Table 3.

Respiratory variables obtained for 48 h

	All Data (max. 4,032 data points)				Randomly Selected Data (n = 196)
	Data points	% Missing	Mean ± SD	95% CI	Mean ± SD	95% CI
Pneumotachograph (PN) in ventilator
RR-PN, bpm	3,745	7.1	15.5 ± 5.1	15.4–15.7	15.2 ± 5.0	14.5–16.0
TV-PN, L	3,688	8.5	0.46 ± 0.09	0.45–0.46	0.46 ± 0.10	0.44–0.47
MV-PN, L/min	3,688	8.5	6.98 ± 2.36	6.90–7.06	6.80 ± 2.10	6.51–7.10
BSS
RR-BSS, bpm	3,129	22.4*	14.4 ± 4.6	14.3–14.6	14.8 ± 4.9	14.1–15.5
TA-BSS, kg	3,414	15.3*	0.13 ± 0.05	0.12–0.13	0.13 ± 0.05	0.12–0.14
RR-BSS × TA-BSS, kg/min	3,122	22.6	1.80 ± 0.90	1.76–1.83	1.86 ± 0.89	1.73–2.00
Estimated MV-BSS, L/min	3,122	22.6*	6.59 ± 3.31	6.48–6.71	6.82 ± 3.3	6.36–7.29
Impedance pneumography (IP)
RR-IP, bpm	3,857	4.3*	16.2 ± 5.3	16.0–16.4	15.7 ± 5.1	15.0–16.4

bpm, Breaths/min; BSS, bed sensor system ; CI, confidence interval; MV, minute ventilatory volume; PN, RR, respiratory rate; TA, tidal centroid shift amplitude; TV, tidal volume. *P < 0.05 vs. the variables measured by the ventilator.