Demographics and admission characteristics of pertussis-related intensive care unit (ICU) admissions, 1997–2013
| Year of admission | 1997–2000 | 2001–2004 | 2005–2008 | 2009–2012 | 2013* | Total |
|---|---|---|---|---|---|---|
| Number of participating ICUs† | 7–9 | 9–14 | 13–19 | 19–20 | 21 | 7–21 |
| Pertussis-related admissions N (per cent of total pertussis admissions) | 47 (12.6) | 66 (17.7) | 45 (12.1) | 197 (52.8) | 18 (4.8) | 373 (100) |
| Pertussis-related ICU admissions per 1000 all-cause ICU admissions (total all-cause ICU admissions) | 2.2 (21 263) | 2.7 (24 636) | 1.6 (27 385) | 6.4 (30 954) | 1.9 (9232) | 3.3 (113 197) |
| Sex Male—N (%) | 25 (54.3) | 41 (62.1) | 22 (48.9) | 85 (43.2) | 9 (50.0) | 182 (48.9) |
| Ethnicity Aboriginal and Torres Strait Islander peoples—number with ethnicity recorded (%) | 5 of 46 (10.9) | 8 of 66 (12.1) | 1 of 16 (6.3) | 4 of 45 (8.9) | 0 of 10 (0) | 18 of 183 (9.8) |
| Age | ||||||
| <6 weeks | 24 (51.1%) | 25 (38.9%) | 12 (26.7%) | 87 (44.2%) | 8 (44.4%) | 156 (41.8%) |
| 6 weeks to<4 months | 21 (44.7%) | 35 (53.0%) | 23 (51.1%) | 72 (36.6%) | 9 (50.0%) | 160 (42.9%) |
| 4 to <6 months | 2 (4.3%) | 0 (0%) | 2 (4.4%) | 10 (5.1%) | 0 (0%) | 14 (3.8%) |
| 6 months to <1 year | 0 (0%) | 2 (3.0%) | 4 (8.9%) | 9 (4.6%) | 0 (0%) | 15 (4.0%) |
| ≥1 year | 0 (0%) | 4 (6.1%) | 4 (8.9%) | 19 (9.6%) | 1 (5.6%) | 28 (7.5%) |
| Median age (range) | 42 days (17 to 152 days) | 49 days (19 days to 14.6 years) | 62 days (4 days to 15.2 years) | 48 days (0 days to 15.9 years) | 45.5 days (23 days to 8.4 years) | 48 days (0 days to 15.9 years) |
| Case state/territory of residence‡ N (per cent of total pertussis-related admissions); total all-cause ICU admissions | ||||||
| Australian Capital Territory | 0 (0.0); ND | 0 (0.0); 110 | 0 (0.0); 112 | 1 (0.5); 121 | 0 (0.0); 26 | 1 (0.3); 369 |
| New South Wales | 16 (34.0); 5896 | 11 (17.5); 7217 | 25 (56.8); 8037 | 70 (35.9); 9274 | 4 (22.2); 2526 | 126 (34.3); 32 950 |
| Northern Territory | 1 (2.1); ND | 3 (4.8); ND | 2 (4.5); 222 | 1 (0.5); 243 | 0 (0.0); 83 | 7 (1.9); 548 |
| Queensland | 10 (21.3); 5201 | 11 (17.5); 5697 | 5 (11.4); 7177 | 43 (22.1); 7984 | 2 (11.1); 2843 | 71 (19.3); 28 902 |
| South Australia | 3 (6.4); 2345 | 12 (19.0); 2265 | 4 (9.1); 2170 | 9 (4.6); 2179 | 0 (0.0); 555 | 28 (7.6); 9514 |
| Tasmania | 0 (0.0); 62 | 0 (0.0); 163 | 0 (0.0); 338 | 9 (4.6); 853 | 2 (11.1); 215 | 11 (3.0); 1631 |
| Victoria | 3 (6.4); 4953 | 16 (25.4); 5699 | 5 (11.4); 6272 | 50 (25.6); 7228 | 10 (55.6); 2185 | 84 (22.9); 26 337 |
| Western Australia | 14 (29.8); 2806 | 10 (15.9); 3212 | 3 6.83057 | 12 (6.2); 3072 | 0 (0.0); 799 | 39 (10.6); 12 946 |
| Patients with comorbidities N (%) | 5 (10.6) | 7 (10.6) | 9 (20.0) | 30 (15.2) | 1 (5.6) | 52 (13.9) |
| Patients with infectious agent co-detection N (%) | 5 (10.6) | 7 (10.6) | 14 (31.1) | 38 (19.3) | 1 (5.6) | 65 (17.4) |
| Length of ICU stay Median (range) | 3.6 days (<1–35 days) | 3.7 days (<1–36 days) | 3.6 days (<1–50 days) | 3.4 days (<1–209 days) | 6.1 days (1–11 days) | 3.6 days (<1–209 days) |
| Respiratory support required during 1st hour of ICU admission§¶ N (%) | 16 (34.0) | 22 (33.8) | 21 (46.7) | 67 (34.0) | 7 (38.9) | 133 (35.7) |
| Respiratory support required during ICU admission §¶ N (%) | 20 (46.5) | 27 (46.5) | 19 (63.3) | 107 (58.5) | 9 (50.0) | 182 (54.8) |
| Invasive respiratory support required during ICU admission** N (%) | 17 (36.2) | 27 (40.9) | 23 (51.1) | 52 (26.4) | 3 (16.7) | 122 (32.7) |
| Length of invasive respiratory support ** Median (range) | 3.5 days (5.0 to 31.4 days) | 4.9 days (8.6 h to 32.2 days) | 4.8 days (0.8 h to 40 days) | 3.8 days (1.5 h to 208.6 days) | 6.6 days (2.0 to 7.6 days) | 4.5 days (0.8 h to 208.6 days) |
| Deaths N (%) | 5 (10.6) | 8 (12.1) | 3 (6.7) | 7 (3.1) | 0 (0) | 23 (6.2) |
*Single year of data.
†Number of participating ICUs increased during the time period.
‡Three ICU admissions had no residential state recorded, and three were classified as residing overseas.
§Respiratory support is defined as any intervention to support respiratory function, and includes both non-invasive and invasive methods. Some patients may have required combinations of both invasive and non-invasive support during their ICU admission. Non-invasive respiratory support includes: continuous positive airway pressure, biphasic positive airway pressure, negative pressure ventilation and high-flow nasal cannula.
¶Respiratory support during 1st hour; data were missing for 161 cases. Respiratory support during admission data were missing for 41 cases.
**Invasive respiratory support is mechanical ventilation delivered by endotracheal intubation or tracheostomy.
ND, no ICUs contributing to ANZPIC Registry during this time period (cases treated interstate).