Kalyana C. Janga

Unpredictable Nature of Tolvaptan in Treatment of Hypervolemic Hyponatremia: Case Review on Role of Vaptans

Hyponatremia is one of the most commonly encountered electrolyte abnormalities occurring in up to 22% of hospitalized patients. Hyponatremia usually reflects excess water retention relative to sodium rather than sodium deficiency. Volume status and serum osmolality are essential to determine etiology. Treatment depends on several factors, including the cause, overall volume status of the patient, severity of hyponatremic symptoms, and duration of hyponatremia at presentation. Vasopressin antagonists like tolvaptan seem promising for the treatment of euvolemic and hypervolemic hyponatremia in heart failure. Low sodium concentrations cause cerebral edema, but the overly rapid sodium correction can also lead to iatrogenic cerebral osmotic demyelination syndrome. Demyelination may occur days after sodium correction or initial neurologic recovery from hyponatremia. The following case report analyzes the role of vasopressin antagonists in the treatment of hyponatremia and the need for daily dosing of tolvaptan and the monitoring of serum sodium levels to avoid rapid overcorrection which can result in osmotic demyelination syndrome (ODS).

GAD65 Positive Autoimmune Limbic Encephalitis: A Case Report and Review of Literature

Limbic encephalitis is a rare disorder affecting the medial temporal lobe of the brain, sometimes also involving hippocampus atrophy. It was initially considered to be only of paraneoplastic origin but now auto-immune (non-paraneoplastic) cases have also been reported. Most common non paraneoplastic antibodies associated with limbic encephalitis are Voltage gated potassium channel antibodies, NMDA receptor antibodies and GAD receptor antibodies. We present a case of limbic encephalitis which presented with sudden onset seizures which was preceded by confusion, disorientation and other psychiatric symptoms for a period of 5 weeks. No tumor was found on imaging and the classic paraneoplastic panel was negative. CSF and serum examination showed high titers GAD65 antibody guiding towards a diagnosis of non paraneoplastic limbic encephalitis. Her symptoms and GAD 65 antibody titers showed significant improvement following immunomodulatory therapy. The case presented here is unique and scientifically relevant, as it intends to raise awareness of Auto-immune Limbic Encephalitis, a potentially reversible cause of a medical emergency.

Superior vena cava and right atrium wall infective endocarditis in patients receiving hemodialysis

Infective endocarditis is significantly more common and causes greater morbidity and mortality in patients receiving hemodialysis than in the general population. Episodes of bacteremia during hemodialysis are primarily the result of frequent vascular access through an arteriovenous fistula, a vascular graft, or an indwelling vascular catheter. This leads to dialysis access infection and secondary bacteremia. We describe 4 cases of patients receiving hemodialysis, with an indwelling intravascular dialysis catheter, who developed right-sided endocarditis with vegetations located exclusively on the superior vena cava and right atrium wall. All patients had persistent bacteremia with Staphylococcus, secondary to an indwelling intravascular hemodialysis catheter, which led to seeding of the right-sided cardiac wall, causing infective endocarditis. The rates of acceptance for hemodialysis are increasing, along with improved survival in this group of patients. This will probably lead to an increase in the incidence of infective endocarditis, with atypical presentations such as superior vena cava and right-sided cardiac wall endocarditis.

Diabetic Muscle Infarction Masquerading as Necrotizing Fasciitis

A 43-year-old male patient with past medical history of diabetes mellitus (DM), end stage renal disease (ESRD) on hemodialysis (HD), congestive heart failure (CHF), obstructive sleep apnea (OSA), and chronic anemia presented with complaints of left thigh pain. A computerized tomogram (CT) of the thigh revealed evidence of edema with no evidence of a focal collection or gas formation noted. The patients clinical symptoms persisted and he underwent magnetic resonance imaging (MRI) of his thigh which was reported to show small areas of muscle necrosis with fluid collection. These findings in the acute setting concerned necrotizing fasciitis. After careful discussion following a multidisciplinary approach, a decision was made to perform a fasciotomy with tissue debridement. The patient was treated with IV antibiotics and discharged with a vacuum assisted wound drain. The surgical pathology revealed evidence of muscle edema with necrosis. Seven weeks later the patient presented with similar complaints on the other thigh (right thigh). MRI of the thighs revealed worsening edema with features suggestive of myositis and possible muscle infarction. A CT guided biopsy of the right quadriceps muscle revealed fibrotic interstitial connective tissue and no evidence of necrosis. This favored a diagnosis of diabetic muscle infarction. The disease was managed with pain control, strict diabetes management, and aggressive dialysis.

Tolvaptan in the treatment of acute hyponatremia associated with acute kidney injury.

Hyponatremia defined as a plasma sodium concentration of less than 135 mmol/L is a very common disorder, occurring in hospitalized patients. Hyponatremia often results from an increase in circulating arginine vasopressin (AVP) levels and/or increased renal sensitivity to AVP, combined with an increased intake of free water. Hyponatremia is subdivided into three groups, depending on clinical history and volume status: hypovolemic, euvolemic, and hypervolemic. Acute symptomatic hyponatremia is usually treated with hypertonic (3%) saline. Syndrome of inappropriate antidiuretic hormone hypersecretion (SIADH) and hypervolemic hyponatremia caused by heart failure or cirrhosis are treated with vasopressin antagonists (vaptans) since they increase plasma sodium (Na2+) concentration via their aquaretic effects (augmentation of free-water clearance). The role of tolvaptan in the treatment of acute hyponatremia and conversion of oliguric to nonoliguric phase of acute tubular necrosis has not been previously described.

Nontraumatic Exertional Rhabdomyolysis Leading to Acute Kidney Injury in a Sickle Trait Positive Individual on Renal Biopsy

A 26-year-old African American male with a history of congenital cerebral palsy, sickle cell trait, and intellectual disability presented with abdominal pain that started four hours prior to the hospital visit. The patient denied fever, chills, diarrhea, or any localized trauma. The patient was at a party at his community center last evening and danced for 2 hours, physically exerting himself more than usual. Labs revealed blood urea nitrogen (BUN) level of 41 mg/dL and creatinine (Cr) of 2.8 mg/dL which later increased to 4.2 mg/dL while still in the emergency room. Urinalysis revealed hematuria with RBC > 50 on high power field. Imaging of the abdomen revealed no acute findings for abdominal pain. With fractional excretion of sodium (FeNa) > 3%, findings suggested nonoliguric acute tubular necrosis. Over the next couple of days, symptoms of dyspepsia resolved; however, BUN/Cr continued to rise to a maximum of 122/14 mg/dL. With these findings, along with stable electrolytes, urine output matching the intake, and prior use of proton pump inhibitors, medical decision was altered for the possibility of acute interstitial nephritis. Steroids were subsequently started and biopsy was taken. Biopsy revealed heavy deposits of myoglobin. Creatinine phosphokinase (CPK) levels drawn ten days later after the admission were found to be elevated at 334 U/dl, presuming the levels would have been much higher during admission. This favored a diagnosis of acute kidney injury (AKI) secondary to exertional rhabdomyolysis. We here describe a case of nontraumatic exertional rhabdomyolysis in a sickle cell trait (SCT) individual that was missed due to findings of microscopic hematuria masking underlying myoglobinuria and fractional excretion of sodium > 3%. As opposed to other causes of ATN, rhabdomyolysis often causes FeNa < 1%. The elevated fractional excretion of sodium in this patient was possibly due to the underlying inability of SCT positive individuals to reabsorb sodium/water and concentrate their urine. Additionally, because of their inability to concentrate urine, SCT positive individuals are prone to intravascular depletion leading to renal failure as seen in this patient. Disease was managed with continuing hydration and tapering steroids. Kidney function improved and the patient was discharged with a creatinine of 3 mg/dL. A month later, renal indices were completely normal with persistence of microscopic hematuria from SCT.

Nephrologists Hate the Dialysis Catheters: A Systemic Review of Dialysis Catheter Associated Infective Endocarditis

A 53-year-old Egyptian female with end stage renal disease, one month after start of hemodialysis via an internal jugular catheter, presented with fever and shortness of breath. She developed desquamating vesiculobullous lesions, widespread on her body. She was in profound septic shock and broad spectrum antibiotics were started with appropriate fluid replenishment. An echocardiogram revealed bulky leaflets of the mitral valve with a highly mobile vegetation about 2.3 cm long attached to the anterior leaflet. CT scan of the chest, abdomen, and pelvis showed bilateral pleural effusions in the chest, with triangular opacities in the lungs suggestive of infarcts. There was splenomegaly with triangular hypodensities consistent with splenic infarcts. Blood cultures repeatedly grew Candida albicans. Despite parenteral antifungal therapy, the patient deteriorated over the course of 5 days. She died due to a subsequent cardiac arrest. Systemic review of literature revealed that the rate of infection varies amongst the various types of accesses, and it is well documented that AV fistulas have a much less rate of infection in comparison to temporary catheters. All dialysis units should strive to make a multidisciplinary effort to have a referral process early on, for access creation, and to avoid catheters associated morbidity.

A Rare Case of Central Pontine Myelinolysis in Overcorrection of Hyponatremia with Total Parenteral Nutrition in Pregnancy.

A 42-year-old high risk pregnant female presented with hyponatremia from multiple causes and was treated with total parenteral nutrition. She developed acute hypernatremia due to the stage of pregnancy and other comorbidities. All the mechanisms of hyponatremia and hypernatremia were summarized here in our case report. This case has picture (graph) representation of parameters that led to changes in serum sodium and radiological findings of central pontine myelinolysis on MRI. In conclusion we present a complicated case serum sodium changes during pregnancy and pathophysiological effects on serum sodium changes during pregnancy.

Elevated Amylase in Clostridium difficile–Associated Diarrhea: A Case Report and Follow-Up Retrospective Study

BackgroundClostridium difficile–associated diarrhea (CDAD) is associated with high morbidity and mortality. There are several risk factors that have been identified that are linked to worsening outcomes including age of the patient, length of hospitalization, comorbidities, use of certain high-risk antibiotics, and more recently renal insufficiency. At our institution, we recently identified a patient with recurrent CDAD with elevated amylase level. More impressively, his level of amylase followed the course of his infection and returned to normal during his remission state. We proposed an association between C. difficile infection and amylase level. MethodsWe enrolled 726 patients who were 18 years or older, who had a history of CDAD and positive C. difficile toxin at time of diagnosis and had a measurement of amylase level within 3 days of toxin positivity. Patients were excluded if amylase levels were measured 3 days before or 3 days after C. difficile toxin positivity or were younger than 18 years. This study was retrospective in design. We also gathered other laboratory data such as basic metabolic panel, complete blood count, liver function test, lipase, length of hospital stay, and patient outcome of those who met the inclusion criteria. The primary outcome was death during hospitalization, and secondary outcome was length of stay. We also did a subset analysis looking at variables such as age, sex, albumin, renal insufficiency, anemia, amylase level, and leukocytosis and its association with C. difficile. ResultsA total of 726 cases of CDAD were identified. Overall hospital mortality was 26.6%, and mean length of stay was 25.3 days. When analyzing with logistic regression, only increasing age (odds ratio, 1.08; P < 0.001), increased creatinine (odds ratio, 1.50; P = 0.003), and decreased albumin (odds ratio, 0.19; P = 0.001) were associated with increased in-hospital mortality. All other factors including sex, white blood count, hemoglobin, and amylase did not show any change in mortality. ConclusionsBased on this retrospective study, we were unable to identify any relationship between amylase level and CDAD. Secondary outcomes from the analysis revealed that whereas increasing age, decreased albumin, and renal insufficiency put one at risk for C. difficile infection, other factors such as sex, anemia, leukocytosis, and amylase level cannot be used to risk stratify patients.