Lung resection

PRE OPERATIVE LUNG FUNCTION
TESTING FOR LUNG RESECTION
DR ANUSHA CM

INTRODUCTION
Lung resection is an expanded procedure that includes
resection of the parietal and visceral pleurae,
diseased lung, ipsilateral hemi-diaphragm, ipsilateral
pericardium, and mediastinal lymph nodes
Indications
1. Malignant
• Pulmonary metastasis
• Non small cell lung carcinoma

2. Benign
• Chronic lung infection (multiple
abscesses, bronchiectasis, fungal
infection,tuberculosis)
• Traumatic lung injury
• Bronchial obstruction with destroyed lung
• Congenital lung disease

TYPES OF LUNG RESECTION
1. LOBECTOMY- Removal of one lobe
2. BILOBECTOMY- Removal of 2 or more lobes
3. PNEUMONECTOMY- Removal of whole lung
4. WEDGE RESECTION- Removal of an area of
the lung that includes part of one or more
lobes.

4. SEGMENTECTOMY- Removal of areas of the lung
along with their veins, arteries and airways.
5. SLEEVE RESECTION- Removal of the affected section
of the bronchus and any surrounding cancer in the
lobe
6. LYMPHADENECTOMY- Removal of metastatic lymph
nodes

APPROACHES
1. THORACOTOMY – incision is made around
the side of chest
2. VATS – Also called key hole surgery , done via
laparoscope connected to a fibro optic
camera

CHANGES IN PULMONARY FUNCTIONS
WITH SURGERY

PRE- OPERATIVE RISK FACTORS
1. COPD
• Incidence of postoperative pulmonary complications
in patients with COPD varies from 10% to greater
than 50%
• Complications increase significantly when the FEV1 is
below 65% of predicted

• An increase in the Closing Capacity favors
development of areas of low ventilation-to-
perfusion ratios and atelectasis
• Smokers have impaired ciliary function with
tracheobronchitis adding as contributory
factor

2. RESTRICTIVE LUNG DISEASE
• IN RLD , FRC is reduced, favoring the
formation of areas of poor ventilation and
atelectasis , also coughing and the ability to
clear respiratory secretions are impaired.

• Most commonly seen in
(1) sarcoidosis complicated by
aspergilloma and hemoptysis
(2) corrective surgery for kyphoscoliosis
(3) myasthenia gravis with associated
thymoma

3. OBSTRUCTIVE SLEEP APNEA
• Unrecognized OSA is significant, because both
anesthesia and surgery affect sleep architecture, also
use of postoperative narcotics for analgesia may
further blunt ventilatory chemosensitivity, suggesting
that postoperative respiratory morbidity is likely
higher in patients with OSA than in the general
population

• It can be used as an opportunity to screen for
OSA, the value of preoperative screening for
OSA as a means of decreasing postoperative
pulmonary complications

3. SMOKING HISTORY
• Smoking increases the risk of postoperative
respiratory complications, even among those without
COPD
• A statistically significant reduction in complications
occurs only when patients discontinue smoking for at
least 8 weeks prior to surgery

4. GENERAL STATE OF HEALTH
• Overall clinical status, as categorized by the
American Society of Anesthesiologists’ (ASA)
classification , correlates with development of
postoperative pulmonary complications.
• Specifically, an ASA classification of II or higher is
a powerful predictor of increased risk for
respiratory problems after surgery

5. AGE
• Although increased age was previously thought
to be a minor risk factor for postoperative
respiratory complications,more recent analyses
indicate that increasing age is, in fact, a
significant independent predictor, even after
accounting for comorbid conditions associated
with aging

• In a study , in patients over age 70 years who
underwent resectional lung surgery, the incidence of
postoperative pulmonary complications and hospital
stay were not increased, and survival was not
decreased
• Thus treatment decision should be individualised to
each patient

6. OBESITY
• The accumulation of fat in the chest wall, diaphragm,
and abdomen may reduce total respiratory
compliance by more than 60%—a change that is
amplified when the patient assumes the supine
position

• Spirometry shows reduction in ERV
• Areas of low ventilation relative to perfusion
and atelectasis are seen and also predisposed
to aspiration ( high gastric volume and low pH)

7. NUTRITIONAL STATUS
• The effects of malnutrition and severe starvation on
the respiratory system include a reduced ventilatory
response to hypoxia, decreased diaphragmatic
muscle function, impaired cell-mediated and
humoral immunity, and alterations in the elastic
properties of the lung

• Malnutrition are associated with expiratory
muscle weakness (despite preservation of
pulmonary function) and an increased
incidence of postoperative respiratory
complications

PREOPERATIVE EVALUATION
1. HISTORY AND EXAMINATION
• Smoking history
• History of respiratory symptoms (e.g., cough, chest
pain, dyspnea), including symptoms of sleep apnea
• Extent of pre-existing lung disease
• History of recent respiratory tract infection

2. CHEST RADIOGRAPH
• The preoperative chest radiograph is usually
unrevealing if risk factors and abnormal physical
findings are absent.
• A preoperative chest radiograph is indicated when
there are new or unexplained symptoms or signs,
when there is a history of underlying lung disease
and no recent chest radiograph, or when thoracic
surgery is planned

3. ARTERIAL BLOOD GAS ANALYSIS
• Elevated PaCO2 is associated with an increased
incidence of postoperative respiratory morbidity in
patients with significant chronic lung disease
• The determination serves as a basis for comparison
with subsequent intra- and postoperative
measurements

POST OPERATIVE COMPLICATIONS
• Acute CO2 retention (PaCO2 > 45 mm Hg)
• Prolonged mechanical ventilation (> 48 h)
• Infections (bronchitis & pneumonia)
• Atelectasis (necessitating bronchoscopy)
• Bronchospasm
• Exacerbation of the underlying chronic lung
disease
• Pulmonary embolism
• Symptomatic cardiac arrhythmias
• Myocardial infarction
• Death

EVALUATION FOR LUNG RESECTION
1.PULMONARY FUNCTION TESTING
2. PREDICTION OF POST OPERATIVE FEV1 OR
DLCO
3. CARDIO PULMONARY EXERCISE TESTING

1.PULMONARY FUNCTION TESTING
• To assess the risk of post operative
complications , spirometry is needed to
evaluate for airway obstruction and the
degree of restriction (as assessed by lung
volumes)

Indications for pre op pulmonary function
testing
• Presence of cough or
• Unexplained dyspnea
• History of chronic lung disease
• History of cigarette smoking (>20 packyears),
• Planned lung resection

• Studies dating back to the 1950s have shown
that the risk of postoperative respiratory
complications following pneumonectomy
increases significantly when the FEV1 is less
than 2 L or 80% of predicted normal, or when
the maximal voluntary ventilation (MVV) is
less than 50% of predicted.

• For a lobectomy, an FEV1 of 1.5 L appears to
be the critical threshold.
• The diffusion capacity for carbon monoxide
(DLCO) has also been identified as a predictor
of postoperative complications.

• Increased risk is associated with a DLCO of less
than 60% to 80% of predicted and appears to be
independent from FEV1 as a predictor of
complications, morbidity, and death.
• Therefore ,predictive postoperative lung function
should be estimated for patients with an FEV1 or
DLCO less than 80% of predicted.

SPLIT FUNCTION STUDIES
• The estimation of post operative lung function is
based on hypothesis that each segment of resected
lung contributes to a fixed percentage of lung
function
• Juhl and Frost compared pre and post operative lung
function and suggested that each lung segment
resected would decrease lung function by 5.26%

• According to BTS guidelines, estimated FEV1 is
calculated by
Estimated post op FEV1+ pre op FEV1 X [19-a)-b)] / 19 –a
Where a and b are no of segments, respectively to be resected
• Guidelines suggest that estimated post op FEV1 >
40% is above the threshold of avg risk for
complication after lung resection

2. PREDICTION OF POST OPERATIVE
FEV1 OR DLCO
Ventilation–perfusion lung scans measure the relative blood flow
or ventilation to one lung or lung region and can be used to
predict postoperative FEV1 or DLCO using the following equation
An alternative approach to estimating the predicted postoperative
pulmonary function involves a calculation based on the number
segments of the lung (10 on the right and nine on the left)

• For right upper lobectomy (3 segments) in a patient
with a preoperative FEV1 of 1.6 litre which is 80% of
predicted normal, the ppo-FEV will be 1.6x16/19 =
1.35 litre, and the ppo-FEV1% will be 80%x 16/19 =
67%.
• The same form of ppo calculation may be applied to
the measured DLCO or the DLCO as a percentage of
the predicted normal value.

• A number of studies have demonstrated that the
perioperative risk for lung resection increases
significantly when the predicted postoperative FEV1
or DLCO has <40% of predicted
• Therefore, a predicted postoperative FEV1 or DLCO
≥40% predicted has been proposed as useful criteria
for undertaking “safe” pulmonary resection

3. CARDIO PULMONARY EXERCISE
TESTING
• Cardiopulmonary exercise testing (CPET) is a non-
invasive technique that involves sub maximal and
maximal treadmill or bicycle exercise with
continuous ECG monitoring and breath-by-breath
determination of oxygen uptake and carbon dioxide
output, and spirometry.

• Measurement of maximal oxygen consumption
(VO2max) during cardiopulmonary exercise testing
to be useful in predicting postoperative morbidity
and mortality
• Specifically, a V2Omax of less than 15 to 20
mL/kg/min is associated with an increased incidence
of postoperative complications.

• The risk for perioperative complications has been reported to
be higher with lower measured VO2max
• • VO2 max > 20 ml/kg/min or > 75% predicted: - can safely
safely undergo the planned resection (up to pneumonectomy)
• VO2 max between 10-15 ml/kg/min or between 35%- 75%
predicted: - indicates an increased risk of perioperative death
compared with higher values of VO2 max.
• VO2 max of < 10% predicted: - very high risk for
postoperative death - generally regarded as a contraindication
to major anatomic resections

• Other alternative tests include stair climbing
and a walking test, can be used to assess a
patient’s fitness for lung resection.

STAIR CLIMBING TEST
• Can used be as a first-line functional screening
test to select those patients that can undergo
safely to operation (height of ascent > 22 m)
• Demonstration of a patient’s ability to climb five
flights of stairs predicts V2Omax >20 mL/kg/min
• Patients who are unable to climb one flight of
stairs have a V2Omax <10 mL/kg/min

• Limitation of test : lack of standardization - the
duration of stair climbing, the speed of ascent, the
number of steps per flight, the height of each step,
and the criteria for stopping the test have varied
from study to study.

• An ability to climb three flights of stairs reliably
identifies patients who are likely to do well after a
lobectomy, despite having a predicted postoperative
FEV1 or DLCO that is <40% of predicted.
• The shuttle walk and 6-minute walk tests have also
been used as alternatives to cardiopulmonary
exercise testing.

• For the shuttle walk, the patient walks back and
forth over a distance of 25 m at a progressively faster
rate.
• Inability to complete 25 shuttles approximates a <10
mL/kg/min.
• A 6-minute walk distance >1000 ft has been reported
as predictive of successful surgical outcome

• Cardiopulmonary exercise testing is used to
further assess the operability of patients of who
would be at high risk for surgery based on
determination of predicted postoperative
pulmonary function

SEQUENTIAL APPROACH FOR EVALUATION OF LUNG RESECTION

• The approach is adapted from recommendations of
the American College of Chest Physicians (ACCP)
• The approach is predicated on determining the
patient’s operability for pneumonectomy, should this
procedure be deemed necessary at the time of
surgery (e.g., to permit complete removal of a tumor
or to deal with an unanticipated intraoperative
complication)

PREOPERATIVE PULMONARY
PREPARATION
• Pulmonary function in patients with obstructive
airway disease should be optimized.
• Therapy includes any or all of the following:
bronchodilators, corticosteroids, antibiotics (when
there is evidence of infection), and chest
physiotherapy (if excessive secretions are present).

• When possible, these interventions should be
implemented 48 to 72 hours prior to surgery.
• Ideally, for at least 8 weeks prior to surgery, smoking
should be discontinued.

• Program of inspiratory muscle training for at least 2
weeks prior to surgery may reduce the incidence of
postoperative pulmonary complications in patients at
high risk for their development.
• Finally, patient education on the importance of
postoperative coughing and pain control, proper use
of an incentive spirometer, and deep breathing
exercises should take place preoperatively

SUMMARY
• All patients being considered for lung resection should
undergo preoperative physiologic evaluation.
• Pulmonary function testing using spirometry (FEV1 ), DLCO
and VO2 max help predict the risk of post-operative
complications and mortality.
• Predicting postoperative lung function using the proportion of
lung segments to be resected, perfusion scanning, or other
methods is important for assessing surgical risk.
• Current international guidelines provide algorithms for
preoperative risk assessment.

Lung resection

More Related Content

What's hot (20)

Similar to Lung resection (20)

More from Anusha Jahagirdar (12)

Recently uploaded (20)

Lung resection

Editor's Notes