cervical block. spinal anesthesia spinal anesthesia : subarachnoid or intrathecal anaesthetia- the...

Cervical BlockCervical Block

Spinal anesthesia Spinal anesthesia :

Subarachnoid or intrathecal anaesthetia- the drug is injected into subarachnoid

space so it reaches to roots of spinal nerves

Its level in the space is adjusted by using solutions as vehicles with higher (hyperbaric) or lower (hypobaric) specific gravity than that of CSF.

the injection is made ‘heavy” by adding dextrose

or ‘light’ by adding saline. The position of the patient is also

important in limiting the block to the desired level.

e.g. Procaine and lignocaine

This can best be achieved by sitting the patient on the operating table and placing their feet on a stool. If they then rest their forearms on their thighs, they can maintain a stable and comfortable position. The sitting position is preferable in the obese.

Alternatively, the procedure can be performed with the patient lying on their side with their hips and knees maximally flexed. Lateral is better for uncooperative or sedated patients.

Lumbar puncture is most easily performed when there is maximum flexion of the lumbar spine

Epidural anesthesia:

LA is injected outside the dura, as spread of anaesthetic is

restricted to a specific region, it causes fewer complications.

The spinal cord usually ends at the level of L2 in adults and L3 in children. Dural puncture above these levels is associated with a slight risk of damaging the spinal cord and is best avoided. An important landmark to remember is that a line joining the top of the iliac crests is at L4 to L5.

most important most important complications of spinal complications of spinal

anesthesia anesthesia Hypotension : Measures to improve BP- Elevation of the legs or wrapping the Elevation of the legs or wrapping the

legslegs in elastic bandages to increase venous return

Rapid intravenous infusion of fluidsRapid intravenous infusion of fluids for filling the dilated vascular bed; or

Use of vasopressor drugsUse of vasopressor drugs e.g. ephedrine or methoxamine to restore arteriolar and venous tone.

Headache- It is probably due to leakage of CSF

from site of puncture and it responds to analgesic drugs.

Other complications - post-operative urinary retention

and intestinal atony.

LignocaineLignocaine

Most commonly employed local anestheticIt is stable, can be stored for a long time at room temperature and can be autoclaved repeatedlyQuick onset of actionHigh degree of penetrationExcellent surface anestheticFollowing infiltration of 0.25-0.5% solution, the duration of action varies between 30 and 60 minutes.

Addition of adrenaline (1 in 200,000) prolongs the action for about 2 hours.Analgesia is complete within a few minutes and recovery occurs quickly, within 2-3 hours after spinal anesthesia

USESUSESRecommended for: topical use, nerve blocks, infiltration epidural injection and for dental analgesia. in subjects allergic to procaine and other ester-type local anestheticsLignocaine -give good muscle relaxation, allow the use of cautery and electrical appliances during surgery

Bupivacaine Bupivacaine (Marcaine):- This local anesthetic is about four times as potent as lignocaine and has more prolonged action (up to 8 hours)

Cinchocaine Cinchocaine ( Nupercaine)( Nupercaine)

a potent but toxic local anesthetic. It is not used for infiltration or nerve block anesthesia. It can be used locally in the form of ointment as light and heavy solutions for spinal anesthesia

FentanylFentanyl

Spinal opioid analgesiaSpinal opioid analgesia Intrathecally produces analgesia without sensory loss. This technique is sometimes used for relief of chronic pain such as that of cancer.