Medicine (Abingdon, England : UK ed.)最新文献

Gastrointestinal (GI) complications of diabetes mellitus are common and substantially decrease health-related quality of life. Diabetes can affect every part of the GI tract, from the oesophagus to the rectum, and causes various symptoms, including reflux, heartburn, nausea, vomiting, abdominal pain, diarrhoea and constipation. Diabetes-induced GI complications are collectively referred to as diabetic gastroenteropathy. Over recent years, investigation of the underlying pathogenesis of diabetes-induced GI complications has provided objective evidence of abnormalities in the enteric nervous system, essential for normal motility within the GI tract. The diagnosis of diabetic gastroenteropathy is complex, and other causes of GI symptoms should be excluded. There is currently no cure for diabetic gastroenteropathy. Hence, treatment goals are to slow progression, relieve symptoms and manage complications. The key is tight glycaemic control, dietary advice and occasionally pharmacological treatment.

Video-capsule endoscopy is a non-invasive technology that directly visualizes the mucosa of the gastrointestinal (GI) tract. Small bowel capsule endoscopy (SBCE) is a first-line test for investigating the small bowel. The most common indications for SBCE include suspected small bowel bleeding, iron deficiency anaemia, suspected Crohn disease (CD) and the assessment of established CD. SBCE is safe and well tolerated by patients. The most common complication of SBCE is capsule retention, defined as retention of the capsule in the GI tract for >2 weeks after ingestion. Most cases of capsule retention can be managed conservatively. However, endoscopic retrieval of the capsule or surgery can be required if the patient develops obstructive symptoms. Patients at higher risk of capsule retention should first undergo assessment with a patency capsule. Video-capsule endoscopy technology has also been used to examine the colon and the stomach. Colon capsule endoscopy requires a more intensive bowel preparation regime than standard colonoscopy. Its use in assessing inflammatory bowel disease, in surveillance of the colon and for patients with symptoms suggestive of colonic pathology has been investigated. A pan-enteric capsule and capsules that assess the upper GI tract have also been developed.

Endoscopic ultrasonography (EUS) is a high-frequency, high-resolution, real-time modality for imaging the gastrointestinal tract and surrounding extramural structures. Originally introduced as a diagnostic tool, EUS is primarily used to stage luminal malignancies, including tissue acquisition, and to assess pancreatic and subepithelial lesions, particularly in individuals fit for surgery. In addition, therapeutic EUS has expanded into a range of indications for the treatment of gastrointestinal diseases. This review explores its diagnostic and therapeutic uses.

Chronic pancreatitis is a fibro-inflammatory disease of the pancreas characterized by inflammation and fibrosis. It is associated with excessive alcohol consumption and smoking, although a number of other risk factors are increasingly recognized, including a genetic predisposition. Patients typically present with upper abdominal pain, weight loss and changes in bowel habits caused by exocrine pancreatic insufficiency. Additionally, chronic pancreatitis is frequently complicated by post-pancreatitis diabetes mellitus and a number of other conditions, including common bile duct stenosis and duodenal obstruction. Because of malabsorption, patients also have an increased risk of osteoporosis and low-energy fractures. Alcohol abstinence and smoking cessation are key elements of management. Pain is often the most prominent symptom and has a multifactorial aetiology that requires a multidisciplinary treatment approach, including specialized endoscopic and surgical expertise. Exocrine pancreatic insufficiency is treated by enzyme replacement therapy with careful monitoring of patients’ macro- and micronutritional state, including a systematic assessment of bone health. Post-pancreatitis diabetes mellitus requires special therapeutic considerations because of a high risk of hypoglycaemia. Most patients obtain acceptable quality of life when adhering to modern treatment recommendations.

Poisoning by venomous creatures is common. Most is benign, causing only minor irritation or pain, but rarely significant morbidity and mortality can occur. Medically important venomous creatures include snakes, spiders, scorpions and marine creatures. For suspected cases of severe envenoming, seek early expert advice from a clinical toxicologist or poisons information centre. First aid measures include pressure bandaging of the affected limb with immobilization in suspected snakebite and funnel web spider bite, and hot water immersion therapy for many marine stings. Management of severe envenoming requires resuscitation with early provision of antivenom where available. Ensure the patient has adequate tetanus prophylaxis. Pain is often prominent and adequate analgesia should be provided. Primary prevention of bites and stings is crucial to reduce the impact of envenoming.

Opioids are among the most commonly prescribed analgesic medications, and opioid toxicity is becoming an increasing problem across the world. Patients typically present with a triad of signs: reduced consciousness, miosis and a reduced respiratory rate with shallow breaths. Patients with significant opioid toxicity are at risk of airway compromise, and basic supportive measures should be performed. Naloxone is a non-selective μ-opioid receptor antagonist that competitively binds to the μ-opioid receptor and should be administered, ideally intravenously, to patients with significant opioid toxicity.

Tricyclic antidepressants, citalopram, venlafaxine and monoamine oxidase inhibitors are the most toxic antidepressants in overdose. Features include hypotension and arrhythmias that are best managed by the aggressive correction of metabolic acidosis with sodium bicarbonate. Antipsychotic drugs differ in their chemical structure and specificity at dopamine receptors. Overdose produces a range of adverse effects including sedation and acute extrapyramidal reactions. Cardiovascular effects including hypotension, prolongation of the QT interval and, potentially, arrhythmias including torsade de pointes are also seen.

Assessment of patients with acute poisoning includes history-taking, assessment of airway, breathing, circulation and consciousness level, physical examination to elicit relevant clinical signs and appropriate investigations. Diagnosis is usually based on the history, recognition of toxidromes (when present) and results of investigations.

While the misuse of traditional drugs remains common, the emergence of new psychoactive substances (NPS) has changed the landscape of drug misuse in recent years. Although hundreds of NPS have been identified, opioids, including new synthetic examples, still dominate mortality. The exact substances causing toxicity are often unknown on presentation, and multiple exposures are commonly involved. Management is therefore based on a recognition of the drug group(s) involved by identifying the clinical toxidrome. Depressants, stimulants, hallucinogens, cannabinoids and dissociatives represent the most frequently identified drug toxidromes.

Accidental carbon monoxide (CO) poisoning causes 100 hospital admissions and 7 deaths per million UK population. Toxicity occurs mainly through the formation of carboxyhaemoglobin (COHb), causing ischaemia of vital organs. Features are non-specific and include headache, gastrointestinal upset, dizziness, weakness, convulsions, coma, chest pain and dyspnoea. Neuropsychiatric features can appear up to 40 days after the initial exposure. The diagnosis can be missed unless a history of exposure to sources of CO is elicited or a CO alarm triggered. There may be a history of others (including pets) with a similar illness in a particular location (e.g. home, office) and an improvement in symptoms when away from that location. A COHb concentration >5% in non-smokers, and >10% in smokers, indicates CO poisoning. A COHb concentration >30% indicates severe poisoning, although lower concentrations do not rule out severe CO poisoning. Patients should be treated with high-flow oxygen, which usually results in rapid improvement. Complications, including myocardial infarction and stroke-like features, should be managed conventionally. The source of CO should be identified and eliminated. Patients and families should be educated to prevent CO poisoning in the community.