The Medical Student’s Anesthesia Pocketbook
University of Texas Texas Health Science Center Houston
Table of Contents ACKNOWLEDGEMENTS...........................................................................................................................2 ANESTHESIA
OVERVIEW.........................................................................................................................3
.............................. ..................... ..................... ..................... ..................... .................... ..................... ..................... ..................... ....................................3 .........................3 INTRODUCTION.................... ............................... ..................... ..................... ..................... .................... ...................................3 .........................3 PREOPERATIVE HISTORY AND PHYSICAL.................... IV’S AND PREMEDICATION ......................................................................................................................... .............................. ..................... ..................... ..................... ..................... ..................... ..................... ................................ ...................... R OOM OOM SETUP AND MONITORS .................... INDUCTION AND INTUBATION.....................................................................................................................! MAINTENANCE.........................................................................................................................................."# EMERGENCE.............................................................................................................................................."" PACU CONCERNS ......................................................................................................................................"$ COMMONLY USED MEDICATIONS......................................................................................................13 VOLATILE ANESTHETICS .........................................................................................................................."3 IV ANESTHETICS ......................................................................................................................................."% ............................... .................... ..................... ..................... ..................... ..................... .................... ..................... .................................."& ......................."& LOCAL ANESTHETICS ..................... ............................... .................... ..................... ..................... ..................... ..................... .................... ..................... ..................... ..................... ..................................."& ........................"& OPIOIDS..................... MUSCLE R ELAXANTS ELAXANTS ................................................................................................................................" ............................... .................... ..................... ..................... ..................... ................................." ......................" R EVERSAL EVERSAL AGENTS / ANTICHOLINERGICS..................... PHARM CHARTS........ CHARTS................... ..................... ..................... ..................... .................... ..................... ..................... ..................... ..................... ...........................................18 .................................18 INHALATIONAL ANESTHETICS .................................................................................................................."' MAC.........................................................................................................................................................."' INTRAVENOUS ANESTHETICS ...................................................................................................................."! IV
FLUIDS....................................................................................................................................................2
ASA
CLASSIFICATION.............................................................................................................................21
MALLAMPATI CLASSIFICATION.........................................................................................................22 !UICK
REFERENCE/REVIEW...............................................................................................................23
PROCEDURE
CHECKLIST......................................................................................................................2"
INTUBATION...............................................................................................................................................$( IV LINE PLACEMENT .................................................................................................................................$( ................................ ..................... .................... ..................... ..................... ..................... ..................... ....................................$( ..........................$( BAG MASK V VENTILATION..................... ............................... .................... ..................... ..................... ..................... ..................... .................... ..................... ...............................$' ....................$' VENTILATOR S SETTINGS..................... ARTERIAL LINE PLACEMENT ...................................................................................................................$' CENTRAL LINE PLACEMENT....................................................................................................................$' SPINAL.......................................................................................................................................................$! EPIDURAL..................................................................................................................................................$! RESOURCES................................................................................................................................................3 NOTES...........................................................................................................................................................31
Trent Bryson MS4, Tanner Tanner Baker MS4, Claudia Moreno MS4, C#$%&'()%#&*: Trent Darrell Wilcox Wilcox MS3, and Allison DeGreeff MS3
Ackno)led*e+ents ,e the contributors )ould first and fore+ost like to thank the faculty at the University of Texas at Houston for their su--ort *uidance and teachin*s in hel-in* us create this -ocket book. ,e )ould also like to thank the residents for their contributions to our learnin* and skill develo-+ent as )ell as in hel-in* us revise the content to be as detailed succinct and accurate as -ossible.
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Anesthesia /vervie) Ada-ted fro+ 0A Medical Student’s Anesthesia Pri+er1 by 2oy . Soto M4 5roysoto6ucla.edu7
I$%&#+),%'#$ 8n +any -ro*ra+s across the country +edical students are only ex-osed to t)o )eeks of anesthesiolo*y durin* their third or fourth year. The student often attends daily lectures and +i*ht be told to 9read Miller:s ;asics of Anesthesia9 but often by the ti+e the student has finally fi*ured out )hy )e are doin* )hat )e:re doin* the rotation is over and he or she leaves )ith only a +ini+u+ of anesthesia kno)led*e.
This -ri+er is intended to *ive a brief overvie) of )hat )e do )hen )e do it and )hy )e do it for standard unco+-licated cases ... the ty-es that you are bound to see durin* your rotation. ;y no +eans is the infor+ation contained co+-rehensive or intended to allo) you to -ractice anesthesia solo but it is intended to *ive an overvie) of the 9bi* -icture9 in a for+at that can be
P ours is +uch +ore focused )ith s-ecific attention bein* -aid to the air)ay and to or*an syste+s at -otential risk for anesthetic co+-lications. The ty-e of o-eration and the ty-e of anesthetic )ill also hel- to focus the evaluation.
/f -articular interest in the history -ortion of the evaluation are? Coronary Artery Disease @ ,hat is the -atient:s exercise tolerance Ho) )ell )ill his or her heart sustain the stress of the o-eration and anesthetic Askin* a -atient ho) he feels 5i.e. S/; CP7 after cli+bin* t)o or three fli*hts of stairs can be very useful as a 9-oor +an:s stress test9. Hypertension @ Ho) )ell controlled is it 8ntrao-erative blood -ressure +ana*e+ent is affected by -reo-erative blood -ressure control. Ast!a @ Ho) )ell controlled is it ,hat tri**ers it Many of the stressors of sur*ery as )ell as intubation and ventilation can sti+ulate bronchos-as+. 8s there any history of bein* hos-italiBed intubated or -rescribed steroids for asth+a This can hel- assess the severity of disease. "idney or #i$er disease @ 4ifferent anesthetic dru*s have different +odes of clearance and or*an function can affect our choice of dru*s.
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%eflux Disease @ Present or not AnesthetiBed and relaxed -atients are -rone to re*ur*itation and as-iration -articularly if a history of reflux is -resent. This is usually an indication for ra-id se
Dndocrine? Steroids E -atients )ith recent steroid use +ay re
,hile a history of a difficult intubation +ay be the +ost reliable -redictor of future difficult intubations the -hysical exa+ is also i+-ortant to hel- -redict -otential -roble+s. or the -hysical exa+ the s-ecific areas )hich are of -articular i+-ortance to the anesthesiolo*ist include the cardiovascular syste+ lun*s headFneckFu--er air)ay si*ns of -reexistin* neurolo*ical dysfunction and si*ns of coa*ulation dysfunction. Many tests have been -ro-osed to hel- -redict difficulty )ith intubation but no sin*le factor taken inde-endently has been able to acco+-lish this *oal. Ho)ever )hen
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+ulti-le factors are taken to*ether the -redictive value is increased. The follo)in* so+e s-ecific as-ects of the headFneckFu--er air)ay exa+ )hich can be used to hel- -redict difficulties that +ay be encountered. HeadFIeckFU--er Air)ay exa+ (acial trau!a or defor!ities@ +ay +ake it difficult to -erfor+ laryn*osco-y. De$iated septu! or nasal polyps@ can -ose difficulty )ith nasal intubation or )ith insertin* a naso*astric tube -ossibly resultin* in bleedin*. )eck ran&e of !otion@ the -atient needs to be able to assu+e the sniffin* -osition 5cervical flexion and atlanto@occi-ital extension7 so that the oral -haryn*eal and laryn*eal axes are ali*ned )hich )ill facilitate vie)in* the *lottic o-enin*. Ior+al -atients should achieve 3& de*rees or +ore of atlanto@occi-ital extension )hich can assessed by observin* the an*le traversed by the occlusal surface of the +axillary teeth )hen the head is fully extended fro+ the neutral -osition. 4ifficulty )ith intubation +ay be -redicted by a si*nificant reduction in the ability to achieve this de*ree of extension or if the -atient ex-eriences any -ain tin*lin* or nu+bness durin* this +ove+ent. TM* !o'ility and de&ree of !out openin& @ this is i+-ortant for deter+inin* the ade
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The siBe of the +andible can be assessed by +easurin* the thyro+ental distance. This is the distance fro+ the +entu+ of the +andible to the thyroid cartila*e. A thyro+ental distance of c+ 5a--roxi+ately 3 fin*er breadths7 or less as often seen in -atients )ith a recedin* +andible or a short neck +ay indicate a -ossible difficult intubation. Alternatively the sterno+ental distance 5fro+ +entu+ to sternal notch7 can also be used )hich assesses the siBe of the +andible and neck. A sterno+ental distance of J "3 c+ +ay also -oint to difficulty )ith intubation. inally a -hysical status classification is assi*ned based on the criteria of the A+erican Society of Anesthesiolo*ists 5ASA"@&7 )ith ASA@" bein* assi*ned to a healthy -erson )ithout +edical -roble+s other than the current sur*ical concern and ASA@& bein* a +oribund -atient not ex-ected to survive for +ore than t)enty four hours )ithout sur*ical intervention. An 9D9 is added if the case is e+er*ent. The full details of the classification scale are also detailed later. IV’* $+ P&-4-+',%'#$ The t)o skills you should take the o--ortunity to -ractice )hile on your rotation are 8L insertion and air)ay +ana*e+entFintubation. Dvery -atient 5)ith the exce-tion of so+e children that can have their 8L:s inserted follo)in* inhalation induction7 )ill re
Many -atients are understandably nervous -reo-eratively and )e often -re+edicate the+ usually )ith a ra-id actin* benBodiaBe-ine such as intravenous +idaBola+ 5)hich is also fabulously effective in children orally or rectally7. Metoclo-ra+ide ;icitra andFor an H$ blocker are also often used if there is a concern that the -atient has a full sto+ach and anticholiner*ics such as *lyco-yrrolate can be used to decrease secretions. R##4 S-%) $+ M#$'%#&* ;efore brin*in* the -atient to the roo+ the anesthesia +achine ventilator +onitors and cart +ust be checked and set u-. The anesthesia +achine +ust be tested to ensure that the *au*es and +onitors are functionin* -ro-erly that there are no leaks in the *as delivery syste+ and that the backu- syste+s and fail@safes are functionin* -ro-erly.
The +onitors that )e use on +ost -atients include the -ulse oxi+eter blood -ressure +onitor and electrocardio*ra+ all of )hich are ASA re
Arterial lines for continuous blood -ressure +onitorin* E usually radial but can be brachial fe+oral etc. o
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Used in any case )here )ide s)in*s in blood -ressure are ex-ected )here ti*ht control of blood -ressure is needed in cardio-ul+onary by-ass cases or )hen there )ill be the need for +ulti-le blood *as analyses.
Central venous lines for +easurin* CLP@ ty-ically 8K or subclavian o
Used in any case )hen there is the need to closely +onitor the intravascular volu+e status or there is a need to evaluate ri*ht ventricular function.
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Pul+onary artery catheter for +easurin* ,ed*e -ressure 5LD4P7 o
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Used to deter+ine 2AP PA LD4P C/ and Pv/$. These +easure+ents are hel-ful )hen faced )ith -oor left ventricular function valvular disease recent M8 A24S +assive trau+a +aOor vascular sur*eries or )hen there is a critical need to accurately assess the intravascular fluid volu+e or the res-onse to blood -ressure interventions.
Transeso-ha*eal echo 5TDD7 E used in +any CL cases o
Used to evaluate re*ional )all +otion abnor+alities indicative of +yocardial ische+ia to evaluate stroke volu+eFeOection fraction to evaluate cardiac valvular function to look for intracardiac air to +onitor chan*es in cardiac function or to evaluate ade
The anesthesia cart is set u- to allo) easy access to intubation e
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,hen it co+es to dra)in* u- the initial dru*s there are % cate*ories of dru*s that should be ready for each case? induction a*ents sedationFanal*esia dru*s reversal a*ents and e+er*ency dru*s. At ti+es the s-ecific dru*s +ay vary de-endin* on the case but the follo)in* are +ost co++only used. The first 3 cate*ories should be dra)n u- in -re-aration for the case but the e+er*ency dru*s are often already -re-ared. -nduction A&ents idocaine 5"7 5"#+*F+7 E 4ra) u- in a &cc syrin*e Pro-ofol 5"#+*F+7 E 4ra) u- in a $#cc syrin*e 2ocuroniu+ 5"#+*F+7 E 4ra) u- in a &cc syrin*e Sedation+Anal&esia Dru&s Lersed 5"+*F+7 E 4ra) u- in 3cc syrin*e entanyl 5&#+c*F+7 E 4ra) u- in &cc syrin*e %e$ersal A&ents
Ieosti*+ine 5"+*F+7 E 4ra) u- in &cc syrin*e lyco-yrrolate 5#.$+*F+7 E 4ra) u- in &cc syrin*e .!er&ency Dru&s 5QAt Her+ann these dru*s are already -re-ared and should be found in -lastic ba*7
QPhenyle-hrine 5"##+c*F+7 E 8n "#cc syrin*e QD-hedrine 5&+*F+7 E 8n "#cc syrin*e QSuccinylcholine 5$#+*F+7 E 8n "#cc syrin*e Atro-ine "+*F+ E 8n 3cc syrin*e /ther -re-arations that can be done before the case focus on -atient -ositionin* and co+fort since anesthesiolo*ists ulti+ately are res-onsible for intrao-erative -ositionin* and resultant neurolo*ic or skin inOuries. Heel and ulnar -rotectors should be available as should axillary rolls and other -ads de-endin* on the -osition of the -atient.
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I$+),%'#$ $+ I$%)(%'#$ Nou no) have your sedated -atient in the roo+ )ith his 8L 5*ender selected at rando+ ... you *enerally anesthetiBe +en and )o+en the sa+e7 and he:s co+fortably lyin* on the o-eratin* table )ith all of the afore+entioned +onitors in -lace and functionin*. 8t is no) ti+e to sto) your tray tables and brin* your seats to the full u-ri*ht -osition because it:s ti+e for take@off. 8ndeed +any -eo-le co+-are anesthesia )ith flyin* an aircraft since the take@off and landin* can be
The first -art of induction of anesthesia should be -re@oxy*enation )ith "## oxy*en delivered via a face +ask. The *oal should be an end@tidal oxy*en concentration of +ore than '# a Sa#$ of "## or lackin* end tidal *as +onitorin* at least four full tidal volu+e breaths )ith a ti*ht fittin* +ask. Perfor+in* a 0Oa) thrust1 or 0chin lift1 )ill o-ti+iBe the -atient’s air)ay for ba* +ask ventilation.
The reason )e -re@oxy*enate -rior to induction and intubation is to +axi+iBe the a+ount of ti+e a -erson can tolerate a-nea )ithout desaturatin*. This translates to +ore ti+e available to secure the air)ay )hich is very i+-ortant if the -atient turns out to have an unantici-ated difficult air)ay. ,hen breathin* sto-s the body’s oxy*en stores are li+ited to the oxy*en in the blood and the oxy*en in the lun*s. A nor+al -erson uses a--roxi+ately $&#@3## + of oxy*en each +inute and can desaturate in as little as 3# E # seconds of a-nea. ,ithin the lun*s the functional residual ca-acity 52C7 is a--roxi+ately 3 liters in a nor+al -erson. ,hen breathin* roo+ air 5$" /$7 the 2C contains +ostly nitro*en and a relatively s+all a+ount of oxy*en. Ho)ever )hen breathin* "## /$ this effectively re-laces the nitro*en )ith oxy*en )ithin the 2C and creates a tre+endous additional reserve of oxy*en that can be used by the body. This -re@ oxy*enation can -rovide 3 E additional +inutes of a-nea before si*nificant /$ desaturation occurs. A*ain usin* the exa+-le of a nor+al s+ooth induction in a healthy -atient )ith an e+-ty sto+ach the next ste- is to ad+inister an 8L anesthetic until the -atient is unconscious. A useful *uide to anesthetic induction is the loss of the lash reflex )hich can be elicited by *ently brushin* the eyelashes and lookin* for eyelid +otion. Patients fre
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relaxer7 or vecuroniu+ 5or any of the other @oniu+s or @uriu+s )hich are all non de-olariBin* relaxers7. A t)itch +onitor is usually used to ascertain de-th of relaxation and )hen the t)itch has sufficiently di+inished intubation can be atte+-ted. Iote that the above induction a*ents usually last for less than ten +inutes so +any of us )ill turn on a volatile anesthetic a*ent )hile )e are +ask ventilatin* and )aitin* for the +uscle relaxant to take effect. Try to kee- a *ood +ask seal so you don:t anesthetiBe yourself ... /nce the -atient is ade
M'$%-$$,As )ith flyin* an air-lane the +aintenance -ortion of anesthesia can be very s+ooth but )hen thin*s *o )ron* they can *o very )ron* very
8t is also vital to -ay attention to the case itself since blood loss can occur very ra-idly and certain -arts of the -rocedure can threaten the -atient:s air)ay es-ecially durin* oral sur*ery or DIT cases. 8t is also i+-ortant to kee- track of the -ro*ress of the case. 8t is a co++on be*inner:s +istake to *ive -atients a +uscle relaxant that lasts for an hour )hen the case only has "# +inutes to *o. A *ood anesthesiolo*ist has a 9sixth sense.9 He or she
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is al)ays -ayin* attention to the tone of the -ulse oxi+eter or the slur-in* of blood into the suction canister. Li*ilance is key to a *ood anesthetic. /ne can also -re-are for -otential -ost@o-erative -roble+s durin* the case by treatin* the -atient intrao-eratively )ith lon*@actin* anti@e+etics and -ain +edications. E4-&5-$,Usin* our analo*y of flyin* an air-lane a -oor landin*Fe+er*ence can be disastrous. =no)in* )hen to turn do)nF off your anesthetic a*ents co+es )ith ex-erience and attention to the -ro*ress of the sur*ical case. D+er*ence isn:t as easy as it +i*ht at first see+ since very i+-ortant ste-s have to take -lace before a -atient can be safely extubated.
,hen usin* nonde-olariBin* neuro+uscular blockin* a*ents such as 2ocuroniu+ or Cisatracuriu+ a -eri-heral nerve sti+ulator is used to +onitor the -har+acolo*ical effects of these dru*s and the dosa*e can be titrated to effect. Iear the end of the case the nerve sti+ulator is used to assess the de*ree of s-ontaneous recovery fro+ these dru*s. Ieosti*+ine an anticholinesterase dru* is ty-ically used as a reversal a*ent )hen the s-ontaneous recovery is occurrin* as deter+ined by the -resence of t)itches induced by the nerve sti+ulator. ,hen utiliBin* a train@of@four sti+ulation the *reater the nu+ber of visible +uscle t)itches the *reater the de*ree of s-ontaneous recovery that has occurred. A lack of +uscle t)itches indicates the blockade at the neuro+uscular Ounction is still too intense and the ad+inistration of neosti*+ine is not likely to facilitate reversal. 8t is also i+-ortant to note that even )ith % t)itches and the return of s-ontaneous breathin* the -atient +ay still have u- to (& of the IMK rece-tors occu-ied by the blockin* a*ent. The ade
RR > 8 & < 30/min
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TV > 5 cc/kg
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TV/RR > 10
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PaO2 > 65-70 mmHg on FiO2 < 40%
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PaO2 < 50 mmHg
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H!mo"#namic $ai'i#
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T!m(!)a*)! a '!a$ 35
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+,F > -20
Suction +ust al)ays be close at hand since +any -atients can beco+e nauseous after extubation or si+-ly have co-ious oro-haryn*eal secretions. /nce the -atient is
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reversed a)ake suctioned and extubated care +ust be taken in transferrin* hi+ to the *urney and oxy*en +ust be readily available for trans-ortation to the recovery roo+FPost@Anesthesia Care Unit 5PACU7. inally re+e+ber that )henever extubatin* a -atient you +ust be fully -re-ared to reintubate if necessary )hich +eans havin* dru*s and e
/ther concerns include continuin* a)areness of the -atient:s air)ay and level of consciousness as )ell as follo)@u- of intrao-erative -rocedures such as central line -lace+ent and -osto-erative @rays to rule out -neu+othorax. 8n su++ary anesthesia is a s-ecialty in )hich an extensive kno)led*e of -hysiolo*y and -har+acolo*y can be a--lied to the care of -atients in a uni
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Co++only Used Medications V#%'- A$-*%-%',* • All are 'roncodilators, except for desflurane /ic is irritatin& and !ay cause 'roncospas!0 Ad!inistered alone 1i0e0, /itout narcotics2, inaled anestetics increase respiratory rate 'ut decrease tidal $olu!e0 • .xcept for alotane, inaled anestetics are not !eta'olied 'y te 'ody and are eli!inated 'y $entilation0 • All $olatile anestetics 1'ut not nitrous oxide2 are capa'le of tri&&erin& !ali&nant yperter!ia 1MH20 • Wile in !any cases $olatile anestetics are used for !aintenance of anestesia, in so!e circu!stances tese dru&s !ay 'e cosen to induce anestesia suc as in pediatrics cases in /ic te cild !ay not tolerate - place!ent a/ake0
Halotane Pro? Chea- nonirritatin* so can be used for inhalation induction Con? on* ti+e to onsetFoffset Si*nificant Myocardial 4e-ression SensitiBes +yocardiu+ to catechola+ines Association )ith He-atitis -soflurane Pro? Chea- excellent renal he-atic coronary and cerebral blood flo) -reservation Con? on* ti+e to onsetFoffset irritatin* so cannot be used for inhalation induction Desflurane Pro? Dxtre+ely ra-id onsetFoffset Con? Dx-ensive Sti+ulates catechola+ine release Possibly increases -osto-erative nausea and vo+itin* 2e
)itrous xide Pro? 4ecreases volatile anesthetic re
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IV A$-*%-%',* • Most sedati$e ypnotics /ork trou& te ini'itory &a!!a5a!ino'utyric acid 1GABA2 neurotrans!itter syste! in /ic increased cloride conductance leads to neuronal ini'ition0 Most - induction a&ents 'ind to a specific site called GABA A for tis ini'itory effect, and tey a$e a rapid onset due to lipopilic properties /ic allo/ te! to 6uickly partition into te i&ly perfused lipopilic 'rain and spinal cord0 Tey also a$e sort duration of action, /it teir ter!ination of effect due to redistri'ution into less perfused tissues suc as !uscle and fat0
Bar'iturates 1e0&0, tiopental2 4ecrease 8CP by decrease in cerebral oxy*en consu+-tion. Since cerebral -erfusion is -reserved desirable dru* for neurosur*ery cases. Causes res-iratory and cardiac de-ression. Pro? Dxcellent brain -rotection Sto-s seiBures CheaCon? Myocardial de-ression Lasodilation Hista+ine release Can -reci-itate -or-hyria in susce-tible -atients 7ropofol 8n adults induction dose ".& to $.& +*Fk* )hile continuous infusion of "## to $## +icro*ra+sFk*F+in +aintains unconsciousness. These values differ for children and for the elderly. Pro? Prevents nauseaFvo+itin* uick recovery if used as solo anesthetic a*ent Con? Pain on inOection Dx-ensive Su--orts bacterial *ro)th Myocardial de-ression 5the +ost of the four7 Lasodilation cross reactivity in -atients )ith e** aller*y. .to!idate Mini+al de-ression of cardiovascular and -ul+onary function. 8deal for -atients )ith CL4 or he+odyna+ic instability. 8nduction dose of #.$ to #.% +*Fk* that causes -ain on inOection and +yoclonus. Su**ested that it +ay su--ress cortisol synthesis. Pro? east +yocardial effect of 8L anesthetics Con? Pain on inOection Adrenal su--ression 5 si*nificance if used only for induction7 Myoclonus IauseaFLo+itin* "eta!ine ,orks via anta*onis+ of the I@+ethyl@4@as-artate rece-tor channel co+-lex. Mini+ally de-resses the cardiores-iratory syste+. 8nduction dose of " to $ +*Fk* in adults. 4irectly sti+ulates SIS and increases ;P and heart rate. 8ncreasin* de+and on the heart and is not a *ood choice for CA4 -atients. Pro? ,orks 8L P/ P2 8M @ *ood choice in uncoo-erative -atient )ithout 8L Sti+ulation of SIS → *ood for hy-ovole+ic trau+a -atients often -reserves air)ay reflexes Con? 4issociative anesthesia )ith -osto- dys-horia and hallucinations 8ncreases 8CPF8/P and CM2#$ Sti+ulation of SIS → bad for -atients )ith co+-ro+ised cardiac function increases air)ay secretions
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Dex!edeto!idine Selective al-ha@$ adrener*ic a*onist )hich is used in the o-eratin* roo+ as an adOunct to *eneral anesthesia or to -rovide sedation for a)ake fibero-tic intubation or for re*ional anesthesia. 8t is *enerally *iven as a loadin* dose of #.&@" +c*Fk* over "# +inutes follo)ed by an infusion of #.$ to #.( +c*Fk*Fhr. 8t -roduces sedative@hy-notic and anal*esic effects )ithout causin* res-iratory de-ression. Benodiaepines 1BD82 Usually -rovided as -re+edication for sedation and anxiolysis before *eneral anesthesia. Pro-erties include anxiolytic effects to sedation and unconsciousness at hi*her doses. MidaBola+ 5Lersed7 induction dose of #." to #.$ +*Fk* and infusion rates of #.$& to " +icro*ra+Fk* -er +inute. ;4Vs -roduce res-iratory cardiovascular and u--er air)ay reflex de-ression and in the -resence of hy-ovole+ia +ay cause si*nificant hy-otension. 2eversal of the sedative action of these co+-ounds )ith the co+-etitive anta*onist flu+aBenil. L#, A$-*%-%',* .sters @ MetaboliBed by -las+a esterases @ one +etabolite is PA;A )hich can cause aller*ic reactions. Patients )ith 9aller*y to novacaine9 usually do )ell )ith a+ides for this reason. All have only one 9i9 in their na+e e*. Procaine Tetracaine Chlor-rocaine.
A!ides @ MetaboliBed by he-atic enBy+es. All have at least t)o 9i9s in their na+e e*. idocaine 2o-ivicaine ;u-ivicaine O'#'+* Morpine E de-resses breathin* -rinci-ally by i+-airin* the +edullary res-onse to C/$. Also tri**er the che+orece-tor tri**er Bone 5CTV7 )hich +ay lead to nausea and +ay in turn sti+ulate the vo+itin* center and -roduce e+esis. Also +or-hine decreases 8 +otility and -ro-ulsion -roduces urinary retention and releases hista+ine by sti+ulatin* baso-hils in the lun*s and +ast cells in the skin. 8n the CLS +or-hine +ay -roduce vascular dilation decrease SL2 and overall hy-otension. 8t is lon* actin* > renally excreted → active +etabolite has o-iate -ro-erties therefore be)are in renal failure
De!erol @ eu-horia sti+ulates catechola+ine release so be)are in -atients usin* MA/8:s renally active +etabolite associated )ith seiBure activity therefore be)are in renal failure
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(entanyl+Alfentanil+Sufentanil+%e!ifentanil @ More -otent than +or-hine )ith Sufentanil bein* the +ost -otent 5u- to "###x as -otent7. 8n addition all are shorter actin* than +or-hine )ith 2e+ifentanil bein* the shortest. /ften used to attenuate the stress res-onse to sur*ical sti+ulation. o) doses -roduce brief effect but lar*er doses are lon* actin* increased incidence of chest )all ri*idity vs. other o-iates no active +etabolites usually safe in -atients )ith +or-hine aller*ies. M)*,- R-7$%* D-#&''$5 Succinylcoline @ inhibits the -ost@Ounctional rece-tor and -assively diffuses off )ith increased 8CPF8/P +uscle fasciculations and -osto+uscle aches tri**ers MH increases seru+ -otassiu+ es-ecially in -atients )ith burns crush inOury s-inal cord inOury +uscular dystro-hy or disuse syndro+es. 2a-id and short actin*. N#$+-#&''$5 Many different kinds all endin* in 0oniu+1 or 0uriu+1. Dach has a different +etabolis+ onset and duration +akin* choice de-end on s-ecific -atient and case. So+e exa+-les? 7ancuroniu! @ Slo) onset lon* duration tachycardia due to va*olytic effect0 Cisatracuriu!@ Slo) onset inter+ediate duration Hoff+an 5nonenBy+atic7 eli+ination so attractive choice in liverFrenal disease. %ocuroniu! @ astest onset of nonde-olariBers +akin* it useful for ra-id se
)eosti&!ine @ shares duration of action )ith *lyco-yrrolate 5see belo)7 .droponiu! @ shares duration of action )ith atro-ine 5see belo)7 7ysosti&!ine @ crosses the ;;; therefore useful for atro-ine overdose A$%',#'$-&5',* iven )ith reversal a*ents to block the +uscarinic effects of choliner*ic sti+ulation also excellent for treatin* bradycardia and excess secretions
"
Atropine @ used in conOunction )ith Ddro-honiu+ crosses the ;;; causin* dro)siness so +aybe bad at end of sur*ery for reversal so+e use as -re+ed for all children since they tend to beco+e bradycardic )ith intubation and -roduce co-ious drool Glycopyrrolate @ used in conOunction )ith neosti*+ine does not cross ;;;
Central Anticholiner*ic Syndro+e? ;lind as a bat 5;lurred vision7 2ed as a beet 5lushin*7 4ry as a bone 5Anhydrosis7 ast as a hare 5Tachycardia7 Mad as a hatter 54eleriu+7
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Phar+ Charts I$%'#$ A$-*%-%',* I$%'#$ A$-*%-%',*
M9#& A+0$%5-*
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Io odor ast induction and recovery Mini+al cardio-ul+onary de-ression ood anal*esic Pleasant odor Slo)er induction and recovery
Minor sur*ery Used in co+bination )ith *eneral anesthetics for *eneral anesthesia
Acute@IFL Chronic@inhibition of ;"$ +etabolis+ and induction of ;"$ 4D8C8DICN
Most )idely used -edi anesthetic )orld )ide. Asth+a -atients 5no bronchoconstriction7
Slo) inductionFrecovery SensitiBes +yocardiu+ to catechola+inesLent. Arryth+ias H e-atotoxicity Hy-otension SeiBures 6 hi*h W X Ie-hrotoxicity Pun*ent odor 5not *reat for kids7 ;roncho@irritant
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Pleasant odor ess S.D. than Halothane
Adults
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Stable cardiac rhyth+ 2a-id onsetFrecovery Mini+al +etabolis+lo) tox -otential Dxcellent Muscle relaxant 2a-id onsetFrecovery Hi*h -otency 5least soluble7 Dven less +etabolis+
Most )idely used anesthetic in adults.
ast inductionFrecovery Hi*h -otency 5least soluble7 Ionirritatin* va-or
/ut-atient anesthesia 8nhalation 8nduction 5es-ecially children7
D-*6)&$-
S-0#6)&$-
A+bulatory sur*ery 5for ra-id recovery7
Lery -un*ent 8rritatin* to air)ays A2NI/SPASM Dx-ensiveYYY
2enal Toxicity
M-%#76)&$-
Iitrous /xide 4esflurane Sevoflurane Dnflurane S-eed of /nset ASTDST
8soflurane Halothane
Potency
/,DST
Hi*h MAC
5"#%7
Methylfurane S/,DST H8HDST o) MAC
57
5$.$7
5".&7
5#.'7
MAC Mini+u+ Alveolar Concentration E defines the a+ount of anesthetic necessary to achieve no res-onse to sur*ical sti+ulus. The nu+bers listed above are the concentrations necessary to achieve " MAC or no res-onse in &# of the -o-ulation. A MAC of ".3 is $ standard deviations u- or )here !& don’t res-ond. A MAC of ".& is the MAC ;A2 )here sy+-athetic outflo) is co+-letely blocked. ,hen usin* +ulti-le a*ents MAC’s are additive i.e. Z MAC of nitrous 5&$7 Z MAC of Sevo 5"."7 is e
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I$%&0-$#)* A$-*%-%',* I$%&0-$#)* A$-*%-%',*
O$*-%
B&('%)%-* 5H>A7 @Thio-ental @Methohexital @Thia+ylal
3#@%# sec
B-$#+'-'$ -* 5H>A7 @4iaBe-a+ @MidaBola+ @oraBe-a+
3@& +in
E'4'$%'#$
P&4,#:'$-%',*
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2a-id onset ast recovery
@"#@"$ hrs @ 3@ hrs
@$#@%# hrs @$@ hrs
4e+ethelated in the iver. 5-rolon*ed t"F$ )ith cirrosis etc7
Io anal*esia AlkalineFTissue 8rritant. Anesthesia for 2es- > CL short de-ression -rocedures. o) T8 /4 risk 2elative ra-id Iot a *ood onset anal*esic Mini+al resCan’t -roduce and CL sur*ical anal*esia de-ression Preanesthetic 8ntense anal*esia and a+nesia
@$@3 hrs
D'**#,'%'05H>A7 @=eta+ine
2adiolo*ical -rocedures in children ;ronchodilato r M'*,-$-#)* 5H>A7 @Dto+idate @Pro-ofol
O'#'+* ;A< @Mor-hine @entanyl @Me-eridine 54e+erol7 @Sufentanyl
[" +in %#@&# sec
%@'hrs 3@hrs
$@( hrs 3@% hrs $@% hrs
ar*e volu+e of distribution hi*hly li-o-hilic
D'*+0$%5-*
Prevents IFL
Mini+al CL effects at nor+al dosa*es
4issociative anesthesia 5887 un-leasant recovery )F hallucinations and ni*ht+ares
Hy-otension cv de-ression re
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8L luids H#= M),> Ty-e \ H2 " Maintenance -er hour " 5% $ " rule or k* %# in anyone over $# k*7 4eficit "F$ 5Hrs IP/ x Maintenance7 8nsensible oss 53@"& ccFhr ? case de-endent7 Dsti+ated blood loss 5"?" colloid 3?" crystalloid7
$ "
3 "
"F% "F%
% " @
A#=(- B##+ L#** The allo)able loss is calculated by +ulti-lyin* the blood volu+e 5;L7 by the -ercent fro+ startin* he+atocrit 5HCTs7 to threshold he+atocrit 5HCTt7 for transfusion.
A; ] ;L x 55HCTs@HCTt7FHCTs7 ;lood volu+e is deter+ined by +ulti-lyin* the )ei*ht by a constant. Ieonates ] !# ccFk* 8nfants ] '# ccFk* Adult +en ] # ccFk* Adult )o+en ] &# ccFk* E74A &# k* )o+an co+es in after fastin* for "$ hours for elective sur*ery. Her -re@ohe+atocrit )as 3&. Nou decide that in order to transfuse she +ust have a he+atocrit less than $&. /ver the course of the sur*ery she loses $&# cc’s of blood each hour for 3 hours. She has only +ini+al blood loss durin* the last hour of her % hour sur*ery. Ty-e \ H2 " $ 3 % Maintenance -er hour !# !# !# !# 5% $ " rule /2 k* %# in anyone over $# k*7 4eficit &%# $(# $(# @ 5Hrs IP/ x Maintenance7 "$ x !# ] "#'# 8nsensible oss ' ' ' ' 53@"& ccFhr ? case de-endent7 Dsti+ated blood loss Col E $&# Col E $&# Col E $&# @ 5"?" colloid 3?" crystalloid7 C&*? @ C&*? @ C&*? @ Total crystalloid "3'' """# """# !' Additionally she should be transfused as she -assed her threshold for transfusion durin* the third hour. Since that -oint )as close to the end of sur*ery transfusion -robably could be held off until arrival at PACU since transfusion reaction is not easily noticed )hile under *eneral anesthesia.
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ASA Classification The -ur-ose of the *radin* syste+ is si+-ly to assess the de*ree of a -atient’s 9sickness9 or 9-hysical state9 -rior to selectin* the anesthetic or -rior to -erfor+in* sur*ery. 4escribin* -atients’ -reo-erative -hysical status is used for recordkee-in* for co++unicatin* bet)een collea*ues and to create a unifor+ syste+ for statistical analysis. The *radin* syste+ is not intended for use as a +easure to -redict o-erative risk. The +odern classification syste+ consists of six cate*ories as described belo).
ASA P*', S%%)* ;PS< C**'6',%'#$ S*%-4 ASA PS C%-5#&
P&-#-&%'0- H-% S%%)*
C#44-$%* E74-*
ASA PS "
Ior+al healthy -atient
Io or*anic -hysiolo*ic or -sychiatric disturbance^ excludes the very youn* and very old^ healthy )ith *ood exercise tolerance
ASA PS $
Patients )ith +ild syste+ic Io functional li+itations^ disease has a )ell@controlled disease of one body syste+^ controlled hy-ertension or diabetes )ithout syste+ic effects ci*arette s+okin* )ithout chronic obstructive -ul+onary disease 5C/P47^ +ild obesity -re*nancy
ASA PS 3
Patients )ith severe syste+ic disease
So+e functional li+itation^ has a controlled disease of +ore than one body syste+ or one +aOor syste+^ no i++ediate dan*er of death^ controlled con*estive heart failure 5CH7 stable an*ina old heart attack -oorly controlled hy-ertension +orbid obesity chronic renal
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failure^ bronchos-astic disease )ith inter+ittent sy+-to+s ASA PS %
Patients )ith severe syste+ic disease that is a constant threat to life
Has at least one severe disease that is -oorly controlled or at end sta*e^ -ossible risk of death^ unstable an*ina sy+-to+atic C/P4 sy+-to+atic CH he-atorenal failure
ASA PS &
Moribund -atients )ho are Iot ex-ected to survive not ex-ected to survive $% hours )ithout sur*ery^ )ithout the o-eration i++inent risk of death^ +ultior*an failure se-sis syndro+e )ith he+odyna+ic instability hy-other+ia -oorly controlled coa*ulo-athy
ASA PS
A declared brain@dead -atient )ho or*ans are bein* re+oved for donor -ur-oses ASA PS ,**'6',%'#$* 6 %- A4-&',$ S#,'-% #6 A$-*%-*'##5'*%*
Malla+-ati Classification The Malla+-ati Classification is based on the structures visualiBed )ith +axi+al +outh o-enin* and ton*ue -rotrusion in the sittin* -osition 5ori*inally described )ithout -honation but others have su**ested +ini+u+ Malla+-ati Classification )ith or )ithout -honation best correlates )ith intubation difficulty7. Class 8? soft -alate fauces uvula -illars Class 88? soft -alate fauces -ortion of uvula Class 888? soft -alate base of uvula Class 8L? hard -alate only
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uick 2eferenceF2evie) •
Pre@Anesthesia Dvaluation Cardiac Patient E decreased exercise tolerance i+-ortant si*n^ if able to o cli+b $ fli*hts of stairs cardiac reserve -robably intact Post@M8 E infarction risk stabiliBes at &@ after +onths Perio-erative M8 +ortality $#@&# • 8f no -rior M8 -erio-erative risk #."3 • /ccur in %'@($ hrs -ost@o• • Io elective sur*ery )ithin +onths of M8 Prior Cardiac Sur*ery or PTCA is not contraindication to sur*ery Contraindication to sur*ery ] M8 J" +onth unco+-ensated CH severe AS or MS Dvaluation MaOor risk E unstable coronary syndro+e • 8nter+ediate risk E +ild an*ina -rior M8 CH 4M • Minor risk E a*e abnor+al D= arrhyth+ia decreased • functional ca-acity stroke uncontrolled HTI Studies E D= Holter stress test technetiu+ !!+ thalliu+ i+a*in* coronary an*io*ra-hy C/P4 o Dx-lain obstruction 4eter+ine severity and res-onsiveness to albuterol *et PT’s C2 if hi*hly sy+-to+atic 8ncreased risk if -re@o- PT’s J&# -redicted Also hel-ful to deter+ine ho+e /$ re
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•
•
Mali*nant Hy-erther+ia E skeletal +uscle hy-er+etabolic syndro+e Tri**erin* anesthetics E halothane esflurane isoflurane desflurane o sevflurane succinylcholine ene E Ca channel of skeletal +uscle sarco-las+ic reticulu+ )ith o decreased reu-take of Ca Sy+-to+s E increased H2 increased breath rate increased etC/$ 5+ost o sensitive7 unstable ;P cyanosis coca@cola colored urine ate si*ns 5@$% hrs7 E increased te+-erature +uscle s)ellin* heart failure 48C liver failure Confir+ dia*nosis by lar*e difference bet)een venous C/$ and arterial o C/$ abs E 2es-iratory and +etabolic acidosis hy-oxia hy-erkale+ia o hy-ercalce+ia hi*h +yo*lobin hi*h CP= +yo*lobinuria o 8ncidence E "?$$####^ "?%#### )ith succinylcholine o Mortality E "# overall (# )ithout dantrolene o uture anesthesia E no -retreat+ent )ith dantrolene flush anesthesia +achine T o " @ Call for hel$ @ Sto- volatile anesthetic 3 E "## /$ % E Manually hy-erventilate & E S)itch to a clean breathin* circuit E Sto- sur*ery +aintain on sedative@hy-notic anesthesia ( E 4antrolene $.&+*Fk* 5+ixed )ith sterile )ater7 < "# +inutes to +ax dose of "#+*Fk*. Maintenance dose at "+*Fk* < hrs for ($ hours. ' E Correct +etabolic acidosis )ith IaCH/3 "@$+*Fk* Correct hi*h = ! E Cool -atient )ith iced 8L IS and cold fluids in *astric lava*e in -eritoneal or thoracic cavity if o-en and P2 "# E Maintain urine out-ut )ith +annitol or lasix. 4o not use CC;’ 8L luids 52 IS7 o Maintenance 5%$"7 IP/ ti+e 5Maintenance Q G hrs7 Dva-orative o loss 5"@'ccFk*Fhr7 ocal Anesthetics Dsters E 1 0i1 in na+e 5i.e. novocaine7 +etaboliBed by -las+a o -seudocholinesterases. /ne of its +etabolites is PA;A )hich causes aller*ic reactions 5i.e. )ith Procaine and Tetracaine7. CS has no esterases. Sulfa aller*ic -atients. A+ides E 2 0i1s in na+e 5ie. idocaine ;u-ivicaine7 +etaboliBed by o liver enBy+es +ay cause +ethe+e*lobine+ia 5-rilocaine bu-ivicaine7 aller*ic reaction rare so+e bad hy-eractivity reactions
%$ Mechanis+ E decrease -er+eability to Ia ions binds to Ia channel in inactivated state no threshold -otential reached affects ra-id firin* nerves first +yelinated un+yelinated o Contraindications E hy-ersensitivity severe heart block ,P, syndro+e o Toxicity E often follo)s -redictable -attern of tinnitus -erioral nu+bness and tin*lin* sense of doo+ seiBure co+a. Cardio E decreased -hase 8L de-olariBation increased P2 )ide 2S Pul+onary E -hrenicFintercostal nerve -aralysis CIS E diBBiness circu+oral nu+bness tinnitus blurred vision excitatory si*ns CIS de-ression Muscle E toxic inOected 8M idocaine kno)n to decrease coa*ulation Air)ay Mana*e+ent MA E sub for DT tube as lon* as inflation^ +ay be used as *uide for o intubation Pro-ofol used for induction E relaxes Oa) =ee- in -lace until -atient o-ens +outh on arousal Co+-lications E as-iration +ucosa inOury laryn*os-as+Fcou*hin* Contraindication E risks for *astric as-iration such as D24 -re*nancy recent +eal Mendelssohn’s Syndro+e As-iration -neu+onia secondary to as-iration of *astric contents o T E su--ortive ad+ission to 8CU continued intubation res-iratory o thera-y suctionin* /$ no antibiotics
•
•
•
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&. Pass tube E i++ediately follo)in* fasiculations fro+ succinylcholine . Post@tube +ana*e+ent E ta-e tube o-ioids etc etc.
•
•
Dxtubation Criteria o Tidal volu+e &ccFk* o 2es-irations s-ontaneous and 'F+in o I8 of @"# to @"& Patient sho)in* -ur-oseful +ove+ent o Te+-erature of 3& C or *reater o He+odyna+ic stability o Pa/$ _ # on i/$ %# Pco$ ` && ++H* o aryn*os-as+ Children at es-ecially hi*h risk o Try to break first by *ivin* hi*h -ositive -ressure o 8f cannot break +ust use succinylcholine to -aralyBe -atient to ba*@+ask o or re@intubate.
Pre@o- 2oo+ Pre- Checklist Machine E +achine checkout /$ calibration *as level Suction Monitors E A line central line Pulse /x ;P D= ;8S Air)ay E laryn*osco-e oral air)ay +ask tube / Te+- -robe IL E alcohol needle flush on he-lock ta-e 8L Dru*s E -ro-ofol eto+idate -aralytic narcotic versed -henytoin atro-ine e-ine-hrine succinylcholine S -ecial Seat Labs E ty-e and cross H>H coa*s
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Procedure Checklist The -ur-ose of this section is to -rovide you )ith a list of -rocedures you +ay be re
IV '$- ,-4-
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2esources The follo)in* are a short list of additional resources that you +i*ht find hel-ful durin* your anesthesia +onth in findin* +ore in de-th details about anesthesia. T-7%
Mor*an D Mikail MS Murray MK. 0Clinical Anesthesiolo*y1 Mcra) Hill Medical. $##& 5Y(&7 lidden 2S. 0IMS Anesthesiolo*y1. i--incott ,illia+s > ,ilkins. $##3. 5Y$#7 W-(
Lirtual Anesthesia Text ;ook htt-?FF))).virtual@[email protected]+Findex.sht+l ,orld Anaesthesia /nline htt-?FF))).nda.ox.ac.ukF)fsaFindex.ht+
3#
Iotes
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