How does a sleeping medicine influence the blood particles during knee surgery
- Conditions
- Medical and Surgical, Undergoing knee replacement surgery ,
- Registration Number
- CTRI/2017/08/009548
- Lead Sponsor
- Department of Anaesthesia and Intensive care
- Brief Summary
Role of tourniquetapplication in lower limb surgery has dual benefits. It not only provides abloodless filed to the surgeon but is an essential component of patient bloodmanagement strategies.1 During limb surgery, re-establishment ofblood flow tourniquet deflation causes transient increase in end-tidal carbondioxide and decrease in mean arterial blood pressure, temperature, and centralvenous oxygen tension. This also induces a paradoxical extension of ischaemicdamages mediated by oxygen free radicals, known as the Ischaemia-reperfusioninjury (IRI).2 IRI causes the release of free oxygen radicals initiate the productionof malondialdehyde (MDA), through the lipid peroxidation of cellular membranes.Following lipid peroxidation, the antioxidant enzyme system is activatedagainst reactive oxygen species (ROS) and attempts to protect cells fromoxidative damage. There is a balance between the scavenging capacity ofantioxidant enzymes and ROS.3 Because of thisbalance, the total antioxidant capacity (TAC) measurement is a sensitive indicatorof the overall protective effects of the antioxidants.5-7
Currently, the preventive role of ischaemicpreconditioning (IPC) is being considered in patients scheduled for total kneearthroplasties (TKA). The authors evaluated twenty patients scheduled for TKAand randomized them as IPC versus placebo. The muscle biopsies of patients inIPC group demonstrated a protective genomic response and increased oxidativestress defense mechanism as compared to placebo.8 However, IPC maynot be possible in all the extremity surgeries.
Literaturedescribes, effective role of a 2 receptor agonist inprevention of release of catecholamine but is inconclusive with regard to IRI effects.In an adult study, brachial plexus anesthesia via axillary approach was performed forupper-limb surgeries. In the dexmedetomidine group, a continuous infusion ofdexmedetomidine (1 microg/kg for 10 minutes, followed by 0.5 mg kg-1 h-1 was used until the end of surgery, whereas thecontrol group received an equivalent volume of saline. Venous blood sampleswere obtained before brachial plexus anesthesia, at 1 minute before tourniquetrelease, and 15 minutes after tourniquet release for biochemical analysis. Dexmedetomidine significantlyattenuated plasma hypoxanthine production in the ischemia and plasma MDAproduction in the reperfusion periods. Blood creatine phosphokinase and uricacid levels were significantly lower in the dexmedetomidine group compared withthose in the control group after reperfusion.14 Recently, Bostankoluand coworkers reported the effects of dexmedetomidine on tourniquet-induced IRIin lower extremity surgeries performed under GA with sevoflurane in adultpatients. Dexmedetomidine infusion versus normal saline was infused at a rateof 0.1μg/kg/minute (-1) for 10 minutes prior to induction and then at0.7μg/kg/hour(-1) until 10 minutes before the end of the operation. Baselineblood samples, at 1 minute before tourniquet release and at 5 and 20 minutesafter tourniquet release (ATR) reported decreased MDA levels when compared withthe basal values and returned to baseline values at 20 minutes after tourniquetrelease. Dexmedetomidine did not have an additional protective role duringroutine general anesthesia.15.
Thepresent study will be a prospective, randomized, placebo controlled trial.
Sample size calculation: In a previous study investigating the tourniquet-induced IRI in lower-extremity operations and assuming that the use of dexmedetomidine would result in 20% reduction in plasma MDA, the present study will require a sample size of 20 patients per group to achieve a power of 80% and α error of 0.05.10 To compensate for possible dropouts, we will enroll 25 patients per group
Afterapproval of the protocol by Institutional Ethics Committee and written informedconsent, 100 patients of either sex scheduled to undergo elective TKA underepidural analgesia + GA will be enrolled.
*Arterial line insertion and blood samples*
Following induction of GA, an anaesthesiologist understrict asepsis will perform arterial line insertion with 20 G arterial cannula.A base line arterial sample of 1 ml will be taken for arterial blood gases(ABG) including lactate and serum sample of 3 ml for MDA. Repeat samples willbe taken at 1 minute before tourniquet deflation, 5 minutes and 30 minutesfollowing tourniquet deflation.
**Group allocation of thepatients**
Using computer generated random number table, patients willthen be randomly allocated to one of the following four groups. Allocationconcealment will be done using coded sealed opaque envelopes and decoding willbe done at the end of the study.
**Group I:** (n = 25) GAmaintenance with propofol 3-5 mg kg-1 hr-1 to maintain an entropy value of 40-60 +IV dexmedetomidine 0.5 μg kg-1 bolusin 10 ml normal saline (NS) over 10 minutes, followed by infusion at the rate0.5μg kg-1 hr-1 ( @10 mlhr-1 ).
**Group II:** (n =25) GAmaintenance with propofol 3-5 mg kg-1 hr-1 to maintain anentropy value of 40-60 + IV 10 ml NS bolus over 10 minutes, followed byinfusion of NS @10 ml hr-1.
**Group III:** (n =25) GAmaintenance with sevoflurane 0.4-2% to maintain an entropy value of 40-60 + IVdexmedetomidine 0.5μg kg-1 bolus in 10 ml NS over 10 minutes,followed by infusion at the rate 0.5μg kg-1 hr-1 ( @ 10 ml hr-1 ).
**Group IV:** (n =25) GAmaintenance with sevoflurane 0.4-2% to maintain an entropy value of 40-60 + IV10 ml NS bolus over 10 minutes, followed by infusion of NS @10 ml hr-1.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- Not Yet Recruiting
- Sex
- All
- Target Recruitment
- 100
American Society of Anaesthesiologists physical status I and II.
Patients with significant cardiorespiratory, hepatic, renal, haematological and neurological dysfunction Patients on beta blockers, anticonvulsants, or any other centrally acting medications Anticipated difficult airway Pregnancy and lactation Patient allergic to the study drug Alcohol or substance abuse.
Study & Design
- Study Type
- Interventional
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method malondialdehyde levels baseline | 1 minute pior to tourniquet deflation | 5 minute and 30 minutes after tourniquet deflation
- Secondary Outcome Measures
Name Time Method Total anti oxidant status Arterial blood gas analysis
Trial Locations
- Locations (1)
Department of Anaesthesia and Intensive Care
🇮🇳Chandigarh, CHANDIGARH, India
Department of Anaesthesia and Intensive Care🇮🇳Chandigarh, CHANDIGARH, IndiaVanita AhujaPrincipal investigator09646121649vanitaanupam@gmail.com