Beta-2 microglobulin clearance in high-flux dialysis and convective dialysis modalities: a meta-analysis of published studies.

Background: Recent meta-analyses suggest that higher removal of beta-2 microglobulin (ß2M) with either high-flux (HFD) dialysis or hemodiafiltration (HDF) may be associated with decreased total and cardiovascular mortality in dialysis patients. However, there are limited data about the performance of high flux dialyzers and/or convective therapies in removing ß2M. Methods: This is a random effects meta-analysis and meta-regression of data extracted from randomized controlled trials and observational studies in hemodialysis, hemofiltration and HDF regarding the efficiency of high flux dialyzers to remove ß2M. Studies were searched using ProQuest in SCOPUS, EMBASE and MEDLINE. Results: We included 69 studies from 1 January 2001 to 12 June 2017 on 1879 patients with 6771 available measurements. Average ß2M clearance was 48.75 mL/min [95% confidence interval (CI) 42.50-55.21] for conventional HF dialysis, and 87.06 mL/min (95% CI 75.08-99.03) for convective therapies (hemofiltration and HDF) with substantial heterogeneity among studies [P (Q) ≤ 0.001]. In multivariable meta-regression analyses, we found significantly higher ß2M clearance for polyarylethersulfone dialyzers when used for HFD and polysulfone membranes in convective therapies. However, the mass of ß2M removed into the dialysate did not depend on membrane material. Adjusted dialysate-side (-22.279, 95% CI -9.8 to -34.757, P < 0.001) ß2M clearances were significantly lower than whole blood clearances, suggesting that adsorption contributes substantially to ß2M removal. Higher Kuf, blood flow and substitution fluid rates but not dialysate flow rates were associated with statistically significant and clinically meaningful elevation in ß2M clearance from the body independent of the dialysis modality. Conclusions: Membrane composition and characteristics, modality (convective versus diffusive), blood flow rates and substitution fluid rates in HDF play a significant role in the efficient removal of ß2M from the body in both diffusive and convective dialysis.

Establishing the presence or absence of chronic kidney disease: Uses and limitations of formulas estimating the glomerular filtration rate.

The development of formulas estimating glomerular filtration rate (eGFR) from serum creatinine and cystatin C and accounting for certain variables affecting the production rate of these biomarkers, including ethnicity, gender and age, has led to the current scheme of diagnosing and staging chronic kidney disease (CKD), which is based on eGFR values and albuminuria. This scheme has been applied extensively in various populations and has led to the current estimates of prevalence of CKD. In addition, this scheme is applied in clinical studies evaluating the risks of CKD and the efficacy of various interventions directed towards improving its course. Disagreements between creatinine-based and cystatin-based eGFR values and between eGFR values and measured GFR have been reported in various cohorts. These disagreements are the consequence of variations in the rate of production and in factors, other than GFR, affecting the rate of removal of creatinine and cystatin C. The disagreements create limitations for all eGFR formulas developed so far. The main limitations are low sensitivity in detecting early CKD in several subjects, e.g., those with hyperfiltration, and poor prediction of the course of CKD. Research efforts in CKD are currently directed towards identification of biomarkers that are better indices of GFR than the current biomarkers and, particularly, biomarkers of early renal tissue injury.

Near death by milk of magnesia.

We report a case of hypermagnesemia associated with the use of milk of magnesia in a male patient with end-stage renal disease. After experiencing nausea and vomiting, he developed severe bradycardia and then asystole. Resuscitation efforts were successful; however, he developed atrial fibrillation with severe widening of the QRS and diffuse ST elevation, hypothermia, hypotension and apnoea requiring intubation. Initial diagnoses included ST-elevation myocardial infarction, cardiogenic and/or septic shock and hyperkalaemia. However, serum magnesium was later found to be >4.1 mmol/L (equivalent to >10 mg/dL). He underwent haemodialysis (HD) to remove serum magnesium with remarkable overall improvement. Severe hypermagnesemia can manifest with severe bradycardia and asystole, shock, hypothermia and respiratory failure and can mimic acute coronary syndromes complicated with cardiogenic shock or septic shock. Therefore, clinicians should be aware of this life-threatening condition in patients with significant renal dysfunction. Timely treatment with HD is highly effective and lifesaving.

Epidemiological features of Clostridium difficile infection among inpatients at Hamad General Hospital in the state of Qatar, 2006-2009.

The aim of this retrospective study was to evaluate the epidemiology, clinical course and outcome of Clostridium difficile infection among inpatients at Hamad General Hospital in Qatar, from 2006 to 2009. During this period, 123 patients were diagnosed with C. difficile infection and the overall incidence was 1.6/10,000 patient days. The mean age (±SD) of patients was 50.9 ± 21.2 years. The most frequent underlying disease was hypertension 51/123 (41.5%) and 133 prescriptions of antimicrobials were ordered for 105/123 (86.1%) patients prior to C. difficile infection with piperacillin-tazobactam being the most frequently prescribed antimicrobial 39/131 (29.7%). Nosocomial infection was found in 101/123 (82.0%) of cases, and the most common clinical feature was watery diarrhoea 119/123 (96.7%). Antimicrobials were discontinued in 53/105 (50.5%) cases and 118/123 (95.9%) of them received metronidazole as the initial treatment. The mean treatment duration (±SD) was 9.08 ± 5.6 days. Fifteen (12.7%) patients failed the first course of antimicrobial therapy, of which four were treated with oral vancomycin, and eleven patients received both drugs. Recurrence of infection was observed in 12/118 (10.2%) patients and 30-day mortality was 38/123 (30.9%). Several clinical variables were associated with increased 30-day mortality on univariate analysis. Only occurrence of disease among Qataris, prolonged hospitalisation, positive stool occult blood test, high white blood cells and septic shock were found to be independent predictors of mortality by multivariate logistic regression analysis. In conclusion, C. difficile infection was a recognise cause of morbidity and mortality in our hospital with low and stable incidence. It involved predominantly patients younger than 65 years with underlying illness and metronidazole and vancomycin were effective in resolving symptoms in the majority of our patients.