Onset and Duration of Forearm Nerve Blockade

• Lidocaine (Drug): lidocaine 1%, distal ( ulnar and medial nerve): 6ml/nerve , 12m total
• Bupivacaine (Drug): Bupivacaine 0.5%,distal ( ulnar and medial nerve): 6ml/nerve , 12m total
• Lidocaine (Drug): lidocaine 1%, distal and proximal ( ulnar and medial nerve): 3ml/nerve , 12m total

Primary outcomes

• onset of successful block and duration of sensory-motor blockade of the median and ulnar nerves [5-minute beginning at the end of the last injection]: Block success is defined as full sensory block of the areas and muscles supplied by the median and ulnar nerves. Block failure is defined as absence of sensory blockade at 30 min in the median and ulnar nerve territories as assessed by pin-prick, cold and light touch.
• onset of successful block and duration of sensory-motor blockade of the median and ulnar nerves [10-minute beginning at the end of the last injection]: Block success is defined as full sensory block of the areas and muscles supplied by the median and ulnar nerves. Block failure is defined as absence of sensory blockade at 30 min in the median and ulnar nerve territories as assessed by pin-prick, cold and light touch.
• onset of successful block and duration of sensory-motor blockade of the median and ulnar nerves [15-minute beginning at the end of the last injection]: Block success is defined as full sensory block of the areas and muscles supplied by the median and ulnar nerves. Block failure is defined as absence of sensory blockade at 30 min in the median and ulnar nerve territories as assessed by pin-prick, cold and light touch.
• onset of successful block and duration of sensory-motor blockade of the median and ulnar nerves [20-minute beginning at the end of the last injection]: Block success is defined as full sensory block of the areas and muscles supplied by the median and ulnar nerves. Block failure is defined as absence of sensory blockade at 30 min in the median and ulnar nerve territories as assessed by pin-prick, cold and light touch.
• onset of successful block and duration of sensory-motor blockade of the median and ulnar nerves [25-minute beginning at the end of the last injection]: Block success is defined as full sensory block of the areas and muscles supplied by the median and ulnar nerves. Block failure is defined as absence of sensory blockade at 30 min in the median and ulnar nerve territories as assessed by pin-prick, cold and light touch.
• onset of successful block and duration of sensory-motor blockade of the median and ulnar nerves [30-minute beginning at the end of the last injection]: Block success is defined as full sensory block of the areas and muscles supplied by the median and ulnar nerves. Block failure is defined as absence of sensory blockade at 30 min in the median and ulnar nerve territories as assessed by pin-prick, cold and light touch.
• onset of successful block and duration of sensory-motor blockade of the median and ulnar nerves [45-minute beginning at the end of the last injection]: Block success is defined as full sensory block of the areas and muscles supplied by the median and ulnar nerves. Block failure is defined as absence of sensory blockade at 30 min in the median and ulnar nerve territories as assessed by pin-prick, cold and light touch.
• onset of successful block and duration of sensory-motor blockade of the median and ulnar nerves [60-minute beginning at the end of the last injection]: Block success is defined as full sensory block of the areas and muscles supplied by the median and ulnar nerves. Block failure is defined as absence of sensory blockade at 30 min in the median and ulnar nerve territories as assessed by pin-prick, cold and light touch.
• onset of successful block and duration of sensory-motor blockade of the median and ulnar nerves [Post Anesthesia Care Unit arrival]: Block success is defined as full sensory block of the areas and muscles supplied by the median and ulnar nerves. Block failure is defined as absence of sensory blockade at 30 min in the median and ulnar nerve territories as assessed by pin-prick, cold and light touch.
• onset of successful block and duration of sensory-motor blockade of the median and ulnar nerves [15-minute after Post Anesthesia Care Unit arrival]: Block success is defined as full sensory block of the areas and muscles supplied by the median and ulnar nerves. Block failure is defined as absence of sensory blockade at 30 min in the median and ulnar nerve territories as assessed by pin-prick, cold and light touch.
• onset of successful block and duration of sensory-motor blockade of the median and ulnar nerves [30-minute after Post Anesthesia Care Unit arrival]: Block success is defined as full sensory block of the areas and muscles supplied by the median and ulnar nerves. Block failure is defined as absence of sensory blockade at 30 min in the median and ulnar nerve territories as assessed by pin-prick, cold and light touch.
• onset of successful block and duration of sensory-motor blockade of the median and ulnar nerves [Post Anesthesia Care Unit discharge]: Block success is defined as full sensory block of the areas and muscles supplied by the median and ulnar nerves. Block failure is defined as absence of sensory blockade at 30 min in the median and ulnar nerve territories as assessed by pin-prick, cold and light touch.

Secondary outcomes

• postoperative Numeric Rating Scale (NRS) [screening Day0 (prior to the nerve block), post block, PACU arrival, Day0 evening, Day1 morning and evening, Day2 morning and evening, Day3 morning and evening, Day4, Day5, Day6, Day7]: pain rating(numeric rating scale) at rest and with movement ( scale 0:no pain - 10:worst pain)
• postoperative Numeric Rating Scale (NRS) [post block]: pain rating( Numeric Rating Scale) at rest and with movement ( scale 0:no pain - 10:worst pain)
• postoperative Numeric Rating Scale (NRS) [Post Anesthesia Care Unit arrival]: pain rating( Numeric Rating Scale) at rest and with movement ( scale 0:no pain - 10:worst pain)
• postoperative Numeric Rating Scale (NRS) [Day 0 evening]: pain rating( Numeric Rating Scale) at rest and with movement ( scale 0:no pain - 10:worst pain)
• postoperative Numeric Rating Scale (NRS) [Day 1 morning]: pain rating( Numeric Rating Scale) at rest and with movement ( scale 0:no pain - 10:worst pain)
• postoperative Numeric Rating Scale (NRS) [Day 1 evening]: pain rating( Numeric Rating Scale) at rest and with movement ( scale 0:no pain - 10:worst pain)
• postoperative Numeric Rating Scale (NRS) [Day 2 morning]: pain rating( Numeric Rating Scale) at rest and with movement ( scale 0:no pain - 10:worst pain)
• postoperative Numeric Rating Scale (NRS) [Day 2 evening]: pain rating( Numeric Rating Scale) at rest and with movement ( scale 0:no pain - 10:worst pain)
• postoperative Numeric Rating Scale (NRS) [Day 3 morning]: pain rating( Numeric Rating Scale) at rest and with movement ( scale 0:no pain - 10:worst pain)
• postoperative Numeric Rating Scale (NRS) [Day 3 evening]: pain rating( Numeric Rating Scale) at rest and with movement ( scale 0:no pain - 10:worst pain)
• postoperative Numeric Rating Scale (NRS) [Day 4]: pain rating( Numeric Rating Scale) at rest and with movement ( scale 0:no pain - 10:worst pain)
• postoperative Numeric Rating Scale (NRS) [Day 5]: pain rating( Numeric Rating Scale) at rest and with movement ( scale 0:no pain - 10:worst pain)
• postoperative Numeric Rating Scale (NRS) [Day 6]: pain rating( Numeric Rating Scale) at rest and with movement ( scale 0:no pain - 10:worst pain)
• postoperative Numeric Rating Scale (NRS) [Day 7]: pain rating( Numeric Rating Scale) at rest and with movement ( scale 0:no pain - 10:worst pain)
• postoperative Numeric Rating Scale (NRS) [Day 30]: pain rating( Numeric Rating Scale) at rest and with movement ( scale 0:no pain - 10:worst pain)

Sex: All, ages: 18 Years to 80 Years, accepts healthy volunteers

Inclusion Criteria:

* Scheduled to undergo daycare surgery for carpal tunnel syndrome under peripheral nerve blocks
* American Society of Anesthesiologists (ASA) physical status I, II or III
* Able to demonstrate sensory function in the ulnar and median nerve distribution by exhibiting sensitivity to cold, pinprick and light touch
* Scheduled to undergo primary hand surgery
* Able to understand the Dutch language, purpose and risks of the study
* Able to provide informed consent and authorization to use protected health information, adhere to the study visit schedule, and complete all study assessments

Exclusion Criteria:

* Currently pregnant or nursing
* History of hypersensitivity to local anesthetics
* Contraindication to lidocaine, bupivacaine, paracetamol
* Medical condition that will make it difficult to assess sensory distributions of the upper extremity peripheral nerves or to communicate with staff
* Suspected or known recent history (< 3 months) of drug or alcohol abuse
* Concurrent physical condition that may require analgesic treatment (such as NSAID or opioid) in the postsurgical period for pain that is not strictly related to Carpal Tunnel Syndrome and which may confound the postsurgical assessments
* Infection at the planned block site(s)
* Initiation of treatment with any of the following medications within 1 month of study drug administration or if the medication(s) are being given to control pain: selective serotonin reuptake inhibitors (SSRIs), selective norepinephrine reuptake inhibitors (SNRIs), gabapentin, pregabalin (Lyrica®), or duloxetine (Cymbalta®)
* Body weight <40 kg or body mass index >44 kg/m2
* Uncontrolled anxiety, psychiatric, or neurological disorder that might interfere with study assessments
* Any chronic neuromuscular deficit affecting the Ulnar and Median nerves or muscles of the surgical extremity
* Any chronic condition or disease that would compromise neurological
* Presence of pre-existing coagulation disorders
* Baseline neurological deficits