An 87-year-old African-American woman who was a nursing home resident with a history of diabetes mellitus type 2 came to the attention of medical staff because of continued high post-feed residuals from her tube feedings. She was aphasic and could not give a direct history to the staff. Her pertinent medical history included diabetes diagnosed nine years previously, subarachnoid hemorrhage leading to her aphasia, hemiplegia, seizures and dysphagia requiring percutaneous gastric feeds. She was completely dependent upon the tube feedings for nutritional and hydration support. She was noted to have recurrent monthly episodes of aspiration pneumonia, abdominal bloating, vomiting and large tube-feed residuals consistent with a diagnosis of underlying gastroparesis. With her ongoing decline, our patient was in a palliative state, desiring comfort measures with a limitation on testing. As a result, gastric emptying studies were not undertaken. On examination, she was aphasic with a percutaneous gastric tube in place and residuals of greater than 150mL. Her medications included allopurinol, buspirone, calcium and vitamin D, citalopram, insulin, levetiracetam, furosemide, levothyroxine, metoprolol, mexiletine, amlodipine, omeprazole, gabapentin and a prednisone taper for bullous pemphigoid. Laboratory studies showed no abnormalities and an abdominal X-ray showed no evidence of mechanical obstruction. She was started on a course of metoclopramide 30mg for pro-kinetic effect and prochlorperazine 25mg daily for nausea. Both medications provided temporary improvement in nausea and vomiting and modest reductions in her residuals.
Her nursing home course was complicated by continued episodes of recurrent aspiration pneumonia requiring hospitalization and oxygen supplementation. The doses of her anti-emetic and pro-kinetic agents were adjusted and her tube feeds were slowed significantly. There were considerable risks to our patient as the staff continued to slow the tube feeds, which placed her at risk for low nutritional intake. Despite the changes, within a couple months, her increased post-void residuals returned. Her clinical picture and family wishes precluded invasive therapies such as a gastric electric stimulator and botulinum injections. Tricyclics and erythromycin were not considered ideal with her underlying mental and neurologic disorders and medication regimen. After review of the literature for non-invasive therapies to manage recalcitrant gastroparesis, two reports of success with mirtazapine were found. One case report involved a patient with post-gastropexy-related recalcitrant gastroparesis that promptly resolved with mirtazapine . In another report, a 27-year-old woman with diabetes type 1 and gastroparesis recalcitrant to seven months of therapy with all known medication regimen and botulinum toxin injections, had resolution of her symptoms within one week of therapy with 15mg of mirtazapine .
Our patient’s residual volume decreased from greater than 170mL to less than 70mL and she had no aspiration pneumonia for months prior to her death. Efficacy was noted at a threshold dose of 15mg nightly.