The Journal of critical illness最新文献

Arterial cannulation is usually performed to allow continuous blood pressure monitoring or frequent arterial blood sampling. Relative contraindications to the procedure include bleeding abnormalities and peripheral vascular disease. The radial artery is the site most frequently used because the hand generally has good collateral circulation. Percutaneous cannulation is the preferred method of insertion. To avoid transecting the artery, advance the needle-catheter assembly slowly; blood return confirms arterial placement. there should be no resistance to needle advancement. Bleeding is the most common complication of arterial cannulation, but ischemia and infection have greater clinical significance.

Using indices to predict weaning outcome can avoid premature extubation and unnecessary prolongation of ventilatory support. Unfortunately, none of the indices is consistently able to predict outcome. The key to successful weaning is to assess respiratory function repeatedly with several indices, not just one. The patient should be able to sustain spontaneous breathing for at least 24 hours on minimal partial ventilatory support (a pressure support or a continuous positive airway pressure of 5 cm H2O or a T piece, for example). Indices of maximal inspiratory pressure; work of breathing; and rapid, shallow breathing are useful in evaluating a patient's respiratory muscle performance; airway occlusion pressure is helpful as well when increased neuromuscular drive is a problem.

Early, aggressive treatment is essential if patients with asystolic cardiac arrest are to survive. To maximize chances for success, use a five-phase protocol. Phase I: Confirm the diagnosis with a series of checks. Phase II: Intubate and hyperventilate the patient with 100% oxygen. Use an end-tidal carbon dioxide (ETCO2) detector to confirm tracheal intubation. Phase III: Initiate therapy with 1 mg of epinephrine and 1 mg of atropine. Consider defibrillation with a 360-wsec shock to reverse occult ventricular fibrillation. Phase IV: Repeat doses of epinephrine and atropine every 3 minutes. Phase V: Reevaluate the patient's chances of survival. If ETCO2 levels are undetectable or barely detectable (below 0.5%), survival is unlikely.

When transthoracic echocardiographic images are suboptimal, transesophageal echocardiography offers a new window for visualization of the heart and thoracic aorta. It can be performed at bedside in 15 to 20 minutes. Complications (emesis, hypoxemia, hypotension) are rare and easily reversed or averted by administration of naloxone or flumazenil. Indications include evaluation of hemodynamic instability, ventricular function, mitral regurgitation, ventricular septal defects, aneurysm, endocarditis, intracardiac sources of embolus, valve pathology, aortic dissection, intra-aortic debris, and trauma. Results can be analyzed immediately and used to guide further evaluation, medical therapy, or surgery.

Although transient bacteremia occasionally occurs after many GI endoscopic procedures, the incidence of actual infection is low. However, in addition to endocarditis, peritonitis, abscesses, meningitis, portacaval anastomotic infection, and sepsis have been reported. Prophylaxis may reduce the risk of infection; whether it is needed depends on two factors: Is the procedure to be performed associated with an increased likelihood of infection? Does the patient have an underlying condition (such as valvular heart disease or immune system incompetence) that increases the risk of such an infection? Antibiotics that are frequently used for prophylaxis include amoxicillin or gentamicin and ampicillin.

Postoperative intensive care is often required for patients who have underlying cardiac or respiratory dysfunction, who undergo major surgery, or who experience major perioperative complications. The initial report should list the patient's intravenous lines, catheters, and surgical drains or tubes, as well as whether ventilation is needed; this allows the intensive care unit (ICU) staff to set up appropriate equipment. On the patient's arrival in the ICU, document the medical history, anesthetics given, surgery performed, and intraoperative events. Perform an organ system review with ongoing assessment at 15-minute intervals. Residual effects of anesthetic agents can include respiratory depression, hypotension, and bradycardia.

The fundamental indication for cardiac transplantation is advanced heart failure that is unresponsive to medical therapy in patients with coronary artery disease or dilated cardiomyopathy. Other potential indications include advanced valvular or congenital heart disease and, more rarely, hypertrophic or restrictive cardiomyopathy, sarcoidosis, myocarditis, and primary unresectable cardiac tumors. Determining which patients have symptoms that are truly refractory to medical therapy is difficult. Ejection fraction or clinical status during acute decompensation is not a sufficient criterion for candidacy.

Decisional capacity includes ability to comprehend information, to make an informed choice, and to communicate that choice; it is specific to the decision at hand. Presume a patient has decisional capacity; an evaluation of incapacity must be justified. Administer a standardized mental status test to help assess alertness, attention, memory, and reasoning ability. A patient scoring below 10 on the Folstein Mini-Mental State Examination (maximum score, 30) probably does not have decisional capacity; one scoring from 10 to 15 probably can designate a proxy but not make complex health care decisions. Obtain psychiatric consultations for a patient who exhibits psychological barriers to decision making.

Begin by obtaining both a bleeding and a family history to help ascertain whether the disorder is acquired or inherited. On physical examination, look for multiple bleeding sites or profuse bleeding; these can indicate a systemic bleeding diathesis. Order hemostatic tests. Prolonged aPTT points to a defect in the intrinsic or common coagulation pathway; prolonged PT, to a defect in the extrinsic or common pathway. Thrombin time is abnormal when hypofibrinogenemia, afibrinogenemia, or thrombin inhibitors are present. Bleeding time is prolonged in thrombocytopenia, platelet dysfunction, severe hypofibrinogenemia, and von Willebrand's disease. Factor assays also may be needed to further define the defect.

Helicobacter (Campylobacter) pylori infection has emerged as a major cause of gastritis, peptic ulcers, and gastric malignancies. Not all patients with H. pylori infection require treatment; however, for those with ulcer disease (particularly those with bleeding), antibiotic therapy can be curative. To confirm infection (or its eradication), use the rapid urease assay, serologic examination or, when available, the urea breath test. Treatment options include triple therapy (with bismuth subsalicylate, metronidazole, and either tetracycline or amoxicillin) and dual therapy (with omeprazole and either amoxicillin or clarithromycin). For patients with an active ulcer, follow antibiotic therapy with ranitidine or omeprazole.