REGIONAL ANAESTHESIA Katarina Zadrazilova FN Brno October 2010 Anaesthesia = loss of sensation •General (narcosis) •Local / regional • •Combined Local anaesthetic •Reversible block • •Sodium ion canal (Na+ to cell) • •A: myelinated ▫a (alfa): motor function, reflex activity a proprioception ▫b (beta): touch, pressure ▫g (gama): muscular tonus ▫d (delta): PAIN and sense of heat •B: thin, myelinated preganglion-nerve fibre, autonomic function, smooth muscle of vessels •C: non-myelinated, PAIN Nerve fibre Nerve block - signs • •(B fibre) block of sympaticus = heat •(C + Ad fibre) block of pain and heat •(Ab) loss of touch sensation •(Aa) motor block Local anaesthetics •Potentially toxic! •CNS ▫Convulsion, coma, depression of breath! –Perioral tingling, iron taste, somnolence, vertigo, tinitus (ringing), nystagmus, visual disturbance •Cardiovascular system ▫Hypotension, bradycardia, colaps of circulation, asystoly or ventricular fibrilation! Local anaesthetics •Esters •Amides • •Examples: lidokain, trimecain (Mesocain), • bupivakain (Marcaine), prokain, • artikain (Ultracain, Supracain), • ropivakain (Naropin) When to use regional techinques 1.Patient safety – frail elderly, comorbidities 2.Patient satisfaction – ealy oral intake, no PONV, no sore throat 3.Surgical outcome - awake craniotomy • Most common regional anaesthesia •Caesarian section ▫Patient safety –Control of airway ▫Patient satisfaction –Awake during the delivery of the child –Presence of partner ▫Surgical outcome –Intraoperative bleeding is reduced –Reduced stress response Local anaesthesia •Local anaesthesia ▫ Superficial (topic, mucosa) ▫ ▫Infiltration • 1_01 4_12 1_02 Central neuroaxial block •Epidural •Subarachnoideal (spinal) 1_08 1_06 Anatomy of spinal cord •7 C, 12 Th, 5 L, 5 S a 4-5 Co •spinal cord L1/2 •spinal cord cover • (pia mater, arachnoidea, dura mater) •ligamneta (ligg. supra- , interspinalia, • lig. flavum) • •epidural a subarachnoid space Skin dermatomas spinal3 Central neuroaxial block •Indication: ▫Surgery bellow umbilicus ▫Combined anaesthesia for abdom. surgery ▫Continual technic for postoperative pain relief ▫Labour analgesia and anaesthesia •Contraindication ▫Patient´s refusal ▫Local infection ▫Hypotension, hypovolemia, shock ▫Valve stenosis - fixed cardiac output ▫Coagulopathies (warfarin, heparin) Systemic effect of central blockade •Cardiovascular system ▫Sympathetic block –Hypotension –Reduced venous return –Relative hypovolemia •Ventilation: small influence •Urination: urinary retention 3_02 3_04 3_05 3_03 Epidural anaesthesia •Epidural space ▫posterior border: lig. flavum + vertebral arches ▫Content: fat connective tissue, lymphatic vessels, vessels for vertebra and spinal cord, radices of spinal nerves, spinal cord, spinal covers ▫thickness of epidural space> –lumbar: 5 - 6 mm –thoracic: 3 - 5 mm –cervical: about 3 mm Epidural anaesthesia •Spread of anaesthetics: ▫Both direction from the end of needle or catheter •Dose: 2 ml per segment •Density of block depends on the concentration of LA used • Equipment 3_16 Lumbal epidural block [USEMAP] Cervical epidural Peripheral blocks •Single nerves •Nerve plexuses Plexus brachialis 1_01 1_03 Stimulator 3_15 3_08 5_04 6_07 7_07 Questions ?