High diagnostic performance of CT scan for analgesic nephropathy in patients with incipient to severe renal failure.

Recently, well performing diagnostic criteria for analgesic nephropathy in end-stage renal failure (ESRF) patients were defined by the demonstration of a bilateral decrease in renal volume combined with either bumpy contours or papillary calcifications. In this study, the diagnostic value of computed tomography (CT) scan was compared to the previously used renal imaging techniques (sonography and conventional tomography). In a first study, a cohort of 40 analgesic abusers (defined as daily use of analgesic mixtures during at least 5 years) and 40 controls, all ESRF patients without a clear renal diagnosis, were investigated with sonography, tomography and CT scan without injection of iodinated contrast material, to search for the imaging signs of analgesic nephropathy. Using CT scan, sonography and tomography, renal size could be evaluated with comparable results while CT scan was superior in the detection of papillary calcifications (sensitivity 87%, specificity 97%). In a second controlled study of 53 analgesic abusers with a serum creatinine between 1.5 to 4 mg/dl in the absence of a clear renal diagnosis, a CT scan was performed and scored for the presence of decreased renal volume, bumpy contours and papillary calcifications. It was found that the renal image of analgesic nephropathy on CT scan in an early stage of renal failure is comparable with the observations made in ESRF patients. Particularly the demonstration of papillary calcifications showed a high sensitivity of 92% with a specificity of 100% for the early diagnosis of analgesic nephropathy.

Diagnostic criteria of analgesic nephropathy in patients with end-stage renal failure: results of the Belgian study.

Diagnostic criteria of analgesic nephropathy with well-defined sensitivity and specificity are not available. During a 2-year period all new patients (n = 273) starting renal replacement therapy in 13 Belgian dialysis units were investigated aiming to select diagnostic criteria of analgesic nephropathy with acceptable performance. Using several interview techniques, a history of analgesic abuse was found in 31% of the patients. Analgesic abusers presenting a clear non-analgesic-related renal diagnosis were excluded from analysis (n = 25). Comparing the remaining abusers (n = 60) and patients without a history of analgesic abuse (n = 188) it was found that renal imaging investigations (sonography plus tomography), showing a decrease in length combined with bumpy contours of both kidneys, presented a sensitivity of 90% and a specificity of 95%. The additional finding of signs of renal papillary necrosis resulted in an overall sensitivity of 72% and a specificity of 97%, giving a positive predictive value of 92%. Other signs frequently mentioned in the literature (hypertension, anaemia, sterile pyuria, bacteriuria, proteinuria) showed insufficient sensitivity and/or specificity to be of help for diagnosing analgesic nephropathy in end-stage renal failure (ESRF) patients starting renal replacement therapy.

[Hypokalemia with rhabdomyolysis secondary to chronic small bowel obstruction]. / Hypokaliëmie met rhabdomyolysis, secundair aan chronische dundarmsubobstructie.

Rhabdomyolysis, secondary to chronic small bowel obstruction. The authors report the case of a 48-year old man, who developed rhabdomyolysis based only upon hypokalemia secondary to a chronic gastro-intestinal disorder (chronic obstruction of the small bowel). They would like to point out that despite the rare occurrence of rhabdomyolysis associated with hypokalemia, this pathological condition cannot be underestimated. Complaints of acute myalgia and general muscle weakness are characteristic. Early recognition of this syndrome is mandatory because myoglobinuria could provoke acute renal failure with eventual fatal outcome.