1. Dr S Parthasarathy MD DA DNB PhD Dip. software statistics FICA
Tourniquet
Dr S Parthasarathy MD DA DNB PhD Dip. software statistics FICA

2. Definition
A tourniquet is a constricting or compressing device used to control venous and arterial circulation to an extremity for a period of time.
Venous
Arterial !!

3. History
The word tourniquet itself derives from the French verb tourner (to turn) and was first used by the eighteenth-century French surgeon Louis Petit describing the screw-like device he strapped to the thighs of patients undergoing leg amputations, to reduce blood loss.

4. Taken from the internet for closed academic purpose only

5. Pneumatic – microprocessor controlled
Petit original
Esmarch
Pneumatic manual
Pneumatic – microprocessor controlled

6. Indications Surgery Trauma "Hand surgery without tourniquet is like
repairing a clock in an ink container"
For blood loss
IVRA anesthesia and sympathectomy

7. Contra indications Open fractures Sickle cell disease
Plastic reconstructive surgery done
Sever hypertension
Compartment syndrome and compressions

8. Types Emergency Esmarch Pneumatic Microprocessor controlled
Straight cuffs
Contour cuffs occlude the flow of blood at lower pressures than straight cuffs that are of the same width

9. Parts of tourniquet Inflatable cuff Gas source ( nitrogen or air )
Pressure display
Pressure regulator ( within 2-6 mmHg)
Connection tubing

10. Size 3 inches to 6 inches overlap Width more than half the diameter
Tourniquets should be positioned on the limb at the point of the maximum circumference.
Soft padding – but no loose cotton
The choice of size of tourniquet should allow placement of two fingers between the cast padding and the cuff

11. Exsanguination
Exsanguination before inflation of the tourniquet improves the quality of the bloodless field and minimizes pain associated with tourniquet use.
It is normally done by limb elevation or using an elastic wrap of the extremity.
Malignancy, infection thrombi,fracture – simple elevation or nothing – no wrapping
Rapid inflation – veins and arteries simultaneous

12. Exsanguination and inflation pressures
Maximal exsanguination can be achieved by elevation of the arm or leg for 5 min at 90◦and 45◦ respectively, without mechanical compression.
250 mmHg for upper limb and 300 for lower limb
100 and 150 above systolic for limbs – arbitrary

13. Tourniquet Cuff Pressure
LOP can be defined as the minimum pressure required to stop the flow of arterial blood into the limb distal to the cuff.( limb occlusion pressure)
Safety in kids - ??
Not well defined
Preop LOP

14. Inflation or occlusion time
One hour
Not yet defined but may be up to three hours
10 minute deflation interval every one hour
Double tourniquet and cold extremities – prolong
Pediatric patients – better less than 75 minutes

15. Tourniquet related complications
Systemic
Local

16. Local Normal physiological conduction block in fifteen minutes
Nerve injuries – 0.37%
1 in 6200
upper limb
1 in 3700
Lower limb
Edges of the cuff
Esmarch more – may be 1000 mm Hg
Radial N in Upper limb
Common peroneal N in lower limb more affected

17. Muscle injury
Muscle injury tends to be greatest beneath the tourniquet because of the combination of ischaemia and mechanical deformation, and may persist after tourniquet deflation as a result of micro- vascular congestion
Post tourniquet syndrome – weakness palsy without anesthesia
Three weeks – usually normalize.

18. Skin changes cutaneous abrasions, blisters and even pressure necrosis.
The highest risk of skin injury occurs in: Children, obese, elderly, and patients with peripheral vascular disease
Direct vascular injury is an uncommon complication of tourniquet use.

19. Systemic effects- CVS
Limb exsanguination and tourniquet inflation increase blood volume and systemic vascular resistance that ultimately cause a transient increase in central venous pressure
Systolic BP and diastolic BP with heart rate rise
800 ml – exsanguinated sometimes
How to decrease the rise in BP ?
0.25 mg/ kg of intravenous ketamine

20. After deflation , this may come back to cause hypotension
Arrests after both lower limb deflation reported
Reasons
Post ischemic reactive hyperemia
Anerobic metabolites

21. Respiratory system ETCO2 increase after deflation 1. 6 to 2.4 kpa
This increase is due to the efflux of hypercapnic venous blood from an ischaemic area into the systemic circulation, and an increase in cardiac output following deflation of the tourniquet
Spontaneous – 6n minutes – normal ,, controlled ventilation – a little extra

22. Cerebral
Increased ETCO2 – increased cerebral blood flow in 2 minutes but comes back to normal in ten minutes
Middle cerebra artery blood flow – 50 % rise
Patients where it matters – beware
Hyperventilate before deflation

23. Hematological
Tourniquet inflation during surgery is associated with a global hypercoagulable state.
This is attributable to increased platelet aggregation caused by catecholamines released in response to pain from surgery and the tourniquet itself.
Fibrinolysis after deflation - between - 15 – 30 minutes – may be increased bleeding – increased tissue tpa release
DVT no change if no tourniquet in TKR
Release before wound closure- more blood loss.

24. Excess bleeds intra op
Common causes of intraoperative bleeding include incomplete exsanguination of the limb and a poorly fitting or under- pressurized cuff.
Intraoperative bleeding may also be caused by blood entering through the intramedullary vessels of long bones.

25. Temperature changes
An increase in core body temperature occurs during the inflation of arterial tourniquets because of reduced metabolic heat transfer from the central compartment to the peripheral compartment and also from decreased heat loss from distal skin.
Deflation can cause decrease -- – 0.5 – 1 degrees

26. Metabolic changes
On deflation --- Increased lactic acid, PaCO2,and potassium levels, and decreased levels of PaO2, and pH.
Toxic metabolites produce pathophysiological changes when released into the general circulation.
30 minutes – becomes normal

27. Pharmacology We have isolated the limb
Does administration of some other drug influence
E.g we have applied tourniquet to both lower limbs – will the dose of propofol change ?
So far not studied , but relevance seems less.
Intravenous antibiotics – possible 10 minutes prior to inflation

28. Tourniquet pain Tissue compression – release of prostaglandins
A fbres are blocked by mechanical compression
Mostly “c” fibres
NMDA agonism and central sensitization
Dull aching poorly localized tight pain or discomfort
Increased HR and BP ( touniquet hypertension)
Difficult to prevent and treat this – even in spinal and dense blocks

29. Tourniquet pain 45 minutes usual –
That’s pressure pain – touch sensation should go
Adjuncts – clonidine opioids , adrenaline bicarb
Local anesthetics at the cuff edge , EMLA
Intravenous ketamine, dexmed , remifentanyl,
Magsulf
Preemptive gabapentin
Conversion to GA
Deflate and reinflate

30. Other effects
Post op pain, edemas and infection increased if we do with tourniquet tibia plates and nails
Ream with touniquet - ? Bone necrosis
femur fracture was treated by intramedullary nail, tourniquet use for other lower limb fractures might increase pulmonary morbidity

31. Summary History Types Pressure , time Systemic changes Local changes
Tourniquet pain