Does taking endurance into account improve the prediction of weaning outcome in mechanically ventilated children?

Table 1 Index formulas

Index [reference]	Definition	Formula
RSB_p [13]	Paediatric rapid shallow breathing	RR_s/VT_s
ROP [26]	Rapid shallow breathing occlusion pressure	= P_0.1 × (RR_s/VT_s)
PTI [28]^a,b	Pressure–time index	= (P_breath/Pi_max) × (T_i/T_tot) P_breath = (PIP - PEP)/(VT_s/VT_PSV)
TTI₁ [37,38]	Tension–time index 1	= (P_imoy/Pi_max) × (T_i/T_tot) P_imoy = 0.5 × (P_0.1 × 10) × T_i
TTI₂ [39]	Tension–time index 2	= (P_aw/Pi_max) × (T_i/T_tot)

^aPaediatric literature; ^badult literature. P_0.1, negative pressure 0.1 s after airway occlusion (cmH₂O); P_aw, mean airway pressure on pressure support ventilation (cmH₂O); P_breath, pressure generated by unassisted breath (cmH₂O); PEEP, positive end-expiratory pressure on pressure support ventilation (cmH₂O); PIP, peak inspiratory pressure on pressure support ventilation (cmH₂O); Pi_max, maximal inspiratory pressure during occlusion test (cmH₂O); P_imoy, spontaneous mean inspiratory airway pressure (cmH₂O); PTI, pressure–time index (no unit); ROP, rapid shallow breathing occlusion pressure (cmH₂O/breaths per min per ml); RR_s, spontaneous respiratory rate (breaths/min); RSBp, paediatric rapid shallow breathing (breaths/min per ml per kg); T_i, inspiratory time (s); T_i/T_tot, inspiratory duty cycle; TTI₁, tension–time index obtained from the P_0.1 value (%); TTI₂, tension–time index obtained from the P_aw value (%); VT_PSV, tidal volume on pressure support ventilation (ml/kg); VT_s, spontaneous tidal volume (ml/kg).

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