Thoracic surgery anesthesia

thorax surgery

1. Thoracis anaesthesia zikrullah

2. Thoracis surgery presents with what unique set of physiologic problems ??

3. THORACIC ANAESTHESIA 1)Lateral decubitus position 2)The open pneumothorax 3)One lung ventilation

4. What happens to lung mechanics during lateral decubitus position? Awake state? After induction of anesthesia?

5. AWAKE STATE: V/Q: Preserved Dependent lung: More perfused Receives more ventilation Contraction of hemidiaphragm more efficient More favourable part of compliance curve

6. V/Q : mismatch and hypoxia Induction of G.A: FRC & moves lower lung( perfused) to less compliant part of the compliance curve PPV favors the upper lung (Compliant) Neuromuscular blockade: abdominal contents rise up against dependent hemidiaphragm Rigid bean bag INDUCTION AND PPV

7. What happens during open pneumothorax?

8. . The Open Pneumothorax : The lungs are kept expanded by the negative pleural pressure .When chest is opened the – ve pleural pressure is lost and the lung is collapsed Spontaneous ventilation with open pneumothorax in the lateral position results in paradoxical respiration & mediastinal shift

9. Paradoxical respiration : During spont ventilation To and fro gas flow between dependent and non dependent lung

10. PARADOXICAL RESPIRATION

11. Mediastinal shift: During spont ventilation Downward shift of mediastinum during inspiration Upward shift during expiration

12. MEDIASTINAL SHIFT

13. Concerns during one lung ventilation ?

14. 3. One Lung Ventilation: Intentional collapse of the lung on the operative side greatly facilitates most thoracic procedures but complicates anesthetic management The collapsed lung continues to be perfused and no longer ventilated

15. So the patient develops RT to LT intrapulmonary shunt hypoxia Widens alveolar to arterial gradient hypoxia

16. Protective mechanism ?

17. Hypoxic pulmonary vasoconstriction Factors inhibiting: Pulmonary artery pressure: very high or low Hypocapnia Mixed venous oxygen : very high or low Vasodilators Pulmonary infection Inhalational anesthetic

18. Technique of one lung ventilation?

19. Techniques for one lung ventilation: Use of double lumen BT Use of single lumen ET + bronchial blocker Use of single lumen EBT Double lumen endobronchial tube is often used

20. Indication of lung ventilation?

21. Indications for one lung ventilation: -CONFINED INFECTION TO ONE LUNG -CONFINED BLEEDING TO ONE LUNG -SEPARATE LUNG VENTILATION: *large cyst or bulla *BPF * tracheobron . disruption PATIENT RELATED: -LUNG RESECTION: * pneumonectomy * lobectomy *segmental resection -THORACOSCOPY -ANT. APPROACH TO THORACIC SPINE -ESOPHAGEAL SURGERY -B.A. LAVAGE PROCEDURE RELATED:

22. Absolute indication for OLV Isolation of one lung from the other to avoid spillage or contamination Infection Massive hemorrhage Control of the distribution of ventilation Bronchopleural / - cutaneous fistula Surgical opening of a major conducting airway giant unilateral lung cyst or bulla Tracheobronchial tree disruption Life-threatening hypoxemia due to unilateral lung disease

23. Unilateral bronchopulmonary lavage VAT

24. Relative indication Surgical exposure ( high priority) Thoracic aortic aneurysm Pneumonectomy Upper lobectomy Mediastinal exposure Thoracoscopy Surgical exposure ( Intermediate priority ) Middle and lower lobectomies and subsegmental resections Esophageal surgery Thoracic spine procedure Minimal invasive cardiac surgery .

25. Postcardiopulmonary bypass status after removal of totally occluding chronic unilateral pulmonary emboli ( Low priority )

26. Types of DLT? Advantage/disadvantage?

27. THORACIC ANESTHESIA Double lumen endobronchial tubes: Carinal hook Bronchus Name YES LEFT CARLENS NO LEFT -RIGHT ROBERT-SHAW YES RIGHT WHITE

28. Advantage: Can suction lungs independently Quality of suctioning better Can apply CPAP to nonventilated lung Disadvantage: Difficult to insert. Needs change of tube if postoperative ventilation is considered Needs determination of appropriate size Potential for tracheobronchial injury

29. How is the size of the DLT determined for each patient?

30. An ideally placed DLT should pass easily through the glottis and should enter the intended main bronchus without causing trauma Single-use PVC DLTs : 26 F, 28 F, 32 F, 35 F, 37 F, 39 F, 41 F 35 F and 37 F - small and large females 39 F and 41 F for small and large males

31. Why are left sided DLTs preferred over right?

32. The right upper lobe bronchus takes off from the right main bronchus 0.5 to 1 cm below the carina When right sided DLT is placed, there are high chances that the right upper lobe bronchus may be occluded Left mainstem bronchus is much longer than the right one (50 mm as compared to 20 mm) Margin of safety while positioning a left sided DLT is more

33. Describe the pre-anaesthetic evaluation of a patient posted for lung resection surgery ?

34. ƒDetailed medical history : coexisting disease Optimal treatment and control of associated medical conditions Patient’s functional capacity should be assessed History of smoking, symptoms suggestive of COPD elicited Preoperative cardiologic evaluation Airway evaluation Patients may receive chemotherapy preoperatively, and should be evaluated for chemotherapy related toxicity

35. Investigations?

36. Investigations CBC : Polycythemia - COPD or leucocytosis - active pulmonary infection Sputum cultures and sensitivity to guide appropriate antibiotic therapy Renal function test Liver function test X-ray Chest : tracheal deviation or obstruction, mediastinal mass, superior vena cava syndrome, pleural effusions, consolidation

37. Pulmonary function tests : obstructive or restrictive abnormalities, to assess responsiveness to bronchodilators and to confirm suitability for resection ECG : For signs of left or right heart dysfunction TTE : to rule out pulmonary hypertension Further cardiopulmonary testing may be indicate if warranted by the history/above investigations

38. Describe the 3 legged stool test of prethoracotomy respiratory assessment ?

39. Predicted post operative FEV1? Importance ?

40. Preoperative optimization?

41. THORACIC ANESTHESIA Preoperative management Result Measures HbCO2 decreases in 12-24h so more O2 is available Cessation of smoking Select antibiotics according to culture and sensitivity Treat pulmonary infections Beta-2 agonists Treat bronchospasm Hydration and chest percussion Thin and mobilize secretions

42. Preparation? Monitoring?

43. THORACIC ANESTHESIA Preparation: Apart from basic airway management Multiple single and double tubes should be available fiberoptic bronchoscope should be available Tube exchanger Cpap delivery system,bronchodilator Thoracic epidural catheter

44. THORACIC ANESTHESIA 2) Venous access: At least 2 large iv canula ( 14-16 g) is mandatory CV catheter, blood warmer ,rapid infusion device are desired if blood loss is anticipated

45. 3) Monitoring: ECG pulse oximetry Capnography NIBP Temperature Urinary catheterization Arterial cannula CVP monitoring PAC is indicated in LT ventricle dysfunction Periodic ABG

46. Induction? Maintenance?

47. GA with controlled ventilation with thoracic epidural analgesia IV induction with propofol or thiopentone Propofol : preferred since many of these patients will have reactive airways and use of thiopentone and tracheal instrumentation in light plane can lead to bronchospasm NDMR can be used

48. Maintenance : halogenated agent + opiod Delivered in an oxygen/air or oxygen/nitrous oxide mix During one-lung ventilation, anaesthesia can be maintained intravenously with propofol and an air/oxygen mix

49. What is management of hypoxemia during one lung ventilation?

50. For sudden or severe desaturation: Convert to two-lung ventilation For gradual desaturation: 1. Increase FiO2 to 1.0 2. The position of DLT should be rechecked using a fiberoptic bronchoscope. 3. The hemodynamic status of the patient should be optimized 4. Recruitment of the ventilated lung

51. 5. PEEP of 5-10 cm H2O: the dependent lung 6. CPAP of 1-2 cm H2O: to the nondependent lung, after a recruitment maneuver 7. Intermittent two-lung ventilation. 8. Partial ventilation of the non-ventilated lung using either low flow oxygen insufflations or high frequency ventilation 9. If a pneumonectomy is being performed, ligation of the pulmonary artery : completely eliminate the shunt.

52. Fluid management in these patients?

53. Fluid restriction is generally advocated in lung resections. The reasons for this are: Third spacing is not excessive in lung surgeries The dependent lung : high capillary hydrostatic pressures Postoperative pulmonary edema Surgery may impair lymphatic drainage. It is recommended that the total positive fluid balance in the first 24 hours should not exceed 20 mL/kg

54. Lower lung syndrome?

55. Excessive fluid administration may promote this syndrome i.e gravity dependent transudation of fluid into the dependent lung

56. What about mechanical ventilation post op?

57. Most patients are extubated early to reduce the risk of pulmonary barotrauma, blowout of the bronchial stump and pulmonary infection Pts with marginal reserve: Double lumen tube is exchanged with regular tube,extubated when criteria met

58. What are the available techniques for pain relief in this patient?

59. Thoracic epidural analgesia: gold standard for post-thoracotomy analgesia The epidural is most effective when placed at the vertebral level corresponding with the dermatomes of the surgical incision. Local anaesthetic solutions may be infused continuously or via a patient controlled device Opiods can be added Parenteral opioids: Patient-controlled analgesia (PCA) devices can be used to deliver opioids

60. Paravertebral blocks Intrathecal opioids Intercostal nerve blocks

61. Post-op complications of pneumonectomy ?

62. 1. Cardiovascular: a. Arrhythmias b. Right ventricular failure c. Cardiac herniation d. Hemorrhage 2. Pulmonary a. Pulmonary edema b. Respiratory insufficiency c. Pulmonary torsion 3. Pneumonectomy space a. Bronchopleural fistula b. Empyema 4. Neurological Recurrent laryngeal, vagus or phrenic nerve injury

63. Indication of thoracotomy once ICTD is placed?

64. > 1.5 L once ICTD is placed. > 200ml/hr for consecutive 4 hrs Clotted hemothorax Persistent pneumothorax

65. What are the indications of chest tube insertion

66. Asymptomatic patients with minimal pneumothorax (< 15–20% of hemithorax ) : conservative management Symptomatic or patients with larger pneumothorax need aspiration or drainage ICTD indications : 1. Pneumothorax In mechanically ventilated patient Tension pneumothorax after initial decompression by inserting a needle Persistent or recurrent pneumothorax after simple aspiration

67. 2 . Large or symptomatic pleural effusions 3. Other pleural collections Pus (empyema) Blood ( hemothorax ) Chyle ( chylothorax ) 4. Postoperative—after thoracotomy or thoracoscopy