Table 1.
Characteristics of patients who are deemed optimal, appropriate, and not ideal for a 2-times weekly hemodialysis (HD) schedule
| Characteristic | Optimal for 2-times weekly HD (n = 112) |
Appropriate for 2-times weekly HD (n = 107) |
Nonideal for 2-times weekly HD (n = 191) |
|---|---|---|---|
| Demographic | |||
| Age, yr | 58.9 ± 15.0 | 58.0 ± 14.2 | 55.9 ± 16.1 |
| Female gender, % (n)a | 53.6 (60) | 37.4 (40) | 41.7 (71) |
| Race/ethnicity % (n)a | |||
| White/non-Hispanic | 29.5 (33) | 26.2 (28) | 24.6 (47) |
| White/Hispanic | 17.9 (20) | 15.9 (17) | 16.8 (32) |
| Black | 22.3 (25) | 26.2 (28) | 29.8 (122) |
| Asian | 17.9 (20) | 17.8 (19) | 7.3 (14) |
| Other or unknown | 12.5 (14) | 14.0 (15) | 15.2 (29) |
| Cause of ESRD, % (n)a | |||
| Diabetes mellitus | 51.8 (58) | 58.9 (63) | 45.5 (87) |
| Hypertension | 23.2 (26) | 13.1 (14) | 22.5 (43) |
| Glomerular disease | 10.7 (12) | 12.1 (13) | 16.2 (31) |
| Cystic/interstitial disease | 8.0 (9) | 3.7 (4) | 7.3 (14) |
| Other/unknown | 6.3 (7) | 12.1 (13) | 8.4 (16) |
| 24-Hour urine collection | |||
| Time interval between first HD and urine collection, daysa | 14 (7–235) | 29 (15–57) | 26 (12–48) |
| Collected during short (2-day) interdialytic period, % (n) | 36.6 (41) | 38.3 (41) | 42.4 (81) |
| Volume, mla | 1213 (800–1812) | 950 (700–1400) | 550 (400–963) |
| Urine volume > 500, ml, % (n)a | 91.1 (102) | 86.0 (92) | 55.0 (105) |
| Est. weekly urine volume, La,b | 6.9 (4.9–10.4) | 5.1 (4.1–7.8) | 3.4 (2.2–5.6) |
| Urea clearance, ml/mina,b | 4.0 (2.6–5.2) | 3.1 (2.0–4.3) | 1.5 (0.9–2.2) |
| Urea clearance > 3 ml/min, % (n)a | 67.9 (76) | 52.3 (56) | 11.5 (22) |
| stdKt/V (renal)a,b | 1.02 (0.75–1.28) | 0.75 (0.54–0.99) | 0.31 (0.21–0.46) |
| Medications prescribed | |||
| Diuretics, % (n) | 41.1 (46) | 36.4 (39) | 36.1 (69) |
| ACEI or ARB, % (n) | 58.9 (66) | 66.4 (71) | 68.6 (131) |
| EPO units/kg/g Hgb | 51 (29–79) | 63 (38–97) | 53 (33–83) |
| Laboratory data | |||
| Serum albumin, g/dl | 3.6 ± 0.4 | 3.5 ± 0.5 | 3.6 ± 0.4 |
| Hgb, g/dl | 11.2 ± 0.8 | 11.2 ± 0.9 | 10.9 ± 0.8 |
| Serum potassium, mEq/la | 4.6 ± 0.4 | 4.9 ± 0.5 | 4.7 ± 0.5 |
| Serum bicarbonate, mmol/l | 21.1 ± 2.2 | 21.2 ± 2.6 | 21.2 ± 2.3 |
| Serum phosphorus, mg/dla | 5.2 ± 0.9 | 5.5 ± 1.2 | 5.9 ± 1.4 |
| Pre-HD BUN, mg/dla | 54 ± 20 | 52 ± 18 | 61 ± 22 |
| Post-HD BUN, mg/dla | 18 ± 10 | 18 ± 8 | 23 ± 10 |
| Actual 3-times weekly HD prescription and adequacy parameters | |||
| Dialysis duration per HD, min | 180 ± 15 | 186 ± 14 | 187 ± 17 |
| spKt/Va | 1.30 ± 0.44 | 1.28 ± 0.29 | 1.14 ± 0.29 |
| Total Kt/V (incorporates KUR)a | 1.76 ± 0.36 | 1.66 ± 0.28 | 1.28 ± 0.30 |
| stdKt/V (dialysis)a | 2.08 ± 0.33 | 2.12 ± 0.29 | 1.90 ± 0.33 |
| stdKt/V (total)a | 3.19 (2.91–3.56) | 2.92 (2.75–3.26) | 2.35 (2.12–2.49) |
| UF volume per HD, La | 1.5 ± 0.7 | 2.6 ± 1.0 | 2.2 ± 1.4 |
| Total volume gains per week (est. weekly urine + weekly UF volume), La | 12.1 ± 4.3 | 13.8 ± 4.7 | 10.8 ± 4.4 |
| Dry weight, kga | 75.7 ± 19.1 | 74.0 ± 23.0 | 80.5 ± 21.7 |
| BSA, m2a | 1.83 ± 0.25 | 1.82 ± 0.29 | 1.90 ± 0.27 |
| Pre-HD systolic BP, mm Hga | 145 ± 16 | 151 ± 19 | 149 ± 19 |
| Pre-HD diastolic BP, mm Hg | 76 ± 9 | 78 ± 10 | 79 ± 13 |
| Post-HD systolic BP, mm Hga | 148 ± 20 | 142 ± 17 | 148 ± 19 |
| Post-HD diastolic BP, mm Hg | 78 ± 10 | 76 ± 8 | 79 ± 12 |
| HD access with catheter, % (n) | 69.6 (78) | 66.4 (71) | 64.9 (124) |
| Kinetic modeling data | |||
| Kd (modeled dialyzer clearance), ml/min | 267 ± 40 | 274 ± 39 | 266 ± 39 |
| G (urea generation rate), mg/min | 5.3 (4.0–7.0) | 5.5 (4.4–7.3) | 5.5 (4.2–7.4) |
| Urea distribution volume, La | 38.7 ± 9.6 | 41.1 ± 10.1 | 48.8 ± 13.2 |
| Theoretical 2-times weekly urine output, HD prescription requirement, and adequacy parametersc | |||
|---|---|---|---|
| Est. weekly urine volume (L)a,b | 8.1 (5.7–12.1) | 6.0 (4.8–9.2) | 4.0 (2.5–6.6) |
| stdKt/V (dialysis) needed to achieve 2.3 weekly goala | 1.12 (0.76–1.40) | 1.43 (1.19–1.68) | 1.93 (1.79–2.05) |
| spKt/V per HD, 2 times/wk, to achieve 2.3 stdKt/V goala | 0.87 (0.52–1.25) | 1.20 (0.92–1.66) | 2.47 (1.97–3.06) |
| Hours per HD needed to achieve spKt/Va | 2.0 (1.2–2.9) | 2.9 (1.9–3.6) | 6.4 (4.8–8.1) |
| % Able to reach adequacy goal with 2-times weekly HD ≤ 4-h treatment timea | 100 | 100 | 0 |
| UF volume per HD, La | 2.4 (1.6–3.3) | 3.9 (2.0–4.9) | 3.4 (2.3–4.4) |
| UF rate, ml/kg/ha | 7.9 (5.8–10.2) | 13.9 (10.1–17.9) | 11.0 (7.0–13.9) |
| UF rate, ml/kg/h per m2a | 4.4 (3.1–5.6) | 7.6 (5.3–10.9) | 5.6 (3.6–7.7) |
| UF rate ≤ 13 ml/kg/h, % (n)a | 100 (112) | 44.9 (48) | 72.8 (139) |
ACEI, angiotensin-converting enzyme inhibitor; ARB, angiotensin receptor blocker; BP, blood pressure; BSA, body surface area; BUN, blood urea nitrogen; EPO, erythropoietin; ESRD, end-stage renal disease; est., estimated; Hgb, hemoglobin; Kd, modeled dialyzer clearance spKt/V, single pool per treatment clearance; stdKt/V, standard weekly clearance of urea; UF, ultrafiltration.
Continuous values expressed as mean ± SD or median (25th−75th percentiles).
Statistically significant among groups by analysis of variance or χ2, P < 0.05, 2-sided.
Weekly urine volume estimation or urea clearance adjusted based on day of actual collection relative to interdialytic period, and adjusted for frequency of HD, either 3-times or 2-times weekly.
Where values were possible; 5 patients had mathematically impossible spKt/V requirements in the “nonideal” group who were not included in the analysis.