Comparison of analgesic effect of morphine added as adjuvant to bupivacaine and pure bupivacaine in usg guided adductor canal block performed after total knee arthroplasty

Adductor canal block is an effective method for postoperative analgesia, especially in patients who undergo total knee arthroplasty (TDA). Adjuvant drugs are added to local anesthetic drugs to increase both the quality and the duration of analgesic effect. These drugs are opioids, clonidine, tramadol, neostigmine, ketamine, adenosine, dexmedetomidine and somatostatin. In this study, we aimed to evaluate efficacy of morphine, added as adjuvant to local anesthesia in adductor canal block, on analgesia grade and consumption, nausea and vomiting and patient satisfaction. After written consent of ethics committee and patients are taken, 60 patients aged 40-80 in ASA I-III status who undergo TDA under spinal anesthesia in AIBU Izzet Baysal Training and Research Hospital operating room were included. Patients were divided randomly double blinded into 2 groups, Group M (bupivacaine + morphine) and Group B (morphine), with randomized prospective closed envelope method. Spinal anesthesia from L3-4 or L4-5 level in sitting position with 15 mg hyperbaric bupivacaine (Bustein 0,5% Spinal heavy-Bupivacaine HCl 20 mg/4 ml-VEM) is performed to patients in both group. After operation is completed and sensory block regress to T12 level, adductor canal block with 0,5% Bupivacaine (Bustesin %0,5 Vem, Turkey) 10 mL,, Morphine HCl (Morphıne Hcl 0,01 g/mL, Galen,Istanbul) 1mL and 9 mL 0,9% NaCl is applied to patients in group M. Adductor canal block with 10 mL 0,5% Bupivacaine and 9 mL 0,9% NaCl is applied to patients in group B. With intravenosus (IV) PCA (Patient Controlled Analgesia) is applied to all patients, Tramadol HCl 5 mg/ml consantration with 400 mg/24h maximum dose allowed and continuous opioid infusion, doses adjusted to 10 mg tramadol HCl with a lock-in interval of 20 minutes. Patients were monitored for VAS (Visual Analog Scale) vi value, patient satisfaction level, analgesic consumption and possible side effects for 24 hours. There was no statistically significant difference between groups in terms of demographic features and anesthesia data (p>0.05). VAS resting and movement median values at 8th hour were statistically significantly lower in Group M than Group B (p value=0.002). The consumption of tramadol in Group M was found to be statistically significantly lower in the 12-24 hours range and total consumption levels (p-value=0.022), (p-value=0.049). There was no statistically significant difference between the groups in terms of patient satisfaction (p-value=0.978). As a result, we came to conclusion that the morphine added to bupivacaine in adductor canal block lowers the VAS score, decreases the analgesic consumption, increases frequency of nausea and cause no significant difference in patient satisfaction. Key words: Total knee arthroplasty, postoperative pain, adductor canal block, bupivacaine, morphine.