Ketamine as Adjunctive Analgesic With Bupivacaine in Paravertebral Analgesia for Breast Cancer Surgery
Condition: Acute Pain; Chronic Pain
MeSH terms: Chronic Pain; Acute Pain
Study type: Interventional
Phase: Phase 1/Phase 2

Summary: 
      This study aims to investigate the safety and the analgesic efficacy of adding Ketamine to
      bupivacaine 0.25% in thoracic PVB in patients undergoing modified radical mastectomy.
    

Detailed description: 
      Breast cancer is perhaps the most common cancer in women that requires frequent surgical
      intervention. Nearly 40% of post-operative breast surgery patients experience significant
      acute post-operative pain, with a pain score above five reflecting inadequacy of conventional
      pain management. Most of the responses of the human body to post-surgical pain have been
      proven to be detrimental to the patient's homeostasis and recovery. Moreover, the incidence
      of chronic postoperative pain in breast surgery patients is as high as 50% and inadequate
      analgesia is considered as an independent risk factor. Hence, a number of therapeutic
      measures have been accepted as a part of the "multi-modal" approach to post-operative pain
      control. Thoracic Paravertebral Block (PVB) is used for pain relief after thoracotomy , and
      mastectomy. PVB can provide profound, long lasting sensory differentiation. The resulting
      greater attenuation of surgical stress response may translate into reduced inotropic
      stimulation of the heart. Additionally, unlike general anesthesia, PVB can provide superior
      postoperative analgesia, less nausea and vomiting, shorter recovery time; require fewer
      analgesic, earlier mobilization, and earlier home readiness for discharge. The use of PVB in
      patients undergoing ambulatory breast surgery has cost-saving potential. There is little
      systematic research on the efficacy and tolerability of the addition of adjunctive analgesic
      agent in paravertebral analgesia. The addition of adjunctive analgesics, such as fentanyl and
      clonidine to local anesthetics has been shown to enhance the quality and duration of sensory
      neural blockade, and decrease the dose of local anesthetic and supplemental analgesia .

      Ketamine is an anaesthetic agent with potent analgesic properties. Its mode of action
      includes noncompetitive antagonism at N-methyl d-aspartate (NMDA) receptors and a local
      anaesthetic effect. ketamine has been extensively used through epidural and caudal routes
      with variable results.It possesses some definite advantages over the conventional local
      anaesthetic agents as it stimulates cardiovascular system and respiratory system.The
      advantages of ketamine include a good analgesic effect, cardio vascular stability in a
      hypotensive state, bronchodilatation in asthmatics, and the absence of awareness.
      Disadvantages include increased heart rate and blood pressure, emergence phenomenon,
      laryngospasm and apnea, increases in intracranial and intraocular pressure, and the lack of
      visceral anesthesia.
    

Intervention name(s): paravertebral block
Intervention type(s): Drug
Intervention description(s): Thoracic paravertebral blocks will be performed as described by Moore and Katz. Intradermal lidocaine will be used at the site of the needle insertion. The superior aspect of the spinous processes of T1- T6 will be marked. The skin entry points will 3 cm laterals to the marks. A 22- gauge quincke spinal needle attach to extension tubing to a syringe containing study drugs will be used. The needle will be inserted perpendicular to the skin for a distance of 2 to 4 cm until the transverse process will contact. The needle will be withdrawn and walk cephalad off the transverse process and advance for a further 1.5 to 2 cm.
Other intervention name(s): ketamine hydrochloride
Intervention MeSH terms: Ketamine
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: ketamine; adjuvant; paravertebral block