- Tourniquets consist of an inflatable cuff that is wrapped around a limb and inflated to compress blood vessels. They are used in surgery to reduce blood loss by temporarily stopping blood flow to the limb. - The appropriate tourniquet pressure varies depending on the limb and individual patient factors. Pressures that are too high can cause nerve damage while pressures that are too low may not fully stop blood flow. - Prolonged tourniquet use over 2 hours can lead to muscle damage from ischemia. Periodic reperfusion is recommended if the tourniquet must be used for an extended time. Tissue damage and systemic effects increase with longer duration of tourniquet inflation.

1. ARTERIAL
TOURNIQUET
Dr Nisar Ahmed Arain
Assistant Professor
Anesthesia/Critical Care/ER

2. -TOURNIQUETS
Pneumatic tourniquets
--consists of three basic components
--1-A cuff, similar to a blood pressure cuff, which
is wrapped around a patients limb and then
inflated
--2-A compressed source
--3-Pressure gauge, designed to maintain
pressure in the cuff at a set value.
Automatic Tourniquets
--Allow the intended pressure to be preset before
inflation and have controllers that compensate
for small leaks

3. -TOURNIQUETS

4. -TOURNIQUETS

5. -ARTERIAL
TOURNIQUETS
-USES
--1-Extremity surgery to reduce blood loss and provide good operating conditions
--2-For intravenous regional anesthesia (Biers Block)
--3-For intravenous regional sympathectomy in the management of complex
regional pain syndromes and for isolated limb perfusion in the management
of localized malignancy

6. -TOURNIQUET PRESSURES
TOURNIQUET PRESSURE :
--1--50 to 100 mm of Hg above the systolic blood
pressure
--Upper limb 250 mm Hg
--Lower limb 350 mm of Hg
DOPPLER OCCLUSION PRESSURE (DOP)
--1-Upper limb DOP + 50 mm of Hg
--2-Lower limb DOP + 75 mm of Hg above the DOPR
--3-Upper limb 135 to 255 mm of Hg
--4-Lower limb 175 to 305 mm of Hg

7. -SPECIFICATIONS OF TOURNIQUET
TOURNIQUET TIME
--Initial time 90 minutes and ideal is 45 to 60 minutes
--If more then 2 hours deflate cuff for 5 minutes for
perfusion
WIDTH OF THE CUFF
--Standard width is 8,5 cm
--15 cm conical shaped procedures sub systolic pressure
required to stop detectable flow
ISCHEMIC TIME INFORMATION TO
SURGEONS
--First two hours – Half hourly intervals
--Next at 2.5 hours
--Next every 15 minutes interval there after

8. -PATHO PHYSIOLOGY

9. -PATHOPHYSIOLOGICAL EFFECTS
--1-All arterial tourniquets, including the two
automatic devices, can be associated with
complications ranging from the minor and
self timing to the debilitating even fatal.
--2-Systemic effects are usually related to
inflation and deflation of tourniquet
--3-Local effects and complications may result
from either direct pressure to the
underlying tissues or ischemia in tissues
distal to the tourniquet

10. -NERVE INJURY
DUE TO TOURNIQUET PRESSURE
--1-Most common complications
associated with tourniquets are
ranging from
“Paresthesia to Paralysis”.
--2-The RADIAL nerve followed by the
ULNAR and MEDIAN nerves in the
Upper limb
--3-The SCIATIC nerve in the lower limb
are most commonly involved and it
would appear s that large diameter
nerve fibers area more commonly
affected

11. -ESMARCH BANDAGE
--1-This increases the cause of Nerve injuries and this may
explain the fact that nerves are more susceptible to
mechanical pressure
--2-The effects of nerve compression at the tourniquet site
may make injury caused by ischemia or surgical trauma
at a more distal site

12. -PREVENTIVE MEASURES
--1-Tourniquets use only recommended time
--2-Check accuracy of the pressure
--3-Effective pressure to achieve limb occlusion
pressure
--4-Use a cuff which properly fits the Extremity

13. -MUSCLE INJURY
--1-Muscle injury is caused by ischemia beneath and
distal to the cuff
--2-Combination of ischemia and mechanical
deformation of the tissue
--3-The extent of damage is related to the duration of
ischemia
--4-With the time the intracellular concentrations of
-Creatine
-Phosphate
-Glycogen
-ATP and
-Oxygen decreases

14. -MUSCLE INJURY effects contd.
--5-Creatine phosphate is depleted by two hours and the ATP
supply is exhausted by 3 hours
--6-Lactate and potassium concentrations and the PaCO2
increase with increasing duration of ischemia
--7-Intracellula Ph decreases – sometimes a pH of 6.0 is
reached after 4 hours of continuous pressure
--8-Intravenous pH in the limb decreases and a pH of 6.9
corresponds to the fatigue point of muscle

15. -MUSCLE INJURY effects contd.
--9-Further ischemia may produce irreversible muscle damage
--10-After 2 hours at 200 to 300 mm Hg, histological changes
--e.g
--Inflammatory cells
--Focal necrosis
--Regional necrosis and
--Hyaline degeneration
These may be seen in the muscle beneath the cuff
--11-Significant increase in ”xanthene oxidase” activity in both
Local and Systemic blood

16. -POST TOURNIQUET SYNDROME
--1-The combined effect of muscle ischemia,
edema and Microvascular congestion
--2-The affected limb is stiff, pale, weak but not
paralyzed and subjectively numbness without
objective anesthesia
--3-Prolonged bleeding from surgical wound
--4-It typically resolves over 1 to 6 weeks

17. -COMPARTMENT SYNDROME
--1-Relative complications of tourniquet
--2-External and Internal pressures – pain
--3-Tense skin, swelling, weakness, paresthesia.
--4Absent pulse – irreversible paralysis
CAUSES and PREVENTION
--1-Trauma or surgery
-Time
-pH
--2-Capillary permeability, Prolongation of dotting
--3-Pre- operative evaluation
--4-Time < 90 minutes

18. -COMPARTMENT SYNDROME
-CAUSES and PREVENTION
--5-Routine tourniquet use results in weakness and delayed
post operative recovery.
--6-Greater pressure produce greater functional impairment
--7-Fst twitch fibers are affected more then slow twitch fibers
--8-Wide, properly fitting cuffs require lower inflation pressure,
which may reduce muscle injury

19. -PREVENTIVE MEASURES
COMPARTMENT SYNDROME
--1-Should it be necessary to use a tourniquet for
longer than 2 hours
--2-It is recommended that the limb be Re-Perfused
periodically to allow for metabolic recovery of the
muscle and maintenance ATP levels
--3-Recommendations vary from 10 minutes hourly to
15 to 20 minutes every 2 hours

20. -VASCULAR INJURY
COMPARTMENT SYNDROME
--1-Vascular injuries are rare
--2-They are usually associated with
peripheral vascular disease and
fractures of Atheromatous plaques
by pressure
--3-Plaque dislodgement
--4-Thrombus due to ack of blood flow

21. -SKIN INJURY
--1-Skin injuries are common, Esmarch bandages twist
and stretch the skin
--2-While pressure Necrosis and sharing have been
described with pneumatic Tourniquets because
of inadequate padding or improper application
--3-Chemical burns have been reported with alcohol
based cleansing solutions held against the skin
under pressure
--4-Friction burns from the movement of a fully inflated
Tourniquet over bare skin

22. -HAEMATOMAS/BLEEDING
--1-Because of Tourniquet inflation, bleeders may not
be identified intra-operatively
--2-Once the Tourniquet is released, a hematoma may
develop or there may be a potential for acute
blood loss super-imposed on the hemodynamic
changes of Tourniquet release
--3-Tourniquet release for hemostasis has actually
been shown to increase bleeding
--4-Haematomas, arterial injuries and a compartment
syndrome may all result in a delayed return of
blood flow

23. -TOURNIQUET FAILURE
--1-Bleeding may occur despite a properly applied and
inflated Tourniquet, in a patient with non-calcified
vessels
--2-This is the phenomenon of tourniquet ooze
--3-Blood bypasses the Tourniquet through the medulla of
the humerus or femur. It typically starts about 30
minutes after Tourniquet inflation.
--4Increased the Tourniquet pressure does not help
--5-Other causes of inadequate hemostasis include arterial
and venous leakage due to inadequate pressure, calcified
incompressible vessels and inadequate

24. -SYSTEMIC EFFECTS
-CARDIOVASCULAR SYSTEM
--1-Cardio-vascular features are related to all stages of
Tourniquet use, from exsanguination to inflation
maintenance and deflation
--2-Limb exsanguination and subsequent Tourniquet
inflation increase blood volume and systemic vascular
resistance
--3-CVP increases by upto 14 to 15 cm H2O and blood
volume by upto 800 ml following exsanguination of
both legs
--4-The changes in CVP and BP may be transient or may
be maintained until Tourniquet release

25. -TOURNIQUET PAIN
--1-Approximately 30 to 60 minutes after Tourniquet inflation,
Heart rate and Blood pressure increase this is due to
Tourniquet Pain
--2-An awake patient will complain of a vague, dull pain that
becomes so severe as to be unbearable
--3-It will occur despite an adequate sensory level.
--4-The incidence increases with increasing age and duration
of surgery and with lower limb surgery

26. -TOURNIQUET PAIN contd.
--5-The Pain is probably mediated by the unmyelinated, slow
conducting C fibers
--6-The A-Delta fibers are blocked by mechanical compression
after about 30 minutes, while the C-fibers continue to function
--7-Methods used to try to decrease the incidence of pain include
the addition of adrenaline to the local anesthetic, the type of
local anesthetic. Addition of clonidine or morphine and
alteration of the dose of local anesthetic has very good action
--8-The onset of “Tourniquet Pain” has been delayed by the
application of EMLA cream to the tourniquet site and by this
method pain feeling is reduced

27. -TOURNIQUET PAIN contd.
--9-With Tourniquet deflation, CVP and MAP decrease reaching
to a maximum at 3 minutes and taking approximately
15 minutes to return to the normal value
--10-The decrease is the result of combination of a shift of the
blood Back into the limb, a post-ischemic reactive Hyperemia
bleeding from non ligated vessels and washout of the
metabolites from the ischemic areas into the systemic
circulation.
--11-The cardiac index increases to compensate, mainly by an
increase in the myocardial inotropic state
-12-The Mean decrease in systolic blood pressure is 14 to 19 mm
Hg and the mean increase in Heart rate is 6 to 12 bpm

28. -RESPIRATORY EFFECTS
--1-As thee Tourniquet is deflated and the limb Re-perfuses,
CO2 and metabolites e.g Lactate are returned to the
systemic circulation
--2-The End tidal CO2 (ETCO2) increases by 0.75 to 18 mm Hg
and
-Lower limb is > upper limb and
-Men > women, because of mans greater muscle bulk

29. -RESPIRATORY EFFECTS contd.
--3-The ETCO2 peaks at 1 to 3 minutes, and then returning
to base line at 10 to 13 minutes in a spontaneously
breathing patient.
--4-The increase in ETCO2 will be prolonged in mechanically
ventilated patients unless the minute volume is
increased
--5-The mixed venous saturation decreases transiently
but a drop in the arterial saturation is un-usual

30. -CEREBRAL
CIRCULATORY EFFECTS
--Middle cerebral Artery flow increases after Tourniquet
deflation related to the increased ETCO2
--This increase is larger with lower limb surgery than with
upper limb
--Patients with reduced intracranial compliance may be at
a higher risk for adverse effects related to the increase
in cerebral blood flow
--Maintenance of normocapnia prevents this increase

31. -HAEMATOLOGICAL EFFECTS
--1-The Tourniquet causes changes in both coagulability
and fibrinolysis.
--2-Tissue damage induces coagulation factors and
activates platelets. Pain (surgical and Tourniquet)
provokes catecholamine release, exacerbating the
state of hyper-coagulability
--3-Tissue ischemia causes tissue plasminogen activator
release, activating the antithrombin 111 and
thrombomodulin – protein C anticoagulant
system in the affected limb

32. -HAEMATOLOGICAL EFFECTS contd.
--4-Patients at high risk for deep vein thrombosis (DVT) and
Pulmonary Embolism Include those with lower limb
trauma, prolonged immobilization (.>3 days) or a
history of DVT’s
--5-Venous Embolism is common after tourniquet deflation
--6-The Embolus may consists of air, Marrow contents, Clot
or Cement
--7-Increased incidence of pulmonary emboli in total

33. -SICKLE CELL HAEMOGLOBINOPATHY
--1-Sickling is predisposed to by
-Circulatory stasis
-Acidosis and
-Hypoxemia
All of these happen with the use of Tourniquet
--2-Systemic release of anaerobic metabolic products
with cuff deflation may also induce sickling
--3-Intravascular sickling may therefore theoretically
occur with Tourniquet use in susceptible patients

34. -TEMPERATURE CHANGES
--1-In both adults and children, core temperature increases during
tourniquet use
--2-Tourniquet inflation decreases heat transfer from the central
to the peripheral compartment, decreases the surface area
available for heat loss and decreases the heat loss from the
distal skin, allowing the temperature to rise

35. -TEMPERATURE CHANGES contd.
--3-The increase in temperature may sometimes be
larger than predicted slow release of ischemic
metabolites, which raise the temperature may
occur via the bone
--4-In children the temperature may rise by as much
as 1 to 1.7 Degree Centigrade. After cuff deflation
a “Re- distribution hypothermia” may occur as the
cold extremity is Re-perfused

36. -METABOLIC CHANGES
--1-With Re-perfusion of the affected limb, Potassium,
Lactate, CO2 and the other ischemic metabolites
are washed into the systemic circulation
--2-Potassium and Lactate concentrations increase for
approximately 30 minutes and pH decreases
transiently.
--3-Oxygen consumption (VO2) increases by 55% and
CO2 production (VCO2) by 80% 2 minutes post release
--4-This increase in VO2 provides the energy needed to
replenish both the high energy Phosphate and oxygen
stores depleted during ischemia and the energy needed
is fulfilled to some extent

37. -DRUG KINETICS
--1-Tourniquet inflation isolates the limb from
the rest of the body, Altering the volume of
distribution, sequestering drugs in the limb
(If given before inflation) or preventing them
from reaching the limb
(If given after the inflation)
--2-To prevent post operative infection,
prophylactic antibiotics need to reach the
tissue in-Adequate concentrations before
tourniquet inflation - for this atleast
5 minutes is required

38. --3-Fentanyl and Midazolam sequestered in
the limb are released into the systemic
circulation after cuff Deflation
--4-These increased levels may be clinically
significant, especially in the elderly, and
prolonged post-operative observation
(upto 4 hours) is necessary.
-DRUG KINETICS contd.

39. --1-Perpheral vascular disease
--2-Severe trauma to the limb
--3-Head injury / CNS disorder
-Peripheral Neuropathy
--4-Severe infection of the Limb
--5-DVT in the limb
--6-Severe arthritic changes
-Bony spurs
-Previous fracture of the limb
--7-Poor skin condition of the
limb
--8-Arteriovenous (AV) fistula
--9-Lack of appropriate
equipment
-10-Sickle cell Hemoglobinopathy
-CONTRA-INDICATIONS