Table 2.
Demographics of hypercapnic respiratory failure participants by 30-day readmission status
| All (n = 181) | Not readmitted within 30 days (n = 140, 77%) | Readmitted within 30 days (n = 41, 23%) | p | |
|---|---|---|---|---|
| Female | 100 (55%) | 78 (56%) | 22 (54%) | 0.859 |
| Age (years) | 62.3 ± 15.3 | 62.3 ± 14.2 | 62.5 ± 18.8 | 0.451 |
| BMI (kg/m2) | 36.6 ± 14.4 | 37.4 ± 15.2 | 33.7 ± 10.8 | 0.250 |
| Active smoker | 58 (32%) | 51 (36%) | 7 (17%) | 0.022 |
| Length of admission (M ± SD) (days) | 9.6 ± 13.9 | 9.6 ± 14.1 | 9.8 ± 13.4 | 0.766 |
| ICU admission | ||||
| ICU admission | 103 (57%) | 84 (60%) | 19 (46%) | 0.151 |
| More than one ICU admissiona | 15 (15%) | 10 (12%) | 5 (26%) | 0.146 |
| Intubationa | 49 (48%) | 43 (51%) | 6 (32%) | 0.136 |
| Primary admission reason | ||||
| Respiratory failure | 90 (50%) | 74 (53%) | 16 (39%) | 0.155 |
| Pneumonia | 18 (10%) | 15 (11%) | 3 (7%) | 0.767 |
| COPD exacerbation | 43 (24%) | 35 (25%) | 8 (20%) | 0.537 |
| Overdose | 10 (5%) | 10 (7%) | 0 | 0.120 |
| Sepsis | 23 (13%) | 20 (14%) | 3 (7%) | 0.296 |
| Trauma | 3 (2%) | 2 (1%) | 1 (2%) | 0.539 |
| Cardiac disease | 52 (29%) | 36 (26%) | 16 (39%) | 0.117 |
| Comorbidities | ||||
| Myocardial infarction | 23 (13%) | 17 (12%) | 6 (15%) | 0.790 |
| Congestive heart failure | 54 (30%) | 41 (29%) | 13 (32%) | 0.846 |
| Peripheral vascular disease | 13 (7%) | 6 (4%) | 7 (17%) | 0.011 |
| Cerebrovascular disease | 10 (5%) | 8 (6%) | 2 (5%) | 1.000 |
| Dementia | 1 (1%) | 1 (1%) | 0 | 1.000 |
| Diabetes without chronic complications | 28 (15%) | 19 (14%) | 9 (22%) | 0.221 |
| Renal disease | 35 (19%) | 27 (19%) | 8 (20%) | 1.000 |
| Pulmonary disease | ||||
| COPD | 85 (47%) | 71 (51%) | 14 (34%) | 0.076 |
| Obstructive sleep apnea | 45 (25%) | 36 (26%) | 9 (22%) | 0.686 |
| Obesity hypoventilation | 12 (7%) | 11 (8%) | 1 (2%) | 0.303 |
| Asthma | 21 (12%) | 17 (12%) | 4 (10%) | 0.788 |
| Interstitial lung disease | 4 (2%) | 1 (1%) | 3 (7%) | 0.037 |
| Bronchiectasis (including CF) | 3 (2%) | 0 | 3 (7%) | 0.011 |
| Home respiratory support | ||||
| CPAP | 22 (12%) | 17 (12%) | 5 (12%) | 1.000 |
| BIPAP | 16 (9%) | 13 (9%) | 3 (7%) | 1.000 |
| Oxygen | 69 (38%) | 55 (39%) | 14 (34%) | 0.588 |
| None | 95 (52%) | 70 (50%) | 25 (61%) | 0.286 |
| Charlson comorbidity indexb | 2.0 ± 1.6 | 2.1 ± 1.6 | 1.8 ± 1.5 | 0.224 |
| Discharge respiratory support | ||||
| CPAP | 12 (7%) | 8 (6%) | 4 (10%) | 0.473 |
| BIPAP | 22 (12%) | 19 (14%) | 3 (7%) | 0.416 |
| Oxygen | 73 (40%) | 57 (41%) | 16 (39%) | 1.000 |
| None | 86 (47%) | 65 (46%) | 21 (51%) | 0.599 |
| Admission or death due to hypercapnic respiratory failure | ||||
| Yes | 115 (63%) | 90 (64%) | 25 (61%) | 0.756 |
| No | 37 (20%) | 27 (19%) | 10 (24%) | |
| Maybe | 27 (15%) | 21 (15%) | 6 (15%) | |
| Readmission due to hypercapnic respiratory failure | ||||
| Yes | 66 (36%) | 39 (28%) | 27 (66%) | < 0.001 |
| No | 31 (17%) | 21 (15%) | 10 (24%) | |
| Maybe | 9 (5%) | 5 (4%) | 4 (10%) | |
| Deceased during study period | 68 (38%) | 45 (32%) | 23 (56%) | 0.010 |
| Arterial blood gas valuesc | ||||
| 59.9 ± 22.9 | 60.8 ± 24.2 | 55.5 ± 15.1 | 0.570 | |
| Bicarbonate | ||||
| < 15 | 1 (1%) | 1 (1%) | 0 | 0.289 |
| 15–19 | 8 (4%) | 5 (4%) | 3 (7%) | |
| 20–29 | 84 (46%) | 65 (46%) | 19 (46%) | |
| 30–39 | 69 (38%) | 51 (36%) | 18 (44%) | |
| 40–49 | 10 (6%) | 10 (7%) | 0 | |
| Hemodynamics in first 24 h | ||||
| Most extreme heart rate in first 24 h | ||||
| < 40 | 1 (1%) | 0 | 1 (2%) | 0.017 |
| 40–69 | 21 (12%) | 14 (10%) | 7 (17%) | |
| 70–119 | 123 (68%) | 101 (72%) | 22 (54%) | |
| 120–159 | 27 (15%) | 16 (11%) | 11 (27%) | |
| ≥ 160 | 3 (2%) | 3 (2%) | 0 | |
| Lowest blood pressure | ||||
| MAP ≥ 70 | 137 (76%) | 105 (75%) | 32 (78%) | 1.000 |
| MAP < 70 | 32 (18%) | 25 (18%) | 7 (17%) | |
| Low dose vasopressord | 4 (2%) | 3 (2%) | 1 (2%) | |
| High dose vasopressord | 6 (3%) | 5 (4%) | 1 (2%) | |
Bold values indicate statistical significance
Values shown are mean and SD, and number (%). Categorical variables were tested using Fisher’s exact test. Continuous variables were tested using the Wilcoxon rank sum test
aAmong those admitted to the ICU (n = 103)
bBased on Quan et al. [15]
c38–41% Data missing
dLow dose defined as dopamine ≤ 15 or epinephrine ≤ 0.1 or norepinephrine ≤ 0.1 mcg/kg/min, and high dose defined as dopamine > 15 or epinephrine > 0.1 or norepinephrine > 0.1 mcg/kg/min