian adults (aged >or=18 years) and included 1,640,687 measurements of creatinine taken between 1995 and 2007. In 2007 alone, testing comprised 25.5% of the state's adult population. A modelled estimate of CKD prevalence was developed. RESULTS: For those at risk of CKD (aged >50 years), 50.6%, 70.2% and 82% had a measured creatinine (and reported estimated glomerular filtration rate (eGFR)) during the last 1, 2 and 3 years respectively. However, only 9.4% of people with eGFR of less than 60 mL/min per 1.73 m(2) had albuminuria formally measured. Estimated prevalence of stage III or greater CKD (eGFR <60 mL/min per 1.73 m(2)) was at least 11.4% of women and 8.6% of men during 2007. Detection of low eGFR increased significantly over the last 13 years. There was a large geographic variation throughout Tasmania and high relative mortality with lower eGFR. There is a broad gap between the number of people with eGFR of less than 15 mL/min per 1.73 m(2) (stage V CKD) and those receiving dialysis treatment. CONCLUSION: The number of people identified with low eGFR has increased significantly since 1995 with a large geographic variation. Despite this, testing for kidney disease (by measuring serum creatinine and albuminuria) in people at risk is still suboptimal.

Darbepoetin alfa administered monthly maintains haemoglobin concentrations in patients with chronic kidney disease not receiving dialysis: a multicentre, open-label, Australian study.

AIM: Darbepoetin alfa, an erythropoiesis-stimulating protein, has a longer serum half-life than recombinant human erythropoietin, allowing less-frequent administration. This study aimed to demonstrate that once-monthly (QM) darbepoetin alfa administration would maintain haemoglobin (Hb) concentrations in subjects with chronic kidney disease (CKD) not receiving dialysis who had previously been administered darbepoetin alfa every 2 weeks (Q2W). METHODS: This was a multicentre study in which subjects with CKD receiving stable Q2W darbepoetin alfa doses and with stable Hb (100-130 g/L) were started on QM darbepoetin alfa dosing. The initial QM darbepoetin alfa dose was equivalent to the cumulative darbepoetin alfa dose administered during the month preceding enrollment. Darbepoetin alfa doses were titrated to maintain Hb concentrations between 100 and 130 g/L. The primary endpoint was the proportion of subjects maintaining mean Hb >or= 100 g/L during the evaluation period (weeks 21-33). RESULTS: Sixty-six subjects were enrolled in the study and all received at least one dose of darbepoetin alfa; 55 (83%) had mean Hb >or= 100 g/L during evaluation. Mean (SD) Hb concentrations at baseline and during the evaluation period were 119 (8.7) g/L and 114 (9.8) g/L, respectively. The median QM darbepoetin alfa dose at baseline and during the evaluation period was 80 microg. Darbepoetin alfa was considered to be well-tolerated. CONCLUSION: Patients with CKD not receiving dialysis who are receiving darbepoetin alfa Q2W can be safely and effectively extended to darbepoetin alfa QM. Dosing QM may simplify anaemia management for patients and health-care providers.