Patient-selection algorithm for outpatient shoulder arthroplasty in ambulatory surgery center: a retrospective update.

BACKGROUND: Outpatient total shoulder arthroplasty (TSA) presents a safe alternative to inpatient arthroplasty, while helping meet the rapidly rising volume of shoulder arthroplasty needs and minimizing health care costs. Identifying the correct patient for outpatient surgery is critical to maintaining the safety standards with TSA. This study sought to update an ambulatory surgery center (ASC) TSA patient-selection algorithm previously published by our institution. METHODS: A retrospective chart review of TSAs was performed in an ASC at a single institution to collect patient demographics, perioperative risk factors, and postoperative outcomes with regard to reoperations, hospital admissions, and complications. The existing ASC algorithm for outpatient TSA was altered based on collected perioperative information, review of pertinent literature, and anesthesiology recommendations. RESULTS: A total of 319 TSAs were performed in an ASC in 298 patients over 7 years. Medically related complications occurred in 3 patients (0.9%) within 90 days of surgery, 2 of whom required hospital admission (0.6%) for acute kidney injury and pulmonary embolus. There were no instances of major cardiac events. Orthopedic-related complications occurred in 11 patients (3.4%), with hematoma development requiring evacuation and instability requiring revision being the most common causes. CONCLUSIONS: There was a low rate of perioperative complications and hospital admissions, confirming the safety of TSAs in an ASC setting. Based on prior literature and the population included, a pre-existing patient-selection algorithm was updated to better reflect increased comfort, knowledge, and data regarding safe patient selection for TSA in an ASC.

Hyperammonemic Encephalopathy due to Valproic Acid and Topiramate Interaction.

Valproic acid-induced hyperammonemic encephalopathy is a rare yet serious adverse drug reaction. Medication interactions such a valproic acid and topiramate can precipitate an event. We present the case of a 52-year-old female that presented with acute mental status change and hypersomnolence due to hyperammonemia caused by a valproic acid derivative. The patient improved after withdrawal of the offending medications and treatment with lactulose. Clinicians should remain hypervigilant in monitoring for valproic acid-induced hyperammonemic encephalopathy and risk factors such as polypharmacy.

Urine Discoloration Associated With Metronidazole: A Rare Occurrence.

Objective: To report a case of metronidazole-induced urine discoloration in a patient with Clostridium difficile sepsis. Case Summary: A 52-year old man was admitted with sepsis secondary to C difficile colitis, which developed after he had been recently treated with broad-spectrum antibiotics for community-acquired pneumonia. The C difficile infection was treated with metronidazole, and the patient subsequently developed cola-colored urine. When metronidazole was inadvertently stopped for 34 hours, the urine color returned to normal, but again darkened when the medication was restarted. The patient suffered no clinically adverse effects from the abnormal urine color. He completed the treatment course for colitis and was discharged to home. Discussion: Urine discoloration is a known side of metronidazole. However, it has been poorly reported in the literature, and many clinicians are unaware that it may happen. Here we report the case of a patient who developed dark urine while receiving treatment with metronidazole. Other potential causes of the urine discoloration were explored, including hemolysis, rhabdomyolysis, or adverse reactions to other medications, with no clear positive findings. An objective causality assessment (Naranjo probability scale) revealed that the urine discoloration was probably due to metronidazole. Conclusions: Metronidazole can cause urine discoloration without otherwise harming the patient. Clinicians should be aware of this potential side effect and provide reassurance to patients who develop abnormal urine that there are no clinically relevant adverse outcomes.