Table 2.
Baseline characteristics and outcomes of PMV and non-PMV cases in study population
| n* | |||||
|---|---|---|---|---|---|
| PMV | Non-PMV | PMV | Non-PMV | P value | |
| Age mean (SD) | 349 | 7,499 | 59.6 (15.2) | 56.9 (18.1) | 0.001 |
| Sex n (% female) | 349 | 7,499 | 148 (42.4) | 3,218 (42.9) | 0.86 |
| Days in hospital before ICU admission | <0.001a | ||||
| Mean (SD) | 5.9 (14.0) | 3.5 (11.0) | |||
| Median (IQR) | 1 (0 to 5) | 0 (0 to 2) | |||
| APACHE II score mean (SD) | 307 | 6,659 | 21.0 (6.8) | 18.8 (8.3) | <0.001 |
| CPR in 24 hours before ICU admission n (%) | 349 | 7,499 | 23 (6.6) | 663 (8.8) | 0.15 |
| Number of co-morbidities n (%) | 340 | 7,228 | <0.001a | ||
| None | 276 (81.2) | 5,317 (73.6) | |||
| 1 | 50 (14.7) | 1,211 (16.8) | |||
| 2 or more | 14 (4.1) | 700 (9.7) | |||
| Surgical status n (%) | 347 | 7,463 | <0.001 | ||
| Emergency | 52 (15.0) | 1,747 (23.4) | |||
| Elective | 15 (4.3) | 893 (12.0) | |||
| Non-surgical | 280 (80.7) | 4,823 (64.6) | |||
| Ventilated on day 1 n (%) | 341 | 7,354 | 312 (91.5) | 4,884 (66.4) | <0.001 |
| PaO2:FiO2 ratio (mmHg) | 334 | 6,477 | <0.001 | ||
| Mean (SD) | 155 (82) | 242 (125) | |||
| Median (IQR) | 139 (93 to 201) | 227 (142 to 322) | |||
| Tracheostomy placed during admission n (%) | 349 | 7,499 | 219 (62.8) | 470 (6.3) | <0.001 |
| Five most common admission diagnoses n (%) | 349 | 7,499 | - | ||
| Pneumonia - any cause | 92 (26.4) | 650 (8.7) | |||
| Septic shock - any source | 39 (11.2) | 398 (5.3) | |||
| Trauma | 22 (6.3) | 466 (6.2) | |||
| Gastrointestinal perforation | 18 (5.2) | - | |||
| Pancreatitis | 18 (5.2) | - | |||
| Cardiac arrest | - | 457 (6.1) | |||
| Self-inflicted overdose | - | 401 (5.3) | |||
| Length of ICU stay (days) | 349 | 7,499 | - | ||
| Mean (SD) | 37.2 (16.1) | 3.8 (4.9) | |||
| Median (IQR) | 33 (26 to 44) | 2 (1 to 5) | |||
| Number of days ventilated | 349 | 7,499 | - | ||
| Mean (SD) | 33.2 (14.7) | 2.9 (4.2) | |||
| Median (IQR) | 29 (24 to 38) | 1 (0 to 3) | |||
| Length of hospital stay after ICU discharge (days) | 296 | 6,709 | <0.001a | ||
| Mean (SD) | 35 (49) | 19 (40) | |||
| Median (IQR) | 17 (0 to 45) | 7 (0 to 20) | |||
| Hospital discharge destination of survivors n (%) | 179 | 4,436 | 0.06 | ||
| Normal residence | 160 (89.4) | 4,155 (93.7) | |||
| Rehabilitation unit | 14 (7.8) | 224 (5.0) | |||
| Long-term institutional care | 5 (2.8) | 49 (1.1) | |||
| Hospice or equivalent | 0 (0) | 5 (0.1) | |||
| ICU mortality n (%) | 317 | 7,103 | 83 (26.2) | 1,654 (23.3) | 0.23 |
| Hospital mortality n (%) | 305 | 6,763 | 123 (40.3) | 2,286 (33.8) | 0.02 |
Readmission episodes are excluded (n = 428) for length of hospital stay, hospital discharge destination, ICU mortality and hospital mortality. *Due to missing data, n is stated for each variable. aMann-Whitney U test.
APACHE, Acute Physiology and Chronic Health Evaluation; CPR, cardiopulmonary resuscitation; FiO2, fraction of inspired oxygen; IQR, interquartile range; PaO2, partial pressure of arterial oxygen in mmHg; PMV, prolonged mechanical ventilation; SD, standard deviation.