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

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 !!

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.

Taken from the internet for closed academic purpose only

Esmarch
Pneumatic – microprocessor
controlled
Pneumatic manual
Petit original

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

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

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

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

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

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

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

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)
Not well defined
Preop LOP
Safety in kids - ??

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

Tourniquet related complications
Local Systemic

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

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.

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.

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

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

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

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

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.

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.

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

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

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

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

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

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

Summary
• History
• Types
• Pressure , time
• Systemic changes
• Local changes
• Tourniquet pain