Introduction: Adding opioids to local anesthetic solutions leads to enhanced anesthesia and
provide postoperative analgesia. Intrathecaly injected opioids have some side effects,
though. One of them is pruritus. Objective: We designed a randomized, double‐blinded,
placebo‐controlled study to evaluate prophylactic impact of continuous IV Magnesium 10mg/kg
over 30 minutes on intrathecal fentanyl‐induced pruritus start at the end of the operation.

Methods: ASA I‐II Patient’s candidate for orthopedic operations under spinal anesthesia
(10‐15mg hyperbaric bupivacaine and 25 µg fentanyl intrathecal) and will be divided randomly
into two groups:

Control group (Placebo group): bolus 100 ml nacl 0.9% at end of surgery Study group (Mg ++
group): (continuous IV Magnesium 10mg/kg in 100 ml Nacl0.9% over 30 minutes at end of
surgery).

Study outcome:

1. Hemodynamics: Systolic blood pressure, Mean arterial blood pressure, pulse rate, O2
saturation will be recorded in 5 min,10 min,30 min,60 min and every one hour till 6
hours after the operation.

2. Pruritus Patients were asked about existence (present=1,no=0), severity (mild=1,
modret=2, sever =3) and site of pruritus (Face(trigeminal) =1, neuroaxial(dermatome)=2),
1,2,4, and 6 hours after operation. Incidence of pruritus total group incidence %.

3. The incidence of PONV.