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At least 127 records · Page 7Linked to original sources
PubMed2001

Fungal left ventricular assist device endocarditis.

BACKGROUND: Infection remains as the most serious complication and represents a significant threat to patients during long-term mechanical circulatory support. Fungal infection is a particularly worrisome complication and left ventricular assist device (LVAD) endocarditis does pose a serious threat. METHODS: One hundred and sixty-five patients underwent TCI Heartmate LVAD implantation between July 1991 and December 1999 at our institution. Detailed medical records were kept prospectively for all patients, and a variety of infection-related endpoints were analyzed on patients with fungal LVAD endocarditis. RESULTS: Thirty-seven patients (22%) developed fungal infections during LVAD support. Five (3%) of those met our criteria for the diagnosis of fungal LVAD endocarditis. Microbial portals of entry were identifiable in all cases. Infections were managed successfully in 4 patients (80%). CONCLUSIONS: The successful management of fungal LVAD endocarditis currently requires early recognition of potentially nonspecific signs and symptoms, and timely institution of antifungal therapy. In some cases with device-specific manifestations of LVAD endocarditis, device removal and replacement is necessary. In patients with clinical manifestations of sepsis and fungal driveline site or pocket infections without positive blood culture, urgent transplantation may be the appropriate management. In the setting of shortage in the donor supply, device removal and replacement is necessary.

Amphotericin B↗
PubMed2003

The Günther Tulip retrievable filter: prolonged temporary filtration by repositioning within the inferior vena cava.

PURPOSE: To report experience with the retrievable Günther Tulip filter (GTF) as a means of temporary caval filtration for the prevention of pulmonary embolism (PE) with use of a technique that prolongs filter dwell time beyond 14 days. MATERIALS AND METHODS: Eighty-eight GTFs were implanted in 87 patients. The GTFs were placed with the intention of retrieval in all patients within 14 days after initial implantation. In 23 of the 87 patients (26%), there was a need to prolong temporary caval filtration beyond the recommended period of 14 days. This was successfully achieved with use of percutaneous techniques from the right internal jugular vein whereby the filter was repositioned to a different location within the inferior vena cava (IVC) before definitive device removal. RESULTS: Of 88 GTFs implanted in 87 patients, 70 were successfully retrieved and 18 were left in place permanently. Forty-seven filters in 46 patients were removed after initial implantation with no need for percutaneous repositioning within the IVC to prolong dwell time (mean dwell time, 13 days). In the 23 patients who required repositioning of 23 GTFs within the IVC to prolong temporary caval filtration, the mean dwell time was 34.8 days; the mean number of repositioning procedures was 1.5, the mean time between repositioning procedures was 13.8 days, and the mean fluoroscopy time was 4.4 minutes in patients in whom filter retrieval was attempted. One patient underwent placement and subsequent removal of the GTF twice for perioperative prophylaxis against PE on two separate occasions. No filters were misplaced in an unintended location or tilted (>15 degrees ) in relation to the main caval axis after deployment. In one patient, a GTF became permanently fixed in the IVC 16 days after initial implantation and could not be removed percutaneously. Nine patients had mild or moderate-sized cervical hematomas. One patient had recurrent asymptomatic PE 2 months after filter insertion. CONCLUSION: Dwell times of 14 days can be achieved in most patients before device removal. Prolongation of the dwell time beyond 14 days can be safely and easily achieved by performing percutaneous repositioning of the device within the IVC via a jugular approach.

Adolescent↗
PubMed2003

Nucleic acid purification using microfabricated silicon structures.

A microfluidic device has been designed, fabricated and tested for its ability to purify bacteriophage lambda DNA and bacterial chromosomal DNA, a necessary prerequisite for its incorporation into a biosensor. This device consists of a microfabricated channel in which silica-coated pillars were etched to increase the surface area within the channel by 300-600%, when the etch depth is varied from 20 to 50 microm. DNA was selectively bound to these pillars in the presence of the chaotropic salt guanidinium isothiocyanate, followed by washing with ethanol and elution with low-ionic strength buffer. Positive pressure was used to move solutions through the device, removing the need for centrifugation steps. The binding capacity for DNA in the device was approximately 82 ng/cm2 and on average, 10% of the bound DNA could be purified and recovered in the first 50 microl of elution buffer. Additionally, the device removed approximately 87% of the protein from a cell lysate. Nucleic acids recovered from the device were efficiently amplified by the polymerase chain reaction suggesting the utility of these components in an integrated, DNA amplification-based biosensor. The miniaturized format of this purification device, along with its excellent purification characteristics make it an ideal component for nucleic acid-based biosensors, especially those in which nucleic acid amplification is a critical step.

Adsorption↗
PubMed1990

[The condition of periodontium in children treated with removable orthodontic devices].

The purpose of the study was establishing whether, and if so, which regulatory devices traumatize the parodontal tissues. Clinical examination was done in 60 children treated with functional devices and 20 with mechanical devices before the treatment and 3 to 5 months after treatment beginning. The condition of the parodontium was assessed by means of the gingival index and the periodontal index of Russell. Oral hygiene was assessed using the plaque index. In the light of the obtained results it may be said that removable functional and mechanical devices for teeth regulation caused no pathological changes in parodontal tissues in children aged 7-10 years.

Child↗
PubMed1994

Sepsis caused by Flavimonas oryzihabitans.

Previous reports of F. oryzihabitans sepsis involving central venous access devices reveal a relatively high rate of complications, including device removal, despite a course of broad-spectrum anti-microbials with compatible in vitro susceptibility results. In the present report of 22 cases of F. oryzihabitans sepsis treated at Memorial Sloan-Kettering Cancer Center from February 1986 through September 1993, the majority of CVAD-related infections with F. oryzihabitans were successfully treated with a 14-day course of antimicrobials with antipseudomonal activity, and removal of the device was usually not required. Factors that may complicate successful treatment of CVAD-related sepsis caused by F. oryzihabitans include polymicrobial infections and premature discontinuation of antibiotic therapy.

Adult↗
PubMed1987

The design and analysis of a laminated partially degradable composite bone plate for fracture fixation.

During the early stages of fracture healing, rigid internal fixation maintains alignment and promotes primary osseous union. Unfortunately, as healing progresses rigid fixation from bone plating can cause bone in the region of the plate to undergo stress protection atrophy. This can result in significant loss of bone mass and osteoporosis. Refracture of the bone upon device removal is a widely reported complication. In an effort to minimize or eliminate stress protection atrophy, we have designed a partially absorbable, fiber-reinforced bone plate. Ideally, such a plate gradually loses rigidity as the fracture heals, increasingly transferring stress to the bone. Stress protection may be avoided and removal of the device after healing may be unnecessary. Composite theory was used to determine an optimum fiber layup for a composite bone plate. Composite analysis suggested the mechanical superiority of a 0 degree/ +/ -45 degree laminae layup. Given this laminated design, a thermoplastic absorbable polymer (polylactic acid polymer) was reinforced with high-modulus carbon fiber to produce a semiabsorbable composite. Implant evaluation included optimizing fabrication techniques, thorough mechanical device testing, and implantation on canine femurs to determine biocompatibility and efficacy. The composite design proved to have superior static and fatigue properties to laminated or random fiber designs used previously. Two techniques for hole fabrication were tested. The production of screw holes during the molding process rather than machining postmolding, improved the mechanical integrity of the finished plate. Although the 0 degree/ +/- 45 degree carbon/polylactic acid composite possessed superior mechanical properties, it was unsuccessful in the in vivo environment. Water absorption and subsequent delamination made the plate flexible. Hypertrophic nonunions developed. Further development to prevent water intrusion and premature loss of mechanical properties is necessary.

Absorption↗
PubMed1983

Late functional and hemodynamic status of surviving patients following insertion of the left heart assist device.

Since July, 1978, we have inserted a roller pump type of left heart assist device between the left atrium and ascending aorta in 35 patients. There were no significant complications related to use of the device. Seventeen patients recovered sufficiently to have the device removed. There were four early deaths, 60 to 120 days following removal of the device. Three of these patients died of septic complications and one patient died as a result of a cardiac arrest. Of the 13 long-term survivors, seven are working and six are retired. Five patients have mild to moderate cardiac symptoms, whereas eight others are completely asymptomatic. In three patients the ejection fraction was significantly lower than preoperatively; however, in all other patients the ejection fraction either stayed the same or improved postoperatively. We conclude that this type of left heart assist device can provide adequate cardiac support in patients with profound left ventricular dysfunction following cardiac operations. Furthermore, surviving patients generally have satisfactory long-term cardiac function and are leading productive lives.

Adult↗
PubMed1999

Successful in vitro fertilization of in vivo matured oocytes aspirated laparoscopically from red deer hinds (Cervus elaphus).

Most current protocols of in vitro fertilization in ruminants are based on in vitro maturation of oocytes derived from abattoir material. For application of IVF technology to captive endangered species, however, noninvasive techniques are required which allow repeated collection of oocytes from live females. The aim of this study was to develop a method for embryo production from mature oocytes collected laparoscopically from red deer hinds. Follicular development was synchronized in red deer hinds by the insertion of intravaginal progesterone-releasing devices for 10 d, and ovarian stimulation was induced with 1000 IU, i.m. PMSG 48 h before progesterone device removal. Oocytes were harvested by laparoscopy under xylazine/ketamine sedation 24 h after progesterone device removal and then co-incubated with frozen-thawed red deer spermatozoa for 24 h. In Experiment 1, oocytes and embryos were fixed and stained at different developmental timepoints. Their external morphological changes (cumulus expansion, extrusion of the second polar body and cytokinesis) paralleled their nuclear developmental changes (formation of the 2nd metaphase spindle of meiosis, pronuclear formation and nuclear division, respectively). In Experiment 2, embryos were maintained in vitro until they ceased to undergo cell division. A total of 39 aspiration procedures was carried out on 14 red deer hinds. Forty-four cumulus-oocyte complexes (COC) were aspirated from 95 large Graafian follicles; of these, 27 were classed as mature/nondegenerated on the basis of cumulus/cytoplasmic morphology. Seventeen oocytes cleaved following in vitro fertilization, yielding six 2-cell embryos, six 4-cell embryos, four 8-cell embryos and one 16-cell embryo. The results indicate that laparoscopic aspiration of mature oocytes from hormone-treated females offers a valuable source of genetic material for assisted deer breeding programs.

Animals↗
PubMedDate not supplied

[Device for removing concrements from tubular organs].

Wide use of Dormia's loop for removing the concrements from tubular organs led to development of numerous designs of this device. Search for new designs serves one purpose: decrease the traumatism and risk of injury to the organ during the procedure. The new design is characterized by a longer length of service and is more reliable. It is free from the shortcomings of many known designs used for nonsurgical removal of the concrements from tubular organs, most frequently the ureters and its use is less traumatic.

Calculi↗
PubMed2002

Treatment of unobserved oestrus in a dairy cattle herd with low oestrous detection rate up to 60 days post-partum.

The efficiency of treatments for unobserved oestrus and their effect on the reproductive performance of a dairy cattle herd with low oestrous detection rate till 60 days post-partum (dpp), attributed to the declivous and slippery concrete floor were investigated. The herdsman requested advice in order to improve the mean days open of the herd, but no investments were allowed because a new unit was about to be built. Due to the low oestrus detection rate of the herd, the breeding policy was to inseminate at the first detected post-partum oestrus. Cows were examined at 20-30 dpp to assess uterine involution, ovarian activity and prevalence of reproductive disorders and, at 60 dpp if no previous oestrus was detected. Each examination included palpation per rectum, ultrasound scanning and collection of a blood sample for plasma progesterone (P4) measurement. Cows with unobserved oestrus till 60 dpp were allocated either to a treatment group (n=139) or to a control group (n=139). Three treatments were used: (a) injection of PGF(2 alpha) (PG) upon detection of a corpus luteum (CL; n = 30), cows not observed in oestrus being re-injected 11-12 days later. AI was at oestrus; (b) PRID (n=35) or Crestar (n=74) devices kept in situ for 12 and 9 days, respectively, were associated to an injection of PG and of equine chorionic gonadotrophin (eCG) at device removal. Cows were double-fixed time-inseminated at 48 and 72 h after device removal. All treated cows were examined at 48-72 h after treatment to confirm oestrus. The percentage of cows detected in oestrus up to 60 dpp remained unchanged through the trial (35 and 47% for years before intervention: 1994-95; 51 and 48% for years of intervention: 1996-97). In contrast, the oestrous detection rate was high both in treated (93%) and control (100%) cows. This possibly resulted from an improvement in the oestrous detection efficiency of the herd's personnel and from examination of cows at 48-72 h after treatment. Treated and control cows had identical conception rate (CR; 36 and 37%, respectively) and reproductive performance. However, the mean days open of the herd in 1996 was significantly improved in comparison with previous years (mean +/- SEM: 134 +/- 6, 126 +/- 5, 110 +/- 4 and 114 +/- 5 days, for years 1994, 1995, 1996 and 1997, respectively, p < 0.05, ANOVA). Conception rate to AI up to 40 dpp was significantly reduced, compared with the period between 60 and 100 dpp but, mean days open were significantly improved in cows inseminated up to 60 dpp, compared with thereafter (p < 0.05).

Animals↗
PubMed2000

Initial clinical results with the LifeSite Hemodialysis Access System.

BACKGROUND: The LifeSite Hemodialysis Access System is a subcutaneous valve with an internal pinch clamp that is actuated with a standard 14-gauge dialysis needle, connected to a single lumen cannula placed in the central venous circulation for hemodialysis (HD). METHODS: The LifeSite System (2 valves) was implanted in 23 patients with immediate dual-needle HD use. The cannulas were placed in either the jugular or the subclavian veins and were connected to the subcutaneous valves located in the upper chest area. RESULTS: The mean duration of device survival for the LifeSite System was 6.8 +/- 0.97 months. During this period, the device achieved prescription HD blood flow rates averaging 384.7 +/- 78.5 mL/min with a venous pressure of 223.2 +/- 60.3 mm Hg. After 125 patient months, device removal because of infection was at a rate of 2.5 per 1000 days, and there were no devices removed because of poor flow. The average Kt/V for these patients was 1.51. CONCLUSION: This preliminary clinical study has validated the applicability of the LifeSite Hemodialysis Access System as an access for HD. It is easily implanted and easily used, provides safe and effective dialysis, and is well accepted by patients. It should be especially useful as a bridge device to allow for maturation of a native fistula and will provide an alternative for long-term use in patients in whom a peripheral dialysis access is not feasible.

Adult↗
PubMed2006

Cardiac device infections: getting to the heart of the matter.

PURPOSE OF REVIEW: Use of electrophysiologic devices (permanent cardiac pacemaker and implantable cardioverter/defibrillator) has been increasing. Infection of these cardiac devices is a devastating complication, and medical treatment alone without device removal is often unsuccessful and frequently leads to infection relapse. This article reviews recent publications that address the diagnosis and management of infected electrophysiologic devices. RECENT FINDINGS: Recent studies have shed new light on the incidence, risk factors, management, and outcome of cardiac device infection. Rates of both cardiac device implantation and infection have been increasing, although the rate of increase of cardiac device infection has outdistanced that of implantation and this has had enormous economic and clinical consequences. SUMMARY: The large majority of cardiac device infections are likely due to pocket site contamination at the time of device placement. Hematogenous seeding from a distant focus of infection, particularly due to Staphylococcus aureus, can account for late-onset infection. Although no prospective studies have been conducted to date, management with parenteral antibiotics and complete device removal is the current standard of care. Further study is needed to better define optimal diagnostic and management interventions, particularly in patients with bloodstream infection and no local chest wall or echocardiographic evidence of cardiac device infection.

Heart-Assist Devices↗
PubMed1998

Ambient oxygen concentrations during simulated cardiopulmonary resuscitation.

Oxygen concentrations were measured at 12 points around a cardiopulmonary resuscitation practice mannequin following simulated ventilation with a self-inflating bag, a 'Waters' bag and a ventilator to determine whether increased oxygen concentrations may contribute to the risk of combustion from arcing defibrillator paddles. Ventilation was simulated using either a mask or via a tracheal tube fitted to the airway. The head of the mannequin rested upon a 10-cm-high pillow. Gas sampling took place after 5 min of ventilation with subsequent removal of the ventilatory device and placement on the pillow to the left of the mouth, with the tubing of the device removed to a point 1 m behind the mouth and with the device left connected to the tracheal tube. Gas was sampled after using all devices at oxygen flows of 10l.min-1 and 15l.min-1. Slightly increased oxygen concentrations were noted over the anterior chest after placement of all devices on the pillow at the higher flow. Concentrations of greater than 30% were measured in the left axilla after placement of all devices on the pillow at both flows. No increase in oxygen concentration was seen when the devices were either left connected to the tracheal tube or removed to a distance of 1 m. It would appear that leaving a patient connected to a ventilator poses no increase in risk of fire from ignition of combustible material in an oxygen-enriched atmosphere during defibrillation. Disconnecting any device which continues to discharge oxygen and leaving it on the pillow before defibrillation is dangerous.

Air Pollutants↗
PubMed2003

Pattern and manipulation of follicular development in Bos indicus cattle.

Bos indicus cattle are widespread in tropical regions due to their adaptation to these environments. Although data on reproductive performance have indicated both inferior and superior results for B. indicus cattle, there is little doubt that B. indicus cattle are superior than Bos taurus cattle when they are both kept in tropical or subtropical environments, where stressors like hot temperatures, humidity, ectoparasites and low quality forages are greater. Reproductive endocrinology and oestrus behaviour of the B. indicus cattle have been studied for over 30 years; however, the application of technologies such as real time ultrasonography and Heat-Watch systems has expanded our knowledge on the ovarian follicular-wave dynamics during the oestrous cycle and the time of ovulation. Ovarian follicular dynamics in B. indicus cattle is characterised by the occurrence of two, three or sometimes four waves of follicular development. While dominance is similar to that in B. taurus cattle, maximum diameters of the dominant follicle and CL are smaller than those reported in B. taurus and are probably due to a lower capacity for LH secretion than in B. taurus. Duration of oestrus is approximately 10 h and the interval from oestrus to ovulation is about 27 h. However, the variability in response to prostaglandin F2alpha (PGF) treatments and the difficulty for oestrus detection in B. indicus cattle have limited the widespread application of artificial insemination (AI) and emphasizes the need for treatments that control follicular development and ovulation. Follicular-wave development in B. indicus cattle can be controlled mechanically by ultrasound-guided follicle ablation, or hormonally by treatments with GnRH or oestradiol and progestogen/progesterone in combination. Treatments with GnRH plus PGF and a second GnRH (synchronization protocol known as Ovsynch) or oestradiol benzoate (known as GPE) have resulted in acceptable pregnancy rates after fixed-time AI (FTAI) in cycling cows, but results were lower in heifers and cows in postpartum anoestrus. Alternatively, treatments with oestradiol and progestogen/progesterone releasing devices resulted in synchronous emergence of a new follicular wave, and a second oestradiol or GnRH treatment after device removal resulted in synchronous ovulation and acceptable pregnancy rates to FTAI. Furthermore, oestradiol and progesterone treatments combined with eCG (given at the time of device removal) increased pregnancy rates in suckled B. indicus cows and may be useful for the treatment of cows in postpartum anoestrus. In summary, exogenous control of luteal and follicular development facilitates the application of assisted reproductive technologies in B. indicus cattle by offering the possibility of planning AI programs without the necessity of oestrus detection and without sacrificing the overall results.

Animals↗
PubMed1990

Prediction of flow capability in intravenous infusion systems: implications for fluid resuscitation.

The pressure-flow (P-F) relationship for intravenous infusion systems is nonlinear and may be expressed by the quadratic model P = RLF + RTF2. The flow parameters RL and RT may represent the resistance of laminar and turbulent flow, respectively. In this study pressure and flow were measured, and RL and RT were calculated for several infusion tubings, catheter, and system components. We then developed a technique to identify the relative effect of various devices on achieving the higher flows needed for fluid resuscitation. A typical infusion system was chosen, and the experimentally determined flow parameters RL and RT of its components were used in the quadratic P-F relationship at P = 300 mm Hg. Devices in the infusion system were ranked, using a subtractive algorithm, according to their relative impediment to flow as measured by contribution to the pressure drop. The order of devices removed or replaced, from largest to least pressure drop, was as follows: fluid warmer, 16-gauge catheter, check valve, 14-gauge catheter, standard-bore Y tubing, 12-gauge catheter, and standard-bore stopcock, leaving 10-gauge catheter + wide tubing. Devices with large RT, such as fluid warmers and check valves that produce large pressure drops, should generally be avoided during fluid resuscitation when high flows are needed. A similar ordering of device removal or substitution (largest to least pressure drop) was determined using the traditional but incorrect linear P-F model, P = RF, and the order of devices chosen for elimination was different.(ABSTRACT TRUNCATED AT 250 WORDS)

Fluid Therapy↗