Metformin-Associated Lactic Acidosis Undergoing Renal Replacement Therapy in Intensive Care Units: A Five-Million Population-Based Study in the North-West of Italy.

BACKGROUND: Metformin-associated lactic acidosis (MALA) is a severe complication of drug administration with significant morbidity and mortality. So far no study in large population areas have examined the incidence, clinical profile and outcome of acute kidney injury (AKI)-MALA patients admitted in intensive care units (ICUs) and treated by renal replacement therapy (MALA-RRT). METHODS: Retrospective analysis over a 6-year period (2010-2015) in Piedmont and Aosta Valley regions (5,305,940 inhabitants, 141,174 diabetics treated with metformin) of all MALA-RRT cases. RESULTS: One hundred and seventeen cases of AKI-MALA-RRT were observed (12.04/100,000 metformin treated diabetics, 1.45% of all RRT-ICU patients). Survival rate was 78.3%. The average duration of RRT was 4.0 days at mean dialysis effluent of 977 mL/kg/day. At admission most patients were dehydrated, and experienced shock and oliguria. CONCLUSION: Our data showed that MALA-RRT is a common complication, needing more prevention. Adopted policy of early, extended, continuous and high efficiency dialysis could contribute to an observed high survival rate. Video Journal Club "Cappuccino with Claudio Ronco" at http://www.karger.com/?doi=471917.

Severe cortical and trabecular osteopenia in secondary hyperparathyroidism.

BACKGROUND: Peripheral quantitative computed tomography (pQCT) provides real volumetric bone density values, not only of the total, but also of trabecular and cortical bone, separately. In addition, it provides data on bone geometry that can be related to the risk of fracture. METHODS: Total, cortical, and trabecular volumetric bone mineral densities (BMD), as well as the main geometric parameters (cross-sectional area, cortical area, trabecular area, and cortical thickness) were assessed by pQCT at the distal radius in 24 hemodialysis patients affected by severe secondary hyperparathyroidism (PTH, mean +/- SD: 1444 +/- 695 pg/mL). The strength-strain index (SSI), a biomechanical parameter describing bone fragility, was also determined. RESULTS: Compared with a control group of 64 healthy age-matched subjects, volumetric BMD (mg/cm(3)) was significantly reduced in all patients (total BMD: 243 +/- 87 vs. 405 +/- 138, cortical BMD: 605 +/- 218 vs. 856 +/- 204, trabecular BMD: 95 +/- 51 vs. 182 +/- 75). Cortical area and cortical thickness showed significant modifications, while cross-sectional area did not. SSI was significantly reduced (547 +/- 125 vs. 927 +/- 306 mm(3)). PTH levels showed a significant inverse correlation with cortical BMD (r = -0.56), cortical thickness (r = -0.46), cortical area (r = -0.61), and SSI (r = -0.54). Quantitative analysis of bone demonstrated cortical porosity. CONCLUSIONS: In dialysis patients with severe secondary hyperparathyroidism, pQCT showed a significant cortical osteopenia, associated with geometric and mechanical bone impairment. Interestingly, we also found a comparable deficit of trabecular bone, which may be related to the very high PTH levels. Generalized cortical thinning, intracortical porosity and cortical-endosteal resorption ("trabecularization" of the cortical bone) are major determinants of reduced bone strength, which may be quantitated by pQCT.