Table 1 Comparison of patients according to the presence or not of hypercapnia at admission
Non-hypercapnic, N = 56 | Hypercapnic, N = 56 | P value | |
|---|---|---|---|
Characteristics of the patients | |||
Age, years | 68.7 ± 14.0 | 76.6 ± 11.8 | <0.01 |
Male gender, n (%) | 26 (46 %) | 30 (54 %) | 0.71 |
SAPS II, points | 36.5 ± 12.5 | 39.1 ± 14.1 | 0.38 |
BMI, kg/m2 | 24.7 ± 6.1 | 27.0 ± 5.6 | 0.03 |
BMI >30 kg/m2, n (%) | 4/47 (9 %) | 14/45 (31 %) | <0.01 |
History of smoking, n (%) | 16 (29 %) | 24 (43 %) | 0.17 |
Underlying ischemic cardiopathy, n (%) | 30 (54 %) | 25 (45 %) | 0.35 |
Baseline LVEF, % | 41 ± 15 | 42 ± 12 | 0.84 |
Reason for CPE | |||
Atrial fibrillation, n (%) | 7 (12.5) | 4 (7.1 %) | 0.52 |
Acute myocardial infarction, n (%) | 3 (5.4 %) | 5 (8.9 %) | 0.71 |
Hypertensive crisis, n (%) | 8 (14.3) | 6 (10.7 %) | 0.77 |
Fluid overload, n (%) | 17 (30.4 %) | 9 (16.1 %) | 0.12 |
Respiratory tract infection, n (%) | 3 (5.4 %) | 11 (19.6 %) | 0.04 |
Unidentified factor, n (%) | 10 (17.9 %) | 14 (25.0) | 0.49 |
Other, n (%) | 8 (14.3 %) | 7 (12.5 %) | >0.99 |
At admission | |||
Respiratory rate, cycles/min | 32 ± 7 | 32 ± 7 | 0.77 |
Heart rate, beats/min | 109 ± 28 | 96 ± 20 | <0.01 |
Systolic blood pressure, mmHg | 151 ± 35 | 157 ± 36 | 0.33 |
Glasgow coma scale, points | 14.8 ± 0.7 | 14.0 ± 2.5 | 0.08 |
pH, units | 7.40 ± 0.06 | 7.25 ± 0.10 | <0.01 |
pH <7.35, n (%) | 10 (18 %) | 44 (79 %) | <0.01 |
PaO2, mmHg | 87 ± 45 | 120 ± 80 | <0.01 |
PaCO2, mmHg | 36 ± 5 | 63 ± 16 | <0.01 |
Bicarbonates, mmol/L | 23.2 ± 3.8 | 29.0 ± 6.9 | <0.01 |
N-terminal pro-BNP, ng/L | 20720 ± 36085 | 23,003 ± 39,928 | 0.59 |
Troponin, μg/L | 0.296 ± 1.053 | 0.207 ± 0.925 | 0.11 |
At initiation of NIV | |||
Respiratory rate, cycles/min | 30 ± 7 | 30 ± 8 | 0.98 |
Heart rate, beats/min | 105 ± 24 | 93 ± 20 | 0.01 |
Systolic blood pressure, mmHg | 136 ± 25 | 144 ± 34 | 0.22 |
Altered consciousness (RASS<0), n (%) | 2 (4 %) | 11 (20 %) | 0.02 |
FiO2, % | 67 ± 24 | 60 ± 27 | 0.21 |
PEEP level, cm H2O | 4.9 ± 1.7 | 4.6 ± 1.8 | 0.35 |
Pressure-support level, cm H2O | 7.9 ± 1.8 | 10.0 ± 2.7 | <0.01 |
Expiratory tidal volume, ml | 604 ± 172 | 496 ± 125 | <0.01 |
pH, units | 7.42 ± 0.09 | 7.35 ± 0.08 | <0.01 |
Minute ventilation, L/min | 17.6 ± 6.0 | 14.5 ± 5.4 | 0.02 |
PaCO2, mmHg | 37 ± 9 | 51 ± 13 | <0.01 |
PaO2/FiO2, mmHg | 247 ± 108 | 234 ± 88 | 0.68 |
Leaks or poor tolerance, n (%) | 5/43 (19 %) | 10/41 (15 %) | 0.16 |
Patients’ outcome | |||
NIV duration, days | 1.0 [1.0–2.0] | 2.0 [1.0–3.0] | 0.14 |
ICU Length of stay, days | 4.0 [2.8–6.0] | 4.0 [2.8–6.3] | 0.97 |
Non-rapid favorable outcome, n (%) | 13 (23.2 %) | 18 (32.1 %) | 0.40 |
Prolonged NIV (>48 h), n (%) | 9 (16.1 %) | 15 (26.8 %) | 0.25 |
Intubation, n (%) | 4 (7.1 %) | 3 (5.4 %) | >0.99 |
In-ICU mortality, n (%) | 2 (3.6 %) | 2 (3.6 %) | >0.99 |