Potential advantages of an additional forearm rubber tourniquet in intravenous regional anesthesia: a randomized clinical trial

Although the usefulness of an additional forearm tourniquet to conventional intravenous regional anesthesia (IVRA) has been reported, the forearm cuff may disturb the surgical field to some degree, especially in wrist surgery. In the present study, we assessed the clinical efficacy of a temporary additional forearm rubber tourniquet to the conventional upper arm tourniquet on the quality of IVRA. The study included 32 ASA physical status I and II adult patients undergoing elective hand surgery who were randomly allocated to either an additional forearm tourniquet group (Group F) or to a conventional upper arm tourniquet group (Group C). Upper arm tourniquet IVRA was established using 40 mL of 0.5 % lidocaine in Group C. Hypothetically enhanced forearm tourniquet IVRA was established using 10 mL of 0.5 % lidocaine with an additional forearm rubber tourniquet and then administering 30 mL of 0.25 % lidocaine after removing the forearm tourniquet in Group F. The sensory and motor block onset and recovery times, onset time of tourniquet pain, intraoperative fentanyl consumption, and incidence of local anesthetic toxicity were recorded. The numerical rating score (NRS) of perioperative and postoperative pain and quality of anesthesia were also assessed. Although the total dose of lidocaine in Group F was less and the sensory and motor block onset times were significantly shorter in Group F than those in Group C (P < 0.05), there was no difference regarding sensory and motor block recovery times, onset time of tourniquet pain, intraoperative fentanyl consumption, NRS of perioperative and postoperative pain, and the quality of anesthesia in the two groups (P > 0.05). Compared with Group C, the incidence of local anesthetic toxicity (i.e., dizziness, 43.8 vs 6.2 %, P = 0.02) was significantly decreased in Group F. The combination of the additional forearm and upper arm tourniquets with a smaller amount of local anesthetic achieved more rapid onset of sensory and motor block, a similar quality of anesthesia and a lower incidence of local anesthetic toxicity compared with the conventional technique.