Intravenous Versus Perineural Effect Dexamethasone in Interscalene Nerve Block With Levobupivacaine

Intravenous Versus Perineural Dexamethasone in Interscalene Nerve Block With Levobupivacaine for Shoulder and Upper Arm Surgeries

Interscalene brachial plexus block can be used as an additive to general anaesthesia or as the primary anaesthetic for shoulder surgeries for pain management. The investigators compared the effect of perineural versus intravenous dexamethasone on the prolongation of the action of levobupivacaine in ultrasound guided interscalene block for shoulder and upper arm surgeries.

Dexamethasone had been shown to prolong the duration of postoperative analgesia when given as an adjuvant for peripheral nerve blocks. The investigators compared the effect of perineural versus intravenous dexamethasone on the prolongation of the action of levobupivacaine in ultrasound guided interscalene block for shoulder and upper arm surgeries. The study hypothesized that adding perineural dexamethasone to levobupivacaine in ultrasound guided interscalene block may be more superior to adding intravenous dexamethasone to levobupivacaine and levobupivacaine alone in shoulder and upper arm surgeries as regard analgesic effect, duration of analgesia and hemodynamic stability.

Patients will receive levobupivacaine plus saline in interscalene brachial plexus block in addition to intravenous saline.

Patients will receive levobupivacaine-dexamethasone in interscalene brachial plexus block plus intravenous saline.

Patients will receive levobupivacaine plus saline in interscalene brachial plexus block in addition to intravenous dexamethasone.

Patients will receive 20 ml of 0.25% levobupivacaine plus 2ml saline in interscalene brachial plexus block plus 10 ml intravenous saline.

Patients will receive 20 ml of 0.25% levobupivacaine plus 4mg dexamethasone diluted in 2 ml saline in interscalene brachial plexus block plus 10 ml intravenous saline.

Patients will receive 20 ml of 0.25% levobupivacaine plus 2ml saline in interscalene brachial plexus block plus 4 mg intravenous dexamethasone diluted in 10 ml saline.

Patients will be closely observed until 30 minutes after the end of local anesthetic injection. Block success will be defined as loss of sensation to pinprick in the C4 and C5 sensory dermatome distribution measured 30 minutes after the end of local anesthetic injection. sensory block will be assessed by pin prick test using a 3point scale: • Grade 0 = Normal sensation. Grade 1 = loss of sensation to pin prick (analgesia). Grade 2 = loss of sensation to touch (anaesthesia). Onset time for sensory block will be defined as the time interval between the end of local anaesthesia administration and complete sensory block (score 2).

defined as the time interval between complete sensory block (score 2) and complete resolution of anaesthesia on all nerves (score 0)

Motor block will be determined according to the modified Bromage scale: Grade 0 = Normal motor function with full flexion and extention of elbow. Grade 1 = Decrease motor power. Grade 2 = Complete motor block. Onset time of motor block will be defined as the time interval between end of local anaesthetic administration and complete motor block (grade 2).

defined as the time interval between complete motor block (score 2) and complete recovery of motor function of the arm (score 0).

the intraoperative analgesic dose consumption would be calculated The investigators can use fentanyl as analgesic if the patient required during the surgery ( 50-100 mic)

The VAS is represented with straight line with one end has the anchor " no pain" and it takes 0, while the other end of the line has the anchor " pain as bad as it could be" and it takes 10. The patient will receive the rescue analgesic when the score is more than 4)

Total analgesic need to rescue analgesic (pethidine) calculated by mg. And the onset of time for first intravenous analgesia during the 24 hours postoperative by hours.

concerning the procedure is assessed using a 2-point scale (1= satisfied, I would want the same anesthesia / analgesia method for the next surgery, 2= unsatisfied, I would want a different anesthesia / analgesia method for the next surgery).

Inclusion Criteria: American Society of Anesthesiologists physical status grade I and grade II. Exclusion Criteria: Patient refusal. Neuromuscular diseases (as myopathies, myasthenia gravies, …...) Hematological diseases, bleeding or coagulation abnormality. Psychiatric diseases. Local skin infection Sepsis at site of the block. Known intolerance to the study drugs. Body Mass Index > 40 Kg/m2 contralateral phrenic palsy pneumothorax pneumectomy severe COPD