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Catheter Tip (catheter + tip)
Terms modified by Catheter Tip Selected AbstractsThe Effect of Ablation Electrode Length and Catheter Tip to Endocardial Orientation on Radiofrequency Lesion Size in the Canine Right AtriumPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2002RODRIGO C. CHAN CHAN, R.C., et al.: The Effect of Ablation Electrode Length and Catheter Tip to Endocardial Orientation on Radiofrequency Lesion Size in the Canine Right Atrium. Although the determinants of radiofrequency lesion size have been characterized in vitro and in ventricular tissue in situ, the effects of catheter tip length and endocardial surface orientation on lesion generation in atrial tissue have not been studied. Therefore, the dimensions of radiofrequency lesions produced with 4-, 6-, 8-, 10-, and 12-mm distal electrode lengths were characterized in 26 closed-chested dogs. The impact of parallel versus perpendicular catheter tip/endocardial surface orientation, established by biplane fluoroscopy and/or intracardiac echocardiography, on lesion dimensions was also assessed. Radiofrequency voltage was titrated to maintain a steady catheter tip temperature of 75°C for 60 seconds. With a perpendicular catheter tip/tissue orientation, the lesion area increased from 29 ± 7 mm2 with a 4-mm tip to 42 ± 12 mm2 with the 10-mm tip, but decreased to 29 ± 8 mm2 with ablation via a 12-mm tip. With a parallel distal tip/endocardial surface orientation, lesion areas were significantly greater: 54 ± 22 mm2 with a 4-mm tip, 96 ± 28 mm2 with a 10- mm tip and 68 ± 24 mm2 with a 12-mm tip (all P < 0.001 vs perpendicular orientation). Lesion lengths and apparent volumes were larger with parallel, compared to perpendicular tip/tissue orientations, although lesion depth was independent of catheter tip length with both catheter tip/tissue orientations. Electrode edge effects were not observed with any tip length. Direct visualization using intracardiac ultrasound guidance was subjectively helpful in insuring an appropriate catheter tip/tissue interface needed to maximize lesion size. Although atrial lesion size is critically dependent on catheter tip length, it is more influenced by the catheter orientation to the endocardial surface. This information may also be helpful in designing electrode arrays for the creation of continuous linear lesions for the elimination of complex atrial tachyarrhythmias. [source] Numerical Simulation of Thrombus Aspiration in Two Realistic Models of Catheter TipsARTIFICIAL ORGANS, Issue 4 2010Giancarlo Pennati Abstract Thrombus aspiration catheters are devices used to remove a blood clot from a vessel, usually prior to angioplasty or stent implantation. However, in vitro results showed that the use of different commercial devices could produce very different thrombus removals, suggesting a primary dependence on the distal tip configuration of the catheter. A computational methodology based on realistic catheter tip modeling was developed to investigate the factors affecting the thrombus suction. Two different designs were considered, either with a single central lumen or a combination of central and side holes. First, steady-state aspiration of distilled water from a reservoir was simulated and compared with experimental tests. Subsequently, the aspiration of a totally occlusive thrombus, modeled as a high viscous fluid, was simulated solving a complex two-phase (blood and thrombus) problem. In particular, the benefit of additional openings was investigated. Good matching between the steady-state experimental and numerically simulated hydraulic behaviors allowed a validation of the numerical models. Numerical results of thrombus aspiration showed that the catheter with central and side holes had a worse performance if compared with the single central lumen catheter. Indeed, the inlets in contact with both blood and thrombus preferentially aspirate blood due to its much lower viscosity. This effect hindered the aspiration of thrombus. The amount of aspirated thrombus highly depends on the complex, two-phase fluid dynamics occurring across the catheter tips. Results suggested that location of additional holes is crucial in the catheter aspiration performance. [source] Intravenous catheter infections associated with bacteraemia: a 2-year study in a University HospitalCLINICAL MICROBIOLOGY AND INFECTION, Issue 5 2004M. Paragioudaki Abstract The aim of this retrospective study was to assess the incidence and aetiology of central and peripheral venous catheter (C/PVC) infections during a 2-year period (1999,2000) and to determine the susceptibility of isolated microorganisms to various antimicrobial agents. Catheter tips were processed using the semiquantitative method and blood cultures were performed with the BacT/Alert automated system. Antibiotic susceptibilities were performed by disk agar diffusion and MICs were determined by Etest, according to NCCLS standards. During the study period, samples from 1039 C/PVC infections were evaluated, yielding 384 (37.0%) positive cultures. Blood cultures were also available from 274 patients, of which 155 (56.6%) yielded the same microorganism as from the catheter. No bloodstream infections were detected in 104 C/PVC-positive cases. Methicillin-resistant coagulase-negative staphylococci were the most frequent isolates, followed by Gram-negative bacteria, especially Pseudomonas aeruginosa. Resistance to glycopeptides among staphylococci and enterococci was not detected, whereas 60% of Gram-negative bacilli were resistant to ,-lactams. [source] Continuous peripheral nerve block catheter tip adhesion in a rat modelACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2006C. C. Buckenmaier III Background:, Continuous peripheral nerve block (CPNB) has been used effectively in combat casualties from Iraq and Afghanistan to provide surgical anesthesia and extended duration analgesia during evacuation and convalescence. Little information is available concerning catheter tip tissue reaction with prolonged use. Methods:, Forty-eight male Sprague-Dawley rats were assigned (12 per group) to one of four catheter tip designs provided by Arrow International: group A, 20-gauge catheter with three side-holes and a bullet-shaped tip; group B, 19-gauge StimuCathÔ catheter with coiled omni-port end with hemispherical distal tip; group C, 19-gauge catheter with single end-hole in conducting tip; group D, 19-gauge catheter with closed conducting tip with four side-holes. Following laparotomy, a randomly assigned catheter tip was sutured to the parietal peritoneal wall with the tip extending between experimental injuries created on the abdominal wall and cecum. After 7 days in situ, the catheter tips were removed from the adhesion mass using a force gauge, and the grams of force needed for removal were recorded. Results:, The mean force ± standard deviation values were 1.09 ± 1.21 g for group A, 21.20 ± 30.15 g for group B, 0.88 ± 1.47 g for group C and 1.60 ± 2.50 g for group D. The variation of each catheter group mean force compared with that of group B was significant (P < 0.05). There was no significant difference in adhesion force between groups A, C and D. Conclusions:, These results suggest that the manufactured design of a CPNB catheter tip can contribute to the adhesion of the tip in an intense inflammatory environment. This finding may have important clinical implications for CPNB catheters left in place for extended periods of time. [source] Thoracic epidural catheters via the caudal and lumbar approaches using styletted multiple port catheters in pediatric patients: a report of three casesACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2006B. C. H. Tsui Advancing catheters from the lumbar and caudal epidural spaces to the thoracic level has been reported to be an alternative to the direct thoracic approach. However, as children grow, the threading of catheters in the epidural space becomes increasingly difficult. This report describes three cases of thoracic epidural placement using a multiport catheter threaded from the caudal and lumbar spaces using electrical stimulation guidance. In the first case, a multiport catheter was threaded 22 cm from the lumbar space to T8 following a failed attempt with a single-port catheter in a 9-year-old boy scheduled to undergo a right nephrectomy. In the second case, a multiport catheter was threaded 26 cm from the caudal space to T9 in a 3-year-old girl undergoing fundoplication. In the last case, a multiport catheter was inserted at the completion of a fundoplication in a 2-year-old girl after it had been confirmed that the single-port catheter inserted prior to surgery had not advanced to the desired thoracic level. The multiport catheter was threaded 17 cm without resistance from the caudal space to T9. In all cases, electrical stimulation was used to confirm the location of the catheter tip at the time of insertion. The position of the catheters was later confirmed by X-ray. The multiport catheter incorporates a stylet, which extends to a closed distal tip, within a catheter body that ejects fluid from three lateral holes in a direction perpendicular to the advancing catheter. These properties may facilitate the reliable advancement of catheters in the epidural space. [source] Epidural blood patch for treatment of spontaneous intracranial hypotensionACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2002N. Waguri Spontaneous intracranial hypotension is an uncommon disease caused by cerebrospinal fluid leakage. We reported a case of a 42-year-old male with postural headache who was diagnosed as having spontaneous intracranial hypotension. His headache did not completely improve by conservative therapies, so he underwent an autologous epidural blood patch. The site of cerebrospinal fluid restoration was identified at the level from the C2 to Th7 epidural space by 111In-DPTA cisternography and computed tomography coupled with myelography, and cervical EBP was performed. Because cerebrospinal fluid drops from the catheter, it is useful to identify the location of the catheter tip under contrast injection X-ray. Rapid and dramatic relief from the headache was obtained, and no serious complications occurred. [source] Coiling of lumbar epidural cathetersACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2002Y. J. Lim Background: The difficulties in threading an epidural catheter to vertebral levels remote to the puncture level have been well documented. This study was undertaken to determine the length that a single orifice epidural catheter can be threaded into the lumbar space without coiling (coiling length), and whether this is affected by the direction of the epidural needle bevel. Methods: Forty-five young male patients scheduled for surgery under epidural analgesia were enrolled. The epidural space was identified using a midline approach at the L2,3 or L3,4 interspace with the loss of resistance to air technique. A 19-G single-orifice epidural catheter (Flextip PlusTM, Arrow International, Inc, Reading, PA, USA) was inserted through a Tuohy needle oriented either cephalad (n=20) or caudad (n=25). During insertion, the path and the position of the catheter tip was determined by fluoroscopy using iohexol dye. Results: The median coiling length was 2.8 cm, ranging from 1.0 to 8.0 cm. Only 13% of epidural catheters could be threaded 4 cm beyond the tip of the needle without coiling. No significant difference was found in coiling length between the cephalad group (2.9 cm) and the caudad group (2.5 cm). Conclusion: This study demonstrates that coiling length is independent of whether the bevel of the Tuohy needle is directed cephalad or caudad. We recommend that an optimal insertion depth of an end-hole single orifice catheter is 3 cm. [source] Catheter Tip Granuloma Associated with Sacral Region Intrathecal Drug AdministrationNEUROMODULATION, Issue 4 2003Fernandez Julius MD Abstract Spinal cord compression from catheter tip granulomatous masses following intrathecal drug administration may produce devastating permanent neurologic deficits. Some authors have advocated intrathecal catheter placement below the conus medullaris to avoid the possibility of spinal cord involvement. Multiple cases of catheter tip granulomas in the thoracolumbar region have been reported. We present a unique case of a sacral region catheter tip inflammatory mass producing permanent neurologic deficits. A 71-year-old white male with a diagnosis of failed back surgery syndrome was referred to the senior author for evaluation. After more extensive conservative therapy, including spinal cord stimulation, failed to yield adequate pain relief, he was offered implantation of an intrathecal pump for opioid administration. Excellent pain relief was achieved in the postoperative period; however, three years after implantation, he presented with progressive saddle anesthesia and bowel/bladder incontinence. Magnetic resonance imaging demonstrated a space occupying lesion associated with the catheter tip. The patient underwent emergent second level complete sacral laminectomy with partial resection of an intradural extra-axial mass and removal of intrathecal catheter. At discharge, the patient had no restoration of neurologic function. Histologic examination of the mass confirmed a sterile inflammatory mass. It has been suggested that intrathecal catheters be placed below the conus medullaris to avoid the possibility of spinal cord involvement. We present an unusual case documenting devastating permanent neurologic deficits from a catheter tip granuloma in the sacral region. [source] Caudally threaded thoracic epidural catheter as the sole anesthetic in a premature infant and ultrasound confirmation of the catheter tipPEDIATRIC ANESTHESIA, Issue 8 2009Donald Schwartz No abstract is available for this article. [source] Cephalad origin of the superior vena cava and the level of the central venous catheter tip on chest radiographsPEDIATRIC ANESTHESIA, Issue 1 2005TOSHIMI ARAI MD Summary Background :,There are suggested radiographic landmarks for the lower margin of the superior vena cava (SVC), but none for the cephalad origin of the SVC in children. Therefore, we determined the cephalad origin of the SVC in relation to the level of thoracic vertebrae in children. Methods :,Sixty-five patients (2,96 months) scheduled for routine diagnostic cardiac catheterization were the subjects of the study. Vena cavogram was obtained. The crossing point between the SVC and the innominate vein was considered as the cephalad origin of the SVC, then this point was related to the level of the thoracic vertebra as a radiographic landmark. Results :,In approximately 90% of the patients studied the proximal origin of the SVC was situated above the level of Th4/5 interspace. Conclusion :,We would like to suggest that the position of the tip of central venous line, when inserted via the right internal jugular vein, should optimally be at the level of Th4/5 interspace on the postoperative chest radiograph. [source] Detection of peripherally inserted central catheter occlusion by in-line pressure monitoringPEDIATRIC ANESTHESIA, Issue 7 2002Junichi Arai MD SummaryBackground: Peripherally inserted central catheters (PICC) are being increasingly used in neonatal practice. Their use is not without technical difficulty. This report describes the use of continuous pressure monitoring to detect catheter occlusion in critically ill neonates. Methods: In-line venous pressure of the PICC line was monitored by pressure transducer in neonates; 28-gauge 20 cm PICC or 29-gauge 25 cm PICC were used. Results: In-line pressure of the PICC was monitored 64 times in 50 neonates. Increases in the in-line pressure were observed when the catheter tip was against the vessel wall and the catheter was obstructed partially or completely. Decreases were observed when the infusion syringe was changed and when an inappropriate infusion rate was set. Two infants experienced marked variations of blood pressure due to intermittent catheter occlusion of the tip against the vessel wall. These infants were receiving dopamine via a PICC line. Conclusions: In critically ill infants, in-line pressure monitoring of the PICC is helpful in detecting the occlusion of the catheter. [source] Staphylococcus aureus as source of catheter-related bloodstream infection evaluated by PFGE and rep-PCR typing in a Brazilian hospital,APMIS, Issue 11 2008GERALDO SADOYAMA Staphylococci are a common cause of catheter-related bloodstream infection (CR-BSI), and epidemiological typing is an important tool for effective infection control. This study evaluated by PFGE and rep-PCR whether Staphylococcus aureus strains isolated from skin and catheter tips were related to specimens isolated from blood. A prospective observational study, carried out in a clinical surgical ward at a Brazilian hospital between September 2000 and November 2002, investigated non-tunneled central venous catheters from 179 patients. S. aureus isolates were mainly obtained from blood (41.4%), while coagulase-negative staphylococci strains were more often isolated from the skin at the catheter insertion site (49.7%) and from the catheter tip (57.5%). Among the 21 strains isolated from 9 patients at 2 or 3 sites simultaneously, 9 were methicillin-resistant S. aureus (MRSA) and 12 were methicillin-susceptible S. aureus (MSSA). Seven patients harbored the same S. aureus strain isolated from the skin, blood and/or catheter tip cultures. MRSA isolates belonged to one PFGE pattern (type A- subtypes A1, A2 and A3), and to two rep-PCR patterns (a and b). MSSA isolates were distinguished in five PFGE (B to F) and in three rep-PCR (c, d and e) patterns. Both PFGE and rep-PCR methods indicated that the skin at the catheter insertion site was the origin of CR-BSI caused by S. aureus. [source] Venous Pressure Regulation During Pulsatile Extracorporeal Life SupportARTIFICIAL ORGANS, Issue 10 2008Seong Wook Choi Abstract During the use of pulsatile extracorporeal life support (pulsatile-ECLS), the patient's venous pressure near the inlet venous catheter tip must be monitored to maintain sufficient blood flow and to prevent vein collapse. However, direct measurement of the venous pressure and the estimate of suction using measured blood inflow and prepump pressure are not practical because of setup difficulties during emergency treatments and in cardiovascular operations. In this article, we describe a new method for estimating the venous pressure that can be implemented in the controller of the pulsatile-ECLS system, the T-PLS. It uses real-time measurement of the electric current and actuator motion. The current waveform of the T-PLS is used to determine the outflow amount and the volume remaining in the pulsatile pumps. Previously measured values of the pulsatile-ECLS compliance and the hemodynamic resistance along the inflow path are used to evaluate venous pressure with estimated blood flow. Estimated prepump pressure, inflow, and venous pressure were compared to the measured data in a series of in vitro experiments. The estimated venous pressure was used to avoid vein collapse and to increase the reliability in animal experiments. [source] Incidence, spectrum and antibiotic sensitivity pattern of bacterial infections among patients with acute pancreatitisJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 9 2001Pramod Kumar Garg Abstract Background and Aim: Secondary infection of pancreatic necrotic tissue and peripancreatic fluid is a serious complication of acute pancreatitis resulting in significant morbidity and mortality. The aim of this study was to find out the spectrum of bacterial infections, and their antibiotic sensitivity pattern in patients with acute pancreatitis. Methods: All consecutive patients with acute pancreatitis were studied prospectively. Detailed investigations were carried out to identify bacterial infections and their antibiotic sensitivities in patients with suspected infection. These investigations included cultures of various body fluids, throat swabs, indwelling cannula and catheter tips. Pancreatic tissue was obtained by using needle aspiration or at surgery for Gram's stain, culture and sensitivity. All cultures were repeated until the presence of infection was confirmed or excluded. Results: A total of 169 patients with acute pancreatitis were studied during the period between January 1997 and June 2000 (mean age 41.3 years; 116 males and 53 females). Of the 169 patients, 63 had infections at various sites. A total of 80 cultures were positive, and 12 different bacterial isolates were cultured from samples taken from these 63 patients. Polymicrobial infection was seen in 32% of patients. Twenty-four patients had a confirmed pancreatic infection. Blood cultures had a growth of organisms in 19 patients, with evidence of ongoing or worsening pancreatitis, thus raising a strong suspicion of infected necrosis in them. The commonest organisms were Escherichia coli from 20 cultures and Pseudomonas aeruginosa from 18 cultures. The antibiotic sensitivity pattern showed that most bacteria were sensitive to third generation cephalosporins and quinolones; notably among them were cefotaxime, ceftazidime, and ciprofloxacin. Conclusion: Bacterial infections were seen in 37% of patients with acute pancreatitis. The commonest organisms were Pseudomonas aeruginosa and Escherichia coli. Most bacterial isolates were sensitive to third generation cephalosporins and quinolones. [source] Cervical epidural analgesia via a thoracic approach using nerve-stimulation guidance in adult patients undergoing total shoulder replacement surgeryACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2007B. C. H. Tsui Background:, Continuous cervical epidural anesthesia can provide excellent peri- and post-operative analgesia, although several factors prevent its widespread use. Advancing catheters from thoracic levels to the cervical region may circumvent these barriers, provided they are accurately positioned. We hypothesize that guiding catheters from thoracic to cervical regions using low-current epidural stimulation will have a high success rate and enable excellent analgesia in adults undergoing total shoulder arthroplasty. Methods:, After Institutional Review Board approval, adult patients were studied consecutively. A 17-G Tuohy needle was inserted into the thoracic epidural space using a right paramedian approach with loss of resistance. A 20-G styletted epidural catheter, with an attached nerve stimulator, was primed with saline and a 1,10 mA current was applied as it advanced in a cephalad direction towards the cervical spine. Muscle twitch responses were observed and post-operative X-ray confirmed final placement. After a test dose, an infusion (2,8 ml/h) of ropivacaine 2 mg/ml and morphine 0.05 mg/ml (or equivalent) was initiated. Verbal analog pain scale scores were collected over 72 h. Results:, Cervical epidural anesthesia was performed on 10 patients. Average current required to elicit a motor response was 4.8 ± 2.0mA. Post-operative X-ray of catheter positions confirmed all catheter tips reached the desired region (C4,7). The technical success rate for catheter placement was 100% and excellent pain control was achieved. Catheters were positioned two to the left, four to the right and four to the midline. Conclusion:, This epidural technique provided highly effective post-operative analgesia in a patient group that traditionally experiences severe post-operative pain and can benefit from early mobilization. [source] Continuous peripheral nerve block catheter tip adhesion in a rat modelACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2006C. C. Buckenmaier III Background:, Continuous peripheral nerve block (CPNB) has been used effectively in combat casualties from Iraq and Afghanistan to provide surgical anesthesia and extended duration analgesia during evacuation and convalescence. Little information is available concerning catheter tip tissue reaction with prolonged use. Methods:, Forty-eight male Sprague-Dawley rats were assigned (12 per group) to one of four catheter tip designs provided by Arrow International: group A, 20-gauge catheter with three side-holes and a bullet-shaped tip; group B, 19-gauge StimuCathÔ catheter with coiled omni-port end with hemispherical distal tip; group C, 19-gauge catheter with single end-hole in conducting tip; group D, 19-gauge catheter with closed conducting tip with four side-holes. Following laparotomy, a randomly assigned catheter tip was sutured to the parietal peritoneal wall with the tip extending between experimental injuries created on the abdominal wall and cecum. After 7 days in situ, the catheter tips were removed from the adhesion mass using a force gauge, and the grams of force needed for removal were recorded. Results:, The mean force ± standard deviation values were 1.09 ± 1.21 g for group A, 21.20 ± 30.15 g for group B, 0.88 ± 1.47 g for group C and 1.60 ± 2.50 g for group D. The variation of each catheter group mean force compared with that of group B was significant (P < 0.05). There was no significant difference in adhesion force between groups A, C and D. Conclusions:, These results suggest that the manufactured design of a CPNB catheter tip can contribute to the adhesion of the tip in an intense inflammatory environment. This finding may have important clinical implications for CPNB catheters left in place for extended periods of time. [source] Cryoablation for Atrioventricular Nodal Reentrant Tachycardia in Young Patients: Predictors of RecurrencePACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2008NIKHIL K. CHANANI M.D. Background: Recurrence rates of atrioventricular nodal reentry tachycardia (AVNRT) after cryoablation continue to remain high despite excellent initial success rates. Our objective was to evaluate the clinical outcomes of cryoablation for AVNRT with the 4-mm and 6-mm tip cryoablation catheters in a young population and to elicit predictors of arrhythmia recurrence. Methods: We retrospectively reviewed all patients who underwent cryoablation for AVNRT at the UCSF/Stanford Pediatric Arrhythmia Center from January 2004 to February 2007. Results: One hundred fifty-four patients (age 13.7 years (3.2,24.4)) underwent cryoablation for AVNRT of which 144 patients had inducible AVNRT (123 sustained and 21 nonsustained) and 10 had presumed AVNRT. Initial success was achieved in 95% (146/154), with no difference between the 4-mm (93%) and 6-mm (98%) cryoablation catheter tips (P = 0.15). There was no permanent atrioventricular (AV) block. Transient third-degree AV block occurred in nine patients (6%), with no difference between the 4-mm (4%) and 6-mm (9%) tip (P = 0.13). AVNRT recurrence was documented in 14% in a median time of 2.5 months (0.25,20). Recurrences were lower with the 6-mm (9%) versus the 4-mm (18%) tip, but this did not reach statistical significance (P = 0.16). With univariate analysis, a longer fluoroscopy time was the only significant factor associated with recurrence. Multivariate analysis failed to identify any significant predictor of AVNRT recurrence. Conclusion: Outcomes of cryoablation for AVNRT continue to be good without the complication of AV block. We could not identify any specific parameter associated with AVNRT recurrence. Further improvements in cryoablation technique will be necessary to reduce recurrences. [source] Routine bacterial culture from epidural catheter tipsANAESTHESIA, Issue 2 2007S. Sagadai No abstract is available for this article. [source] Clinical implication of routine bacterial culture from epidural catheter tips in postoperative cancer patients: a prospective studyANAESTHESIA, Issue 9 2006S. Mishra Summary We conducted a prospective study to determine the epidural tip culture pattern and its clinical implication in postoperative cancer patients. All patients scheduled to undergo various cancer surgeries requiring epidural analgesia were included. Epidural catheter tips were sent for culture on removal. Of the 466 epidural catheter tips sent for culture, 27 showed a positive culture (5.7%). The commonest organism identified was Staphylococcus aureus. There were no signs of local or epidural space infection in any of the patients. The rates of epidural catheter tip cultures in cancer patients are comparable to those in the general patients and the presence of a positive tip culture is not a predictor of epidural space infection. Hence, we recommend that even in cancer patients, routine culture of epidural catheters is not advisable, provided strict asepsis is maintained at the time of insertion, and patients are constantly monitored for early signs of epidural infection. [source] Staphylococcus aureus as source of catheter-related bloodstream infection evaluated by PFGE and rep-PCR typing in a Brazilian hospital,APMIS, Issue 11 2008GERALDO SADOYAMA Staphylococci are a common cause of catheter-related bloodstream infection (CR-BSI), and epidemiological typing is an important tool for effective infection control. This study evaluated by PFGE and rep-PCR whether Staphylococcus aureus strains isolated from skin and catheter tips were related to specimens isolated from blood. A prospective observational study, carried out in a clinical surgical ward at a Brazilian hospital between September 2000 and November 2002, investigated non-tunneled central venous catheters from 179 patients. S. aureus isolates were mainly obtained from blood (41.4%), while coagulase-negative staphylococci strains were more often isolated from the skin at the catheter insertion site (49.7%) and from the catheter tip (57.5%). Among the 21 strains isolated from 9 patients at 2 or 3 sites simultaneously, 9 were methicillin-resistant S. aureus (MRSA) and 12 were methicillin-susceptible S. aureus (MSSA). Seven patients harbored the same S. aureus strain isolated from the skin, blood and/or catheter tip cultures. MRSA isolates belonged to one PFGE pattern (type A- subtypes A1, A2 and A3), and to two rep-PCR patterns (a and b). MSSA isolates were distinguished in five PFGE (B to F) and in three rep-PCR (c, d and e) patterns. Both PFGE and rep-PCR methods indicated that the skin at the catheter insertion site was the origin of CR-BSI caused by S. aureus. [source] Numerical Simulation of Thrombus Aspiration in Two Realistic Models of Catheter TipsARTIFICIAL ORGANS, Issue 4 2010Giancarlo Pennati Abstract Thrombus aspiration catheters are devices used to remove a blood clot from a vessel, usually prior to angioplasty or stent implantation. However, in vitro results showed that the use of different commercial devices could produce very different thrombus removals, suggesting a primary dependence on the distal tip configuration of the catheter. A computational methodology based on realistic catheter tip modeling was developed to investigate the factors affecting the thrombus suction. Two different designs were considered, either with a single central lumen or a combination of central and side holes. First, steady-state aspiration of distilled water from a reservoir was simulated and compared with experimental tests. Subsequently, the aspiration of a totally occlusive thrombus, modeled as a high viscous fluid, was simulated solving a complex two-phase (blood and thrombus) problem. In particular, the benefit of additional openings was investigated. Good matching between the steady-state experimental and numerically simulated hydraulic behaviors allowed a validation of the numerical models. Numerical results of thrombus aspiration showed that the catheter with central and side holes had a worse performance if compared with the single central lumen catheter. Indeed, the inlets in contact with both blood and thrombus preferentially aspirate blood due to its much lower viscosity. This effect hindered the aspiration of thrombus. The amount of aspirated thrombus highly depends on the complex, two-phase fluid dynamics occurring across the catheter tips. Results suggested that location of additional holes is crucial in the catheter aspiration performance. [source] A bench study of ventilation via two self-assembled jet devices and the Oxygen Flow Modulator in simulated upper airway obstructionANAESTHESIA, Issue 12 2009A. E. W. Hamaekers Summary In managing an obstructed upper airway, an emergency transtracheal ventilation device needs to function as a bidirectional airway, allowing both insufflation of oxygen and egress of gas. The aim of the present study was to determine the capability of two self-assembled, three-way stopcock based jet devices and the Oxygen Flow Modulator to function as a bidirectional airway in conjunction with a small lumen catheter. For each device the effective pressures at the catheter's tip during the expiratory phase and the achievable minute volumes were determined in a laboratory set-up. Using the three-way stopcock based jet devices, changing the connection position of the transtracheal catheter from the in-line port to the side port of the three-way stopcock resulted in a decrease of expiratory pressure at the catheter's tip from a dangerous mean (SD) of 71.1 (0.08) cmH2O to ,14.71 (0.05) cmH2O. Yet this negative expiratory pressure did not facilitate the egress of gas. All devices tested impeded the expiratory outflow and hence decreased the achievable minute volume. This decrease in minute volume was smallest with the Oxygen Flow Modulator. [source] | ||||||||||