Table 1.
Demographics, comorbidities, clinical and laboratory data on hospital admission of the study population, according to the three study groups
| Study population | Oxygen Group n = 273 | CPAP Group n = 788 | BiPAP Group n = 232 | p+ | p# | p§ | |
|---|---|---|---|---|---|---|---|
| n. (%) | 1293 (100) | 273 (100) | 788 (100) | 232 (100) | |||
| Demographics, n.(%) | |||||||
| Age, median (IQR) years | 81 (73–86) | 80 (73–85) | 81 (73–86) | 80 (74–86) | 0.366 | 0.828 | 0.369 |
| Female sex | 635 (49) | 137 (50) | 389 (49) | 107 (46) | 0.548 | 0.385 | 0.648 |
| Comorbidities, n(%) | |||||||
| COPD | 406 (31) | 92 (34) | 241 (31) | 72 (32) | 0.633 | 0.798 | 0.357 |
| Diabetes | 495 (38) | 112 (41) | 292 (37) | 91 (39) | 0.482 | 0.549 | 0.294 |
| Chronic kidney disease | 353 (27) | 87 (32) | 215 (27) | 51 (22) | 0.046 | 0.106 | 0.057 |
| Hypertension | 974 (75) | 198 (72) | 594 (75) | 182 (78) | 0.306 | 0.336 | 0.227 |
| Atrial fibrillation | 264 (20) | 64 (23) | 154 (20) | 46 (20) | 0.376 | 0.924 | 0.163 |
| Congestive heart failure | 315 (24) | 67 (24) | 178 (23) | 70 (30) | 0.061 | 0.018 | 0.938 |
| Coronary artery disease | 599 (46) | 134 (49) | 360 (46) | 105 (45) | 0.585 | 0.909 | 0.304 |
| Valvulopaty | 300 (23) | 69 (25) | 193 (24) | 38 (16) | 0.024 | 0.009 | 0.361 |
| ACPE in the previous 12 months | 295 (23) | 63 (23) | 178 (23) | 54 (23) | 0.970 | 0.826 | 0.908 |
| Data on admission, n.(%) | |||||||
| Systolic blood pressure, median (IQR) mmHg | 160 (140–190) | 159 (135–180) | 164 (140–190) | 162 (140–185) | 0.043 | 0.900 | 0.012 |
| Diastolic blood pressure, median (IQR) mmHg | 90 (80–105) | 90 (75–100) | 95 (80–107) | 87 (75–100) | 0.000 | 0.001 | 0.025 |
| Mean blood pressure, median (IQR) mmHg | 115 (98–131) | 113 (95–127) | 117 (99–133) | 113 (98–127) | 0.084 | 0.217 | 0.064 |
| Hypotension* | 19 (1) | 4 (1) | 14 (2) | 1 (< 1) | 0.321 | 0.132 | 0.992 |
| Heart rate, median (IQR) beats/min | 104 (90–120) | 100 (86–113) | 108 (95–120) | 102 (92–120) | 0.000 | 0.102 | 0.000 |
| Respiratory rate, median (IQR) breaths/min | 34 (30–40) | 30 (26–36) | 35 (30–40) | 35 (30–40) | 0.000 | 0.824 | 0.000 |
| Respiratory rate ε breaths/min, n. (%) | 568 (49) | 72 (29) | 374 (55) | 122 (53) | 0.000 | 0.620 | 0.000 |
| pH, median (IQR) | 7.29 (7.20–7.37) | 7.37 (7.28–7.42) | 7.28 (7.20–7.35) | 7.23 (7.13–7.31) | 0.000 | 0.000 | 0.000 |
| pH < 7.35, n. (%) | 862 (69) | 115 (44) | 550 (72) | 197 (87) | 0.000 | 0.000 | 0.000 |
| PaCO2, median (IQR) mmHg | 47 (38–59) | 42 (35–51) | 47 (39–57) | 60 (45–72) | 0.000 | 0.000 | 0.000 |
| PaCO2 ≤ 35 mmHg, n. (%) | 235 (18) | 74 (27) | 136 (17) | 25 (11) | 0.000 | 0.012 | 0.000 |
| PaCO2 ≥ 45 mmHg, n. (%) | 732 (58) | 116 (43) | 440 (57) | 176 (76) | 0.000 | 0.000 | 0.000 |
| PaO2/FiO2 ratio, median (IQR) | 195 (134–247) | 209 (155–252) | 190 (128–248) | 181 (136–243) | 0.119 | 0.623 | 0.056 |
| PaO2/FiO2 ratio < 200, n. (%) | 652 (51) | 116 (43) | 412 (54) | 124 (54) | 0.006 | 0.992 | 0.001 |
| HCO3−, median (IQR) mmol/L | 22 (20–26) | 23 (20–26) | 22 (19–25) | 23 (20–26) | 0.004 | 0.042 | 0.009 |
| HCO3− > 24 mEq/L | 415 (33) | 104 (38) | 226 (30) | 85 (37) | 0.011 | 0.045 | 0.025 |
| Lactates, median (IQR) mmol/L | 2.2 (1.3–3.9) | 2 (1.1–3.1) | 2.3 (1.4–4) | 2.25 (1.2–4) | 0.070 | 0.573 | 0.026 |
| Kelly scale > 3 | 61 (5) | 10 (4) | 27 (3) | 24 (11) | 0.000 | 0.000 | 0.452 |
Footnotes: CPAP continuous positive airway pressure, BiPAP Bi-level Positive Airway Pressure, IQR 25–75 interquartile range, COPD chronic obstructive pulmonary disease, ACPE acute cardiogenic pulmonary edema, PaO2 partial pressure of oxygen in the arterial blood, FiO2 inspiratory fraction of oxygen, PaCO2 partial pressure of carbon dioxide in the arterial blood, HCO3− bicarbonates, *Hypothension was defined as systolic blood pressure < 90 mmHg; +among the three groups; #between CPAP Group vs. BiPAP Group; §between Oxygen Group vs. CPAP plus BiPAP Groups