Plasma Concentration of Lidocaine and Bupivacaine Axillary BPB Mixture Solutions [PCLBAxMix]
Plasma Concentration of Lidocaine and Bupivacaine Axillary BPB Mixture Solutions [PCLBAxMix]
The doses of local anesthetics can be decreased with the use of ultrasound guidance. In case
 of using mixture solutions the benefits and drawbacks are controversial. The plasma
 concentrations were not studied up to this time in this kind of settings, so investigators
 believe that this is the first work that shows how lidocaine change the plasma concentration
 of bupivacaine after axillary approach to brachial plexus employed with different dilute and
 mixed solutions for upper limb surgery in trauma patients.
Total of 30 American Society of Anesthesiologist (ASA) I-III adult patients scheduled to
 elective or emergency trauma surgery of hand and forearm under ultrasound-guided (UG)
 brachial plexus block (BPB) are planned to be assigned into this randomized-prospective
 observational study after approval by the University Research Ethics Board, Pécs University
 Medical School, Hungary. All of the patients will receive detailed information about the
 planned BPB techniques and surgeries, then written informed consents will be obtained.

 Study participants are planned to be assigned randomly by the research coordinator into 3
 groups (Lidocaine, Bupivacaine and mixture solution) according to the concentration of
 lidocaine and bupivacaine in the mixture solution.

 Standardized UG Axillary-supraclavicular (AX-SC) approach to the BP is planned to be
 performed under sterile conditions by the same anesthesiologist. The standardized dose is 0.4
 ml/kg with the targeted maximized the single-shot volume of 30 ml.

 Blood samples will be taken at 0-time point (straight after the administration of BP
 injection) and 30, 60, 240 and 480 minutes after. Plasma concentrations are determined, the
 results are collected and analyzed.

 Under standard monitorization, vital parameters, data are collected on the onset time and
 duration of actions of local anesthetics (LAs).
Inclusion Criteria:

 -  unpremedicated patient scheduled for elective or emergency trauma surgery of hand and
 forearm under ultrasound-guided BPB

 Exclusion Criteria:

 -  continuous peripheral nerve catheter technique or bilateral block was planned, or the
 patient refused to participate. Exclusion criteria included psycho-mental conditions
 interfering with consent or assessment; pre-existing chronic pain condition or daily
 analgesic or sedative consumption; sedative or analgesic premedication; pre-existing
 neurological disorders aﬀecting the brachial plexus.