（眼科手术麻醉）课件

Anesthesia for Ophthalmic Surgery (眼科手术麻醉),Xuli,Profile and Demands,fine procedure demands,intraocular pressure ( IOP),airway,oculocardiac reflex (OCR),Preoperative Evaluation and Preparation,psychological preparation treatment of the original diseases treatment of the co-existing diseases,Premedication,anticholinegics(抗胆碱药):given intramuscularly, have no significant effects on IOP. However, applied topically to the eye may cause mydriasis (瞳孔散大) and may increase IOP. sedatives(镇静药) analgesics(镇痛药) antiemetics(止吐药),Anesthetic Techniques,.local anesthesia,.general anesthesia,complications of retrobulbar block (将局麻药注入睫状长、短神经及眼球筋膜囊内 ),Important Points in Local Anesthesia,application of Adrenalin,application of sedatives,OCR,Toxicitty of local anesthetics,Important Points in General Anesthesia,careful monitoring,smooth anesthesia,application of muscle relaxants,prevention of OCR,N2O on IOP,anesthetics and IOP,Questions,Whats the main cause of exorbitant IOP during ophthalmic operations? Whats OCR and how to treat it? 青光眼(glaucoma)病人的术前用药、局麻用药及全麻肌松药应用注意事项？ 视网膜脱离修补术中,手术需要往玻璃体内注气，应用吸入全麻药应注意些什么？为什么？,THANK you,Demands,patients cooperation and immobility perfect sedation and analgesia should be availablle. fixation of the eyeball relaxation of the orbicularis oculi muscle(眼轮匝肌 ) and extraocular muscles(眼外肌 ) is necessary.,IOP (眼内压),1、IOP：the pressure on the eyeball wall exerted by the intraocular contents.,3、The main determinant of IOP is the dynamic balance between the production of aqueous humor and its eventual elimination.,2、aqueous humor circulation,4、the main cause of exorbitant IOP is the obstruction of the aqueous humor(房水) circulation.,Several impact facts on IOP,Mydriatic drugs(扩瞳药) Maneuvers (动作行为) Hypercarbia (高碳酸血症) and hypoxia (低氧血症) Pressure on the eyeball Anesthetics:Most anesthetics reduce IOP. Only succinylcholine and ketamine may increase IOP.,Oculocardiac Reflex(OCR) 眼心反射,The OCR is a trigeminovagal reflex(三叉-迷走神经反射) that may be induced by pressure on the eyeball, traction(牵拉) on the extraocular muscle(眼外肌), orbital(眼眶内的) hematoma(血肿), ocular trauma(损伤), and eye pain, manifested by cardiac arrhythmias(心律失常) such as bradycardia(心动过缓), nodal rhythm(结性节律), ectopic beats(异位搏动), ventricular fibrillation(心室纤维颤动), or asystole(心脏停搏).,Local Anesthesia,topical anesthesia(表面麻醉) infiltration anesthesia(浸润麻醉) nerve block(神经阻滞),General Anesthesia,with endotracheal intubation without endotracheal intubation,Anesthetics and IOP,Most general anesthetics are CNS depressants, they lower IOP. But succinylcholine causes a transient (46min) but significant increase in IOP of 10 to 20 mmHg. The effect of ketamine on IOP varies. Early studies reported an increase in IOP after intramuscular or intravenous administration of ketamine. Ketamine given after premedication with diazepam and meperidine (哌替啶) does not affect IOP, and intramuscularly administered ketamine may even lower IOP in children.,N2O on IOP,Ophthalmologists sometimes inject a small bubble of gas (e.g., SF6) into the vitreal (玻璃体的) cavity during reattachment (修补) of the retina (视网膜) so as to hold the retina in place under a long-acting bubble of stable size. N2O is more diffusible than SF6 and more soluble in water, and rapidly enters the gas bubble. Adm