Rafael Ponikvar

Effect of Local Physical Training on the Forearm Arteries and Veins in Patients with End-Stage Renal Disease

Aim: We investigate the effects of local training on the forearm vessels in patients with end-stage renal disease. Methods: Fourteen hemodialysis patients were included. Handgrip training was performed for 8 weeks. The following parameters were measured at the beginning of the study and 4 and 8 weeks later: forearm circumference, maximal handgrip strength, and artery and vein parameters, including endothelium-dependent and endothelium-independent vasodilatation (using ultrasound and duplex Doppler scanning). Results: The maximal handgrip strength increased significantly. The radial artery diameters were significantly higher after 8 weeks of training. The endothelium-dependent vasodilatation was found to be significantly increased after 4 and 8 weeks of training. The maximal vein diameters increased significantly with training, with preserved distensibility. Conclusions: The present study suggests that regular handgrip training increases the diameters of forearm vessels. It also improves endothelium-dependent vasodilatation. These changes point to the possible beneficial effects of daily handgrip training in chronic renal failure patients before arteriovenous fistula construction.

Temporary Hemodialysis Catheters as a Long-term Vascular Access in Chronic Hemodialysis Patients

Abstract:  The objective was to review our experience with temporary, precurved, jugular catheters used for long‐term vascular access in chronic hemodialysis patients. Thirty chronic hemodialysis patients, 14 men and 16 women, with an average age of 65.3 ± 13.5 years (30–90 years), treated by dialysis for 1 month to 30 years (average ± SD, 6.3 ± 8.1 years), had single lumen, ‘temporary’ precurved non‐tunneled jugular catheters placed into the right jugular vein as permanent vascular access, with 4% trisodium citrate as a locking solution and mupirocin at the exit site. Hemodialysis catheters were used for vascular access on average for 9.1 ± 6.5 months, (1–22.7 months), and for a total of 271.7 months (8151 days). Average catheter functioning time was 3.1 ± 1.9 months (0.5–10 months). The total number of side‐effects was 55 (6.7/1000 catheter days), including 26 cases of thrombosis (3.2/1000 catheter days), 9 ruptures of the catheter (1.1/1000 catheter days), 15 catheter malfunctions (1.8/1000 catheter days), 2 exit site infections (0.2/1000 catheter days), 2 bacteremias (0.2/1000 catheter days), 1 avulsion of the catheter (0.1/1000 catheter days), and 2 catheters were removed because an AV fistula was successfully used. In 21 patients single‐needle hemodialysis was performed, mean blood flow 251 ± 16 mL/min (250–300), mean Kt/V 0.96 ± 0.16 (0.72–1.27) and in 9 patients double‐needle hemodialysis was performed (catheter and peripheral vein) with mean blood flow 252 ± 14 mL/min (200–300), mean Kt/V 1.63 ± 0.25 (1.21–1.96). ‘Temporary’ jugular single lumen non‐tunneled hemodialysis catheters, with 4% citrate as locking solution and mupirocin ointment at the exit site provided good long‐term vascular access with acceptable functioning time and low infection rate. The main reasons for catheter exchange or removal were malfunction and mechanical damage of the catheter.

Treatment of hyperlipidemic acute pancreatitis with plasma exchange: a single-center experience.

Of the cases of acute pancreatitis, 1–7% are caused by severe hypertriglyceridemia and can be treated with plasma exchange (PE). We report on a large series of patients with acute hyperlipidemic pancreatitis (HLP) treated with PE. In the 1992–2008 period, 50 patients (45 ± 8 years old, 92% male) with acute HLP were treated with PE, during which 1–2 plasma volumes were exchanged. Heparin was used as anticoagulant in 85% of the procedures, and citrate in the rest. Cholesterol and triglycerides were measured before and after PE. In the 2003–2008 cohort of 40 patients, we retrospectively recorded an Acute Physiology and Chronic Health Evaluation II (APACHE II) score at the first PE session, hospital mortality, and length of hospital stay. A total of 79 PE treatments were done, 1–5 per patient. The volume exchanged was 4890 ± 1300 mL over a duration of 3.5 ± 2 h. During the first PE, the triglycerides were lowered from 58.9 ± 40.8 to 10.8 ± 10.8 mmol/L, and the total cholesterol was lowered from 20.0 ± 7.6 to 5.7 ± 4.3 mmol/L. In 10% of the procedures the plasmafilter was replaced, and in 3% the filter was clotted. Hypotension occurred in 3% of PE and there was one case of gastrointestinal bleeding after PE with heparin anticoagulation. In the 2003–2008 cohort, the median APACHE II score was 5 (range 0–15), the median overall hospital stay was 18 days (range 3–142 days) and the hospital mortality was 15%. To conclude, in acute hyperlipidemic pancreatitis, one to two plasma exchanges effectively reduce the serum triglyceride level. There is a low rate of procedure‐related complications. A mortality rate of 15% is considerable.

Regular Exercise as a Part of Treatment for Patients With End‐stage Renal Disease

Abstract:  Physical inactivity and its negative influence on health and the quality of life is a common problem generally, especially in patients with chronic illness and also in patients with end‐stage renal disease. Motivation for regular physical exercise could be a problem. A supervised outpatient program in a rehabilitation center, a home exercise rehabilitation program and an exercise rehabilitation program during the first hours of the hemodialysis treatment with a bed bicycle ergometer in the renal unit could be carried out. Low intensity aerobic activity has a favorable effect on cardiovascular risk factor, and gymnastics to increase strength, flexibility and coordination, as well as relaxation techniques are very effective exercises in a rehabilitation program. The positive influence of individual regular exercise on health, quality of life, physical exercise capacity, endurance, muscle strength, social, professional and emotional status is also very high in patients. Side effects of exercise are very rare.

Surgical Salvage of Thrombosed Arteriovenous Fistulas and Grafts

Abstract:  Our clinical experience with surgical salvage of thrombosed arteriovenous (AV) fistula and grafts, performed by a skilled interventional nephrologist is presented. A total of 286 surgical interventions were performed in 246 chronic hemodialysis patients aged 12–87 years (55 ± 16 years), 268/286 (93.7%) in AV fistulas, 18/286 (6.3%) in grafts, and analyzed retrospectively. A subgroup of 61 procedures was analyzed prospectively. The type of procedure, immediate success and patency after surgery were evaluated. Thrombectomy with reanastomosis was performed in 197/286 (68.9%) and simple thrombectomy in 89/286 (31.1%) of the procedures. The time from thrombosis to surgery was 1–60 days (3.7 ± 1.8). Immediate success was achieved in 258/286 (90.2%) of surgical procedures, 95.5% (189/198) in thrombectomies with reanastomosis, and 77.5% (69/89) in simple thrombectomies. Primary and secondary patency rates for AV fistulas after surgical salvage at 3, 6, 9, and 12 months were 93.1, 84.0, 78.3, 75.0% and 96.6, 88.0, 78.3, 77.3%, respectively. In order to maintain secondary patency, 1.15 surgical procedures per AV fistula were needed. The time to thrombosis in grafts was on average 10.2 months, primary and secondary functioning time from thrombectomy (until the end of observation period) was from 1 to 19 months (average 6.9 ± 6.3 months) and from 5.5 to 19 months (average 9.1 ± 5.6 months), respectively. In 7/16 (43.8%) surgical procedures, transluminal angioplasty and in 3/16 endovascular stent was placed after angioplasty. To maintain secondary patency, 2.3 surgical procedures per graft were needed. The surgical salvage of thrombosed AV fistulas and grafts, performed by a skilled interventional nephrologist, is successful in the short and long‐term.

Effects of Handgrip Training and Intermittent Compression of Upper Arm Veins on Forearm Vessels in Patients With End‐stage Renal Failure

Abstract:  The purpose of our study was to assess the influence of handgrip training and intermittent compression of the upper arm veins on forearm arteries and veins. Eighteen chronic hemodialysis patients performed daily handgrip training for 8 weeks using a rubber ring, together with daily intermittent compression of the upper arm veins by elastic band. The forearm circumference, maximal handgrip strength, and arterial and vein parameters, including endothelium‐dependent vasodilatation, were measured at the beginning, and after 4 and 8 weeks (using ultrasound scanning). The maximal handgrip strength and forearm circumference increased significantly. The radial artery diameters were significantly higher after 8 weeks of training (1.89 mm ± 0.10 at the beginning, 1.95 ± 0.10 mm after 8 weeks, P = 0.007), and endothelium‐dependent vasodilatation was also found to be increased after 4 and 8 weeks of both activities. The venous parameters before tourniquet placement increased significantly after 8 weeks (2.40 ± 0.16 mm at the beginning, 2.62 ± 0.17 mm after 8 weeks, P = 0.014), and the venous parameters after tourniquet placement increased significantly after 4 and 8 weeks (3.36 ± 0.17 mm at the beginning, 3.51 ± 0.18 mm after 4 weeks, P = 0.009), 3.68 ± 0.18 mm after 8 weeks, P < 0.001). The distensibility of veins was preserved. Our results showed that handgrip training and intermittent compression of the upper arm veins, performed daily, increase the diameter of forearm arteries and veins and improve endothelium‐dependent vasodilatation.

Factors Affecting Outcome in Acute Hypertriglyceridemic Pancreatitis Treated with Plasma Exchange: An Observational Cohort Study

Objectives The optimal therapy for hypertriglyceridemic acute pancreatitis, especially the role of plasma exchange (PE), is not entirely clear. The aim of our large, single-center, observational, cohort study was to analyze the factors affecting outcome in hypertriglyceridemic pancreatitis treated with PE. Methods We included 111 episodes of hypertriglyceridemic pancreatitis treated with PE, which occurred in 103 different patients. The Acute Physiology and Chronic Health Evaluation (APACHE) II score, triglycerides, delay to first PE, and PE treatment details were retrospectively obtained from the patients’ records. The main outcome measures were length of hospitalization and in-hospital mortality. Results The patients were 47±9 years old and the median APACHE II score at first PE was 4 (inter-quartile range (IQR) 2–7). There was a seasonal variation in the incidence of hypertriglyceridemic pancreatitis, and the recurrence rate was 1.6% per year. Triglycerides at presentation did not correlate with APACHE II or influence the outcome. The mean reduction in triglycerides during PE was 59% (from 44±31 to 18±15 mmol/l), which was twice the reduction observed during conservative treatment (27% daily). The median hospital stay was 16 days (IQR 10–24) and in-hospital mortality was 5%. The median delay to first PE was 35 hours (IQR 24–52), and there was no difference in mortality in the early and late PE groups (7% vs. 6%, p = 0.79). The group with citrate anticoagulation during PE had a significantly lower mortality than the group with heparin anticoagulation (1% vs. 11%, p = 0.04), and citrate was an independent predictor also in the multivariate model (p = 0.049). Conclusions PE effectively reduced serum triglycerides faster than could be expected with conservative treatment. The delay in PE therapy did not influence survival. We found that citrate anticoagulation during PE was associated with reduced mortality, which should be confirmed in a randomized study.

High cut-off membrane hemodiafiltration in myoglobinuric acute renal failure: a case series.

Acute renal failure is a major complication of rhabdomyolysis. New membranes for hemodialysis have been developed with a high cut‐off pore size allowing efficient removal of myoglobin. We report on six patients treated by hemodiafiltration with a high cut‐off membrane (HCO‐HDF) for myoglobinuric acute renal failure. Rhabdomyolysis was caused by infection in two patients, by a statin in one patient and a non‐traumatic crush in another, and followed cardiovascular surgery in two others. Ten HCO‐HDF procedures were performed. A high cut‐off hemofilter was used, with citrate anticoagulation and postdilutional fluid substitution of 2–3 L/h, dialysate flow 500 mL/min, and blood flow within 250–300 mL/min. Albumin losses were replaced by infusion of human albumin solution, and the mean myoglobin reduction ratio was 77% (range, 62–89%). An excellent clearance of 81 mL/min (range 42–131 mL/min) was achieved. Nearly 5 g of myoglobin was removed into the dialysate collected in one of the procedures. A high rebound in serum myoglobin, on average to 244% of the post‐procedure myoglobin level, was observed. The four patients alive at the time remained anuric for a week. Slow myoglobin elimination with a mean half‐time of 39 h (range 19–59 h) was observed in that period. Highly efficient myoglobin removal by high cut‐off membrane hemodiafiltration was demonstrated in our patients. Rapid redistribution from the extracellular fluid and sustained myoglobin release were suggested by the high rebound observed. Elimination of myoglobin within the body was shown in our study to occur slowly during the period of anuria.

Comparison of Citrate Anticoagulation During Plasma Exchange With Different Replacement Solutions

The aim of our retrospective study was to compare the application of regional citrate anticoagulation and citrate‐related side‐effects in plasma exchange (PE) with different replacement solutions. We included 35 patients treated with PE with regional citrate anticoagulation and divided them into three groups according to the replacement solution used: human albumin (HA) group (40 PE treatments), fresh frozen plasma (FFP) group (86 PE treatments), or a combination of the two (63 PE treatments). The citrate anticoagulation parameters, ionized calcium and metabolic consequences of citrate were compared. The blood flow and citrate infusion rates were similar in all groups. To maintain comparable values of ionized calcium during PE, significantly more calcium was replaced in the combination group (7.6 ± 1.3 vs. 6.2 ± 2.7 mL/h, P < 0.001) and even more in the FFP group (10.8 ± 1.7 vs. 6.2 ± 2.7 mL/h, P < 0.001) as compared to the HA group. The pH increased significantly and comparably in all groups, but the increase in bicarbonate was significantly higher in the FFP group (4.4 ± 3.0 vs. 2.6 ± 2.1 mmol/L, P = 0.01). A short, heparin‐free hemodialysis session was performed after the PE treatment, because of significant metabolic alkalosis (mainly with pH ≥ 7.5), significantly more often in the FFP group (14/86 PE, P < 0.01) as compared to the HA group (0/40), and only rarely in the combination group (2/63). To conclude, when FFP is used as a replacement solution during PE with citrate anticoagulation, significantly more calcium needs to be replaced and the increase in bicarbonate is greater during PE. The additional citrate contained in FFP, combined with frequent PE treatments, often causes significant metabolic alkalosis, which can be efficiently corrected with a short heparin‐free hemodialysis.

Citrate anticoagulation for single-needle hemodialysis: safety and efficacy.

Abstract:  Single‐needle hemodialysis can be the only option in some patients and requires full heparinization. The aim of our retrospective clinical study was to evaluate the safety and efficacy of regional citrate anticoagulation for single‐needle hemodialysis. Citrate anticoagulation was performed during 41 single‐needle hemodialysis procedures in 24 patients at risk of bleeding, using 4% trisodium citrate, 1 M CaCl2 and calcium‐free dialysate. Safety was assessed by the percentage of procedures that were terminated prematurely or changed to another modality due to citrate‐related complications and by incidence of important hypocalcemia. Efficacy was evaluated by visually assessing  clot  formation  in  the  circuit.  Five  per  cent  of  the procedures were terminated prematurely. Important hypocalcemia was recorded in 34% of the procedures. Anticoagulation was suboptimal in 17% of the procedures, but none of the systems clotted. The median dialyzer assessment grade was excellent. The average protocol parameters  were:  blood  flow  244 ± 27 mL/min,  starting  rate of citrate 191 ± 19 mL/h, starting rate of calcium 6.7 ± 1.1 mL/h. In the first hour, ionized calcium decreased in 67% of the procedures by 0.08 ± 0.05 mmol/L. During the entire procedure, ionized calcium decreased in 80% of the cases by 0.17 ± 0.09 mmol/L. There was a significant, but small increase in sodium (135 ± 4 vs 137 ± 4 mmol/L) and no increase in bicarbonate. Citrate anticoagulation during single‐needle hemodialysis, according to our protocol, is safe and effective. Close monitoring of ionized calcium is mandatory. The calcium infusion rate should frequently be increased to correct hypocalcemia. The increased starting rate of calcium should be evaluated.