Table 4—

Arterial blood-gas evolution in the study patients

Bi-level NPPVp-valuePlacebo NPPVAfter rescue bi-level NPPVp-value
BeforeAfterBeforeAfter
Added O2 L·min−13.8±3.5 (1–10)2.5±2.5 (1–8)ns5.7±2.6 (1–8)5.7±3.4 (1–10)4.9±3.6 (1–11)ns
Arterial pH7.28±0.08 (7.1–7.39)7.36±0.05 (7.3–7.47)0.017.24±0.11 (7.08–7.43)7.26±0.12 (7.08–7.48)7.35±0.10 (7.19–7.56)0.002
Pa,CO2 mmHg56.3±16.5 (35–93)44.3±12.9 (29–65)0.0159.9±19 (45–102)56.4±19.8 (43–107)46.5±17 (29–91)<0.001
Pa,O2 mmHg78.3±37.2 (37–155)75±24.8 (45–120)ns64.2±19.7 (41–92)63.9±28 (43–129)93±31.8 (61–155)0.02
Sa,O2 %88±11.3 (64.1–99.1)91.6±6.2 (79.6–98.2)ns83.5±12.1 (60.2–96.6)81.2±14.9 (53.3–98.1)94.9±3.7 (89–99.2)<0.01
Sp,O2 %89.1±8.3 (71–98)91.4±6.4 (78–99)ns79.7±17.2 (50–96)80.2±17.5 (50–96)93.3±4.7 (86–98)0.01
  • Data are presented as mean±sd (range)

  • ns: not significant

  • O2: oxygen

  • Pa,CO2: carbon dioxide tension in arterial blood

  • Pa,O2: oxygen tension in arterial blood

  • Sa,O2: arterial oxygen saturation

  • Sp,O2 transcutaneous Sa,O2 measured from a pulse oxymeter with a finger probe

  • NPPV: noninvasive positive-pressure ventilation

  • Bi-level NPPV and Placebo group n=10

  • 1 mmHg=0.133 kpA