Cerebral salt wasting in a patient with myeloproliferative neoplasm.

BACKGROUND: Cerebral salt wasting (CSW) is a rare metabolic disorder with severe hyponatremia and volume depletion usually caused by brain injury like trauma, cerebral lesion, tumor or a cerebral hematoma. The renal function is normal with excretion of very high amounts of sodium in the urine. Diagnosis is made by excluding other reasons for hyponatremia, mainly the syndrome of inappropriate antidiuretic hormone secretion (SIADH). CASE PRESENTATION: A 60-year-old patient was admitted to the emergency room with pain in the upper abdomen and visual disturbance two weeks after knee replacement. The patient was confused with severe hematoma at the site of the knee endoprosthesis. Laboratory values showed massive thrombocytosis, leukocytosis, anemia, severe hyponatremia and no evidence of infection. CT scan of the abdomen was inconspicuous. Head MRI showed no ischemia or bleeding, but a mild microangiopathy. A myeloproliferative neoplasm (MPN) was suspected and confirmed by bone marrow biopsy. Cerebral salt wasting syndrome was identified as the cause of severe hyponatremia most likely provoked by cerebral microcirculatory disturbance. The hematoma at the operation site was interpreted as a result of a secondary von Willebrand syndrome (vWS) due to the myeloproliferative neoplasm with massive thrombocytosis. After starting cytoreductive therapy with hydroxycarbamide, thrombocytosis and blood sodium slowly improved along with normalization of his mental condition. CONCLUSION: To the best of our knowledge this is the first description of a patient with CSW most likely caused by a microcirculatory disturbance due to a massive thrombocytosis in the context of a myeloproliferative neoplasm.

Obesity and smoking predict the results of two-stage exchange in septic revision hip arthroplasty: A cohort study.

BACKGROUND: Prosthetic joint infection (PJI) is deemed to be the most serious complication following total hip arthroplasty. Obesity and smoking are known risk factors for PJI. However, the influence of these variables on infection free survival, of septic revision hip arthroplasty, is yet to be explored. The aim of this study was to determine the effect of obesity and smoking on the outcome of two-stage prosthetic exchange surgery. PATIENTS AND METHODS: A consecutive series of 97 hips in 94 patients (69 male, 25 female, mean age 66±12 years), undergoing two-stage revision surgery for hip PJI, were investigated retrospectively, after a mean follow-up of 60 (24-170) months. Survival was estimated using Kaplan-Meyer curves. A multivariate cox-regression model was applied to test for the influence of smoking or obesity (BMI≥30) after adjusting 16 potential patient-dependant variables. HYPOTHESIS: The study hypothesis was that smoking and high BMI are predictors for the failure of septic revision hip arthroplasty. Failure of septic revision hip arthroplasty was defined as failure to eradicate the infection or eradication of the infection but failure to preserve the arthroplasty. RESULTS: Kaplan-Meier showed a cumulative survival proportion of 80.4%(standard error S.E 4%), of the definitive implant, at 5 years. Obese patients (BMI≥30) and smokers had a significantly lower 5-year survival of 60.9% (S.E 1%) and 50.6% (S.E 1.4%), respectively (p=0.001). DISCUSSION: Obesity and smoking are both factors determining infection free survival in two-stage revision hip arthroplasty. Clinicians should be aware of potential complications and anticipate a higher likelihood of conversion to a Girdlestone resection or even amputation in this group of patients. LEVEL OF EVIDENCE: III, retrospective cohort study.