The present series of in vivo experiments in healthy subjects, were performed to investigate wall stiffness in peripheral vessels and how this modality adapts to iterative increments or sustained reductions in local intravascular pressures. Vascular stiffness was measured as changes in arterial and venous diameters, and in arterial flow, during graded increments in distending pressures in the vasculature of an arm or a lower leg. In addition, effects of intravascular pressure elevation on flow characteristics in veins, and on limb pain were elucidated. Arteries and veins were stiffer (i.e. pressure distension was less) in the lower leg than in the arm. The pressure-induced increase in arterial flow was substantially greater in the arm than in the lower leg, indicating a greater stiffness in the arterioles of the lower leg. Prolonged reduction of intravascular pressures in the lower body, induced by 5 wks of sustained horizontal bedrest (BR), decreased stiffness in the leg vasculature. BR increased pressure distension in the tibial artery threefold and in the tibial vein by 86 %. The pressure-induced increase in tibial artery flow was greater post bedrest, indicating reduced stiffness in the arterioles of the lower leg. Intermittent increases of intravascular pressures in one arm (pressure training; PT) during a 5-wk period decreased vascular stiffness. Pressure distension and pressure-induced flow in the brachial artery were reduced by about 50 % by PT. PT reduced pressure distension in arm veins by 30 to 50 %. High intravascular pressures changed venous flow to arterial-like pulsatile patterns, reflecting propagation of pulse waves from the arteries to the veins either via the capillary network or through arteriovenous anastomoses. High vascular pressures induced pain, which was aggravated by BR and attenuated by PT; the results suggest that the pain was predominantly caused by vascular overdistension. In conclusion, vascular wall stiffness constitutes a plastic modality that adapts to meet demands imposed by a change in the prevailing local intravascular pressure. That increased intravascular pressure leads to increased arteriolar wall stiffness supports the notion that local pressure load may serve as a “prime mover” in the development of vascular changes in hypertension. / medicine doktorsexamen QC 20101109

SAMMANFATTNING Bakgrund: PICC är en central infart som används inom vården för att kunna ge kärlretande läkemedel. Komplikationer vid användning av PICC kan vara infektion, trombos, tromboflebit eller stopp i katetern.  Syfte: Syftet med studien är att undersöka förekomsten av komplikationer av PICC hos onkologiska patienter samt för att se om det finns några skillnader mellan olika diagnosgrupper och behandlingar med avseende på förekomsten av djupa ventromboser (DVT) och infektioner. Syftet är också att ta reda på hur länge en PICC sitter och hur vanligt det är att en PICC felplaceras.  Metod: Metoden som används är en retrospektiv, deskriptiv, kvantitativ undersökning. I studien ingår alla onkologpatienter som fått en PICC år 2009-2011 (n=677). Data samlades in med hjälp av journalgranskning.  Resultat: Förekomsten av DVT var 5,6 %. Patienter som fick behandling med Capecitabin hade statistiskt signifikant mer DVT jämfört med andra behandlingar. Patienter som fick behandling med R-CHOP hade statistiskt signifikant mindre DVT jämfört med andra behandlingar. Antalet infektioner var 3 %. Stopp i katetern drabbade 1,8 % av patienterna, 17 % hade besvär med rodnad under förbandet, 12 % av alla katetrar åkte ut 4 cm eller mer och 2,5 % av katetrarna felplacerades vid inläggningen. En PICC var insatt i medelvärde 92 dagar, median 105 dagar.  Slutsats: Förekomsten av komplikationer av PICC var låg hos onkologiska patienter med undantag för hudbesvär som förekom hos var sjätte patient. Behandlingar innehållande Capecitabin förefaller öka risken för DVT men fler studier behövs för att öka kunskaperna om detta. PICC är en säker venös infart vid behandling med cytostatika. / ABSTRACT Background: PICC (peripherally inserted central catheter) is a central line used in healthcare to provide vascular irritant drugs. Complications with PICC can be infection, thrombosis, thrombophlebitis or occlusion of the catheter.  Aim: The aim of the study is to examine the incidence of complications of PICC in oncology patients and to see if there are any differences between diagnostic groups and treatments for the presence of deep venous thrombosis (DVT) and infection. The aim is also to find out for how long time a PICC is inserted and how common it is for a PICC misplaced.  Method: The method used is a retrospective, descriptive, quantitative survey. The study includes all oncology patients who received a PICC years 2009-2011 (n=677). Data were collected through medical record review.  Results: The incidence of DVT was 5,6 %. Patients treated with Capecitabin had statistically significantly more DVT compared with other treatments. Patients treated with R-CHOP had statistically significantly less DVT compared with other treatments. The incidence of infections was 3 %. Occlusion of the catheter affected 1,8 % of patients, 17 % had problems with redness under the dressing, 12 % of all catheters went out four cm or more and 2,5 % of the catheters were misplaced at insertion. A PICC was inserted in mean 92 days, median 105 days.  Conclusion: The complication rate of PICC was low in oncology patients with the exception of skin problems that occurred in every sixth patient. Treatments containing Capecitabin appears to increase the risk of DVT but more studies are needed to raise awareness of this. PICC is a safe venous access for chemotherapy.

No description available.

Despite over a century of inquiry, the mechanisms that achieve the close matching of oxygen supply to demand during exercise remain elusive. It has been proposed that in addition to its role as the primary oxygen carrier, the red blood cell (RBC) functions as a roving oxygen sensor, linking the oxygen demand at the muscle with oxygen delivery via the circulation (Ellsworth et al. 1995). It is hypothesised that the RBC would release adenosine triphosphate (ATP) in proportion to the number of unoccupied binding sites on the haemoglobin molecule as it traverses regions of high oxygen demand such as the microcirculation of active skeletal muscle. ATP would then stimulate the release of vasodilatory substances from the endothelium which would diffuse to neighbouring vascular smooth muscle resulting in vasodilation and an increase in blood flow in accordance with the oxygen demand set by the muscle. The first step in establishing a role for this mechanism during exercise in humans is to determine whether ATP increases in the venous blood draining an active muscle bed. Based on the handful of published studies, there is an increase in ATP concentration in the femoral vein during knee extensor exercise. However the response has not been studied in other vascular beds in humans. As such, the main aim of this thesis was to measure the ATP response to dynamic handgrip exercise. Secondary aims were to determine whether the response was modified by hypoxia, and to provide information about the timing of the changes in ATP concentration during a bout of handgrip exercise. These questions were addressed in Studies 3 and 4. Because blood flow is central to this hypothesis, a substantial portion of this thesis was also associated with the measurement of forearm blood flow (FBF) using venous occlusion strain gauge plethysmography (VOSGP), and this was conducted in Studies 1 and 2. VOSGP is based on the assumption that with venous outflow prevented, any increase in limb volume is proportional to the rate of arterial inflow. The rate of arterial inflow is determined as the slope of the change in limb volume over time. The slope must be calculated over the initial linear portion of this relationship, when arterial inflow is unaffected by the inevitable rise in venous pressure associated with venous occlusion. VOSGP was initially used to measure blood flow at rest and in response to pharmacological interventions which produced only modest increases in arterial inflow (Joyner et al. 2001). However, measurement of the high rates of arterial inflow that occur with exercise may challenge the limits of this technique. Tschakovsky et al. (1995) reported a marked reduction in arterial inflow over the first four cardiac cycles during venous occlusion following static handgrip exercise that elevated blood flow to 22-24 mL/min/100mL. Only during the first cardiac cycle was arterial inflow unaffected by cuff inflation. As such, the window for measuring high rates of arterial inflow may be very brief. Therefore Study 1 aimed to determine whether blood flow could be measured using VOSGP across the range of arterial inflows that occur with dynamic handgrip exercise. Participants (n = 7) completed four, five-minute bouts of dynamic handgrip exercise at 15, 30, 45, and 60% of maximum voluntary contraction (MVC). FBF was measured using VOSGP at rest, and following five minutes of dynamic handgrip exercise. The slope of the change in limb volume was measured over the first one, two, three, and four consecutive cardiac cycles following the onset of occlusion. FBF was 2.5 ± 0.5 at rest, and 16.5 ± 4.9, 24.9 ± 9.4, 44.1 ± 22.0, and 57.8 ± 14.9 mL/min/100mL following five minutes of exercise at 15, 30, 45, and 60% MVC, respectively. At rest, arterial inflow decreased across the four cardiac cycles (P = 0.017 for the main effect), however post-hoc pairwise comparisons revealed no significant differences between any of the cardiac cycles. In contrast, the inclusion of two, three, or four cardiac cycles at 30 and 60% MVC, and three or four cardiac cycles at 15 and 45% MVC resulted in reductions in calculated arterial inflow compared with using the first cardiac cycle alone (P > 0.05). The inclusion of just two cardiac cycles resulted in a 9-26% reduction in calculated arterial inflow depending on the workload. This reduction was even more pronounced when three (19-40%) or four (26-50%) cardiac cycles were included. In conclusion, resting FBF can be calculated over at least four cardiac cycles during venous occlusion at rest. However, exercising FBF should be calculated from the first cardiac cycle only following dynamic handgrip exercise across the range of intensities used in this study. This extends the findings of Tschakovsky et al. (1995) who demonstrated this effect following handgrip exercise at a single intensity. Study 2 was designed to establish the FBF response to dynamic handgrip exercise, whether the workloads produced different blood flow responses, and to establish the within- and between-day reproducibility of FBF measured using VOSGP. In Part A (within-day reproducibility), participants (n = 7) completed three trials of dynamic handgrip exercise at four intensities (15, 30, 45, and 60% MVC), with each exercise trial separated by 10 minutes of rest. In Part B (between-day reproducibility) participants (n = 7) completed three trials of dynamic handgrip exercise at 15, 30, and 45% MVC on three separate days within a two week period. FBF was measured at rest, and each minute of exercise during brief (5-7 second) pauses in contractions. FBF response. FBF increased from rest at all workloads (P > 0.05), and then plateaued between Minutes 1 to 5 at the 15 and 30% MVC workloads and between Minutes 2 and 5 at the 45% workload (P > 0.05 for each minute compared to Minute 5). Too few participants completed the 60% workload to permit any statistical analysis. FBF reached values of 13.0 ± 2.0, 26.8 ± 8.4, 44.8 ± 14.9, and 52.9 ± 5.1 mL/min/100mL in the final minute of exercise at the 15, 30, 45, and 60% MVC workloads. FBF was different between the 15, 30, and 45% workloads by Minute 3 (P > 0.05). Reproducibility. The within-day test-retest reliability of exercising FBF was poor to moderate (ICC = 0.375-0.624) with individual coefficients of variation (CVs) ranging from 6-25%, 9-23%, and 9-31% for the 15, 30, and 45% MVC workloads, respectively. The between-day test-retest reliability for resting FBF was moderate (ICC = 0.644, P > 0.05; individual CVs between 1 and 31%). Between-day test-retest reliability for exercising FBF was poor to moderate (ICC = 0.381-0.614), with individual CVs ranging from 14-24%, 8-23%, and 6-18% for the 15, 30, and 45% workloads, respectively. It was concluded from this study that VOSGP provides adequately reproducible measurements to detect changes in FBF of the magnitude seen between workloads in this study. However, the variability in the measurement precludes its use when smaller differences are of interest. Based on the previous findings reporting an increase in ATP concentration during dynamic knee extensor exercise in the leg (Gonzalez-Alonso et al. 2002; Yegutkin et al. 2007), Study 3 was designed to determine whether ATP concentration increased in the venous effluent during dynamic handgrip exercise in the forearm. Since the deoxygenation of haemoglobin is a primary stimulus for ATP release from red blood cells, a further aim was to determine whether this response was augmented by systemic hypoxia. Participants (n = 6) completed four, five-minute bouts of dynamic handgrip exercise at 30, 45, 65, and 85% MVC under normoxia (inspired oxygen fraction = 0.21) and hypoxia (inspired oxygen fraction = 0.12). Blood samples for the determination of ATP concentration were drawn at rest and 180 seconds after the onset of exercise at each workload from a catheter inserted into a forearm vein. Venous plasma ATP concentration at rest was 0.28 ± 0.11 μM/L and remained unchanged during exercise at workloads up to 85% MVC (P > 0.05). Systemic hypoxia, sufficient to reduce arterial oxygen saturation to 83 ± 2%, also failed to alter the plasma ATP concentration (P = 0.148). The lack of a change in ATP concentration was unexpected but there are several possible explanations. It is possible, although unlikely, that ATP was not released in the forearm microcirculation. The previous demonstration that ATP increased in response to static handgrip exercise (Forrester and Lind 1969) would suggest that this was probably not the case. When considered in the context of the findings from Study 4, the most plausible explanation is that a less than optimal blood sampling site may have hindered the measurement of a change in ATP. The blood flow response at the onset of dynamic exercise in the forearm is at least biphasic; Phase 1 describes the immediate, large increase in blood flow within 2 seconds of the onset of exercise and is believed to be governed by mechanical factors whereas Phase 2 has a latency of ~20 seconds and describes a further, slower increase until blood flow reaches steady state (Saunders et al. 2005b). The temporal characteristics of Phase 2, along with the fact that blood flow during this phase is closely related to the metabolic rate of the muscle, suggest regulation by metabolic factors. Currently there is scant evidence detailing the time course of vasodilator release, although it is important to demonstrate that the release of a vasodilatory substance precedes the blood flow response it is proposed to influence (Delp 1999). ATP is released from red blood cells in proportion to the offloading of oxygen and a reduction in the oxygen content of venous blood draining a muscle bed occurs within 10 seconds of the onset of exercise. Thus the release of ATP should follow soon thereafter. As such, Study 4 was designed to determine whether ATP increased in the venous effluent of the forearm following 30 and 180 seconds of dynamic handgrip exercise at 45% MVC; and whether this increase corresponded with a decrease in venous oxygen content. Participants (n = 10) completed two bouts of dynamic handgrip exercise at 45% MVC; the first was one minute in duration, and the second was four minutes in duration. Venous blood samples for the determination of ATP and venous oxygen content were drawn at rest and during exercise from a catheter inserted in a retrograde manner into the median cubital vein. Arterialised samples for the estimation of arterial blood gases and ATP concentration were obtained from the non-exercising hand. ATP concentration in arterialised blood from the non-exercising arm was 0.79 ± 0.30 μM/L at rest and remained unchanged at both time points during exercise (P > 0.05). ATP concentration in the venous blood of the exercising arm increased from 0.60 ± 0.17 μM/L at rest to 1.04 ± 0.33 μM/L 30 seconds after the onset of exercise (P > 0.05), and remained at this higher level after 180 seconds (0.92 ± 0.26 μM/L, P > 0.05 versus rest). This corresponded with a decrease in venous oxygen content from 103 ± 23 mL/L at rest to 68 ± 16 mL/L 30 seconds after the onset of exercise (P > 0.05) and 76 ± 15 mL/L (P > 0.05 versus rest) 180 seconds into exercise. Furthermore, at 180 seconds of exercise, ATP concentration was moderately and inversely related to venous oxygen content (r = -0.651, p > 0.05). In conclusion, this study provides the first evidence that ATP concentration is increased in the blood draining the exercising forearm muscles in response to dynamic handgrip exercise. The finding that ATP concentration was increased just 30 seconds after the onset of exercise is also novel, and particularly interesting in the context of the recently reported dynamic response characteristics of the forearm blood flow response. In conclusion, the work contained within this thesis provides several important findings. The first study has provided evidence that measuring high rates of arterial inflow using VOSGP is possible, but that the window for making these measurements is small, probably as brief as a single cardiac cycle. The second study demonstrated that while the reproducibility of forearm blood flow measurements using VOSGP is poor, it is adequate to detect the large changes that occurred between workloads. However, VOSGP cannot be used to detect more modest differences. Common to both Study 3 and 4 was the measurement of ATP at rest, and 180 seconds after the onset of dynamic handgrip exercise at 45% MVC. The primary difference was the position of the catheter which was inserted in an antegrade manner in Study 3, and in a retrograde manner in Study 4. Since ATP was unchanged in Study 3 but increased under similar conditions in Study 4, it is likely that ATP was also released during exercise in Study 3, but that a less than optimal blood sampling site precluded its measurement. This illustrates the necessity to sample blood from as close as possible to the probable site of ATP release, the muscle microcirculation. The most important and novel findings from this body of work come from Study 4. This is the first study to demonstrate an increase in ATP concentration in the forearm in response to dynamic handgrip exercise. However, the most novel finding was that ATP concentration was elevated just 30 seconds after the onset of exercise. Such an early increase has not previously been reported during dynamic exercise in any vascular bed. This is an important finding since establishing the time course for the release of vasodilatory substances is critical to our understanding of the mechanisms that regulate blood flow during exercise.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Washington, 2008. / Vita. Includes bibliographical references (leaves 64-74).

No description available.

The present thesis deals with the issue of central venous catheter treatment in intensive and metabolic care, as well as the complications, which can accompany central venous cannulation and thus affect the possible period of using central venous catheter. The theoretical part tries to summarize the information concerning the issues of central venous catheters and their treatment. It also contains essential physiological and anatomical notes concerning central venous cannulation and a historical summary with regard to the present knowledge. The first part of the empirical section of the research follows the medical approach in various departments of the 4th Department of Internal Medicine of the General Teaching Hospital in Prague, as well as their influence on prevention and the rise of complications. The goal of the second part of the research is to make suggestions for treatment of central venous catheters, which could help to improve nursing care and the using period of catheter. The conclusion evaluates, whether the recommendations have at least partially become a part of the nursing care and if they have helped to resolve the areas of concern or not. Key words Central venous catheter, nursing care, complications of central venous catheter, central venous access.

Chronic venous disease (CVD) affects about 0.5 to 3.0% of the population. The venous ulcer (UV) is the most advanced stage of CVD and affects the patient-age, worsening their quality of life and burdens the welfare system. Venous reflux is related to the genesis, development and maintenance of UV. To evaluate venous reflux in patients with UV. A cross-sectional study was performed, observational Vascular Surgery Service at the Federal University of Sergipe - Aracaju-SE, in a sample of 162 patients with active UV divided into two groups for evaluation of reflux: G1 (primary etiology) and G2 ( etiopathogenesis secondary) seen consecutively in the period of 03 / 2009-10 / 2010. Five patients were excluded because they had chronic ischemia, because they have two non-recanalized vein thrombosis and one for being pregnant. We investigated the age, gender, distribution of venous reflux in the superficial venous system (SVS), the deep venous system (DVS) and perforating veins (PVs), location of reflux in the SVS, types of reflux in the saphenous vein (GSV ) and saphenous vein (VSP) and distribution of reflux in the DVS. Statistical method: the database and statistical analysis were performed using the SPSS 18.0. Quantitative variables were summarized as mean and standard deviation. Categorical variables were described by simple frequency and percentages with their respective confidence intervals for 95%. The mean age was 53.7 years with a predominance of women (79%). The distribution of reflux was observed that all patients in G1 had reflux in the SVS without reflux in the DVS, VPs with 92% in G2 and 83.3% had reflux in the SVS, with 100% DVS and 92.3% in the VPs. Regarding the location of reflux in the SVS group G1 showed reflux in 96% in GSV and 14% VSP and G2 showed reflux in GSV 70% and 13% in VSP. Considering the types of saphenous vein reflux in G1 90% of the type I had reflux in the GSV and 71.5% type IV in VSP in G2 while 84% of reflux in the GSV type I and type IV 85.7% in VSP. In Group G2 approximately 70% of patients had reflux in these veins of the legs and 54% in the popliteal veins. The superficial system reflux was present in all patients with primary venous insufficiency and in most patients with secondary failure. The finding most often found in the superficial venous system was the GSV reflux. The reflux in the GSV type I and type IV reflux in VSP findings were more often found in the superficial venous system of patients in both groups. Approximately 70% of deep venous reflux was located in the leg, the popliteal vein being the most frequently affected. / A doença venosa crônica (DVC) atinge cerca de 0,5 a 3,0% da população. A úlcera venosa (UV) é o estágio mais avançado da DVC e atinge o paciente em idade produtiva, piora a sua qualidade de vida e onera o sistema previdenciário. O refluxo venoso está relacionado com a gênese, desenvolvimento e manutenção da UV. Avaliar o refluxo venoso nos portadores de UV. Realizado estudo de corte transversal, observacional no Serviço de Cirurgia Vascular da Universidade Federal de Sergipe - Aracaju SE, em amostra de 162 pacientes com UV em atividade dividida em dois grupos para avaliação do refluxo: G1 (etiopatogenia primária) e G2 (etiopatogenia secundária) atendidos consecutivamente no período de 03/ 2009 a 10/ 2010. Foram excluídos cinco pacientes por apresentarem isquemia crônica, dois por apresentarem trombose venosa não recanalizada e um por estar gestante. Foram pesquisadas as variáveis idade, gênero, distribuição do refluxo venoso no sistema venoso superficial (SVS), no sistema venoso profundo (SVP) e em veias perfurantes (VPs); localização do refluxo no SVS; tipos de refluxo na veia safena magna (VSM) e em veia safena parva (VSP) e distribuição do refluxo no SVP. Método estatístico: o banco de dados e a análise estatística foram efetuados no programa SPSS 18.0. As variáveis quantitativas foram sumarizadas como média e desvio-padrão. As variáveis categóricas foram descritas mediante frequência simples e porcentagens com seus respectivos intervalos de confiança para 95%. A idade média foi de 53,7 anos com predomínio de mulheres (79%). Quanto a distribuição do refluxo observou-se que no G1 todos pacientes apresentaram refluxo no SVS, sem refluxo no SVP, com 92% em VPs e no grupo G2 83,3% tinham refluxo no SVS, com 100% no SVP e 92,3% VPs. Em relação a localização do refluxo no SVS do grupo G1 96% apresentaram refluxo em VSM e 14% em VSP e do G2 70% apresentaram refluxo em VSM e 13% em VSP. Considerando os tipos de refluxo em veias safenas no G1 90% apresentaram refluxo do tipo I em VSM e 71,5% do tipo IV em VSP enquanto que no G2 84% de refluxo do tipo I em VSM e 85,7% do tipo IV em VSP. No Grupo G2 aproximadamente 70% dos pacientes apresentaram refluxo em veias de pernas e destes 54% em veias poplíteas. O refluxo no sistema superficial esteve presente em todos os pacientes com insuficiência venosa primária e na maioria dos pacientes com insuficiência secundária. O achado mais frequentemente encontrado no SVS foi o refluxo VSM. O refluxo tipo I em VSM, bem como o refluxo tipo IV em VSP foram os achados mais frequentemente encontrados no SVS de pacientes dos dois grupos. Aproximadamente 70% do refluxo venoso profundo estava localizado na perna, sendo a veia poplítea a mais frequentemente acometida.

BACKGROUND:Sequential compression devices (SCDs) are commonly used for thromboprophylaxis in postoperative patients but compliance is often poor. We investigated causes for noncompliance, examining both hospital and patient related factors.METHODS:100 patients undergoing inpatient urologic surgery were enrolled. All patient had SCD sleeves placed preoperatively. Postoperative observations determined SCD compliance and reasons for non-compliance. Patient demographics, length of stay, inpatient unit type, and surgery type were recorded. At discharge, a patient survey gauged knowledge and attitudes regarding SCDs and bother with SCDs. Statistical analysis was performed to correlate SCD compliance with patient demographics / patient knowledge and attitudes regarding SCDs / and patient self-reported bother with SCDs.RESULTS:Observed overall compliance was 78.6%. The most commonly observed reasons for non-compliance were SCD machines not being initially available on the ward (71% of non-compliant observations on post-operative day 1) and SCD use not being restarted promptly after return to bed (50% of non-compliant observations for entire hospital stay). Mean self-reported bother scores related to SCDs were low, ranging from 1-3 out of 10 for all 12 categories of bother assessed. Patient demographics, knowledge, attitudes and bother with SCD devices were not significantly associated with non-compliance.CONCLUSIONS:Patient self-reported bother with SCD devices was low. Hospital factors, including SCD machine availability and timely restarting of devices by nursing staff when a patient returns to bed, played a greater role in SCD non-compliance than patient factors. Identifying and addressing hospital related causes for poor SCD compliance may improve postoperative urologic patient safety.