Fariba Rezaeetalab Associate Professor,Pulmonologist

Transcription

1 Fariba Rezaeetalab Associate Professor,Pulmonologist

2 Patient related risk factors Procedure related risk factors Preoperative risk assessment Risk reduction strategies

3 Age Obesity Smoking General health status Chronic obstructive pulmonary disease (COPD) Asthma Sleep apnea

4 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 define the degree of disability with finality it may not be possible to 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

5 Morbid obesity restrictive lung disease, thoracic compliance, alveolar hypoventilation

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

7 Smoking cessation at least 8 weeks Stop smoking decrease irritation decrease stimulus for cough

8 Decrease carboxyhemoglobin and nicotine level Improved mucocilliary function and upper Improved mucocilliary function and upper airway hypersensitivity

9 American Society of Anesthesiologists classification Goldman cardiac risk index include factors from history, physical examination and laboratory data

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11 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.

12 Inadequate control of asthma risk of postoperative complications Well controlled, peak flow measurement of >80% of predicted or personal best average risk Asthmatic patients treated with corticosteroids before surgery have a low incidence of complications

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

14 the most important predictor of pulmonary complications The incidence of complications is inversely related to the distance of the surgical incision from the diaphragm The complication rates for upper abdominal and thoracic surgery are the highest (range 10% to 40%)

15 the most important predictor of pulmonary complications The incidence of complications is inversely related to the distance of the surgical incision from the diaphragm The complication rates for upper abdominal and thoracic surgery are the highest (range 10% to 40%)

16 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 persists

17 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 exchange

18 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 thoracotomy 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

19 Anesthesia time of > 3.5 hours incidence of pulmonary complications in a very high risk patient a less ambitious, briefer procedure

20 a review of high risk p t rate of respiratory failure general anesthesia > epidural analgesia and light anesthesia

21 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 this

22 Pancuronium, a long-acting neuromuscular blocker a higher incidence of postoperative residual neuromuscular blockade a higher incidence of postoperative pulmonary complications in those patients with residual neuromuscular blockade

23 Resective thoracic surgery Extra-thoracic and thoracic surgery without lung resection

24 Clinical evaluation History & PE Pulmonary function test Spirometry & Blood gas analysis Split lung function studies Cardopulmonary exercise test

25 Complete history Smoking, poor exercise tolerance, unexplained dyspnea or cough unrecognized chronic lung disease should be determined Good physical examination directed toward evidence for obstructive lung disease decreased breath sounds, wheezes, rhonchi, or prolonged expiratory phase

26 all candidates for lung resection should have preoperative PFT PFTs should not be ordered routinely prior to abdominal surgery or other high risk surgeries Patients undergoing coronary bypass or upper abdominal surgery with a history of smoking or dyspnea. Patients undergoing head and neck, orthopedic, or lower abdominal surgery with unexplained dyspnea or pulmonary symptoms

27 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 preoperative PFTs are overused and a source of wasted health care dollars

28 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 necessary surgery Most patients with abnormal spirometry would be apparent based on history and physical examination

29 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 benefit Identification of a subset of patients at higher risk for whom aggressive perioperative management is warranted

30 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 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

31 Blood gas analysis Current data do not support the use of preoperative arterial blood gas analyses to stratify risk for postoperative pulmonary complications 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

32 At-risk p t require a closer diagnostic examination to estimate the likely post-resection pulmonary reserve

33 Predicting post-resection pulmonary function Predicted postoperative FEV1 (ppofev1) is the most valid single test available 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)

34 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 postresection FEV1 value Correlations between the predicted and observed postresection FEV1 values have proved to be good, although errors tend to underestimate postoperative function Quantitatve CT

35 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 death FEV1ppo <1L sputum retention FEV1ppo <0.8L preclude resection, dependent on a ventilator Post-operative lung function shows borderline values Cardiopulmonary exercise test

36 stress the entire cardiopulmonary and oxygen delivery system expect the functional reserve after pulmonary resection Maximal oxygen uptake (VO2max) 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

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

39 goals of preoperation pulmonary evaluation identify high-risk patients in whom prophylactic measures may reduce the risk of postoperative complications

40 Smoking cessation As least 8 weeks before surgery Counseling accompanied with nicotine replacement or bupropion therapy improves the success rate

41 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 patients who continue to have symptoms despite bronchodilator therapy.

42 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 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

43 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 Lung expansion, deep breathing and coughing

44 Type of anesthesia Intermediate and shorter acting agents are preferred Spinal anesthesia is safer than general anesthesia for high-risk patients

45 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 possible.

46 Lung expansion maneuvers Deep breathing exercises, incentive spirometry postoperative pulmonary complications in high-risk patients Postoperative continuous positive airway pressure (CPAP) the incidence of pulmonary complications after major abdominal surgery

47 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

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50 Pneumonia Bronchitis Lobar atelectasis Lobar atelectasis Respiratory failure Prolonged intubation

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