Anesthetic drug of choice in asthmatic: ( Repeat )
Ans: B (Ketamine) Ref: Miller '? Anesthesia, 7th ed. & Ajay YadavExplanation:KetamineCauses Dissociative anesthesiaPhencyclidine derivativeNMDA receptor agonistAnesthetic PropertiesOnset of Action: 30 - 60 secondsEarly regain of consciousness after 15 - 20 min due to RedistributionElimination half life: 2-3 hoursStrong analgesic propertyMetabolised in Liver and products exreted in urineNot a muscle relaxantPrimary site of action - Thalamo-neo-cortical projectionsCardiovascular SystemIncreases arterial BP,Increases heart rate &Increases cardiac outputIV agent of choice in SHOCKRespiratory SystemPotent BronchodilatorGood induction agent for asthmaticsUpper airway reflexes remain largely intactIncreases salivatory & Tracheo bronchial secretionsUsing glycopyrollate or atropine becomes necessaryCentral Nervous SystemIncreases Intracranial pressure and can precipitate seizuresEmergence reactions:These are seen at emergenceVivid dreamingIllusionsExtracorporeal experiences like floatingExcitementConfusionEuphoriaFearHallucinations:Auditory and Visual hallucinations (Most common side effect of Ketamine)Treated with BenzodiazepineOther SystemsEyeIncrease intraocular tensionPupils dilate moderatelyNystagmusGITIncreases intragastric pressureSalivary secretions increasedMuscluarIncreases muscle toneIncreased non-puposeful movementsDoseCan be given IV. IM, oral. Rectal and intrathecal routeIV -- 2mg/kgIM- 5-10mg/kg AdvantagesInduction Agent of Choke inAsthmaticsShock (HYPOTENSION)Children ( Now Sevoflurance is DOC)Constrictive pericarditisCardiac tamponadeCan be used as SOLE agentCan be used safely at remote places and in inexperienced hands since does not depress heart or respirationPreferred agent when patient is in FULL STOMACH (Preserves laryngo- pharyngeal reflexes)Contraindicated inHead injuryICSOLEye injuryOpthal pathologyIschemic heart diseaseVascular aneurysmPsychiatric diseasesDrug addictsHypertensives
Ketamine
Propofol
Etomidate
Propofol
Anesthesia for Respiratory Disease