Nerve Block, Orthopedic Surgery, Shoulder
Conditions
Keywords
Analgesia, Patient-controlled, Anesthesia, Regional, Ultrasound, Postoperative Pain, Brachial Plexus
Brief summary
This study has been designed to assess the possible advantages of using ultrasound imaging to block the brachial plexus (i.e., nerves of the upper limb) in patients undergoing shoulder surgery. The ultrasound technique will be compared with the current gold standard, electrical nerve stimulation. The aim of this study is to define which technique is better in terms of time to onset of anesthesia.
Detailed description
The study will compare real-time ultrasound (US) guidance and electrical nerve stimulation (ENS) in terms of onset time for interscalene brachial plexus anesthesia. The main hypothesis is that direct visualization of neural structures under US guidance will grant better local anesthetic (LA) disposition around the roots of the plexus, thus improving onset times. Perineural catheters will be used to maintain regional analgesia for 48 hours after surgery. We hypothesize that US guidance may also help physicians place perineural catheters more precisely, thus improving analgesia in the following hours to days. Finally, we will investigate for possible differences in minor adverse events such as vascular puncture, pain during the anesthetic procedure.
Interventions
PROCEDUREUltrasound-guided continuous interscalene brachial plexus block
With patients in the supine position, a high-frequency (10-12 MHz) ultrasound transducer in a sterile sheath will be applied to explore the interscalene region and locate the brachial plexus. The transducer will be positioned so as to image the C5 and C6 roots in a single view. Visualization of the C7 root in the same scan will be sought, but will not be required. A 50-mm, 20 G needle will be advanced in-plane from the postero-lateral side of the transducer. Injection of the local anesthetic will be performed in small aliquots while repositioning of the needle in order to optimize spread of the injectate around the nerve roots. At the end of the injection, a catheter will be threaded through the needle. The catheter will be positioned to lie deep and close to the imaged nerve roots.
DRUGFentanyl
50 µg iv prn (in the intraoperative period)
PROCEDUREContinuous interscalene brachial plexus block using electrical nerve stimulation
With patients in the supine position, the head will be rotated to the contralateral side. The interscalene groove will be palpated. A 35-mm, 20 G needle will be inserted at the estimated C6 level (cricoid cartilage) with a 30-45° angle to the skin. The needle will be advanced along a line joining the insertion site to the axilla. An electrical nerve stimulator will be used at an initial intensity of 1.0 mA (frequency: 2 Hz, pulse width: 0.2 ms). A musculocutaneous or axillary-nerve mediated twitch will be sought Injection of the local anesthetic will start with a visible motor response at a current \<0.5 mA. The catheter will be positioned to as to elicit a motor response at ≤0.4 mA.
DRUGRopivacaine
Block induction \[1% (wt/vol) solution\]: 20 ml (200 mg) Postoperative analgesia \[0.2% (wt/vol) solution\]: * Background infusion: 4 ml/h (8 mg/h) * Incremental on-demand dose: 2 ml (4 mg) * Lockout time: 15 min
DRUGParacetamol
1 g iv q8h
DRUGMorphine
5 mg im prn q1h (in the postoperative period)
PROCEDUREGeneral anesthesia
Will be given in case of block failure and/or patient discomfort intractable with fentanyl during the procedure. The technique will be left at the discretion of the attending anesthesiologist. Monitored anesthesia care will also be acceptable; the block will be considered as failed in that case as well.
Sponsors
University of Parma
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 85 Years
Healthy volunteers
No
Inclusion criteria
* ASA Physical Status Class I-III * Elective surgery of the shoulder * Informed consent to regional anesthesia
Exclusion criteria
* Inability to effectively communicate * Chronic opioid use * Absence of informed consent to participation to the study * Ipsilateral upper limb neurological deficits * Known allergy to study medications * Contraindications to continuous block placement
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Onset time of brachial plexus anesthesia | ≤30 min |
Secondary
| Measure | Time frame |
|---|---|
| Additional analgesic requirements during surgery | Duration of surgery |
| Incidence of paresthesiae during the anesthetic procedure | ≤30 min |
| Incidence of blood aspiration during the anesthetic procedure | ≤30 min |
| Successful brachial plexus anesthesia | ≤30 min |
| Pain during performance of the block | ≤30 min |
| Pain at rest and on movement (visual analog scale) | q8h until 48 h after surgery |
| Local anesthetic consumption on patient-controlled pump | ≤48 h |
| Number of needle redirections for the performance of the block | ≤30 min |
Countries
Italy
Outcome results
None listed