Results: Reduction of consumption morphine in the tiltration (12.35 ± 4.99 mg in group II, 12.35 ± 5.36 mg in group III with 15.35 ± 5.30 mg in group I), increase the success of tiltration (92.5% in group II, 65% in group III compared with 60% in group I) and a significant reduction in Perfalgan dose used immediately after the tiltration (0.10 ± 0.30 g in group II, 0.32 ± 0.47 g in group III compared 0.35 ± 0.48 g in group I. Conclusions: combination of morphine and the low-dose ketamine in the ratio 1: 1 has good pain relief so reduces the total dose of morphine consumed in the tiltration, thus increases the success of the tiltration and significantly reduced additive analgesic dose with low incidence of complications.