Long-term citrate anticoagulation for high-flux haemodialysis in a patient with heparin-induced thrombocytopenia type II

For the first time, long-term use of regional citrate anticoagulation for high-flux haemodialysis is reported in a patient with heparin-induced thrombocytopenia type II. A simple, flow-independent, citrate infusion protocol allowed efficient anticoagulation. Excellent solute removal, indicated by KT/V values of 1.52 to 1.98, was achieved. Electrolyte and acid-base balance as well as calcium homeostasis were well controlled over a period of 9 months.

Regional anticoagulation with acid citrate dextrose-A for extracorporeal photoimmunochemotherapy

BACKGROUND AND OBJECTIVES

During photopheresis, intravenous heparin is used to prevent clotting in the extracorporeal circuit. Regional citrate anticoagulation could lower the risks associated with heparin treatment.

MATERIALS AND METHODS

Four-hundred and six photophereses procedures that were anticoagulated by acid citrate dextrose-A (ACD-A) (of which 343 were performed in patients at risk for haemorrhage) were analysed together with 278 heparin-anticoagulated treatments.

RESULTS

Four-hundred and four of 406 citrate treatments were completed. Seven transient paresthesias (1.73%), five of which occurred in the first 50 treatments, were observed. Bleeding complications were noted during heparin anticoagulation (1.07%), but not during citrate anticoagulation. During photopheresis, haemoglobin values and platelet counts decreased by 11.4% and 14.6%, respectively (P < 0.0001). Twenty-four hours after treatment, haemoglobin values, and platelet and leucocyte counts were still lower than at baseline (P < 0.0001). The changes of haemoglobin, platelet and leucocyte values did not differ for citrate and heparin.

CONCLUSIONS

In patients with contraindications against heparin use, ACD-A citrate anticoagulation during photopheresis is a safe and efficient alternative. Photopheresis induces profound changes of the blood count, irrespective of the anticoagulation method.

Simplified citrate anticoagulation for high-flux hemodialysis

In a randomized crossover trial, we compared a simple citrate anticoagulation protocol for high-flux hemodialysis with standard anticoagulation by low-molecular-weight heparin (dalteparin). Primary end points were urea reduction rate (URR), Kt/V, and control of electrolyte and acid-base homeostasis. Secondary end points were bleeding time at vascular puncture sites and markers of activation of platelets, coagulation, and fibrinolysis. Solute removal during citrate dialysis was excellent (URR, 0.71 +/- 0.06; Kt/V, 1.55 +/- 0.3) and similar to results of conventional bicarbonate hemodialysis anticoagulation with dalteparin (URR, 0.72 +/- 0.04; Kt/V, 1.56 +/- 0.2). Electrolyte control was effective with both anticoagulation regimens, and total and ionized calcium, sodium, potassium, and phosphate concentrations at the end of dialysis did not differ. Alkalemia was less frequent after citrate than conventional dialysis (pH 7.5 in 25% versus 62% of patients; mean pH at end of dialysis, 7.46 +/- 0.06 versus 7.51 +/- 0.07; P < 0.01). Bleeding time at puncture sites was shorter by 30% after citrate compared with dalteparin anticoagulation (5.43 +/- 2.80 versus 7.86 +/- 2.93 minutes; P < 0.001). Activation of platelets, coagulation, and fibrinolysis was modest for both treatments and occurred mainly within the dialyzer during dalteparin treatment and in the vascular-access region during citrate anticoagulation. Citrate-related adverse events were not observed. We conclude that citrate anticoagulation for high-flux hemodialysis is feasible and safe using a simple infusion protocol.

Expanding our interventional skills: placement of totally implantable injection ports by internists/intensivists

Totally implantable injection ports are usually placed by surgeons or radiologists using fluoroscopic guidance. In a prospective study we evaluated the efficacy of percutaneous insertion of these devices without the use of fluoroscopic control by internists/intensivists experienced in the placement of permanent cuffed catheters. The supraclavicular approach to the subclavian vein was chosen for first line puncture site because of its low rate of malpositions and complications. 101 ports were inserted in 101 consecutive patients, 96 from the supraclavicular approach. Difficulties in introducing the catheter through the peel-away sheath, misplacement into adjacent vessels, secondary migration, or fragmentation of a line were not observed. Function was excellent in all ports. Three pneumothoraces (3%) and three arterial punctures (3%), none of which required intervention, were recorded. Two ports (2%) had to be revised, one due to local hematoma and another because of inadequate catheter length. Catheter survival was 94% in a 30-month observation period. Placement of totally implantable port systems by internists/intensivists experienced in placing central venous lines is safe and efficient, thus the implantation can easily be performed with minimal technical expenditure in the setting of an intensive care unit. The supraclavicular approach is suitable for insertion of permanent infusion port systems without fluoroscopic control.

Efficacy of folinic versus folic acid for the correction of hyperhomocysteinemia in hemodialysis patients

The effectiveness of intravenous folinic acid or intravenous folic acid for the treatment of hyperhomocysteinemia of hemodialysis patients is unknown. In a randomized, controlled, double-blind trial, 66 hemodialysis patients were administered either 15 mg of folic acid or an equimolar amount (16.1 mg) of folinic acid intravenously three times weekly. Normalization of total homocysteine (tHcy) plasma levels after 4 weeks of treatment was achieved in 10 patients (30.3%) in the folic-acid group and 6 patients (18.2%; P: = 0.389) in the folinic-acid group (normalization at any time during the study period in 39.4% and 33.3% of the patients; P: = 0.798). The relative reduction in tHcy plasma levels at week 4 was 32.2% in the folic-acid group and 34.1% in the folinic-acid group. A high baseline tHcy plasma concentration (P: = 0.00001), methylenetetrahydrofolate reductase (MTHFR) 677TT/1298AA genotype (P: = 0.03540), and low red blood cell folate concentrations (P: = 0.02285) were associated with a better relative response to treatment. Normalization of tHcy plasma levels was dependent on a lower baseline tHcy level (P: = 0.01976), younger age (P: = 0.00896), and MTHFR 677TT/1298AA or 677CT/1298AC genotypes (P: = 0.00208 and P: = 0.02320, respectively). A 4-week course of intravenous folinic acid is not superior to intravenous folic acid in reducing elevated tHcy plasma levels in hemodialysis patients. The response to treatment is predicted by tHcy plasma level, red blood cell folate content, and MTHFR genotype.

The shampoo clue: two cases of infection of a ventriculoatrial shunt

Despite the use of sophisticated tools, infections of implanted devices may be difficult to diagnose. Two cases of infections of ventriculoatrial shunts, which demonstrate the eminent importance of meticulously taking history, are reported and discussed.

Inadvertent transpericardial insertion of a central venous line with cardiac tamponade failure of preventive practices

A 56-year-old man who had undergone cardiac surgery suffered from cardiac tamponade after administration of contrast-medium through a central venous catheter. Pericardiotomy showed the catheter transversing the pericardial sac just beneath an unusual high reflection and then reentering the superior vena cava. Preventive practices including chest radiography, confirming free venous blood return and manometry may fail to detect catheter malposition in rare cases. Knowledge of potential pitfalls in using generally recommended safety practices and continuous vigilance are essential for the anesthesiologist and intensivist in avoiding potentially lethal hazards.

Safe and efficient emergency transvenous ventricular pacing via the right supraclavicular route

Infraclavicular and internal jugular central venous access are techniques commonly used for temporary transvenous pacing. However, the procedure still has a considerable complication rate, with a high risk/benefit ratio because of insertion difficulties and pacemaker malfunction. To enlarge the spectrum of alternative access sites, we prospectively evaluated the right supraclavicular route to the subclavian/innominate vein for emergency ventricular pacing with a transvenous flow-directed pacemaker as a bedside procedure. For 19 mo, 17 consecutive patients with symptomatic bradycardia, cardiac arrest, or torsade de pointes requiring immediate bedside transvenous pacing were enrolled in the study. The success rate, insertional complications, pacemaker performance, and patients' outcomes were recorded. Supraclavicular venipuncture was successful in all patients, in 16 of 17 at the first attempt. Adequate ventricular pacing was achieved within 1 to 5 min (median, 2 min) after venipuncture and within 10 s to 4 min (median, 30 s) after lead insertion (</=30 s in 15 of 17 patients). The median pacing threshold was 1 mA (range, 0.7 to 2.5 mA). No procedure-related complications were recorded. Throughout the pacing period of 1538 h (median: 62 h, range, 1-280 h) two reversible malfunctions caused by inadvertent lead dislodgement after 122 and 171 h were recorded; in one patient the pacemaker had to be removed because of local infection after 14 days of pacing. We conclude that the right supraclavicular route is an easy, safe, and effective first approach for transvenous ventricular pacing and might provide a useful alternative to traditional puncture sites, even in a preclinical setting.

IMPLICATIONS

Temporary transvenous cardiac pacing can yield high complication rates especially under emergency conditions. We investigated emergency pacing via the right supraclavicular access in 17 consecutive hemodynamically compromised patients and found good safety, efficacy, and a low complication rate.

Routine fluoroscopic guidance is not required for placement of Hickman catheters via the supraclavicular route

The purpose of this study was to evaluate the efficacy and safety in placement of Hickman catheters via the supraclavicular route without fluoroscopic guidance. We studied 81 consecutive percutaneous placements of dual lumen Hickman catheters via the supraclavicular route without the use of fluoroscopic guidance. Success rates, technical problems, complications, infections and reasons for explantation were recorded prospectively. Seventy-nine punctures were successful (97.5%). One pneumothorax (1.2%) and three accidental arterial punctures (3.7%) occurred. Difficulties in introducing the catheter through the peel away sheath or misplacement were not observed. The catheters remained in place for a total of 7657 days (mean 94.5, range 3-392 days). Sixteen blood cultures were positive (2.1/1000 catheter days). Five catheters (6.1%) were lost because of mechanical complications. Forty-two lines (52%) were removed electively, 23 (28.4%) because of suspected infection, and two (2.5%) because of tunnel infection. Nine patients died with a functioning catheter. We conclude that the supraclavicular approach to the subclavian vein is safe and efficient for introduction of Hickman catheters. Using this access, routine fluoroscopic or sonographic guidance is not required for proper placement. Implantation of the lines in an intensive care unit did not lead to higher infection rates than those reported in the literature.

Fat-soluble vitamins in patients with acute renal failure

OBJECTIVE

Systematic investigations on the status of fat-soluble vitamins in patients with acute renal failure (ARF) are lacking and hence no recommendations for vitamin supply can be defined for these subjects. Thus we compared the status of fat-soluble vitamins, of transport molecules and some vitamin-dependent proteins in patients with ARF and healthy controls.

SETTING

Nephrology unit of a university hospital.

PATIENTS AND METHODS

Eight patients with ARF requiring hemodialysis therapy were investigated and 28 healthy volunteers served as controls. Plasma concentrations of retinol (vitamin A) and retinol-binding protein (RBP), 25-OH and 1,25-(OH)2 vitamin D3, of parathyroid hormone (PTH), of alpha-tocopherol (vitamin E) and of phylloquinone (vitamin K), osteocalcin and noncarboxylated osteocalcin, respectively, were measured and plasma lipoprotein fractions (as vitamin transport vehicle) were evaluated.

RESULTS

Vitamin A levels were decreased (p < 0.001), but RBP levels were normal in ARF patients. Vitamin D3 metabolites 25-OH and 1,25-(OH)2 vitamin D3 plasma levels were profoundly depressed, and PTH was elevated (p < 0.001). Vitamin E plasma concentration was reduced (p < 0.001) but this cannot be accounted for by decreased LDL cholesterol or triglyceride levels. In contrast, vitamin K plasma level was rather elevated in ARF patients with a broad range of individual values. Blood coagulation was normal but total and carboxylated osteocalcin were decreased. No correlation of vitamin K concentrations and any of the plasma lipoprotein fractions could be identified.

CONCLUSION

With the exception of vitamin K, profound deficiencies of fat-soluble vitamins develop in patients with ARF. Current recommendations for vitamin supplementation are inadequate and should be reevaluated for these patients.

Supraclavicular approach to the subclavian/innominate vein for large-bore central venous catheters

Infraclavicular and internal jugular catheterization are commonly used techniques for hemodialysis access, but may at times be impeded in patients whose anatomy makes cannulation difficult. In an effort to enlarge the spectrum of alternative access sites, we evaluated the supraclavicular approach for large-bore catheters. During an 18-month period we prospectively collected data on success rate and major and minor complications of the supraclavicular access for conventional dialysis catheters as well as Dacron-cuffed tunneled devices in 175 adult patients admitted for various extracorporeal therapies and bone marrow transplantation. Two hundred eight large-bore catheters (99 conventional dialysis catheters, 63 semirigid tunneled Dacron-cuffed catheters, and 46 Hickman catheters) were successfully placed in 164 patients (success rate, 93.8%), 58 (33.1%) of whom had been previously catheterized. Complications included pneumothorax (one patient), arterial puncture (seven patients), and puncture of the thoracic duct (two patients) without sequelae. Postinsertional chest radiographs demonstrated impressive coaxial lie of most catheters. Catheter malpositions occurred only sporadically (1%). Difficulty of introducing the catheter via a placed sheath was rarely observed. There was no clinically significant evidence of catheter-induced venous thrombosis or stenosis. We conclude that the supraclavicular route is an easy and safe first approach for large-bore catheters, as well as a useful alternative to traditional puncture sites for precatheterized and anatomically problematic patients.

Cyclosporin A-induced ocular flutter after marrow transplantation

Ocular flutter is a rare neurologic condition occurring in patients suffering from viral encephalitis, intracranial neoplasia, paraneoplastic syndrome or intoxications. Neurotoxicity is a recognized complication of cyclosporin A (CsA) therapy, but ocular flutter has not been reported in association with CsA administration to date. We describe a 17-year-old female patient who developed ocular flutter 51 days after transplantation with marrow from an unrelated donor, for acute myeloid leukemia. After discontinuation of cyclosporin, which was given for prophylaxis of graft-versus-host disease, the clinical symptoms resolved within 3 weeks, but a slightly abnormal electrooculogram persisted for more than 10 months.

Malposition of central venous catheters. Incidence, management and preventive practices

INTRODUCTION

Proper placement is an essential prerequisite for the use of central venous catheters. Our study was undertaken to determine the incidence of aberrant locations dependent on different anatomic approaches for various types of central venous catheters and to elucidate failures and pitfalls of preventive practices.

METHODS

2580 percutaneously inserted lines (including 538 tunneled devices and 112 implantable Port-A-Caths) introduced by Seldinger's technique were reviewed for inadvertent malpositioning.

RESULTS

Primary misplacement was evident on 47 occasions (1.82%), 38 times into large venous tributaries of the superior vena cava. 3 aberrant locations involved a persistent left superior vena cava, two catheters were placed into minor intrathoracic veins and in 3 patients inadvertent arterial cannulation occurred. The frequency of malpositioning was related to the anatomic approach and the catheter type used, but not to the physician's experience. Respective incidences were 4.12% for the left internal jugular access, but were lower for the right internal jugular (1.1%) and the right (1.01%) and left (0.89%) supraclavicular approach. Misplacement was more frequent with soft silicone catheters (2.53%) than with semi-rigid catheters (0.79%). All malpositions but one were detected on chest X-ray.

DISCUSSION

Our data suggest that the incidence of catheter malposition depends on the site of insertion, the type of material used, but not on the experience of the physician who inserted the catheter. Scrupulous use of preventive practices reduces the frequency of malpositioned catheters, but physicians must keep in mind potential pitfalls. Injection of radioopaque contrast medium into the catheter during control chest X-ray should be done even with opaque catheters.

Impairment of citrate metabolism in acute hepatic failure

AIMS

To compare the utilization of citrate employed as anticoagulant in patients with acute hepatic failure and subjects with normal liver function.

PATIENTS AND METHODS

Three patients in acute hepatic failure and normal renal function were studied during therapeutic plasma exchange with citrate containing fresh frozen plasma. Six patients receiving immunapheresis or LDL-apheresis anticoagulated with citrate served as controls. Determinations of serum citrate concentrations, of ionized calcium and blood pH were performed before, during, and after the extracorporeal treatment. Total body clearance and elimination half life were calculated in a two compartment model.

RESULTS

Preinfusion citrate levels were higher in the patients with acute hepatic failure than in the controls (n.s.). The citrate level rose to 1.73 +/- 0.2 mmol/l in the liver patients versus 0.99 +/- 0.1 mmol/l in the healthy subjects (p < 0.03). Total body clearance was markedly reduced in patients with acute hepatic failure (3.31 +/- 0.03 ml/kg/min) as compared with the controls (6.34 +/- 0.16 ml/kg/min) (p < 0.02), the elimination half life (t/2 k1e) was prolonged (49.7 +/- 5.4 vs. 32.9 +/- 1.02 min, p < 0.05). In the controls blood pH rose from 7.4 +/- 0.01 to 7.45 +/- 0.01 (p < 0.05) after citrate infusion, whereas in the liver patients no rise in pH was observed, again reflecting the impairment of citrate metabolism. Ionized calcium was lower in the patients with acute hepatic failure at the beginning (1.01 +/- 0.05 vs. 1.21 +/- 0.04 mmol/l, p < 0.05) and the end (0.68 +/- 0.02 vs. 0.93 +/- 0.04 mmol/l, p < 0.05) of the citrate infusion.

CONCLUSIONS

Citrate metabolism is severely impaired and the plasmatic calcium stores are reduced in acute hepatic failure and, thus, the risk of adverse effects is high. Therapeutic infusions of citrate should be restricted in patients with acute hepatic failure and, if necessary, therapy should be closely monitored by repeated measurements of ionized calcium to avoid the development of potentially hazardous hypocalcemia.

Percutaneous nonangiographic insertion of Hickman catheters in marrow transplant recipients by anesthesiologists and intensivists

Long-term central venous lines for chronic hemoaccess are usually inserted in the operating theater under local or general anesthesia or in interventional radiology suites using fluoroscopic technique. In a prospective study we determined the feasibility of percutaneous insertion of Hickman catheters without fluoroscopic control by anesthesiologists and intensivists in the setting of an intensive care unit. Fifty-four Hickman catheters were placed in 53 consecutive patients with hematological disorders and/or neoplastic diseases undergoing allogeneic or autologous bone marrow transplantation (BMT) or buffy coat therapy. There were no major complications. The mean time for insertion was 35 min. The median life span of catheters was 70 days (range 3-214). Twenty-six catheters were electively removed; six remained functioning in situ at the end of the study. For 3333 catheter days (1471 days in hospital and 1862 days at domiciliary care), six catheters were removed because of mechanical complications (inadvertent dislodgement, leak, secondary migration) and 14 because of suspected or documented infection. We conclude that percutaneous nonangiographic insertion of Hickman catheters by anesthesiologists minimizes technical expenditure and is at least as effective as surgical or radiological techniques. The rate of clinically important complications is acceptable.

Alternative puncture site for implantable permanent haemodialysis catheters

BACKGROUND

Vascular access represents a major problem in long-term haemodialysis patients. In patients without patent internal arteriovenous fistula, the implantation of cuffed catheters to provide a temporary or permanent central venous access is often necessary. Catheterization of the subclavian vein should be avoided because of the high risk of stenosis or thrombosis. The puncture of the internal jugular vein can be impossible in cases with stenosis or thrombosis due to previous catheterization. To overcome these limitations we evaluated an alternative puncture site for implantation of permanent central venous catheters.

METHODS

The very low, most central jugular approach, first described by Rao et al., with the site of puncture just above the medial notch of the clavicle, was used to introduce Dacron cuffed dialysis catheters into the innominate vein in four chronic dialysis patients with impeded conventional vascular access.

RESULTS

In all four patients puncture of the internal jugular vein using Rao's technique was successful at the first attempt. All four catheters were introduced without any problems. Even in a case with thrombosis of the internal jugular vein and the ipsilateral subclavian vein, this technique was successfully applied. No complications such as haematoma, pneumothorax, or catheter-associated infection were observed. The catheters remained in situ for 2-12 months with excellent blood flow and without clinical evidence of venous stenosis or thrombosis.

CONCLUSIONS

In case of failure to cannulate the internal jugular vein by a conventional approach, the technique of Rao et al. can be used before sacrificing the subclavian vein or changing to exotic techniques such as translumbar, transfemoral or transhepatic methods.

Gastric mucormycosis due to Rhizopus oryzae in a renal transplant recipient

Gastric mucormycosis is a rare disease with a reported fatal outcome of 98%. Manifestations range from colonization of peptic ulcers to infiltrative disease with vascular invasion and dissemination. In our renal transplant patient a deep gastric ulceration infected with Rhizopus oryzae (class Zygomycetes), which is known to be an agent of mucormycosis, was diagnosed in the early posttransplant period after antirejection therapy. The infection was successfully managed with amphotericin B and omeprazole.