Table 2.
Comparison of signs and symptoms at presentation between COVID-19 patients with hyponatraemia, normonatremia and hypernatraemia
| Signs and symptoms | Hyponatraemia Na≤134 mmol/L N=2677 |
Normonatremia Na 136–145 mmol/L N=5008 |
Hypernatraemia Na≥146 mmol/L N=126 |
| Nausea/vomiting (N (%)) | 679/2273 (29.9%) P=0.04 |
1150/4129 (27.9%) | 16/83 (19.3%) P=0.04 |
| Diarrhoea (N (%)) | 804/2298 (35.0%) P<0.001 |
1146/4157 (27.6%) | 15/82 (18.3%) |
| Anosmia (N (%)) | 244/1904 (12.8%) P=0.002 |
352/3330 (10.6%) | 1/66 (1.5%) |
| Confusion (N (%)) | 311/2319 (13.4%) | 651/4381 (14.9%) | 45/105 (42.9%) P<0.001 |
| Seizures (N (%)) | 10/1977 (0.5%) P=0.20 |
31/3452 (0.9%) | 0/80 (0.0%) P=0.20 |
| FiO2 (median fraction (IQR)) | N=1159 0.36 (0.28–0.50) P=0.05 |
N=2084 0.36 (0.28–0.50) |
N=67 0.44 (0.30–0.80) P=0.05 |
| SBP (mean SBP in mm Hg (SD)) | N=2648 132 (± 22) P<0.001 |
N=4971 135 (±23) |
N=120 135 (± 25) P=1.00 |
| HR (mean HR in BPM (SD)) | N=2661 92 (±18) P=0.003 |
N=4965 91 (±20) |
N=123 95 (±25) P=0.034 |
| Capillary refill≥3 s (N (%)) | 81/863 (9.4%) | 93/1369 (6.8%) | 6/33 (18.2%) P=0.008 |
| Blood urea level (median level n mmol/L (IQR)) | N=2549 6.3 (4.5–9.3) P=0.87 |
N=4776 6.2 (4.5–9.2) |
N=115 12.6 (7.9–25.3) P<0.001 |
| eGFR rate using 2021 CKD-epi creatinine equation in (median clearance in mL/min/1.73 m3 (IQR)) | N=2656 64 (45–90) P<0.001 |
N=4983 68 (46–94) |
N=125 41 (24–71) P<0.001 |
| CT severity score (mean score (SD)) | N=909 12.4 (±5.5) P=0.58 |
N=1401 12.1 (±5.6) |
N=30 14.5 (±7.2) P=0.06 |
| Blood CRP level (median level in mg/L (IQR)) | N=2646 93.1 (49.0–154) P<0.001 |
N=4939 70.8 (28.0–131) |
N=123 75.0 (29.0–148) P=1.00 |
| Blood LDH level (median level in U/L (IQR)) | N=2238 349 (268–471) P<0.001 |
N=4226 323 (247–426) |
N=89 363 (255–447) P=0.52 |
| MEWS (median score (IQR)) | N=2337 3.0 (2.0–4.0) P<0.001 |
N=4055 3.0 (2.0–4.0) |
N=103 4.0 (2.0–5.0) P<0.001 |
| qSOFA (median score (IQR)) | N=2373 1.0 (0.0–1.0) P=1.00 |
N=4131 1.0 (0.0–1.0) |
N=104 1.0 (1.0–1.0) P<0.001 |
Significance was assessed using a Kruskal-Wallis test with post hoc correction (for numerical data; non-normally distributed), one-way ANOVA (for numerical data; normally distributed) or χ2 test (for categorical data). P values for all groups indicate significance when compared with the normonatremia group. When no p value was provided, there was no significant difference to the normonatremia group. Subgroup analyses for hyponatraemia are provided in the online supplemental information.
%, percentage of patients in this group with indicated characteristic; BPM, beats per minute; CKD-epi, Chronic Kidney Disease Epidemiology Collaboration; CRP, C reactive protein; eGFR, estimated glomerular filtration rate; HR, heart rate; LDH, lactate dehydrogenase; MEWS, Modified Early Warning Score; qSOFA, Quick Sequential Organ Failure Assessment; SBP, systolic blood pressure.