Thoracic surgery – assessment

 

Issues:

Resection

What is the risk?

·     i.e. the three-headed dog

·     Proceed vs optimize vs cancel

·     Ward vs ICU post-op

Can the risk be reduced?

·     Lifestyle: stop smoking

·     Physio: sputum clearance

·     Drugs: bronchodilators, antibiotics, glucocorticoids

Cancer

What is the tumour up to?

·     Mass effects -> airway, SVC, heart

·     Metastases -> brain, bone, liver

·     Metabolic -> paraneoplastic

·     Medication -> cytopaenias, organ dysfunction

Other

What is the rest of the patient like?

·     Airway (difficulty?)

·     Breathing (comorbidities?)

·     Circulation (comorbidities?)

 

The three-headed dog:

Predicted decrements

Default method:

·     Number of segments removed

Diagram Description automatically generated

If line ball:

·     Assess contribution of diseased segments

o   i.e. V/Q split lung function test

·     Try before you buy:

o   i.e. can occlude L/R bronchus and L/R pulmonary artery

o   Assess PaO2, PaCO2, mPAP

o   Generally impractical

·     Other considerations:

o   The above predict long term changes

o   Function will get worse immediately post-op, esp. if thoracotomy

o   FEV1 may deteriorate less than expected if severe COPD

o   The surgeon and physician are gatekeepers, not the anaesthetist

1.Mechanical

ppoFEV1:

·     >40%: ok

·     20-40%: maybe

·     <20%: nope

Other tests:

·     FVC

·     MVV

·     RV/TLC

2.Parenchymal

ppoDLCO:

·     >40%: yes

·     20-40%: maybe

·     <20%: nope

Other tests:

·     PaO2

·     PaCO2

3.Cardiopulmonary

VE/VCO2 slope:

·     >35: high risk of respiratory complications and death

·     Strongest predictor

VO2max:

·     >20mL/kg/min: ok

·     15-20: maybe

·     <15: nope

(two flights of stairs = VO2 12)

Anaerobic threshold:

·     <10mL/kg/min: nope

·     Especially if ischaemia or failure

6MWT:

·     Distance >650m: ok

·     Desat <4%: ok

·     N.B. 6MWT / 30 ≈ VO2max

 

 

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