Pre-operative Pulmonary Evaluation

1. Pre-operative Pulmonary Evaluation Ri ???/VS???

3. Benefits from surgery ?? Risk of complications

4. Outline Patient related risk factors Procedure related risk factors Preoperative risk assessment Risk reduction strategies

5. Patient related risk factors Age Obesity Smoking General health status Chronic obstructive pulmonary disease (COPD) Asthma

6. Age Minor risk factor independent predictor (?) ASA risk class 3 or 4, and advanced age(>50yr) independent risk factors Surgery should not be declined in elderly patients who are otherwise acceptable surgical candidates.

8. Obesity Morbid obesity ? restrictive lung disease,? thoracic compliance, alveolar hypoventilation Not consistent 169 patients treated for acetabular fracture, obese subjects (BMI = 30) > normal weight (BMI <25) 10 series of obese gastric bypass, morbidly obese patients(3.9%)? non-obese patients.8

9. Smoking Important risk factor Smoking history of 40 pack years or more ??risk of pulmonary complications stopped smoking < 2 months : stopped for > 2 months = 4:1 (57% : 14.5%) quit smoking > 6 months : never smoked = 1:1 (11% : 11.9%)

10. General health status American Society of Anesthesiologists classification Goldman cardiac risk index include factors from history, physical examination and laboratory data

12. COPD 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.

13. Asthma 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

15. Procedure related risk factors Surgical site Size of removed lung parenchyma Duration and type of anesthesia Type of neuromuscular blockade

16. Surgical site 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%)

17. Surgical site (cont.) Upper abdomen Incisions cross the abd. muscle,? diaphragmatic motility ? ?Vital capacity Lateral thoracotomy Incision of the intercostal muscle, introduction of a pleural drain ? pleural effusion, post-op pain ? ? thoracic compliance

18. Surgical site (cont.) 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

19. Surgical site (cont.) 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

20. Surgical site (cont.) 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

21. VATS lobectomy in NSCLC at clinical stage I could well be acceptable VATS lobectomy for Stage I lung cancer, with 97.2% 8-year survival rate for Stage IA lung cancer, better than outcomes by thoracotomy VATS lobectomy for lung cancer has the benefits of less pain, shorter hospital stay, less inflammatory response and better long term functional level (extremity movement) It suggests that these procedures would be applied for patients with poor pulmonary reserve who have not been considered as candidates for pulmonary resection.

22. Surgical site (cont.) Lung biopsy through small thoracotomy Minimal incision, very small resected lung parenchyma Rare respiratory effects Few contraindications (eg. Hemodynamic instability, serious haemocoagulative alterations)

23. Surgical site (cont.) Heart-surgery usually require median sternotomy functionally better tolerated than lateral thoracotomy (due to preserves the pleural space) respiratory function is generally well preserved, except for a transitory reduction in pulmonary volumes.

24. Size of removed lung parenchyma Removal of non-functional lung Bulla may cause an improvement or at least no deterioration in lung function Bronchiectasis ?secretions and purulent exudates Benign tumor (ex. thickened pleura decortication) may allow the remaining lung to re-expand

25. Size of removed lung parenchyma (cont.) However, in most patients, thoracic surgery results in some function impairment Lobectomy shows less functional consequences than pneumonectomy

26. Size of removed lung parenchyma (cont.) Lobectomy the remaining lobes on that side rapidly expand to fill the vacant space only a modest reduction in VC, in Maximal Voluntary Ventilation (MVV) and in the DLCO occur After surgery, the adaptation of the remaining lobe may take up to three months

27. Size of removed lung parenchyma (cont.) The entity of the functional reduction depends on the removed lobe lobectomy of the right middle lobe (2 segments) has a smaller functional impact than the lobectomy of the right inferior lobe (5 segments)

28. Size of removal of removed lung parenchyma (cont.) Pneumonectomy Space remains is partly filled by mediastinal displacement and ascent of the diaphragm Pleural fluid usually collects and replaces the pneumothorax

29. Size of removed lung parenchyma (cont.) Inspite of this, ventilatory capacity after pneumonectomy may be surprisingly good If the parenchyma of the remaining lung is normal, blood gases remain in the normal range both at rest and during exertion Only pulmonary arterial pressure, which is normal at rest, may increase during exertion

30. Duration and type of anaesthesia Anesthesia time of > 3.5 hours ??incidence of pulmonary complications in a very high risk patient? a less ambitious, briefer procedure

31. Duration and type of anaesthesia (cont.) a review of high risk p’t rate of respiratory failure general anesthesia > epidural analgesia and light anesthesia

32. Duration and type of anaesthesia (cont.) The review evaluated the results of 141 trials that included 9559 p’t a reduction in risk of pulmonary complications among patients receiving neuraxial blockade (either epidural or spinal anesthesia) with or without general anesthesia, when compared to those receiving general anesthesia alone neuraxial blockade ?39% risk of pneumonia, ?59% risk of respiratory depression

33. Duration and type of anaesthesia (cont.) 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

34. Type of neuromuscular blockade 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

35. Preoperative risk assessment Resective thoracic surgery Extra-thoracic and thoracic surgery without lung resection

36. Resective thoracic surgery Clinical evaluation History & PE Pulmonary function test Spirometry & Blood gas analysis Split lung function studies Cardopulmonary exercise test

37. Clinical evaluation 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

38. Pulmonary function testing 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

39. Pulmonary function testing(cont.) 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

40. Pulmonary function testing(cont.) 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

41. Pulmonary function testing(cont.) 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

42. Pulmonary function testing(cont.) 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

43. Pulmonary function testing(cont.) 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

44. Pulmonary function testing(cont.)

45. Split lung function studies 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)

46. Split lung function studies(cont.) 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-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

47. Split lung function studies(cont.) 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

48. 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 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

49. Assessment of p’t candidate for lung resection

50. A Case of lung resection

51. Admission Chief Complaint One mass over right paratracheal area was accidentally found by Chest X-ray Diagnosis Lung cancer VATS lobectomy, RUL and LN dissection

52. Present Illness ?X?, 63-year-old woman Histories of COPD, angina, peptic ulcer and renal stone Cigarette smoking for more than 40 yrs and got COPD since youth Since 4 years ago Cough with whitish sputum and dyspnea with dizziness while suddenly standing and exercise

53. Regular follow-up and took medicine for COPD and angina every month at ???? hospital Follow up chest X ray in 96/08 Right paratracheal lesion CEA: 7.5 Body weight loss from 38 kg to 34 kg in 2 months She was admitted for further survey and managements

54. Past History Major systemic disease COPD, angina, peptic ulcer, renal stone, DM(-), HTN(-) Operation Appendectomy, C/S, hysterectomy for myoma, cataract Drug allergy: pyrine Drinking(-); Smoking(+): <1PPD for 40 yrs

55. 96/11/13 PFT FVC: 1.92L; % of predict: 93.1% FEV1: 0.78L; % of predict: 47.7% FEV1/FVC: 40.6%<60%?airflow obstruction 96/11/16 CT-guided biopsy Lung cancer, Squamous cell carcinoma 96/11/19 Bone scan: negative

56. 96/11/22 Exercise PFT VO2(ml/min/Kg):61.89% Discontinued due to weakness and dyspnea Whole body PET Solitary FDG hypermetabolic lesion at RUL 96/11/26 VATS lobectomy,RUL and LN dissection Hemodynamic calculation PVR: 749 DS/cm5

57. ICU Treatment Course 96/11/27 Cardiac echo Good LV contractility, LVEF: 84.6% TR(+): moderate with PG 25 mmHg CVP: 11~12 PAP:47/22(32)------Pulmonary Hypertension! ABP:87/52(66) After PGE1 use PVR: 491 DS/cm5 Try weaning gradually Chest tube: -10cm H2O low pressure

58. 96/11/30 Right lung pneumonia Change Cefametazon to Tazocin for pulmonary infiltration increase CRP: 8.15 Off PGE1 Remove S-G(?sheeth)

59. Risk reduction strategies Pre-operative strategies Intra-operative strategies Post-operative strategies

60. Pre-operative strategies goals of preoperation pulmonary evaluation identify high-risk patients in whom prophylactic measures may reduce the risk of postoperative complications

61. Pre-operative strategies(cont.) Smoking cessation As least 8 weeks before surgery Counseling accompanied with nicotine replacement or bupropion therapy improves the success rate

62. 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.

63. 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

64. 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

65. Intra-operative strategies Type of anesthesia Intermediate and shorter acting agents are preferred Spinal anesthesia is safer than general anesthesia for high-risk patients

66. 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.

67. Post-operative strategies 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

68. 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

70. Thanks for your listening!