Vascular Access Recirculation in Hemodialysis Patients With Two Noncuffed, Single-lumen, Jugular Catheters in the Same Jugular Vein

Effects of the tip structure of temporary indwelling catheters on blood recirculation at various blood flow rates and diameters of the mock blood vessel

AIMS

The aim of the present study was to determine the effects of the tip structure of the catheters used for hemodialysis on blood recirculation at varying blood flow rates and diameters of the mock blood vessel in a well-defined in vitro experimental system, focusing on reverse connection mode.

METHODS

A mock circulatory circuit was created with silicon tubing (15 or 20 mm), a circulatory pump, connected through the catheter to dialysis circuit and dialyzer attached to dialysis machine. The tip of the inserted catheter was fixed to the center of the silicone tube, and 3 L of pig blood was poured into the blood side of the dialyzer and the recirculation rates were measured at blood flow rates of 100, 150, and 200 mL/min. Five types of commercially available catheters were used: (A) Argyle™, (B) Gentle Cath™ (Hardness gradient type), (C) Gentle Cath™, (D) Niagara™, and (E) Power-Trialysis®.

RESULTS

In the case of reverse connection mode, (1) the recirculation rates were lower in the catheter with a relatively large side hole (catheter C, 17%), catheters with a greater distance between the end hole and side hole (catheters C and D, 25%), and catheter with a symmetrical tip structure (catheter E, 10%) as compared with those in catheters A and B (40% and 25%); (2) increase of the blood flow rate in the dialysis machine was associated with a reduced recirculation rate; and (3) a wider inner diameter of the mock blood vessel and faster flow rate in the vessel were associated with a reduced recirculation rate.

CONCLUSION

The lowest recirculation was observed with the catheter with symmetrical holes, which produces a helical blood flow line that does not intersect with the blood streamline flowing out to the blood supply hole.

Temporary Catheters as a Permanent Vascular Access in Very Elderly Hemodialysis Patients: Frequency of Complications and Interventions

The choice of vascular access in very elderly hemodialysis patients can be complex. Data on the frequency of interventions and complications when temporary catheters are used for long periods in this population are lacking. All incident patients ≥80 years old, dialyzed over non-tunneled catheters, were included and the frequency of interventions (re-insertions and wire-exchanges) and complications (catheter-related blood stream infections) were recorded. In 31 patients aged 84 ± 4 years, dialyzed for 1.4 ± 1.1 years, 87 interventions were needed (2.02/patient-year). The median time to first intervention was 5.5 months and the 1-year intervention-free rate was 32%. There were three catheter-related blood stream infections (0.2/1000 access-days), comparing favorably to tunneled catheters. To conclude, temporary catheters are associated with a low rate of complications and an acceptable rate of interventions. Therefore, they could be the optimal vascular access in very elderly patients when the placement of an arterio-venous fistula is not feasible.

Comparison between kidney and continuous plasma perfusion for paraquat elimination

BACKGROUND

Thousands of paraquat (PQ)-poisoned patients continue to die. Plasma perfusion (PP) has recently been incorporated as a method of clinical detoxification. The purpose of this study was to estimate the PQ clearance of PP and observe the effect of PP on PQ concentration in the blood of patients with acute PQ poisoning.

METHODS

Twenty one PQ-poisoned patients admitted to our poisoning center within 24 hours after the ingestion were prospectively enrolled. Continuous plasma perfusion was performed. Urinary PQ and plasma PQ concentration level at inlet/outlet of the cartridge were obtained right before and 1.5 hours after the start of each perfusion session for the calculation of renal and plasma PQ excretion.

RESULTS

In all 8 rounds (108 sessions) of PP on the 21 patients, PQ clearance rate (mL/min) by PP was always found to be higher than the renal value: (1st 11.14 ± 6.13 versus 6.53 ± 1.46; 2nd 18.36 ± 11.32 versus 6.23 ± 1.51; 3rd 16.13 ± 10.05 versus 4.01 ± 0.93; 4th 12.86 [6.72, 17.47] versus 2.42 [0.65, 4.20]; 5th 14.12 [10.48, 35.20] versus 1.77 [0.63, 2.91]; 6th 16.47 [11.82; 20.69] versus 1.70 [0.23, 3.18]; 7th 13.33 [9.71, 18.75] versus 1.10 [0.14, 2.99]; 8th 11.27 [9.21, 16.02] versus 1.10 [0.09, 2.79], P < 0.05). The survivors showed a higher plasma PQ reduction rate (mg L hour) than the nonsurvivors (0.57 ± 0.03 versus 0.47 ± 0.06, P < 0.05).

CONCLUSIONS

Our data show that PP therapies help in the clearance of PQ and may prove a promising therapeutic tool in patients with acute PQ intoxication.

Two single-lumen noncuffed catheters in the jugular vein as long-term vascular access: a preliminary report

Two single-lumen, noncuffed catheters in the same jugular vein have been used as preferred vascular access in our hemodialysis (HD) and apheresis patients in past years. The aim of this retrospective study was to analyze the clinical outcome of such a vascular access and the reasons for catheter removal. In 129 adult patients, aged 69 ± 13 years, 56% males, treated by HD (121 patients) or apheresis (8 patients), two single lumen, pre-curved 8 Fr catheters (Medcomp, Harleysville, PA, USA) inserted into the same jugular vein were used as vascular access between January 2009 and April 2010. The catheters were inserted into the left jugular vein in 21 patients, and into the right jugular vein in 108 patients. A 30% solution of trisodium-citrate was used as a locking solution, and 2% mupirocin ointment was routinely applied to the exit site. The catheters were removed in 86 patients after 1-288 days, median 17.5 days. In 74 patients, there was either no need for further dialysis or an arteriovenous fistula was constructed (17 patients). In 10 patients, wire exchange was performed for correction of a displaced functional catheter (after 6-201 days), and in only two patients the catheters were removed due to infection on days 10 and 184. The longest period of a catheter functioning without intervention was 387 days. Fifteen patients died with functional catheters left in place (duration 1-387 days). In four patients, the catheters were still functional at the time of analysis (duration 198-268 days). Another nine patients were transferred to other dialysis centers (after they had been followed up at our center lasting for 1-63 days), with no data on their outcome after transfer. Fifteen patients were lost to follow up after insertion. Two single-lumen, noncuffed catheters in the same jugular vein, locked with 30% citrate, seem to be a safe and long lasting method of vascular access for hemodialysis and apheresis in some patients, but further prospective studies are needed to evaluate the clinical outcome of this type of vascular access.