Dexmedetomidine in IVRA

After obtaining approval of the medical and ethical committee of Menoufia University & Nasser Institute for Research and Treatment, an informed and written consent from the patients, a prospective controlled randomized double blinded study will be performed

Sample size:

MedCalc® version 12.3.0.0 program "Ostend, Belgium" was used for calculations of sample size, statistical calculator based on 95% confidence interval and power of the study 80% with α error 5%, According to a previous study (13), showed that the duration of tourniquet time in group A was mean 51.60±5.157 and Group B was mean 53.80±4.773, with p-value >0.05, while Quality of block of excellent in group A 83.3% and group B 90%, it turns out that there is success in the group B compared to group A, but there is no difference. So it can be relied upon in this study, based on this assumption, sample size was calculated according to these values produced a minimal samples size of 86 cases were enough to find such a difference. Assuming a drop-out ratio of 5%, the sample size will be 90 cases, subdivided into three groups 30 cases in each group. Patients will be randomly categorized into three equal groups (30 patients each): The patients will be randomly allocated to one of these three groups, using a computer-generated sequence of random numbers and a sealed envelope technique.

Inclusion criteria

• Patients of ASA class I and II.
• Patients of either sex.
• Patients aged between 20-70 years.
• Patients scheduled for forearm and hand surgery lasting for about 60 minutes.

Exclusion criteria

• Patient with known hypersensitivity to any study medications.
• Patient with Severe peripheral vascular disease and neurological disease.
• Where use of tourniquet will be either not possible or contraindicated.
• Patient with Hemolytic diathesis specially sickle cell anemia, epilepsy, diabetes mellitus, hypertension, cardiovascular disease like myocardial infarction, cardiac arrhythmias, heart block and altered mentation.
• Procedures lasting for more than 90 min will be also not considered.
• Therapy with adrenergic receptor antagonist, calcium channel blocker and ACE inhibitors.
• Patient with impaired liver function.