Intravenous Dexmedetomidine Combined with Ultrasound-Guided Rectus Sheath Block for Open Gastrectomy: a Prospective...

To compare the incidences of positive hemodynamic response (HR > 100 beats min^-1 or SBP > 160 mmHg) during abdominal exploration and moderate pain after surgery, when using dexmedetomidine infusion and rectus sheath block.

One hundred patients undergoing open gastrectomy were randomized to receive rectus sheath block with ropivacaine (Group B, n = 25), initial loading dose of 0.6 μg kg^-1 dexmedetomidine, followed by a continuous infusion of 0.2 μg kg^-1 h^-1 throughout surgery (Group D, n = 25), both rectus sheath block and dexmedetomidine (Group BD, n = 25), or neither rectus sheath block nor dexmedetomidine (Group C, n = 25). General anesthesia techniques were standardized. HR, SBP, and positive hemodynamic response at peritoneum incision (T_PI), 5 min (T_AE-5), 10 min (T_AE-10), and 15 min (T_AE-15) after the start of abdominal exploration, and incidences of moderate postoperative pain were recorded.

Positive hemodynamic responses during abdominal exploration were more common in Groups B (82%) and C (74%) than in Groups D (14%) and BD (9%) (all P = 0.000). HR and SBP were lower in Groups D and BD, compared with those in Groups C and B (all P < 0.05). Compared with T_PI, HR and SBP increased significantly in Groups B and C during abdominal exploration (all P < 0.05)_, but not in Group BD (except HR at T_AE-15). The incidences of moderate pain in Groups B and BD were noticeably lower than in Groups C and D at 1 h, 2 h, and 6 h after surgery (all P < 0.0083).

Dexmedetomidine infusion combined with rectus sheath block provided more hemodynamic stability during abdominal exploration and better analgesia after surgery.