RESUMEN
Evidence about the effectiveness of the N-methyl-D-aspartate antagonist ketamine to reduce postoperative acute and long-lasting pain is inconclusive. The aim of this study was to investigate effects of adding an intraoperative, pre-incision single intravenous dose of ketamine to a routine anaesthesia regimen on postoperative analgesic requirements, side-effects and persisting pain up to three months. After obtaining Ethical Committee approval and written informed patient consent, 120 patients were included in this prospective, randomised, double-blinded, placebo-controlled study. Patients were randomised into three groups, receiving 0.15 mg/kg ketamine intravenously, 0.5 mg/kg ketamine intravenously or normal saline in groups low-dose ketamine, moderate-dose ketamine and placebo, respectively. Anaesthesia maintenance, intraoperative pain management and postoperative pain therapy were standardised. The primary study endpoint was consumption of morphine during the first 24 hours after surgery. Three months after surgery, pain scores were assessed. Data were compared by t-test and Kruskall-Wallis test with alpha = 0.05. There was no difference between the groups in the assessed variables. These findings indicate that with the anaesthesia regimen described, and in the doses used, a single intravenous dose of ketamine does not reduce postoperative analgesic requirement or postoperative pain at three months.
Asunto(s)
Analgesia/métodos , Analgésicos/administración & dosificación , Ketamina/administración & dosificación , Dolor Postoperatorio/prevención & control , Analgésicos Opioides/administración & dosificación , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Morfina/administración & dosificación , Dimensión del Dolor , Estudios Prospectivos , Resultado del TratamientoRESUMEN
Rural America Telemedicine requires very high bandwidth to provide timely transmission of large data sets. These resources may take decades to appear because of the economics of low population densities and costly installation, and the historically low rate of bandwidth improvement available from the common communication providers. Satellites provide the natural choice for communication between the rural primary care centers and the tertiary care hospital. Furthermore recent improvements in technologies have substantially reduced the costs of ground stations. A network of satellite ground stations with symmetric bandwidth connected by satellite is the architecture of choice. Analysis of multi-station satellite access clearly argues for distributed non-random methods and hence for appropriate handling of TCP data streams. However the overhead in delay of Satellite based TCP, as required for Internet access, substantially increases the transmission time and hence cost. Simulations of TCP/IP data over satellite links show a substantial reduction in transmission times. Initial business models show that the transmission cost per second is 60 times that of telephone lines while the increase in speed is nearly 3000 fold, effecting a 50 fold cost savings. But over decades, the infrastructure can be expected to improve. In particular speculative fiber optic installations in power lines and along major highways are betting on future traffic. These so-called dark fibers take advantage of synergistic installations. Their small size, ease of manipulation and gigantic bandwidths (in terabytes) allows for economic installation in anticipation of future use. Thus for rural America a strategy can evolve in which satellites provide an intermediate solution to high speed data communication while the terrestrial fiber-optic infrastructure catches up.
Asunto(s)
Servicios de Salud Rural , Comunicaciones por Satélite , Telemedicina , Redes de Comunicación de Computadores , Tecnología de Fibra Óptica , Humanos , Fibras Ópticas , Estados UnidosRESUMEN
HISTORY AND ADMISSION FINDINGS: A 57-year-old woman with metastasizing ovarian cancer and chronic renal failure was admitted for morphine treatment of an acute lumbospinal pain syndrome, ambulant treatment with analgesics having failed provide adequate pain relief. On admission due to pain the conscious patient presented with reduced general condition and lumbal pain sensitive to tapping. Lasègue's sign was positive on both sides, no other disturbed neurological functions were found. TREATMENT AND COURSE: On the 7th day of morphine administration she became somnolent and breathing became markedly depressed, indicating overdosage, metabolic and intracranial causes having been excluded. Naloxone, an opioid antagonist, was given i.v. and the breathing pattern improved. But drowsiness continued for another 48 hours and only regressed after repeated doses of naloxone. CONCLUSIONS: Morphine-6-glucuronide (M6G), formed from morphine in the liver, accumulates in blood and penetrates the blood-brain barrier, binding with strong affinity to opiate receptors and exerts a strong analgesic effect. As M6G is excreted by the kidney, its concentration rises in renal failure and can lead to severe intoxication. Morphine dosage must therefore be carefully controlled in patients with renal failure.