When Two Syndromes Collide: Managing Fanconi and Refeeding Syndrome in a Single Patient

Abstract

Refeeding syndrome is the potentially fatal shift in fluids and electrolytes that may occur in malnourished patients after receiving artificial refeeding. Its hallmark feature is hypophosphatemia, although other electrolytes might also be affected. Fanconi syndrome is a generalized dysfunction of the proximal tubule characterized by proximal renal tubular acidosis (RTA), phosphaturia, glycosuria, aminoaciduria, and proteinuria. The etiology of Fanconi syndrome can be either acquired or inherited, and drugs, among them tenofovir, are a common acquired cause of this disease. We present the case of a patient with AIDS and polysubstance abuse who was admitted due to pneumonia, completed treatment, was then started on antiretroviral medication (ART) that included tenofovir alafenamide (TAF) and began presenting severe episodes of hypophosphatemia along with other electrolyte imbalances, leading the workup denoted in the case, severe complications and finally to the patient's demise. Most cases of tenofovir-related Fanconi syndrome are related to tenofovir disoproxil fumarate, but very few cases have been reported with TAF. Our case highlights this rare complication of therapy with TAF and how artificial feeding can contribute to severe electrolyte abnormalities and worsen outcomes.

Keywords: fanconi; hiv aids; infectious esophagitis; proximal renal tubule; recurrent hypoglycemia; refeeding; tenofovir alafenamide (taf); upper gastro-intestinal bleed.

Figure 1. CT chest without contrast.

CT was reported as interval development of branching opacities (tree-in-bud) and pleural-based areas of consolidation in the right upper and lower lobe, suggestive of pneumonia superimposed on chronic interstitial changes (as signaled by the red arrow). Additionally, these findings were also described: interval development of thickening of the minor fissure on the right. Diffuse bronchiectasis. Emphysema. Interval improvement of pleural-based opacity at the medial basal segment of the left lower lobe compared to previous imaging. Interval improvement of pleural-based opacity in the posterior basal segment of the right lower lobe compared to previous imaging.

Figure 2. EGD showing esophageal ulcers.

Image in the left (A) was taken at the first EGD at the level of the middle esophagus, where an esophageal ulcer can be appreciated, which was biopsied. Image in the right (B) was taken during the second EGD, which was done emergently due to gastrointestinal bleeding, but at the same time, it was done after completing fluconazole therapy. The patient was still complaining of severe dysphagia and odynophagia at the time of the second EGD. EGD: esophagogastroduodenoscopy.

Figure 3. Second EGD showing a duodenal bulb ulcer.

These are images taken from the second EGD after a concern for upper GI bleeding developed. Figures (A)-(C) are images taken from the duodenal bulb. (C) shows the duodenal bulb where a duodenal ulcer with a visible vessel (Forrest IIa) was found. EGD: esophagogastroduodenoscopy.

Figure 4. Chest x-ray taken in the ICU showing bilateral pulmonary edema.

Chest x-ray was taken in the intensive care unit and read as follows: a left IJ central line catheter is placed, terminating in the projection of mid-SVC (red arrow). Hyperinflated lungs are seen. Widespread patchy alveolar interstitial ground-glass opacities in both lung fields are seen (both white arrows). Likely small bilateral pleural effusion present (black arrows). SVC: superior vena cava.