Anaesthesia in Surgery in Obese Patients - Copy

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MANAGEMENT OF ANAESTHESIAMANAGEMENT OF ANAESTHESIAIN AN OBESE PATIENTIN AN OBESE PATIENT

MODERATOR – DR.A.MODERATOR – DR.A.S.BHATTACHARYAS.BHATTACHARYA

ASST. PROFF.ASST. PROFF.PRESENTER – DR. NITA HAZARIKAPRESENTER – DR. NITA HAZARIKA

P.G. STUDT.P.G. STUDT.

DEPT.OF ANAESTHESIOLOGY ANDDEPT.OF ANAESTHESIOLOGY AND

CRITICAL CARE, GMCHCRITICAL CARE, GMCH

DATED : 08-11-08DATED : 08-11-08



INTRODUCTIONINTRODUCTION

While undernutrition and malnutrition areWhile undernutrition and malnutrition areproblems of the developing country ,problems of the developing country ,

obesity is the bane of the developedobesity is the bane of the developed

country.Modern lifestyles and bettercountry.Modern lifestyles and better

standards of living have in a way beenstandards of living have in a way beencontributory in making obesity a globalcontributory in making obesity a global

health problem whose prevalance ishealth problem whose prevalance is

increasing day by day.increasing day by day.

Data shows that in UK , 22.9% of menData shows that in UK , 22.9% of men

and 25.4% of women are obese.In US theand 25.4% of women are obese.In US the

prevalance ranges from 33 – 36%.India isprevalance ranges from 33 – 36%.India is



PATHOPHYSIOLOGYPATHOPHYSIOLOGYIn simple terms , obesity is a condition of In simple terms , obesity is a condition of

excessive body fat.The term is derivedexcessive body fat.The term is derived

from the Latin wordfrom the Latin word obesusobesus which meanswhich means

“fattened by eating”.“fattened by eating”.



When the net energy intake is in excessWhen the net energy intake is in excess

of the net energy expenditure over aof the net energy expenditure over a

prolonged period of time , the excessprolonged period of time , the excessenergy gets laid down in various parts of energy gets laid down in various parts of

the body as fat.the body as fat.



Our brain controls appetite byOur brain controls appetite by

means of signals triggered by dietarymeans of signals triggered by dietary

breakdown products and bybreakdown products and by

autonomic signals produced byautonomic signals produced by

disturbance of the stomach and thedisturbance of the stomach and the

intestine.Multiple signals areintestine.Multiple signals aregenerated and processed bygenerated and processed by

interactions between neuronalinteractions between neuronal

networks and neurotransmittersnetworks and neurotransmitters,most important being CCK8,which,most important being CCK8,which

acts at gut and the brain.It inducesacts at gut and the brain.It induces

satiation ,is released at the beginningsatiation ,is released at the beginningm l n r l in lin . n linof a meal and releases insulin .Insulin



DISTRIBUTION OF FAT AND OBESITYDISTRIBUTION OF FAT AND OBESITY

INDUCED MORBIDITYINDUCED MORBIDITY Fat in the various parts of the body hasFat in the various parts of the body has

different metabolic effects and isdifferent metabolic effects and is

associated with different morbidity.Fatassociated with different morbidity.Fat

distributed primarily on the buttocks anddistributed primarily on the buttocks andthighs (gynaecoid) is metabolicallythighs (gynaecoid) is metabolically

relatively inert and is not associated withrelatively inert and is not associated with

excess morbidity.While fat in a primarilyexcess morbidity.While fat in a primarily

truncal distribution (android, with a waist :truncal distribution (android, with a waist :

hip circumference ratio of 1 in men or 0.8hip circumference ratio of 1 in men or 0.8

in women) is associated with a higherin women) is associated with a higher

oxygen consumption and a higheroxygen consumption and a higherincidence of morbidities.incidence of morbidities.



AETIOLOGY OF OBESITYAETIOLOGY OF OBESITY

Etiology of obesity is complex andEtiology of obesity is complex and

multifactorial.The following have beenmultifactorial.The following have been

implicated-implicated-

.. Genetic predisposition- obesity is foundGenetic predisposition- obesity is found

in Prader Willi syndrome,Laurence- Moonin Prader Willi syndrome,Laurence- Moon

-Biedle syndrome,Ahlstron,Cohen and-Biedle syndrome,Ahlstron,Cohen and

Carpenter syndrome .Carpenter syndrome . .. Medical disorders – cushingMedical disorders – cushing''s synd ,s synd ,

hypothyroidim,insulinoma,craniopharyngiohypothyroidim,insulinoma,craniopharyngio

mama



and other disorders involving theand other disorders involving thehypothalamus.hypothalamus.

.. Drugs – corticosteroids , antidepressants ,Drugs – corticosteroids , antidepressants ,antihistaminics etc.antihistaminics etc.

.. Energy imbalance between intake andEnergy imbalance between intake and

expenditure.expenditure. .. Psychosocial factorsPsychosocial factors

.. Ethnic influences – Africans , Asians ,andEthnic influences – Africans , Asians ,and

Mexicans with central distribution of fatMexicans with central distribution of fatare at higher riskare at higher risk

.. Socioeconomic factors – obesity is seenSocioeconomic factors – obesity is seenmore in poor strata in developed worldmore in poor strata in developed world

and in rich in developing world.and in rich in developing world.



SOME DEFINITIONSSOME DEFINITIONS

OVERWEIGHTOVERWEIGHT : Excess of total body: Excess of total body

weight including all componentsweight including all components

( muscle,bone,water and fat )( muscle,bone,water and fat )

OBESITYOBESITY : Metabolic disease in which: Metabolic disease in which

adipose tissue comprises a greater thanadipose tissue comprises a greater than

normal proportion of body tissue andnormal proportion of body tissue andamount of fat tissue is increased beyond aamount of fat tissue is increased beyond a

point compatible with physical and mentalpoint compatible with physical and mental

health and normal life expectancyhealth and normal life expectancy



METABOLICMETABOLIC SYNDROMESYNDROME : The triad of : The triad of

obesity , hypertension and typeobesity , hypertension and type diabetesdiabetesװװ

mallitus is known as metabolic syndromemallitus is known as metabolic syndrome



MEASUREMENT OF OBESITYMEASUREMENT OF OBESITY

Accurate measurement of body fatAccurate measurement of body fat

content is difficult as it requirescontent is difficult as it requires

sophisticated techniques such as CT scansophisticated techniques such as CT scan

or MRI and electrical impedence studiesor MRI and electrical impedence studies

etc.etc.In our clinical practice ,the variousIn our clinical practice ,the various

approaches that we use to quantifyapproaches that we use to quantify

obesity includes –obesity includes –

. Anthropometry ( skin fold thickness ). Anthropometry ( skin fold thickness )

. Densiometry ( underwater weighing ). Densiometry ( underwater weighing )

. Body Mass Index (BMI ). Body Mass Index (BMI )

. Ideal body weight. Ideal body weight



IDEAL BODY WEIGHTIDEAL BODY WEIGHT

Ideal body weight (in kg) = height in cm –Ideal body weight (in kg) = height in cm –

xx

where x = 100 for adult males and itswhere x = 100 for adult males and its

105 for adult females105 for adult females

a person is said to be obese when his ora person is said to be obese when his or

her actual body weight exceeds ideal bodyher actual body weight exceeds ideal bodyweight by more than 20%weight by more than 20%



RELATIVE WEIGHTRELATIVE WEIGHT

it is the ratio of the actual and ideal bodyit is the ratio of the actual and ideal body

weightweight

BODY MASS INDEXBODY MASS INDEX

.. Most commonly used indexMost commonly used index .. Also known as Quetlet indexAlso known as Quetlet index

BMI = Body wt (in kg)/height (mBMI = Body wt (in kg)/height (m²)²)



CLASSIFICATION OF OBESITY ONCLASSIFICATION OF OBESITY ON

BMI BASISBMI BASIS

BMI CAT. BMIBMI CAT. BMI

Normal 20 –Normal 20 –2525

Overweight 25 –Overweight 25 –

3030Obese 30 –Obese 30 –

3535

Morbidly obese 35 –Morbidly obese 35 –



CLASSIFICATION OF OBESITYCLASSIFICATION OF OBESITY

AND HEALTH RISKAND HEALTH RISK

BMI (kg/m²) HEALTH RISKBMI (kg/m²) HEALTH RISK

Normal 18.5 – 24.9Normal 18.5 – 24.9AverageAverage

Overweight 25.0 – 29.9Overweight 25.0 – 29.9

IncreasedIncreased

Obesity class I 30.0 – 34.9Obesity class I 30.0 – 34.9

ModerateModerate

Obesity class II 35.0 – 39.9Obesity class II 35.0 – 39.9



PHYSIOLOGICAL CHANGESPHYSIOLOGICAL CHANGESASSOCIATED WITH OBESITYASSOCIATED WITH OBESITY

A.CARDIOVASCULARA.CARDIOVASCULAR SYSTEMSYSTEM The cardiac pathology arises from The cardiac pathology arises from

adaptation to excess body mass andadaptation to excess body mass andincreased metabolic demands along withincreased metabolic demands along withfatty infiltration of the heart.fatty infiltration of the heart.

INCREASEDINCREASED BLOODBLOOD VOLUMEVOLUME :Each:Eachkilogram of fat contains 3000 meters of kilogram of fat contains 3000 meters of blood vessels.increased activity of theblood vessels.increased activity of therenin – angiotensin system also plays arenin – angiotensin system also plays a

role in intravascular volume expansionrole in intravascular volume expansion



volume on weight basis is less than normalvolume on weight basis is less than normal

( may reach 45ml/kg compared to 70ml/kg( may reach 45ml/kg compared to 70ml/kg

in normal adults )in normal adults )

LEFTLEFT VENTRICULARVENTRICULAR LOADLOAD : It is increased: It is increased

because of intravascular volume andbecause of intravascular volume and

excess adipose tissue and muscleexcess adipose tissue and muscle

tissue.This leads to an increase in stroketissue.This leads to an increase in stroke

volume and cardiac work leading tovolume and cardiac work leading to

further increase in left ventricularfurther increase in left ventricularload,dilatation and compensatory leftload,dilatation and compensatory left

ventricular hypertrophy which in turnventricular hypertrophy which in turn

decreases left ventricular compliance anddecreases left ventricular compliance and

increases left ventricular filling pressureincreases left ventricular filling pressure



RIGHTRIGHT VENTRICULARVENTRICULAR LOADLOAD : Right: Rightventricular filling pressure increasesventricular filling pressure increases

.Increase in pulmonary artery pressure.Increase in pulmonary artery pressuredue to left ventricular failure anddue to left ventricular failure andpulmonary vasoconstriction may lead topulmonary vasoconstriction may lead toright ventricular hypertrophy andright ventricular hypertrophy and

dilatation.dilatation.

SYSTEMICSYSTEMIC HYPERTENSIONHYPERTENSION : Mild to: Mild tomoderate systemic hypertension ismoderate systemic hypertension is

present in 50 – 60% of obese patientspresent in 50 – 60% of obese patientswhile severe hypertension is present in 5 –while severe hypertension is present in 5 –10%.the causes are-10%.the causes are-

- increased intravascular volume- increased intravascular volume

- increased cardiac output- increased cardiac output



-- hyperinsulinemia leading to activation of hyperinsulinemia leading to activation of

sympathetic nervous system and causingsympathetic nervous system and causingsod.retentionsod.retention

PULMONARYPULMONARY HYPERTENTIONHYPERTENTION : It is: It is

common in obese patients and is due to –common in obese patients and is due to –

- pulmonary vasoconstriction caused by- pulmonary vasoconstriction caused by

hypoxemia , hypercarbia or bothhypoxemia , hypercarbia or both

- left ventricular myocardial dysfunction- left ventricular myocardial dysfunctionwith increased left ventricular fillingwith increased left ventricular filling

pressurepressure

- increased pulmonary blood volume- increased pulmonary blood volume



-- polycythemia secondary to hypoxemiapolycythemia secondary to hypoxemia

causing further increase in intravascularcausing further increase in intravascular

volume.volume.

ISCHAEMICISCHAEMIC HEARTHEART DISEASEDISEASE : obesity is an: obesity is an

independent risk factor for theindependent risk factor for thedevelopment of ischaemic heart diseasedevelopment of ischaemic heart disease

and is more common in obese individualsand is more common in obese individuals

with central distribution of fat .Otherwith central distribution of fat .Other

factors such as systemic hypertensionfactors such as systemic hypertension,diabetes mallitus and,diabetes mallitus and

hypercholesterolemia which are commonhypercholesterolemia which are common

in obese individuals compound the likelyin obese individuals compound the likely

development of ischaemic heart disease.development of ischaemic heart disease.



CARDIACCARDIAC ARRYTHMIASARRYTHMIAS : Frequent in: Frequent inobese and can lead to suddenobese and can lead to sudden

death.The causes are multifactorial –death.The causes are multifactorial – .. Myocardial hypertrophy andMyocardial hypertrophy and

hypoxemiahypoxemia

.. Coronary artery diseaseCoronary artery disease.. Increased plasma catecholamineIncreased plasma catecholamine

concentrationconcentration

.. Fatty infiltration of pacing andFatty infiltration of pacing andconduction systemconduction system

.. Sleep apnoea syndromeSleep apnoea syndrome

..

Hypokalemia due to diuretic useHypokalemia due to diuretic use



Blood vol Metabolicdemand

CO

SV

LV distention

Eccentric LVH

LV systolic & diastolicdysfunction

LVF



B.RESPIRATORY SYSTEMB.RESPIRATORY SYSTEM

LUNG VOLUMES :LUNG VOLUMES :

Obesity imposes a restrictive ventilationObesity imposes a restrictive ventilation

defect because of the weight added to thedefect because of the weight added to the

thoracic cage and the abdominal weightthoracic cage and the abdominal weightimpeding motion of theimpeding motion of the

diaphragm,specially with the assumptiondiaphragm,specially with the assumption

of the supine position.This results inof the supine position.This results in

decreased functional residual capacitydecreased functional residual capacity(FRC ),expiratory reserve volume(FRC ),expiratory reserve volume

(ERV),vital capacity (VC) and total lung(ERV),vital capacity (VC) and total lung

capacity (TLC) with the FRC decliningcapacity (TLC) with the FRC declining

exponentially with increasing BMI.exponentially with increasing BMI.



The FRC may decrease to the point that The FRC may decrease to the point that

small airway closure occurs with resultingsmall airway closure occurs with resulting

ventilation to perfusion mismatching,rightventilation to perfusion mismatching,right

to left shunting,and arterial hypoxemia.to left shunting,and arterial hypoxemia.

Anaesthesia accentuates these changesAnaesthesia accentuates these changes

such that a 50% decrease in FRC occurs insuch that a 50% decrease in FRC occurs inobese anaesthetised patients as comparedobese anaesthetised patients as compared

to a 20% decrease in non obeseto a 20% decrease in non obese

individuals.individuals.





This This decreasedecrease in FRC impairs thein FRC impairs theability of the obese patients to tolerateability of the obese patients to tolerate

periods of apnoea such as during directperiods of apnoea such as during directlaryngoscopy and tracheal intubation.Inlaryngoscopy and tracheal intubation.Infact the obese patients are likely tofact the obese patients are likely toexperience arterial oxygen desaturationexperience arterial oxygen desaturation

following induction of anaesthesia inspitefollowing induction of anaesthesia inspiteof pre-oxygenation reflecting decreaseof pre-oxygenation reflecting decreaseoxygen reservoir and an increased oxygenoxygen reservoir and an increased oxygenconsumption.consumption.

FRC in anaesthetised obese patientsFRC in anaesthetised obese patientscan be increased by-can be increased by-

- ventilation using tidal volumes of 15-- ventilation using tidal volumes of 15-20ml/kg20ml/kg

- large manually performed lung- large manually performed lung



GAS EXCHANGEGAS EXCHANGE

Morbidly obese patients usuallyMorbidly obese patients usuallyhave a modest decrease in arterialhave a modest decrease in arterial

oxygenation and increase in theoxygenation and increase in the

alveolar to arterial oxygen differencealveolar to arterial oxygen difference

due to ventilation to perfusiondue to ventilation to perfusionmismatching.But arterialmismatching.But arterial

oxygenation may deteriorateoxygenation may deteriorate

markedly on induction of anaesthesiamarkedly on induction of anaesthesiaand increased concentration of and increased concentration of

delivered oxygen is required todelivered oxygen is required to

maintain an acceptable PaOmaintain an acceptable PaO22. But the. But the



PULMONARY COMPLIANCE ANDPULMONARY COMPLIANCE ANDRESISTANCERESISTANCE

Pulmonary compliance in morbidlyPulmonary compliance in morbidlyobese patients may be decreased to 35%obese patients may be decreased to 35%of the predicted value.This is due to-of the predicted value.This is due to-

- adiposity in and around the- adiposity in and around the

ribs,diaphragm and abdomenribs,diaphragm and abdomen- smaller lung volumes- smaller lung volumes

- limited movements of the ribs caused- limited movements of the ribs causedby thoracic kyphosis and lumberby thoracic kyphosis and lumber

hyperlordosis from excessive abdominalhyperlordosis from excessive abdominalfat content.fat content.

This decrease in pulmonary compliance This decrease in pulmonary complianceand increase in resistance leads to rapidand increase in resistance leads to rapidand shallowand shallow



breathing ,increased workload on thebreathing ,increased workload on the

respiratory muscles and decreasedrespiratory muscles and decreased

efficiency of breathing.efficiency of breathing.

WORK OF BREATHINGWORK OF BREATHING

Increased metabolic activity in obeseIncreased metabolic activity in obesepatients leads to increase in oxygenpatients leads to increase in oxygen

consumption and carbon dioxideconsumption and carbon dioxide

production .So in order to maintainproduction .So in order to maintain

normocapnia there is increased minutenormocapnia there is increased minute

ventilation which results in increasedventilation which results in increased

oxygen cost i.e.work of breathing.Obeseoxygen cost i.e.work of breathing.Obese

patients typically breathe rapidly andpatients typically breathe rapidly and



OBSTRUCTIVE SLEEP APNOEAOBSTRUCTIVE SLEEP APNOEA

Obstructive sleep apnoea is a disorderObstructive sleep apnoea is a disorder

in which partial or complete obstructionin which partial or complete obstruction

of the airway during sleep causes loudof the airway during sleep causes loud

snoring ,oxyhaemoglobin desaturation andsnoring ,oxyhaemoglobin desaturation and

frequent arousals.As a result affectedfrequent arousals.As a result affectedpersons have unrestful sleep andpersons have unrestful sleep and

excessive day time sleepiness.Theexcessive day time sleepiness.The

disorder is often associated withdisorder is often associated with

hypertension,impotence and emotionalhypertension,impotence and emotionalproblems.problems.

2% of women and 4% of men over the2% of women and 4% of men over the

age of 50 yrs have symptomaticage of 50 yrs have symptomatic

obstructive sleepobstructive sleep



apnoeaapnoea

PATHOPHYSIOLOGY –PATHOPHYSIOLOGY –

There is peripharyngeal infiltration of There is peripharyngeal infiltration of

fat and /or increased size of the uvula orfat and /or increased size of the uvula or

the soft palate or the tongue in obesethe soft palate or the tongue in obese

patients.Some patients may have apatients.Some patients may have adiminutive or receding jaw that results indiminutive or receding jaw that results in

an insufficient room for the tongue. Thesean insufficient room for the tongue. These

anatomic abnormalities decreases theanatomic abnormalities decreases the

cross sectional area of the uppercross sectional area of the upperairways.Decreased airway muscle toneairways.Decreased airway muscle tone

during sleep and the pull of gravity induring sleep and the pull of gravity in

supine position further decreases airwaysupine position further decreases airway

size thereby impedingsize thereby impeding



airflow during respiraton.airflow during respiraton.

Initially partial obstructionInitially partial obstructionleads to snoring. As tissues collapseleads to snoring. As tissues collapse

further,the airway may becomefurther,the airway may become

completely obstructed,patientcompletely obstructed,patientstruggles to breathe and is arousedstruggles to breathe and is aroused

from sleep. With each arousalfrom sleep. With each arousal

event ,the muscle tone of the tongueevent ,the muscle tone of the tongue

and the airway tissues increase.Thisand the airway tissues increase.This

alleviates the obstruction andalleviates the obstruction and

terminate the apnoeic episode.Soonterminate the apnoeic episode.Soon

the patient falls asleep again and thethe patient falls asleep again and the







MANIFESTATIONSMANIFESTATIONS ––

.. Frequent episodes of obstructiveFrequent episodes of obstructive

apnoea( 10 secs or longer occuring fiveapnoea( 10 secs or longer occuring fivetimes or more per hour during sleep )ortimes or more per hour during sleep )or

hypopnoea (50% decrease in airflow or ahypopnoea (50% decrease in airflow or a

decrease sufficient to lower arterialdecrease sufficient to lower arterial

oxygen saturation by 4%)oxygen saturation by 4%)

.. SnoringSnoring

.. Daytime somnolence most likelyDaytime somnolence most likely

reflecting sleep fragmentation at nightreflecting sleep fragmentation at night(memory and concentration deficits,motor(memory and concentration deficits,motor

vehicle accidents)vehicle accidents)



PHYSIOLOGIC CHANGES –PHYSIOLOGIC CHANGES –

.. Arterial hypoxemiaArterial hypoxemia

.. PolycythemiaPolycythemia

.. HypercarbiaHypercarbia

.. Systemic hypertension (IHD,CVA)Systemic hypertension (IHD,CVA)

.. Pulmonary hypertension (RVF)Pulmonary hypertension (RVF)

RISK FACTORS –RISK FACTORS –

.. Male genderMale gender .. Middle ageMiddle age

.. Obesity (BMI >30)Obesity (BMI >30)



.. Alcohol (evening ingestion)Alcohol (evening ingestion)

.. Drug induced sleepDrug induced sleep



DIAGNOSISDIAGNOSIS ––

It is done by Nocturnal polysomnographyIt is done by Nocturnal polysomnography

in sleep laboratories.in sleep laboratories.

ANAESTHETIC IMPLICATIONS –ANAESTHETIC IMPLICATIONS –

.. These patients are exquisitely sensitive These patients are exquisitely sensitiveto all the CNS depressant drugs.to all the CNS depressant drugs.

.. Difficult tracheal intubationDifficult tracheal intubation

.. Post operative pain management mayPost operative pain management maybe difficult in these patientsbe difficult in these patients



NasalNasal CPAP may allowCPAP may allow

the use of systemicthe use of systemicanalgesics and reduceanalgesics and reduce

the haemodynamicthe haemodynamic

changes.it acts as achanges.it acts as a

Pneumatic splint to holdPneumatic splint to hold

the upper airways openthe upper airways open

during sleep.during sleep.



OBESITY HYPOVENTILATIONOBESITY HYPOVENTILATION

SYNDROMESYNDROME

It is the long term consequence of It is the long term consequence of

obstructive sleep apnoea. There isobstructive sleep apnoea. There is

alterations in the control of breathingalterations in the control of breathing

leading to central apnoeic events (apnoealeading to central apnoeic events (apnoeawithout respiratory effort).This leads towithout respiratory effort).This leads to

progressive desensitisation of respiratoryprogressive desensitisation of respiratory

centers to nocturnal hypercapniacenters to nocturnal hypercapnia

eventually leading to type 2 respiratoryeventually leading to type 2 respiratoryfailure,with increasing reliance on hypoxicfailure,with increasing reliance on hypoxic

drive for ventilation.At its extreme,itdrive for ventilation.At its extreme,it

culminates in the pickwickian syndromeculminates in the pickwickian syndrome

,which is characterised b,which is characterised b



obesity,daytime hypersomnolence,arterialobesity,daytime hypersomnolence,arterial

hypoxemia,polycythemia,hypercarbia,resphypoxemia,polycythemia,hypercarbia,respiratory acidosis,pulmonary hypertensioniratory acidosis,pulmonary hypertension

and right ventricular failure.and right ventricular failure.

ENDOCRINOLOGICAL CHANGESENDOCRINOLOGICAL CHANGES

.. It is an independent risk factor type 2It is an independent risk factor type 2

diabetes.diabetes.

.. Increased cortisol production andIncreased cortisol production andmetabolism is found in obesity.metabolism is found in obesity.

.. Incidence of hypothyroidism andIncidence of hypothyroidism and

infertility is moreinfertility is more



GASTROINTESTINAL SYSTEMGASTROINTESTINAL SYSTEM

.. HHigher risk of aspiration of gastricigher risk of aspiration of gastric

contents and development of contents and development of pneumonia due to-pneumonia due to-

- raised intra abdominal- raised intra abdominal

pressurepressure- high volume(>25ml) and low- high volume(>25ml) and lowpH (<2.5)of gastric contentspH (<2.5)of gastric contents

- delayed gastric emptying- delayed gastric emptying

- high incidence of hiatus hernia- high incidence of hiatus herniaand gastro esophageal reflux diseaseand gastro esophageal reflux disease

.. Fatty infiltration of the liver andFatty infiltration of the liver and

gall stone incidence increasesgall stone incidence increases



.. Increased incidence of the malignanciesIncreased incidence of the malignancies

such as rectal,prostate,endometrial,gallsuch as rectal,prostate,endometrial,gall

bladder and breast.bladder and breast.

MUSCULOSKELETAL SYSTEMMUSCULOSKELETAL SYSTEM

.. Increased incidence of osteoarthritis of Increased incidence of osteoarthritis of

weight bearing joints and back painweight bearing joints and back pain

.. Significant increase in the incidence of Significant increase in the incidence of

wound infectionwound infection



THROMBOEMBOLIC DISEASETHROMBOEMBOLIC DISEASE

.. Two Two fold increase in the incidence of fold increase in the incidence of venous thrombosis due to –venous thrombosis due to –

- reduced mobility leads to venous- reduced mobility leads to venous

stasisstasis

- main circulating anticoagulant- main circulating anticoagulant-antithrombin III is diminished in morbidly-antithrombin III is diminished in morbidly

obeseobese

- decreased fibrinolytic activity in- decreased fibrinolytic activity inobeseobese



INFLUENCE OF OBESITY ON DRUGINFLUENCE OF OBESITY ON DRUG

HANDLING AND DOSINGHANDLING AND DOSING

Obesity alters the pharmacokinetic asObesity alters the pharmacokinetic aswell as the pharmacodynamic profile of awell as the pharmacodynamic profile of adrug.drug.

VOLUMEVOLUME OFOF DISTRIBUTIONDISTRIBUTION : the: thedistribution of drug changes during obesitydistribution of drug changes during obesityand is due to-and is due to-

- smaller than normal fraction of total- smaller than normal fraction of totalbody waterbody water

- greater than normal adipose tissue- greater than normal adipose tissuecontentcontent

- increased lean bod mass andincreased lean bod mass and



-- increased blood volume and cardiacincreased blood volume and cardiacoutputoutput

- increased concentration of bloodincreased concentration of bloodconstituents such as free fattyconstituents such as free fattyacids,triglycrides, cholesterol ,aacids,triglycrides, cholesterol ,a11 acidacidglycoprotein.glycoprotein.

PLASMAPLASMA PROTEINPROTEIN BINDINGBINDING : No significant: No significantchange is seenchange is seen

DRUGDRUG CLEARANCECLEARANCE : Renal clearance is: Renal clearance isincreased due to increased renal bloodincreased due to increased renal bloodflow ,increased GFR and tubular secretion.flow ,increased GFR and tubular secretion.

drug metabolism in liver may bedrug metabolism in liver may bedecreased as obesity decreases hepaticdecreased as obesity decreases hepaticblood flow .blood flow .



As a general rule,the hydrophilicAs a general rule,the hydrophilic

drugs have relatively similar absolutedrugs have relatively similar absolute

volume of distribution,elimination half lifevolume of distribution,elimination half life

and metabolic clearance in the obese andand metabolic clearance in the obese andthe non obese,while the fat soluble drugsthe non obese,while the fat soluble drugs

have an increased volume of have an increased volume of

distribution,more selective distribution todistribution,more selective distribution to

fat stores and a longer elimination half lifefat stores and a longer elimination half lifeand therefore prolonged effect in theand therefore prolonged effect in the

obese compared to the non obese.obese compared to the non obese.



INHALATIONAL ANAESTHETICSINHALATIONAL ANAESTHETICS

.. Obese patients metabolise allObese patients metabolise allhalogenated anaesthetics to ahalogenated anaesthetics to agreater extentgreater extent

.. Halothane and enflurane areHalothane and enflurane are

metabolised more leading tometabolised more leading toincreased levels of serum and urinaryincreased levels of serum and urinaryfluoride concentrationfluoride concentration

.. Sevoflurane produces slightSevoflurane produces slightincrease in fluoride concentrationincrease in fluoride concentrationafter prolonged exposureafter prolonged exposure

.. No change after isoflurane andNo change after isoflurane and

desflurane anaesthesia.so theydesflurane anaesthesia.so they



.. Nitrous oxide has limited usefulnessNitrous oxide has limited usefulnessbecause of high demand for oxygen.because of high demand for oxygen.

INTRAVENOUS INDUCTION AGENTSINTRAVENOUS INDUCTION AGENTS

.. Thiopentone is highly lipophilic and has Thiopentone is highly lipophilic and has

increased volume of distribution andincreased volume of distribution andelimination half life but clearance remainselimination half life but clearance remainsunchanged.So larger absolute dose butunchanged.So larger absolute dose butsmaller dose per unit weight is suggested.smaller dose per unit weight is suggested.

.. Propofol is also highly lipophilic and thePropofol is also highly lipophilic and theabsolute dose should be increased.absolute dose should be increased.



NEUROMUSCULAR BLOCKING AGENTSNEUROMUSCULAR BLOCKING AGENTS

.. The absolute dose of succinyl The absolute dose of succinylcholine should be high as there ischoline should be high as there is

increased plasma pseudo- cholinesteraseincreased plasma pseudo- cholinesterase

levellevel

.. Recovery time is prolonged in caseRecovery time is prolonged in caseof vecuronium due to impaired hepaticof vecuronium due to impaired hepatic

clearanceclearance

.. Obesity does not alter theObesity does not alter theelimination of atracurium.so atracurium inelimination of atracurium.so atracurium in

same dose per total body weight is the nmsame dose per total body weight is the nm

blocking agent of choiceblocking agent of choice

.. Duration of action of rocuronium isDuration of action of rocuronium is



..pancuronium is a low lipid solublepancuronium is a low lipid solubledrug, so total dose per kg body weight isdrug, so total dose per kg body weight issimilar.similar.

OPIOIDSOPIOIDS

.. Kinetics of fentanyl,alfentanyl andKinetics of fentanyl,alfentanyl andsufentanyl are quite unpredictable insufentanyl are quite unpredictable in

obese patientsobese patients .. The pharmcokinetic of remifentanyl is The pharmcokinetic of remifentanyl is

similar in obese and lean patients.Thissimilar in obese and lean patients.Thischaracterstic of remifentanyl suggests it tocharacterstic of remifentanyl suggests it to

be the analgesic of choice in obesebe the analgesic of choice in obesepatientspatients

LOCAL ANAESTHETICSLOCAL ANAESTHETICS

.. Intra venous lignocaine can be givenIntra venous lignocaine can be given



according to total body weightaccording to total body weight

.. The dose requirements of local The dose requirements of localanaesthetics for intrathecal and extraduralanaesthetics for intrathecal and extradural

anaesthesia in obese patients are reducedanaesthesia in obese patients are reduced

by 20 – 25%by 20 – 25%

SEDATIVES/HYPNOTICSSEDATIVES/HYPNOTICS

.. Midazolam and diazepam showsMidazolam and diazepam shows

increased volume of distribution andincreased volume of distribution andprolonged elimination half life,so increaseprolonged elimination half life,so increase

in absolute dose requirement .Duration of in absolute dose requirement .Duration of

action is prolonged specially after infusionaction is prolonged specially after infusion



ANAESTHETIC IMPLICATIONSANAESTHETIC IMPLICATIONS

Obese patients can undergo surgery for aObese patients can undergo surgery for avariety of causes – emergency/routine asvariety of causes – emergency/routine as

well as surgeries for the treatment of well as surgeries for the treatment of

obesity itself.the altered physiologicalobesity itself.the altered physiological

state in these group of patients can makestate in these group of patients can makeanaesthetising them a really challenginganaesthetising them a really challenging

task.task.

PRE-OPERATIVE ASSESMENTPRE-OPERATIVE ASSESMENT

.. A thorough clinical examination withA thorough clinical examination with

excellent relevant history looking forexcellent relevant history looking for

hypertension,signs of hypertension,signs of



cardiac failure (increase in JVP,addedcardiac failure (increase in JVP,addedsounds,pulmonarysounds,pulmonarycrackles,hepatojugular reflex andcrackles,hepatojugular reflex andperipheral oedema) and IHD.peripheral oedema) and IHD.

.. A through assessment of theA through assessment of the

respiratory system for OSA.respiratory system for OSA. .. Special emphasis on respiratorySpecial emphasis on respiratory

and CV system along with renal ,GITand CV system along with renal ,GIT

(h/o GERD )and hepatic systems(h/o GERD )and hepatic systems .. Reassurance to the patients whileReassurance to the patients whiledoing PAC as these group of patientsdoing PAC as these group of patientsoften suffer from depression,hiddenoften suffer from depression,hidden

anxiety and fearanxiety and fear



.. Importance of early ambulation andImportance of early ambulation andphysiotherapy should be emphasizedphysiotherapy should be emphasized

onon .. Drug and treatment history shouldDrug and treatment history should

be thorough and in detailbe thorough and in detail

.. Careful assesment of the intubatingCareful assesment of the intubatingconditions should be made includingconditions should be made includingMallampatti grading,assesment of Mallampatti grading,assesment of the mobility of the head ,neck andthe mobility of the head ,neck and

jaw,dental status and oropharyngeal jaw,dental status and oropharyngealinspectioninspection

.. If difficult intubation isIf difficult intubation is

anticipated ,awake intubation mustanticipated ,awake intubation must



.. Assessment of veins for placing infusionAssessment of veins for placing infusion

.. Assessment of signs of DVTAssessment of signs of DVT

.. Assessment of feet and back for soresAssessment of feet and back for sores

and ulcersand ulcers

If the patients are visited well inIf the patients are visited well in

advance then,advance then,

.. Advice weight loss by diet control andAdvice weight loss by diet control and

exerciseexercise

.. Cessation of smoking is advised and chestCessation of smoking is advised and chestphysiotherapy is initiated preoperativelyphysiotherapy is initiated preoperatively



PRE-OPERATIVE INVESTIGATIONSPRE-OPERATIVE INVESTIGATIONS

.. Hb%,BT,CT,Blood sugar (fasting andHb%,BT,CT,Blood sugar (fasting andpost prandial)post prandial)

.. Liver and Renal function testsLiver and Renal function tests

.. X-rays of the neck and chestX-rays of the neck and chest

.. ECG and Echocardiography(coronaryECG and Echocardiography(coronary

angiography,scintigraphy studies if angiography,scintigraphy studies if

required)required)

.. ABG in sitting and supine positionABG in sitting and supine position .. PFT in sitting and supine positionPFT in sitting and supine position

.. Lipid profileLipid profile

.. Thyroid function test and Adrenal Thyroid function test and Adrenal



AAn informed and written consent mustn informed and written consent must

be ensured and checked.be ensured and checked.

PRE-OPERATIVE INSTRUCTIONS ANDPRE-OPERATIVE INSTRUCTIONS AND

PRE-MEDICATIONSPRE-MEDICATIONS

.. Weight to be recordedWeight to be recorded

.. Narcotics and sedatives are best avoidedNarcotics and sedatives are best avoided

.. Intramuscular and subcutaneousIntramuscular and subcutaneous

injections are best avoided because of injections are best avoided because of unpredictable absorptionunpredictable absorption

.. Antacid prophylaxis :H2 blockers givenAntacid prophylaxis :H2 blockers given

at nightat night



and two hours before surgery andand two hours before surgery and

metoclopromide given 12hrs and 2hrsmetoclopromide given 12hrs and 2hrsbefore surgerybefore surgery

.. To continue medications for hypertension To continue medications for hypertension

and diabetes mallitusand diabetes mallitus

.. Oral antacid may be givenOral antacid may be given

.. DVT prophylaxis should be initiatedDVT prophylaxis should be initiated

.. Prophylactic antibioticsProphylactic antibiotics

.. Patients with diagnosed OSA on treatmentPatients with diagnosed OSA on treatmentwith CPAP should take their equipment towith CPAP should take their equipment to

the OT for post operative usethe OT for post operative use



.. Early establishment of a peripheralEarly establishment of a peripheral

venous access or a central venous linevenous access or a central venous line

POSITIONINGPOSITIONING

.. Two operating tables may be joined and Two operating tables may be joined and

extra padding must be used.lateral wedgeextra padding must be used.lateral wedgeor tilt may be used.or tilt may be used.

.. Trendelenberg and prone positions Trendelenberg and prone positions

should preferably be avoidedshould preferably be avoided

.. Appropriate man power to shift patientsAppropriate man power to shift patients

are necessaryare necessary



MONITORINGMONITORING

.. Invasive blood pressure in all but mostInvasive blood pressure in all but most

minor surgeriesminor surgeries .. ECG,Pulse oximetry, Capnography,ECG,Pulse oximetry, Capnography,

Temperature probes Temperature probes

.. Neuromuscular monitoring is essentialNeuromuscular monitoring is essential .. Others based on indication andOthers based on indication and

availabilityavailability



GENERAL PRINCIPLES OFGENERAL PRINCIPLES OF

ANAESTHESIA IN OBESEANAESTHESIA IN OBESE

REGIONAL technique to be used wheneverREGIONAL technique to be used whenever

feasible.feasible.

GENERAL ANAESTHESIAGENERAL ANAESTHESIA

.. Combined regional and GA is preferableCombined regional and GA is preferable

to GA aloneto GA alone

.. Ideally two anaesthesiologists should beIdeally two anaesthesiologists should bepresentpresent



POTENTIAL PROBLEMS DURING GAPOTENTIAL PROBLEMS DURING GA

.. Maintenance of an adequate airway,Maintenance of an adequate airway,

.. Risks of regurgitation and aspiration of Risks of regurgitation and aspiration of

gastric contentsgastric contents

.. Spontaneous respiration under GA leadsSpontaneous respiration under GA leads

to both hypoxia and hypercarbiato both hypoxia and hypercarbia .. Limited range of head ,neck and jawLimited range of head ,neck and jaw

movementsmovements

.. Short ,fat neckShort ,fat neck



AIRWAY MANAGEMENT IN OBESEAIRWAY MANAGEMENT IN OBESE

.. Other than for the briefest of GA inOther than for the briefest of GA in

selected patients,endotracheal intubationselected patients,endotracheal intubationshould be used in all obese patientsshould be used in all obese patients

.. Anterior displacement of the mandible isAnterior displacement of the mandible is

less helpful to relieve airwayless helpful to relieve airwayobstruction.Mask ventilation can beobstruction.Mask ventilation can be

difficult and may require an assistantdifficult and may require an assistant

.. There seems to be no correlation There seems to be no correlation

between BMI and difficult laryngoscopybetween BMI and difficult laryngoscopy .. Patients may be pre oxygenated in 25Patients may be pre oxygenated in 25

degree propped up position to achievedegree propped up position to achieve

higher oxygen tensionshigher oxygen tensions



.. The anaesthesiologist should be The anaesthesiologist should be

prepared with a full range of aids forprepared with a full range of aids fortracheal intubation such as short –tracheal intubation such as short –

handled laryngoscope,polio blade,McCoyhandled laryngoscope,polio blade,McCoy

laryngoscope , gum elastic bougies,laryngoscope , gum elastic bougies,

standard and intubating laryngeal maskstandard and intubating laryngeal maskairway.airway.

.. Equipment for emergencyEquipment for emergency

cricothyrotomy should be kept ready and acricothyrotomy should be kept ready and a

capnograph available to confirm correctcapnograph available to confirm correct

placement of the endotracheal tube.placement of the endotracheal tube.



.. If no difficulty in intubatingIf no difficulty in intubatingconditions is anticipated,then inconditions is anticipated,then in

majority of the patients a rapidmajority of the patients a rapidsequence intravenous induction withsequence intravenous induction withthiopentone(4mg/kg,max. 500 mg)thiopentone(4mg/kg,max. 500 mg)or propofol ; and succinylcholineor propofol ; and succinylcholine

(1mg/kg of IBW or even TBW ;120(1mg/kg of IBW or even TBW ;120-140 mg appear satisfactory)-140 mg appear satisfactory)combined with cricoid pressure is acombined with cricoid pressure is a

safe method of securing the airway.safe method of securing the airway. .. In difficult cases the choice of In difficult cases the choice of technique and equipment is atechnique and equipment is apersonal one.An awake fibre opticpersonal one.An awake fibre optic

approach for tracheal intubationapproach for tracheal intubation



.. Capnography is essential to confirm theCapnography is essential to confirm the

correct placement of the ETT.correct placement of the ETT.

.. Bullard laryngoscope is an alternative inBullard laryngoscope is an alternative in

trained hands.trained hands.

.. The intubating LMA has been shown to The intubating LMA has been shown to

be effective airway device.be effective airway device.

.. The proseal LMA can also be used. The proseal LMA can also be used.

After intubation the patient should beAfter intubation the patient should be

ventilated with 100% oxygen and tidalventilated with 100% oxygen and tidalvolume of 12-15ml/kg .volume of 12-15ml/kg .



alveolar recruitment is an effectivealveolar recruitment is an effective

means of improving intra operativemeans of improving intra operative

oxygenation.the ventilatory strategyoxygenation.the ventilatory strategyconsists of-consists of-

- sustained lung insufflations- sustained lung insufflations

- a high inspired oxygen fraction- a high inspired oxygen fraction- large tidal volumes- large tidal volumes

- positive end expiratory pressure- positive end expiratory pressure

- sustained inspiratory pressure of atleast- sustained inspiratory pressure of atleast40 cm of water to fully reverse40 cm of water to fully reverse

anaesthesia induced atelectesisanaesthesia induced atelectesis



FLUID MANAGEMENTFLUID MANAGEMENT

The total body water is reduced in The total body water is reduced in

obese patients from 65% toobese patients from 65% to40%.there is increased chance of 40%.there is increased chance of fluid loss due to –fluid loss due to –

- increased sweating- increased sweating- enhanced bleeding- enhanced bleeding

- prolonged surgery- prolonged surgery

But as most of these patients are inBut as most of these patients are incardiac compromised state socardiac compromised state sopreferably a CVP line or a Pulmonarypreferably a CVP line or a Pulmonaryartery catheter should be used toartery catheter should be used to

uide the re lacement volumes.uide the re lacement volumes.



EXTUBATIONEXTUBATION

Extubation should be done only whenExtubation should be done only when

patients are fully awake with adequatepatients are fully awake with adequate

cough reflex and have complete reversalcough reflex and have complete reversal

of neuromuscular blockage.of neuromuscular blockage.

During post extubation periodDuring post extubation period,aspiration of gastric contents and post,aspiration of gastric contents and post

extubation pulmonary oedema may occur.extubation pulmonary oedema may occur.



POST OPERATIVE CAREPOST OPERATIVE CARE

.

.Post operatively the patients should bePost operatively the patients should be

transferred to a PACU.transferred to a PACU.

.. Transportation should be done in semi Transportation should be done in semi

recumbent positionrecumbent position

.. Supplemental oxygen should be providedSupplemental oxygen should be providedand shivering avoided.and shivering avoided.

.. CPAP may be initiated post operatively inCPAP may be initiated post operatively in

patients with OSA or after upperpatients with OSA or after upperabdominal surgeryabdominal surgery

.. Post operative mechanical ventilationPost operative mechanical ventilation

may be required in patients with co-may be required in patients with co-

existing cardiacexisting cardiac



disease,hypercapnia,fever,infection,elderlydisease,hypercapnia,fever,infection,elderly

, anxious and un cooperative patients., anxious and un cooperative patients.

.. Supplemental oxygen may be requiredSupplemental oxygen may be required

for about 3 to 4 days post operatively.for about 3 to 4 days post operatively.

.. Early ambulation,DVTEarly ambulation,DVTprophylaxis,incentive spirometry andprophylaxis,incentive spirometry and

physiotherapy should be initiated.physiotherapy should be initiated.

.. Frequent change of position is importantFrequent change of position is important

and patients should be nursed at a 30 toand patients should be nursed at a 30 to

45 degree propped up position45 degree propped up position



POST OPERATIVE ANALGESIAPOST OPERATIVE ANALGESIA

.. Opioid induced ventilatoryOpioid induced ventilatorydepression is a concern and the intradepression is a concern and the intramuscular route is best avoidedmuscular route is best avoidedbecause of unpredictable absorption.because of unpredictable absorption.

.. It can be best provided with anIt can be best provided with anindwelling catheter placed earlier forindwelling catheter placed earlier forregional technique as it reduces theregional technique as it reduces theamount of opioid required.amount of opioid required.

.. Intravenous PCA is also effective inIntravenous PCA is also effective inrelieving pain and the dose should berelieving pain and the dose should bebased on IBW.based on IBW.

.. Analgesia can be supplementedAnalgesia can be supplemented



REGIONAL ANAESTHESIAREGIONAL ANAESTHESIA

.. Always a preferred optionAlways a preferred option .. The advantages are – The advantages are –

-airway intubation difficulties are-airway intubation difficulties are

avoidedavoided

- risk of gastric aspiration is reduced- risk of gastric aspiration is reduced

- more cardio vascular stability- more cardio vascular stability

- need for neuromuscular blockers- need for neuromuscular blockers

and potential problems with their reversaland potential problems with their reversalare avoidedare avoided

- patients remain awake and can- patients remain awake and can

communicatecommunicate

lesser post operative respiratorylesser post operative respiratory



- lesser post operative respiratorylesser post operative respiratory

complicationcomplication

- the incidence of PDPH is lower- the incidence of PDPH is lower- early ambulation and lesser thrombo- early ambulation and lesser thrombo

embolic complicationembolic complication

DIFFICULTIES IN REGIONALDIFFICULTIES IN REGIONAL

ANAESTHESIAANAESTHESIA

- excess adipose tissues conceal bony- excess adipose tissues conceal bony

landmarkslandmarks- requirement of longer than usual- requirement of longer than usual

spinal and epidural needlesspinal and epidural needles



-- incidence of inadverdant duralincidence of inadverdant dural

puncture is 2-8 times higherpuncture is 2-8 times higher

-- local anaesthetic requirement islocal anaesthetic requirement is

reducedreduced

- high blocks are common- high blocks are common

- epidural anaesthetic drugs tend not- epidural anaesthetic drugs tend notto fix quickly in the obese with a tendencyto fix quickly in the obese with a tendency

for continued cephalad spreadfor continued cephalad spread

SPECIAL CIRCUMSTANCESSPECIAL CIRCUMSTANCES



SPECIAL CIRCUMSTANCESSPECIAL CIRCUMSTANCES

A.PAEDIATRIC POPULATIONA.PAEDIATRIC POPULATION

- Children heavier than 97- Children heavier than 97thth percentile weight have problemspercentile weight have problemsassociated with their obesityassociated with their obesity

- i.v. access is often a common- i.v. access is often a commonproblemproblem

- OSA is a frequent finding in- OSA is a frequent finding in

them as in Prader-Willi syndromethem as in Prader-Willi syndrome

B.OBSTETRICS AND OBESITYB.OBSTETRICS AND OBESITY

- all attending complications are- all attending complications are



-- higher maternal weight beforehigher maternal weight beforepregnancy increases the risk of latepregnancy increases the risk of late

fetal deathfetal death- regional anaesthesia is always a- regional anaesthesia is always a

better choicebetter choice

- siting an epidural catheter during- siting an epidural catheter duringlabour is a better optionlabour is a better option

- extra long touhy needle or spinal- extra long touhy needle or spinalneedle may be needed for centralneedle may be needed for centralneuraxial blocksneuraxial blocks

- over all the sitting position is- over all the sitting position ispreferred for central neuraxial blockspreferred for central neuraxial blocks

- local anaesthetic requirement- local anaesthetic requirement



C.BARIATRIC SURGERYC.BARIATRIC SURGERY

- Weight reductive surgeries- Weight reductive surgeries- indications : BMI > 40kg/m- indications : BMI > 40kg/m²²

BMI > 35kg/m² withBMI > 35kg/m² with

comorbiditiescomorbidities

dietary attempts have beendietary attempts have been

ineffectiveineffective

- combination of thoracic epidural- combination of thoracic epidural

anaesthesia with general anaesthesia hasanaesthesia with general anaesthesia hasbeen described as the ideal techniquebeen described as the ideal technique



D.OBESITY AND CRITICAL CARED.OBESITY AND CRITICAL CARE

- Despite the widely held belief that- Despite the widely held belief thatoutcome is poor for morbidly obeseoutcome is poor for morbidly obese

patients admitted into the ICU ,obesity ispatients admitted into the ICU ,obesity is

not included as a variable in thenot included as a variable in the

development of the APACHE II and IIIdevelopment of the APACHE II and IIIscoring systemsscoring systems

- during ventilation ,tidal volume based- during ventilation ,tidal volume based

on the IBW should be used initially andon the IBW should be used initially and

then adjusted according to inflationthen adjusted according to inflationpressure and ABG analysispressure and ABG analysis

- nutritional support- nutritional support

- weaning may be difficult due to:- weaning may be difficult due to:



..high oxygen requirementhigh oxygen requirement

.. Increased work of breathingIncreased work of breathing

.. Decreased lung volumesDecreased lung volumes

.. v/q mismatchv/q mismatch



CONCLUSIONCONCLUSION

Obese patients are not just “bigger orObese patients are not just “bigger or

heavier” patients.Changes in bodyheavier” patients.Changes in body

physiology set them apart from the nonphysiology set them apart from the non

obese individuals.They pose tremendousobese individuals.They pose tremendouschallenges to the anaesthesiologists. Butchallenges to the anaesthesiologists. But

understanding theunderstanding the

pathophysiology,anticipating the problemspathophysiology,anticipating the problems

and preventing calamities by a systematicand preventing calamities by a systematicapproach will certainly bring down theapproach will certainly bring down the

complication rate.complication rate.





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Anaesthesia in Surgery in Obese Patients - Copy