A Phase 4 interventional study of Dexmedetomidine & Bupivacaine and Ketamine Hydrochloride and Bupivacaine in Postoperative Pain and Total Abdominal Hysterectomy, sponsored by Bangladesh Medical University. Not yet recruiting at 1 site in Bangladesh. Open to female participants aged 25 Years to 60 Years. Per ClinicalTrials.gov, last updated 2026-09-29.
Sponsored by Bangladesh Medical University · Phase 4, Interventional, and Treatment
Total abdominal hysterectomy is associated with significant postoperative pain due to abdominal wall incision and tissue manipulation. Effective pain management after surgery helps improve patient comfort, early mobilization, and recovery while reducing the need for opioid medications and their related side effects.
The transversus abdominis plane (TAP) block is a regional anaesthesia technique that provides pain relief by blocking sensory nerves supplying the abdominal wall. However, the duration of analgesia provided by local anaesthetic alone may be limited. Adding adjuvant drugs such as dexmedetomidine or ketamine may enhance and prolong the analgesic effect.
This randomized controlled trial aims to compare the effectiveness of dexmedetomidine and ketamine as adjuvants to bupivacaine in ultrasound-guided bilateral TAP block for postoperative pain management following total abdominal hysterectomy.
Participants undergoing elective total abdominal hysterectomy will be randomly assigned to receive either bupivacaine with dexmedetomidine or bupivacaine with ketamine during TAP block. Postoperative pain intensity, morphine consumption, time to first rescue analgesia, haemodynamic changes, sedation level and postoperative nausea and vomiting will be assessed during the first 24 hours after surgery.
The findings of this study may help determine which adjuvant provides better postoperative analgesia when combined with bupivacaine for TAP block in patients undergoing total abdominal hysterectomy.
Postoperative pain following total abdominal hysterectomy is influenced by both somatic and visceral components. The abdominal wall incision contributes significantly to somatic pain, while pelvic tissue manipulation contributes to visceral pain. Effective perioperative analgesia is essential to facilitate recovery and reduce opioid-related adverse effects.
The transversus abdominis plane (TAP) block is an established regional anaesthesia technique that provides analgesia by depositing local anaesthetic within the fascial plane between the internal oblique and transversus abdominis muscles, thereby reducing transmission of nociceptive signals from the abdominal wall. However, the duration of analgesia achieved with local anaesthetic alone may be limited, leading to interest in the use of adjuvant medications to enhance and prolong analgesic effects.
Dexmedetomidine and ketamine have different pharmacological mechanisms that may contribute to improved analgesia when combined with local anaesthetics. Dexmedetomidine, an α2-adrenergic receptor agonist, may enhance peripheral nerve block effects through modulation of neuronal excitability and nociceptive transmission. Ketamine, through NMDA receptor antagonism, may reduce central sensitization and hyperalgesia. Although both agents have demonstrated analgesic benefits in regional anaesthesia, comparative evidence regarding their relative effectiveness as adjuvants in TAP block for patients undergoing total abdominal hysterectomy remains limited.
This study is designed to generate comparative evidence regarding the analgesic efficacy and safety profile of these two commonly used adjuvant agents when administered with bupivacaine in ultrasound-guided TAP block. The findings may contribute to optimizing multimodal analgesic strategies and improving postoperative recovery after major gynaecological surgery
Exclusion Criteria:
Participants allocated to this group will receive an ultrasound-guided bilateral Transversus Abdominis Plane (TAP) block using 0.25% bupivacaine combined with dexmedetomidine as an adjuvant. A total volume of 30 mL of bupivacaine solution (15 mL per side) will be administered, with a total dose of 0.5 µg/kg dexmedetomidine, divided equally between both sides. The TAP block will be performed after induction of general anaesthesia and tracheal intubation, before the start of surgery.
Drug: Dexmedetomidine & Bupivacaine
Participants allocated to this group will receive an ultrasound-guided bilateral Transversus Abdominis Plane (TAP) block with 0.25% bupivacaine and ketamine hydrochloride as an adjuvant. A total volume of 30 mL of bupivacaine solution (15 mL per side) will be administered, with a total ketamine hydrochloride dose of 1 mg/kg, divided equally between both sides. The TAP block will be performed after induction of general anaesthesia and tracheal intubation, before the start of surgery.
Drug: Ketamine Hydrochloride and Bupivacaine
Ultrasound-guided bilateral Transversus Abdominis Plane (TAP) block will be performed after induction of general anesthesia and tracheal intubation, before the start of surgery. The block will be administered at the mid-axillary line by identifying the external oblique, internal oblique, and transversus abdominis muscle layers using a high-frequency linear ultrasound probe. The study intervention consists of administering 0.25% bupivacaine combined with dexmedetomidine 0.5 microgram/kg as an adjuvant.
Ketamine hydrochloride 1 mg/kg administered as an adjuvant with 0.25% bupivacaine during ultrasound-guided bilateral TAP block.
Total postoperative morphine consumption in miligram (mg)
Total morphine sulfate consumption during the first 24 postoperative hours.
Time frame: 24 hours after surgery
Postoperative Pain Intensity
Postoperative pain intensity will be assessed using the 11-point Numeric Rating Scale (NRS), where 0 indicates no pain, and 10 indicates the worst imaginable pain. Pain scores will be recorded at rest and during movement at predefined postoperative time points. The NRS pain scores will be compared between the dexmedetomidine and ketamine groups following total abdominal hysterectomy.
Time frame: 2, 4, 6, 12, and 24 hours after surgery
Time to First Rescue Analgesic Request
The time interval from completion of surgery to the first requirement of rescue analgesia (intravenous morphine sulfate) will be recorded and compared between the dexmedetomidine and ketamine groups. Rescue analgesia will be administered when the Numeric Rating Scale (NRS) pain score reaches ≥4.
Time frame: First 24 hours after surgery
Heart Rate (HR)
Heart rate will be recorded before administration of the ultrasound-guided TAP block (baseline) and subsequently monitored after surgery. The changes in heart rate will be compared between the dexmedetomidine and ketamine groups to assess haemodynamic response following the intervention.
Time frame: Baseline [before Tranversus Abdominis Plane (TAP) Block], and 2, 4, 6, 12, and 24 hours after surgery
Systolic Blood Pressure (SBP)
Systolic blood pressure will be measured before administration of the ultrasound-guided TAP block (baseline) and during the postoperative period. Changes in systolic blood pressure will be compared between the dexmedetomidine and ketamine groups.
Time frame: Baseline [before Tranversus Abdominis Plane (TAP) Block], and 2, 4, 6, 12, and 24 hours after surgery
Diastolic Blood Pressure (DBP)
Diastolic blood pressure will be measured before administration of the ultrasound-guided TAP block (baseline) and during postoperative follow-up. Changes in diastolic blood pressure will be compared between the dexmedetomidine and ketamine groups.
Time frame: Baseline [before Tranversus Abdominis Plane (TAP) Block], and 2, 4, 6, 12, and 24 hours after surgery
Mean Arterial Pressure (MAP)
Mean arterial pressure will be recorded before administration of the ultrasound-guided TAP block (baseline) and during postoperative follow-up. Changes in mean arterial pressure will be compared between the dexmedetomidine and ketamine groups to assess haemodynamic stability.
Time frame: Baseline [before Tranversus Abdominis Plane (TAP) Block], and 2, 4, 6, 12, and 24 hours after surgery
Postoperative Nausea and Vomiting (PONV)
The occurrence of postoperative nausea and vomiting will be assessed and compared between the dexmedetomidine and ketamine groups. Data regarding postoperative nausea and vomiting episodes will be collected from the postoperative record sheet after completion of the 24-hour postoperative observation period.
Time frame: Within 24 hours after surgery
Sedation Level (Ramsay Sedation Score)
Postoperative sedation level will be assessed using the Ramsay Sedation Score and compared between the dexmedetomidine and ketamine groups. The Ramsay Sedation Score is a 6-point ordinal scale ranging from 1 to 6, where 1 indicates an anxious, agitated, or restless patient and 6 indicates no response to stimulation. Higher scores indicate a greater level of sedation. The score will be recorded during the postoperative observation period.
Time frame: 2, 4, 6, 12, and 24 hours after surgery
Plan to share: No
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Bangladesh Medical University