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At least 19 recordsLinked to original sources

[Possibilities of treatment of reversed occlusions by removable devices. Indications for treatment with removable devices according to teleroentgenograms].

The author used as a basis Jarabak's classification class III. She assessed the skeletal parameters which are important for elaboration of the therapeutic plan, for assessment of therapeutic possibilities by means of a removable device or the necessity of treatment by means of a fixed device. During analysis of the teleroentgenogram she considers it most important for the treatment by means of removable devices to assess in addition to the extent of the defect the following parameters: 1. the angle of the sella 2. the length of the body of the lower jaw 3. the inclination of the upper incisors 4. the inclination of the lower incisors

Humans↗

Rapid isolation of bacteria from septicemic patients by use of an antimicrobial agent removal device.

The new Antimicrobial Removal Device increased the efficacy of conventional methods for isolating bacteria from the blood of septicemic patients. The device removes as much as 100 microgram of antibiotics per ml from whole blood without a significant decrease in bacteria. Of 51 patients studied, 31 yielded positive cultures, and the Antimicrobial Removal Device permitted earlier isolation of the causative agent from blood. Subcultured within the first 12 h yielded 12 positive isolates, as the 31 agents were isolated more rapidly after Antimicrobial Removal Device permitted earlier isolation of the causative agent from blood. Subcultures within the first 12 h yielded 12 positive isolates, as compared to 2 when subcultured without processing in the device. Overall, 21 of the 31 agents were isolated more rapidly after Antimicrobial Removal Device treatment, and four samples were positive only after such treatment. One agent was not isolated in the treated culture.

Anti-Bacterial Agents↗

The frequency and cost of patient-initiated device removal in the ICU.

OBJECTIVE: To determine the frequency and pattern with which patients in the intensive care unit (ICU) remove medical devices on their own, and the costs associated with this problem. DESIGN: Prospective observational study. SETTING: Two 10-bed sections of a multidisciplinary ICU in a tertiary care teaching hospital. PATIENTS: Adults admitted to the ICU for longer than 24 hours during October 1998. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Medical records were reviewed prospectively for the occurrence of patient-initiated device removal and the responses to those events by health care providers. Associated costs were estimated using hospital databases and Medicare physician reimbursement schedules. Annual cost estimates were calculated using 1997 admission statistics for 1211 adults in an ICU for more than 24 hours. Thirty-six patients were studied for 199 patient-days. Ten patients (28%) removed 42 devices: 88% of these events involved gastrointestinal tubes and vascular catheters. Significant agitation was documented within 2 hours before 74% of the events. Estimated cost associated with device removal was $7606, or $181/event. The estimated annual cost in this 42-bed ICU was more than $250,000. CONCLUSIONS: Patients commonly remove medical devices on their own, and this represents significant consumption of health care resources.

Aged↗

In vitro antibiotic removal and bacterial recovery from blood with an antibiotic removal device.

The antibiotic removal device manufactured by Marion Laboratories (Kansas City., Mo.) is intended for treatment, before culture, of blood specimens from hospital patients being treated with antibiotics. Measurement of 13 antibiotics showed that the antibiotic removal device removed amikacin, ampicillin, carbenicillin, cefazolin, cephalothin, chloramphenicol, gentamicin, nafcillin, tetracycline, tobramycin, and vancomycin and reduced cefoxitin and ticarcillin to extremely low levels. Three combinations of antibiotics were similarly removed or reduced. Five species of anaerobic bacteria, one yeast species, and six species of facultative or aerobic bacteria were used to challenge the possibility that the antibiotic removal device would trap or inhibit microorganisms. All were recovered from the device in the same numbers as were inoculated.

Anti-Bacterial Agents↗

Significant reduction in circuit pressure with modified plasma separation chamber for a heparin removal device.

The heparin removal device (HRD), using plasma separation and poly-L-lysine (PLL) affinity adsorption, has been shown to be an effective alternative to protamine after cardiopulmonary bypass (CPB). Previous designs of the HRD used standard Luer-Lok ((phi = 2.3 mm) port connections between the extracorporeal tubing and the plasma separation chambers, which resulted in excessively high circuit pressures (> 750 mm Hg) at an HRD flow of 1,400 ml/min. To reduce circuit pressures, we enlarged the connection ports to phi = 4.2 mm, keeping other circuit components and sorbent amounts unchanged. The modified circuit HRD was divided into the SMALL PORT group (phi = 2.3 mm, A = 4.15 mm2) and the LARGE PORT group (phi = 4.2 mm, A = 13.85 mm2) in adult swine (70+/-5 kg) given 300 U/kg heparin. A dual lumen cannula was inserted into the right atrium and connected to the HRD. Inlet pressure ranged from 749+/-42 to 795+/-57 mm Hg in the SMALL PORT group during the HRD run at 1,400 ml/min, whereas it ranged from 345+/-5 to 372+/-34 mm Hg in the LARGE PORT group (p < 0.01 between groups). Likewise, the chamber pressure ranged from 447+/-21 to 452+/-27 mm Hg in the SMALL PORT group and from 190+/-14 to 204+/-19 mm Hg in the LARGE PORT group (p < 0.01 between groups). There were no significant differences in ACT between groups. We conclude that enlarged chamber ports significantly lower circuit pressures for the HRD without changing heparin removal capability.

Adsorption↗

Reloading the heart: a new animal model of left ventricular assist device removal.

OBJECTIVES: Left ventricular assist devices are proposed as a bridge to recovery, but recurrent ventricular deterioration has limited this approach. We describe a new animal model that simulates the effects of left ventricular assist device unloading and then reloading after device removal. The model might facilitate the evaluation of interventions intended to prevent recurrent ventricular dysfunction. METHODS: The hearts and lungs of Lewis rats were removed and transplanted into the abdomen of recipient rats by anastomosing the donor's ascending aorta to the recipient's abdominal aorta. The transplanted hearts were maintained unloaded for 2 weeks in 49 animals. Eighteen transplanted hearts were removed after 2 weeks of unloading. In 17 animals the donor's right pulmonary artery was anastomosed to the recipient's abdominal aorta to reload the heart for an additional 2 weeks. In 14 animals the hearts were maintained unloaded for 4 weeks (an additional 2 weeks). The unloaded and reloaded hearts were compared with normal rat hearts (n = 18). RESULTS: In the unloaded hearts the left ventricular end-diastolic pressures remained low. The left ventricular systolic pressures were lower than the aortic pressures. The left ventricular weights (n = 8) and volumes (n = 4) remained significantly lower ( P < .01) than in the normal hearts. Two weeks after reloading, the left ventricular end-diastolic pressure (n = 8) increased ( P < .01), and the ventricle ejected. The left ventricular systolic pressures exceeded the aortic pressures. The left ventricular weights and volumes increased ( P < .01) and approached those of normal hearts. Matrix metalloproteinase 9 (n = 6/group) levels decreased in the unloaded state ( P = .02) and increased back to normal values after reloading. CONCLUSIONS: This surgical model simulated left ventricular assist device unloading of the left ventricle. The second operation reloaded the left ventricle, which then enlarged. This model will permit the evaluation of adjunctive interventions, such as cell transplantation, intended to facilitate successful left ventricular assist device removal and prevent recurrent dilatation.

Anastomosis, Surgical↗

Non-invasive assessment of myocardial recovery on chronic left ventricular assist device: results associated with successful device removal.

BACKGROUND: Myocardial recovery may occur in patients with heart failure who are receiving left ventricular assist-device support, but identification of candidates for device removal remains challenging. We hypothesized that on-line quantitative echocardiography during trials of decreased device support alone or in combination with exercise cardiopulmonary testing can assess cardiac recovery to predict successful device removal. METHODS: We studied 18 patients with severe heart failure, aged 45 +/- 19 years, who received 234 +/- 169 days of assist-device support as a bridge to transplantation. We used echocardiographic automated border detection from mid-ventricular short-axis images and non-invasive arterial pressure to measure beat-to-beat responses in 2 to 5 minute trials of decreased device flow. We also assessed maximal oxygen consumption in 14 patients who could exercise. RESULTS: Six patients experienced myocardial recovery and underwent successful device removal; 12 remained device dependent. With transient, low assist-device flow, patients with device removal had increased echocardiographic stroke area of 27% +/- 36% vs -24% +/- 12% (p < 0.05) and fractional area change of 51% +/- 13% vs 23% +/- 11% (p < 0.05) in the patients who were device dependent. Estimates of pre-load-adjusted maximal power, a relatively load-independent index, were 6.7 +/- 2.1 mW/cm(4) in patients with successful device removal vs 1.2 +/- 1.2 mW/cm(4) in patients who were device dependent (p < 0.005). Maximal oxygen consumption was 17.2 +/- 1.4 ml/kg/min in patients with myocardial recovery vs 13.1 +/- 1.9 ml/kg/min in patients who were device dependent (p < 0.005) and correlated with pre-load-adjusted maximal power (r = 0.89, p < 0.001). Maximal oxygen consumption >16 ml/kg/min, increased stroke area, >40% increase in fractional area change, or pre-load-adjusted maximal power >4.0 mW/cm(4) with low device flow were associated with successful device removal (p < 0.05). CONCLUSIONS: On-line quantitative echocardiography alone or combined with exercise cardiopulmonary testing can assess myocardial recovery of patients receiving left ventricular assist-device support and has the potential to identify patients who are clinical candidates for device removal.

Adult↗

Heparin clearance profiles after systemic anticoagulation using a heparin removal device system.

An extracorporeal heparin removal device system (HRDS) based on plasma separation and affinity adsorption has been developed to reduce the risks of protamine-related adverse reactions. The heparin clearance profile of the HRDS was characterized by the first-order exponential depletion. A mathematical model was established to predict the time to achieve 85% heparin removal for different body weights at 700 ml/min and 1400 ml/min extracorporeal HRDS blood flow. With an HRDS flow of 700 ml, 85% of total body heparin removal cannot be achieved within 30 min for subjects greater than 50 kg. With an HRDS flow of 1400 ml/min, 85% heparin removal can be achieved within 32 min for subjects larger than 90 kg. Such model predictions were validated in an adult swine (n = 10) model of 60-min, hypothermic (28 degrees C) cardiopulmonary bypass (CPB). Animals were given 300 U/kg intravenous heparin and 5000 U heparin in the circuit prime for initial heparinization, with subsequent heparin given to maintain activated clotting time above 450 sec. Immediately following CPB, plasma heparin concentration as determined by anti-factor Xa assays was 4.40 +/- 1.08 U/ml in the 700 ml/min group and 4.78 +/- 0.70 U/ml in the 1400 ml/min groups, respectively (p > 0.05). Target HRDS flow was 700 ml/min for animals below 75 kg and 1400 ml/min for animals above 75 kg. The mean body weight in the 1400 ml/min group (81.4 +/- 3.7 kg) was significantly higher than that in the 700 ml/min group (67.2 +/- 2.2 kg) (p < 0.05), with the actually achieved HRDS flow 658.5 +/- 20.8 and 1437.4 +/- 30.1 ml/min, respectively. During the HRDS run, plasma heparin concentration followed the predicted first-order exponential depletion (r2 = 0.97 for the 700 ml/min group and r2 = 0.99 for the 1400 ml/min group). In the 700 ml/min group, the time needed to achieve 85% heparin clearance was over 40 min, whereas in the 1400 ml/min group, this time was reduced to less than 30 min despite greater body weight. At 30 min on HRDS, the 700 ml/min group had 27.4 +/- 3.7% heparin left in the plasma, whereas the 1400 ml/min group had only 12.6 +/- 2.5% (p < 0.05). The authors conclude heparin clearance by the HRDS can be precisely predicted with the mathematical model of first-order exponential depletion. Increasing the HRDS flow can effectively reduce the time needed to achieve a targeted heparin removal.

Animals↗

Evaluation of the Antibiotic Removal Device.

A new system called an Antibiotic Removal Device (ARD), used for the removal of residual antibiotics in blood specimens, was studied in 300 patients diagnosed as clinically septic despite antimicrobial therapy. Blood specimens from these patients were processed with and without the ARD into aerobic and anaerobic media. There were 53 patients who had one or more positive blood culture bottles, for a total of 109 positive blood culture bottles. Of these 109 bottles, 33.9% were positive with ARD-processed blood in aerobic media, 24.8% with ARD-processed blood in anaerobic media, 22.9% with conventionally processed blood in aerobic media, and 18.3% with conventionally processed specimens in anaerobic media. After 6 h of incubation, 14 bottles with blood processed by the ARD and 9 bottles processed conventionally were positive; after 24 h, 48 bottles with blood processed by the ARD and 31 bottles processed conventionally were positive. The same organisms were isolated from both ARD- and conventionally processed blood, with four exceptions. The ARD system, when compared with a conventional system of blood specimen processing, significantly increased the detection of bacteremia and decreased the time required for its detection in patients clinically septic despite ongoing antimicrobial therapy.

Anti-Bacterial Agents↗

The use of a heparin removal device: a valid alternative to protamine.

PURPOSE: Experiments were carried out to test the efficacy and safety of the heparin removal device, a plasmapheresis filter that binds and eliminates heparin, in the context of extracorporeal circulation. PROCEDURES AND FINDINGS: Six dogs were put on cardiopulmonary bypass after heparinization. Upon weaning, additional heparin was administered to obtain an activated clotting time above 900s. The animals were connected to the heparin removal device and with flows of 500 ml/min, activated clotting time, activated partial thromboplastin time and plasma heparin concentrations were normalised to baseline after 30 min. Hemodynamic parameters remained unaffected. A slight decrease in red and white blood cell count and in platelets was observed which however recovered spontaneously two hours after the filter procedure. No damage to blood components could be observed. CONCLUSIONS: The use of a heparin removal device is as efficient as systemic administration of protamine to reverse the effects of heparinization. It may prevent the adverse reactions linked to protamine administration and therefore be indicated in certain subgroups of patients undergoing cardiopulmonary bypass.

Animals↗

Use of the antimicrobial removal device prior to blood culture in patients on antibiotic therapy.

The efficacy of the antimicrobial removal device in facilitating isolation of bacteria from blood containing antibiotics was evaluated in a multicenter study. Blood specimens from 143 patients who had culture-proven septicemia and had been on antibiotic treatment for at least 24 hours were recultured with and without the aid of the device. Septicemia persisted in 33 of the patients and use of the device improved the isolation rates: 63% of the gram-positive bacteria and 32% of the gram-negative bacteria were isolated only with the aid of the device. Use of the device was an advantage in 10 of 13 cases where the antibiotic concentration in the bottles exceeded the MIC for the infecting microorganism but in only 5 of 19 cases where the concentration was lower than the MIC. It is concluded that the antimicrobial removal device may be useful in patients already on antibiotic treatment, but that its use is limited by the cost and the amount of work involved.

Adsorption↗

Cost effectiveness of the antibiotic removal device for processing blood cultures.

The antimicrobial removal device (ARD) blood culture system has been reported to increase the sensitivity of isolation of pathogenic microorganisms in bacteremic patients who are already on antibiotics. To determine the usefulness of this system to the clinician for the diagnosis of bacteremia and to determine the additional cost incurred by the use of the system, the microbiological results at two hospitals over a period of two years were compared. A total of 25,124 standard blood cultures (SBC) were performed with a positive culture rate of 10.7 percent. Of the 858 specimens processed by ARD alone, 68 (7.9 percent) were positive. There were a total of 2,657 specimens from 910 patients that were processed simultaneously using both systems. Both ARD and SBC were negative in 2,249 specimens, and 290 blood cultures from 107 patients grew the same organism using both systems. Thirty-one specimens from 12 patients grew pathogenic bacteria from ARD bottles; in each the SBC culture was negative. However, in 21 patients (44 specimens) bacteremia was detected only in SBC with negative cultures from ARD bottles.Thus, in the vast majority of the cases, SBC alone was sufficient to detect bacteremia, even in the patient with recent or concomitant antibiotic therapy. The total processing cost was calculated for the cases in which SBC and ARD were performed simultaneously and was found to be $6,588 for SBC and $15,005 for ARD. The comparative cost per bacteremic patient detected by the two methods was $46.40 for SBC and $555.75 for ARD.

Bacteria↗

Use of an antimicrobial removal device in endophthalmitis cultures.

PURPOSE: This study sought to determine whether the use of an antimicrobial removal device (ARD) to process intraocular fluids increases microbial detection compared with conventional cultures. METHODS: The authors retrospectively reviewed all cases of endophthalmitis submitted to their laboratory from January 1982 through December 1996. Aqueous or vitreous specimens or both that were cultured on conventional media (blood agar, chocolate agar, anaerobic blood agar, and thiol broth) and by ARD processing were included in the study. Specimens were inoculated into tubes with ARD for 5 to 10 minutes. The fluid was then withdrawn and cultured using conventional media; thioglycolate broth was added to the tube containing the resin beads. The conventional and ARD-processed cultures were incubated at 35 degrees C for at least 7 days. RESULTS: Of the 338 endophthalmitis cultures processed using both conventional cultures and a parallel ARD, 166 (49.1%) yielded positive microbial growth on one or more media. Of the 166 culture-confirmed cases, 127 (76.5%) were positive in both the ARD-processed and direct cultures, 17 (10.2%) were positive by conventional culture only, and 22 (13.3%) were positive by the ARD-processed sample alone (P = 0.52). The spectrum of microorganisms was similar among all culture groups. The detection of coagulase-negative staphylococci and micrococci by ARD alone was slightly better than detection by conventional culture only (P = 0.06). Of 93 positive cultures from 179 patients in whom prior antibiotic use was documented, 75 (80.6%) were positive by both methods, 8 (8.6%) by conventional cultures only, and 10 (10.8%) only by the ARD-processed specimen (P = 0.81). CONCLUSION: Use of an antimicrobial removal device does not significantly increase the microbial yield of endophthalmitis cultures compared with conventional culture techniques, whether or not antimicrobial therapy is being used.

Anti-Bacterial Agents↗

Evaluation of an Antimicrobial Removal Device (ARD) for detection of septicemia.

An Antimicrobial Removal Device (ARD) shown to inactivate 13 commonly used antimicrobial agents was used for processing blood samples before culture and compared with a conventional biphasic blood culture medium. 448 blood samples were processed using the ARD bottle with 472 parallel conventional cultures. The rates of clinically significant positive blood cultures were 6.9% and 8.9% respectively (not statistically significant). This study does not show any increased detection rate in ARD-processed cultures compared with conventional cultures in patients receiving antimicrobial agents.

Anti-Bacterial Agents↗

Detection of bacteremia in patients receiving antimicrobial therapy: an evaluation of the antimicrobial removal device and 16B medium.

A total of 1097 blood specimens obtained from patients receiving antibacterial antimicrobial agents were processed by three blood culture systems: standard aerobic and anaerobic radiometric media, resin-containing radiometric medium (16B; Johnston Laboratories, Cockeysville, Md.), and aerobic and anaerobic radiometric media inoculated with blood processed in an Antimicrobial Removal Device (Marion Laboratories, Kansas City, Mo.). A total of 73 cultures, representing 45 unique septic episodes, yielded 81 clinically significant organisms. Forty-six organisms (28 septic episodes) were recovered in standard radiometric medium. 16B medium yielded 63 organisms (37 septic episodes). Sixty-nine organisms (42 septic episodes) were isolated from radiometric blood cultures inoculated with Antimicrobial Removal Device-processed blood. Contamination rates were not significantly different among the three systems. In comparison with standard radiometric blood cultures, the length of time to detection of positive blood cultures was shorter with both 16B medium and with Antimicrobial Removal Device-processed cultures. Comparison of the latter two systems suggested enhanced recovery of clinically significant organisms in radiometric blood cultures inoculated with blood processed in the Antimicrobial Removal Device. There was no difference in the length of time to detection of positive blood cultures.

Anti-Bacterial Agents↗

Reversal of anticoagulation without protamine using a heparin removal device after cardiopulmonary bypass.

Protamine sulfate is routinely administered after cardiopulmonary bypass to reverse systemic heparinization, but may cause a severe hypotensive reaction in as many as 2% of patients. Research Medical, Inc., has developed an extracorporeal venovenous heparin removal device (HRD) for use in patients at high risk for a protamine reaction. Circulation through the HRD removes heparin by hollow fiber plasma separation and selective sorption of anionically charged heparin to a polycationically charged poly-L-lysine ligand coupled to a agarose substrate. The heparin depleted plasma then reenters the whole blood pathway and is returned to the patient through the double lumen catheter in the right atrium. To evaluate the HRD in a clinically relevant model, cardiopulmonary bypass was performed in pigs using RA-Ao cardiopulmonary bypass (120 min) with systemic heparinization (300 IU/kg), a nonpulsatile pump with a membrane oxygenator, and systemic hypothermia (28 degrees C). Group 1 (HEP n = 7) had no intervention to neutralize the heparin; Group 2 (HRD n = 7) used the HRD. After 19.7 +/- 4.2 min of circulation through the HRD, the activated clotting time had returned to baseline, whereas the pigs in the HEP group were still anticoagulated (activated clotting time = 396 +/- 152 sec; time to baseline was 124 +/- 9 min). There were no significant differences between groups with respect to hemodynamics, hematocrit levels, leukocyte profiles, or platelet counts, HRD is an effective heparin removal device in a pig model of cardiopulmonary bypass and awaits a phase I clinical trial in humans.

Animals↗

Mechanical circulatory support for myocarditis: how much recovery should occur before device removal?

A 12-year-old girl with presumed myocarditis was supported with right and left ventricular assist devices for 68 days before device removal. During this time, the patient underwent echocardiography and right heart catheterization for evaluation of cardiac recovery. This case report serves as the basis for a discussion of criteria for deciding when to terminate mechanical circulatory support in a patient with recovery after acute myocarditis.

Child↗

Asymmetric membrane fiber-based carbon dioxide removal devices for ion chromatography.

The application of hollow and filament-filled single asymmetric membrane fibers, consisting of a thin silicone layer on a tubular microporous support, for removing CO(2) in suppressed ion chromatography effluents is described. With appropriate choice of the removal device and operating conditions, the CO(2) can be essentially quantitatively (99+%) removed. For carbonate-based eluents, the use of such devices greatly reduces or eliminates the water dip, permitting better quantitation of poorly retained anions that elute close to the dip, allows practical gradient chromatography, and improves noise levels and attainable detection limits. In hydroxide eluent chromatography, the device largely removes the response from CO(2) present in the samples; this greatly aids atmospheric trace gas analysis by IC. Device dimensions are such that the dispersion introduced by the device is small.

Journal Article↗