Table 6—

Arterial blood-gas evolution in the study patients by pathology

Placebo groupBi-level NPPV group
BeforeAfterp-valueBeforeAfterp-value
APO
 Added O2 L·min−17.4±0.89 (6–8)8.2±1.48 (6–10)ns6.6±5.77 (1–10)5.6±2.08 (4–8)NA
 Arterial pH7.24±0.15 (7.08–7.43)7.28±0.16 (7.08–7.48)ns7.25±0.1 (7.1–7.36)7.32±0.02 (7.3–7.35)NA
Pa,CO2 mmHg51±8.3 (45–65)48.6±5.7 (41–56)ns50±7.5 (45–61)37±6.9(29–47)NA
Pa,O2 mmHg62±18.6 (43–89)54±9.4 (43–63)ns89±44 (37–155)89±20 (60–120)NA
Sa,O2 %83.6±10.9 (67.6–96.6)81±11.2 (67.6–91.7)ns84.4±18.1 (64.1–99.1)94.4±5.1 (88.6–98.2)NA
Sp,O2 %75.4±20.1 (50–96)77.2±17.8 (61–96)ns90.6±8.73 (81–98)91.6±11.8 (78–99)NA
COPD
 Added O2 L·min−14±2.74 (1–8)3.2±2.9 (1–8)ns2.6±1.3 (1–3.5)1.1±0.9 (0–2)ns
 Arterial pH7.24±0.09 (7.13–7.32)7.24±0.05 (7.17–7.32)ns7.30±0.05 (7.22–7.39)7.38±0.05 (7.3–7.47)0.002
Pa,CO2 mmHg68.8±23.5 (46–102)64±26.5 (40–107)ns59.1±18.5 (35–9)48±13.4 (32–65)0.03
Pa,O2 mmHg66.2±22.7 (41–92)73.6±38 (35–129)ns73.4±28 (41–127)68.7±21.8 (45–102)ns
Sa,O2 %83.5±14.5 (60.2–96.4)81.4±19.4 (53.3–98.1)ns89.5±8.5 (72.1–98.3)90.4±6.6 (79.6–97.3)ns
Sp,O2 %84±14.7 (58–92)83.2±18.7 (50–94)ns88.4±8.8 (71–97)91.3±3.8 (87–97)ns
  • Data are presented as mean±sd (range)

  • ns: not significant

  • NA: not applicable

  • APO: acute pulmonary oedema

  • COPD: chronic obstructive pulmonary disease

  • 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

  • APO: placebo group n=5

  • bi-level NPPV group n=3

  • COPD: placebo group n=5

  • bi-level NPPV group n=7

  • 1 mmHg=0.133 kpA