Table 1

Comparison of four tools (developed elsewhere) available for withdrawing mechanical ventilation from patients following cardiac surgery showing both the variability between decision support tools and the inexplicit nature of most of them

	Clinical practice guideline	Clinical or critical path	Nursing care plan	Computer protocol
The first column contains the author's questions for each of the available products.
Assess when?				Assess 8 hours after surgery
Aim where?	Stable heart rhythm and haemodynamics, Pao₂ >60, Fio₂ <0.5, positive end expiratory pressure ≤5		Assess pulmonary status	pH >7.3 and spontaneous respiratory rate <30, tidal volume >4 ml/kg, and maximum inspiratory pressure <–30
Achieve what?		Extubation within 24 hours		Spontaneous breathing through a “T” piece with arterial blood gases within 15 minutes