MACKENZIE KUHL, DOMARQUETTE GENERAL HOSPITAL

AUGUST 2013

Regional Techniques

Regional Techniques

Neuraxial nerve blocks Spinal anesthesia Epidural anesthesia

Peripheral nerve blocks Upper extremity (Brachial plexus blocks)

Axillary nerve block Supraclavicular nerve block Interscalene nerve block

Lower extremity Femoral nerve block Sciatic nerve block Popliteal nerve block

Neuraxial techniques

Neuraxial techniques are used for pain control for operative anesthesia, obstetric anesthesia, and chronic pain management

Spinal Single shot technique in which local anesthesia +/-

narcotic is placed into the subarachnoid space, used for surgical anesthesia

Epidural Catheter based technique in which local anesthesia

+/- narcotic is placed into the epidural space, mainly used for postoperative pain control

Spinal Anesthetic

Local anesthetic +/- narcotic placed in subarachnoid space

Usually done at lumbar vertebrae (L3-L4, iliac crests)

Dermatomal level T4 level for C-section T10 level for hip and knee procedures

Lidocaine 1 hour duration

Bupivacaine 2-3 hours duration

Dermatomal patterns

Neuraxial techniques

Catheter placed in the epidural space under aseptic conditions

Epidural Anesthetic

Catheter based technique in which local anesthetic +/- narcotic is placed in epidural space

Usually done at lumbar and thoracic vertebrae for postoperative pain control (cervical nerve roots for chronic pain management)

Catheter being placed

Indications for neuraxial techniques

Orthopedic Total knee and hip arthroplasties, ankle surgeries

General Exploratory laparotomies, breast cancer surgeries

Vascular AAA repair

Genitourinary TURP’s, nephrectomies, open prostatectomies

Obstetric Cesarean section

Absolute contraindications to neuraxial anesthesia

Infection at the site of injectionPatient refusal or inability to cooperateCoagulopathy or other bleeding diathesis

Platelets>100,000 and INR <1.4Severe hypovolemiaIncreased intracranial pressureSevere mitral/aortic stenosisAllergy to local anesthetics

Complications of neuraxial techniques

Physiologic responses Urinary retention Hypotension High block Nausea Pruritus

Related to needle/catheter placement Backache Postdural puncture headaches Neural injury Catheter shearing or tearing Inflammation Infection Bleeding

Drug toxicity TNS Cauda equina syndrome Systemic local anesthetic toxicity Respiratory depresssion

ASRA guidelines

Subcutaneous UFH (5000U BID) Twice daily dosing (5000U)

No contraindication to neuraxial technique Because HIT may occur, ASRA recommends that patients receiving

heparin for more than 4 days receive a platelet count prior to epidural placement or removal

Thrice daily dosing Must weigh risks vs benefits on individual basis

LMWH Once daily dosing (40mg SQ)

Must wait 12 hours from last dose for neuraxial technique Twice daily dosing

Must wait 12 hours from last dose for neuraxial technique, must remove epidural catheter postoperatively before instituting

Dabigatran Must wait 72 hours prior to neuraxial procedure

Benefits

• 528, 495 patients undergoing primary knee or hip arthroplasty Memtsoudis, et al. Anesthesiology May 2013; 118: 1046-1058

Decreased 30 day mortality Decreased prolonged length of stay Decreased transfusion requirements Decreased in-hospital complications

Pulmonary embolism Pulmonary compromise CVA Acute renal failure

Benefits

Reduction of postoperative mortality and morbidity with epidural or spinal anesthesia: results from overview of randomized trials (9559 patients) Rodgers, et al. BMJ December 2000; 321(7275): 1493

Decreased DVT by 44% Decreased PE by 55% Decreased transfusion requirements by 50% Decreased pneumonia by 39% Decreased respiratory depresion by 59% Decreased myocardial infarctions

Benefits

Anesthetic Technique for Radical Prostatectomy Surgery Affects Cancer Recurrence, Biki, et al. Anesthesiology Aug 2008; 109: 180-187

Open prostatectomy with GA plus epidural postoperative analgesia was associated with less risk of biochemical cancer recurrence

Why?

Altered coagulationIncreased blood flowImproved pulmonary mechanicsReduction in surgical stress responses

Peripheral nerve blocks

Peripheral nerve blocks Upper extremity (Brachial plexus blocks)

Axillary nerve block Supraclavicular nerve block Interscalene nerve block

Lower extremity Femoral nerve block Popliteal nerve block Sciatic nerve block

Peripheral nerve blockade

Primary anesthetic for peripheral limb surgery Mainly done with direct visual ultrasound and nerve

stimulation Inject local anesthesia around nerves to obtain surgical

anesthesia or postoperative pain control Benefits

Excellent pain control Decreased narcotic use

Risks Bleeding Infection Nerve damage Systemic local anesthetic toxicity

Brachial plexus

The brachial plexus is responsible for cutaneous and muscular innervation to upper arm except with two exceptions:

The trapezius muscle innervated by the spinal accessory nerve and an area of skin located in the axilla which is

innervated by the intercostobrachial nerve

Brachial plexus blockade

Axillary nerve blockSupraclavicular nerve blockInterscalene nerve block

Axillary nerve block

Anesthesia to arm, elbow, FOREARM and HANDBlocks median, ulnar and radial nervesUsually misses musculocutaneous

nerve, must block separately

Axillary nerve block

Supraclavicular nerve block

Anesthesia to ARM, ELBOW and hand (“spinal of upper extremity”) Blocks median, ulnar and radial nerves Risk is pneumothorax

Supraclavicular nerve block

Interscalene nerve block

Anesthesia to SHOULDER, upper arm and elbow Blocks median, ulnar and radial nerves Patients may develop ipsilateral Horner’s syndrome

and diaphragmatic paralysis (due to phrenic nerve block)

Interscalene nerve block

Lower extremity nerve blocks

Femoral nerve blockSciatic nerve blockPopliteal nerve block

Femoral nerve block

Anesthesia to anterior thigh and anterior knee

Femoral nerve block

Anesthesia to anterior thigh and anterior knee

Sciatic nerve block

Anesthesia to posterior aspect of the thigh, hamstring, part of hip and knee joint, and the entire leg below the knee except for medial aspect of lower leg (innervated from saphenous nerve)

Popliteal nerve block

Anesthesia for ankle and foot surgery