Quadratus Lumborum Block as an Anesthetic Method for Percutaneous Nephrolithotomy

The study aims to investigate the efficacy and safety of QLB, as an anaesthetic method, for patients undergoing PCNL. Adult patients who agree to participate in the study will be included. Uncooperable patients, pregnant woman, active urinary tract infection, uncorrectable coagulation disorder, and those with known allergy to study medication will be excluded. Low dose spinal anaesthesia and Ultrasound-guided QLB will be performed. The success of the procedure, procedure-related complications, Intra- and post-operative hemodynamics, pain score, overall surgeon and patient satisfaction will be evaluated and reported.

Percutaneous nephrolithotomy (PCNL) is used more frequently than open surgery in the treatment of kidney stones as it is performed through a smaller surgical incision. Postoperative complex pain resulting from the renal capsule dilation and nephrostomy-tube-related stress is reported to prolong the recovery time, reduce patient comfort, and increase complication rates. Opioids, which are used for controlling Intra and postoperative pain, have significant side effects. Multi-modal analgesia regimen and regional anaesthesia methods have been reported to decrease the side effects, in addition to providing effective postoperative pain control.

The use of an intraoperative local anaesthetic or peripheral blocks as an analgesic has been reported for pain control in PCNL but only as analgesia not anaesthesia except loco-regional like spinal and epidural anaesthesia with limitation of time or cardiopulmonary side effects that usually in favour of general anaesthesia that is usually considered the most convenient and prudent way for providing anaesthesia for this operation in spite of its drawbacks.

The quadratus lumborum muscle block (QLB) was first described by Blanco in 2007 as a local anaesthetic injection into the anterolateral junction of the quadratus lumborum muscle (QLB type 1). QLB does not only stop somatic pain but also it inhibits visceral pain due to the spread of the local anaesthetic to the paravertebral space.

Some modifications of this technique were subsequently introduced: injection into the posterior segment of the quadratus lumborum muscle (QLB type2), injection between the quadratus lumborum muscle and the fascia of the psoas muscle using the trans muscular approach (QLB type 3), and injection into the quadratus lumborum muscle (QLB type 4) itself. It is evident that this block is effective in providing analgesia from T7 to L1 dermatomes, it is not only providing analgesia from the anterior abdominal wall but also it can reduce visceral pain.

Although the efficacy of QLB in abdominal surgery has been demonstrated in the literature, its use as an anaesthesia technique not ever reported.

In this study, the investigators introduce a new protocol in providing anaesthesia mainly by fascial peripheral block. It is considered new as it is the first time to our knowledge to use a fascial block as a main component of anaesthesia for PCNL and the investigators think that it may be used as a solo anaesthesia. This will lead to decreasing patient stay in the hospital, decreasing time for patient ambulation and regaining vitality and hemostasis that will all be in line with early rehabilitation after surgery (ERAS) protocol that is the aim of all health care services in modern medicine. Also, it will be the base for further research in more risky patient groups that may decrease the detrimental effect of general anaesthesia in these patient group which already have associated comorbidities and for more operation especially if unilateral.

In this study, the investigators will evaluate the efficacy and safety of ultrasound-guided QLB as an anaesthetic method in patients undergoing PCNL.

Adult patients who will undergo elective unilateral PCNL will be included. Low dose spinal anaesthesia will be done at L3-4 lumbar vertebrae. Then, ultrasound-guided QLB (QL 1,2,3) will be performed on the ipsilateral surgical side, using a low-frequency convex transducer. The total volume of injectate will not exceed 0.4 ml /kg of (bupivacaine 0.5%).

The success of the procedure, procedure-related complications, Intra- and post-operative hemodynamics, pain score, overall surgeon and patient satisfaction will be evaluated.

Eligibility Criteria:
Inclusion Criteria:

* Adult patients who will undergo an elective unilateral PCNL and agree to participate in the study will be included

Exclusion Criteria:

* Uncooperable patients
* Pregnant women
* Untreated urinary tract infection
* Uncorrected coagulation disorder
* Known allergy to study medications
* Local infection at the site of injection.