Abstract: Objective To observe the efficacy and safety of fistula cannulation using a 15G needle in maintenance hemodialysis (MHD) patients.  Methods  This was a prospective and self-control study. A total of 26 MHD patients with mature arteriovenous fistula and routine blood flow rate of ≥350ml/min were enrolled in this study. All patients underwent high-flux hemodialysis for 6 continuous sessions, and blood flow rate was set at 350ml/min using a 16G or a 15G puncture needle. During each session, we monitored the effective blood flow rate (EBFR), arterial pressure (AP), venous pressure (VP), transmembrane pressure (TMP), online urea clearance using an online clearance monitor (OCM), and calculated single-chamber urea solute clearance index (spKt/V) by blood sampling. We recorded the impact of 16G and 15G needles on the time of compression (TC) after needle removal, pain score of the patients, and the related adverse events in the follow-up period.  Results  When the pump speed was set at 350ml/min using a 15G puncture needle, EBFR [(322.63±15.41)ml/min vs. (315.36±11.42)ml/min, t=-2.776，P=0.013] and OCM-spKt/V [(1.18±0.13) vs. (1.14±0.14), t=-2.178, P=0.045] were higher than those using a 16G puncture needle; AP [(-129.61±25.71)mmHg vs. (-191.27±20.05)mmHg, t=-8.441, P＜0.001] and VP [(139±11.77)mmHg vs. (167.81±10.23)mmHg, t=8.822, P＜0.001]were significantly lower than those using a 16G puncture needle. The time of compression after the needle removal using a 15G needle was longer than that using a 16G needle [(60.19±23.25) min vs. (54.99±20.51)min, t=3.188, P=0.004]. There was no significant difference in score of pain [(1.56±1.29) vs. (1.93±1.6), t=1.336, P=0.200].  Conclusions  When the blood flow rate was set at ≥350ml/min, the use of a 15G needle can significantly increase the real blood flow compared with that of a 16G needle, thereby improving the dialysis adequacy. There is no significant difference in score of pain, but the time of compression after needle removal was longer in patients using a 15G needle than in those using a 16G needle.

Key words:  Hemodialysis, Arteriovenous fistula, Needle, Dialysis adequacy