Postoperative pulmonary complications are a major cause of morbidity and mortality after surgery. A thorough preoperative evaluation should identify patient risk factors like age, smoking history, lung disease, and functional status to predict risk. While tests like pulmonary function tests generally do not need to be routinely performed, they may help assess patients with significant lung conditions. Intraoperative and postoperative strategies can help reduce risk of complications in high-risk patients and include lung expansion techniques, appropriate pain management, and fluid optimization. Overall, comprehensive risk assessment allows for optimizing patient health and planning care to minimize pulmonary issues after surgery.

1. Ref.: North American Clinics Mar 2016
-Dr. Anuradha T
Jubilee Mission Medical College
Thrissur, India
Preoperative Evaluation
- Estimation of Pulmonary Risk

2.  Postop pulmo compli (PPC) are 2nd MC postop compli, 2-
5.6 %
 Poor outcomes, longer hospital stay, increased mortality
 Clinically significant PPC include... Bronchospasm,
atelectasis, exacerbation of underlying c/c lung
conditions, infection ( bronchitis, pneumonia), prolonged
mechanical ventilation and respiratory failure
 Surgical, anesthetic, pt factors contribute

3.  Aims of preop evaluation :
 Identify risk factors for PPC, change modifiable factors,
discuss risks with patients, optimise health before sx,
plan appropriate periop care
 Overall risk predicted using clinical data
 Do not routinely perform PFT before high risk non
cardiothoracic surgery

4. Pulmo Pathophysiology in Periop
 Mainly restrictive change,measured as reduction in
FRC
 no change in airway resistance.
 Splinting diaphragm- abnormal resp pattern- shallow,
rapid
 Atelectasis in bases,persists >24 hrs in 50% pts
 V/Q mismatch and increased shunt = hypoxia
 Upper abd sx: VC falls by 50%, FRC by 30%
 Lower abd lesser levels

5.  Intracranial, peripheral vascular, ENT 20% fall
 No change with extremity sx
 Decreased resp drive d/t anesthetics, opioids.
Inhibition of cough, impaired mucociliary clearance all
contribute to PPC

6. Preop Risk Assessment
 History & physical examn are most imp
 History must include :
 General health status
 Focused history on pulmonary symptoms- cough,
dyspnoea, exercise tolerance, pre existing lung
diseases

7. Physical Examination
 May help detect unrecognised lung disease
 Look for signs of......
 Asthma
 COPD
 OSA, PAH
 Right heart failure
 Neurological impairment
 Neuromuscular weakness
 Spinal deformity

8. Patient related risk factors for PPC
 General:
 Age,
 General health status, functional status
 Obesity, OSA
 Pulmonary HTN
 Heart failure
 Nutrition
 Neurological impairment

9. Pulmonary Factors :
 Smoking, > 20 pack year. >4 weeks cessation reduces PPC,
longer duration more benefit
 COPD- severe ,high risk for pneumonia, ventiltor dependance
>48 hrs.
 No prohibitive level of PFT below which sx ia absolutely C/I.
Benefit Vs Risk and proceed if indication is compelling.
 Exacerbations of c/c ds or a/c issues eg. Pneumonia- PPC. Are
adequate reason to postpone elective sx

10.  Asthma-
 unclear if h/o asthma carries more risk.
 Poorly controlled asthma – prone for hypoxi,
hypercapnea, bronchospasm, inadequate cough,
atelectasis, pulmo infection after sx.

 ACP 2006 suggest asthma is not a risk factor for PPC

11.  ILD :
 PPC after all types of sx in ILD is higher than general
population. But complications in other sx types are
not as high as after lung sx
 Upper respiratory infection :
 few data. Evidence is weak to recommend
postponement of elctive sx during URI. If URI occurs
within 2 weeks preop, adults may hv increased risk for
bronchospasm, laryngospasm and desaturation. But
this does not increase morbidity or long term
sequelae.

12. Procedure related Risk Factors
 Surgical site- more for upper abd sx. Highest for
esophagectomy
 Duration of surgery & complexity : >3-4 hrs had 40 % PPC. <
2 hours 8%

 Type of anesthesia and analgesia: GA alone more risk.
Consider spinal/epidural + light GA/ nerve blocks in high
risk

13.  Neuromuscular blockade: use intermediate acting
Atrac/Vec + monitoring to avoid any residual NMB
 Open Vs Lap sx : Unclear if PPC are reduced with lap.
Lap shorter stay, less pain, better spirometric values
 Emergency surgery : significant predictor of PPC

14. Preop Pulmonary tests
 PFT :
 Includes spirometry, flow volume loops,DLCO, V/Q scan,
CPET.
 Spirometry is MC. Do not predict PPC.
 2006 ACP guidelines do not reccomend routine preop
use before high risk sx. Should not be used as primary
factor to deny sx
 ABG : PaCO2 > 45mmnhigh risk for PPC. Not an absolute
C/I for major noncardiac sx.
 CXR: routine preop CXR hardly give additional info. ACP
recommends CXR in those with known cardiopulmonary
ds, > 50 yrs for high risk sx

15.  Exercise testing:
 VO2 max and anaerobic threshold are valid predictors of
periop morbidity and mortality.
 Simple ones like stair case climbing capacity and 6-min
walk test are accurate and show concordance with VO2
max
 ECHO : No evidence for routine preop use even in
advanced lung diseases.
 Advised for pts with severe lung disase having features of
right heart failure.
 Also in reduced exercise tolerance to r/o cardiac illness

16. Risk Scores for periop complications
 ARISCAT ( Canet) risk index- 2010: for PPC
 Gupta calculator for postop resp failure 2011: failure to
wean within 48 hours
 Gupta calculator for postop pneumonia-2013
 Arozullah respiratory failure index- 2000

17. CANET/ARISCAT risk index : 7 variables

22. Gupta calculator for postop resp failure
2011: failure to wean within 48 hours
 5 item calculator :
 - Type of surgery
 - Emergency surgery
 - Dependant functional status
 - Preoperative sepsis
 - ASA class

23. Periop Strategies to reduce PPC
 Strategies proven to reduce PPC in high risk pt are
 Preop :
 Smoking cessation > 8 weeks optimal
 Optimising airflow limitation in COPD, asthma
 Treat LRTI
 Lung expansion techniques- incentive spirometry and chest
physiotherapy

24.  INTRAOP :
 Consider intraop analgesia with spinal, regional or
epidural technque when indicated
 Avoid use of long acting NMB
 Intraop recruitment manouvers to prevent atelectasis
 Lap Vs open- consider less invasive surgery
 Fluid management- fluid optimisation with GDT

25.  POSTOP :
 Selective NG tube decompression after abdominal
surgery
 Nutritional support
 Lung expansion manouvers
 Epidural analgesia

26. Summary
 PPC account for 25% of deaths in the first postop
week
 Most significant predictors are – ASA class, functional
class, age, site and duration of surgery
 COPD, dyspnoea, smoking are only moderate risk
factors compared with pt related factors and site of sx
 Risk of PPC canbe predicted using scores with readily
available clinical data
 Do not routinely perform PFT before high risk non
cardio thoracic surgery

27. THANK YOU