PREPARATIVE ASSESSMENT OF PATIENTS UNDERGOING THORACIC SURGERIES.pptx

Preoperative Assessment And Preparations of Patient Undergoing Thoracic Surgeries
To identify patients at risk – History, physical examination.
Stratify the extent of risk, determine the need for optimization, preoperative consultation, further test.
Change in medical therapy to minimize the risk of perioperative complications.
Plan timing of surgeries, alternative strategies and optimal management.
To organize and standardize the approach to preoperative evaluation
Two phases:
Initial (clinic) assessment and
Day-of admission assessment

Pre-thoracotomy assessment naturally involves
Past history
Allergies
Medications
Upper airway
Respiratory complaints : May assist clinicians in identifying pulmonary conditions
Social habits, such as smoking, that could increase the risk for postoperative pulmonary complications.
Modifying risks in selected groups of patients: Reduces PPC
Detailed history of the patient’s quality of life
Baseline simple spirometry to be done preoperatively.
Respiratory function can be divided into three independent areas:
Respiratory mechanics,
Gas exchange
Cardiopulmonary interaction (i.e., exercise capacity).
Many tests of respiratory mechanics and volumes show correlation with postthoracotomy outcome: forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), maximal voluntary ventilation (MVV), residual volume/total lung capacity ratio (RV/TLC), and so on (see Chapter 13 on pulmonary function testing).
Ability of the lung to exchange oxygen and carbon dioxide between the pulmonary vascular bed and the alveoli.
Useful test of the gas exchange capacity of the lung is the diffusing capacity for carbon monoxide (DLCO).
ppoDLCO less than 40% correlates with both increased respiratory and cardiac
DLCO less than 20% had an unacceptably high perioperative mortality rate
the ability to climb two flights of stairs without stopping is a minimum to be considered for pulmonary resection evaluation.
Studies have shown moderate correlation with adverse cardiac events at intermediate functional capacity

VO2max can be estimated from the 6MWT distance in meters divided by 30 (i.e., 6MWT of 450 m: estimated VO2max = 450/30 = 15 mL/kg/min)
Shuttle walking test: A distance of less 250 meters correlates with a VO2max of less than 10 mL/kg/min.
Exercise-oximetry : Patients with a decrease of blood oxygen saturation (SpO2) greater than 4% during exercise are at increased risk.
Prediction of post resection pulmonary function can be further refined by assessment of the preoperative contribution of the lung or lobe to be resected using ventilation-perfusion (V/Q) lung scanning.
Lung region to be resected is nonfunctioning, the prediction of postoperative function can be modified accordingly
V/Q scanning should be considered for any pneumonectomy patient who has a preoperative FEV1 and/or DLCO less than 80%.
Mild sedation such as intravenous short-acting benzodiazepine is often given
In patients with copious

1. Preoperative Assessment And Preparations of Patient Undergoing Thoracic Surgeries Presenter Moderator Pawan Rai Lt . Col. Dr. Thaneshwar Rijal Anesthesia resident Consultant Anesthesiologist Dept. Of Anaesthesiology Dept . Of Anaesthesiology NAIHS NAIHS Date: 2082/05/05

2. Evolution of thoracic anesthesia Delayed 50 years after introduction of ether anesthesia due to: Problem of gas exchange with open thorax Problem of lung soiling In the early 1900s, New Orleans surgeon Matas , advocated positive-pressure ventilation and a primitive form of endotracheal ventilation, which had been demonstrated to be safe in animal experiments, for thoracic anesthesia. 8/17/2025 2

3. Indications Diagnostic Pleural biopsy Therapeutic Decortication Lobectomy Segmentectomy Pneumonectomy 8/17/2025 3

4. Goals of Preoperative Evaluation To identify patients at risk – History, physical examination . Stratify the extent of risk, determine the need for optimization , preoperative consultation, further test . Change in medical therapy to minimize the risk of perioperative complications . Plan timing of surgeries, alternative strategies and optimal management . 4 8/17/2025

5. Goals of Preoperative Evaluation Communication between anesthesiologist , surgeons and other consultants Plan the mode of anesthesia appropriate to the cardiac and pulmonary stress. 5 8/17/2025

6. Preoperative assessment To organize and standardize the approach to preoperative evaluation Two phases : I nitial (clinic) assessment and D ay-of admission assessment Pre-thoracotomy assessment naturally involves P ast history Allergies Medications U pper airway 8/17/2025 6

7. History and Physical E xamination Respiratory complaints : May assist clinicians in identifying pulmonary conditions Social habits, such as smoking, that could increase the risk for postoperative pulmonary complications. Modifying risks in selected groups of patients: Reduces PPC 8/17/2025 7

8. Assessment of Respiratory F unction D etailed history of the patient’s quality of life B aseline simple spirometry to be done preoperatively . R espiratory function can be divided into three independent areas: R espiratory mechanics , G as exchange C ardiopulmonary interaction (i.e., exercise capacity). 8/17/2025 8

9. Respiratory mechanics U seful to express these as a percent of predicted volumes corrected for age, sex, and height (e.g., FEV1 %). M ost valid single test for post thoracotomy respiratory complications is the predicted by ppoFEV1 % ppoFEV1 % = preoperative FEV1 %× (1 − % functional lung tissue removed/100) Patients with a ppoFEV1 greater than 40% are at low risk for post resection respiratory complications 8/17/2025 9

10. Lung Parenchymal Function A bility of the lung to exchange oxygen and carbon dioxide between the pulmonary vascular bed and the alveoli. U seful test of the gas exchange capacity of the lung is the diffusing capacity for carbon monoxide (DLCO). ppoDLCO less than 40% correlates with both increased respiratory and cardiac DLCO less than 20% had an unacceptably high perioperative mortality rate 8/17/2025 10

11. Functional Capacity Quantified using the metabolic equivalent of task (MET), One MET is approximately the rate of oxygen consumption 40 yr old 70 kg man at rest - 3.5 mL/kg/min 3 categories Poor - METs <4 Intermediate - METs 4-10 Excellent - METs > 10 11 8/17/2025

12. Functional Capacity 12 8/17/2025

13. Other Exercise Test VO2max can be estimated from the 6MWT distance in meters divided by 30 (i.e., 6MWT of 450 m: estimated VO2max = 450/30 = 15 mL/kg/min ) Shuttle walking test : A distance of less 250 meters correlates with a VO2max of less than 10 mL/kg/min . Exercise- oximetry : P atients with a decrease of blood oxygen saturation (SpO2) greater than 4% during exercise are at increased risk. 8/17/2025 13

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15. Ventilation perfusion scintigraphy Prediction of post resection pulmonary function can be further refined by assessment of the preoperative contribution of the lung or lobe to be resected using ventilation-perfusion (V/Q) lung scanning. Lung region to be resected is nonfunctioning, the prediction of postoperative function can be modified accordingly V/Q scanning should be considered for any pneumonectomy patient who has a preoperative FEV1 and/or DLCO less than 80%. 8/17/2025 15

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17. Perioperative Pulmonary Risk Pre-existing pulmonary diseases Workup and care to reduce postoperative pulmonary complications Inadequate optimization develop PPCs – increased morbidity and mortality 17 8/17/2025

18. Risk Factors For PPCs – Patient Factors Comorbidities : COPD, Asthma Age Inhaled tobacco use Pulmonary HTN Moderate to severe OSA Nutrition status 18 8/17/2025

19. Risk factors for PPCs – Intraoperative Factors Surgical site (thoracic or abdominal ) Duration of surgery General anesthesia Long acting muscle relaxants Emergency surgery Blood product transfusion 19 8/17/2025

20. Risk factors for PPCs – Laboratory Tests Albumin level < 35 g/L Abnormal chest radiograph BUN > 7.5 20 8/17/2025

21. Cardiovascular Assessment Cardiac complications are the second most common cause of perioperative morbidity and mortality in the thoracic surgical population Ischemia Arrhythmia Congestive Heart failure Pulmonary Hypertension 8/17/2025 21

22. 22 Revised Cardiac Risk Index Risk Factors Points High-risk surgery ( Intrathoracic pneumonectomy lobectomy ) 1 History of ischemic heart disease 1 History of congestive heart failure 1 History of cerebrovascular disease 1 Diabetes mellitus requiring insulin 1 Creatinine > 2.0 mg/dl 1 8/17/2025

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26. Smoking cessation 8 weeks effective to decrease PPC (21-41%) and improve endobronchial ciliary function 6 weeks restores hepatic enzymes and immune function 12-24 hours decrease carboxyhemoglobin levels Encourage to quit whatever duration is available 26 8/17/2025

27. Asthma Well controlled and no infection – no specific indication PEFR Normal: 200-600 L/min >80%: Good control 50-80%: Additional treatment may be necessary <50%: Acute asthma attack Chest X-ray Spirometry: Reduced FEV1/FVC ABG 27 8/17/2025

28. Asthma Bronchodilators, steroids and antibiotics continued Prophylactic beta 2 agonist FEV1 < 80%: Steroids perioperatively Oral prednisolone 40-60 mg/day IV hydrocortisone 100 mg/8 hours Antibiotics if pulmonary infection Acute exacerbation : Postpone elective surgery until control 28 8/17/2025

29. COPD Severity by spirometry, ECG, Echocardiography, ABG Exacerbation: postpone elective surgery Inhalers and long term medications continued Pulmonary infections identified and treated Chest physiotherapy and postural drainage Optimize cardiac function in long standing cases 29 8/17/2025

30. Obstructive Sleep Apnea Screen using STOP-BANG questionnaire Sleep studies Echocardiography Continue CPAP 30 8/17/2025

31. Reduction of PPCs Preoperative respiratory training Incentive spirometry Deep breathing exercises Physiotherapy Inspiratory muscle training CPAP Preoperative cardiopulmonary exercise 31 8/17/2025

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33. Extubation Plan According To Predicted Postoperative FEV1 8/17/2025 33

34. Premedication Mild sedation such as intravenous short-acting benzodiazepine is often given In patients with copious secretions, an antisialagogue (e.g., glycopyrrolate) is useful to facilitate fiberoptic bronchoscopy for positioning of a double-lumen tube 8/17/2025 34

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37. References Miller’s Anesthesia 10 th edition Barash et al. Clinical Anesthesia 8 th edition 37 8/17/2025

38. Thank You 8/17/2025 38