Comparison Between the Quadratus Lumborum Block ,Erector Spinae Plane Block in Lower Abdominal Surgery

the study will be performed from November 2021 to January 2023 at Fayoum University hospital after approval of the local institutional ethics committee and local institutional review board .A detailed informed consent will be signed by the eligible participants before recruitment and randomization.

Preoperative preparations and Premedication :•

Both groups will be assessed by history taking, careful examination ,and laboratory investigations like:

Complete blood count (CBC), coagulation profile:(prothrombin concentration(PC),Partial thromboplastin time(PTT),International Normalized Ratio(INR) ) , kidney function, liver function, ECG for patient >40 years old or indicated cases, specific investigations to each disease

.•the investigators will teach the patients Visual Analogue Score (VAS) and train them.

Intra operative technique and management:

When patients reach Theater, standard American Society of Anesthesiology(ASA) monitoring by (noninvasive blood pressure (NIBP), pulse oximetry, electrocardiography, and capnography) will be applied.

the investigators will allocate basal data for each patient like: heart rate (HR), systolic and diastolic blood pressure, mean arterial blood pressure and arterial oxygen saturation will be recorded. Intravenous cannulation (IV) and intravenous fluid will be started. Intravenous Midazolam 0.03-0.05 mg/kg will be administered to all patients as premedication, Then the patients undergoing general anesthesia, At the first pre-oxygenation with O2100% for at least 3-5 min then the investigators will start Induction of anesthesia for both groups, general anesthesia will be induced with intravenous injection of fentanyl (1-2 µg/kg) and propofol (1, 5 - 2 mg/kg), and then atracurium (0.5 mg/kg) will be injected for endotracheal intubation. Mechanical ventilation will be maintained by controlled mechanical ventilation (CMV) mode with tidal volume ( 6-8ml /kg) with oxygen and air (50:50) with target of EtCo2≈ 30-40 mmHg, anesthesia will be maintained with isoflurane 1%-2% , Incremental dose of atracurium (0.1 mg/kg) will be given every 20 min or when needed. In addition, 0.5μg/kg fentanyl will be given intraoperatively once needed (increase of heart rate or NIBP more than 20% of the basal records) After endotracheal intubation and finishing the operation before awakening of patients the anesthesiologist will perform either the (QL) block technique or the (ESPB) block technique.

Statistical analysis:

The collected data will be organized, tabulated and statistically analyzed using SPSS software statistical computer package version 22 (SPSS Inc, USA). For quantitative data, the mean and standard deviation (SD) or median and interquartile range will be calculated. Independent-t test or Mann-Whitney U test, when appropriate, will be used as a test of significance. Qualitative data will be presented as number and percentages, chi square (χ2) will be used as a test of significance. For interpretation of results of tests of significance, significance will be adopted at P ≤ 0.05.

Sample size was calculated using (G power version 3). Minimal sample size of patients was 20 in each group needed to get power level 0.90, alpha level 0.05 (two tailed) and effect size of 1.08 for the overall dose of morphine. To overcome problem of loss of follow up, calculated sample size was increased by 20% to reach 24 in each group.