patients who will undergo elective open nephrectomy will be divided into three groups; the control (PCA), the erector spina plane block, and the quadratus lumborum block. After standard anesthesia induction and monitorization then Bispectral index monitoring will be applied to all patients. Anesthesia will be maintained using sevoflurane in a mixture of oxygen and air. Continuous remifentanil infusion will be used for analgesia. Then patient's numeric rating scales and morphine pca consumptions will be recorded for one day.