Demographic characteristics of patients admitted with community-acquired pneumonia
| Normocapnia (PaCO2 35–45 mm Hg) | Hypocapnia (PaCO2 <35 mm Hg) | Hypercapnia (PaCO2 >45 mm Hg) | p Value | |
| Total patients (n=295) | 57 (19.32%) | 181 (61.35%) | 57 (19.32%) | |
| Mean age (years) | 61.14±13.85 | 58.18±18.97 | 65.77±11.37 | 0.18 |
| Gender | ||||
| Men | 18 (31.57%) | 108 (59.66%) | 31 (54.38%) | 0.08 |
| Women | 39 (68.42%) | 73 (40.33%) | 26 (45.61%) | |
| Season | ||||
| January to April | 24 (42.1%) | 53 (29.3%) | 34 (59.6%) | 0.001 |
| May to August | 14 (24.6%) | 57 (31.5%) | 8 (14%) | |
| September to December | 19 (33.3%) | 71 (39.2%) | 15 (26.3%) | |
| Comorbid Diabetes | 23 (40.35%) | 50 (27.62%) | 25 (43.9%) | 0.03 |
| IHD | 18 (31.57%) | 33 (18.23%) | 14 (24.6%) | 0.04 |
| HTN | 27 (47.4%) | 68 (37.6%) | 27 (47.4%) | 0.25 |
| COPD | 0 | 4 (2.2%) | 11 (19.3%) | <0.001 |
| Asthma | 3 (5.3%) | 25 (13.8%) | 10 (17.5%) | 0.12 |
| pH | ||||
| <7.35 | 5 (8.7%) | 8 (4.4%) | 35 (61.40%) | <0.001 |
| >7.35 | 52 (91.22%) | 173 (95.58%) | 22 (38.59%) | |
| PaO2 level (mean) | 69.13±17.98 | 71.68±20.16 | 78.45±35 | 0.37 |
| PaCO2 level (mean) | 37.05±3.65 | 30.66±9.54 | 65.36±18.94 | <0.001 |
| Serum creatinine | ||||
| <1 | 36 (63.15%) | 59 (32.59%) | 15 (26.31%) | 0.01 |
| >1 | 21 (36.84%) | 122 (67.40%) | 42 (73.68%) | |
| CURB65 (mean±SD) | 2.0±1.06 | 2.37±1.14 | 3.14±1.28 | 0.004 |
| PSI (mean±SD) | 66.36±32.4 | 72.39±29.46 | 95.68±29.12 | 0.002 |
| Chest X-ray infiltrates | ||||
| Unilateral | 35 (61.4%) | 118 (65.2%) | 26 (45.6%) | 0.03 |
| Bilateral | 22 (38.6%) | 63 (34.8%) | 31 (54.4%) | |
| Use of steroids (systemic) | ||||
| Yes | 27 (47.4%) | 73 (40.3%) | 42 (73.7%) | <0.001 |
| 30 (52.6%) | 108 (59.7%) | 15 (26.3%) | ||
| NIMV therapy | ||||
| ER | 15 (26.3%) | 112 (61.8%) | 50 (87.71%) | 0.03 |
| SCU | 15 (24.5%) | 94 (51.93%) | 45 (78.94%) | |
| ICU | 0 | 0 | 0 | |
| NIMV failure in ER | 0 | 18 (9.9%) | 5 (8.7%) | |
| TCS (mean±SD), days | 2.76±2.1 | 3.17±1.99 | 4.39±2.0 | 0.03 |
COPD, chronic obstructive pulmonary disease; ER, emergency room; HTN, hypertension; IHD, ischaemic heart disease; NIMV, non-invasive mechanical failure; PSI, pneumonia severity index ; SCU , special care unit TCS, time to clinical stability.