Adverse Reaction to Peripheral Nerve- and Plexus-blocking Anesthetics Clinical Trial
Official title:
A Double Blind Randomised Control Trial Assessing Effects of Local Anaesthetic Concentration (0.5% vs 0.75%) and Volume (5mls vs 15mls) on the Respiratory Consequences of Ultrasound Guided Interscalene Brachial Plexus Nerve Block
Shoulder surgery is known to be extremely painful requiring high doses of opiate analgesics
(morphine) to control pain. Morphine has numerous unwanted side effects including sedation,
hallucinations and vomiting.
It is now standard procedure for patients undergoing shoulder surgery to have their pain
controlled by means of an injection made around the nerves where they pass through the neck
to supply the shoulder with sensation (similar to the numbing injections made by the dentist
before a dental procedure). This injection is called a 'nerve block'.
Nerve blocks provide complete analgesia after shoulder surgery allowing clinicians to
discharge patients home on the day of surgery, pain free and with no opiate side effects.
However, a side effect of nerve blocks at this level is involvement of the phrenic nerve,
which is anatomically close to the injection point. This may cause (temporary) paralysis of
the diaphragm and in some cases, severe respiratory dysfunction.
Research shows that reducing either the volume or the concentration of the drug injected,
can reduce the consequent respiratory dysfunction. However no study has compared both volume
and concentration in parallel, to see which of these has the more significant effect in
reducing respiratory dysfunction. Furthermore there has been no assessment of how these
changes may affect the duration of analgesia received and patient coping after discharge.
The investigators propose to conduct a double blind randomised controlled trial at the Royal
Surrey County Hospital, enrolling patients presenting for elective day case arthroscopic
(key hole) surgery over a period of 6 months. Patients will receive one of four treatment
allocations:
1. Low concentration-high volume of local anaesthetic
2. Low concentration-low volume of local anaesthetic
3. High concentration-high volume of local anaesthetic
4. High concentration-low volume of anaesthetic drug of local anaesthetic.
The aim of this study is to inform an optimum dosing regimen for patients in order to
facilitate maximal pain relief and quality of recovery with minimum respiratory dysfunction.
n/a
Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Outcomes Assessor), Primary Purpose: Supportive Care