Positive end-expiratory pressure prevents atelectasis during general anaesthesia even in the presence of a high inspired oxygen concentration

BACKGROUND: General anaesthesia impairs the gas exchange in the lungs, and moderate desaturation (SaO2 86-90%) occurred in 50% of anaesthetised patients in a blinded pulse oximetry study. A high FiO2 might reduce the risk of hypoxaemia, but can also promote atelectasis. We hypothesised that a moderate positive end-expiratory pressure (PEEP) level of 10 cmH2O can prevent atelectasis during ventilation with an FiO2 = 1.0. METHODS: Atelectasis was evaluated by computed tomography (CT) in 13 ASA I-II patients undergoing elective surgery. CT scans were obtained before and 15 min after induction of anaesthesia. Then, recruitment of collapsed lung tissue was performed as a "vital capacity manoeuvre" (VCM, inspiration with Paw = 40 cmH2O for 15 s), and a CT scan was obtained at the end of the VCM. Thereafter, PEEP = 0 cmH2O was applied in group 1, and PEEP = 10 cmH2O in group 2. Additional CT scans were obtained after the VCM. Oxygenation was measured before and after the VCM. RESULTS: Atelectasis (> 1 cm2) was present in 12 of the 13 patients after induction of anaesthesia. At 5 and 10 min after the VCM, atelectasis was significantly smaller in group 2 than group 1 (P < 0.005). A significant inverse correlation was found between PaO2 and atelectasis. CONCLUSIONS: PEEP = 10 cmH2O reduced atelectasis formation after a VCM, when FiO2 = 1.0 was used. Thus, a VCM followed by PEEP = 10 cmH2O should be considered when patients are ventilated with a high FiO2 and gas exchange is impaired.     

Methods of cost-effectiveness analysis in the evaluation of new antipsychotics: implications for schizophrenia treatment

Because health care payers are increasingly interested in learning whether new treatments offer value for money, there has been an abundance of research into the cost-effectiveness of pharmacologic therapies in the United States. In the past few years, a number of studies comparing the cost-effectiveness of the conventional neuroleptics with that of the atypical antipsychotics have been published. Cost-effectiveness analyses show the relationship between the resources used (costs) and the health benefits achieved (effects) for a health or medical intervention compared with an alternative strategy. Ideally, the analyses can help decision makers improve the health of the population by better allocating society's limited health care resources. However, the extent to which cost-effectiveness data are actually used in decision making is unclear. The analyses are sometimes viewed with skepticism, in part because studies differ in their methodological approaches. Recently, the U.S. Panel on Cost-Effectiveness in Health and Medicine offered recommendations for standard methodological practices, which may help improve the quality of studies and the acceptability of the approach in the future. The issue is particularly important in light of new legislation governing how the Food and Drug Administration will regulate promotional claims made by drug companies regarding health economic information.     

The economic cost of Alzheimer's disease and related dementias to the California Medicaid program ("Medi-Cal") in 1995.

Although state Medicaid programs may bear a large portion of the costs of Alzheimer's disease (AD), current information on spending is not available. Using a health insurance claims database for a 10% random sample of California Medicaid ("Medi-Cal") recipients 60+ years of age, the authors estimated the excess cost of AD to Medi-Cal in 1995 as the difference in expenditures between an AD cohort (those with AD or related dementias) and an age- and sex-matched cohort without AD. Among 62,450 recipients, 2,575 (4.1%) were found to have AD or related dementias, and their average payments were approximately $7,700 higher (P<0.01) than those for the comparison group. These estimates suggest that Medi-Cal spends about $200 million on AD and related dementias annually, a burden that represents nearly 10% of state spending on elderly patients.     

Experiences with the GSB (Geschwend-Scheier-Bähler) III total endoprosthesis in the elbow joint

Studies on the results with elbow prostheses published in the seventies reported on marked problems such as high loosening rates and instabilities of the joints. However, enormous progresses in elbow replacements have been made in the meantime. Therefore, we analyzed the results of the GSB III-elbow-prostheses that were implanted in our department for 9 years. Between January 1, 1987 and April 1995 at our department 34 total elbow replacements were performed in 32 patients. In this study, we reviewed 25 patients with elbow replacements both clinically and radiologically. The clinical outcome was rated according to the score of INGLIS and PELLICI. The mean follow-up time was 3.7 years. Our follow up examination revealed a total complication rate of 22%. Septic prosthesis loosening with explantation of the prostheses occurred in 3 patients resulting in a prosthesis survival-rate of 88%. However, clinical assessment revealed 80% excellent or good results. While the range of motion could only be improved to a small degree, a marked reduction of the preoperative pain could be achieved. Patients were satisfied with the outcome of the operation in 97%. Although the results of total elbow arthroplasties cannot be compared with those of hip or knee arthroplasties, in selected patients with rheumatoid arthritis and osteoathrosis the use of elbow replacements proved to be a successful procedure with satisfactory results. The implantation of elbow prostheses should mainly be considered when debilitating pain, strongly limited range of motion and instability of the joint are the main problems.     

Response of hyperhomocysteinemia to folic acid supplementation in patients with end-stage renal disease

BACKGROUND: Elevated concentrations of homocysteine are associated with an increased risk for cardiovascular disease. Reasons for elevated homocysteine concentrations are folate or vitamin B12 deficiency, renal disease or genetic abnormalities. A high prevalence of hyperhomocysteinemia is found in patients with end-stage renal disease (ESRD). Since these patients are also at increased risk for vitamin deficiency, a supplementation study comparing two doses of folic acid was performed in patients with ESRD treated with maintenance hemodialysis or with peritoneal dialysis. PATIENTS AND METHODS: Patients undergoing hemodialysis (n = 70) or peritoneal dialysis (n = 12) were supplemented with 2.5 mg or 5 mg folic acid (three times per week after each dialysis treatment) for four weeks in a parallel study design. In 20 hemodialysis patients, the effect of folic acid withdrawal was observed after four weeks. RESULTS: Both supplementation schemes reduced homocysteine to a similar extent (35%) but did not normalize homocysteine concentrations in the majority of patients. Dialysis also had a strong homocysteine lowering effect. After supplementation, 74% of the hemodialysis patients had post-dialysis homocysteine concentrations within the reference range (<16 micromol/l). Homocysteine concentrations remained decreased in 20 patients four weeks after withdrawal of folic acid supplementation. CONCLUSIONS: It is concluded that supplementation with 2.5 or 5 mg folic acid has a similar effect on homocysteine concentrations to supplementation regimens using 15 mg folic acid supplements. In contrast to the effect of folic acid supplementation in subjects with normal renal function, folic acid supplementation does not normalize homocysteine concentrations in ESRD patients.