To compare between caudal block and ultrasound guided Quadratus Lamborum block in reducing postoperative pain, opioid consumption, and recovery time following elective inguinal herniorraphy.

The primary outcome:

• to compare between caudal block and ultrasound guided quadratus lamborum block.

The secondary outcome:

• duration of postoperative analgesia.
• incidence of postoperative complications.

After approval of Ethics Committee of the Faculty of Medicine, and taking a written informed consent from the guardians of each patient, the present study will be carried out in Alexandria Main University Hospitals on 60 patients , aged 2 to 5 years and American Society of Anaesthesiologists (ASA) physical status I or II who will be scheduled for elective inguinal herniorraphy in a randomized double blinded study.

The sample size was calculated by High Institute of Public Health.

Exclusion Criteria:

Infection at the site of needle insertion Neuromuscular disease/damage Anticoagulation or bleeding disorder. Sepsis Allergy to local anaesthetics. Guardians refusal

The patients will be randomly divided by closed envelope technique into two groups:

Group I: 30 patients will receive a caudal block after induction of general anaesthesia.

Group II::Will receive ultrasound guided quadrates lumborum block (QL ) ( posterior transmuscular approach ) using 0.5 mL/kg 0.25% bupivacaine to be applied between the QL muscles and the thoracolumbar fascia. .

METHOD

Preoperative Assessment:

1. History taking
2. Clinical examination
3. Routine laboratory investigations including complete blood picture, bleeding and clotting time, prothrombin time, partial thromboplastin time, blood urea, serum creatinine and fasting blood sugar will be done to every patient.

Pre anaesthetic preparation and premedication

• Nothing per mouth for 6 hours before surgery.
• A peripheral cannula (22 G) will be inserted in all patients.
• Administration 0f 10ml/kg. lactated Ringer's solution.
• All patients will be premedicated with atropine 0,1mg/kg. administered IM to all the patients 30 min prior to surgery.

A multi-channel monitor will be attached to the patient to display:

1. Continuous lead II electro cardiogram (ECG) monitoring.
2. Non-invasive blood pressure measurement (NIBP) mmHg.
3. Arterial oxygen saturation by pulse oximeter (SpO2%).
4. End-tidal capnogram (ETco2).

Induction of anesthesia General anesthesia will be induced with sevoflurane and 50% air in oxygen then IV access will be inserted . Fentanyl will be administered at 1 μg/kg, and a laryngeal mask airway will be used to secure the upper airway. Anaesthesia will be maintained with sevoflurane 2% and 50% air in oxygen.

• All procedures (Caudal , QL) will be performed by the same anaesthetist after placement of the LMA before surgery.
• The patients of both groups were admitted to the ward and receive standard postoperative analgesic regimen composed of regular paracetamol 15mg./kg. every 8hours.

According to the studied group, patients will receive after induction either Group I: caudal block. Group II: Quadratus lamborum block.

Technique:

-For the caudal block, the patients were first inducted by GA and then they were placed in the altered left lateral position. The block site, which was mainly at the sacral hiatus, was sterilized with betadine, and the sacral hiatus between the sacral conui was palpated. Then a 23-gage short needle injection was used with the bevel towards the abdomen to puncture the sacral surface at a 45-degree angle. When the sacrococcygeal ligament seemed to have punctured, the needle was tilted more towards the skin surface and the needle was inserted 2-3 mm deeper. The needle was aspired to check for blood and cerebral spinal fluid extravasations. The loss of resistance was confirmed with air-infusion. Then 0.25% bupivacaine 1 ml/kg was infused. (8,9).

In the QL block group, the probe will be placed anterior and superior to the iliac crest, and the 3 abdominal wall muscles will be visualized. The external abdominal oblique muscle will be followed posterolaterally until the posterior border of the muscle will be identified. When the probe is tilted to the attachment site of both the internal abdominal oblique muscle and the external abdominal oblique muscle over the QL, the midline of the thoracolumbar fascia will be seen as a bright hyperechogenic line. A 22-gauge 80-mm Quincke-type SonoPlex needle (Pajunk, Geisingen,Germany) will be inserted using an in-plane technique. The needle will be directed from anterolateral to posteromedial after making a negative aspiration test with 0.5 mL normal saline to confirm the space with a hypoechoic image and hydrodissection. An injection of 0.5 mL/kg 0.25% bupivacaine will be applied between the QL muscles and the thoracolumbar fascia(10).

The operation will be planned to begin 7 to 10 minutes after the block is applied , and all patients will be operated on with a standardized technique.

Pain levels will be assessed using a FLACC(11) (Face, Legs, Activity, Cry, Consolability ) behavioral pain assessment scale postoperatively . When the FLACC score is 4 or greater ibuprofen 7mg/kg will be administered orally .

Any complications occurring during the procedure will be recorded and treated :

• Hypotension : In childhood, hypotension can be considered significant when there is 20-30% reduction from baseline in systolic blood pressure ( SBP ) (12) . Treated by administering fluid bolus(13) .
• Bradycardia : Defined as(14):

< 60 bpm in kids 3-7 years old . Treated by 0.01-0.02 mg/kg atropine .

• Nausea and vomiting treated with ondansetron 0.1mg/kg intravenously(15) .

MEASURMENTS:

The following parameters will be measured for all patients:

• Pain levels will be assessed using a FLACC (Face, Legs ,Activity, Cry, Consolability) behavioral pain assessment scale postoperatively after recovery at 30minutes and at 1, 2, 4, 6, 12, and24 hours by the nurses and a second anesthetist will be blinded to groupassignment in the recovery room and the surgical ward .
• Duration of analgesia measured by time from start of the block to the first request for analgesia .
• Total analgesic dose .
• Postoperative complications, such as hypotension, arrhythmia, bradycardia,, nausea, or vomiting .
• Parent satisfaction. Satisfaction levels of the parents will be given verbally as a level from 1 to 10, with the lowest level of satisfaction at a value of 1 and the highest level at 10(16).

A-Haemodynamics

1. Heart rate (beats/minute) and rhythm.

2. Non-invasive mean arterial blood pressure (MABP) in mm Hg. Timing

   • Baseline: before the block.
   • Just after the block.
   • Every 5 min during surgery.
   • Every 2 hour after surgery.

B-Need for intraoperative rescue analgesia:

Adequate intraoperative analgesia was defined by hemodynamic stability, as indicated by the absence of an increase in heart rate or systolic arterial pressure 15% compared with baseline values obtained just before surgical incision. An intraoperative increase in blood pressure (BP) or heart rate (HR) by 15% was defined as insufficient analgesia and was treated with a rescue opioid (fentanyl; 1mcg/kg).

C-Assessment of Postoperative analgesia For postoperative pain evaluation, the pain scores were measured and the facial pain scores were taken 10 min, 30 min and 60 min upon arriving into the PACU. The patients were moved to their wards after 90 min passed in the PACU. At 120 min. post-surgery, the last pain scores were taken. The pain scores were taken when the patient was not crying. If the pain score was over 0.6, then paracetamol 15 mg/kg was infused.

D-Analgesic requirements

• Total dose of analgesics postoperative will be recorded
• Time of first analgesic dose given. E-Incidence of postoperative complications: e.g.: nausea , vomiting and respiratory depression.

Inclusion Criteria: Patients , aged 2 to 5 years and American Society of Anaesthesiologists (ASA) physical status I or II who will be scheduled for elective inguinal herniorraphy in a randomized double blinded study.

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Exclusion Criteria:

Infection at the site of needle insertion Neuromuscular disease/damage Anticoagulation or bleeding disorder. Sepsis Allergy to local anaesthetics. Guardians refusal