Comparative study of different concentrations of prilocaine and ropivacaine for intraoperative axillary brachial plexus block

Risk factors for insufficient ultrasound-guided supraclavicular brachial plexus block

PURPOSE

Ultrasound-guided supraclavicular brachial plexus block (SCBPB) is performed by surgeons for upper limb anesthesia; however, certain patients need additional local anesthesia. This study aimed to identify risk factors for additional local anesthetic injection requirements.

METHODS

In total, 269 patients receiving ultrasound-guided SCBPB were enrolled. Patient age, sex, body mass index, anesthetic drug dose, surgeon expertise (hand surgeon or resident), tourniquet time, comorbidities (diabetes mellitus and mental disorders), and preoperative blood pressure representing anxiety were compared between the additional local anesthesia and no additional local anesthesia groups matched for background using propensity scores. Receiver operating characteristic analysis was performed to determine risk factor cut-off values with the highest predictive potential.

RESULTS

Of 269 patients, 41 (15.2%) required additional intraoperative local anesthesia. Among surgical sites, elbow surgery showed the highest prevalence of the need for additional local anesthesia (17/41, 41%). A high body mass index and high systolic blood pressure before surgery were identified as risk factors for additional intraoperative local anesthesia requirement. Furthermore, systolic blood pressure > 170 mmHg (area under the curve, 0.66) predicted the need for intraoperative local anesthesia with 36% sensitivity, 89% specificity, 37.5% positive predictive value, and 88.6% negative predictive value. The median systolic blood pressure was significantly greater in patients requiring additional local anesthesia than in those not requiring it [151 (139-171) mmHg vs. 145 (127-155) mmHg; P = 0.026].

CONCLUSION

Elbow surgery, obesity, and high systolic blood pressure (> 170 mmHg) before surgery are predictive of additional intraoperative local anesthesia requirement.

LEVEL OF EVIDENCE

Prognostic Level III.

A randomised, non-inferiority study of chloroprocaine 2% and ropivacaine 0.75% in ultrasound-guided axillary block

Chloroprocaine is a short-acting local anaesthetic with a rapid onset of action and an anaesthesia duration up to 60 min. In this pivotal study success rates, onset and remission of motor and sensory block and safety of chloroprocaine 2% was compared to ropivacaine 0.75% for short-duration distal upper limb surgery with successful block rates as primary outcome. The study was designed as a prospective, randomised, multi-centre, active-controlled, double-blind, parallel-group, non-inferiority study, performed in 4 European hospitals with 211 patients scheduled for short duration distal upper limb surgery under axillary plexus block anaesthesia. Patients received either ultrasound guided axillary block with 20 ml chloroprocaine 2%, or with 20 ml ropivacaine 0.75%. Successful block was defined as block without any supplementation in the first 45 min calculated from the time of readiness for surgery. 90.8% patients achieved a successful block with chloroprocaine 2% and 92.9% patients with Ropivacaine 0.75%, thus non-inferiority was demonstrated (10% non inferiority margin; 95% CI − 0.097, 0.039; p = 0.02). Time to onset of block was not significantly different between the groups. Median time to motor and sensory block regression was significantly shorter as was time to home discharge (164 [155–170] min for chloroprocaine versus 380 [209–450] for the ropivacaine group, p < 0.001). For short-duration surgical procedures, the short-acting Chloroprocaine 2% may be used, with success rates non-inferior to ropivacaine and a favourable safety profile.

Trial registration: The trial was registered at Clinicaltrials.gov with registration number NCT02385097 (March 11th, 2015) and European Clinical Trial Database with the EudraCT number 2014-002519-40 (July 7th, 2015, Austria—BASG).

Prolonged Analgesic Efficacy of Articaine with the Addition of Tramadol in Axillary Brachial Plexus Block

Objectives

Articaine is a rapid-onset, short-duration, local anesthetic. The aim of this study was to study the effect of adding tramadol to articaine in an axillary block to prolong the analgesic effect.

Methods

This study was conducted with 60 patients of American Association of Anesthesiologists classification I or II and aged 18 to 60 years who underwent hand or forearm surgery with an axillary plexus block using a nerve stimulation technique. The patients were randomized into 2 groups: Group A (n=30) received 40 mL 1% articaine and Group AT (n=30) was administered 40 mL 1% articaine with 100 mg tramadol. The onset of sensory block, motor block, duration of sensorial block and motor block, duration of analgesia and hemodynamic parameters were recorded before the block and 5, 10, 20, 30, 60, 120, 180 minutes after the local anesthetic injection.

Results

The sensory block duration in Group AT (187.5±13.0 min) was significantly longer than that of group A (140.78±8.74 min) (p<0.02). The motor block duration in Group AT (137.4±3 min) was significantly longer than that seen in Group A (93.71±9.6 min) (p<0.01). The duration of analgesia was longer in Group AT (218.8±18.2 min) than in Group A (170.8±17.2 min) (p<0.05). In group AT, 2 patients experienced the side effect of nausea and 1 patient had hypotension in the postoperative period.

Conclusion

This study demonstrated that the addition of 100 mg of tramadol to articaine used for an axillary plexus block prolonged analgesia.

Tramadol does not prolong the effect of ropivacaine 7.5 mg/ml for axillary brachial plexus block

BACKGROUND

The aim of this prospective, randomized, double-blind study was to evaluate the effect of the addition of tramadol to ropivacaine on the onset and duration of sensory and motor block, and duration of analgesia, for axillary brachial plexus block.

METHODS

After institutional approval and informed consent had been obtained, 45 patients scheduled for forearm or hand surgery under axillary brachial plexus block were randomly allocated into two groups. The ropivacaine group received 40 ml of ropivacaine 7.5 mg/ml plus 2 ml of isotonic sodium chloride solution, and the tramadol group received 40 ml of ropivacaine 7.5 mg/ml plus 2 ml (100 mg) of tramadol. The onset and duration of sensory and motor block in the distribution of the musculocutaneous, radial, median and ulnar nerves, the duration of analgesia, the time to first pain medication, hemodynamics and side-effects were recorded.

RESULTS

The addition of tramadol did not improve the speed of onset or increase the duration of sensory and motor block. The durations of analgesia were 631 +/- 33 min and 633 +/- 37 min (mean +/- standard deviation) in the ropivacaine and tramadol groups, respectively (P > 0.05). Hemodynamic parameters and side-effects did not differ between the groups.

CONCLUSION

The addition of 100 mg of tramadol to 7.5 mg/ml of ropivacaine, for axillary brachial plexus block, does not prolong the duration of motor and sensory block and analgesia.