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M Rocco

Publications and source records attributed to M Rocco.

At least 19 recordsLinked to original sources
PubMed2006

Ultrasonographic analysis in vitro of parietal thickness of lower limb varicose veins.

PURPOSE: The aim of this study was to evaluate the ability of ultrasound (US) to measure the parietal thickness of varicose veins. MATERIALS AND METHODS: In a blind in vitro analysis, 28 great saphenous veins, obtained after stripping surgery from 28 patients with chronic venous insufficiency, were examined with a digital US scanner ATL-HDI5000, linear 5-1 to 2-MHz broadband probe, compound imaging technique and analogic-digital zooming. We obtained one to three progressive measurements for each vein wall (total 67 parietal thicknesses). The samples, fixed in formalin, were sent to the pathology laboratory: sections were obtained at the same level of the sonographic planes, and images were obtained by digital camera mounted on an optical microscope. Measurements obtained at histology were considered as the gold standard. K-statistic was applied to compare sonographic and histologic measurements. RESULTS: Considering only the hypoechoic wall portion, 29/29 (100%) diagnoses of hypotrophy (K=0.91), 19/22 (86%) diagnoses of normotrophy (K=0,47) and 12/16 (75%) diagnoses of hypertrophy (K=0.7) were obtained by sonography. CONCLUSIONS: In our preliminary experience, the in vitro study of varicose veins allows precise, at least morphological, detection of hypotrophic walls. If these preliminary data are confirmed in vivo, sonography could be used to discriminate patients eligible for conservative treatment instead of surgery.

Adult↗
PubMed2005

Antimicrobial susceptibility, biochemical and genetic profiles of Staphylococcus haemolyticus strains isolated from the bloodstream of patients hospitalized in critical care units.

Staphylococcus haemolyticus strains (n=20), responsible of blood stream infections, were consecutively isolated from patients hospitalized in two different wards at high risk of infection. Strains displayed high rate of resistance to oxacillin (90%). All strains but two with decreased susceptibility (MIC = 4 microg/mL), were sensitive to vancomycin. Ten strains were resistant to teicoplanin. Among the strains susceptible to glycopeptides, three displayed heteroresistance to vancomycin and seven to teicoplanin, when tested by Etest technique with 2 x McFarland inoculum. Biochemical reactions allowed to assign strains to eight biotypes, with 11 strains clustering under two main biotype A and biotype B. Pulsed-field-gel-electrophoresis (PFGE) identified 11 different PFGE-types. Seven strains grouping under the major PFGE-type 1 and three strains clustering in PFGE-type 2, closely correlated to biotype A and biotype B respectively. Seven teicoplanin-resistant isolates clustered in the PFGE-type 1, two in the PFGE-type 2 and one in PFGE-type 5. Therefore, teicoplanin-resistant strains were biochemically and genetically related and clonally distributed, despite different clones of S. haemolyticus circulated in the units during the study period.

Adult↗
PubMed2004

Psychiatric comorbidities in patients with Parkinson disease and psychosis.

OBJECTIVE: To determine the prevalence and impact of comorbid psychiatric disturbances in Parkinson disease (PD) patients with psychosis. METHODS: Subject data were derived from a research database of 116 PD patients participating in standardized motor, cognitive, psychiatric, and caregiver assessments. RESULTS: There were 25 patients (22%) with psychosis manifest as hallucinations (n = 9), delusions (n = 1), or hallucinations and delusions (n = 15) and 25 patients (22%) who had no current or past psychiatric comorbidities (PDN). In the psychotic group, 44% had psychosis only (PSY), and 56% had psychosis plus at least one other comorbid psychiatric disturbance (PSY+), including depressive disorders (71%), anxiety disorders (21%), apathetic syndromes (14%), and delirium (14%). There were no differences in age, sex, education, or age onset or duration of PD among the PSY, PSY+, and PDN groups. Both psychotic groups had greater motor, functional, and frontal cognitive deficits and increased caregiver burden scores relative to PDN. PSY+ showed greater global and selective cognitive deficits compared to PDN. Psychosis was a primary predictor of caregiver burden, whereas depressive symptoms indirectly enhanced motor impairments. CONCLUSIONS: Nonpsychotic psychiatric disturbances, especially affective disturbances, are common comorbidities in PD patients with psychosis and warrant clinical attention to reduce morbidity and caregiver distress.

Activities of Daily Living↗
PubMed2002

Noninvasive vs. conventional mechanical ventilation in patients with chronic obstructive pulmonary disease after failure of medical treatment in the ward: a randomized trial.

OBJECTIVE: We conducted a randomized prospective study comparing noninvasive positive pressure ventilation (NPPV) with conventional mechanical ventilation via endotracheal intubation (ETI) in a group of patients with chronic obstructive pulmonary disease who failed standard medical treatment in the emergency ward after initial improvement and met predetermined criteria for ventilatory support. DESIGN AND SETTING: Prospective randomized study in a university hospital 13-bed general ICU. PATIENTS: Forty-nine patients were randomly assigned to receive NPPV (n=23) or conventional ventilation (n=26). RESULTS: both NPPV and conventional ventilation significantly improved gas exchanges. The two groups had similar length of ICU stay, number of days on mechanical ventilation, overall complications, ICU mortality, and hospital mortality. In the NPPV group 11 (48%) patients avoided intubation, survived, and had a shorter duration of ICU stay than intubated patients. One year following hospital discharge the NPPV group had fewer patients readmitted to the hospital (65% vs. 100%) or requiring de novo permanent oxygen supplementation (0% vs. 36%). CONCLUSIONS: The use of NPPV in patients with chronic obstructive pulmonary disease and acute respiratory failure requiring ventilatory support after failure of medical treatment avoided ETI in 48% of the patients, had the same ICU mortality as conventional treatment and, at 1-year follow-up was associated with fewer patients readmitted to the hospital or requiring for long-term oxygen supplementation. An editorial regarding this article can be found in the same issue (http://dx.doi.org/10.1007/s00134-002-1503-3).

Aged↗
PubMed2002

Mammary implants: laboratory simulation of recreational diving conditions.

To ascertain whether mammary implants are prone to changes in conformation or structure if they are submitted to recreational dives, eight mammary implants were submitted to 40 simulated dives to imitate an average recreational diving schedule. Matching implants were used as a control group. Photographs were taken before and after completion of the protocol. All implants were observed for changes in volume and checked for integrity. Variations in density were evaluated using a Tc scan. No changes in volume occurred after each dive. None of the implants showed ruptures, and Tc scanning failed to reveal any differences in density between tested and control implants. Cohesive-gel implants submitted to the simulated dives showed some morphological alterations. This study indicates that the mammary implants tested could be implanted in a sports diver, but raises concern about whether the increased exposure to stress could negatively affect their durability.

Breast Implants↗
PubMed2001

Leptin presence in plasma, liver and fat bodies in the lizard Podarcis sicula: fluctuations throughout the reproductive cycle.

Leptin is a 16 kDa peptide produced by adipocytes in response to increasing fat stores and signals to the brain to stop eating and increase energy expenditure. Recent studies point out that the role of leptin is much broader and includes the regulation of reproduction. The lizard, Podarcis sicula, is an oviparous species characterized, at this latitude, by a seasonal reproductive cycle. Since in Podarcis sicula the recovery of the gonadal function coincides with the recovery of metabolic activity, we have hypothesized that leptin might be involved in the regulation of the reproductive function in this species. We have identified an immunoreactive band in the plasma of the female of Podarcis sicula, which comigrated with recombinant mouse leptin and cross reacted with polyclonal antibodies against mouse leptin. A RIA method developed by Linco (St. Louis, MO) was utilized to measure leptin concentration in plasma, liver and fat bodies of Podarcis sicula throughout the reproductive cycle. The antibody used in this kit (Linco's Multi-Species Leptin Radioimmunoassay kit) was produced in the guinea pig against human leptin but displays crossreactivity to leptin molecules of many species. The level of leptin in the plasma of Podarcis sicula was in the same range as that of mammals. Leptin levels in plasma, liver and fat bodies fluctuated during the reproductive cycle, in a way consistent with its possible role in reproduction.

Animals↗
PubMed2001

Growth kinetics and structure of fibrin gels.

The structure and kinetics of fibrin gels grown from fibrinogen solutions under quasiphysiological conditions, but in absence of Ca++, were investigated by means of elastic light scattering. By combining classical light scattering and low-angle elastic light scattering, an overall wave-vector range of about three decades was spanned, from q approximately 3 x 10(2) to q approximately 3 x 10(5) cm(-1). The scattered intensity distribution of the gels was measured in absolute units and fitted to a single function, which was able to reproduce accurately the data over the entire wave-vector range. From the fitting, it was possible to estimate the average diameter d of the fibrin fibers, the average crossover length xi of the gel, and establish the fractal nature of the gel structure, with a measure of its fractal dimension D(m). The measure of the intensity in absolute units also allowed the estimate of the density rho of the fibrin fibers and provided an independent measure of their size. The kinetics of formation of the gel was described in terms of a simple growth model: the scaffold of the network is formed very early in the course of the gelation process, at a "networking time," t(n), which is much smaller than the time required to form the final gel. At times t>t(n), the gel structure remains substantially unchanged and the successive growth consists only in a thickening of the gel fibers. Gels prepared under the same physical-chemical conditions, but at different fibrinogen concentrations, exhibited rather similar structures and kinetics, showing that the modalities of the gelation process are mainly governed by the solution conditions, and only secondarily by the fibrinogen concentration. For gels at fibrinogen concentration of approximately 0.24 mg/ml, the gel parameters were d approximately 130 nm, xi approximately 27 microm, D(m) approximately 1.3, and rho approximately 0.4 g/cm(3). Our d and rho values are in very good agreement with electron microscopy- and turbidity-derived literature data, respectively, while xi seems to be related to the mesh size of the initial scaffold formed at t(n), rather than to the mesh size of the final aged gel.

Fibrin↗
PubMed2001

Non-invasive pressure support ventilation in patients with acute respiratory failure after bilateral lung transplantation.

OBJECTIVE: To evaluate non-invasive ventilation (NIV) prospectively in a group of patients developing acute respiratory failure (ARF) after bilateral lung transplantation (BLT). SETTING: General intensive care unit (ICU) of Rome "La Sapienza" University. PATIENTS: Twenty-one patients (18 with cystic fibrosis) undergoing BLT. RESULTS: All consecutive patients developing ARF (according to predefined criteria) and requiring ventilatory support, received non-invasive pressure support ventilation through a face-mask (PEEP 5 cmH2O, PSV 14+/-2 cmH2O) for a mean period of 5+/-4 days. Eighteen out of 21 patients avoided intubation and were discharged from the ICU; 3 patients required intubation: 1 of them survived while 2 developed septic shock and died. CONCLUSIONS: NIV administration was well tolerated and avoided intubation in the large majority of patients (86%); in NIV responders the rate of complications was low and ICU mortality nil. NIV should be considered as an interesting alternative to conventional ventilation in patients who require ventilatory support after BLT.

Acute Disease↗
PubMed2001

The role of the dietitian in a multicenter clinical trial of dialysis therapy: the Hemodialysis (HEMO) Study.

The Hemodialysis (HEMO) Study is a randomized multicenter prospective clinical trial, supported by the National Institute of Diabetes, Digestive, and Kidney Diseases of the National Institutes of Health. The trial is designed to assess the effects of a standard versus higher dialysis dose and low versus high dialysis membrane flux on morbidity and mortality of chronic hemodialysis patients. The role of the dietitian in the HEMO Study is to support and maintain the nutritional status of randomized participants. To ensure participant safety, nutritional status is closely monitored by a variety of biochemical and participant-reported parameters. Serum albumin and equilibrated normalized protein catabolic rates are obtained monthly. Appetite assessment and dietary energy and protein intakes using a 2-day diet diary assisted recall are ascertained at baseline and on a yearly basis. Consumption of vitamins, minerals, and nutritional supplements, including oral enterals, tube feedings, and parenteral nutrition, is obtained at least once a year. In addition, anthropometry is performed at baseline and on a yearly basis. Prespecified changes in serum albumin level or body weight trigger action by the dietitian to prevent protein calorie malnutrition. The HEMO Study dietitians play a vital role in carrying out the nutrition program for the trial. The HEMO Study should provide important information about the natural history of the nutritional status of chronic hemodialysis patients and the impact of dialysis dose and dialysis membrane flux on these parameters.

Anthropometry↗
PubMed2001

Binding of a fibrinogen mimetic stabilizes integrin alphaIIbbeta3's open conformation.

The platelet integrin alphaIIbbeta3 is representative of a class of heterodimeric receptors that upon activation bind extracellular macromolecular ligands and form signaling clusters. This study examined how occupancy of alphaIIbbeta3's fibrinogen binding site affected the receptor's solution structure and stability. Eptifibatide, an integrin antagonist developed to treat cardiovascular disease, served as a high-affinity, monovalent model ligand with fibrinogen-like selectivity for alphaIIbbeta3. Eptifibatide binding promptly and reversibly perturbed the conformation of the alphaIIbbeta3 complex. Ligand-specific decreases in its diffusion and sedimentation coefficient were observed at near-stoichiometric eptifibatide concentrations, in contrast to the receptor-perturbing effects of RGD ligands that we previously observed only at a 70-fold molar excess. Eptifibatide promoted alphaIIbbeta3 dimerization 10-fold more effectively than less selective RGD ligands, as determined by sedimentation equilibrium. Eptifibatide-bound integrin receptors displayed an ectodomain separation and enhanced assembly of dimers and larger oligomers linked through their stalk regions, as seen by transmission electron microscopy. Ligation with eptifibatide protected alphaIIbbeta3 from SDS-induced subunit dissociation, an effect on electrophoretic mobility not seen with RGD ligands. Despite its distinct cleft, the open conformer resisted guanidine unfolding as effectively as the ligand-free integrin. Thus, we provide the first demonstration that binding a monovalent ligand to alphaIIbbeta3's extracellular fibrinogen-recognition site stabilizes the receptor's open conformation and enhances self-association through its distant transmembrane and/or cytoplasmic domains. By showing how eptifibatide and RGD peptides, ligands with distinct binding sites, each affects alphaIIbbeta3's conformation, our findings provide new mechanistic insights into ligand-linked integrin activation, clustering and signaling.

Binding Sites↗
PubMed2001

Early events in the polymerization of fibrin.

The early events in the thrombin-induced formation of fibrin have been studied by the use of stopped-flow multiangle laser light scattering (SF-MALLS). This technological advancement has allowed the recovering, as a function of time with a resolution of about 0.5 sec, of the mean square radius of gyration (Rg2)z and of the molecular weight Mw, and to place an upper bound to the values of the mass/unit length ML. The ionic strength, pH and salt type conditions investigated were all close to physiological, starting with a 50 mM Tris, 104 mM NaCl, pH 7.4 buffer (TBS), to which either 1 mM EDTA-Na2 or 2.5 mM CaCl2 were also added. Fibrinogen was 0.2-0.3 mg/ml and rate-limiting concentrations of thrombin were used (0.05-0.25 NIH units/mg fibrinogen). By plotting (Rg2)z and ML versus Mw on log-log scales, runs proceeding at different velocities and under different solvent conditions could be compared and confronted with model curves. It was found that: (1) within this thrombin range, the mechanism of association does not depend on its concentration, nor on the buffers employed; (2) the (Rg2)z versus Mw curves could all be reasonably fitted with a bifunctional polycondensation scheme involving semiflexible worm-like, double-stranded, half-staggered polymers with persistence length between 200-600 nm, provided that a ratio Q = 16 between the rate of release of the two fibrinopeptides A was employed; (3) the ML versus Mw data seemed more compatible with lower Q values (4 < Q < 8), but their uncertainty prevented a better assessment of this issue; the formation of fibrinogen-fibrin monomer complexes may also play a role in the polymer distributions; (4) in the very early stages (e.g., when Mw < 7 x 10(5)), the (Rg2)z versus Mw data were fitted well only in TBS and at the lowest thrombin concentration, suggesting that a transient, either sequential or concurrent fast second mechanism, involving longer and thinner polymers, may be at work.

Biopolymers↗
PubMed2001

Lipid peroxidation, circulating cytokine and endothelin 1 levels in healthy volunteers undergoing hyperbaric oxygenation.

BACKGROUND: The aim of the present study was to evaluate the effects of hyperbaric oxygenation on lipid peroxidation, on the release of circulating cytokines (TNFa, IL6, IL1b) and endothelin-1 (ET1). METHODS EXPERIMENTAL DESIGN: single arm, prospective study. SETTING: ICU hyperbaric division of a University Hospital. PATIENTS: fifteen healthy volunteers (10 male and 5 female, mean age 32+/-7 years) studied during hyperbaric oxygenation divided at random into two groups: group A (7 subjects) and group B (8 subjects). INTERVENTIONS: Both groups were consecutively pressurized at 2 atmospheres (2 atm abs) and 2.8 atm abs, with a constant descending rate of 1 m/min; in accordance with the experimental design, group A breathed pure oxygen continuously through facial masks and group B breathed chamber air during pressurization. MEASURES: Twenty millilitres of blood were drawn from all individuals at the following times: 1) basal, before HBO; 2) after 10 min at 2 atm abs; 3) after 10 min at 2.8 atm abs; 4) 30 min after the end of HBO. In all collected samples thiobarbituric reacting substances were evaluated, using the spectrophotometric technique, IL1 TNF and IL6 serum levels by ELISA and endothelin 1 plasma levels by radioimmunoassay. RESULTS: In both groups, TBARS levels showed a twofold increase (p<0.05) in relation to the baseline, during and after hyperbaric oxygenation. Serum IL6 and IL1b values did not significantly change over the study in any of the volunteers. TNFa amounts significantly increased (p<0.05) during HBO, at 2 atm abs and 2.8 atm abs in both groups, with almost twofold increments. ET1 plasma values increased (p<0.05) in all volunteers during and after HBO: at 2 atm abs (range 7 to 24 pg/ml), 2.8 atm abs (range 7 to 19 pg/ml) and 30 min after (range 8 to 17 pg/ml) in relation to baseline (range 4 to 12 pg/ml). All the studied compounds had a similar trend in the two groups. CONCLUSIONS: Hyperbaric oxygenation in healthy volunteers can induce not only lipid peroxidation, but also liberation of compounds such as TNFa and endothelins, no matter whether pure oxygen is breathed or not. These results suggest that the phenomenon behind this release might be leukocyte activation as induced by HBO. The possible role of ET1 in determining vasoconstriction occurring during HBO is also suggested.

Adult↗
PubMed2000

Noninvasive ventilation for treatment of acute respiratory failure in patients undergoing solid organ transplantation: a randomized trial.

CONTEXT: Noninvasive ventilation (NIV) has been associated with lower rates of endotracheal intubation in populations of patients with acute respiratory failure. OBJECTIVE: To compare NIV with standard treatment using supplemental oxygen administration to avoid endotracheal intubation in recipients of solid organ transplantation with acute hypoxemic respiratory failure. DESIGN AND SETTING: Prospective randomized study conducted at a 14-bed, general intensive care unit of a university hospital. PATIENTS: Of 238 patients who underwent solid organ transplantation from December 1995 to October 1997, 51 were treated for acute respiratory failure. Of these, 40 were eligible and 20 were randomized to each group. INTERVENTION: Noninvasive ventilation vs standard treatment with supplemental oxygen administration. MAIN OUTCOME MEASURES: The need for endotracheal intubation and mechanical ventilation at any time during the study, complications not present on admission, duration of ventilatory assistance, length of hospital stay, and intensive care unit mortality. RESULTS: The 2 groups were similar at study entry. Within the first hour of treatment, 14 patients (70%) in the NIV group, and 5 patients (25%) in the standard treatment group improved their ratio of the PaO2 to the fraction of inspired oxygen (FIO2). Over time, a sustained improvement in PaO2 to FIO2 was noted in 12 patients (60%) in the NIV group, and in 5 patients (25%) randomized to standard treatment (P = .03). The use of NIV was associated with a significant reduction in the rate of endotracheal intubation (20% vs 70%; P = .002), rate of fatal complications (20% vs 50%; P = .05), length of stay in the intensive care unit by survivors (mean [SD] days, 5.5 [3] vs 9 [4]; P = .03), and intensive care unit mortality (20% vs 50%; P = .05). Hospital mortality did not differ. CONCLUSIONS: These results indicate that transplantation programs should consider NIV in the treatment of selected recipients of transplantation with acute respiratory failure.

Female↗
PubMed2000

Polymerization of rod-like macromolecular monomers studied by stopped-flow, multiangle light scattering: set-up, data processing, and application to fibrin formation.

Many biological supramolecular structures are formed by polymerization of macromolecular monomers. Light scattering techniques can provide structural information from such systems, if suitable procedures are used to collect the data and then to extract the relevant parameters. We present an experimental set-up in which a commercial multiangle laser light scattering photometer is linked to a stopped-flow mixer, allowing, in principle, the time-resolved extrapolation of the weight-average molecular weight M(w) and of the z-average square radius of gyration (z) of the polymers from Zimm-like plots. However, if elongated structures are formed as the polymerization proceeds, curved plots rapidly arise, from which M(w) and (z) cannot be recovered by linear fitting. To verify the correctness of a polynomial fitting procedure, polydisperse collections of rod-like or worm-like particles of different lengths, generated at various stages during bifunctional polycondensations of rod-like macromolecular monomers, were considered. Then, the angular dependence of their time-averaged scattered intensity was calculated in the Rayleigh-Gans-Debye approximation, with random and systematic noise also added to the data. For relatively narrow size distributions, a third-degree polynomial fitting gave satisfactory results across a broad range of conversion degrees, yielding M(w) and (z) values within 2% and no greater than 10-20%, respectively, of the calculated values. When more broad size distributions were analyzed, the procedure still performed well for semiflexible polymers, but started to seriously underestimate both M(w) and (z) when rigid rod-like particles were analyzed, even at relatively low conversion degrees. The data were also analyzed in the framework of the Casassa approximation, from which the mass per unit length of the polymers can be derived. These procedures were applied to a set of data taken on the early stages of the thrombin-catalyzed polymerization of fibrinogen, a rod-like macromolecule approximately 50 nm long. The polymers, grown in the absence of Ca(2+) by rate-limiting amounts of thrombin, appeared to be characterized by a much broader size distribution than the one expected for a classical Flory bifunctional polycondensation, and they seem to behave as relatively flexible worm-like double-stranded chains. Evidence for the formation of fibrinogen-fibrin monomer complexes is also inferred from the time dependence of the mass/length ratio. However, our data are also compatible with the presence of limited amounts of single-stranded structures in the very early stages, either as a secondary, less populated pathway, or as transient intermediates to the classical double-stranded fibrils.

Chromatography, High Pressure Liquid↗
PubMed2000

Peritoneal dialysis adequacy and risk of death.

BACKGROUND: The purpose of this study was to evaluate the relationship between dialysis dose, patient characteristics, and medical comorbidities on mortality in chronic peritoneal dialysis patients. METHODS: This work comprised a study cohort of 1446 patients obtained from a random sample of chronic peritoneal dialysis patients from each dialysis center in three southeastern states. Data collected on a standardized form were used to calculate weekly Kt/V urea and creatinine clearance. Data were linked to Network files containing data on patient demographic and medical comorbidities. RESULTS: Both weekly Kt/V urea and creatinine clearance were measured at least once in only 60.5% of continuous ambulatory peritoneal dialysis (CAPD) patients and 63.7% of cycler patients. Among the 873 patients who had at least one calculable adequacy measure, the mean (+/-SD) weekly Kt/V urea was 2.13 +/- 0.55, and the normalized mean weekly creatinine clearance was 62.9 +/- 20.4 L/week/m2. During the seven month period of follow-up, there were 140 deaths. In separate logistic regression models that included all of the studied risk factors, using separate variables for the urinary and peritoneal components of dialysis adequacy, each 10 L/week/1.73 m2 increase in the urinary component of weekly creatinine clearance was associated with a 40% decreased risk of death, and each 0.1 unit increase in the urinary component of weekly Kt/V urea was associated with a 12% decreased risk of death. In contrast, the dialysate components of neither weekly creatinine clearance nor weekly Kt/V urea were predictive of death. Other factors that were associated with an increased risk of death included increasing age, diabetes mellitus as the cause of end-stage renal disease (ESRD), and a history of myocardial infarction. CONCLUSIONS: Residual renal function, as expressed by weekly creatinine clearance or Kt/V urea, is an important predictor of death in chronic peritoneal dialysis patients. The nonsignificant findings regarding peritoneal clearances and mortality may possibly be secondary to the narrow range of peritoneal clearances in this study cohort.

Adolescent↗
PubMed2000

Efficacy of tissue plasminogen activator administration on patency of hemodialysis access catheters.

Patients with end-stage renal disease use hemodialysis catheters for either temporary or permanent blood access. Recurrent thrombosis and fibrin sheath formation are common causes of poor or inadequate blood flow rates that require intervention. We studied the effect of tissue plasminogen activator (tPA) in reestablishing adequate blood flow rates through nonfunctional vascular catheters in 22 consecutive chronic hemodialysis patients. From January 1, 1999, to May 20, 1999, there were 56 instances in which tPA was used in an attempt to improve blood flow rates. In all instances, 2 mg of tPA was infused into each port of a dual-lumen internal jugular catheter. Dwell time ranged between 2 and 96 hours (median, 24 hours), and patient follow-up ranged between 47 and 140 days (median, 133.5 days). tPA was effective in establishing adequate blood flow rates (>/=200 mL/min) during the next dialysis session in 49 of 56 cases (87.5%). Seven additional interventions were required because of early or late tPA failure (one fibrin sheath stripping, one catheter replacement for kinking, one catheter replacement for central venous stenosis, and four catheter replacements for persistently poor blood flow rates), and eight catheters were replaced for infection. Thus, further interventions to achieve adequate blood flow rates were required in 12.5% of the cases because of early or late tPA failure. tPA appears to be as effective as urokinase for reestablishing adequate blood flow rates through hemodialysis catheters that are thrombosed or have low blood flow rates.

Adult↗