Table 2

Results of dynamic CO₂ administration on end-tidal CO₂ and ventilation

	Mean (kPa)		SD/mean		Mean (L/min)		SD/mean
Baseline	4.83±0.58		0.02±0.01		7.8±1.8		0.10±0.03
Untreated	4.84±0.47		0.06±0.01		7.8±1.2		0.19±0.09
p vs baseline		0.90		<0.001		0.6		<0.01
Predicted optimum	4.90±0.45		0.04±0.01		8.4±1.2		0.14±0.06
p vs baseline		0.40		<0.001		0.5		<0.01
p vs untreated		0.1		<0.001		0.2		<0.01
Antiphase to predicted optimum	4.85±0.43		0.06±0.02		7.2±1.8		0.24±0.09
p vs baseline		0.5		0.001		0.2		<0.001
p vs untreated		0.2		0.8		0.30		0.2
p vs optimal		0.2		0		0.1		<0.01

Degree of oscillation and mean end-tidal CO₂ and ventilation when the patients were quietly observed at rest ‘Baseline’, cardiac output was alternated using a pacemaker to induce oscillations ‘Untreated’, dynamic CO₂ was applied to the induced oscillations coincident with peak ventilation ‘Predicted Optimal’, and dynamic CO₂ was applied to the induced oscillations coincident with trough ventilation ‘Antiphase to predicted optimum’.