Fariba RezaeetalabAssociate Professor,Pulmonologistrezaitalabf@mums.ac.ir

Patient related risk factors Procedure related risk factors Preoperative risk assessment

Risk reduction strategies Risk reduction strategies

Age Obesity Smoking General health status

Chronic obstructive pulmonary disease Chronic obstructive pulmonary disease (COPD)

Asthma Sleep apnea

American Society of Anesthesiologists Clalssification

Class I :There is no organic, physiological or psychiatric disturbance .The pathologic process for which the operation is to be performed is localized and is not a systemic disturbance.

Class II: Mild to moderate systemic disturbance caused either by the condition to be treated surgically or by other pathophysiological process

Class III: Severe systemic disturbance or disease from what ever cause, eventhough it may not be possible to Class III: Severe systemic disturbance or disease from what ever cause, eventhough it may not be possible to define the degree of disability with finality

Class IV: Indicate of the patient with severe systemic disorder already life threatening not always correctable by the operative procedure

Class V: the moribund patient who has little chance of survival but is submitted to the operation in desperation

Class VI : Transplantation

Morbid obesity → restrictive lung disease,↓thoracic compliance, alveolar hypoventilation

Important risk factor Smoking history of 40 pack years or more→↑risk of pulmonary complications

Smoking cessation at least 8 weeks Stop smoking decrease irritation

decrease stimulus for cough

Decrease carboxyhemoglobin and nicotine level

Improved mucocilliary function and upper Improved mucocilliary function and upper airway hypersensitivity

American Society of Anesthesiologists classification

Goldman cardiac risk index ◦ include factors from history, physical examination

and laboratory dataand laboratory data

P’t with severe COPD◦ 6 times more likely to have major postoperative

pul. Complication an absolute contraindication is NOT

apparent A careful preoperative evaluation of

patients with COPD ◦ identification of high-risk patients◦ optimizing their treatment before surgery.

Inadequate control of asthma →↑risk of postoperative complications

Well controlled, peak flow measurement of >80% of predicted or personal best →average riskaverage risk

Asthmatic patients treated with corticosteroids before surgery have a low incidence of complications

Surgical site Size of removed lung parenchyma Duration and type of anesthesia Type of neuromuscular blockade

the most important predictor of pulmonary complications

The incidence of complications is inverselyrelated to the distance of the surgical incision from the diaphragm incision from the diaphragm

The complication rates for upper abdominaland thoracic surgery are the highest (range 10% to 40%)

the most important predictor of pulmonary complications

The incidence of complications is inverselyrelated to the distance of the surgical incision from the diaphragm incision from the diaphragm

The complication rates for upper abdominaland thoracic surgery are the highest (range 10% to 40%)

Thoractomy◦ Without pulmonary disease VC ↓ to 60~70% of the pre-operative value Recovering the baseline value from one to two weeks,

even if the restrictive defect can last longer, if thoracic pain persiststhoracic pain persists

◦ With pulmonary disease The effects of thoracotomy are amplified by the

coexistence of a pulmonary disease Thoractomy → thoracic pain → ↓deep breathing,

effective coughing → atelectasis, bronchial mucous retention, worsening of gas exchangeretention, worsening of gas exchange

Video-assisted thoracoscopic surgery (VATS)◦ reduced pain, postoperative complications, release

and responses of proinflammatory cytokines, and better ventilatory function during very early postoperative period after lung resection than standard thoracotomythoracotomy◦ same or better prognosis with a lesser resection by

extended segmentectomy or wedge resection with VATS in patients with small lung cancer has been recently published

Anesthesia time of > 3.5 hours →↑incidence of pulmonary complications

in a very high risk patient→ a less ambitious, briefer procedure

a review of high risk p’t◦ rate of respiratory failure general anesthesia > epidural analgesia and light

anesthesia

it appears likely that general anesthesia leads to a higher risk of clinically important pulmonary complications than do epidural or spinal anesthesia, although further studies are required to confirm thisfurther studies are required to confirm this

Pancuronium, a long-acting neuromuscular blocker◦ a higher incidence of postoperative residual

neuromuscular blockade ◦ a higher incidence of postoperative pulmonary ◦ a higher incidence of postoperative pulmonary

complications in those patients with residual neuromuscular blockade

Resective thoracic surgery Extra-thoracic and thoracic surgery without

lung resection

Clinical evaluation◦ History & PE

Pulmonary function test◦ Spirometry & Blood gas analysis

Split lung function studies Split lung function studies Cardopulmonary exercise test

Complete history◦ Smoking, poor exercise tolerance, unexplained

dyspnea or cough◦ unrecognized chronic lung disease should be

determinedGood physical examination Good physical examination◦ directed toward evidence for obstructive lung

disease◦ decreased breath sounds, wheezes, rhonchi, or

prolonged expiratory phase

all candidates for lung resectionshould have preoperative PFT

PFTs should not be ordered routinely prior to abdominal surgery or other high risk surgeriessurgeries◦ Patients undergoing coronary bypass or upper

abdominal surgery with a history of smoking ordyspnea.◦ Patients undergoing head and neck, orthopedic,

or lower abdominal surgery with unexplaineddyspnea or pulmonary symptoms

These tests simply confirm the clinical impression of disease severity in most cases, adding little to the clinical estimation of risk

There has also been concern that There has also been concern that preoperative PFTs are overused and a source of wasted health care dollars

PFTs should not be used as the primary factor to deny surgery

the results from PFT should be interpreted in context of clinical situation and should not be the sole reason to withhold not be the sole reason to withhold necessary surgery

Most patients with abnormal spirometrywould be apparent based on history and physical examination

Two reasonable goals to use of preoperative PFTs◦ Identification of a group of patients for whom

the risk of the proposed surgery is not justified by the benefitby the benefit◦ Identification of a subset of patients at higher

risk for whom aggressive perioperative management is warranted

Spirometry◦ performed when the patient is clinically stable

and receiving maximal bronchodilator therapy◦ Risky for Pneumonectomy FEV1< 60% of the predicted value or < 2 liters DLCO< 60% of the predicted value DLCO< 60% of the predicted value MVV< 50% of the predicted value ◦ Safe lower limit for Pneumonectomy FEV1> 80% of the predicted value or > 2 liters◦ Safe lower limit for Lobectomy FEV1>1.5 litres or > 60% of the predicted value

Blood gas analysis◦ Current data do not support the use of

preoperative arterial blood gas analyses to stratify risk for postoperative pulmonary complicationscomplications◦ Hypoxemia: SaO2 < 90%◦ Hypercapnia: PaCO2 > 45mmHg not necessarily an absolute contraindication for surgery lead to a reassessment of the indication for the

proposed procedure and aggressive preoperative preparation

At-risk p’t require a closer diagnostic examination toestimate the likely post-resection pulmonary reserve

Predicting post-resection pulmonary function

Predicted postoperative FEV1 (ppoFEV1) is the most valid single test available◦ ppoFEV1 = preoperative FEV1 × (1– %functional ◦ ppoFEV1 = preoperative FEV1 × (1– %functional

tissue removed/100)◦ lung function can be calculated by counting the

number of segments removed The lungs contain 19 segments (3 right upper lobes, 2 right

middle lobes, 5 right lower lobes, 3 left upper lobes, 4 left lower lobes, 2 left lingula)

◦ Ventilation-perfusion(V/Q) scan allows detailed assessment of the functional capacity of

the lung and accurate determination of which lobes or segments contribute proportionally to ventilation and perfusion before their resection

Allows the calculation of the functional remaining parenchyma after surgery and the predicted post-parenchyma after surgery and the predicted post-resection FEV1 value

Correlations between the predicted and observed post-resection FEV1 values have proved to be good, although errors tend to underestimate postoperative function

◦ Quantitatve CT

FEV1ppo > 40%, DLco ppo > 40%◦ Widely accepted as a predictor of average risk

for complications FEV1ppo < 40%, DLco ppo < 40%◦ High risk of perioperative complications

including deathincluding death◦ FEV1ppo <1L → sputum retention◦ FEV1ppo <0.8L → preclude resection ,

dependent on a ventilator Post-operative lung function shows

borderline values → Cardiopulmonary exercise test

stress the entire cardiopulmonary and oxygen delivery system → expect the functional reserve after pulmonary resection

Maximal oxygen uptake (VO2max)◦ VO2max > 20mL/kg/min ◦ VO2max > 20mL/kg/min are not at increased risk for complications or death

◦ VO2max < 15 mL/kg/min an increased risk of peri-operative complications

◦ VO2max < 10 mL/kg/min a very high risk for post-operative complications or

death

Pre-operative strategies Intra-operative strategies Post-operative strategies

goals of preoperation pulmonary evaluation◦ identify high-risk patients in whom prophylactic

measures may reduce the risk of postoperative complications

Smoking cessation◦ As least 8 weeks before surgery◦ Counseling accompanied with nicotine

replacement or bupropion therapy improves the success rate

COPD◦ be treated aggressively to achieve their best

possible baseline function ◦ Bronchodilators, smoking cessation, antibiotics,

and chest physical therapy◦ give preoperative course of systemic steroids to ◦ give preoperative course of systemic steroids to

patients who continue to have symptoms despite bronchodilator therapy.

Asthma◦ an evaluation before surgery a review of symptoms, medication use (particularly the

use of systemic corticosteroids for longer than 2 weeks in the past 6 months), and measurement of pulmonary function.

◦ A short course of systemic corticosteroids may ◦ A short course of systemic corticosteroids may be necessary to optimize pulmonary function. ◦ For patients who have received systemic

corticosteroids during the past 6 months give 100 mg hydrocortisone every 8 hours

intravenously during the surgical period and reduce dose rapidly within 24 hours following surgery

Pre-operative antibiotics◦ Treat respiratory infection if present◦ Indiscriminate use of prophylactic antibiotics does

not lead to a reduction in pulmonary complications and should be avoided

Patient education Patient education◦ Lung expansion, deep breathing and coughing

Type of anesthesia◦ Intermediate and shorter acting agents are

preferred◦ Spinal anesthesia is safer than general

anesthesia for high-risk patients

Duration and type of surgery◦ a less ambitious, shorter procedure should be

considered in high-risk patients.◦ Because upper abdominal and thoracic operations

carry the greatest risk, a laparoscopic procedure should be preferred over an open procedure if should be preferred over an open procedure if possible.

Lung expansion maneuvers◦ Deep breathing exercises, incentive spirometry ↓postoperative pulmonary complications in high-risk

patients◦ Postoperative continuous positive airway pressure

(CPAP) (CPAP) ↓the incidence of pulmonary complications after

major abdominal surgery

Pain control◦ helps minimize pulmonary complications encouraging early ambulation, performance of lung

expansion maneuvers.◦ opioid narcotics and related medications Intrathecal: longer duration of analgesia (15-22 h)

but may be associated with respiratory depression and headaches

Epidural: an alternative to systemic analgesia

Pneumonia Bronchitis Lobar atelectasis Lobar atelectasis Respiratory failure Prolonged intubation