Comparing Dexamethasone With Dexmedetomidine as Additives to Bupivacaine in Adductor Canal Block for Knee Arthroscopy.

Comparing Dexamethasone With Dexmedetomidine as Additives to Bupivacaine in Adductor Canal Block for Knee Arthroscopy.

Comparative Study Between Dexamethasone, and Dexmedetomidine as Additives to Bupivacaine in Ultrasound Guided Adductor Canal Block in Knee Arthroscopy

a comparison shall be conducted between dexamethasone accompanied by bupivacaine, on one hand, and dexmedetomedine accompanied by bupivacaine, on the other hand for pain-free knee arthroscopic surgeries.

Arthroscopic knee surgery can cause significant postoperative pain to the degree that can potentially delay timely discharge from the ambulatory surgical setting. Analgesia after knee surgery can be provided by multiple, non-systemic, non-opioid-based methods, including local anesthetic infiltration, peripheral nerve blockade, neuraxial procedures, and intra-articular injections. The femoral nerve block has been shown to be superior to traditional intra-articular injection of local anesthetics in some knee surgeries, but motor blockade of the quadriceps muscle, with the potential risk for falls, limits the value of femoral blocks for less invasive ambulatory surgery. Orthopedic surgery is increasingly being performed on an ambulatory basis, where perioperative analgesia can improve timely discharge in the outpatient setting. A trans-arterial landmark-based distal approach to the saphenous nerve block has been shown to reduce pain significantly by providing sensory block to the tissues around the medial meniscus. The saphenous nerve, a terminal branch of the femoral nerve, provides cutaneous sensation to the peripatellar region, and the medial aspect of the lower extremity below the knee, as well as to the articular branches to the medial aspect of the knee joint. The saphenous nerve separates from the femoral nerve in the proximal third of the thigh, courses through the adductor canal with the nerve to the vastus medialis, and emerges from the adductor hiatus to divide into the infrapatellar branch and the sartorial branch. Traditionally, saphenous nerve blocks have been performed as an anatomical landmark-based technique with marginal rates of success, as low as 33%. With ultrasound guidance, the feasibility of effective saphenous nerve block at the adductor canal has been shown tp increase. The adductor canal block may provide superior analgesia over traditional distal saphenous nerve blocks for surgical procedures of the knee because this block includes the saphenous nerve, the nerve to the vastus medialis, and potentially the articular contribution of the obturator nerve to the knee joint. Our primary hypothesis was that performing an adductor canal block as part of a multimodal analgesic regimen would result in improved analgesia immediately following arthroscopic medial meniscectomy. Dexamethasone improves the quality and duration of peripheral nerve block when used as an adjuvant to local anesthetic. Possible mechanisms include: Dexamethasone (as a corticosteroid) was reported to attenuate C-fiber responses. More recent publications indicate that 8 mg dexamethasone added to perineural local anesthetic injections augment the duration of peripheral nerve block analgesia. Dexmedetomidine is a useful sedative agent with analgesic properties, hemodynamic stability and ability to recover respiratory function in mechanically ventilated patients facilitating early weaning. Besides being a new modality of sedation and analgesia in ICU patient management, it has been studied in several other perioperative settings. researchers suggested that dexmedetomidine likely affects the Aδ and unmyelinated C fibers differently from motor neurons. This phenomenon has been observed before in the setting of neuraxial blockade; however, the exact mechanism of action remains speculative and has been addressed elsewhere. Rationale for using Adjuvants in Regional anesthesia:- Regional anesthesia researchers have been exploring the strategies to prolong the duration of PNB "Peripheral Nerve Blockade" analgesia in patients undergoing ambulatory procedures. Although ambulatory catheters are an effective option, their practical utility is governed by a stringent patient selection criteria. Liposomal bupivacaine is another effective alternative, but its use is limited by price, availability, lack of FDA approval, and the similar prolongation of both sensory and motor blockade duration it produces. Adjuvants constitute another option, and numerous local anesthesia additives, have been explored in search of the ideal adjunct that satisfies the criteria of effectively prolonging the duration of analgesia and not being associated with a significant risk of neurotoxicity. Among these adjuncts, dexamethasone has seemed most promising, because researchers have demonstrated its efficacy when administered intravenously. However, dexmedetomidine as a local anesthetic adjunct may ultimately prove superior to dexamethasone in terms of its differential prolongation of sensory-motor blockade.

All patients will receive spinal anesthesia with 2.5 ml 0.5% hyperbaric bupivacaine at the L3/4 interspaces in the setting position. Ultrasound blocks will be done immediately after spinal anesthesia, before surgical intervention. In this arm, patients will receive 20 ml mixture of 0.25% bupivacaine and 4 mg dexamethasone.

All patients will receive spinal anesthesia with 2.5 ml 0.5% hyperbaric bupivacaine at the L3/4 interspaces in the setting position. Ultrasound blocks will be done immediately after spinal anesthesia, before surgical intervention. In this arm, patients will receive 20 ml mixture of 0.25% bupivacaine and 0.5 Mg/kg dexmedetomidine.

spinal anesthesia shall be conducted with 2.5 ml 0.5% hyperbaric bupivacaine at the L3/4 interspaces in the setting position.

Ultrasound blocks will be done immediately after spinal anesthesia, before surgical intervention. A high-frequency linear ultrasound transducer was placed transverse to the longitudinal axis of the extremity at the midthigh level at a distance approximately halfway between the iliac spine and the patella. The femoral artery was identified underneath the sartorius muscle with the vein just underneath the artery. At this position, the saphenous nerve was placed lateral to the artery in the adductor canal (Fig. 1). A 10 cm Tuohy canula 18G "Gauge" (Braun Medical, Melsungen, Germany) was inserted, in plane, from the lateral side of the transducer, through the sartorius muscle with the tip placed lateral to the artery. then, a 20-ml mixture of 0.25% bupivacaine, and 4 mg dexamethasone will be injected.

Ultrasound blocks will be done immediately after spinal anesthesia, before surgical intervention. A high-frequency linear ultrasound transducer was placed transverse to the longitudinal axis of the extremity at the midthigh level at a distance approximately halfway between the iliac spine and the patella. The femoral artery was identified underneath the sartorius muscle with the vein just underneath the artery. At this position, the saphenous nerve was placed lateral to the artery in the adductor canal (Fig. 1). A 10 cm Tuohy canula 18G "Gauge" (Braun Medical, Melsungen, Germany) was inserted, in plane, from the lateral side of the transducer, through the sartorius muscle with the tip placed lateral to the artery.then, a 20-ml mixture of 0.25% bupivacaine, and 0.5 Mg/kg dexmedetomidine will be injected.

Inclusion Criteria: - Adult patients of aged < 18 years old ASA "American Society of Anaesthesia" physical status I or II under-going any unilateral knee arthroscopy. Exclusion Criteria: - patient refusal. Pregnancy or breastfeeding Known contraindications to peripheral nerve block, including local skin infections, bleeding diathesis, and coagulopathy. Allergies to local anesthetics, dexmedetomidine, or any component of multimodal analgesia.

Iskandar H, Benard A, Ruel-Raymond J, Cochard G, Manaud B. Femoral block provides superior analgesia compared with intra-articular ropivacaine after anterior cruciate ligament reconstruction. Reg Anesth Pain Med. 2003 Jan-Feb;28(1):29-32. doi: 10.1053/rapm.2003.50019.

Ilfeld BM, Duke KB, Donohue MC. The association between lower extremity continuous peripheral nerve blocks and patient falls after knee and hip arthroplasty. Anesth Analg. 2010 Dec;111(6):1552-4. doi: 10.1213/ANE.0b013e3181fb9507. Epub 2010 Oct 1.

Fortier J, Chung F, Su J. Unanticipated admission after ambulatory surgery--a prospective study. Can J Anaesth. 1998 Jul;45(7):612-9. doi: 10.1007/BF03012088.

Akkaya T, Ersan O, Ozkan D, Sahiner Y, Akin M, Gumus H, Ates Y. Saphenous nerve block is an effective regional technique for post-menisectomy pain. Knee Surg Sports Traumatol Arthrosc. 2008 Sep;16(9):855-8. doi: 10.1007/s00167-008-0572-4. Epub 2008 Jun 24.

Kapoor R, Adhikary SD, Siefring C, McQuillan PM. The saphenous nerve and its relationship to the nerve to the vastus medialis in and around the adductor canal: an anatomical study. Acta Anaesthesiol Scand. 2012 Mar;56(3):365-7. doi: 10.1111/j.1399-6576.2011.02645.x.

Horn JL, Pitsch T, Salinas F, Benninger B. Anatomic basis to the ultrasound-guided approach for saphenous nerve blockade. Reg Anesth Pain Med. 2009 Sep-Oct;34(5):486-9. doi: 10.1097/AAP.0b013e3181ae11af.

Benzon HT, Sharma S, Calimaran A. Comparison of the different approaches to saphenous nerve block. Anesthesiology. 2005 Mar;102(3):633-8. doi: 10.1097/00000542-200503000-00023.

Manickam B, Perlas A, Duggan E, Brull R, Chan VW, Ramlogan R. Feasibility and efficacy of ultrasound-guided block of the saphenous nerve in the adductor canal. Reg Anesth Pain Med. 2009 Nov-Dec;34(6):578-80. doi: 10.1097/aap.0b013e3181bfbf84.

Ishiguro S, Yokochi A, Yoshioka K, Asano N, Deguchi A, Iwasaki Y, Sudo A, Maruyama K. Technical communication: anatomy and clinical implications of ultrasound-guided selective femoral nerve block. Anesth Analg. 2012 Dec;115(6):1467-70. doi: 10.1213/ANE.0b013e31826af956. Epub 2012 Aug 10.

Lund J, Jenstrup MT, Jaeger P, Sorensen AM, Dahl JB. Continuous adductor-canal-blockade for adjuvant post-operative analgesia after major knee surgery: preliminary results. Acta Anaesthesiol Scand. 2011 Jan;55(1):14-9. doi: 10.1111/j.1399-6576.2010.02333.x. Epub 2010 Oct 29.

Horner G, Dellon AL. Innervation of the human knee joint and implications for surgery. Clin Orthop Relat Res. 1994 Apr;(301):221-6.

Jenstrup MT, Jaeger P, Lund J, Fomsgaard JS, Bache S, Mathiesen O, Larsen TK, Dahl JB. Effects of adductor-canal-blockade on pain and ambulation after total knee arthroplasty: a randomized study. Acta Anaesthesiol Scand. 2012 Mar;56(3):357-64. doi: 10.1111/j.1399-6576.2011.02621.x. Epub 2012 Jan 4.

An K, Elkassabany NM, Liu J. Dexamethasone as adjuvant to bupivacaine prolongs the duration of thermal antinociception and prevents bupivacaine-induced rebound hyperalgesia via regional mechanism in a mouse sciatic nerve block model. PLoS One. 2015 Apr 9;10(4):e0123459. doi: 10.1371/journal.pone.0123459. eCollection 2015.

Abdallah FW, Dwyer T, Chan VW, Niazi AU, Ogilvie-Harris DJ, Oldfield S, Patel R, Oh J, Brull R. IV and Perineural Dexmedetomidine Similarly Prolong the Duration of Analgesia after Interscalene Brachial Plexus Block: A Randomized, Three-arm, Triple-masked, Placebo-controlled Trial. Anesthesiology. 2016 Mar;124(3):683-95. doi: 10.1097/ALN.0000000000000983.

Kaur M, Singh PM. Current role of dexmedetomidine in clinical anesthesia and intensive care. Anesth Essays Res. 2011 Jul-Dec;5(2):128-33. doi: 10.4103/0259-1162.94750.