Table 4: Protocol for systemic heparin administration and adjustment in children.

StageaPTT (sec)Dose (units/kg)Hold (min)Rate change (%)Repeat aPTT

(I) Loading dose75 IV over 10 min
(II) Initial maintenance dose
  Infants < 1 yo28/h
  Children > 1 yo20/h
(III) Adjustment<50500104 h
50–5900104 h
60–85000Next day
86–9500−104 h
96–120030−104 h
>120060−154 h
(IV) Obtain blood for aPTT 4 h after heparin load and 4 h after every infusion rate change
(V) When apt values are in therapeutic range, perform daily CBC and apt measurement

Adapted from Roach et al. [88]