preparing patient for op

8/14/2019 Preparing Patient for Op

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Objectivey

To reduce postponement rate of elective surgicalcases.

y Identify of potential problems which may arise

during perioperative anasthetic management.


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Assessment of the patienty Confirmation of patient identification, review of diagnosis, proposed surgical procedure and

consent for surgery and anaesthesia.

y History taking, physical examination, review result, review past and current medication,potential anaesthetic problem such as difficult airway, obesity and cardiopulmonary disease

y Classify physical status according to ASA.

y Relevant preop preparation such as optimisation of medical treatment , preop chest physio andGSH/GXM blood or blood product

y Give clear instruction on medication: whether to continue or omit the dose and when to take

their medication on the day of surgery.

y Clear instruction on time to comment fasting especially for children.

y Prescribe premedical drugs


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American society of anaesthesiologists physical status

clasification and overallmortality rate

Category Description of Patient Mortality (%)

I Healthy patient 0.06-0.08

II Mild systemic diseasewith no functionallimitation

0.3-0.4

III Severe systemic diseasewith definite functionallimitation

1.8-4.3

IV Severe systemic diseasethat is a constant treat tolife

7.8-23.4

V Moribund patientunlikely to survive 24hours with or withoutoperation

9.4-50.7

E Denotes emergency surgery


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Guidelines for preoperative fastingAge Nature of oral

intakeLength offasting(hour)

Amount of fluidallowed

< 6 months Clear fluid

Breast milkFormula milk

2

34

20 ml/kg

6 months to 5years

Clear fluidFormula milksolid

246

10ml/kg

> 5 years Clear fluidsolid

26

10ml/kg

Adult, morninglist

Clear fluidsolid

2Fast from 12MN

Adult afternoonlist

Clear fluidsolid

2Fast from 8am

after lightbreakfast

*clear fluid- water, clear fruit juice, glucose water, not carbonated drinks, soup, milk, coffee or tea*light breakfast-maximum of 2 slices of bread or 4 pieces of biscuits with milk, tea or coffee


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HypertensionCoronary artery diseaseRespiratory diseaseDiabetes MellitusRenal Disease


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Hypertension

Significance of hypertension for anaesthesiolosist

y Hypertensive patients are likely to have comorbidities which add to theanaesthetic risk, such as accelerated atherosclerosis leading to coronary

artery disease or cerebrovascular disease , renal and enocrine disorders

y Untreated or poorly treated hypertensive patients show exagerratedcardiovascular responses and BP lability during anaesthesia, which

may precipitate adverse myocardial or cerebrovascular eventsintraoperatively


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2. Assessment of target organ damage and associatedmedical conditions

y CVS: hypertensive heart disease (Left ventricular hypertophy,diastolic dysfunction), heart failure, coronary heart disease withsymptomatic or silent MI. Mandatory tests are ECG and CXR.

y Renal system: even mild hypertensives may have a degree of renalimpairment. Check RP

y CNS : Cerebrovascular disease (TIA, ischaemic or haemorrhagicstroke). Check fundoscopic examinations for hypertensive changes.

y Other concomitant disease : DM, hypercholesterolaemia, obesity ,PVD


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3. Acceptability for surgery

y Elective surgery should be deferred if BP is persistently elevated,diastolic BP>110 or systolic BP > 180

y The risk of delaying emergency surgery may outweigh those ofproceeding in the face of uncontrolled hypertension. IVantihypertensive agents such as Esmolol, Labetolol or Hydralazine

maybe required to acchieve rapid BP control. However dramaticacute reduction in BP may also be fraught w risk and should beavoided.


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Anaesthetic managementy It is necesssary to provide adequate sedation and anxiolysis to be

prevent anxiety induced tachycardia and hypertension

y Antihypertensive should be continued on the morning of surgery. ACEIand Angiotensin II receptor antagonist may be omitted if preop BP notmarkedly elevated, as those meds have potential to interact withanaesthetic agents to produce hypotension

BACK


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Preop Assessment1. Historyy Previous MI, if any

y Details include the use of thrombolytic agent (eg Streptokinase) in acutemanagement, any complications during the acute period, length ofCCU andhospital stay, examine all hosp records if available

y Enquire about further Sx such chest pain, arrythmias, or decreased ETfollowing MI

y Cardiac Sxy Angina: quantify the frequency, severity, site, character, aggravating and

relieving factors, but on going MI maybe silent in patient with autonomicneuropathy

y Heart failures: elicit present or history of pedal oedema, orthopnea, PNDy

Symptomatic arryhmias: elicit H/o palpitation or syncopey Functional status

y Commonly quantified according to the classification proposed by the New YorkHeart Association or Canadian Cardiovascular society


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NYHA functional classification

Class Functional status 1 year mortality

I No limitations of physiacl activity, no symptoms withordinary exertions

5-10%

II Slight limitation of physical activity but comfortable atrest. Ordinary activity results in fatigue, palpitation,dypsnea or angina

10-15%

III Marked limitation or physical activity. Less than ordinaryactivity leads to symptoms. Asymptomatic at rest

15-20%

IV Inability to carry on any physical activity withoutdicomfort. Symptoms of cardiac insufficiency are presentat rest. With any activity increased discomfort inexperiened

20-50%


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CCS functional classificationClass Functional status

I Ordinary physical activity, such as walking and climbing stairs,does notcsuse angina. Angina occurs with strenuous or rapid or prolongedexertion at work or recreation

II light limitation of ordinary activity. Angina occurs with walking orclimbing stairs rapidly, walking up hill, walking or stair climbing after

meals or in cold or in wind or under emotional stress, or only during thefew hours after awakening. Angina occurs when walking more than twoblocks on the level or climbing more than 1 flight of ordinary stairs at anormal pace and in the normal conditions.

III Marked limitation of ordinary physical activity . Angina occurs withnwalking 1 or 2 blocks on the level and climbing 1 f light of stairs innormal conditions and at a normal pace.

IV Inability to carry on any physical activity without discomfort. Angina

maybe present at rest.


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Duke Activity Status Index

1-4 MET Take care of oneself (eat, dress or use the toilet

Do light work around the house (dusting or washing dishes)Walk indoors around the houseWalk a block or two on level ground at 3-5km/hr

5-9 MET Climb a flight of stairs or walk up a hillWalk on level ground at >6km/hr

Run a short distanceDo heavy work around the house (scrubbing f loors or lifting heavy furniture)Participate in moderate recreational activities (Golf, bowling, dancing, doubletennis, throwing a baseball or football)

>10MET Participate in strenuous sports (swimming, single tennis, football, basketball,

skiing)


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y Past and present treatment

y Assess compliance and response to treatment

y Patient may also receive treatment for concomitant medical conditionssuch as Hypertension, DM, hypercholesterolaemia, and/or hyperuricaemia

y Patient may have implanted pacemaker or otomatic implantable

cardioverter defivrillator(IC

D)y Previous (CABG), PTCA is associated with an increase risk of stent

thrombosis and infarction if surgery is perform within 6 week. Surgeryshould be deferred until 3 month later

y

Risk factor identification with increased risks of perioperative mobidity ormortality associated with

y Demographics such as gender, age > 70 years

y Obesity

y Smoking

y Comorbid condition: DM, hypertension, hypercholestrolaemia, PVD, renaldysfunction , COPD, CVA

y Family history ofCAD or cardiac death


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2. Physical examination

y Features of significant include uncontrolled hypertension or cardiacarrythmia, signs of heart failure(raised jugular venous pressure,oedama, hepatomegaly, cardiomegaly, pulmonory oedama), presenceof sternotomy scar

3. Investigations

y Routine Ix include FBC, BUSE, RBS, ECG and CXR

y Further Ix are indicated in theses cases:

y Patients with atypical symptoms which pose a problem todiagnosis

y Patients with Sx of heart failure or frequent chest pain

y H/o recent MI (


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y Echocardiographyy

Stress test

y Myoview scany This is the form of radionuclide scan in which thallium is taken up by

viable myocardial cells as myocardial perfusion is increased with

dipyridamole, a coronary vasodilatory Infarcted areas remained as fixed defects whereas ischaemic

myocardium appears as defects which are reversible reperfusion later.

y 24Hour Holter monitoring

y Angiography

y This is the gold standard to quantify cardiac statusy Due to its invasive nature with carries its own morbidity and mortality,

this procedure is indicated only in unstable coronary syndromes, ofuncertain stress test in high risk patients for major surgery, and inpotential candidates for coronary revascularization


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Surgery-Related Predictors for Risk ofPerioperative Cardiac Complications

High risk Intermediate risk Low risk

Emergency surgeryAnticipated increasedblood loss Aortic orperipheral vascular

surgery

Abdominal or thoracicsurgery Head and necksurgeryCarotidendarterectomy

Orthopedic surgeryProstate surgery

Breast surgeryCataractsurgery Superficialsurgery Endoscopy


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Patient-Related Predictors for Risk ofPerioperative Cardiac Complications

Major clinical

predictors

Intermediate clinical

predictors

Minor clinical

predictors

Myocardial infarction


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The risk of surgery and anaesthesia should be conveyed to patient:y Mild CAD:consent

y Reassurance and allay anxiety

y Moderate to severe CAD:

y Obtain high risky Optimize medical treatment

y Discussion w surgeon whether to limit duration and extent ofsurgery

y Institute close perioperative monitoring in ICU, CCU or HDWy Ensure early detection and aggrasive treatment of haemodynamic

disturbances


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Premedicationy Evidence for the prophylactic use of -adrenergic antagonists to reduce

MI is compelling, and should be considered in all high risk patients.They should be started 2 weeks before surgery and continued in post-

op period

y Patients usual cardiovascular medication except aspirin should beserved on the morning of surgery

y Patient should be adequately sedated to avoid anxiety-inducedhypertension and tachycardia

BACK


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Implications for anaesthetic management:y Acute consequences of untreated or poorly treated DM include osmotic diuresis with

dehydration, DKA or hyperosmolar non-ketotic hyperglycaemic crisis

y As result of diabetic nephropathy, renal excretion of anaesthetic drugs and othermedication may be impaired leading to prolonged pharmacological effect or overdosages.

y Autonomic neuropathy, affecting 30-40% of diabetic patients, may give rise to delayedgastric emptying, perioperative hypothermia, postural hypotension, abnormal cardiacreflexes, and silent MI.

y Altered consciousness may occur as a result of hypoglycaemia, hyperglycaemic crisis orcerebrovascular insufficiency.

y In situations of cardiac arrest and cerebral ischaemia, diabetic patients have a worseneurological outcome compared to non diabetics. This is probably due to presence oflactic acidosis as a results of anaerobic metabolism.

y Risk of infection is high, wound healing, may be delayed in the presence of poor diabetic

control, and incidence of chest infection is higher


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Pre op assessmenty Determine the type and duration of DM

y Nature, duration and compliance

y Blood glucose control (HBA1C Normal 3.8-6.4%)

y Identify and assess severity of associated medical conditions:

y CVS : hypertension, CAD, Cerebrovascular disease, PVD

y Renal system: diabetic neuropathyy CNS: peripheral neuropathy, autonomic neuropathy

y Eyes: Premature cataract, diabetic neuropathy


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P

eriopm

anagem

enty If possible, the patient should be scheduled early in the OT listto limit the duration ofpreop fasting

y Bedside blood glucose concentration usually adequate and it should be maintainedbetween 6-10mm/L

y In Minor surgery (surgery which require post-op fasting until post-nausea)y

Type 1 DMy Long acting should be substituted with short or intermediate acting insuliny Omit morning dose of insulin if BG


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Preoperative assessment

y Aimed at determining the extent of the disease in terms of renal function andinvolvement of other organs, and evaluate the risk of developing post op ARF

y Baseline Ix include FBC, blood glucose, RP, coagulation screen, ECG , CXR

y Blood:

y A lower Hb concentration (down to 6g/dL) may be accepted, and blood tranfusion isonly indicated if:

y Symptomatic

y Patient is scheduled to undergo a major surgery with anticipation of massiveblood loss

y Patient has concomitant illness such as severe cardiac or pulmonary disease

y Transfuse blood during dialysis to avoid f luid overload

y Use washed red blood cells if the patient is a potential renal transplant recipient

BACK


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y Dialysis:

y HD is usually done during the 24H preceeding elective surgery

y Send FBC, RP, blood glucose after dialysis and review results

y PD can be continued untill just before surgery. The dialysate should be drained prior

to surgery for optimal respiratory function

y Patients medication including antiHPT should be continued


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Objective of preop asessmenty Recognition of the underlying chronic pulmonary

disease

yAssessment of the patients functional reserve

y Treatment of any reversible acute problems


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AsthmaPre op assessment:

y History:y Elicit details of the disease, age of onset, freq, freq, severity, triggering

and releaving factors, past history of hospital admissions or need for respsopport, past and current medications, compliance of treatment

y h/o allergy, known atopy

y Physical examination

y Investigation:y ABG useful as baseline in severe resp dysfunction

y Lung funtion test in selected patients to assess the severity of airway constrictionand its reversibility in response to bronchodilator

y X-ray may indicated in the presence of infection or if pneumothorax is suspected

y Premedicationy Patients usual medication should be served on morning of surgery

y Nebu bronchodilator ,ay be given 1 Hr before op


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COPDy Pre op preparation

y Cessation of smoking

y Treat underlying chest infection

y Treatment of reversible component of bronchoconstriction usingbronchodilators

y Chest physio and breathing exercise: incentive spirometryy Treatment of associated cor-pulmonale and right heart failure

y Oxygen therapy if indicated

y Relevant test in addition to routine investigation: FBC, CXR, ABG, Lung

function test

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Summary of Recommended Preoperative Laboratory Tests Depending ontheHistory and Physical Findings

Condition Indicated testing and other measures*Healthy patient12

40 years Add ECG and blood glucose (age >=45 years)

Cardiovascular disease12,18 ECG, chest radiographs, hemoglobin, electrolytes, BUN,

creatinine, glucose (age >=45 years or history of diabetes)

Recent MI (6 weeks ago), mildstable angina, compensated CHF,diabetes mellitus

Stress test if high-risk procedure or patient has low functionalcapacity; consider assessment of left ventricular function (i.e.,echocardiography)

Rhythm other than normal sinusrhythm, abnormal ECG, history ofstroke, advanced age, low functional

capacity

Stress test if high-risk procedure and patient has low functionalcapacity

Pulmonary disease12,23,24,31-33 Chest radiographs, hemoglobin, glucose (age >=45 years), ECG(age >40 years); provide patient with instructions for incentivespirometry or deep-breathing exercises

f d d b d


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Summary of Recommended Preoperative Laboratory Tests Depending ontheHistory and Physical Findings

Condition Indicated testing and other measures*Asthma Pulmonary function testing or peak flow rate to assess disease

status

COPD Consider pulmonary function testing and arterial blood gasanalysis for assessment of disease severity

Cough Evaluate for etiology

Dyspnea Evaluate for etiology

Smoking Counsel patient to stop smoking 4 to 8 weeks before surgery

Obesity Provide patient with instructions for incentive spirometry ordeep-breathing exercises

Abdominal or thoracic surgery Provide patient with instructions for incentive spirometry ordeep-breathing exercises

Malnutrition34-36,38-40 Laboratory tests based on primary disease, plus albumin andlymphocyte count; if malnutrition is severe, consider postponing

surgery and providing preoperative supplementationECG = electrocardiogram; BUN = blood urea nitrogen; MI = myocardial infarction; CHF = congestive heart failure; COPD =chronic obstructive pulmonary disease.*--Other testing may be warranted based on the patient's surgical condition or other concomitant diseases.

preparing patient for op

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