In this study, the investigators will compare two different anesthetic solutions in the infraclavicular block in patients having forearm, wrist, and hand surgery. The solutions will be bupivacaine 0.5% versus bupivacaine 0.25% plus lidocaine 1%, both associated with epinephrine 5 mcg/ml and dexamethasone 4 mg. The main objective of this investigation is to demonstrate that using higher concentrations of bupivacaine alone results in a significant block duration increase compared with the mixture of bupivacaine and lidocaine.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
SUPPORTIVE_CARE
Masking
QUADRUPLE
Enrollment
40
Infraclavicular block with 35 ml of the following anesthetic solution: Bupivacaine 0.25% + Lidocaine 1% + dexamethasone 4 mg + epinephrine 5 mcg/ml
Infraclavicular block with 35 ml of the following anesthetic solution: Bupivacaine 0.5% + dexamethasone 4 mg + epinephrine 5 mcg/ml
Hospital de San Carlos Dr. Benicio Arzola Medina
San Carlos, Región de Ñuble, Chile
Motor block duration
The time interval in minutes between the end of the local anesthetic injection and the return of hand mobility.
Time frame: 0 - 48 hours after block
Sensory block duration
The time interval in minutes between the end of the local anesthetic injection and the return of hand sensation.
Time frame: 0 - 48 hours after block
Analgesic block duration
The time interval in minutes between the end of the local anesthetic injection and the first sensation of pain in the surgical area.
Time frame: 0 - 48 hours after block
Sensory and motor block score
The sensorimotor block will be assessed every 5 minutes until 60 minutes after the end of local anesthetic injection using a 16-point composite score evaluating sensory and motor block of musculocutaneous, median, radial, and ulnar nerves. Sensation will be assessed with a pinprick test in each nerve territory with a 0 to 2-point scale. 0= no block, patients can feel a pin prick; 1= analgesic block, the patient can feel touch but not pinprick; 2= anesthetic block, the patient cannot feel pinprick 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.
Time frame: 0 - 60 minutes after block
Block onset time
The time interval in minutes between the end of the local anesthetic injection and a minimal sensorimotor composite score of 14 out of 16 points. The sensorimotor score is described in Outcome 4.
Time frame: 0 - 60 minutes after block
Incidence of successful block
Patients with a minimal sensorimotor score of 14 out of 16 points, with at least 7 points in the sensitive score. The sensorimotor score is described in Outcome 4.
Time frame: 0 - 60 minutes after block
Incidence of failed block
Patients with a sensorimotor score of 13 points or less. The sensorimotor score is described in Outcome 4.
Time frame: 0 - 60 minutes after block
Incidence of anesthetic block
Ability to proceed with the surgery without general anesthesia, rescue blocks, or local anesthesia infiltration by the surgeon.
Time frame: 60 to 120 minutes after the ending time of local anesthetic injection
Procedural pain
Pain related to the nerve block according to 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-point score means the worst imaginable pain.
Time frame: Immediately after nerve block
Image time
The time interval in seconds between the probe placement and the acquisition of the final ultrasonographic image.
Time frame: 2 hours before surgery
Needle time
The time interval in seconds between the skin infiltration and the end of local anesthetic injection
Time frame: 2 hours before surgery
Block performance time
Sum of image and needle time
Time frame: 2 hours before surgery
Number of patients requiring general anesthesia
Patients who need general anesthesia to proceed with the surgery
Time frame: 60 to 120 minutes after the ending time of local anesthetic injection
Diaphragmatic function
Diaphragmatic excursion in millimeters evaluated by ultrasound in three different times: pre-block, 60 minutes after block, and at the end of the surgery
Time frame: From arrival to the pre-anesthesia unit to the end of surgery
Rate of diaphragmatic paresis
Patients with decreased diaphragmatic excursion by 25% to 75% compared with the basal function 60 minutes after the block or at the end of the surgery.
Time frame: From 60 minutes after block to the end of the surgery
Rate of diaphragmatic paralysis
Patients with decreased diaphragmatic excursion greater than 75% compared with the basal function, absence of diaphragmatic movement, or paradoxical movement 60 minutes after the block or at the end of the surgery.
Time frame: From 60 minutes after block to the end of the surgery
Incidence of rebound pain
Severe pain (NRS ≥ 7) in the surgical area within 24 hours after the block wears off.
Time frame: 24 hours after the block wears off
Incidence of nerve block side effects
The presence of Horner syndrome, paresthesia, vascular puncture, hematoma, or local anesthetic systemic toxicity after the nerve block.
Time frame: From skin anesthesia to 60 minutes after the nerve block
Postoperative complications
Presence of persistent paresthesia, numbness, or motor deficit in the postoperative period.
Time frame: 7 days after surgery
Duration of surgery
Time in minutes between skin incision and closure.
Time frame: 3 hours after skin incision
Pain score in the post-anesthesia care unit (PACU)
Highest pain reported by the patient in the PACU according to 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-point score means the worst imaginable pain.
Time frame: 3 hours after the end of the surgery
Length of PACU stay
The time interval in minutes between PACU arrival to readiness to discharge
Time frame: 3 hours after the end of the surgery
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