Clinical trial NCT02589054: Regional Changes in Upper Limb Perfusion Following Brachial Plexus Block: A Pilot Study
Official title: Regional Changes in Upper Limb Perfusion Following Brachial Plexus Block: A Pilot Study
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Anesthesia, Conduction
Nerve Block
Sympathectomy
Regional Blood Flow
Lead sponsor: London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's
Sponsor class: OTHER
Collaborators: name: University of Western Ontario, Canada
name: London Health Sciences Centre
name: St. Joseph's Health Care London
First posted: 2015-10-28
Enrollment: 18
Sex: ALL
Minimum age (years): 18
Maximum age (years): 80
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Individuals coming for elective upper extremity surgery who would already be having a brachial plexus block for their anesthesia.

Brief summary: Ultrasound-guided regional anesthesia is increasingly being used in the modern surgical environment to provide specific intraoperative anesthesia and postoperative analgesia. Infiltration of local anesthesics around peripheral nerves firs blocks sympathetic, then sensory, then motor nerve function. Sympathectomy-induced vasodilation following brachial plexus block results in increased skin temperature and arterial flow within minutes.

Although it has not been shown to reliably increase diameter or cross-sectional area of distal arteries, brachial plexus block does change the pattern and quantity of blood flow to the hand. Given that the magnitude of change of flow cannot be attributed to vessel radius, the investigators suspect that the more laminar fluid dynamics are due to vascular tone.

The investigators study aims to quantify alterations in physiology and peripheral vasodilator response. The investigators anticipate that axially block will significantly improve regional blood flow.


Eligibility criteria: Inclusion Criteria:

* ASA physical status I, II, III
* BMI less than or equal to 39
* Presenting for elective upper limb surgery
* Does not meet any exclusion criteria

Exclusion Criteria:

* Age over 80
* ASA physical status IV or V
* BMI greater or equal to 40
* Language barrier precluding ability to give informed consent
* History of coagulopathy
* INR \< 1.4
* Platelet count \< 100
* Allergy to local anesthetics
* Known peripheral vascular disease of the upper limbs
* Amputation of one or both upper limbs, not including digits
* Peripheral neurological disease
* Does not consent to participate in study

Primary outcomes:
measure: Changes in regional blood flow and perfusion characteristics in the upper arm arteries from baseline to 20 minutes after unilateral axillary block.
timeFrame: 30 minutes
Secondary outcomes:
measure: Changes in the caliber of the arteries of the arm between arms from baseline to 20 minutes after unilateral axillary block.
timeFrame: 30 minutes
measure: Changes in skin temperature between hands from baseline to 20 minutes after unilateral axillary block.
timeFrame: 30 minutes
measure: Sensory loss in radial, ulnar, and median nerve distribution between hands from baseline to 20 minutes after unilateral axillary block.
timeFrame: 30 minutes
measure: Motor weakness in radial, ulnar, and median nerve distributions between hands from baseline to 20 minutes after unilateral axillary block
timeFrame: 30 Minutes
Other outcomes:
Locations:
Study officials:
References: