Teflon Catheter Research Articles

Improved survival and ammonia metabolism by intraperitoneal transplantation of microencapsulated hepatocytes in totally hepatectomized rats

We evaluated the effects of intraperitoneal transplantation of microencapsulated hepatocytes in a 3-stage total hepatectomy rat model. A new model of total hepatectomy was created as follows. First, the infrahepatic inferior vena cava was ligated just above the right renal vein. Seven days later, the portal vein was ligated and a portacaval shunt was established using a Teflon catheter over a venipuncture needle. Another 7 days later, total hepatectomy was completed by ligating and dividing the suprahepatic inferior vena cava, the hepatic artery, and the bile duct. Next, 4 x 10(7) hepatocytes (4% of the normal liver hepatocyte mass) isolated from male Wistar rats were microencapsulated within a collagen matrix enveloped by a 3-layer membrane of sodium alginate-poly-L-lysine-sodium alginate copolymer. Capsules containing hepatocytes (diameter, 500-800 microm) and empty capsules (control) were transplanted intraperitoneally 4 days before the total hepatectomy. Survival time and selected blood chemistry concentrations after the total hepatectomy were measured. The capsules were also examined histologically with hematoxylin and eosin staining and modified Gmelin's stain for bile pigments. The survival time was greater in the rats given the microencapsulated hepatocytes than in the control rats (17.3 +/- 3 vs 3.7 +/- 0.1 hours; P <.01). The blood ammonia concentrations increased soon after total hepatectomy but remained significantly lower in the rats with microencapsulated hepatocytes (P <.05). The microcapsules contained numerous viable hepatocytes with abundant bile pigments and no lymphocytic infiltration. Microencapsulated hepatocytes with an ultrathin polymer layer that protects them from inflammatory and lymphocytic reactions may facilitate their ability to function. In this study, 4 x 10(7) hepatocytes significantly prolonged the survival of rats that underwent hepatectomy and supported ammonia metabolism. Further development of this technique may permit its use in patients with hepatic failure.

Extraction of Airway Foreign Body in Adults

Extraction of Airway Foreign Body in Adults

Extraction of Airway Foreign Body in Adults

Extraction of Airway Foreign Body in Adults

External venous shunt as a solution to venous thrombosis in microvascular surgery

We report a case in which venous occlusion occurred after fibular osteocutaneous flap transfer for open tibial fracture. The flap was salvaged using an external venous shunt. The shunt consisted of a Teflon catheter for intravenous infusion, a three-way stopcock, a urokinase-immobilised catheter and a pressurising bag for arterial-pressure monitoring. This method can be used to establish venous drainage when there is no accessible recipient vein. It may improve the success rate of microvascular surgery and extend the indications for surgery.

Importancia de la relación huésped-parásito en estafilococos coagulasa negativa aislados de neonatos

Neonates represent a high risk population for infections by coagulase-negative staphylococci (CNS). To have a better understanding of these process our purpose was to compare the expected result of the bacterium-host interaction given by the neonates' risks factors and the micro-organisms' virulence factors with the condition of infecting or colonising strain that emerge from the diagnosis on the basis of the clinical symptoms. We studied 24 neonates who were submitted to an epidemiological control establishing as risk factors: catheters, vesicle sounds, previous surgery and immunodepressed conditions. In the CNS recovered from clinical samples we determined the following virulence factors: synergistic hemolysis, slime production, adherence to Teflon catheters and hydrophobicity. We found correlation between the clinical diagnosis and the expected result of the bacterium-host interaction in 21 patients (87.5%). Among them, in 8 patients infection didn't occurred in spite of having the micro-organisms 3 from 4 virulence factors since the patients didn't have risk factors. A microbiological study based entirely on identification and treatment can alter the biological context. It is necessary to understand the bacterium-host interaction for an appropriate comprehension of the bacterial diseases.

Treatment of pancreatic pseudocyst and pancreatic abscess using a therapeutic endoscopic ultrasound device.results in 18 patients

The purpose of this study is to evaluate a new technic of cystogastro or duodenostomy for pancreatic pseudo-cyst (PPC) or pancreatic abscesses (PA) entirely guided by endoscopic ultrasound (BUS) and using interventional echoendoscopes. Patients and methods : A cystogastrostomy was performed in 17 patients and a cystoduodenostomy in 1 patient for 7 PPC and II PA. For 16/17 patients, the gastroscopy did not reveal extrinsic compression allowing selection of the puncture site. The origin of the PPC was an alcoholic chronic pancreatitis in 3 cases and an acute pancreatitis due to lithiasis in 2 cases and a hyperlipidemia in 2 cases. The origin of the 11 PA was post-operative acute pancreatitis. The mean size of the 17 pancreatic cysts was respectively 7.5 ern (410 cm).The EUS device was the FG 38X manufactured by Pentax-Hitachi. The FG 38X is an interventional echoendoscope with a working channel of 3.2 mm of diameter .Technique of EUS guided cystogastrostomy : 1/locating the PPC and the contact zone between the gastric wall and the cyst wall. 2/ Color doppler assessment of the stomach wall showed no vascularization in this contact zone 3/ A needle-knife was introduce through the working channel and used to performed EUS guided transgastric puncture of the cyst 4/ The metal part of the needle-knife was withdrawn leaving the teflon catheter in the cyst 5/ A guide wire is introduce through the teflon catheter in the cyst 6/ Under this guide-wire a 6.5 or 7 F naso-cystic drain or a 8.5 F stent was placed within the cyst. Results : No complication occurred. The placement of the nasocystic drain or the 8.5 F stent was successful respectively in 11/12 cases and 5/5 cases. The drain was removed after 5 -10 days and the stent 3 months later. In one case, it was no possible to place the drain and only an aspiration was performed. One recurrence of the 7 pseudo-cyst and 2 relapses of the 11 PA have been observed with a mean follow-up of 24 months (14-32 months).Conclusion : This experience suggest that this technique allows more accurate drainage of the PPC or PA without extrinsic compression with a lower risk of perforation and haemorrhage.

Safety of peripheral intravenous catheters in children.

To determine the overall and per-day risk of complications of short peripheral intravenous (PIV) catheters placed for indefinite periods. During 5 months, general pediatric patients receiving intravenous therapy through short PIV catheters were monitored. Patient and catheter characteristics were recorded, complications were noted, and rolled semiquantitative cultures of removed catheters were performed. Major endpoints were infection and phlebitis. Per-day risk of complications and catheter colonization (>15 colony-forming units) were calculated. University children's hospital. General pediatric ward inpatients with PIV. We studied 642 Teflon catheters in place >24 hours (mean, 3.7 days) in 525 patients. There were no cases of catheter sepsis (0%; 95% confidence interval [CI95], 0%-0.6%), one possible insertion-site infection (0.2%; CI95, 0.004%-0.9%), and seven cases of phlebitis (1.1%; CI95, 0.4%-2.3%). Catheter colonization occurred in 92 (26%) of 348 catheters cultured. Neither the per-day risk of phlebitis nor of catheter colonization increased significantly with placement >3 days. Current guidelines recommend replacement of PIV catheters in adults within 2 to 3 days; no recommendations are made for children. Our findings and those of others indicate that the overall risk of PIV catheter complications in children is extremely low and would not be reduced substantially by routine catheter replacement.

In vitro adherence of Enterococcus faecalis and Enterococcus faecium to plastic biomaterials

In vitro adherence of Enterococcus faecalis and Enterococcus faecium to plastic biomaterials

Sinus Venosus Catheterization for Repeated Vascular Access in the Hybrid Striped Bass

Abstract Placement of vascular cannulae for repeated venous blood sampling has proven to be a useful technique in many fish species. The anatomy and size of the hybrid striped bass (striped bass Morone saxatilis ♀ × M. chrysops ♂) makes this procedure challenging in this species. The sinus venosus was determined to be the best site for catheter placement based on size, accessibility, and ability to stabilize the catheter within it. Catheterization of the sinus venosus with a 20-gauge × 3.8-cm flexible Teflon catheter was unsuccessful because the catheter folded on itself, occluding the lumen. Catheterization with an 18-gauge × 3.8-cm hypodermic needle was also unsuccessful because the sinus wall occluded the needle lumen when negative pressure was applied. However, 18-gauge × 3.8-cm intravascular needles remained patent in free-swimming fish for 2 weeks without major complications. An external fixation device to prevent migration of the catheter out of the sinus venosus and laceration of the sinus wall du...

Infusion Phlebitis in Patients With Acute Pneumonia: A Prospective Study

To prospectively assess the relative risk for phlebitis in a series of consecutive patients with pneumonia and to identify risk factors that predict an increased risk for phlebitis. Internal medicine department of a tertiary teaching hospital. Seven hundred sixty-six consecutive patients with acute pneumonia receiving IV therapy. Only the first catheter was taken into account. There were 308 short lines (a 51-mm, 18-gauge Teflon catheter); 307 midsized lines (a 28-cm, 16-gauge polyvinyl chloride catheter); and 151 long lines (71-cm, 14-gauge plain polyurethane catheter). Eighteen variables were prospectively evaluated in an open, nonrandomized study for their contribution to the occurrence of phlebitis. The overall phlebitis rate was 39%. Phlebitis developed in 53% of patients with short lines, in 41% of patients with midsized lines, and in 10% of patients with long lines, and these catheters remained in place an average (+/- SD) of 3.0+/-2.4 days, 4.6+/-3.4 days, and 7.8+/-6.6 days, respectively. The variables that influenced the development of phlebitis, as determined by multivariate analysis, were the following: type of catheter; blood hemoglobin levels; and IV therapy with either corticosteroids or erythromycin. According to our data, when the use of a catheter is expected to be required for < or = 36 h, a short line can be used. If a longer duration is expected, a longer line is warranted. Ours is the first study in which the relationship between blood hemoglobin levels and phlebitis has been reported. Because the use of intravascular devices is increasingly common, a more complete knowledge of the factors that influence their acceptance has become essential.

Bacterial biofilms and catheters in experimental urinary tract infection

Employing in vitro and in vivo models of catheter-associated infection, biofilm formation of Pseudomonas aeruginosa in artificial urine and bactericidal activity of several classes alone or in combination with a macrolide antibiotic were investigated. In the course of continuous urine flow, bacteria adherent to a Teflon catheter formed microcolonies at 6 h and a biofilm at 24 h. Following 24 h of urine flow, the thickness and the density of the biofilm increased to about 20 μm and 10 8 cfu/mm 3, respectively. Of the antibiotics examined, the fluoroquinolones showed the most potent bactericidal activity against the P. aeruginosa biofilms. However, those antibiotics were not always potentiated by the combination with a macrolide antibiotic.

In vitro bactericidal activities of beta-lactamases, amikacin, and fluoroquinolones against pseudomonas aeruginosa biofilm in artificial urine

Objectives. To compare bactericidal activities of antimicrobial agents against Pseudomonas aeruginosa biofilms by employing an in vitro model of catheter-associated infection because such infections are refractory to antimicrobial treatment.Methods. Bactericidal activities of piperacillin (PIPC), ceftazidime (CAZ), panipenem (PAPM), amikacin (AMK), ciprofloxacin (CPFX), and levofloxacin (LVFX) were examined against a P. aeruginosa biofilm generated on a Teflon catheter in artificial urine. The colony-forming activities of biofilm bacteria were determined for 48 hours during the treatment with each drug at concentrations of 1 up to 128 times the minimal bactericidal concentration (MBC), and time-kill curves were constructed by plotting the viable cell counts against time.Results. Although CAZ was more bactericidal to the biofilm bacteria than PIPC, the biofilm bacteria still remained on the catheter during CAZ treatment at a concentration 128 times the MBC for 48 hours. Biofilm bacteria were completely eradicated within 48 hours by treatment with PAPM and AMK at a concentration 64 and 128 times the MBC, respectively. Both CPFX and LVFX eradicated biofilm bacteria completely by 24 hours at a concentration 32 times the MBC.Conclusions. These results indicate that fluoroquinolones have the most potent bactericidal activity against the P. aeruginosa biofilm generated in urine.

CHANGES IN LACTATE AND VENTILATION THRESHOLD WITH INCREASING HYPOBARIC HYPOXIA

1084 This investigation was conducted to examine if lactate and ventilation thresholds change proportionately under increasing hypobaric hypoxia. 10 male and 8 female volunteers served as subjects for this investigation. Subjects each completed four maximal graded exercise test on a cycle ergometer at each of 760, 682, 632, and 566 Torr in a hyper/hypobaric chamber. Expired gas was collected every thirty seconds and analyzed with an automated gas analysis system (Jaeger). Blood samples were collected every minute during exercise through a teflon catheter inserted into a vein in the antecubital space. Blood lactate concentration was determined using spectrophotometric methods. Lactate threshold (LT) was identified by plotting the log of the lactate concentration against VO2, and then applying bisegmental regression lines to the data. The ventilation threshold (VT) was identified by plots of the ventilation equivalents for oxygen (VE/VO2) against VO2. The first incremental increase in VE/VO2 was specified as the ventilation threshold. A two-way ANOVA was used to identify significant differences in the thresholds. Where necessary specific differences were identified using the specific error term for the analysis. Statistical analysis revealed a significant interaction between the threshold type and altitude (p<.05) for both VO2 (L/min.) and%VO2max. Subsequent analysis showed VO2 at LT to be significantly lower than VT at 632 and 566 Torr (1.82±.53 vs 2.36±.53 and 1.65±.52 vs. 2.11±.41 L/min). While a significant interaction was found for%VO2max no significant differences could be found between the means (p>.05). Based on these findings we suggest that VT may not be adequate for estimating LT at altitude, and that the VT and LT may not be as metabolically connected as once thought.

Double-helix coil for occlusion of large patent ductus arteriosus: evaluation in a chronic lamb model.

We sought to evaluate the efficacy and tissue reaction of a new miniature interventional device for occlusion of large patent ductus arteriosus (PDA) in a neonatal lamb model. A variety of devices are used to close PDAs by interventional measures. Spring coils found to have a high cumulative occlusion rate have thus far been limited to smaller PDAs because of the physical limitation of grip forces. Memory-shaped double-cone stainless steel coils with enhanced stiffness of the outer rings by a double-helix configuration were mounted on a titanium/nickel core wire. A snap-in mechanism attaches the coil to the delivery wire, allowing intravascular coil retrieval and repositioning. The system was placed through a 4F or 5F Teflon catheter. A chronic lamb model (n = 8) of PDA (>5 mm) was used in which ductus patency was secured by a protocol of repetitive angioplasty procedures. The animals were killed after 1 to 181 days, and the ductal region was examined by inspection as well as by light and electron microscopy. Placement of the coils within the PDA was possible in all lambs. Before final detachment, the coils were retrieved or repositioned, or both, up to 12 times. In all but one animal the ductus was closed within 6 days after the procedure. The coils caused no infections or aortic and pulmonary artery obstruction. Histologic and electron microscopic studies revealed endothelial coverage of the implants but no foreign body reaction or local or systemic inflammation or erosion of the implant. The device effectively closed large PDAs in our model and may overcome the previous limitations of coils. Clinical trials are indicated.

Lactiferous duct microendoscopy

SummaryIt is possible to minimise the invasiveness of diagnosis in cases of pathological nipple secretion by examining the lactiferous duct using microfibre optics. In this study, the visualisation of the internal lactiferous duct was tested on an animal model and in humans. Flexible fibre-endoscopes, with diameters of 0.50 and 0.75 mm (3000 and 6000 pixel), and a semi-rigid fibre-endoscope with a diameter of 0.85 mm (6000 pixel) were tested in conjunction with Teflon catheters and rigid steel microtrocars of 0.8, 1.1 and 1.2 mm outer diameter. The lactiferous duct system could be visualised reproducibly from the orificium of the ductus mamillaris over all its ramifications to its endings in complete expansion.

Evaluation of techniques for measuring negative intramuscular pressures in humans.

Negative external pressure has been used previously in experiments on the blood circulation in humans and is currently being considered as a counter-measure to the musculoskeletal deconditioning which occurs during the exposure to microgravity. Intramuscular pressure (IMP) measurement is an important tool for determining the effectiveness of the transmission of negative pressure. Therefore two IMP techniques, a fibre optic transducer-tipped catheter and a fluid-filled teflon catheter with side holes, were evaluated using laboratory and human tests for measuring negative pressures. For the laboratory tests, both catheters were placed inside a lower leg negative pressure (LLNP) chamber and pressures of 0, -20, -50, -80, -100 and back to 0 mmHg were applied. Both catheters measured pressures equally and remained stable over 1 min at all pressure levels. When the teflon catheter was infused at rates commonly used for IMP recordings at normal atmospheric pressures, the drip rate at the catheter tip increased inversely with the magnitude of negative pressure. The cables and pressure tubings of the catheters within the LLNP chamber were not affected by the negative pressures. For tests in humans, the catheters were inserted side by side in the tibialis anterior muscle in eight legs of four human volunteers. The leg was placed in the LLNP chamber and pressures of 0, -20, -50, -80 and back to 0 mmHg were applied. The teflon catheter was used without infusion. Both catheters measured IMP similarly at rest and both remained stable over 1 min at all pressure levels; also the IMP during muscle contractions and immediately following contractions was similarly recorded by both catheters. We concluded that both catheter systems are suitable for recording negative pressures over a wide range. As is the case with recordings at normal atmospheric pressures, the fibre optic transducer-tipped catheter system may be preferred when recording IMP in a negative pressure environment when complex limb movements are involved.

Assessment of the content of selected trace elements in serum of term and pre-term newborns by inductively coupled plasma mass spectrometry

A method for the determination of 14 trace and ultra-trace elements (Al, Cd, Co, Cu, Li, Mn, Mo, Ni, Pb, Pt, Rb, Sb, Se and Zn) in serum of newborns by inductively coupled plasma mass spectrometry (ICP-MS) with ultrasonic nebulization is described. Cord blood samples were collected from term and pre-term newborns by means of a teflon catheter within 24 h from delivery. The eligibility criteria adopted in this study require that only “normal” (i.e. fully representative of their specific conditions) subjects be selected for blood collection. From this standpoint, pre-term newborns suffering only from diseases derived from their status, i.e. really representative of the group under investigation, were included in the study. After centrifugation, serum aliquots were stored in metal-free plastic test tubes at −20 °C until analysis. Sample treatment was kept to a minimum, i.e. serum samples were diluted 20–50-fold with 0.14 M HNO 3 and spiked with suitable amounts of Rh and Tl, the internal standards, to account for nebulization effects and for instability of nebulization and ionization. To minimize the effects of matrix interferences, blanks and calibrants were prepared from synthetic solution containing the same major components as the real sample solutions. The analytical method adopted, i.e. ICP-MS determination combined with ultrasonic nebulization, turned out to be fully suited to the aim of this study. Experimental data were statistically analyzed by parametric and non-parametric tests in order to assess tentative reference ranges of elemental concentrations. To this end, newborns were grouped by gestational age and body weight at the delivery. Results allow tentative reference values to be assessed for the above-mentioned elements in serum of newborns, with the only exception of Pt, which was below the detection power of the technique.

Birth of a western lowland gorilla (Gorilla gorilla gorilla) following in vitro fertilization and embryo transfer.

A 21-year-old multiparous female exhibiting 31-41 day menstrual cycles was given hFSH (225 IU/day, Metrodin 75, from cycle day 3 through 9 (menses = day 1) and hCG (10,000 IU, Profasi, on day 10 to stimulate follicular development. At 35 h after hCG, under isoflurane (AErrane) anesthesia, follicles were aspirated by controlled suction under transvaginal ultrasound guidance. Metaphase II oocytes (n = 11) were placed in modified human tubal fluid (mHTF, 100 microliters) medium under oil at 37 degrees C in humidified 5% CO2. Frozen semen, collected by voluntary ejaculation, was thawed (70 degrees C H2O bath, 6 sec), diluted slowly, centrifuged, and resuspended in mHTF, and 160,000 motile spermatozoa/ml were added at 6 h after oocyte recovery. At 21 h postinsemination (p.i.) eight oocytes were at the two-cell stage, five were cryopreserved, and three were cultured to the six- to eight-cell stage in mHTF with granulosa cells before transcervical uterine transfer at 47 h p.i. using a Teflon catheter. Micronized progesterone (400 mg/d) was orally administered for 10 weeks posttransfer (p.t.). Ultrasound examination revealed a single fetus at 15 weeks p.t., and unassisted delivery of a live 1.37 kg female infant occurred at 29 weeks. Am. J. Primatol. 41:247-260, 1997.

Ossicular vibration changes associated with pressure changes in inner ear and cerebrospinal fluid in guinea pigs

The effects of increase in the inner ear and cerebrospinal fluid (CSF) pressures on the vibration of the ossicular chain were studied in guinea pigs by using a laser doppler vibrometer. Velocity of the malleus umbo and that of the incus long crus in response to a constant sound stimulus of 90dB SPL at the tympanic membrane were measured at 13 frequencies between 0.125 kHz and 10 kHz. Loading pressures to the inner ear and the CSF were adjusted by changing the height of a saline bottle hooked up to the respective site by a 24G Teflon catheter. The pressure was monitored with a pressure transducer placed in the catheter. Positive and negative pressure loads to the inner ear decreased the velocity of the umbo at low and high frequencies. The maximum change was 4.7 dB at 0.125 kHz with a positive pressure load of 400 mmH2O. Similar results were obtained for the umbo and the long crus by a positive pressure load to the CSF, with the exception that the umbo velocity showed no change at higher frequencies. These results suggest that the inner ear and CSF pressure changes affect not only the function of the organ of Corti but also the vibration of the ossicular chain. These changes occurred mainly at lower frequencies.

Midline Catheterization in Hospitalized Patients

Letters15 October 1996Midline Catheterization in Hospitalized PatientsLeonard A. Mermel, DO, ScM, Stephen Parenteau, MS, and Sen Mee Tow, BSN, CRNILeonard A. Mermel, DO, ScMRhode Island Hospital, Providence, RI 02903Search for more papers by this author, Stephen Parenteau, MSRhode Island Hospital, Providence, RI 02903Search for more papers by this author, and Sen Mee Tow, BSN, CRNIRhode Island Hospital, Providence, RI 02903Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-125-8-199610150-00020 SectionsAboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail IN RESPONSE:Manzella and colleagues did not observe the adverse reactions that we and others [1] described; however, Moorcroft and associates did, and they noted a similar incidence rate. Regarding Dr. Evans' comments, the Teflon catheters were 0.75 to 1.25 inches long and were inserted during the study period in hospitalized patients by the same nursing group that inserted the Landmark catheters.Regarding the comments of Drs. Terr and Bloch, our patients' symptoms resembled anaphylactoid reactions associated with first use of cuprophane dialyzers; fewer than 20% had urticaria or angioedema, and symptoms resolved despite continued use of the device [2]. ...