Presentation on theme: "Intravenous regional anaesthesia Dr. S. Parthasarathy MD., DA., DNB, MD (Acu), Dip. Diab. DCA, Dip. Software statis tics PhD(physiology) Mahatma Gandhi."— Presentation transcript:
Intravenous regional anaesthesia Dr. S. Parthasarathy MD., DA., DNB, MD (Acu), Dip. Diab. DCA, Dip. Software statis tics PhD(physiology) Mahatma Gandhi medical college and research institute, puducherry, India
History Intravenous regional anaesthesia (IVRA) was first described by August Bier in 1908. He observed that when local anaesthetic was injected IV between two tourniquets on a limb, a rapid onset of anaesthesia in between the tourniquets and a slower onset occurred beyond the distal tourniquet. Not popular until the 1960s when it was reintroduced by Holmes.
Indications surgical interventions on the hand, forearm or elbow that will not exceed 1 hour. These include manipulation of forearm fractures, excision of wrist ganglia and palmar fasciotomy. the foot, ankle or lower leg, for example - for removing plates, screws or foreign bodies
contraindications To tourniquet sickle cell disease, Raynaud’s disease or scleroderma Allergy to local anaesthetics peripheral vascular disease Surgery needs tourniquet removal during the procedure
Advantages Ease of performance Safety Onset Relaxation Controlled duration Rapid recovery Definite -- successful anaesthesia in 96– 100%
Disadvantages Use of tourniquet Cannot release tourniquet Exsanguination Toxic reactions Duration ??
Technique - equipment Esmarch bandage Tourniquet – single or double ?? Two IV accesses Routine resuscitative equipment Local anaesthetics
Preparation Explanation IV access both sides Benzodiazepine premed oral Vein on the dorsum of hand access before tourniquet Exsanguination
exsanguination Esmarch bandage or a Rhys-Davis exsanguinator. Crepe bandage elevating the arm for 2–3 minutes while compressing the axillary artery it must be confirmed that no radial pulse is palpable before IV
Tourniquet application The double tourniquet (two tourniquets each 6 cm wide) or a single one (14 cm wide) is applied on the arm with generous layers of padding, no wrinkles are formed tourniquet edges do not touch the skin
Inflation Proximal touniquet 30 mm above systolic Better to have it as 200 mmHg Legs can go upto 300 mmHg
Tourniquet Discomfort Minimum time Release ?? Test deflation and reinflation Resuscitation ready No movement after release
double cuff tourniquet If using a double cuff tourniquet, the distal cuff should be deflated. If required for tourniquet pain control, the distal cuff may be inflated, followed by deflation of the proximal cuff. Check for inflation by palpation of the tourniquet cuff.
Find LOP and inflate LOP can be defined as the minimum pressure required, at a specific time in a specific tourniquet cuff applied to a specific patient’s limb at a specific location, to stop the flow of arterial blood into the limb distal to the cuff Inflate 100 mm above LOP
drugs Prilocaine 0.5 % 40 to 50 ml Lignocaine 0.5 % 40 to 50 ml Ropivacaine, Bupivacaine used Legs upto 70 – 80 ml..dose -- slim?? Preservative free LA Over 90 seconds Chase the LA with NS No adrenaline
Anaesthesia is -- Anaesthesia is terribly simple But sometimes It is simply terrible
Modified methods Hand Legs Foot Children Dose and size of cuff
Complications CNS symptoms 2.1 % to 10 % incidence CVS 15 % ECG changes ?? Minimal drop in BP and HR Dose and preinj. Ischemia Higher levels of local anaesthetic in blood after axillary and lumbar epidural blocks
Cross section of nerve fibre Mantle Proximal area Brachial blocks Core = distal or digital- IVRA Mantle Core Vasa nervorum
Mechanism Digits first even in intercuff method nerves near the elbow (especially the median and ulnar nerves) are known to be closely accompanied by veins, tributaries of which mainly run through the core of each nerve trunk. nerve trunks are constructed with fibres from the periphery nearest the centre
Difference centripetal spread of the anaesthetic effect. Nerve blocks have centrifugal anaesthetic effect because the drug is poured into the nerve from outside