Table 1

Comparison of patient’s characteristics by time to NIV across the two audits period 2008 and 2014

Variable<60 min60–179 min180–1400 min24 hoursP value<60 min60–179 min180–1400 min>24 hoursP value
n (%)n (%)n (%)n (%)n (%)n (%)n (%)n (%)
249 (24.1)267 (25.9)323 (31.3)193 (18.7)249 (20.9)256 (21.5)465 (39.0)221 (18.6)
First ABGs<0.0010.734
 No0 (0)0 (0)3 (0.9)9 (4.8)1 (0.4)3 (1.2)5 (1.1)3 (1.4)
 Yes249 (100)265 (100)320 (99.1)180 (95.2)248 (99.6)253 (98.8)460 (98.9)218 (98.6)
First ABGs result, mean (SD)
 pH7.2 (0.1)7.3 (0.1)7.3 (0.1)7.4 (0.1)<0.0017.2 (0.1)7.3 (0.1)7.3 (0.1)7.4 (0.1)<0.001
 PCO211 (3.3)10 (2.7)9.1 (2.7)7.3 (2)<0.00110.8 (3.4)10.4 (3)9 (2.4)7.8 (2.6)<0.001
 PO212.3 (8.7)11.7 (7.9)10.4 (6.2)9.7 (5)<0.0019.8 (5.5)9.3 (5)9 (4.8)9 (4)<0.001
 HCO229.9 (7.3)30.4 (7)30.4 (7)29.7 (5.9)0.67629.9 (7)30.4 (7.3)30.1 (6.1)29.7 (6.8)0.168
Second ABGs<0.0010.399
 No11 (5)5 (2)24 (8.2)28 (19.7)9 (3.6)6 (2.3)20 (4.3)5 (2.3)
 Yes211 (95)245 (98)270 (91.8)114 (80.3)240 (96.4)250 (97.7)445 (95.7)216 (97.7)
Second ABGs result, mean (SD)
 pH7.3 (0.1)7.3 (0.1)7.3 (0.1)7.3 (0.1)<0.0017.3 (0.1)7.3 (0.1)7.3 (0.1)7.3 (0.1)<0.001
 PCO29.7 (2.9)9.4 (2.4)9.1 (2.5)8.9 (2.4)0.0389.4 (3)9.6 (2.7)9 (2.4)8.7 (2.3)<0.001
 PO210 (5.4)9.7 (5.1)9.1 (3.8)8.4 (2.7)0.0129.1 (4.8)8.9 (4.5)8.4 (2.9)8.7 (3.8)0.19
 HCO329.5 (7.2)30.3 (7.2)30.2 (7.4)30.6 (6.7)0.5729.6 (6.6)30 (6.4)29.6 (6.3)29.9 (7.4)0.796
Other significant condition0.9170.854
 No57 (23.6)63 (24.1)72 (22.6)41 (21.5)38 (15.3)42 (16.4)82 (17.6)35 (15.8)
 Yes185 (76.4)198 (75.9)246 (77.4)150 (78.5)211 (84.7)214 (83.6)383 (82.4)186 (84.2)
Inpatient death<0.001<0.001
 No203 (81.5)218 (81.6)244 (75.5)110 (57)220 (88.4)223 (87.1)395 (84.9)147 (66.5)
 Yes46 (18.5)49 (18.4)79 (24.5)83 (43)29 (11.6)33 (12.9)70 (15.1)74 (33.5)
  • ABGs, arterial blood gases; NIV, non-invasive ventilation.