anaesthesia and pthalmology
TRANSCRIPT
Anesthesia for ophthalmic surgeries
Dr. Mohamed Ibrahem El saidM.D.
ContentIOP = intraocular pressureGeneral anesthesia Regional anesthesiaExtra ocular surgeries
IOP = normal 10 - 20
Factors affecting IOP• Increase IOP external pressre
( local anesthesia – face mask – retrbulber hemorrhage) – elevated CVP ( valsalve – MV – trendlenberg position ) increase arterial blood pressure ( valsalva – laryngioscope – straining ) PaCO2 & PaO2 (hypoxia – hypercarbia )
• Anesthetics and IOP inhalational – intavenous all decrease IOP except ketamine
• Sk.ms relaxant no effect except succinyle slight increase
• Anticholinergics = atropine slight increase
Oculo-medullary reflexesOculo-cardiac + respiratory + metric
reflexes• traction on extraocular muscles
med.rectus or pressure on eye ball• trigeminal and vagus • arrhythmia brady.VF .ectopy – resp.
arrest – nausea• Atropine + stop the surgon
General anesthesia in ophth.surg
Aim Slight decrease in IOP Patient refusal for local Eye liable for
complication High myope axial
length > 26 mm Open eye injury Children and young age
Mental disability Lengthy surgeries Coagulopathy
Anesthetic problems Type of patient young pediatric or
geriatric IOP control = optimize bl.pr prevent
straining – optimize CO2 ..... Patient covered and away from
anesthetist Occulo (cardiac - respiratory - metric)
reflexses Postoperative nausea Postoperative analgesia
Preoperative • Pediatric ( cong. heart .
Chest inf...) or geriatric ( syst. Dis. HPT.DM ..)
• Sedative • Anticholinergics &
Antiemetics Intraoperative
• Smooth induction propofol . Fentanyl . Sux or dep.ms.relax
• Tube or LMA + • avoid stress response • Ketamine avoided • Controlled ventilation• Smooth extubation
Postoperative • Analgesia • Nausea and vomiting
Open eye injury• Full stomach • Rapid sequence
induction • Aspiration
prophylaxis • Avoid injury of eye
by mask• Awake extubation Retinal surgery• Lenthy surg• GA preferred• Dark room • Don't use N2O
Regional anesthesia in ophth.surg
Patient selection Concent Examination of fascial n. Andextraocular ms. Preperation for GA Axial length <26 Full investigation Cardiopulmonary resuscitation Full monitors Sedation Sterilization Presence of anesthetist is essential
Types of regional Topical = drops Subconjunctival injection Intracameral = topical +injection in
anterior chamber Subtenon Extraconal = peribulbar Intraconsal = retrobulbar
• Primary gaze position safest • 2.5 ml needle + 2.5 ml solution• lateral 1/3 of lower balberal fissure infro-
temporal quadrent• Iside cone = rapid onset = spinal• Extraconal = slower onset = epidural • You cannot differentiate between both types• Direction of needle superior-medially• Both ways slight movement of needle to
confirm position + needle not attached to globe • After injection needle withdrawal + slight
pressure over globe • Additional fascial nerve may be needed with
intaconal
• Additional fascial nerve may be needed
• Different techniques • A- Van lint subcutanous
around outer canthus • B-O Brien midway
between tragus and lat orbital margin
• C- Nad Bahth injection near mastoid
Complication of local • Occulocardiac reflex • Chemosis, bruising• Retrobulbar hemorrhage• Globe penetration and perforation• Optic nerve damage and atrophy• Extraocular muscle malfunction and injury• Globe ischemia• Central spread Central Nervous System Spread
of Anesthesia = Brain stem anesthesia Loss of conc. Cardiovascular instability Cardiac arrest Vomiting
Hemiplegia Aphasia Convulsions Contralateral
extraocular ms. Palsy
Hemorrhage • Venous
Most common are venous, and bleeding is slowVenous hemo.do not ordinarily threaten vision, the consequences are less severe than arterial hem.and they require no intervention
• Arterialcan be more serious. within a few minutesproptosis and tight eyelids, ecchymosis, chemosis (i.e., conjunctival blood vessel engorgement), blood staining of periorbital tissues, lid swelling, and a dramatic increase in intraocular pressure.Late optic atrophy microvasculature of the optic nerve becomes occluded. A compressive retrobulbar hematoma may threaten retinal perfusion2 by causing central retinal artery occlusion.1