Mod XI: THORACIC SURIGICAL PROCEDURES

Question 1

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

Major cause of morbidity and mortality in this patient population

Answer 1

Pulmonary complications

None of the complications can be predicted by pulmonary function studies

Research findings are limted in their ability to predict specific findings

Atelectasis, pneumonia, and respiratory failure occur in 15-20% of patients

Question 2

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

Lung surgeries are performed on a wide variety of pts including. Morbidly obese, end-stage COPD, advanced age (No maximal age cutoff for pulmonary surgical candidates) - What makes this possible?

Answer 2

Advances in surgical techniques, including the use of Video Assited Thoracospic Surgery (VATS)

VATS helped decrease incidence of post-op complications

Question 3

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

Diagnostic procedures

Answer 3

Bronchoscopy, mediastinoscopy, open-lung biopsy

Question 4

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

Plethora of indications for thoracic surgery

Answer 4

Thoracic malignancies

Chest trauma

Esophageal disease

Mediastinal tumors

Many procedures performed thoracoscopically

Question 5

PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES

Answer 5

EKG

^{To assess for Ischemia, RVH}

Echocardiogram

^{Assess for RVH, pulmonary HTN, ischemia}

Chest radiograph

^{Findings indicative of COPD: hyperinflation, increased AP diameter, diaphragmatic flattening}

^{Assess for tumor infringement on vascular structures, CHF, or pneumothorax}

Ventilation-Perfusion Assessment

^{Great tool for the prediction of postresection pulmonary function}

^{Should be considered for any patient who is to undergo pneumonectomy}

^{Removal of the diseased portion of the lung may not decrease overall lung function, but may actually improve it}

Question 6

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

EKG

Answer 6

To assess for Ischemia, RVH

Question 7

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

Echocardiogram

Answer 7

Assess for RVH, pulmonary HTN, ischemia

Question 8

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

Chest radiograph

Answer 8

Findings indicative of COPD: hyperinflation, increased AP diameter, diaphragmatic flattening

Assess for tumor infringement on vascular structures, CHF, or pneumothorax

Question 9

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

Ventilation-Perfusion Assessment

Answer 9

Great tool for the prediction of postresection pulmonary function

Should be considered for any patient who is to undergo pneumonectomy

Removal of the diseased portion of the lung may not decrease overall lung function, but may actually improve it

Question 10

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

Remember that extent of pulmonary surgery correlates inversely with the intraoperative PaO2 - Between Pneumonectomy, Lobectomy and Segmentectomy, the pt undergoing which thoracic surgery will have a higher PaO2? why?

Answer 10

PaO2 higher in pneumonectomy > lobectomy > segmentectomy

This is said to be related to the amount of perfusion into the diseased lung, as perfusion and thus shunting during OLV will be diminished with the higher amount of the lung that is diseased

The more diseased the lung, the less amount of lung tissue partaking in perfusion. The amount of shunting that will occur is dependent on the perfusion. If perfusion is low, shunting will also be low and one lung ventilation may not cause as much hypoxemia as compared to a lung with less disease and more perfusion.

If perfusion is low, shunting will be less. If perfusion is higher, shunting will be greater. Shunting = BAD, but perfusion is good.

Question 11

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

All patients to undergo thoracic surgery should have basic Pulmonary function testing performed - No single pulm function measurement provides an averall risk assessment - So a multi-modal approach should be taken, and the approach should consider

Answer 11

Respiratory mechanics

Gas exchange

Cardiopulmonary reserve

Question 12

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

What’s the single Most valid test for predicting post-thoracotomy respiratory complications?

Answer 12

Predicted Postoperative FEV1 % (ppoFEV1)

aka (respiratory mechanics)

When compared to FEV1, FVC, MVV, RV/TLC

Question 13

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

The general cut-off value for predicting increased risk is a Predicted Postoperative FEV1 % values of:

Answer 13

Postoperative FEV1 % values < 40% => Increased risk for postresection complications,

Postoperative FEV1 % values <30% => high risk

Question 14

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

Measurement of gas exchange that Deals with actual gas exchange at the alveolar/capillary level

Answer 14

Lung Parenchymal Function

Question 15

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

Historically, an arterial blood gas was used to assess the gas exchange capacity of the lungs - Why is arterial blood gas no longer used to assess the gas exchange capacity of the lungs?

Answer 15

Research has found that cancer ressections have been successfully performed in pts who did not meet the arterial blood gas cutoff criteria

Question 16

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

Since the arterial blood gas is no longer used to assess the gas exchange capacity of the lungs, which is now considered the most useful test for of the gas exchange capacity of the lungs

Answer 16

The Diffusing Capacity of the Lung for Carbon Monoxide (DLCO)

DLCO correlates with total functioning surface area of the alveolar to capillary interface

Measures the efficiency of the gas transfer characteristics of the lungs

Values <40% = increased risk

Question 17

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

The communication between the respiratory and the cardiovascular systems is also known as:

Answer 17

Cardiopulmonary Reserve

•May be considered the most important assessment of respiratory function

Question 18

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

Which is considered the “gold Standard” assessment for Cardiopulmonary function?

Answer 18

Cardiopulmonary exercise testing, with

Maximal Oxygen Consumption (VO2max) being the most useful predictor of post-thoracotomy outcome

Question 19

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

Which component of Cardiopulmonary exercise testing is the the most useful predictor of post-thoracotomy outcome

Answer 19

Maximal Oxygen Consumption (VO2max)

Question 20

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

Risk assessment - Which VO2max values are associated with increased mortality?

Answer 20

High risk = VO2max < 15 mL/kg/min

Low risk = VO2max > 20 mL/kg/min

Question 21

_{PREOPERATIVE EVALUATION FOR THORACIC PROCEDURES}

Complete laboratory exercise testing is expensive - Alternatives to it include:

Answer 21

The distance COPD patient can walk during 6-minute test

^{That distance in meters divided by 30 correlates with the maximum oxygen consumption mL/kg/min VO2max}

^{Patient unable to walk 450 meters= VO2max = 15mL/kg/min}

Ability to climb five flights of stairs

^{Ability to climb five flights of stairs correlates with VO2max >20 mL/kg/min}

^{Ability to climb 2 flights of stairs correlates with VO2max 12 mL/kg/min}

Question 22

_{OTHER PREOPERATIVE CONSIDERATIONS}

Routine screening of Ischemia for lung ressection not cost-effective - Noninvasive testing is warranted for patients with

Answer 22

Clinical predictors of myocardial risk

Question 23

_{OTHER PREOPERATIVE CONSIDERATIONS}

Optimization for ischemia prior to surgery includes:

Answer 23

Coronary angioplasty

CABG before or during lung resection

Medical management

Question 24

_{OTHER PREOPERATIVE CONSIDERATIONS}

Delay of lung resection for how long after myocardial infarction, bare metal stenting, drug-eluting stenting

Answer 24

4-6 weeks after myocardial infarction,

4-6 weeks after bare metal stenting,

12 months after drug-eluting stenting

Question 25

_{OTHER PREOPERATIVE CONSIDERATIONS}

Renal dysfunction - Significant increases in serum creatinine associated with

Answer 25

Prolonged length of stay

Was previously correlated with a high mortality rate

Studies now show that they are a/w prolonged stay, but not necesseraly high mortality

Significant increases in serum creatinine associated with prolonged length of stay

Question 26

_{OTHER PREOPERATIVE CONSIDERATIONS}

Pulmonary complications are decreased in patients who cease smoking for

Answer 26

more than 4 weeks before surgery

Question 27

_{OTHER PREOPERATIVE CONSIDERATIONS}

Smoking: concentrations of which hemoglogin varriant is decrease if smoking stopped > 12 hours prior to surgery

Answer 27

Carboxyhemoglobin

Question 28

_{INTRAOPERATIVE MONITORING FOR THROACIC SURGERY}

Goal if monitoring is:

Answer 28

To quickly recognize sudden and severe changes in ventilation and hemodynamics

Question 29

_{INTRAOPERATIVE MONITORING FOR THROACIC SURGERY}

EKG

Answer 29

Five lead EKG with precordial lead in V5 position should be used

The V5 precodial position is the most sensitive site for ischemia identification

However, depending on the side of the surgery and the position of the pt, this lead may not be able to placed correctly in the correct position

Question 30

_{INTRAOPERATIVE MONITORING FOR THROACIC SURGERY}

Arterial pressure monitoring

Answer 30

Recommended

Preferrably on the opposite side of the surgical site

Because of the lateral decubitus position, placing the a-line in the non dependent arm can result in falsely low BPs

The arterial line should be placed in the dependent side

The NIBP cuff should be place on the non-dpendent side

Question 31

_{INTRAOPERATIVE MONITORING FOR THROACIC SURGERY}

CVP monitoring

Answer 31

May not be indicated in all pts

Should be considered in pts where a large blood loss is suscpected

Question 32

_{INTRAOPERATIVE MONITORING FOR THROACIC SURGERY}

Pulmonary artery catheters

Answer 32

Typically not placed ( - > +)

If one is placed, use caution with interpretation of these numbers

Numbers may be incorrect with the pt in the lateral position

Also potential that the OLV will change the compliance of the pul vessels, which will make the wedge pressure an inaccurate assessment of LV pressure

Question 33

_{INTRAOPERATIVE MONITORING FOR THROACIC SURGERY}

Fiberoptic bronchoscopy

Answer 33

Should be present at all times

Used to place DLT

Will be needed for any repositioning or to confirm placement if OLV cannot be maimtained