Per Jonsson

Microemboli, developed during haemodialysis, pass the lung barrier and may cause ischaemic lesions in organs such as the brain

BACKGROUNDnChronic haemodialysis (HD) may relieve some medical problems of terminal uraemia, but the life expectancy of patients is still significantly shortened, and there is a greatly increased morbidity. This includes pulmonary morbidity and chronic central nervous system (CNS) abnormalities. Previous studies have shown that a considerable amount of air microbubbles emanate within the blood lines of the dialysis device and pass the air detector without sounding an alarm. The aim of this study was to investigate whether microemboli can pass to the patient and whether they could be detected in the carotid artery.nnnMETHODSnA total of 54 patients on chronic HD (16 with central dialysis catheter) were investigated with an ultrasound detector (Hatteland, Røyken, Norway) for the presence of microemboli at the arteriovenous (AV) fistula/graft and at the common carotid artery before and during HD. Measurements were taken for 2 and 5 min, respectively. Non-parametric paired statistics were used (Wilcoxon).nnnRESULTSnThe median number (range) and mean +/- SD of microembolic signals detected at the AV access site before commencing dialysis and during HD were 0 (0-3) and 0.2+/- 0.5 versus 4 (0-85) and 13.5 +/- 20 (P = 0.000); at the carotid artery, 1 (0-14) and 1.7 +/- 2.9 versus 2 (0-36) and 3.5 +/- 5.8 (P = 0.008).nnnCONCLUSIONSnThe infused and returning fluid from HD devices contains air microbubbles that enter the patient without triggering any alarms. These small emboli pass the lung and may cause ischaemic lesions in organs supported by the arterial circuit, such as the brain.

A significant proportion of patients treated with citrate containing dialysate need additional anticoagulation

Background The blood membrane interaction induced during hemodialysis (HD) activates the coagulation system. To prevent clotting and to maintain dialyzer patency, an anticoagulant such as tinzaparin is used. To increase patency of the dialyzers and to reduce the risk of bleeding related to anticoagulation, citrate-containing dialysate has been introduced in Europe. Purpose The aim of this randomized, cross-over study was to investigate if citrate-containing dialysate was safe and efficient enough as the sole anticoagulation agent in chronic HD patients. Material and Methods In this clinical setting, 23 patients on chronic hemodialysis were randomized in a cross-over design using anticoagulation either by LMWH-tinzaparin or citrate (Cit) as dialysate (22 completed the study). The study included paired analyses of subjective patency, ionized calcium (iCa), urea reduction rate. During Cit-HD, the iCa was significantly more reduced with prolonged time. The lowest iCa measured was 0.96 mmol/l. The median iCa after 210 min of HD was 1.02 for Cit-Hd and 1.16 for standard tinzaparin-HD (p = 0.001). Patency of dialyzers was estimated as clear in 14%, stripes of clotted fibers in 36%, and a red filter in 32% of HD session. The addition of approximately 40% of the patients’ usual dose of tinzaparin was given to 7 of the patients as a bolus. Four Cit-HD sessions had to be interrupted prematurely due to clotting. Conclusion A significant proportion of patients treated with citrate-containing dialysate need additional anticoagulation.

A High Blood Level in the Air Trap Reduces Microemboli During Hemodialysis

Previous studies have demonstrated the presence of air microemboli in the dialysis circuit and in the venous circulation of the patients during hemodialysis. In vitro studies indicate that a high blood level in the venous air trap reduces the extent of microbubble formation. The purpose of this study was to examine whether air microbubbles can be detected in the patients access and if so, whether the degree of microbubble formation can be altered by changing the blood level in the venous air trap. This was a randomized, double-blinded, interventional study of 20 chronic hemodialysis patients. The patients were assigned to hemodialysis with either an elevated or a low blood level in the air trap. The investigator and the patient were blinded to the settings. The numbers of microbubbles were measured at the site of the arteriovenous (AV) access for 2u2003min with the aid of an ultrasonic Doppler device. The blood level in the air trap was then altered to the opposite setting and a new measurement was carried out after an equilibration period of 30u2003min. Median (range) for the number of microbubbles measured with the high air trap level and the low air trap level in AV access was 2.5 (0-80) compared with 17.5 (0-77), respectively (Pu2003=u20030.044). The degree of microbubble formation in hemodialysis patients with AV access was reduced significantly if the blood level in the air trap was kept high. The exposure of potentially harmful air microbubbles was thereby significantly reduced. This measure can be performed with no additional healthcare cost.

Blood lines conduct leakage current during haemodialysis: a potential safety risk during first failure, especially for patients with central dialysis catheter as access

Haemodialysis (HD) machines are IEC-classified as I type B. When central dialysis catheters (CDCs) are used for access, there will be close electrical contact with the heart. To investigate the risk for HD patients, the leakage of current through the tubing set was measured during in vitro dialysis performed according to the IEC 60601-1 standard for class I cardiac floating (CF) devices. A series of eight measurements were made with Gambro GFS+12 dialysers, first with saline and then with blood in the blood lines. The leakage current exceeded the CF limit (50 μA) at the top of the CDC using the test ‘mains on applied part’ for saline (median 1008 μA, range 720–1241 μA), for blood (median 610 μA, range 449–772μA) and also for a ‘single fault condition’ using saline (median 68 μA, range 35–118 μA) or blood (47 μA, range 4–128 μA). In the single fault condition, the highest leakage current at the CDC (128 μA) almost exceeded the earth leakage current in normal conditions. A safety risk can appear if a single fault arises in the dialysis machine or another device connected to the same patient, or during ‘mains contact to the patient’. Then the current flow may be high enough to induce arrhythmias in the patient, especially when a CDC is used. These data and the use of CDCs as access for dialysis indicate that HD machines should be classified as cardiac floating rather than body (B) devices.

A high blood level in the venous chamber and a wet-stored dialyzer help to reduce exposure for microemboli during hemodialysis

During hemodialysis (HD), microemboli develop in the blood circuit of the apparatus. These microemboli can pass through the venous chamber and enter into the patients circulation. The aim of this study was to investigate whether it is possible to reduce the risk for exposure of microemboli by altering of the treatment mode. Twenty patients on chronic HD were randomized to a prospective cross‐over study of three modes of HD: (a) a dry‐stored dialyzer (F8HPS, Fresenius, steam sterilized) with a low blood level in the venous chamber (DL), (b) the same dialyzer as above, but with a high level in the venous chamber (DH), and (c) a wet‐stored dialyzer (Rexeed, Asahi Kasei Medical, gamma sterilized) with a high blood level (WH). Microemboli measurements were obtained in a continuous fashion during 180 minutes of HD for all settings. A greater number of microemboli were detected during dialysis with the setting DL vs. WH (odds ratio [OR] 4.07, 95% confidence interval [CI] 4.03–4.11, Pu2009<u20090.0001) and DH vs. WH (OR 1.18, 95% CI 1.17–1.19, Pu2009<u20090.0001) and less for DH vs. DL (OR 0.290, 95% CI 0.288–0.293, Pu2009<u20090.0001). These data indicate that emboli exposure was least when using WH, greater with DH, and most with DL. This study shows that using a high blood level in the venous chamber and wet‐stored dialyzers may reduce the number of microemboli.

Formation of Blood Foam in the Air Trap During Hemodialysis Due to Insufficient Automatic Priming of Dialyzers

We were encouraged to investigate the reasons for large amounts of foam observed in bloodlines during hemodialysis (HD). Foam was visible in the venous air trap within the Artis Gambro dialysis device. Estimates of the extent of foam were graded (0-no foam, 10-extensive foam) by two persons that were blind to the type of dialyzer used. Thirty-seven patients were involved in the dialysis procedures. Consecutive dialyses were graded using dialyzers from Fresenius Medical Care (CorDiax dialyzers that were used for high flux HD-FX80 and FX100, and for hemodiafiltration-FX1000). The extracorporeal circuit was primed automatically by dialysate using Gambro Artis software 8.15 006 (Gambro, Dasco, Medolla Italy, Baxter, Chicago, IL, USA). The priming volume recommended by the manufacturer was 1100 mL, whereas our center uses 1500 mL. Extensive amounts of blood foam were visual in the air traps. Although the manufacturer recommended extension of priming volume up to 3000 mL, this did not eliminate the foam. Microbubble measurement during HD revealed the air to derive from the dialyzers. When changing to PF210H dialyzers (Baxter) and using a priming volume of 1500 mL, the foam was significantly less (Pu2009<u20090.01). The extent of foam correlated with the size of the FX-dialyzer surface (Pu2009=u20090.002). The auto-priming program was updated to version 8.21 by the manufacturer and the extent of foam in the air trap using FX dialyzers was now reduced and there was no longer a difference between FX and PF dialyzers, although less foam was still visible in the venous air trap during several dialyses. In conclusion, this study urgently calls attention to blood foam development in the venous air trap when using Artis devices and priming software 8.15 in combination with Fresenius dialyzers. Updated auto-priming software (version 8.21) of Artis should be requested to reduce the extent of foam for the Fresenius dialyzers. Other interactions may also be present. We recommend further studies to clarify these problems. Meanwhile caution is warranted for the combined use of dialysis devices and dialyzers with incompatible automatic priming.

A microscopic view of gaseous microbubbles passing a filter screen

Purpose The aim of this study was to investigate the filtration efficacy of a 38-μm 1-layer screen filter based on Doppler registrations and video recordings of gaseous microbubbles (GME) observed in a microscope. Methods: The relative filtration efficacy (RFE) was calculated from 20 (n = 20) sequential bursts of air introduced into the Plasmodex® primed test circuit. Results The main findings indicate that the RFE decreased (p = 0.00), with increasing flow rates (100–300 mL/ min) through the filter screen. This reaction was most accentuated for GME below the size of 100 μm, where counts of GME paradoxically increased after filtration, indicating GME fragmentation. For GME sized between 100–250 μm, the RFE was constantly >60%, independently of the flow rate level. The video recording documenting the GME interactions with the screen filter confirmed the experimental findings. Conclusions The 38-μm 1-layer screen filter investigated in this experimental setup was unable to trap gaseous microbubbles effectively, especially for GME below 100 μm in size and in conjunction with high flow rates.

Evaluation of air contamination incidences and in vitro settings and experiences of micro bubbles

Evaluation of air contamination incidences and in vitro settings and experiences of micro bubblesThe use of citrate-containing dialysate for anticoagulation in hemodialysis (hd). report of clinical experienceK1 (EI0154) AGES IN HEMODIALYSIS: TISSUEAND PLASMAAUTOFLUORESCENCE R. Graaff1, S. Arsov1, L. Trajceska4, P. Dzekova4, G.E. Engels1, M. Koetsier1, W. van Oeveren1, L Lundberg5, S. Assa2, C.F.M. Franssen2, A.J. Smit3, G. Rakhorst1, A. Sikole2, B. Stegmayr5 1Dept. of Biomedical Engineering, 2Internal Medicine, Div. Nephrology and 3Div. Vascular Medicine, University Medical Center Groningen, Groningen, The Netherlands; 4Department of Nephrology, University Clinic of Nephrology, Skopje, R. Macedonia; 5Department of Internal Medicine, University Hospital, Umea, SwedenObjectives: During HD previous studies have shown that especially micro bubbles of air may pass the air detector. These studies focused to analyse in vitro if the air trap of various producers may ...Artificial Kidney – Uremic Toxins – SYMPOSIUM, 606 Smart and Responsive Biomaterials – SYMPOSIUM, 607 Cardiovascular General 1: Devices – GENERAL SESSION, 608 Ambulatory Blood Processing – SYMPOSIUM, 610 Animal Models for Tissue Engineering – SYMPOSIUM, 610 Cardiovascular General 2: Devices Interaction – GENERAL SESSION, 612 Artificial Muscle for Internal Organ – SYMPOSIUM, 613 Functionalized Biomaterials – SYMPOSIUM, 614 Cardiovascular General 3: Physiology and Pump Control – GENERAL SESSION, 615 Vascular Access in Hemodialysis – SYMPOSIUM, 617 Polymeric Membranes/Blood Interfaces – SYMPOSIUM, 618 Nano and Micro Technology: Driving the Future of Organ Recovery & Development – SYMPOSIUM, 619 Roadbumps for Tissue-Engineering Artificial Organs – SYMPOSIUM, 621 Artificial Liver GENERAL SESSION, 621 Tissue Engineering Approaches – SYMPOSIUM, 622 Cardiovascular General 4: Cardiopulmonary – GENERAL SESSION, 624 Artificial Kidney Dialysis – SYMPOSIUM, 625 Tissue Engineering of Skin: Creating a New Bio-Artificial Organ for Clinical Application – SYMPOSIUM, 627 Cardiovascular General 5: Device & Biology – GENERAL SESSION, 628 Citrate Anticoagulation A Future Option for Extracorporeal Blood Purification – SYMPOSIUM, 629 Latest Advances in Preventive and Regenerative Medicine Technologies – SYMPOSIUM, 630 Intra-Aortic Balloon Pump as a Cardiac Assist Device – SYMPOSIUM, 631 Artificial Organ Transplantation – SYMPOSIUM, 632 New Biomaterials and Scaffolds – SYMPOSIUM, 633 Modelling of Cardiovascular and Pulmonary Function in Regard to Clinical Applications – SYMPOSIUM, 634 Artificial Kidney Dialysis Techniques – SYMPOSIUM, 635 Natural Based Polymeric Biomaterials and Composites for Regenerative Medicine – SYMPOSIUM, 637 Partial Cardiac Support in Shortand Long-Term Application – SYMPOSIUM, 638 Artificial Organs – Practical Applications – GENERAL SESSION, 639 Non-Destructive Techniques to Monitor 3D In Vitro Tissue Engineering Constructs – SYMPOSIUM, 640 Stent and Vascular Prosthesis – GENERAL SESSION, 641 Dialysis Techniques Access – GENERAL SESSION, 643 Scaffolds for TE Via Electrospinning-Structures and Biomaterials – SYMPOSIUM, 644 Drug Delivery Systems – GENERAL SESSION, 646 “Approval Procedures for Medical Devices: Facts, Figures and Basic Rules Seen from Different Continental Perspectives – Artificial Organs and Society: Recent Trends in Japan”, 647K1 (EI0154) AGES IN HEMODIALYSIS: TISSUEAND PLASMAAUTOFLUORESCENCE R. Graaff1, S. Arsov1, L. Trajceska4, P. Dzekova4, G.E. Engels1, M. Koetsier1, W. van Oeveren1, L Lundberg5, S. Assa2, C.F.M. Franssen2, A.J. Smit3, G. Rakhorst1, A. Sikole2, B. Stegmayr5 1Dept. of Biomedical Engineering, 2Internal Medicine, Div. Nephrology and 3Div. Vascular Medicine, University Medical Center Groningen, Groningen, The Netherlands; 4Department of Nephrology, University Clinic of Nephrology, Skopje, R. Macedonia; 5Department of Internal Medicine, University Hospital, Umeå, SwedenDoes the advanced glycation end-products (ages) food intake influence mortality in dialysis patients?

In vitro testing of prevailing materials and initial clinical findings

Evaluation of air contamination incidences and in vitro settings and experiences of micro bubblesThe use of citrate-containing dialysate for anticoagulation in hemodialysis (hd). report of clinical experienceK1 (EI0154) AGES IN HEMODIALYSIS: TISSUEAND PLASMAAUTOFLUORESCENCE R. Graaff1, S. Arsov1, L. Trajceska4, P. Dzekova4, G.E. Engels1, M. Koetsier1, W. van Oeveren1, L Lundberg5, S. Assa2, C.F.M. Franssen2, A.J. Smit3, G. Rakhorst1, A. Sikole2, B. Stegmayr5 1Dept. of Biomedical Engineering, 2Internal Medicine, Div. Nephrology and 3Div. Vascular Medicine, University Medical Center Groningen, Groningen, The Netherlands; 4Department of Nephrology, University Clinic of Nephrology, Skopje, R. Macedonia; 5Department of Internal Medicine, University Hospital, Umea, SwedenObjectives: During HD previous studies have shown that especially micro bubbles of air may pass the air detector. These studies focused to analyse in vitro if the air trap of various producers may ...Artificial Kidney – Uremic Toxins – SYMPOSIUM, 606 Smart and Responsive Biomaterials – SYMPOSIUM, 607 Cardiovascular General 1: Devices – GENERAL SESSION, 608 Ambulatory Blood Processing – SYMPOSIUM, 610 Animal Models for Tissue Engineering – SYMPOSIUM, 610 Cardiovascular General 2: Devices Interaction – GENERAL SESSION, 612 Artificial Muscle for Internal Organ – SYMPOSIUM, 613 Functionalized Biomaterials – SYMPOSIUM, 614 Cardiovascular General 3: Physiology and Pump Control – GENERAL SESSION, 615 Vascular Access in Hemodialysis – SYMPOSIUM, 617 Polymeric Membranes/Blood Interfaces – SYMPOSIUM, 618 Nano and Micro Technology: Driving the Future of Organ Recovery & Development – SYMPOSIUM, 619 Roadbumps for Tissue-Engineering Artificial Organs – SYMPOSIUM, 621 Artificial Liver GENERAL SESSION, 621 Tissue Engineering Approaches – SYMPOSIUM, 622 Cardiovascular General 4: Cardiopulmonary – GENERAL SESSION, 624 Artificial Kidney Dialysis – SYMPOSIUM, 625 Tissue Engineering of Skin: Creating a New Bio-Artificial Organ for Clinical Application – SYMPOSIUM, 627 Cardiovascular General 5: Device & Biology – GENERAL SESSION, 628 Citrate Anticoagulation A Future Option for Extracorporeal Blood Purification – SYMPOSIUM, 629 Latest Advances in Preventive and Regenerative Medicine Technologies – SYMPOSIUM, 630 Intra-Aortic Balloon Pump as a Cardiac Assist Device – SYMPOSIUM, 631 Artificial Organ Transplantation – SYMPOSIUM, 632 New Biomaterials and Scaffolds – SYMPOSIUM, 633 Modelling of Cardiovascular and Pulmonary Function in Regard to Clinical Applications – SYMPOSIUM, 634 Artificial Kidney Dialysis Techniques – SYMPOSIUM, 635 Natural Based Polymeric Biomaterials and Composites for Regenerative Medicine – SYMPOSIUM, 637 Partial Cardiac Support in Shortand Long-Term Application – SYMPOSIUM, 638 Artificial Organs – Practical Applications – GENERAL SESSION, 639 Non-Destructive Techniques to Monitor 3D In Vitro Tissue Engineering Constructs – SYMPOSIUM, 640 Stent and Vascular Prosthesis – GENERAL SESSION, 641 Dialysis Techniques Access – GENERAL SESSION, 643 Scaffolds for TE Via Electrospinning-Structures and Biomaterials – SYMPOSIUM, 644 Drug Delivery Systems – GENERAL SESSION, 646 “Approval Procedures for Medical Devices: Facts, Figures and Basic Rules Seen from Different Continental Perspectives – Artificial Organs and Society: Recent Trends in Japan”, 647K1 (EI0154) AGES IN HEMODIALYSIS: TISSUEAND PLASMAAUTOFLUORESCENCE R. Graaff1, S. Arsov1, L. Trajceska4, P. Dzekova4, G.E. Engels1, M. Koetsier1, W. van Oeveren1, L Lundberg5, S. Assa2, C.F.M. Franssen2, A.J. Smit3, G. Rakhorst1, A. Sikole2, B. Stegmayr5 1Dept. of Biomedical Engineering, 2Internal Medicine, Div. Nephrology and 3Div. Vascular Medicine, University Medical Center Groningen, Groningen, The Netherlands; 4Department of Nephrology, University Clinic of Nephrology, Skopje, R. Macedonia; 5Department of Internal Medicine, University Hospital, Umeå, SwedenDoes the advanced glycation end-products (ages) food intake influence mortality in dialysis patients?

Micro embolies of air are deposited in the organs in hemodialysis patients : a case report

Evaluation of air contamination incidences and in vitro settings and experiences of micro bubblesThe use of citrate-containing dialysate for anticoagulation in hemodialysis (hd). report of clinical experienceK1 (EI0154) AGES IN HEMODIALYSIS: TISSUEAND PLASMAAUTOFLUORESCENCE R. Graaff1, S. Arsov1, L. Trajceska4, P. Dzekova4, G.E. Engels1, M. Koetsier1, W. van Oeveren1, L Lundberg5, S. Assa2, C.F.M. Franssen2, A.J. Smit3, G. Rakhorst1, A. Sikole2, B. Stegmayr5 1Dept. of Biomedical Engineering, 2Internal Medicine, Div. Nephrology and 3Div. Vascular Medicine, University Medical Center Groningen, Groningen, The Netherlands; 4Department of Nephrology, University Clinic of Nephrology, Skopje, R. Macedonia; 5Department of Internal Medicine, University Hospital, Umea, SwedenObjectives: During HD previous studies have shown that especially micro bubbles of air may pass the air detector. These studies focused to analyse in vitro if the air trap of various producers may ...Artificial Kidney – Uremic Toxins – SYMPOSIUM, 606 Smart and Responsive Biomaterials – SYMPOSIUM, 607 Cardiovascular General 1: Devices – GENERAL SESSION, 608 Ambulatory Blood Processing – SYMPOSIUM, 610 Animal Models for Tissue Engineering – SYMPOSIUM, 610 Cardiovascular General 2: Devices Interaction – GENERAL SESSION, 612 Artificial Muscle for Internal Organ – SYMPOSIUM, 613 Functionalized Biomaterials – SYMPOSIUM, 614 Cardiovascular General 3: Physiology and Pump Control – GENERAL SESSION, 615 Vascular Access in Hemodialysis – SYMPOSIUM, 617 Polymeric Membranes/Blood Interfaces – SYMPOSIUM, 618 Nano and Micro Technology: Driving the Future of Organ Recovery & Development – SYMPOSIUM, 619 Roadbumps for Tissue-Engineering Artificial Organs – SYMPOSIUM, 621 Artificial Liver GENERAL SESSION, 621 Tissue Engineering Approaches – SYMPOSIUM, 622 Cardiovascular General 4: Cardiopulmonary – GENERAL SESSION, 624 Artificial Kidney Dialysis – SYMPOSIUM, 625 Tissue Engineering of Skin: Creating a New Bio-Artificial Organ for Clinical Application – SYMPOSIUM, 627 Cardiovascular General 5: Device & Biology – GENERAL SESSION, 628 Citrate Anticoagulation A Future Option for Extracorporeal Blood Purification – SYMPOSIUM, 629 Latest Advances in Preventive and Regenerative Medicine Technologies – SYMPOSIUM, 630 Intra-Aortic Balloon Pump as a Cardiac Assist Device – SYMPOSIUM, 631 Artificial Organ Transplantation – SYMPOSIUM, 632 New Biomaterials and Scaffolds – SYMPOSIUM, 633 Modelling of Cardiovascular and Pulmonary Function in Regard to Clinical Applications – SYMPOSIUM, 634 Artificial Kidney Dialysis Techniques – SYMPOSIUM, 635 Natural Based Polymeric Biomaterials and Composites for Regenerative Medicine – SYMPOSIUM, 637 Partial Cardiac Support in Shortand Long-Term Application – SYMPOSIUM, 638 Artificial Organs – Practical Applications – GENERAL SESSION, 639 Non-Destructive Techniques to Monitor 3D In Vitro Tissue Engineering Constructs – SYMPOSIUM, 640 Stent and Vascular Prosthesis – GENERAL SESSION, 641 Dialysis Techniques Access – GENERAL SESSION, 643 Scaffolds for TE Via Electrospinning-Structures and Biomaterials – SYMPOSIUM, 644 Drug Delivery Systems – GENERAL SESSION, 646 “Approval Procedures for Medical Devices: Facts, Figures and Basic Rules Seen from Different Continental Perspectives – Artificial Organs and Society: Recent Trends in Japan”, 647K1 (EI0154) AGES IN HEMODIALYSIS: TISSUEAND PLASMAAUTOFLUORESCENCE R. Graaff1, S. Arsov1, L. Trajceska4, P. Dzekova4, G.E. Engels1, M. Koetsier1, W. van Oeveren1, L Lundberg5, S. Assa2, C.F.M. Franssen2, A.J. Smit3, G. Rakhorst1, A. Sikole2, B. Stegmayr5 1Dept. of Biomedical Engineering, 2Internal Medicine, Div. Nephrology and 3Div. Vascular Medicine, University Medical Center Groningen, Groningen, The Netherlands; 4Department of Nephrology, University Clinic of Nephrology, Skopje, R. Macedonia; 5Department of Internal Medicine, University Hospital, Umeå, SwedenDoes the advanced glycation end-products (ages) food intake influence mortality in dialysis patients?