Table 1.
Baseline characteristics of patients included in the observational study.
| Characteristic | Vitamin C group (n = 10) | Control group (n = 103) | p-value |
|---|---|---|---|
| Age, years | 70.5 (58.0–75.0) | 69.0 (55.0–77.0) | 0.927 |
| Female sex | 3 (30.0) | 25 (24.3) | 0.709 |
| Race | 1.000 | ||
| Caucasian | 10 (100.0) | 100 (97.1) | |
| Asian/Middle Eastern | 0 (0.0) | 2 (1.9) | |
| African | 0 (0.0) | 1 (1.0) | |
| Comorbidity | 7 (70.0) | 77 (74.8) | 0.715 |
| Chronic kidney disease | 2 (20.0) | 13 (12.6) | 0.620 |
| Chronic lung disease | 1 (10.0) | 16 (15.5) | 1.000 |
| Heart condition | 3 (30.0) | 25 (24.3) | 0.707 |
| Hypertension | 6 (60.0) | 55 (53.4) | 0.751 |
| Liver disease | 0 (0.0) | 0 (0.0) | - |
| Diabetes mellitus | 3 (30.0) | 23 (22.3) | 0.694 |
| Malignancy | 0 (0.0) | 9 (8.7) | 1.000 |
| SOFA score on the day of intubation | 4.0 (4.0–5.3) | 4.0 (4.0–5.0) | 0.743 |
| Respiratory | 4.0 (4.0–4.0) | 4.0 (4.0–4.0) | 0.139 |
| Coagulation | 0.0 (0.0–0.3) | 0.0 (0.0–0.0) | 0.708 |
| Hepatic | 0.0 (0.0–0.0) | 0.0 (0.0–0.0) | 0.363 |
| Cardiovascular | 0.0 (0.0–0.0) | 0.0 (0.0–0.0) | 0.363 |
| Neurologic | 0.0 (0.0–0.0) | 0.0 (0.0–0.0) | 0.397 |
| Renal | 0.0 (0.0–1.0) | 0.0 (0.0–0.0) | 0.587 |
| Days from symptom onset to intubation | 5.5 (3.8–9.3) | 7.0 (4.0–11.0) | 0.314 |
| Usage of high-flow nasal oxygen | 8 (80.0) | 69 (67.0) | 0.499 |
| Duration of high-flow nasal oxygen, days | 1.5 (1.0–5.8) | 2.0 (1.0–4.5) | 0.930 |
| Usage of non-rebreather mask | 0.0 (0.0) | 22 (21.4) | 0.205 |
| Duration of non-rebreather mask, days | NA | 2.0 (1.0–3.0) | NA |
| Lung mechanics on the day of intubation | |||
| Ventilation mode | 0.013 | ||
| Volume Control | 10 (100.0) | 61 (59.2) | |
| Pressure Control | 0.0 (0.0) | 42 (40.8) | |
| Respiratory rate, bpm | 25.0 (22.0–30.0) | 25.0 (22.0–28.0) | 0.722 |
| Tidal volume, mL | 475.0 (442.5–500.0) | 480.0 (440.0–490.0) | 0.775 |
| PEEPext, cmH2O | 10.5 (10.0–14.0) | 12.0 (10.0–13.0) | 0.857 |
| PEEPtotal, cmH2O | 10.5 (10.0–14.0) | 13.0 (10.0–15.0) | 0.237 |
| Pplateau, cmH2O | 24.5 (22.3–27.8) | 25.0 (23.0–27.8) | 0.760 |
| Pdriving, cmH2O | 13.0 (13.0–14.8) | 12.0 (10.0–14.3) | 0.223 |
| FiO2 | 1.0 (0.9–1.0) | 0.9 (0.7–1.0) | 0.052 |
| PaO2, mmHg | 76.5 (68.3–145.8) | 110.0 (95.0–140.0) | 0.040 |
| PaO2:FiO2 | 95.4 (68.3–145.8) | 142.5 (113.3–182.5) | 0.012 |
| PaCO2, mmHg | 50.5 (42.9–58.5) | 47.0 (41.0–56.0) | 0.511 |
n, number; NA, not applicable; SOFA, sequential organ failure assessment; bpm, breaths per minute; PEEP, positive end expiratory pressure; Pplateau, plateau pressure; Pdriving, driving pressure; PaO2, partial pressure of arterial oxygen; FiO2, fraction of inspired oxygen; PaCO2, partial pressure of arterial carbon dioxide. Data are presented as median (interquartile range) or number (%).
Heart condition included congestive heart failure, coronary artery disease, and cardiomyopathies.