Occluded Tunneled Venous Catheter in Hemodialysis Patients: Risk Factors and Efficacy of Alteplase

Thrombosis of tunneled central venous catheters (CVC) in hemodialysis (HD) patients is common and it can lead to the elimination of vascular sites. This study aimed to evaluate the incidence of thrombotic obstruction of tunneled CVC in HD patients and the efficacy of occlusion treatment with alteplase use, and identify factors associated with thrombotic occlusion. It was a prospective cohort study performed in two centers which evaluated the diagnosis and treatment of thrombotic occlusion of CVC in HD patients for 24 consecutive months. The catheter occlusion was defined as the difficulty infusing or withdrawing fluid from their paths. Alteplase dose was infused to fill the lumen of the occluded catheter and remained for 50 min. As there was no obstruction of the catheter, the procedure was repeated. Three hundred and thirty-nine CVC in 247 patients were evaluated and followed, totalling 67 244 CVC-days. One hundred fifty-seven patients had only one CVC, 88 patients had two CVC during the study, and two patients had three CVC. The median age was 58 (47–66) years, patients were predominantly men (54%), with diabetic nephropathy as the main cause of chronic kidney disease (44%), the internal jugular vein as the main site of implantation (82%), and duration of dialysis before CVC implantation of 119 (41.5 to 585.5) days. Eight hundred and fifteen occlusion episodes were diagnosed (12 episodes/1000 CVC-days), with primary success with alteplase in 596 episodes (77%) and secondary in 81 cases (10%). In 99 episodes (13%), success was not achieved after the second dose of alteplase. Two hundred and thirty CVC were removed during the study and the removal causes were arteriovenous fistula use in 88 patients (38.3%), infectious and mechanical complications in 89 (38.7%) and 21 (9.1%), respectively, and others (transplantation, transfer, or death) in 32 patients (13.9%). Adverse effects were also not observed. In the multivariate analysis, we identified the greatest number of days with CVC (OR = 1.02, CI = 1.01–1.04, P = 0.004), the presence of diabetes (OR = 1.560, CI = 1.351–1.894, P = 0.015), and exit site infection (ESI) (OR = 1.567 CI = 1347–1926, P = 0.023) as factors associated with obstruction. Thrombotic occlusion showed frequent mechanical complication in CVC of HD patients. We observed 12 episodes of obstruction per 1000 CVC-days, with a high success rate after alteplase use (87%). In the multivariate analysis, the time with CVC, the presence of diabetes, and ESI were identified as variables associated with thrombotic obstruction.

Effects of arterial oxygen tension and cardiac output on venous saturation: a mathematical modeling approach

OBJECTIVES: Hemodynamic support is aimed at providing adequate O-2 delivery to the tissues; most interventions target O-2 delivery increase. Mixed venous O-2 saturation is a frequently used parameter to evaluate the adequacy of O-2 delivery. METHODS: We describe a mathematical model to compare the effects of increasing O-2 delivery on venous oxygen saturation through increases in the inspired O-2 fraction versus increases in cardiac output. The model was created based on the lungs, which were divided into shunted and non-shunted areas, and on seven peripheral compartments, each with normal values of perfusion, optimal oxygen consumption, and critical O-2 extraction rate. O-2 delivery was increased by changing the inspired fraction of oxygen from 0.21 to 1.0 in steps of 0.1 under conditions of low (2.0 L.min(-1)) or normal (6.5 L.min(-1)) cardiac output. The same O-2 delivery values were also obtained by maintaining a fixed O-2 inspired fraction value of 0.21 while changing cardiac output. RESULTS: Venous oxygen saturation was higher when produced through increases in inspired O-2 fraction versus increases in cardiac output, even at the same O-2 delivery and consumption values. Specifically, at high inspired O-2 fractions, the measured O-2 saturation values failed to detect conditions of low oxygen supply. CONCLUSIONS: The mode of O-2 delivery optimization, specifically increases in the fraction of inspired oxygen versus increases in cardiac output, can compromise the capability of the "venous O-2 saturation" parameter to measure the adequacy of oxygen supply. Consequently, venous saturation at high inspired O-2 fractions should be interpreted with caution.

Centrilobular necrosis as a manifestation of venous outflow block in pediatric malnourished liver transplant recipients - case reports

CLN is a frequent histological finding in biopsies after pediatric: LT, and its pathogenesis has not yet been fully clarified and has different causes. Among the vascular causes, VOB is sometimes difficult to diagnose, especially when technical variants such as split-liver, reduced-liver, or living-related LT are utilized. Three liver-transplanted malnourished children (ages 12, 20, and 28 months) developed altered LFTs and post-operative ascites with right pleural effusion (two cases) and jaundice (one case). Doppler ultrasound examinations were normal and liver biopsies showed CLN interpreted as severe ACR. There were no responses to the medical treatment. Additional investigation with CT angiography suggested obstructed hepatic vein drainage, which was confirmed by interventional radiology and angioplasty of the anastomosis between the hepatic vein and the inferior vena cava, with clinical and histological resolution. It is concluded that in malnourished children undergoing LT with technical variations, in which the occurrence of severe ACR is usually less common because of the severity of the patient condition, the finding of CLN should raise the possibility of VOB, so that excessive immunosuppression and its consequences can be avoided.

Trends in aortic aneurysm- and dissection-related mortality in the state of Sao Paulo, Brazil, 1985-2009: multiple-cause-of-death analysis

Background: Aortic aneurysm and dissection are important causes of death in older people. Ruptured aneurysms show catastrophic fatality rates reaching near 80%. Few population-based mortality studies have been published in the world and none in Brazil. The objective of the present study was to use multiple-cause-of-death methodology in the analysis of mortality trends related to aortic aneurysm and dissection in the state of Sao Paulo, between 1985 and 2009. Methods: We analyzed mortality data from the Sao Paulo State Data Analysis System, selecting all death certificates on which aortic aneurysm and dissection were listed as a cause-of-death. The variables sex, age, season of the year, and underlying, associated or total mentions of causes of death were studied using standardized mortality rates, proportions and historical trends. Statistical analyses were performed by chi-square goodness-of-fit and H Kruskal-Wallis tests, and variance analysis. The joinpoint regression model was used to evaluate changes in age-standardized rates trends. A p value less than 0.05 was regarded as significant. Results: Over a 25-year period, there were 42,615 deaths related to aortic aneurysm and dissection, of which 36,088 (84.7%) were identified as underlying cause and 6,527 (15.3%) as an associated cause-of-death. Dissection and ruptured aneurysms were considered as an underlying cause of death in 93% of the deaths. For the entire period, a significant increased trend of age-standardized death rates was observed in men and women, while certain non-significant decreases occurred from 1996/2004 until 2009. Abdominal aortic aneurysms and aortic dissections prevailed among men and aortic dissections and aortic aneurysms of unspecified site among women. In 1985 and 2009 death rates ratios of men to women were respectively 2.86 and 2.19, corresponding to a difference decrease between rates of 23.4%. For aortic dissection, ruptured and non-ruptured aneurysms, the overall mean ages at death were, respectively, 63.2, 68.4 and 71.6 years; while, as the underlying cause, the main associated causes of death were as follows: hemorrhages (in 43.8%/40.5%/13.9%); hypertensive diseases (in 49.2%/22.43%/24.5%) and atherosclerosis (in 14.8%/25.5%/15.3%); and, as associated causes, their principal overall underlying causes of death were diseases of the circulatory (55.7%), and respiratory (13.8%) systems and neoplasms (7.8%). A significant seasonal variation, with highest frequency in winter, occurred in deaths identified as underlying cause for aortic dissection, ruptured and non-ruptured aneurysms. Conclusions: This study introduces the methodology of multiple-causes-of-death to enhance epidemiologic knowledge of aortic aneurysm and dissection in Sao Paulo, Brazil. The results presented confer light to the importance of mortality statistics and the need for epidemiologic studies to understand unique trends in our own population.

Fetal venous Doppler in pregnancies with placental dysfunction and correlation with pH at birth

Objectives: To determine the correlation between ph at birth and venous Doppler parameters in pregnancies with placental dysfunction. Methods: This was a prospective cohort study of 58 pregnancies with the diagnosis of placental dysfunction between 26 and 34 weeks of gestation. Inclusion criteria were singleton pregnancies, abnormal umbilical artery (UA) Doppler, fetal growth restriction diagnosed by estimated fetal weight <10th centile for gestational age, intact membranes, and absence of fetal congenital abnormalities. The Doppler measurements were the following: UA pulsatility index (PI), ductus venosus (DV) pulsatility index for veins (PIV), intra-abdominal umbilical vein (UV) time-averaged maximum velocity (TAMxV) and blood flow and left portal vein (LPV) time-averaged maximum velocity (TAMxV) and blood flow. All Doppler parameters were transformed into z-scores (SD values from the mean) according to normative references. Results: The UA pH at birth showed a negative significant correlation with the DV-PIV (p = 0.004) and the DV-PIV z-score (p = 0.004), while LPV TAMxV (p = 0.004), LPV TAMxV z-score (p = 0.002), LPV blood flow (p = 0.01), LPV blood flow normalized (p = 0.04) and UV blood flow (p = 0.04) positively correlated with pH at birth. Multiple regression analysis was performed and the DV-PIV z-score was the variable that independently correlated with pH at birth (p = 0.002). Conclusions: the present results suggest that changes in fetal venous blood flow, mainly DV and LPV are useful in the management of cases with early onset placental insufficiency and that venous Doppler parameters correlate with pH at birth.

Lupus anticoagulant: a marker for stroke and venous thrombosis in primary Sjogren's syndrome

Antiphospholipid antibodies (aPL) and antiphospholipid syndrome (APS) have been described in primary Sjogren's syndrome (pSS) with controversial findings regarding aPL prevalence and their association with thrombotic events. We evaluated 100 consecutive pSS patients (American-European criteria) and 89 age-gender-ethnicity-matched healthy controls for IgG/IgM anticardiolipin (aCL), IgG/IgM anti-beta2-glycoprotein-I (a beta 2GPI), and lupus anticoagulant (LA) (positivity according to APS Sydney's criteria). Clinical analysis followed standardized interview and physical examination assessing thrombotic and nonthrombotic APS manifestations and thrombosis risk factors. aPLs were detected in 16 % patients and 5.6 % controls (p = 0.035). LA was the most common aPL in patients (9 %), followed by a beta 2GPI (5 %) and aCL (4 %). Thrombotic events occurred in five patients [stroke in two, myocardial infarction in one and deep-vein thrombosis (DVT) in four], but in none of controls (p = 0.061). Mean age at time of stroke was 35 years. Three patients with thrombotic events (including the two with stroke) had APS (Sydney's criteria) and were positive exclusively for LA. Comparison of patients with (n = 16) and without (n = 84) aPL revealed similar mean age, female predominance, and ethnicity (p > =0.387). Frequencies of livedo reticularis (25 vs. 4.8 %, p = 0.021), stroke (12.5 vs. 0 %, p = 0.024), and DVT (18.8 vs. 1.2 %, p = 0.013) were significantly higher in APL + patients. Conversely, frequencies of hypertension, dyslipidemia, diabetes, obesity, smoking, sedentarism, and hormonal contraception were similar in patients with or without aPL (p a parts per thousand yenaEuro parts per thousand 0.253). Our study identified LA as an important marker for APS in pSS, particularly for stroke in young patients, warranting routine evaluation of these antibodies and rigorous intervention in modifiable risk factors.

Effect of a video on developing skills in undergraduate nursing students for the management of totally implantable central venous access ports

Background: Handling Totally Implantable Access Ports (TIAP) is a nursing procedure that requires skill and knowledge to avoid adverse events. No studies addressing this procedure with undergraduate students were identified prior to this study. Communication technologies, such as videos, have been increasingly adopted in the teaching of nursing and have contributed to the acquisition of competencies for clinical performance. Objective: To evaluate the effect of a video on the puncture and heparinization of TIAP in the development of cognitive and technical competencies of undergraduate nursing students. Method: Quasi-experimental study with a pretest-posttest design. Results: 24 individuals participated in the study. Anxiety scores were kept at levels 1 and 2 in the pretest and posttest. In relation to cognitive knowledge concerning the procedure, the proportion of correct answers in the pretest was 0.14 (SD=0.12) and 0.90 in the posttest (SD=0.05). After watching the video, the average score obtained by the participants in the mock session was 27.20. Conclusion: The use of an educational video with a simulation of puncture and heparinization of TIAP proved to be a strategy that increased both cognitive and technical knowledge. This strategy is viable in the teaching-learning process and is useful as a support tool for professors and for the development of undergraduate nursing students. (C) 2011 Elsevier Ltd. All rights reserved.

Totally implantable venous catheters: insertion via internal jugular vein with pocket implantation in the arm is an alternative for diseased thoracic walls

Purpose: Insertion of totally implantable catheters via deep vessels that drain into the superior vena cava results in a lower incidence of venous thrombosis and infection as compared to catheters inserted into femoral and arm veins. Superior vena cava obstruction and inadequacy of the thoracic wall are conditions that prevent reservoir implantation in the chest wall. In this article, we describe a technical innovation that enables the pocket to be fixed in the arm while still allowing access to be achieved via the internal jugular vein. Method: The procedure reported maintains the use of the internal jugular vein for access even when the patient's chest is not suited for reservoir implantation, which is localized in the arm. Results: The procedure was successful and no complications occurred. The position of the catheter tip did not alter with arm movement. Conclusion: The implantation of a port reservoir in the arm following venous access via the internal jugular vein is both safe and convenient.

Influence of high-heeled shoes on venous function in young women

Background: Walking with high-heeled shoes is a common cause of venous complaints such as pain, fatigue, and heavy-feeling legs. The aim of the study was to clarify the influence of high-heeled shoes on the venous return and test the hypothesis that women wearing different styles of high-heeled shoes present an impaired venous return when compared with their values when they are barefoot. Methods: Thirty asymptomatic women (mean age, 26.4 years) wearing appropriately sized shoes were evaluated by air plethysmography (APG), a test that measures changes in air volume on a cuff placed on the calf, while they performed orthostatic flexion and extension foot movements and altered standing up and lying down. The test was repeated in four situations: barefoot (0 cm), medium heels (3.5 cm), stiletto high heels (7 cm), and platform high heels (7 cm). The APG values of venous filling index (VFI), ejection fraction (EF), and residual volume fraction (RVF) were divided into four groups according to heel height and compared by repeated-measures analysis of variance. Results: RVF was increased in the groups wearing high heels (stiletto and platform) compared with the barefoot group (P < .05). RVF was increased in the medium-heel group (3.5 cm) compared with the barefoot group (P < .05), and despite the lack of statistical significance, the medium-heel group showed lower values of RVF compared with the two high-heel groups. The EF parameter followed the opposite tendency, showing higher values for the barefoot group compared with the other three groups (P < .05). Values for VFI were similar in the three situations evaluated. Conclusions: High heels reduce muscle pump function, as demonstrated by reduced EF and increased RVF values. The continuous use of high heels tends to provoke venous hypertension in the lower limbs and may represent a causal factor of venous disease symptoms. (J Vasc Surg 2012;56:1039-44.)

Comparison of venous plasma glycemia and capillary glycemia for the screening of type 2 diabetes mellitus in the Japanese-Brazilian community of Mombuca (Guatapará-SP)

Abstract Background To identify the most appropriate cut-off points of fasting glycemia for the screening of diabetes mellitus type 2 (DM2) with the comparison of the properties of capillary glycemia (CG) and venous blood plasma glycemia (PG) in a population of Japanese origin from the community of Mombuca, Guatapará - SP, Brazil. Methods This was a population-based descriptive cross-sectional study conducted on a sample of 131 individuals of both genders aged 20 years or more (66.8% of the target population). CG was measured with a glucometer in a blood sample obtained from the fingertip and PG was determined by an enzymatic method (hexokinase) in venous blood plasma, after a 10-14 hour fast in both cases. Data were analyzed by the receiver operating characteristic (ROC) curve in order to identify the best cut-off point for fasting glycemia (CG and PG) for the diagnosis of DM, using the 2-hour plasma glycemia > 200 mg/dl as gold - standard. Results The ROC curve revealed that the best cut-off point for the screening of DM was 110 mg/dl for CG and 105 mg/dl for PG, values that would optimize the relation between individuals with positive and false-positive results. The area under the ROC curve was 0.814 for CG (p < 0.01) and 0.836 for PG (p < 0.01). Conclusions The cut-off points of 105 mg/dl(5.8 mmol/l) for PG and of 110 mg/dl(6.1 mmol/l) for CG appear to be the most appropriate for the screening of DM2 in the population under study, with emphasis on the fact that the value recommended for CG is 5 mg/dl higher than that for PG, in contrast to WHO recommendations.

Trends in aortic aneurysm- and dissection-related mortality in the state of São Paulo, Brazil, 1985–2009: multiple-cause-of-death analysis

Background: Aortic aneurysm and dissection are important causes of death in older people. Ruptured aneurysms show catastrophic fatality rates reaching near 80%. Few population-based mortality studies have been published in the world and none in Brazil. The objective of the present study was to use multiple-cause-of-death methodology in the analysis of mortality trends related to aortic aneurysm and dissection in the state of Sao Paulo, between 1985 and 2009. Methods: We analyzed mortality data from the Sao Paulo State Data Analysis System, selecting all death certificates on which aortic aneurysm and dissection were listed as a cause-of-death. The variables sex, age, season of the year, and underlying, associated or total mentions of causes of death were studied using standardized mortality rates, proportions and historical trends. Statistical analyses were performed by chi-square goodness-of-fit and H Kruskal-Wallis tests, and variance analysis. The joinpoint regression model was used to evaluate changes in age-standardized rates trends. A p value less than 0.05 was regarded as significant. Results: Over a 25-year period, there were 42,615 deaths related to aortic aneurysm and dissection, of which 36,088 (84.7%) were identified as underlying cause and 6,527 (15.3%) as an associated cause-of-death. Dissection and ruptured aneurysms were considered as an underlying cause of death in 93% of the deaths. For the entire period, a significant increased trend of age-standardized death rates was observed in men and women, while certain non-significant decreases occurred from 1996/2004 until 2009. Abdominal aortic aneurysms and aortic dissections prevailed among men and aortic dissections and aortic aneurysms of unspecified site among women. In 1985 and 2009 death rates ratios of men to women were respectively 2.86 and 2.19, corresponding to a difference decrease between rates of 23.4%. For aortic dissection, ruptured and non-ruptured aneurysms, the overall mean ages at death were, respectively, 63.2, 68.4 and 71.6 years; while, as the underlying cause, the main associated causes of death were as follows: hemorrhages (in 43.8%/40.5%/13.9%); hypertensive diseases (in 49.2%/22.43%/24.5%) and atherosclerosis (in 14.8%/25.5%/15.3%); and, as associated causes, their principal overall underlying causes of death were diseases of the circulatory (55.7%), and respiratory (13.8%) systems and neoplasms (7.8%). A significant seasonal variation, with highest frequency in winter, occurred in deaths identified as underlying cause for aortic dissection, ruptured and non-ruptured aneurysms. Conclusions: This study introduces the methodology of multiple-causes-of-death to enhance epidemiologic knowledge of aortic aneurysm and dissection in São Paulo, Brazil. The results presented confer light to the importance of mortality statistics and the need for epidemiologic studies to understand unique trends in our own population.

Thrombotic obstruction of the central venous catheter in patients undergoing hematopoietic stem cell transplantation

This is an integrative literature review with the aim of summarizing the prevention measures and treatment of thrombotic obstruction of long-term semi-implanted central venous catheters, in patients undergoing hematopoietic stem cell transplantation. The sample consisted of seven studies, being two randomized controlled clinical trials, three cohort studies and two case series. Regarding the prevention measures, one single study demonstrated effectiveness, which was a cohort study on the oral use of warfarin. In relation to the treatment measures, three studies evidenced effectiveness, one highlighted the efficacy of streptokinase or urokinase, one demonstrated the benefit of using low-molecular-weight heparin and the other treated the obstruction with heparin or urokinase. Catheter patency research shows a restricted evolution that does not follow the evolution of transplantations, mainly regarding nursing care.