Table 1. Patient characteristics.
| Characteristic | Overall | High bicarbonate | Normal bicarbonate | Low bicarbonate |
|---|---|---|---|---|
| n = 60 | n = 13 | n = 30 | n = 17 | |
| Age, years | 72 (64, 78) | 74 (71, 83) | 72 (65, 78) | 70 (61, 78) |
| Male, n (%) | 36 (60%) | 5 (38%) | 19 (63%) | 12 (71%) |
| BMI | 25.0 (22.3, 28.7) | 25.1 (22.4, 25.7) | 25.3 (23.4, 28.9) | 22.3 (20.9, 29.5) |
| Treatment limitation | 16 (27%) | 3 (23%) | 7 (23%) | 6 (35%) |
| Hypertension, n (%) | 34 (57%) | 6 (46%) | 17 (57%) | 11 (65%) |
| Diabetes, n (%) | 17 (28%) | 4 (31%) | 8 (27%) | 5 (29%) |
| Heart disease, n (%) | 9 (15%) | 1 (7.7%) | 3 (10%) | 5 (29%) |
| Dementia, n (%) | 4 (6.7%) | 2 (15%) | 0 (0%) | 2 (12%) |
| Chronic lung disease, n (%) | 4 (6.7%) | 0 (0%) | 3 (10%) | 1 (5.9%) |
| Body temperature, °C | 38.1 (37.4, 38.5) | 38.1 (37.9, 38.6) | 37.7 (37.0, 38.4) | 38.3 (38.2, 38.5) |
| Respiratory rate, bpm/min | 24 (22, 31) | 22 (20, 24) | 24 (22, 28) | 30 (25, 34) |
| SpO2, % | 92 (88, 94) | 91 (88, 93) | 92 (89, 94) | 93 (91, 94) |
| FiO2 | 0.32 (0.28, 0.50) | 0.28 (0.28, 0.32) | 0.30 (0.28, 0.50) | 0.36 (0.28, 0.60) |
| SOFA score | 3 (2, 4) | 3 (2, 3) | 2 (2, 3) | 4 (2, 6) |
| Respiratory sub-SOFA score | 2 (2, 2) | 2 (2, 2) | 2 (2, 2) | 2 (2, 2) |
| Renal sub-SOFA score | 0 (0, 0) | 0 (0, 0) | 0 (0, 0) | 0 (0, 1) |
| C-reactive protein, mg/L | 7.0 (4.4, 12.5) | 7.9 (2.7, 13.2) | 7.5 (3.4, 14.0) | 6.6 (4.8, 8.0) |
| Ferritin, ng/mL | 570 (310, 934) | 369 (185, 410) | 699 (365, 969) | 535 (261, 958) |
| Creatinine, mg/dL | 0.8 (0.7, 1.1) | 0.7 (0.6, 1.0) | 0.8 (0.7, 0.9) | 1.1 (1.0, 1.6) |
| Bicarbonate, mEq/L | 22.5 (21.6, 24.5) | 24.7 (23.0, 27.4) | 23.1 (22.1, 24.3) | 20.4 (17.8, 22.0) |
| Potassium, mEq/L | 3.8 (3.3, 3.9) | 3.5 (3.3, 3.8) | 3.8 (3.4, 3.9) | 3.8 (3.4, 3.9) |
| Medications | ||||
| ACE inhibitors, n (%) | 3 (5.0%) | 1 (7.7%) | 1 (3.3%) | 1 (5.9%) |
| ARB, n (%) | 16 (27%) | 3 (23%) | 6 (20%) | 7 (41%) |
| Aldosterone blockers, n (%) | 2 (3.3%) | 1 (7.7%) | 0 (0%) | 1 (5.9%) |
| Renin blockers, n (%) | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) |
| Loop diuretics, n (%) | 7 (12%) | 2 (15%) | 2 (6.7%) | 3 (18%) |
Statistics presented: Median (IQR) or n (%)
BMI; Body Mass Index, SpO2; peripheral oxygen saturation, FiO2; fraction of inspiratory oxygen, SOFA; peripheral oxygen saturation, ACE; angiotensin-converting enzyme, ARB; angiotensin receptor antagonist.