anaesthesia notes for pg

8/17/2019 Anaesthesia Notes for Pg

1/11

45 NOTES TO PG

—Dr. Ankit Yadavendra, M.B.B.S., Dr.V.M.G.M.C., Solapur

6 ANAESTHESIA

hyperpathia=hyperesthesia+ allodynia+ hyperalgesia hypotensive anaesth-orthopedic Sx

ETT thyromental dist>6.5cm sternomental dist>12.5cm adeq mouth opening>3finger breadth(pt) movem of Cx spine

double lumen ETT abs indication-resection of bronchopleural fistula

Mx of preexisting drug Rx herbal medicine, smoking-stop 6-8w bef OCP-stop 4w befMAOI-stop 3w bef clopidogrel-stop 5-7d bef oral anticoagulant(warfarin)-stop 3-5d bef Li-stop 2d bef newer MAOI(selegiline)-stop 1d bef LMW heparin-stop 12-14h bef NPO-solid-6h, liquid-4h, BF infant-solid(milk)-4h,liquid-2h insulin/oral hypoglycemia-omit morning dose

antiHTN(βadr antag)-continue(except ACEI,ARB) aspirin-75mg-continue(except closed space Sx), >75mg-stop 3-5d bef antianginal, anticonvulsive, levodopa, only P pill, steroid-continue abtc-1st-induction anaesth(½-1h bef incision), 2nd-Sx>6h

anaesth machine(1st-1917) Boyle continuous flow anaesth machine

high pressure system cylinder-Mb steel alloy, MRI room-Al

↑ →size -A H typeE O2 cylinder=660l O2 typeD O2 cylinder=470l O2 gas-colour O2-Black Body, white shoulder N2O-blue N2-black CO2-grey air-grey body, black&white quartered shoulder cyclOpRopANE-OrANgE


2/11

He-brown entonox(50%O2+50%N2O)-Blue Body, blue&white shoulder Halothane-Red Enflurane-Orange Isoflurane-Purple Sevoflurane-Yellow(HE IS ROPY)

acetylene-maroon H2-red ARGoN-dARk GReeN ChLOrinE-yELLOw ethylene-purple gas-pin index air-1,5 O2-2,5 N2O-3,5 CO2(>7.5%)-1,6 CO2(


3/11

comm gas outlet wheel-antistatic by add C central supply lines(Cu) gas-colour O2-white N2O-blue

air-black vacuum/suction-yellow DISS(Diam Index Safety System) noninterchang screw for O2&N2O O2 concentrator-zeolite[Al(OH)3] lattice absorb N2 fr air, provide 95%O2,5%argon

circuit open-Schimmelbusch mask-open drop meth-ether,chloroform semiclosed/semiopen-Mapleson system A-Magill circuit-spontaneous ventilation Adult coaxial circuit-Lack[Outer-Insp(LOIS), inner-exp], Penlon, Humphrey ADE, Mera F D-Bain circuit-controlled ventilation(outer-exp, inner-insp) E-Ayre T piece-spontaneous ventilation neonatE F-Jackson Rees modif Ayre T piece-child


4/11

>100kg-6 type-classic(autoclaved-40time), flexometal, intubation/fasttrack, proseal(controlledventillation)

ETT preterm=gestational age(w)/10

1-6mth=2.5-3 6-12mth=3-3.5 1-6y=(age/3)+3.5 6-10y=(age/4)+4.5 adult mal=8-8.5, 21-22cm adult fem=7.5-8, 20-21cm cuff lies midtrachea-(2-2.5cm bel VC) cuff pressure42°C, hypernatremia, c/c ingest alcohol/cocaine/amphetamine↓-old age(6%/10y), opioid, sedation, hypoxia, hypothermia, hyponatremia, a/c ingestalcohol/cocaine/amphetamine↑ ↑MAC- Oil:gas partition coeff, Speed of induction&recovery(MOS)

↑ ↓MAC- bld:gas partition coeff, bld solubility, diffusion coeff (Nani Dur SEE I Hai Meri) N2O(104%)> Desflurane(6.0%)> Sevoflurane(2.0%)> Ether(1.92%)>Enflurane(1.68%)> Isoflurane(1.15%)> Halothane(0.74%)> Methoxyflurane(0.16%) Desflurane-max-speed of onset&recovery, min-B:G partit coeff, bld solubility,diffusion coeff Methoxyflurane-vice versa

elective Sx


5/11

→ →preO2(3-4min)+IV induct+SMR IPPV(bag&mask) ETTemergency(full stom) Sx

→ →preO2(3-4min)+IV induct+SMR(SCh/rocuronium) no IPPV pressure on cricoid→cartilage(Sellick manoevre) cuffed ETT

Brewer Luckhardt reflex

intense pain laryngospasm reflex body movement tachypnoea

preoperative digitalization prevents-intraoperative heart failure, postoperative heartfailure, supraventricular arrhythmia morphine premedication=IM 10mg

↑postanasthetic shivering metab rate by=4time

position in suspected air embolism-head low, rt side up

inf alveolar n infiltration at-3rd molar landmark for lingual site block-mandibular foramen

peak pl conc of LA-intrapleural> intercostal> lumbar> epidural> brachial plex> s/c

neuraxial block spinal needl-pencil tip(Sprotte, Whitacre), nonpencil tip(Quincke)↓dose-old age, preg, abd tm

lingual n block-angle of mandible

postspinal headache last for=7-8d

preanesth med↑atropine- CNS

↓hyoscine(scopolamine)- CNS glycopyrrolate-no effect

pain on IV inj-etomidate> propofol> methohexitone> thiopentone> ketamine(0) speed of recovery-propofol> methohexital> thiopentone> midazolam DRUG

General anaesthetic inhalational volatile liquid-chloroform, diethyl ether, ethylCl, trichloroethylene flurane-methoxyflurane, sevoflurane, halothane, enflurane, isoflurane, desflurane gas-cyclopropane, N2O intravenous barbiturate-thiopentone, methohexital non-barb BDZ-midazolam, diazepam


6/11

phencyclidine-ketamine steroid-pregnenolone etomidate, propofol

IV anaesthetic↓Thiopentone(1934)( all except HR)

yellow, amorphous powder, 6%anhydrous Na2CO3, prepared&stored in N2,↑pH=10.5-11, S- Solubility, metab in liver, pt regains consciousness by redistribution,

microsomal enzyme inducer, releases histamine↓ ↑ ↑ CVS-periph vasodilator, BP, HR, myocard contractility

↓ RS- RR↓ ↓ ↓ ↓ CNS-cerebral vasoconstrictor, cerebral bld flow, ICP, cerebral metab rate, sz

↓ pain- threshold c/i-a/c interm porphyria, variegate porphyria dose-1-6mth infant=7mg/kg, children=5- 6mg/kg, adult=3-5mg/kg(2.5%) onset timevisual), amnesia↑ eye- IOP↑ ↑ GIT- salivary secretion, IAP↑ pain- threshold

c/i-HTN, CAD, aortic aneurysm, head inj, space occupying lesion brain, epilepsy,glaucoma dose=4-10mg/kg IM, 1-2mg/kg IV

PROpofol(1,6-diisopropylphenol)(opposite of ketamine) milky white liq, soyabean oil, glycerol, egg lecithin, metab-liver(70%),lung(30%),highly PROt bound

↓ ↓ CVS- BP, HR

↓ ↓ RS- RR, upper airway reflex↓ ↓ ↓ CNS- ICP, cerebral metab rate, sz↓ GIT- vomiting

antipruritic, antioxidant

neuroleptic analgesia=droperidol(2.5mg)+ fentanyl(50μg) neuroleptic anaesth=droperidol(2.5mg)+ fentanyl(50μg)+ N2O Inhalational anaesthetic


7/11

Ether pungent, irritating to airway, inflammable RS-bronchodil, preserves ciliary activity

↑ pain- threshold m-relax hyperglycemia

c/i-cautery

Ethylene c/i-cautery

Cyclopropane fast induction c/i-cautery

N2O(laughing gas) prepared by heating NH4NO3 at 250°C, 1.5time heavy than air, 35time more soluble

↓in bld than N2, irrevers oxidises Co atom of vitB12& methionine→synthetase&thymidylate synthetase megaloblast anem&periph neuropathy,

nausea,vomiting, teratogenic, not metab by body↑ CVS- pulm vasc resistance

↓ RS- carotid body hypoxic drive↑ ↑ CNS- ICP, cerebral metab rate↑ pain- threshold

c/i-pulm HTN, venous air embolism, pneumothorax, lung cyst, intracran Sx,tympanoplasty, vitreoret Sx

Methoxyflurane(3F atom) vasopressor resist high output ren fail, boiling pt>75°C, hepatitis

Halothane shivering, hepatitis, centrilobular necrosis

↓ CVS-sensitises heart to catecholamine, BP RS-bronchodil

↓ ↑ CNS- hypoxi drive, cerebral vasodil, ICP, potentiat compet NM blocker↓ GIT- hep bld flow&portal bld flow, fatal rate with hepatitis=20-40%

uterus-relax pain-poor analgesic

↑ c/i- ICP, liver dysfn, pheochromocytoma, malign hyperthermia, cardiac arrhythmia

Enflurane

tonic-clonic sz c/i-Epilepsy, renal ds, malign hyperthemia

Isoflurane pungent, coronary steal synd

↓ ↑ CVS-periph vasodilator, BP, HR↑ CNS- ICP

c/i-severe hypovolemia, malign hyperthermia


8/11

Desflurane pungent, eliminat by lung

↑ ↑ CVS- BP, HR RS-irritant to airway, breath holding, coughing, laryngospasm GIT-salivatory c/i-child, malign hyperthermia

Sevoflurane(7F atom) sweet smelling

↑ CVS- QT interval↑ ↑ CNS- sz, ICP

Muscle relaxant centrally acting-BDZ, baclofen, mephenesin, tizanidine, carisoprodol, chlorzoxazone,methocarbamol, orphenadrine, cyclobenzaprine noncompet depol-SCh compet nondepol benzylisoquinolium(curium) short act(10-20min)-mivacurium interm act(20-50min)-cisatracurium, atracurium long act(60-120min)-doxacurium, dtubocurarine, gallamine ammoniosteroid(curonium) short act-ropacuronium interm act-rocuronium, vecuronium long act-Pancuronium, Pipecuronium sugammadex=vecuronium+ pancuronium+ rocuronium

↑SuccinylcHoline(suxamethonium)( all) noncompet, depolarising, no fade on train of 4 stimulus, Hist release, ganglion

↑stimul, K+ level by 0.5mEq/l, RF↑ CVS- BP↑ CNS- ICP

↑ ↑ GIT- IAP, LES tone↑ eye- IOP

c/i-stroke, cerebral palsy, burn, spinal cord inj, m dystrophy dose=2mg/kg onset


9/11

long act, metab by kidn, max histam release, max ganglion block Doxacurium most potent, longest Gallamine cross placenta, metab 100% by kidn c/i-preg, ren fail

aminosteroid-curonium Vecuronium interm act, metab liver, cardiostable Rocuronium most rapid onset, pain on inj Ropacuronium

↑ fastest, bronchospasm in child Pancuronium long acting, vagolytic, sympath stimul, metab by kidn, release histam Metocurine 100% metab by kidn, contain I2 c/i-I2 sensitive pt Gantacurium ultrashort acting Local anaesthetic weak base, block Na ch fr inside, crosses neuronal memb in unionised form,

↑NaHCO3 speed& quality of anaesth

amide(ii) interm act(LMP)-Lignocaine(lidocaine, xylocaine), Mepivacaine, Prilocaine long act-bupivacaine, ropivacaine, dibucaine, etidocaine ester(i) short act-chlorprocaine, procaine long act-tetracaine, benzocaine EMLA=2.5%lignocaine+2.5%prilocaine

Lignocaine conc(%)-block 2-jelly 0.5-IV regional block 1-n block 2-epidural anaesth, urethral procedure 4-topical anaesth 5-spinal anaesth max safe dose=3mg/kg(300mg) without adr, 7mg/kg(500mg) with adr(1:2lac) Bupivacaine long acting, cardiotoxic, more lipid soluble conc(%)-block 0.125-0.5-painless labour 0.5-spinal anaesth, n block max safe dose=2mg/kg with/without adr Prilocaine


10/11

methemoglobinemia Benzocaine methemoglobinemia, allergic rxn Tetracaine highest proT bind, longest Cocaine

periph vasospasm, mydriasis

Opioid Remifentanyl shortest, metab by plasma esterase, equipotent to fentanyl, not given intrathecal

Sufentanil short act, most potent

fentanyl↑ tone of chest m

Buprenorphine ceiling effect

Pethidine c/i-renal failure

Abbreviations a-artery, AA-amino acid, abtc-antibiotic, AI-autoimmune bef-before, bel-below, b/l-bilateral, bld-blood, b/n-between, bn-benign, br-branch,Bx-biopsy ca-carcinoma, carb-carbohydrate, c/i-contraindication, c/l-contralateral,

conc-concentration, cong-congenital, Cx-cervix d-day, def-deficient, ds-disease, d/t-due to, Dx-diagnosis E-estrogen fem-female, fr-from gld-gland, glu-glucose h-hormone idiop-idiopathic, i/l-ipsilateral, inf-infection, inj-injury lig-ligament, LL-lower limb, l/t-leading to m-muscle, maj-major, mal-male, MC-most common, met-metastasis, min-minor,mtx-methotrexate, Mx-management n-nerve, norm-normal P-progesterone, pl-plasma, prot-protein, pt-patient Rx-treatment

SCC-squamous cell carcinoma, sr-serum, Sx-surgery, sz-seizure tm-tumour, ts-tissue UL-upper limb, u/l-unilateral vag-vagina, VC-vocal cord, vel-velocity, vert-vertebra, vit-vitamin, vol-volume w-week, wt-weight Xr-X ray y-year #-fracture


11/11

°-degree

-(N.B.-THESE NOTES ARE ONLY FOR THE PURPOSE OF GUIDANCE AND HELP

TO PG ASPIRANTS, NOT FOR COMMERCIAL OR OTHER PURPOSE. REFERENCE

HAS BEEN TAKEN FROM VARIOUS STANDARD TEXTBOOKS. FOR ANY

FEEDBACK/QUERY PLEASE CONTACT- [email protected] or

[email protected] )

anaesthesia notes for pg

Documents