Nitrogen washout/washin, helium dilution and computed tomography in the assessment of end expiratory lung volume

Table 1 The baseline characteristics of the study population. Plateau pressure, respiratory system compliance and arterial blood gas data were measured during the study, standardised at 5 cmH₂O PEEP.

Characteristics	Value
Age – years	66 ± 10
Female sex – number (%)	9 (30)
BMI – kg/m²	26 ± 8
Tidal volume – ml/kg of predicted body weight	8 ± 1
Minute ventilation – L/minute	7.5 ± 1.8
Respiratory rate – breaths/minute	14 ± 3
Clinical PEEP – cmH₂O	8.3 ± 3.3
Plateau pressure – cmH₂O	19 ± 4
Respiratory system compliance – ml/cmH₂O	43 ± 18
Respiratory system resistance – cmH₂O/L/second	22 ± 9
PaO₂/FiO₂ – mmHg	190 ± 71
FiO₂	0.50 ± 0.13
PaCO₂ – mmHg	41 ± 9
Arterial pH	7.422 ± 0.061
*Cause of lung injury – number*
Pneumonia	6
Sepsis	11
Aspiration	3
Trauma	5
Other	5
*Type of lung injury – number*
ARDS	20
Acute lung injury	7
Other (PaO₂/FiO₂ > 300 mmHg)	3

ARDS = acute respiratory distress syndrome; BMI = body mass index; FiO₂ = inspired oxygen fraction; PaCO₂ = partial arterial pressure of carbon dioxide; PEEP = positive end expiratory pressure.

ISSN: 1364-8535