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Pharmacokinetic Analysis of Bupivacaine in the Presence and Absence of Perineural Dexamethasone in Axillary Blockade

Phase 4
Completed
Conditions
Acute Pain
Upper Extremity Injury
Analgesia
Interventions
Registration Number
NCT05359731
Lead Sponsor
University of Chile
Brief Summary

The investigators will conduct a prospective, randomized, double-blinded study using an axillary brachial plexus block in patients undergoing elective surgery of the distal forearm and hand to characterize and describe the pharmacokinetics of bupivacaine associated with perineural dexamethasone.

The pharmacokinetic analysis will be performed by measuring bupivacaine plasma levels at different time intervals after the blockade (15, 30, 45, 60, and 90 minutes), allowing comparison between 2 different groups: Bupivacaine (B) and Bupivacaine-dexamethasone (BD).

Thus, the hypothesis is that plasma levels of bupivacaine during the first 90 minutes after a blockade are lower in the presence of perineural dexamethasone, suggesting a decrease, at least initially, in systemic absorption from the injection site.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
20
Inclusion Criteria
  • American Society of Anesthesiologists classification 1-2
  • Real weight between 80 and 100 kg
  • Body mass index between 20 and 30
Exclusion Criteria
  • Adults who are not capable of giving their own consent
  • Medical history or physical findings of pre-existing neuropathy
  • Coagulopathy (assessed by history and physical examination and, if deemed clinically necessary, by blood work up i.e. platelets ≤ 100, International Normalized Ratio ≥ 1.4 or prothrombin time ≥ 50)
  • Renal failure (assessed by history and physical examination and, if deemed clinically necessary, by blood work up i.e. creatinine ≥ 100)
  • Hepatic failure (assessed by history and physical examination and, if deemed clinically necessary, by blood work up i.e. transaminases ≥ 100)
  • Allergy to local anesthetics (LAs)
  • Pregnancy
  • Previous surgery in the axillary region of the surgical side

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Perineural Bupivacaine plus DexamethasoneBupivacaine Hydrochloride with DexamethasoneBupivacaine with Dexamethasone in axillary brachial plexus blockade
Perineural BupivacaineBupivacaine HydrochlorideBupivacaine without Dexamethasone in axillary brachial plexus blockade
Primary Outcome Measures
NameTimeMethod
Maximum plasma concentration (Cmax) of bupivacaine0 to 90 minutes after the ending time of local anesthetic injection

Maximum plasmatic level of bupivacaine

Secondary Outcome Measures
NameTimeMethod
Time to obtain the maximum plasma concentration of bupivacaine (Tmax)0 to 90 minutes after the ending time of local anesthetic injection

Time in minutes in which the maximum plasmatic level of bupivacaine is reached

Sensory and motor block score30 minutes after the ending time of local anesthetic injection

The sensorimotor block will be assessed every 5 minutes until 30 minutes after the end of local anesthetic injection using a 16-point composite score evaluating sensory and motor block of musculocutaneous, medium, radial, and ulnar nerves.

Sensation will be assessed with ice in each nerve territory with a 0 to 2 point scale. 0= no block, patients can feel cold; 1= analgesic block, the patient can feel touch but not cold; 2= anesthetic block, the patient cannot feel cold or touch.

The motor function will be assessed for each nerve with a 0 to 2 points scale where 0= no motor block; 1= paresis; 2= paralysis.

Successful blocks at 30 minutes correlate with a final score ( sum of all individual sensory and motor scores) of at least 14 points out of 16.

Analgesic block duration48 hours after the ending time of local anesthetic injection

The elapsed period in minutes between the ending time of the local anesthetic injection and the time of the first sensation of pain in the surgical area

Plasmatic concentration of bupivacaine at 15 minutes15 minutes after the ending time of local anesthetic injection

Plasmatic level of bupivacaine 15 minutes after local anesthetic injection (ng/ml)

Plasmatic concentration of bupivacaine at 30 minutes30 minutes after the ending time of local anesthetic injection

Plasmatic level of bupivacaine 30 minutes after local anesthetic injection (ng/ml)

Persistent neurologic deficit7 days after surgery

Presence of persistent sensory or motor postoperative deficit.

Area under the curve of plasma concentration versus time at 90 minutes (AUC90)0 to 90 minutes after the ending time of local anesthetic injection

Area under the curve at 90 minutes

Intensity of pain during block procedureDuring the execution of the nerve blockade

Evaluated with the Numeric Rating Scale for Pain. This scale is graduated from 0 to 10 points. A 0-point score represents the absence of pain, and a 10-points score represents the worst imaginable pain. Patients will be asked to rate their pain verbally with this scale. The blinded assessor will register the score reported.

Block performance timeFrom the skin anesthesia to the end of local anesthetic injection

Sum of: 1- the acquisition time of the ultrasonographic image. and 2- the time to perform the block itself (from the skin anesthesia to the end of local anesthetic injection)

Plasmatic concentration of bupivacaine at 45 minutes45 minutes after the ending time of local anesthetic injection

Plasmatic level of bupivacaine 45 minutes after local anesthetic injection (ng/ml)

Plasmatic concentration of bupivacaine at 60 minutes60 minutes after the ending time of local anesthetic injection

Plasmatic level of bupivacaine 60 minutes after local anesthetic injection (ng/ml)

Plasmatic concentration of bupivacaine at 90 minutes90 minutes after the ending time of local anesthetic injection

Plasmatic level of bupivacaine 90 minutes after local anesthetic injection (ng/ml)

Block onset time30 minutes after the ending time of local anesthetic injection

Time required to reach a minimal sensorimotor composite score of 14 points out of a maximum of 16 points. The sensorimotor score is described in outcome 9.

Incidence of successful block30 minutes after the ending time of local anesthetic injection

Percentage of blocks with a minimal sensorimotor composite score of 14 points out of a maximum of 16 points at 30 minutes after the injection

Motor block duration48 hours after the ending time of local anesthetic injection

The elapsed period in minutes between the ending time of the local anesthetic injection and the time of return of hand and fingers movement.

Sensory block duration48 hours after the ending time of local anesthetic injection

The elapsed period in minutes between the ending time of the local anesthetic injection and the time of the return of hand and fingers sensation

Incidence of nerve block side effectsFrom the skin anesthesia to the end of local anesthetic injection

Determined by the presence of paresthesia, local anesthetic systemic toxicity, vascular puncture after the block.

Trial Locations

Locations (1)

Hospital Clínico Universidad de Chile

🇨🇱

Santiago, Metropolitan, Chile

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