Table 2.
Characteristics at consecutive isolated hemodialysis sessions following COVID-19 diagnosis
| Cohort | Characteristic | HD1 | HD2 | HD3 | P value HD1-HD2-HD3 |
|---|---|---|---|---|---|
| Total | Number of patients, n | 85 | 77 | 70 | |
| Pre-HD SaO2 (%) | 98 (97–100) | 98 (95–100) | 98 (95–100) | 0.2 | |
| Post HD SaO2 (%) | 98 (96–100) | 98 (96–100) | 98 (95–100) | 0.9 | |
| Any documented hypoxia (SaO2 <93%) | 14 (16) | 13 (17) | 13 (19) | 0.9 | |
| Pre-HD SBP (mm Hg) | 149 (133–164) | 147 (130–165) | 133 (129–164) | 0.8 | |
| Post HD SBP (mm Hg) | 144 (129–162) | 142 (130–165) | 147 (125–164) | 0.99 | |
| Lowest recorded SBP (mm Hg) | 131 (110–148) | 128 (113–147) | 133 (112–145) | 0.9 | |
| Pre-HD weight (kg) | 74 (66–1150) | 75 (67–113) | 74 (66–111) | 0.97 | |
| Net UF (l) | 1.5 (1.0–2.0) | 1.5 (1.0–2.0) | 1.4 (1.0–2.0) | 0.6 | |
| Net UF / pre-HD weight (%) | 2.2 (1.2–2.7) | 2.1 (1.2–2.8) | 1.9 (1.2–4.7) | 0.6 | |
| Outpatient only | Number of patients, n | 56 (66) | 55 (71) | 55 (79) | |
| Pre-HD SaO2 (%) | 99 (97–100) | 98 (96–100) | 98 (97–100) | 0.5 | |
| Post HD SaO2 (%) | 98 (97–100) | 99 (97–100) | 99 (97–100) | 0.8 | |
| Any documented hypoxia (SaO2 <93%) | 4 (7) | 3 (5) | 6 (11) | 0.6 | |
| Pre-HD SBP (mm Hg) | 147 (130–164) | 145 (123–170) | 152 (133–164) | 0.9 | |
| Post HD SBP (mm Hg) | 144 (128–161) | 142 (127–164) | 149 (132–165) | 0.6 | |
| Lowest recorded SBP (mm Hg) | 132 (115–149) | 127 (112–146) | 136 (116–153) | 0.5 | |
| Pre-HD weight (kg) | 75 (66–85) | 75 (66–86) | 74 (66–85) | 0.98 | |
| Net UF (l) | 1.5 (1.0–2.0) | 1.5 (1.0–2.0) | 1.5 (1.0–2.0) | 0.9 | |
| Net UF / pre-HD weight (%) | 2.3 (1.3–2.7) | 2.2 (1.2–2.8) | 2.1 (1.4–2.7) | 0.8 | |
| Future hospital admission | Number of patients, n | 29 (34) | 22 (29) | 15 (21) | |
| Pre-HD SaO2 (%) | 98 (94–99) | 96 (93–98)a | 95 (89–96)b | 0.004 | |
| Post HD SaO2 (%) | 96 (94–99)c | 94 (89–96)d | 94 (91–96)e | 0.06 | |
| Any documented hypoxia (SaO2 <93%) | 10 (34)f | 10 (45)g | 7 (47)h | 0.6 | |
| Pre-HD SBP (mm Hg) | 152 (136–169) | 149 (140–164) | 126 (108–150) | 0.09 | |
| Post HD SBP (mm Hg) | 150 (134–175) | 142 (132–171) | 131 (117–163) | 0.3 | |
| Lowest recorded SBP (mm Hg) | 126 (106–146) | 130 (115–148) | 116 (103–134) | 0.4 | |
| Pre-HD weight (kg) | 73 (67–87) | 72 (68–86) | 73 (66–85) | 0.98 | |
| Net UF (l) | 1.5 (1.0–1.9) | 1.4 (1.0–1.9) | 1.0 (0.5–1.5)i | 0.3 | |
| Net UF / pre-HD weight (%) | 1.7 (1.2–2.5) | 1.9 (1.3–2.5) | 1.3 (0.8–2.1) | 0.4 | |
| Survived 28 days | Number of patients, n | 69 (81) | 65 (84) | 63 (90) | |
| Pre-HD SaO2 (%) | 99 (97–100) | 98 (96–100) | 98 (96–100) | 0.3 | |
| Post HD SaO2 (%) | 98 (97–100) | 99 (97–100) | 99 (97–100) | 0.9 | |
| Any documented hypoxia (SaO2 <93%) | 9 (13) | 7 (11) | 9 (15) | 0.8 | |
| Pre-HD SBP (mm Hg) | 149 (131–163) | 145 (126–167) | 147 (129–164) | >0.99 | |
| Post HD SBP (mm Hg) | 144 (127–161) | 142 (128–163) | 149 (128–163) | 0.7 | |
| Lowest recorded SBP (mm Hg) | 132 (111–149) | 128 (112–147) | 135 (113–148) | 0.7 | |
| Pre-HD weight (kg) | 74 (65–84) | 75 (67–85) | 74 (66–85) | 0.9 | |
| Net UF (l) | 2.0 (1.5–3.3) | 1.5 (1.0–2.0) | 1.5 (1.0–2.0) | 0.5 | |
| Net UF / pre-HD weight (%) | 2.3 (1.4–2.7) | 2.1 (1.3–2.8) | 1.9 (1.3–2.6) | 0.5 | |
| Death by 28 days | Number of patients, n | 16 (19) | 12 (16) | 7 (10) | |
| Pre-HD SaO2 (%) | 98 (93–99) | 96 (87–98) | 94 (86–95)j | 0.05 | |
| Post HD SaO2 (%) | 96 (93–100) | 94 (86–96)k | 93 (91–95)l | 0.02 | |
| Any documented hypoxia (SaO2 <93%) | 5 (31) | 6 (50)m | 4 (57) | 0.4 | |
| Pre-HD SBP (mm Hg) | 153 (138–175) | 151 (144–166) | 140 (108–185) | 0.5 | |
| Post HD SBP (mm Hg) | 159 (135–181) | 143 (132–184) | 131 (117–174) | 0.3 | |
| Lowest recorded SBP (mm Hg) | 127 (100–145) | 128 (119–148) | 116 (103–134) | 0.6 | |
| Pre-HD weight (kg) | 69 (66–88) | 69 (67–88) | 70 (60–89) | 0.9 | |
| Net UF (l) | 1.2 (0.8–1.5) | 1.1 (0.9–1.8) | 1.0 (0.5–1.5) | 0.6 | |
| Net UF / pre-HD weight (%) | 1.6 (1.1–2.0) | 1.5 (1.2–2.3) | 1.2 (0.8–2.8) | 0.6 |
COVID-19, coronavirus disease 2019; HD, hemodialysis; SaO2, oxygen saturations measured by peripheral pulse oximetry; SBP, systolic blood pressure; UF, ultrafiltration.
The Outpatient-only cohort did not require admission to hospital during the course of COVID-19 disease and recovery. The Admitted cohort received inpatient care and hemodialysis at any point during COVID-19 disease. Data are reported as n (%) for categorical variables and median (interquartile range) for continuous variables. Due to progressive clinical deterioration and requirement for hospitalization, the cohort sizes decreased at consecutive dialysis sessions, particularly in the future hospital admission and death by 28 days cohorts.
P value HD1-HD2-HD3 represents differences among the 3 HD sessions calculated with χ2 for categorical and repeated measures analysis of variance test for continuous variables. Differences between clinical outcome cohorts were calculated with Fisher’s exact test for categorical and Mann-Whitney test for continuous variables. P values were adjusted for multiple analysis with Bonferroni-Dunn method.
P < 0.001 compared with Outpatient-only cohort. Difference between medians 2% (95% confidence interval [CI] 1%–4%).
P < 0.001 compared with Outpatient-only cohort. Difference between medians 3% (95% CI: 3%–5%).
P = 0.007 compared with Outpatient-only cohort. Difference between medians 2% (95% CI: 1%–3%).
P < 0.001 compared with Outpatient-only cohort. Difference between medians 5% (95% CI: 3%–6%).
P < 0.001 compared with Outpatient-only cohort. Difference between medians 5% (95% CI: 3%–6%).
P = 0.01 compared with Outpatient-only cohort. Odds ratio (OR) for future hospital admission for hypoxia at HD1 = 6.8 (95% CI: 1.8–21.1).
P < 0.001 compared with Outpatient-only cohort. OR for future hospital admission for hypoxia at HD2 = 14.4 (95% CI: 3.7–52.2).
P = 0.01 compared with Outpatient-only cohort. OR for future hospital admission for hypoxia at HD3 = 7.1 (95% CI: 1.8–23.7).
P = 0.04 compared with Outpatient-only cohort. Difference between medians 0.5 l (95% CI: 0.001–0.8 l).
P < 0.001 compared with Survived cohort. Difference between medians 4% (95% CI: 3%–11%).
P < 0.001 compared with Survived cohort. Difference between medians 5% (95% CI: 3%–7%).
P < .001 compared with Survived cohort. Difference between medians 6% (95% CI: 3%–7%).
P = 0.01 compared with Survived cohort. OR for death within 28 days for hypoxia at HD2 = 8.3 (95% CI: 2.3–30.3).