Effects of home-based primary care on Medicare costs in high-risk elders.

OBJECTIVES: To determine the effect of home-based primary care (HBPC) on Medicare costs and mortality in frail elders. DESIGN: Case-control concurrent study using Medicare administrative data. SETTING: HBPC practice in Washington, District of Columbia. PARTICIPANTS: HBPC cases (n = 722) and controls (n = 2,161) matched for sex, age bands, race, Medicare buy-in status (whether Medicaid covers Part B premiums), long-term nursing home status, cognitive impairment, and frailty. Cases were eligible if enrolled in MedStar Washington Hospital Center's HBPC program during 2004 to 2008. Controls were selected from Washington, District of Columbia, and urban counties in Virginia, Maryland, and Pennsylvania. INTERVENTION: HBPC clinical service. MEASUREMENTS: Medicare costs, utilization events, mortality. RESULTS: Mean age was 83.7 for cases and 82.0 for controls (P < .001). A majority of both groups was female (77%) and African American (90%). During a mean 2-year follow-up, in univariate analysis, cases had lower Medicare ($44,455 vs $50,977, P = .01), hospital ($17,805 vs $22,096, P = .003), and skilled nursing facility care ($4,821 vs $6,098, P = .001) costs, and higher home health ($6,579 vs $4,169; P < .001) and hospice ($3,144 vs. $1,505; P = .005) costs. Cases had 23% fewer subspecialist visits (P = .001) and 105% more generalist visits (P < .001). In a multivariate model, cases had 17% lower Medicare costs, averaging $8,477 less per beneficiary (P = .003) over 2 years of follow-up. There was no difference between cases and controls in mortality (40% vs 36%, hazard ratio = 1.06, P = .44) or in average time to death (16.2 vs 16.8 months, P = .30). CONCLUSION: HBPC reduces Medicare costs for ill elders, with similar survival outcomes in cases and controls.

A reliable test to detect impending pump failure during long-term support on the Novacor N100 Left Ventricular Assist System.

The Durastudy is a new surveillance protocol to detect impending pump failure in Novacor N100 Left Ventricular Assist Systems implanted for the long term. Our patient, a 54-year-old man with a history of dilated cardiomyopathy and contraindications for heart transplantation, received a Novacor pump in May 1995 and did not experience sustainable ventricular recovery during the subsequent 3 years. After more than 3 years of support, symptoms of pump wear were detected in this patient, through application of the Durastudy protocol. This enabled us to electively exchange the pump at 3.8 years. Our patient remained in New York Heart Association functional class I until he died in July 1999 of causes unrelated to the pump, after some 1,514 days of support. This, we believe, still constitutes a world record.

Diagnosis and management of left ventricular assist device valve-endocarditis: LVAD valve replacement.

A 57-year-old man who has been wearing a Novacor N100 left ventricular assist device (LVAD) for more than 3 years suffered from LVAD endocarditis. Only by immunoscintigraphic methods was it possible to localize the septic focus. After successful exchange of in- and outflow tract valves, the infection was eradicated. Microscopic investigation confirmed the scintigraphic findings: Gram-positive bacteria were found. The valves showed no gross degenerative lesions after more than 1,100 days of implantation. The patient is now doing well.

The timing of do-not-resuscitate orders and hospital costs.

The relation between the timing of do-not-resuscitate (DNR) orders and the cost of medical care is not well understood. This prospective observational study compares hospital costs and length of stay of 265 terminally ill patients with admission DNR orders, delayed DNR orders (occurring after 24 hours), or no DNR orders (full code). Patients whose orders remained full code throughout a hospital stay had similar lengths of stay, total hospital costs, and daily costs as patients with admission DNR orders. Patients with delayed DNR orders, by contrast, had a greater mortality, longer length of stay, and higher total costs than full code or admission DNR patients, but similar daily costs. The causes of delay in DNR orders and the associated higher costs are a matter for future research.

[Potentiation of digoxin by itraconazole]. / Potentiëring van digoxine door itraconazol.

The case is reported of a 71-year-old woman with clinical signs of digoxin intoxication, presumably developing as a result of the simultaneous use of digoxin for cardiac abnormalities and itraconazole for infection with Candida albicans. Five similar experiences have previously been reported in the literature. Itraconazole may induce a decreased elimination of digoxin, but the mechanism of interaction is still unknown. Comedication and renal function may perhaps contribute to the degree of interaction. When itraconazole is needed in a patient also using digoxin the blood level of the latter drug should be monitored; the daily dose of digoxin may have to be decreased to only one-quarter of the original. Nausea and anorexia may be mistaken for side effects of itraconazole and be overlooked as early signs of digoxin intoxication.

Theta replication of the lactococcal plasmid pWVO2.

pWVO2 is a 3.8 kb narrow-host-range plasmid from Lactococcus lactis ssp. cremoris Wg2, which does not replicate in Bacillus subtilis or Escherichia coli. Single-stranded pWVO2 DNA was not observed in lactococcal cells, indicating that this plasmid does not replicate via a rolling-circle mechanism. The sequence of pWVO2 neither showed the structural organization typical for rolling-circle plasmids, nor were sequence similarities with known rolling-circle plasmids present. By 2-D agarose gel electrophoresis of replication intermediates, it was shown that pWVO2 replicates via a theta mechanism. This is the first proof for the existence of theta-replicating plasmids in lactococci. The pWVO2 minimal replicon is strongly related to that of several other lactococcal plasmid replicons. It contains one open reading frame encoding the replication protein, which is preceded by a 22 bp sequence tandemly repeated three and a half times. Further upstream is another 10 bp direct repeat present in an A/T-rich sequence. This structural organization resembles that of several iteron-containing theta-type plasmids from E. coli. Derivatives of pWVO2 were stably maintained in L. lactis and are good candidates for the development of stable food-grade cloning vectors for this organism.

Identification with liquid chromatography-ionspray mass spectrometry of the metabolites of the enantiomers N-methyl dextrorphan and N-methyl levorphanol after rat liver perfusion.

To gather more information on stereochemical factors in the hepatic disposition of organic cations, mass spectrometry coupled to liquid chromatography was used to determine the identity of the metabolites excreted in bile after isolated rat liver perfusions with the quaternary ammonium derivatives of the enantiomeric drugs dextrorphan and levorphanol. Ionspray mass spectrometry was chosen for its soft ionization and absence of thermal degradation of labile compounds. The drugs were labelled with a stable (2H) isotope and mixed with unlabelled drugs to create an artificial isotope pattern in the mass spectrum and facilitate the recognition of unknown metabolites. In mass spectra that were recorded under normal conditions, fragmentation was absent and metabolites of N-methyl dextrorphan and N-methyl levorphanol were visible as parent-ion 'doublets'. Collision-induced fragmentation studies were performed to support the identification of the metabolites. For N-methyl dextrorphan the glucuronide, the glutathione conjugate and the glucuronide of the N-demethylated metabolite were found in bile. For N-methyl levorphanol the glucuronide, the glutathione conjugate, the sulphate conjugate and the glucuronide of a hydroxylated N-methyl levorphanol were excreted in bile. Thus a remarkable stereoselectivity occurs in the metabolism of these quaternary ammonium compounds in the rat liver.

[Measuring model for intraoperative determination of vascular resistance in crural vascular surgery]. / Mess-Modell zur intraoperativen Bestimmung des Abflusswiderstandes in der kruralen Gefässchirurgie.

The measurement of the vascular outflow resistance during reconstructive vascular operations was applied since 1989 on 45 subjects with reliable results. This measurement is an aid for decision of additional treatment increasing the outflow, like a jump- or sequential bypass or a pharmacological therapy. The principle of measurement is based on the injection of a known volume of saline in the vessel and the integration of the intravascular pressure during this injection. In the prototype used, the pressure integration was performed by means of a modified analog/digital conversion method, hereby the results could be achieved directly as numerical values. Further an automatic, microcomputer based implementation of the outflow resistance measurement, showed remarkable improvements of accuracy in laboratory tests.

Food consumption of children with and without xerophthalmia in rural Tanzania.

Food intake of 26 children (4-9 years old) of whom nine had xerophthalmic eye lesions (Bitot's spots), was recorded over a period of four days. The principal staple foods were maize and sweet potatoes, while sorghum and cassava were also used as staple foods. The intake of energy was rather low partly due to the bulkiness of the diet. Protein intake was above the recommended intake but mainly derived from vegetable sources. The intake of retinol, beta-carotene, folic acid and iron was low in all children especially those with xerophthalmia. Dried green leafy vegetables contributed about 20% of the total beta-carotene intake during the period that the survey was carried out.

Late results following extra-anatomic bypass procedures for chronic aortoiliac occlusive disease.

During the period from 1970 to 1983 150 extra-anatomic bypass operations were carried out on 129 high risk patients revascularizing 157 extremities. There were 124 axillofemoral and 26 femorofemoral bypass grafts. In elective operations the mortality ranged from 4.9% for the axillofemoral bypass and 3.7% for the femorofemoral bypass. A five year postoperative follow-up showed a cumulative patency rate (according to life table method) of 80.21% for the femorofemoral bypass, 79.90% for the axillobifemoral bypass (Type IV) and 45.77% for the unilateral axillofemoral bypass (Type I and II). Considering the low operative mortality, the short operating time, the late results and the high late mortality independent of the surgical procedure, the femorofemoral bypass and in many ways also the axillobifemoral bypass represent suitable and effective methods of operation for high risk patients, whereas unilateral and bilateral axillofemoral grafts showed a high rate of graft thrombosis and poor long term results (Type I and III).

Microbiologic risk of invasive hemodynamic monitoring in patients undergoing open-heart operations.

The microbiologic risk of invasive hemodynamic monitoring was studied prospectively in 574 patients undergoing open-heart surgery under cover of cephalothin prophylaxis. Of a total of 2277 catheters inserted in these patients, 1.5% yielded positive cultures. The rate of positive cultures was not significantly different between percutaneous and surgically placed catheters (1.7% vs. 0.8%, respectively). Specifically, the incidence of positive catheter tips for intravenous, central venous, arterial, and pulmonary artery catheters was 1.1%, 3.9%, 1.5%, and 2.1%, respectively; while the corresponding rates for surgically inserted right atrial and left atrial catheters were 0.8% and 0, respectively. Pulmonary artery catheters had a significantly (p less than .01) higher incidence of positive catheter tips after 72 h in situ. However, there was no relationship between the in situ time and the incidence of positive tips for arterial and intravenous catheters. Although the rate of positive catheter tip cultures was low, it affected 4.9% of the patients. Nevertheless, no patient developed catheter-related septicemia or endocarditis, and the data generally supported the microbiologic safety of invasive hemodynamic monitoring in patients undergoing open-heart surgery.

[Transplant occlusion following aortofemoral bifurcation bypass: causes, therapeutic measures and results]. / Transplantatverschluss nach aorto-femoralem Bifurkationsbypass: Ursachen, therapeutische Massnahmen und Ergebnisse.

35 patients with graft thrombosis following aortobifemoral bypass grafting were analysed retrospectively (1971-1983). In 24 of these patients aortobifemoral bypass graft was performed in our own hospital and the thrombosis rate was 9.1%. 40 bypass branches and 54 graft occlusions were involved. Late occlusions were more common (75.9%), occurring after an average time interval of a little more than 5 years. Inadequate peripheral run-off with progression of the atherosclerosis was the cause in 37.5%. In 40.0% the site of occlusion was in the proximal segment of the graft, where kinking related to anastomotic technical problems played a major role. The transfemoral ring or balloon thrombectomy was successful in 45.5%. In 24.2%, however, this had to be combined with a bypass procedure (femoropopliteal or femorocrural). A change of the graft was indicated in 48.5%, but this was considered too risky in 30.3% (extraanatomic bypass: change of graft = 1.7:1). In the case of poor distal run-off a peripheral corrective procedure was a must for graft patency. In every second patient this could be achieved by profunda revascularisation. Occlusions at the central bifurcation segment are better prevented by proper anastomotic techniques. A graft with a short main trunk anastomosed to the high infrarenal aortic segment ensures a safer anastomosis and a proper position of the graft branches with little possibility of kinking. Since the routine use of this method a graft thrombosis caused by central technical problems has not been seen.