Anästhesie und klinische Forschung
Offener Zugang

Abstrakt

The Efficacy of Preemptive Ketamine Administration in Bilateral Superficial Cervical Plexus Block After Thyroid Surgery

Ayman Abd Al-maksoud Yousef and Walid Ahmed Mostafa

Background: Peripheral tissue injury initiates peripheral sensitization; in addition, it triggers excitability of the central neurons known as central sensitization. N-methyl–D-aspartate (NMDA) receptors are largely involved in the pathogenesis of central sensitization. The concept of preemptive local anesthetic administration seems hopeful in management of postoperative pain. The addition of ketamine as NMDA receptors antagonist reduces the incidence of chronic pain and the chance for development of hyperalgesia and allodynia. Our study hypothesis is to evaluate effects of adding ketamine to bupivacaine in bilateral superficial cervical plexus block (BSCPB) on acute and chronic pain after thyroid surgery. Patients and

Methods: Sixty (ASA I, II) 18 to 60 years old undergoing thyroid surgery were simply randomized into two equal groups, thirty patients received BSCPB using 9 ml bupivacaine 0.25% solution mixed with 1 ml normal saline (Bupivacaine group) and thirty patients received BSCPB using 9 ml bupivacaine 0.25% solution mixed with 1 ml ketamine 50 mg/ml (Ketamine group). Patients were instructed about the use of a 10 cm Visual Analog Scale (VAS) (0=no pain to 10=worst possible pain). Pain level was recorded at PACU admission every 3 h for the first 24 hours. The analgesic requirement during the first 24 h after surgery was recorded. Any side effects were recorded. The incidences of chronic pain, wound hyperalgesia and allodynia after six months were recorded.

Results: Intraoperative fentanyl requirements were significantly reduced in ketamine group. At post-anesthesia care unit, acetaminophen requirements during the first 24 hours after surgery were significantly reduced in ketamine group. The incidence of wound hyperalgesia and allodynia were significantly lower in ketamine group.

Conclusion: Pre-incisional BSCPB using bupivacaine 0.25% in addition to 50 mg ketamine demonstrated significant reduction in intraoperative and postoperative analgesic requirement after thyroid surgery. The incidences of chronic pain, wound hyperalgesia and allodynia were significantly reduced after six months in ketamine group.