Hemodialysis catheter design and catheter performance: a randomized controlled trial.

BACKGROUND: A complication of long-term use of tunneled cuffed catheters for hemodialysis is the high rate of infection and thrombus-related dysfunction. Specific mechanical features of tunneled cuffed catheters may improve hemodynamic performance and decrease thrombosis and infection rates. However, there currently is no proven advantage of one design over another. STUDY DESIGN: Single-center randomized clinical trial. SETTING & PARTICIPANTS: 302 hemodialysis patients who required a tunneled cuffed catheter as temporary or definite vascular access. INTERVENTION: Palindrome Symmetric Tip Dialysis Catheter or HemoStar Long-Term Hemodialysis Catheter. OUTCOMES & MEASUREMENTS: The primary end point was primary assisted patency. Secondary end points were incidence of catheter-related bloodstream infections (CRBSIs), thrombosis, and 2 indicators of rheologic function: mean effective blood flow rate and urokinase use. RESULTS: Mean primary assisted patency was 135.9 days for Palindrome and 136.5 days for HemoStar (P=0.8). Definite CRBSI occurred in 0.24 and 0.10/1,000 catheter-days for Palindrome and HemoStar, respectively (P=0.3). Removal rates for thrombosis that could not be resolved with thrombolysis were 0.53 and 0.43/1,000 catheter-days for Palindrome and HemoStar, respectively (P=0.7). Urokinase use was lower for Palindrome than for HemoStar, as evidenced by a lower number of urokinase infusions/1,000 catheter-days (17 and 35; P<0.001) and higher number of catheters that never required thrombolysis (58% and 45%; P=0.03). Mean effective blood flow rate was higher for Palindrome than for HemoStar (333 and 304mL/min; P<0.001). LIMITATIONS: Single-center nonblinded trial. CONCLUSIONS: Primary assisted patency and incidence of infection and thrombosis were similar for both catheter types. The Palindrome catheter required less thrombolysis and achieved higher blood flow rates than the HemoStar catheter. These findings suggest that mechanical catheter design may improve catheter rheology, but does not affect risks for thrombosis and infection and hence catheter survival.

Influenza vaccination and humoral alloimmunity in solid organ transplant recipients.

Annual influenza vaccination is recommended in solid organ transplant (SOT) recipients. However, concerns have been raised about the impact of vaccination on antigraft alloimmunity. We evaluated the humoral alloimmune responses to influenza vaccination in a cohort of SOT recipients between October 2008 and December 2011. Anti-HLA antibodies were measured before and 4-8 weeks after influenza vaccination using a solid-phase assay. Overall, 169 SOT recipients were included (kidney = 136, lung = 26, liver = 3, and combined = 4). Five (2.9%) of 169 patients developed de novo anti-HLA antibodies after vaccination, including one patient who developed donor-specific antibodies (DSA) 8 months after vaccination. In patients with pre-existing anti-HLA antibodies, median MFI was not significantly different before and after vaccination (P = 0.73 for class I and P = 0.20 for class II anti-HLA antibodies) and no development of de novo DSA was observed. Five episodes of rejection (2.9%) were observed within 12 months after vaccination, and only one patient had de novo anti-HLA antibodies. The incidence of development of anti-HLA antibodies after influenza vaccination in our cohort of SOT recipients was very low. Our findings indicate that influenza vaccination is safe and does not trigger humoral alloimmune responses in SOT recipients.

Magnesium and infection risk after kidney transplantation: An observational cohort study.

OBJECTIVES: Magnesium is a co-factor in natural killer and T cell reactivity and may modify the course of infections. We examined the association between baseline serum magnesium concentration and infections requiring admission the first year after kidney transplantation. METHODS: Inclusion of adults transplant recipients between January 2003 and 31 December 2013. Cox piecewise linear regression model estimating the hazard ratio for first admission for infection. Outcomes until one year post-transplantation or up to May 1, 2014. RESULTS: Overall, 371 of 873 persons were admitted at least once the first year after transplantation (65 events per 100 person-years). The infection-specific cumulative incidence increased with lower serum magnesium concentration (P = 0.008). After adjustment for confounders, a low serum magnesium was associated with an increased hazard of infection (P < 0.0001 in type 3 test). With 2 mg/dL as the reference value, every 0.1 mg/dL reduction in serum magnesium at baseline below 2 mg/dL (N = 165) increased the hazard ratio by 15% (HR 1.15, 95%CI 1.05-1.27; P = 0.002) while every increase of 0.1 mg/dL in those with a serum magnesium between 2 and 3 mg/dL (N = 661) decreased the hazard ratio by 4% (HR 0.96, 95%CI 0.93-1.00; P = 0.08). CONCLUSION: A lower baseline serum magnesium concentration is associated with an increased risk of infection after kidney transplantation.

Pelvic floor spasms in children: an unknown condition responding well to pelvic floor therapy.

OBJECTIVE: During a study period of 4 years, 21 children are seen for night time pelvic pain. These children typical wake up in the middle of the night with severe lower abdominal or perineal pain. During day some of them suffer urge syndrome. During urodynamic investigation extremely high pelvic floor activity as recorded by high urethral pressure was observed in these children. We therefore started pelvic floor relaxation biofeedback in these children. METHODS: All children diagnosed with pelvic floor spasms underwent biofeedback pelvic floor relaxation therapy in order to learn them to counteract pelvic pain due to these spasms. In those girls in whom detrusor hyperactivity was seen on urodynamics concomitant anticholinergic treatment was given (oxybutynin). RESULTS: Between January 1998 and January 2002 symptomatic pelvic floor spasms were diagnosed in 21 children (19 girls/2 boys). Pelvic floor relaxation biofeedback was successful for treatment of this condition in 17 of 21 children. Mean duration of therapy was 3 months (12 weekly sessions) and on long term follow-up relapse was seen in 3 of 17 successfully treated children. 10 of 17 successfully treated children received anticholinergics. CONCLUSION: Pelvic floor spasms in children (which can be secondary to detrusor overactivity) respond well to pelvic floor relaxation therapy.