A parturient woman has been in labor for 8 hours. The labor activity is weak, contractions last for 25 seconds and occur twice per 10 minutes. Vaginal examination shows cervical opening of 4 cm, the baby is in the cephalic presentation. During examination the woman's waters broke. The waters contained meconium. Fetal heart rate is 90/min., dull. What tactics of labor management must be chosen in this case?