Skeletal fluorosis secondary to methoxyflurane use for chronic pain.

Skeletal fluorosis is rare and occurs secondary to chronic high amounts of fluoride consumption, manifesting as diffuse osteosclerosis, skeletal pain, connective tissue calcification, and increased fracture risk. Methoxyflurane is a volatile, fluorinated hydrocarbon-inhaled analgesic, and the maximum recommended dose is 15 mL (99.9 % w/w) per wk. A rodent study found increased skeletal fluoride after methoxyflurane exposure. However, skeletal fluorosis secondary to methoxyflurane use in humans has rarely been reported. We present the case of a 47-yr-old female with diffuse osteosclerosis secondary to fluorosis from methoxyflurane use for chronic pain, presenting with 3 yr of generalized bony pain and multiple fragility fractures. Lumbar spine BMD was elevated. CT and radiographs demonstrated new-onset marked diffuse osteosclerosis, with calcification of interosseous membranes and ligaments, and a bone scan demonstrated a grossly increased uptake throughout the skeleton. Biochemistry revealed an elevated alkaline phosphatase and bone turnover markers, mild secondary hyperparathyroidism with vitamin D deficiency, and mild renal impairment. Zoledronic acid, prescribed for presumed Paget's disease, severely exacerbated bony pain. Urinary fluoride was elevated (7.3 mg/L; reference range < 3.0 mg/L) and the patient revealed using methoxyflurane 9 mL per wk for 8 yr for chronic pain. A decalcified bone biopsy revealed haphazardly arranged cement lines and osteocytes lacunae and canaliculi, which was consistent with an osteosclerotic process. Focal subtle basophilic stippling around osteocyte lacunae was suggestive of fluorosis. Although fluorosis is not a histological diagnosis, the presence of compatible histology features was supportive of the diagnosis in this case with clinical-radiological-pathological correlation. Skeletal fluorosis should be considered as a cause of acquired diffuse osteosclerosis. Methoxyflurane should not be recommended for chronic pain. The risk of repeated low-dose exposure to fluoride from methoxyflurane use as analgesia may be greater than expected, and the maximum recommended dose for methoxyflurane may require re-evaluation to minimize skeletal complications. Abbreviated abstract: Skeletal fluorosis is rare and occurs secondary to chronic high amounts of fluoride consumption, manifesting as diffuse osteosclerosis, skeletal pain, connective tissue calcification, and increased fracture risk. We present the case of a 47-yr-old female with skeletal fluorosis secondary to long-term methoxyflurane for chronic pain. The risk of repeated low-dose exposure to fluoride from methoxyflurane use for analgesia may be greater than expected, and the maximum recommended dose for methoxyflurane may require re-evaluation to minimize skeletal complications.

Searching for low phospholipid associated cholelithiasis among patients with post-cholecystectomy biliary pain.

INTRODUCTION: Low phospholipid associated cholelithiasis (LPAC) is associated with variants of the adenosine triphosphate-binding cassette subfamily B, member 4 (ABCB4) gene and is characterized by reduced phosphatidylcholine secretion into bile, impairing the formation of micelles and thus exposing bile ducts to toxic bile acids and increasing cholesterol saturation. LPAC is present in 1% of patients with gallstones and post-cholecystectomy pain is common in this group. LPAC is an under-appreciated cause of post-cholecystectomy pain. The aim of this study is to assess a cohort of patients with post-cholecystectomy pain to identify those with clinical features suggesting that further investigations for LPAC would be beneficial. METHODS: A retrospective chart review was performed of the first 2 years of post-operative follow-up for all patients under 40 years of age undergoing cholecystectomy for symptomatic gallstones at a tertiary centre between January 2016 and December 2017. RESULTS: 258 patients under the age of 40 underwent a cholecystectomy. 50 patients (19.4%) reported abdominal pain post-cholecystectomy. Five patients (1.9%) fulfilled the criteria for suspected LPAC. Family history of gallstones was documented in 33 of 258 (12.8%) of cases. Obstetric history was obtained in 69 of 197 (35%) female patients. None of the five patients identified above who satisfied the criteria of LPAC had the diagnosis of LPAC considered by their treating clinicians. CONCLUSION: LPAC is an under-recognized cause of post-cholecystectomy pain. Treatment can avoid long-term symptoms and complications. Clinicians should take a family history and obstetric history to alert them to the diagnosis of LPAC.

Pseudo-Cushing Syndrome With an Atypically High Cortisol Burden and Clinical Improvement With Adrenal Enzyme Inhibitor.

Distinguishing between Cushing syndrome (CS) and pseudo Cushing syndrome (PCS), also known as physiological hypercortisolism, can be difficult. PCS is caused by nonneoplastic overactivity of the hypothalamic-pituitary-adrenal axis and may be secondary to a range of conditions, including obesity, physical stress, malnutrition, and chronic alcoholism, and typically results in a lesser degree of hypercortisolism and fewer clinical features than CS. Management of PCS includes treatment of the underlying cause and reassessment of hypercortisolemia following improvement in the underlying etiology, as this may result in normalization of cortisol levels. The role of adrenal enzyme inhibitors in lowering cortisol levels in those with PCS is poorly understood. We report a case of a man presenting with weight loss who was found to have severe hypercortisolemia and elevated adrenocorticotropin (ACTH) complicated by infection, neuropsychiatric disturbance, and hypokalemia. Despite high cortisol levels, he was phenotypically not cushingoid, and the circadian rhythm of cortisol was preserved. Extensive investigations did not demonstrate a cause of symptoms or source of ACTH. Medical management with ketoconazole improved neuropsychiatric symptoms, and weight gain with nasogastric feeds resulted in the normalization of cortisol levels and resolution of symptoms following ketoconazole cessation.

Clinical benefits of Tocilizumab in COVID-19-related cytokine release syndrome in a patient with end-stage kidney disease on haemodialysis in Australia.

COVID-19 remains a global pandemic with more than 10 million cases and half a million deaths worldwide. The disease manifestations in patients with chronic kidney disease and especially those on haemodialysis are still being understood, with only a few overseas case series, and small observational trials thus far. It appears that the disease is more severe in this patient cohort. Part of the pathophysiology of severe COVID-19 is related to accompanying cytokine release syndrome (CRS). Tocilizumab, an interleukin-6 inhibitor, has been trialled for treatment of CRS in COVID-19, but not yet approved. We present a case of an Australian patient on long-term haemodialysis with severe COVID-19 who was successfully treated with Tocilizumab. The peak of her illness was on day 7, with a C-reactive protein of 624 mg/L (reference < 5 mg/L), ferritin of 5293 ng/mL (reference 30-500 ng/mL), and interleukin-6 level 1959.7 pg/mL, consistent with CRS. She was severely hypoxic on a ventilator, with rising inotropic requirements. With the use of Tocilizumab, there was a significant and immediate response in her inflammatory markers, and she made a steady recovery. The patient was discharged home 6 weeks after presentation.