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41.
Continuous assessment of cardiac output and SVO2 in the critically ill may be helpful in both the monitoring variations in the patient's cardiovascular state and in determining the efficacy of therapy. Commercially available continuous cardiac output (CCO) monitoring systems are based on the pulsed warm thermodilution technique. In vitro validation studies have demonstrated that this method provides higher accuracy and greater resistance to thermal noise than standard bolus thermodilution techniques. Numerous clinical studies comparing bolus with continuous thermodilution techniques have shown this technique similarly accurate to track each other and to have negligible bias between them. The comparison between continuous thermal and other cardiac output methods also demonstrates good precision of the continuous thermal technique. Accuracy of continuous oximetry monitoring using reflectance oximetry via fiberoptics has been assessed both in vitro and in vivo. Most of the studies testing agreement between continuous SVO2 measurements and pulmonary arterial blood samples measured by standard oximetry have shown good correlation. Continuous SVO2 monitoring is often used in the management of critically ill patients. The most recently designed pulmonary artery catheters are now able to simultaneously measure either SVO2 and CCO or SVO2 and right ventricular ejection fraction. This ability to view simultaneous trends of SVO2 and right ventricular performance parameters will probably allow the clinician to graphically see the impact of volume loading or inotropic therapy over time, as well as the influence of multiple factors, including right ventricular dysfunction, on SVO2. However, the cost-effectiveness of new pulmonary artery catheters application remains still questionable because no established utility or therapeutic guidelines are available. 相似文献
42.
MF de Boer JF Pruyn B van den Borne PP Knegt RM Ryckman CD Verwoerd 《Canadian Metallurgical Quarterly》1995,17(6):503-515
BACKGROUND: Little is known about the rehabilitation outcomes of long-term survivors following treatment for head and neck cancer. There are, for example, no studies on physical and psychosocial rehabilitation outcomes of T1 glottic larynx carcinoma, despite the fact that these form the majority of head and neck cancer sites. Thus, this investigation afforded a unique opportunity for examining similarities and differences among T1 glottic larynx patients, laryngectomy patients, and those who had surgery for cancer of the oral cavity and/or oropharynx along a variety of physical and psychosocial dimensions. METHODS: To describe the impact of these three types of head and neck cancer and their treatment on the physical and psychosocial functioning of long-term survivors, a self-report questionnaire was completed by 110 patients treated between 2 and 6 years previously in a major cancer center. RESULTS: Data indicate that a higher percentage of patients treated with laryngectomy or commando procedures still experience severe psychosocial distress between 2 and 6 years after their last treatment than do patients treated with radiotherapy for a T1 carcinoma of the glottic larynx. Psychosocial and physical complaints are still reported by many laryngectomy patients, apparently the result of problems in effective communication with others. Many commando procedure patients experience problems with respect to food intake, and with disfigurement and its consequences. T1 larynx patients mainly experience a considerable number of physical complaints. The greater the time that had elapsed since treatment, the fewer the psychosocial problems associated with head and neck tumors. Open discussion of the illness in the family, social support, and perceptions of adequate information from the specialist are the most important predictors of positive rehabilitation outcomes. CONCLUSIONS: This study indicates that T1 larynx patients report many physical complaints even though several years had elapsed since treatment. Also, laryngectomy patients may need psychosocial guidance for a longer posttreatment period and that health care personnel must involve the partner as much as possible in all communications. Commando procedure patients in particular feel hindered by their disfigurement and its consequences. Future research with respect to validation of the specific head and neck modules is needed. 相似文献
43.
This article discusses the shift of emphasis in implantology from the phenomenon of osseointegration of implants to the accurate fabrication of the prosthesis, recognizing the implant/prosthesis unit as an actual replica rather than a replacement of the missing tooth. The study of kinetics with its succession of mandibular cycles is used to discuss the integration of mastication and occlusion. The importance of periimplant ligament in natural teeth is discussed, along with the impact of its absence on implant mobility. The impact of the bone types and the root surface architecture on the implant-bearing surface is presented along with the stress of the mastication forces. All these factors have to be considered in the treatment planning and effectively communicated to the laboratory. The learning objective of this article is to provide updated information in those areas for the reader. 相似文献
44.
45.
Nonvalvular atrial fibrillation is a frequent finding in elderly patients; the risk of thromboembolic complications is comparable to that reported in patients with rheumatic atrial fibrillation. Recently, 6 multicenter clinical trials (5 primary prevention, 1 secondary prevention trail) have been published which demonstrate equivocally that oral anticoagulation therapy significantly reduces the embolic risk in patients with nonvalvular atrial fibrillation by about 67% to 87%. The target INR of anticoagulation with warfarin in 2 of these trials was 1.4 to 2.8 (\"low-dose\" warfarin); interestingly, the magnitude of risk reduction was similar to these 2 studies with \"low-dose\" warfarin as it has been reported by the others using full-dose warfarin with an INR target between 2.0 and 4.5. Side effects of oral anticoagulation (severe bleeding complications) were low in these trials. Thus, the benefit-risk ratio in these 6 clinical trials encourage the use of oral anticoagulation in patients with nonvalvular atrial fibrillation. It will be a challenge to transfer these results to clinical practice, and to define in more detail the risk-benefit ratios for subgroups of patients with atrial fibrillation, e.g. patients > 75 years of age, or patients with \"lone\" or paroxysmal atrial fibrillation. It is well established that patients with chronic atrial fibrillation undergoing medical or DC-cardioversion are at risk for thromboembolic complications. In previous studies, this risk appears to be in the range of 2% without concomitant anticoagulation, but only 0.33% in those patients with concomitant anticoagulation. Thus, it is widely accepted that patients should be anticoagulated for at least 2 weeks prior and after planned cardioversion. Recently, an alternative concept has been proposed omitting anticoagulation before cardioversion; instead, transesophageal echocardiography is used to exclude intracardiac thrombi. Because it is known that mechanical function of the left atrium and appendage is still impaired after cardioversion, this concept of echocardiographic-guided cardioversion does not assign the necessity of anticoagulation at the day of cardioversion, and 2 weeks afterwards. The safety aspects of this concept of echocardiographic-guided cardioversion is under current investigation. 相似文献
46.
47.
This report describes a minimally invasive mitral valve repair done through a limited (6-cm) thoracic incision. The patient was supported by peripheral extracorporeal perfusion with cardiac arrest established using a new transthoracic aortic cross-clamp and antegrade blood cardioplegia. The patient was discharged on postoperative day 3 with minimal pain. This less invasive approach to mitral valve surgery may offer combined advantages to patients by increasing comfort, expediting recovery, and decreasing surgical costs by using modified traditional methods compared with specialized intraaortic occlusive balloons. 相似文献
48.
F Vincenti GM Danovitch JF Neylan RW Steiner MP Everson RS Gaston 《Canadian Metallurgical Quarterly》1996,61(4):573-577
The use of OKT3 as an immunosuppressive agent is accompanied by increased cytokine production and constellation of side effects collectively termed cytokine release syndrome (CRS). Pentoxifylline (PTF) inhibits synthesis of some cytokines, and has been shown to attenuate CRS when administered before OKT3. In this double-blinded, placebo-controlled study, 46 renal allograft recipients were randomized to receive either PTF (800 mg q 8 hr for at least 24 h) p.o. or placebo, along with methylprednisolone (7 mg/kg), diphenhydramine, and acetaminophen, prior to beginning OKT3 as therapy for acute rejection. Patients were observed, and symptoms scored semiquantitatively. Despite the presence of therapeutic PTF levels (721 +/- 726 ng/ml), the frequency and severity of side effects (fever, chills, headache, neurocortical symptoms, dyspnea, nausea, vomiting, diarrhea) did not differ between treatment groups. Likewise PTF did not affect renal function or immunologic response to OKT3, with similar graft and patient survival in both groups. Plasma levels of TNF alpha, IFN gamma, IL-6, and IL-8 increased as predicted following OKT3 administration, without significant differences between PTF and placebo groups. In this controlled, multicenter trial, pretreatment with oral PTF was ineffective in attenuating OKT3-related CRS in renal allograft recipients. 相似文献
49.
F Espa?a M Martínez J Sánchez-Cuenca CD Vera A Estellés JF Jiménez-Cruz 《Canadian Metallurgical Quarterly》1996,30(4):512-518
OBJECTIVE: To improve the specificity and sensitivity of the prostate-specific-antigen (PSA) assay for the distinction between prostate cancer and benign prostate hyperplasia (BPH). METHODS: Two sensitive immunoassays, one that measures free PSA and PSA complexed to alpha 1-antichymotrypsin (alpha 1-ACT) with the same efficiency (PSAag assay) and another that specifically measures the complex between PSA and alpha 1-ACT, have been designed to measure the PSA forms in the plasma of 84 patients with prostate disease and in the seminal plasma from 60 healthy individuals. RESULTS: The proportion of plasma PSA in complex with alpha 1-ACT was significantly higher in the 34 patients with prostate cancer (89 +/- 12%, mean +/- SD; median, 91%) than in the 50 patients with BPH (71 +/- 12%; 73%) and did not correlate with the total amount of PSA. Normal seminal plasma (n = 60) had 2.1 +/- 0.6 mg/ml PSA, 175 +/- 62 microns/ml alpha 1-ACT and 9.6 +/- 3.4 micrograms/ml PSA: alpha 1-ACT complex. CONCLUSION: These results confirm that PSA: alpha 1-ACT may be a good marker for a differential diagnosis of carcinoma of the prostate and BPH. 相似文献
50.
JF Allemand D Bensimon L Jullien A Bensimon V Croquette 《Canadian Metallurgical Quarterly》1997,73(4):2064-2070
Recent developments in the rapid sequencing, mapping, and analysis of DNA rely on the specific binding of DNA to specially treated surfaces. We show here that specific binding of DNA via its unmodified extremities can be achieved on a great variety of surfaces by a judicious choice of the pH. On hydrophobic surfaces the best binding efficiency is reached at a pH of approximately 5.5. At that pH a approximately 40-kbp DNA is 10 times more likely to bind by an extremity than by a midsegment. A model is proposed to account for the differential adsorption of the molecule extremities and midsection as a function of pH. The pH-dependent specific binding can be used to align anchored DNA molecules by a receding meniscus, a process called molecular combing. The resulting properties of the combed molecules will be discussed. 相似文献