Complications of Permanent Hemodialysis Catheter Placement; Need for Better Pre-Implantation Algorithm?

There is a correlation between central venous cannulation and the development of central venous stenosis. Minor retrosternal vein lesions can be easily missed. Computerized tomographic (CT) venography is the diagnostic procedure of choice. The aim of this study was to examine the complications after catheter implantation in patients with prior permanent catheter placement and to evaluate present diagnostic procedures performed prior to choosing permanent access site in order to reduce possible complications after catheter placement. Complications of permanent CVC insertion in our department were analyzed between October 2011 and February 2015. We have implanted the Tesio twin catheter system and the Hickman Bard dual lumen catheter. All patients with prior permanent dialysis catheter were evaluated with color doppler, while patients with suspected central venous stenosis (CVS) or thrombosis were evaluated with phlebography or CT venography prior to catheter placement. One hundred and ninety-eight permanent dialysis catheters were placed (173 Tesio [87.4%] and 25 Hickman [12.6%]) in 163 patients. There were 125 patients (76.7%) with prior temporary catheter and 61 (48.8%) of them had more than one prior permanent catheter (1.92 catheter per person).There were 4/61 (6.5%) patients with catheter-related complications without prior phlebography and CT venography. Phlebography and CT venography were performed in 30 (24.0%) patients with suspected CVS/thrombosis and with dialysis vintage of 76.23 months (52.78-98.28). Phlebography and CT venography were more sensitive than color doppler in the detection of CVS/thrombosis in patients with prior permanent catheter placements (P < 0.001). Since this diagnostic algorithm was introduced prior to catheter placement there were no catheter insertion-related complications or dysfunctions (P < 0.001). All our procedures on patients with prior permanent catheters followed preliminary color doppler diagnostics. Nevertheless, in four cases, the vessel obstruction and abnormality led to catheter insertion-related complications. When phlebography and CT venography was performed before the procedure in patients with prior permanent catheters and one or more CVS or thrombosis, early and late catheter-related complications were avoided by careful selection of the least injured vein and planning of procedure. When planning a permanent dialysis catheter placement in patients with prior multiple CVC, phlebography and CT venography may be diagnostic procedures of choice for avoidance of early catheter dysfunction and CVC placement complications.

Hypothesis: Possible respiratory advantages for heterozygote carriers of cystic fibrosis linked mutations during dusty climate of last glaciation.

This paper puts forward a new hypothesis to interpret the high carrier frequency of CFTR mutations in individuals of European descent. The proposed heterozygote advantage factor is related to the specific climate conditions in Europe during the last 50 ky that might have heavily compromised the respiratory function of our ancestors in Eurasia. A large part of the last 50 ky was cold, and the coldest period was the Last Glacial Maximum (LGM) (26.5 to 19 kya). The global climate was dry with a dust-laden atmosphere (20 to 25 times more dust than the present level). High levels of atmospheric dust started more than 40 kya and ended less than 10 kya. Secretion of airway fluid is usually related to the submucosal tissue hydration, while salt reabsorption relies on activation of CFTRs that allow ENaCs to absorb salt and water. The water loss by evaporation depends on the air humidity and flow rate. Salt accumulation in the mucus is normally prevented by reabsorption of Na(+) and Cl(-) by epithelial cells if the presence of functional CFTRs is normal. If one gene for CFTR is mutated, the number of functional CFTRs is reduced and this limits the capacity of salt reabsorption by epithelial cells. This means that evaporation makes the airway fluid more hypertonic, and osmotic forces bring more water from the interstitial space, thus leading to a new balance in mucosal fluid traffic. Increased osmolarity and volume of airway fluid can be more moveable in cases when evaporation and dust exposure is increased. If both CFTR genes are mutated, low number of functional CFTRs diminishes salt resorption of epithelial cells. Salt accumulated in the mucous fluid within respiratory ducts, as previously described. The hypertonic ductal content forces more water and some electrolytes to enter the airway fluid from the interstitial fluid, and evaporation leads to further concentration of thick immobile mucus. The proposed interpretation is that CFTR mutations have spread among our ancestors that roamed the central Eurasia after the LGM. The heterozygote individuals might have benefitted from the limited water resorption in their respiratory mucosa that allowed improved airway cleansing.

[Temporary and permanent central venous catheters for hemodialysis]. / Primjena trajnih i privremenih centralnih venskih katetera za hemodijalizu.

The usage of temporary and permanent dialysis catheters for hemodialysis vascular access has been on continual increase. The reason for this increase is aging population on hemodialysis with blood vessels inappropriate for arteriovenous fistula creation. Complications may occur during catheter insertion as well as in the already inserted catheters, e.g., thrombosis and infections. The severity of complications is determined by experience of the operator as well as the quality and localization of blood vessels. Monitoring of dialysis catheter function, choice of the site of catheter insertion and methods of salvaging catheters from thrombosis and treating catheter-related local and systemic infections are described in this paper. Constant evaluation, proper care and hygiene of dialysis catheters are highly recommended.

Vascular access for chronic hemodialysis in a patient with epidermolysis bullosa dystrophica Hallopeau-Siemens.

Epidermolysis bullosa is a rare genetic hereditary disease characterized with mechanobullous dermatosis. Except cutaneous, these patients have various extracutaneous manifestations and some types of epidermolysis bullosa comprise almost all organ systems. Because of prolonged life span, chronic renal insufficiency has become an important cause of morbidity and death in these patients. Establishment of functional vascular dialysis access is a great challenge for both the doctors and the patients. Multidisciplinary approach is essential. We present a case of successful establishment of dialysis access via Tesio catheter in a young woman suffering from epidermolysis bullosa dystrophica Hallopeau-Siemens and end-stage renal disease. Since then, the Tesio catheter inserted via the right internal jugular vein has been the functional mean of dialysis. The patient was given the opportunity to lead a quality and active life in spite of disabling disease. Several cases of successful dialysis access establishment with dialysis catheters via central veins have been reported. We report the successful establishment of long-term dialysis access via Tesio catheter and suggest this approach as ideal for these patients. This is the first report dealing with vascular access in this group of patients.

[Stroke volume and pulse pressure variation are good predictors of fluid responsiveness in sepsis patients]. / Varijacija udarnog volumena i tlaka pulsa dobri su pokazatelji hemodinamskog odgovora na nadoknadu volumena u sepsi.

UNLABELLED: Stroke volume variation (SVV) and pulse pressure variation (PPV) are dynamic preload indicators. Specific interactions of the cardiovascular system and lungs under mechanical ventilation cause cyclic variations of SVV and PPV. Real time measurement of SVV and PPV by arterial pulse contour analysis is useful to predict volume responsiveness in septic patients. Results of a prospective, 2-year observational study conducted at Department of Anesthesiology, Resuscitation and Intensive Care, Zagreb University Hospital Center, are presented. Volume responders and non-responders were defined. Correlation between SW, PPV, stroke volume index (SVI) and other hemodynamic data in septic patients was analyzed. The study was conducted from September 2009 to December 2011. Sepsis group included 46 patients (22 male, age 46 +/- 6, APACHE II score 26 +/- 5, and 24 female, age 41 +/- 6, APACHE II score 24 +/- 4) undergoing major abdominal surgery with clinically and laboratory confirmed sepsis, defined according to the international criteria. EXCLUSION CRITERIA: patients with LVEF < 45%, atrial fibrillation, aortic insufficiency, pulmonary edema, children, pregnant women, patients on lithium therapy, and patients who did not sign informed consent. Septic patients were divided into volume responders (VR) and volume non-responders (VNR). Responders were defined as patients with an increase in SVI of > or = 15% after fluid loading. SVV, PPV and SVI were assessed by arterial pulse contour analysis using the LiDCOTM plus system continuously for 8 hours. Simultaneously, cardiac index (CI), mean arterial pressure (MAP), heart rate (HR), oxygen delivery (DO2), oxygen consumption (VO2) and central venous oxygen saturation (ScvO2) were assessed. Hemodynamic data were recorded before and after fluid administration of 500 mL of 6% hydroxyethyl starch over 30 min. All patients were sedated with midazolam (0.05-0.15 mg/kg/h). Analgesia was maintained with sufentanil (0.2-0.6 microg/kg). All patients were intubated and mechanically ventilated (IPPV; FiO2 0.4; TV 7 mL/kg; PEEP 5 cm H2O) in sinus cardiac rhythm. Circulatory unstable patients had vasoactive support and SOFA scores calculated. Ventilator settings and dosage of vasoactive drugs were all kept constant during the study. Data were compared using Student's t-test. Correlation was estimated using Pearson's coefficient. The level of statistical significance was set at P < 0.05. Positive response to fluid loading was present in 26 (57.4%) patients. Baseline SVV correlated with baseline PPV (r = 0.92, P < 0.001). SVV and PPV were significantly higher in responders than in nonresponders. SVV: 14.4 +/- 3.3 vs. 7.1 +/- 3.1; P < 0.001. PPV: 15.2 +/- 4.1 vs. 7.4 +/- 4.5; P < 0.001. Other hemodynamic parameters measured were statistically different between the two groups. Only DO2 values showed no statistical significance between the responders and non-responders. There was no difference between the area under receiver operating characteristic curves of SVV (0.96; 95% confidence interval 0.859-0.996) and PPV (1.000; 95% confidence interval 0.93-1.000). Optimal threshold value for discrimination between VR and VNR was 10% for SVV (sensitivity 96.15%, specificity 100%) and 12% for PPV (sensitivity 100%, specificity 100%). In conclusion, SVV and PPV measured by LiDCO plus system are reliable predictors of fluid responsiveness in mechanically ventilated septic patients in sinus cardiac rhythm.

[Pathophysiology of delirium]. / Patofiziologija delirija.

Today's understanding of the pathophysiological mechanisms of delirium is still limited, but there are several promising hypotheses. It is believed that biomarkers sensitive to death of neurons or glial cells indicate delirium. Several neurotransmitters are considered to be involved in the state of delirium, with greatest emphasis on acetylcholine and dopamine acting in opposite ways; acetylcholine reduces, while dopamine increases neuron excitability. Other neurotransmitters that probably play a role in the pathogenesis of delirium are GABA, glutamate and monoamines. Sepsis leading to systemic inflammatory response syndrome often presents with delirium and perhaps is the most common causal factor for delirium in intensive care unit; sedatives and analgesics are also common iatrogenic risk factors. Patients receiving benzodiazepines are more likely to have postoperative delirium than those who do not. Postoperative cognitive changes are more common in older than in younger patients, and they can be categorized as postoperative delirium, postoperative cognitive dysfunction and dementia. The mechanisms responsible for postoperative cognitive changes are not fully understood, but it is certain that they are multifactorial. Risk factors may be associated with patient characteristics, type of surgery and type of anesthesia.

Subclinical neurocognitive dysfunction after carotid endarterectomy-the impact of shunting.

BACKGROUND: Subclinical neurocognitive deficit after carotid endarterectomy (CEA) has been reported in 25% of patients. The influence of the type of anesthesia and shunting on early postoperative neurocognitive function remains unclear. Therefore, we analyzed the cognitive function after CEA using a battery of psychometric tests before surgery and on the first postoperative day. METHODS: Twenty nine patients under regional and 28 under general anesthesia were included in the study. Regional anesthesia was administered inducing a superficial cervical block, and the general anesthesia was induced using a standardized manner. Then cognitive function was tested using a battery of psychometric tests before and 24 hours after surgery. S 100 beta was determined at the same time points. RESULTS: A statistical difference was found between the results of the testing before and after CEA: decline in digit symbol test (9%), perceptual speed (6%), and spatial working memory (44%) and improvement in verbal fluency (6%) and attention (5%). The only intraoperative factor that correlated with the cognitive dysfunction was shunt insertion; patients with a shunt had a lower perceptual speed (P=0.005) and worse spatial working memory (P=0.004). No correlation was found between the type of anesthesia or S 100 beta level and any psychometric test, but these results might be influenced by the small sample size in our study. CONCLUSIONS: Shunt insertion was the only parameter correlated with cognitive decline on the first day after CEA. Regional anesthesia might offer indirect benefit because of a reduced need of shunting in wakeful patients. Larger studies are required to clarify the role of shunting and type of anesthesia in early neurocognitive deficit after CEA and its impact on the quality of life.