Static pressures, intra-access blood flow and dynamic Kt/V profiles in the prediction of dialysis access function

Table 1 Baseline patient characteristics

Variables	Full cohort (n = 107)	Normal Kt/V profile (n = 68)	Abnormal Kt/V profile (n = 39)	P-value
Demographics
Age (yr)	54.9 ± 1.5	56.5 ± 1.8	52.3 ± 2.8	0.210
Male gender (%)	52.3	46.1	53.8	0.843
Access types
AV fistula (%)	63.5	58.8	71.8	1.000
AV graft (%)	36.5	41.2	28.2	1.000
Access pressures and flow rates
Static PA (mmHg)	-196.7 ± 4.1 (-203)1	-196.2 ± 4.6 (-202)	-197.5 ± 7.9 (-206)	0.884
Static PV (mmHg)	240.8 ± 5.5 (244)	249.9 ± 7.2 (254)	224.8 ± 7.9 (235)	0.021
Intra-access flow rate	1369.5 ± 82.8 (1070)	1256.3 ± 87.4 (1035)	1566.8 ± 165.6 (1170)	0.103
Adequacy of dialysis
Measured Kt/V	1.42 ± 0.04 (1.46)	1.40 ± 0.04 (1.44)	1.45 ± 0.07 (1.51)	< 0.001
Access recirculation > 5% (n = 21) (%)	18.7	17.4	20.5	0.429

¹Median values in parenthesis.

Table 2 Relationships between static access pressures, access blood flow and Kt/V profiles

Strength of association
Variables	rs	P-value
Static PA – Kt/V profiles	-0.05	0.636
Static PA – Kt/V	-0.14	0.155
Static PV – Kt/V profiles	0.19	0.047
Static PVQTRL – Kt/V profiles	-0.17	0.078
Static PA – Intra-access blood flow	-0.25	0.009
Static PA – Intra-AVF blood flow	-0.22	0.069
Static PA – Intra-AVG blood flow	-0.16	0.319
Static PV – Intra-access blood flow	0.04	0.666
Intra-access blood flow - Kt/V profile	-0.12	0.208
Intra-AVF blood flow - Kt/V profile	0.17	0.174
Intra-AVG blood flow - Kt/V profile	0.05	0.783
Critical intra-access blood flow - PA	0.24	0.226
Critical intra-access blood flow - PV	0.14	0.482
Critical intra-access blood flow – Kt/V profile	0.01	0.962
20% reduced intra-access blood flow – Static PA	-0.15	0.262
20% reduced intra-access blood flow – Static PV	-0.03	0.851
20% reduced intra-access blood flow – Kt/V profile	0.14	0.294
Access recirculation > 5% - Kt/V profile	0.20	0.389
Kt/V – Kt/V profile	-0.08	0.397