Articles: cations.
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This study was conducted to document the extent to which flow depends on valve position in relation to head-pressure reference. Medtronic PS Medical Delta valves (contour model, performance levels 0.5, 1.0, 1.5, and 2.0) were studied in a bench test designed to evaluate flow rates with respect to valve position in relation to the head-pressure reference postion. The valves were connected to an "infinite" reservoir by the standard inlet catheter. ⋯ Movement of the valve above this level results in a net decrease in effective head pressure, and movement below this position results in a net increase in effective head pressure. Thus, the positioning of shunt valves in locations different from this pressure reference position should be performed only with the knowledge that significant increases in outflow rate may occur when the valve body is positioned lower than the inlet catheter tip. This increase in outflow rate is not the result of siphoning or a defect in the antisiphon device but instead the result of a net increase in effective head pressure.
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Chronic neck pain, headache, and arm pain are some of the most common patient complaints confronting today's health care provider. Chronic neck pain is reported to be a frequency symptom in 34% of the general population with 14% of the general population reporting neck pain that lasted for more than 6 months. The magnitude of the problem is demonstrated by increase of cervical spine surgery by 45% and cervical fusion by 70% over a ten year period from 1979 through 1988. ⋯ Neural blockade in the cervical spine, though introduced in 1912, lagged behind that of the lumbar spine. At the present time, neural blockade is an extremely popular tool for diagnostic purposes in evaluation of neck pain, even though it has not developed a definitive role in the management of chronic neck pain and associated syndromes. The object of this review is to focus on various aspects of neural blockade in the management of chronic neck pain and associated syndromes including its rationale, clinical effectiveness, indications, and complications.
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The use of transdermal fentanyl is gaining in importance in the management of cancer pain. We describe the reasons for switching opioid medication to transdermal fentanyl in a pain management unit. ⋯ Conversion to transdermal therapy may readjust the balance between opioid analgesia and side effects. The opioid switch resulted in more pain relief or fewer side effects in half of the patients. A proposed equianalgesic conversion ratio between 70:1 and 100:1 from oral slow-release morphine to transdermal fentanyl can be confirmed by our data. Conversion rates from other opioids to transdermal fentanyl are suggested.
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Intraventricular hemorrhage (IVH) in adults usually occurs in the setting of aneurysmal subarachnoid hemorrhage or hypertension-related intracerebral hemorrhage. Thus, the underlying cause of IVH is apparent from history and radiographic findings. If the underlying cause of IVH is not apparent, additional studies, including cerebral angiography, magnetic resonance imaging, and toxicology screening, should be performed to identify etiologic agents that may alter management of IVH. ⋯ Intraventricular injections of thrombolytic agents through an IVC is a treatment option that may be considered in all patients with IVH that is causing or threatening to cause obstructive hydrocephalus. Unrepaired cerebral aneurysms, untreated cerebral arteriovenous malformations, and clotting disorders are contraindications for this intervention. The surgical evacuation of IVH has a role only in very rare cases in which the IVH is causing a significant mass effect independent of hydrocephalus and associated intraparenchymal brain hemorrhage.
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To propose endoscopic treatment as an effective initial alternative for patients with a trapped fourth ventricle. ⋯ Endoscopic treatment of the trapped fourth ventricle is effective in most cases. In view of the higher-than-expected revision rate with fourth ventricular shunts and an equivalent complication rate, endoscopic treatment is a reasonable initial treatment option for patients with a trapped fourth ventricle.