bier block (intravenous regional anesthesia)
TRANSCRIPT
BIER BLOCK (INTRAVENOUS
REGIONAL ANESTHESIA)
By: Komal Haleem
(Pharm-D)
Huda Hamid
Amna Tahir
Yoanna David
HISTORY
August Bier introduced this block in 1908.
In 1963, Holmes popularized the Bier Block.
Completed within 40-60 minutes.
Onset of anesthesia is rapid and reasonable
muscle relaxation.
CONDITIONS
1.Surgical procedures involving the arm below the
elbow.
2.Surgical procedures involving the leg below the knee.
Ensure that the patient has been fasting for an
appropriate period of time.
INDICATIONS:
Closed fractures
Burn debridement
Removal of ground-in debris
Abscess I&D
Laceration repair
Foreign body removal
Limited surgical procedures
There appears to be multiple and complementary
mechanisms for producing analgesia and anesthesia.
FACTORS RESPONSIBLE:
A large volume of dilute anesthetic
Ischemia
Asphyxia
Hypothermia
Acidosis
HYPOTHERMIA&ACIDOSIS
Hypothermia and acidosis results in enhanced local anesthetic activity.
ASPHYXIA
Asphyxia occurs at 20-30 mins complementing local anesthetic action.
Local anesthetic molecules transverse venous walls into surrounding tissue.
INJECTION OF LOCAL ANESTHETIC
Initial analgesia produced by local anesthetic action on major nerve trunks, small nerves, and nerve endings.
SEQUENCE EVENTS RESULTING IN ANESTHESIA &
ANALGESIA:
EQUIPMENTS
A standard regional anesthesia tray is prepared with the
following equipment:
22-gauge intravenous catheter
Flexible extension tubing
5" Esmarch bandage
Double cuff tourniquet
20 mL syringes with local anesthetic
Pressure source
A double-cuff tourniquet
PROCEDURE:
1. A small IV intravenous catheter (e.g, 22-gauge) is
introduced in the dorsum of the patient's hand of the
arm to be anesthetized. The patient is in the supine
position.
2. A tourniquet is
placed on the proximal
arm of the extremity to
be blocked. We use a
"double cuff" to increase
the reliability of the
technique and help reduce
the tourniquet pressure pain.
3. Palpate radial and ulnar arteries to establish
baseline.
4. Apply wide Esmarch rubber
bandage to complete the
exsanguination of the
extremity.
5.Elevate arm to promote
venous drainage. The
Esmarch is then unwrapped
and the extremity is checked
for color (pale skin) and
arterial occlusion
(absence of the radial pulse).
6.The extremity is then lowered
and the local anesthetic is
slowly injected through the
previously inserted IV
catheter.
POST PROCEDURE
Analgesia will occur within 3-4 minutes.
Even if the surgery is completed within a few minutes,
on no account should the tourniquet be deflated until at
least 15 minutes has passed.
The pressure in the tourniquet must be constantly
observed and maintained at least 50mm Hg above the
patient's systolic blood pressure.
If the operation is prolonged, the patient may
complain of pain due to pressure from the
tourniquet. This may be reduced either by the
subcutaneous infiltration of a few mls of local
anesthetic above the tourniquet or by the use of a
"double tourniquet technique”.
At the end of the procedure, the tourniquet is
deflated and normal sensation quickly returns.
The tourniquet is reinflated again 20-30 seconds.
ADVANTAGES OF THE BIER BLOCK
Easy to administer
Low incidence of block failure
Safe technique when used appropriately
Rapid onset and recovery
Patient is awake during procedure.
Controllable extent of anesthesia.
DISADVANTAGES OF THE BIER BLOCK
Should be used for only short procedures
Patient may experience tourniquet pain after
20-30 minutes
Sudden cardiovascular collapse or seizures
may occur if local anesthetic is released into
the circulation too early.
Lose pulse
Rapid recovery may lead to postoperative
pain
Difficulty in providing a bloodless field
CONTRAINDICATIONS
Reynaud’s disease
Homozygous sickle cell disease
Young children
Unreliable or inadequate tourniquets.
Shock
Multiple trauma (crush injuries of relevant
limb)
Hypersensitivity to Prilocaine or lidocaine
Seizure disorder
DRUGS
1.PRILOCAINE
The drug of choice as it is least toxic
largest therapeutic index.
One complication is methemoglobinemia . Prilocaine is metabolized to o-toluidine derivatives, which converts hemoglobin to methemoglobin.
onset 2 - 15minute and duration 1 – 4hours.
2.BUPIVACAINE
not suitable
it is too toxic, particularly to the myocardium.
Slower onset .
3.LIGNOCAINE
acceptable alternative.
onset 1.5 - 5minute and duration 1 – 4hours
DOSAGE
the arm dosage can be: 30-40 ml of 0.5%
prilocaine or 0.5 % lidocaine.
In leg, larger volumes 50-60 ml.
COMPLICATIONS
1. Tourniquet pain
2. At IV site: blotchy erythema, flushing, urticaria
3. Tourniquet fails Lidocaine bolus:
Headache, lethargy, slurred speech, seizure
Hypotension, bradycardia
4. Toxicity of local anesthetics
Signs and symptoms may include nausea,
vomiting, dizziness, tinnitus, funny sensation
around the mouth, loss of consciousness.
Local Anesthetic Toxicity Management
Use the A, B, C’s for the management of local
anesthetic toxicity.
A= airway. administer 100% oxygen.
B= breathing. May need to assist the patient with
positive pressure ventilation or intubation.
C= circulation. Check for a pulse..
CONCLUSION
IVRA is a simple and valuable technique that is
easy to learn and perform. It is very safe
provided excessive doses of local anesthetic are
avoided, if the tourniquet pressure is carefully
monitored and if resuscitation equipment is
always immediately available.