Neurologic and Thrombotic Complications in the Setting of Chronic Nitrous Oxide Abuse.

Nitrous oxide is a commonly used inhaled anesthetic for medical procedures, as well as a drug of abuse throughout the world. Excessive nitrous oxide inhalation has been shown to cause a functional vitamin B12 deficiency and hyperhomocysteinemia, which can lead to peripheral neuropathy and hypercoagulability, respectively. While the development of neurologic toxicity from chronic nitrous oxide abuse (i.e., encephalopathy, myelopathy, and neuropathy) has been previously described, the thrombotic potential of chronic nitrous oxide abuse is less known. The authors report two cases of nitrous oxide abuse leading to both neurologic and thrombotic complications.

The Natural History of Gastrointestinal Bleeding in Patients without an Obvious Source.

With the advent of proton pump inhibitors and H. Pylori treatment, the old dogma "the most common cause of lower GI bleeding is upper GI bleeding" may no longer be valid. We sought to determine the most common causes of GI bleeding in patients without an obvious source and their clinical outcomes. We queried our hospital database for GI hemorrhage during 2015, excluding patients with obvious sources such as hematemesis or anal pathology. We collected data from patients with GI bleeding defined as bright red blood per rectum, melena, or a positive fecal occult blood test. The primary endpoints were etiology of GI bleed, amount of transfusions required, and types of interventions performed. Ninety-three patients were admitted with GI bleeding as defined previously: mean age was 74 years and mean hemoglobin was 8.2. Seventy-four per cent received blood transfusions with an average of 2 units transfused per patient; 22 per cent received 3 or more units of blood. The etiology of bleeding was 17 per cent upper GI source, 15 per cent lower GI source, and in 68 per cent, the source remained unknown. Bleeding stopped spontaneously in 86 per cent of patients and 9 per cent died. Endoscopy was performed in 71 per cent, but only 6 per cent underwent therapeutic endoscopic intervention. No patient had surgical or interventional radiologic procedures related to their GI bleed. Gastrointestinal bleeding, without an obvious source on presentation, rarely requires operative intervention or interventional radiologic procedure. Blood transfusions were not predictive of the need for therapeutic endoscopic intervention which was required in only 6 per cent of patients.