Anesthesia for Pneumonectomy

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Anesthesia for Pneumonectomy : 

Anesthesia for Pneumonectomy Dr Gagan Pal Singh

Slide 2: 

Preoperative assessment Intraoperative management Monitoring Lung isolation techniques Positioning One lung Ventilation Postoperative management Postoperative analgesia Complications

Preoperative Assessment : 

Preoperative Assessment Aim Identify patients at high risk Use that risk assessment to stratify perioperative management and focus resources on the high-risk patients to improve their outcome.

Assessment of Respiratory function : 

Assessment of Respiratory function Detailed history Baseline Spirometry Respiratory Mechanics Lung parenchymal function Cardiopulmonary interaction

Respiratory mechanics : 

Respiratory mechanics For example, after a right lower lobectomy a patient with a preoperative FEV1 (or DLCO) 70% of normal would be expected to have a postoperative FEV1 = 70% × (1 - 29/100) = 50% ppoFEV1% = preop FEV1% × (1- %Functional lung tissue removed/100) Slinger PD, Johnston MR: Preoperative assessment: an anesthesiologist's perspective. Thorac Surg Clin 15:11, 2005. Ppo FEV1 >40% -Low risk 30-40%- mod risk < 30% - high risk

Lung Parenchymal Function : 

Lung Parenchymal Function Diffusing capacity for CO (DLCO) Useful predictor of perioperative mortality but not long term survival. ppoDLco <40% predicted correlates with both increased respiratory and cardiac complications and is independent of the FEV1.

Cardiopulmonary Interaction : 

Cardiopulmonary Interaction Maximum oxygen consumption (Vo2max) Most useful predictor of post-thoracotomy outcome. Morbidity and mortality is unacceptably high- Vo2max <15 mL/kg/min. Few patients with a Vo2max >20 mL/kg/min have respiratory complications Stair climbing 5 flights - Vo2max >20 mL/kg/min 2 flights - Vo2max of 12 mL/kg/min 6-minute test (6MWT) <2000 ft (610 m) - Vo2max <15 mL/kg/min Patients with a decrease of Spo2 greater than 4% during exercise are at increased risk for morbidity and mortality.

Ventilation-Perfusion Scintigraphy : 

Ventilation-Perfusion Scintigraphy Pneumonectomy patient who has a preoperative FEV1 and/or DLCO less than 40%. Split Function Tests Unilateral exclusion of a lung or lobe with an endobronchial tube/blocker or by pulmonary artery balloon occlusion of a lung or lobe artery, or by both.

Comorbid Conditions : 

Comorbid Conditions Cardiovascular Diseases Ischemia “intermediate risk” procedure in terms of perioperative cardiac ischemia. Documented incidence is 5% and peaks on 2 to 3 POD. History, physical examination, and electrocardiogram. Noninvasive testing is indicated in patients with Active cardiac conditions (unstable coronary syndromes, Decompensated CHF, severe valvular disease, significant arrhythmia) Therapeutic options for patients with significant cad optimization of medical therapy coronary angioplasty coronary artery bypass, either before or at the time of lung resection.

Timing of lung resection surgery : 

Timing of lung resection surgery ACC/AHA 2007 Guidelines on Perioperative Cardiovascular Evaluation and Care for Noncardiac Surgery .

Age >70 Yrs : 

Age >70 Yrs Respiratory complications – 40% (double than expected) Cardiac complications – 40% particularly arrhythmias (3 times than expected).

Age : 

Age

Renal Dysfunction : 

Renal Dysfunction Mortality – 18-20% Factors H/o of previous renal impairment Diuretic therapy Pneumonectomy Postoperative infection Blood transfusion

Chronic Obstructive Airway Disease : 

Chronic Obstructive Airway Disease Emphysema Peripheral Airway Disease Chronic Bronchitis Impairement of Expiratory Airflow Severity- FEV% stage I - >50% predicted stage II - 35% 50% stage III - <35%

Respiratory Drive : 

Respiratory Drive Earlier concept COPD pts relied on a hypoxic stimulus for ventilatory drive and became insensitive to Paco2. Hypercapnic coma by the administration of a high Fio2. Now Minute ventilation is basically unchanged. Relative decrease in alveolar ventilation and an increase in alveolar dead space Redistribution of perfusion away from lung areas of relatively normal V/Q matching to areas of very lowV/Q ratio. A minor fraction of the increase in Paco2 is due to a diminished respiratory drive. Supplemental oxygen must be administered postoperatively to prevent the hypoxemia associated with the unavoidable fall in FRC. The attendant rise in Paco2 should be anticipated and monitored.

Nocturnal Hypoxemia : 

Nocturnal Hypoxemia Rapid/shallow breathing pattern during REM sleep. This tendency to desaturate, combined with the postoperative fall in FRC and opioid analgesia, places these patients at high risk for severe hypoxemia postoperatively during sleep.

Right ventricular dysfunction : 

Right ventricular dysfunction 50% of COPD patients. poorly tolerant of sudden increases in afterload, such as the change from spontaneous to controlled ventilation. Cor pulmonale - 40% in pts with an FEV1 <1 L 70% with an FEV1 <0.6 L. Pneumonectomy candidates with a ppoFEV1 less than 40% should have transthoracic echocardiography to assess right-sided heart function. Elevation of right-sided heart pressures places these patients in a very high-risk group. The only therapy that has been shown to improve long-term survival and decrease right-sided heart strain in COPD is oxygen. COPD patients with resting PaO2 <55 mm Hg & <44 mm Hg with usual exercise should receive supplemental home oxygen. The goal of supplemental oxygen is to maintain a PaO2 of 60 to 65 mm Hg.

Bullae : 

Bullae Chances of Bullae rupture, tension pneumothorax and bronchopleural fistula with positive-pressure ventilation Keep low airway pressures Equipment should be available to insert a chest drain and obtain lung isolation if necessary.

Flow Limitation : 

Flow Limitation Risk for hemodynamic collapse with the application of positive-pressure ventilation owing to dynamic hyperinflation of the lungs.

Difficult Endobronchial Intubation : 

Difficult Endobronchial Intubation History Previous radiotherapy Infection Prior pulmonary or airway surgery Written bronchoscopy report with detailed description of anatomic features. Physical findings The most useful predictor is plain chest radiograph

Prediction of Desaturation during OLV : 

Prediction of Desaturation during OLV High percentage of ventilation or perfusion to the operative lung on preoperative ventilation- perfusion scan    Poor PaO2 during two-lung ventilation, particularly in the lateral position intraoperatively    Right-sided thoracotomy    Restrictive lung disease    Supine position during one-lung ventilation

Preoperative Optimization : 

Preoperative Optimization Stop smoking, avoid industrial pollutants Dilate airways Loosen secretions Airway hydration (humidifier/nebulizer) Systemic hydration Mucolytic and expectorant drugs Remove secretions Postural drainage Coughing Chest physiotherapy (percussion and vibration) Adjunct medication Antibiotics—if purulent sputum/bronchitis Antacids, H2 blockers, or PPIs—if symptomatic reflux. Increased education, motivation, and facilitation of postoperative care Psychological preparation Preoperative pulmonary care training Incentive spirometry Secretion removal maneuvers Preoperative exercise Weight loss/gain Stabilize other medical problems

Summary of initial preoperative assessment : 

Summary of initial preoperative assessment All patients: Assess exercise tolerance estimate predicted postoperative FEV1% discuss postoperative analgesia discontinue smoking Patients with predicted postoperative FEV1< 40%: Dlco Ventilation perfusion Scan Vo2 max Cancer patients: consider the “4 Ms”: mass effects metabolic effects Metastases medications    COPD patients: Arterial blood gas analysis Physiotherapy bronchodilators    Increased renal risk: Measure creatinine and blood urea nitrogen

Final Assessment : 

Final Assessment Review initial assessment and test results.    Assess difficulty of lung isolation: examine chest radiograph and computed tomography scan.    Assess risk of hypoxemia during one-lung ventilation.

Intraoperative Monitoring : 

Intraoperative Monitoring Oxygenation Capnometry Arterial blood pressure CVP Pulmonary artery pressure Fibreoptic bronchoscopy Urine output Temperature

Transesophageal Echocardiography : 

Transesophageal Echocardiography

Lung Isolation Techniques : 

Lung Isolation Techniques Double lumen tube Bronchial blocker Arndt Cohen Fuji Univent tube Endobronchial tube Endotracheal tube advanced into bronchus

Double lumen tube : 

Double lumen tube Carlens tube Robertshaw tube Advantages Quickest to place successfully Repositioning rarely required Bronchoscopy to isolated lung Suction to isolated lung CPAP easily added Can alternate OLV to either lung easily Placement still possible if bronchoscopy not available Disadvantages Size selection more difficult Difficult to place in patients with difficult airways or abnormal tracheas Not optimal for postoperative ventilation Potential laryngeal trauma Potential bronchial trauma

Size selection : 

Size selection Depth of insertion 12 + (patient height/10) cm

Method of insertion : 

Method of insertion Blind technique: DLT is passed with direct laryngoscopy Turn 90 ° counterclockwise (for a left-sided DLT placement) after the endobronchial cuff has passed beyond the vocal cords. The DLT should pass the glottis without any resistance. Bronchoscopic guidance Tip of the endobronchial lumen is guided into the correct bronchus after the DLT passes the vocal cords using direct vision with a flexible fiberoptic bronchoscope

Confirmation of tube placement : 

Confirmation of tube placement Auscultation “three-step” method:  Step 1. During bilateral ventilation, the tracheal cuff is inflated to the minimal volume that seals the air leak at the glottis. confirm bilateral ventilation.  Step 2. The tracheal lumen is clamped proximally and the port distal to the clamp opened. During ventilation via the bronchial lumen the bronchial cuff is inflated to the minimal volume that seals the air leak from the open tracheal lumen port. Auscultate to confirm correct unilateral ventilation.  Step 3. The tracheal lumen clamp is released and the port closed. Auscultate to confirm resumption of bilateral breath sounds.

Fiberoptic bronchoscopy : 

Fiberoptic bronchoscopy Tracheal View Confirm endobronchial portion in the left bronchus Bronchial cuff herniation over the carina after inflation. identify the takeoff of the right upper lobe bronchus through the tracheal view. Going inside this right upper lobe with the bronchoscope should reveal three orifices (apical, anterior, and posterior). Endobronchial view check for patency of the tube Determination of margin of safety The orifices of both the left upper and lower lobes must be identified to avoid distal impaction in the left lower lobe and occlusion of the left-upper lobe

Slide 37: 

view from the distal bronchial lumen Tracheal view

Right-Sided Double-Lumen Endobronchial Tubes : 

Right-Sided Double-Lumen Endobronchial Tubes Distorted Anatomy of the Entrance of Left Mainstem Bronchus External or intraluminal tumor compression Descending thoracic aortic aneurysm Site of Surgery Involving the Left Mainstem Bronchus Left lung transplantation Left-sided tracheobronchial disruption Left-sided pneumonectomy Left-sided sleeve resection

Bronchial blockers : 

Bronchial blockers Pts with previous oral or neck surgery who present with a challenging airway Pts with previous contralateral pulmonary resection when postoperative mechanical ventilation is being considered after prolonged thoracic or esophageal surgery.

Cohen Blocker : 

Cohen Blocker Wheel in the proximal part of the unit deflects the tip of the distal part of the blocker into the desired bronchus. Distal tip is preangled to facilitate insertion into a target bronchus. Arrow on the distal shaft above the balloon To position the Cohen blocker, the arrow is aligned with the bronchus to be intubated, the proximal wheel is turned to deflect the tip toward the desired side and then the blocker is advanced with fiberoptic guidance.

Arndt Blocker : 

Arndt Blocker

Disadvantages of Bronchial Blockers : 

Disadvantages of Bronchial Blockers More time consuming Repositioning needed more often Bronchoscope essential for positioning Nonoptimal right lung isolation due to RUL anatomy Bronchoscopy to isolated lung impossible Minimal suction to isolated lung Difficult to alternate OLV to either lung

Univent Bronchial blockers : 

Univent Bronchial blockers Enclosed bronchial blocker is fully retracted into the standard lumen of the tube. Conventional endotracheal tube intubation technique is used. Then a fiberoptic bronchoscope is passed into the main lumen through a bronchoscopy adaptor. Under direct vision the enclosed bronchial blocker is advanced into the targeted bronchus

Positioning : 

Positioning Position Change W/f hypotension Secure all lines and monitors Make an initial “head-to-toe” survey Check oxygenation, ventilation, hemodynamics, lines, monitors, and potential nerve injuries. Reassess after repositioning Recheck Endobronchial tube/blocker position and the adequacy of ventilation by auscultation and fiberoptic bronchoscopy after repositioning.

Neurovascular Complications : 

Neurovascular Complications Brachial Plexus Injury Dependent Arm (Compression Injuries) Arm directly under thorax   Pressure on clavicle into retroclavicular space   Cervical rib   Caudal migration of thorax padding into the axilla Nondependent Arm (Stretch Injuries)    Lateral flexion of cervical spine Excessive abduction of arm (>90%)   Semiprone or semisupine repositioning after arm fixed to a support

“Head-to-Toe” Survey : 

“Head-to-Toe” Survey Dependent eye   Dependent ear pinna   Cervical spine in line with thoracic spine Dependent arm:    Brachial plexus Circulation   Nondependent arm:    Brachial plexus Circulation   Dependent and nondependent suprascapular nerves   Nondependent leg: sciatic nerve   Dependent leg: Peroneal nerve   Circulation

Lateral decubitus position for thoracotomy : 

Lateral decubitus position for thoracotomy

Awake Vs Anaesthetized In Lateral position : 

Awake Vs Anaesthetized In Lateral position Non dependent lung moving from a flat, noncompliant portion to a steep, compliant portion Dependent lung moving from a steep, compliant part to a flat, noncompliant part. Thus, an anesthetized patient in a lateral decubitus position has more of the tidal ventilation in the nondependent lung (where perfusion is the least) and less of the tidal ventilation in the dependent lung

Open paralyzed Chest in lateral position : 

Open paralyzed Chest in lateral position Opening the chest increases nondependent lung compliance Paralysis also reinforces or maintains the larger part of tidal ventilation going to the nondependent lung because the pressure of the abdominal contents (PAB ) pressing against the upper part of the diaphragm is minimal

compliance of a single lung during position changes in an anesthetized, paralyzed patient during controlled mechanical ventilation : 

compliance of a single lung during position changes in an anesthetized, paralyzed patient during controlled mechanical ventilation

One Lung Ventilation : 

One Lung Ventilation

Determinants of pulmonary blood flow : 

Determinants of pulmonary blood flow

Hypoxic Pulmonary Vasoconstriction : 

Hypoxic Pulmonary Vasoconstriction Decrease the blood flow to the nonventilated lung by 50%. Primary stimulus is Pao2 ↓ Pao2 stimulates precapillary vasoconstriction redistributing pulmonary blood flow via a pathway involving NO and/or cyclooxygenase synthesis inhibition Rapid onset over the first 30 minutes and then a slower increase to a maximal response at approximately 2 hours. Preconditioning effect response to a second hypoxic challenge will be greater than to the first challenge

One-Lung Ventilation… : 

One-Lung Ventilation… Thoroughly de-nitrogenate the operative lung, before collapse Recruitment maneuver (holding the lung at an end-inspiratory pressure of 20 cm H2O for 15 to 20 sec) immediately after the start of OLV to decrease atelectasis

Hypoxemia during OLV : 

Hypoxemia during OLV Incidence 1950-1980 -20% to 25% 1990s - <10% Factors: Improved lung-isolation techniques such as routine fiberoscopy to prevent lobar obstruction from DLTs Improved anesthetic techniques that cause less inhibition of HPV Better understanding of the pathophysiology of OLV

Treatment of Hypoxemia : 

Treatment of Hypoxemia Severe or precipitous desaturation: Resume two-lung ventilation (if possible). Gradual desaturation:   Ensure that delivered FIO2 is 1.0 Check position of DLT or blocker with fiberoptic bronchoscopy Ensure cardiac output is optimal; decrease volatile anesthetics to < 1 MAC Apply a recruitment maneuver to the ventilated lung Apply PEEP 5 cm H2O to the ventilated lung Apply CPAP 1-2 cm H2O to the nonventilated lung (apply a recruitment maneuver to this lung immediately before CPAP) Intermittent reinflation of the nonventilated lung   Partial ventilation techniques of the nonventilated lung: Oxygen insufflation High-frequency ventilation   Lobar collapse (using a bronchial blocker) Mechanical restriction of the blood flow to the nonventilated lung

Anesthetic Management : 

Anesthetic Management Fluid Management First 24-hour perioperative total positive fluid balance should not exceed 20 mL/kg.    crystalloid administration should be limited to < 3 L in the first 24 hours. No fluid administration for third space fluid losses during pulmonary resection.    Urine output > 0.5 mL/kg/hr is unnecessary. If increased tissue perfusion is needed postoperatively, it is preferable to use invasive monitoring and inotropes rather than to cause fluid overload. Avoid N2O - more prone to cause atelectasis in poorly ventilated lung regions Maintenance of body temperature Prevention of Bronchospasm

Ventilation Strategies : 

Ventilation Strategies

Postoperative mangement- Analgesia : 

Postoperative mangement- Analgesia Systemic Analgesia Opioids Nonsteroidal Anti-inflammatory Drugs Ketamine Dexmedetomidine Local Anesthetics/Nerve Blocks Intercostal Nerve Blocks Intrapleural Analgesia Epidural Analgesia Paravertebral Block

Thoracic Epidural Analgesia : 

Thoracic Epidural Analgesia Better preservation of the functional residual volume Efficient mucociliary clearance Alleviation of the inhibiting reflexes acting on the diaphragm prevention of atelectasis and secondary infections

Postoperative Complications : 

Postoperative Complications Early Major Complications Torsion of a remaining lobe after lobectomy Dehiscence of a bronchial stump Hemorrhage from a major vessel Respiratory Failure Cardiac Herniation

Respiratory Failure : 

Respiratory Failure Acute onset of hypoxemia (PaO2 < 60 mm Hg) hypercapnia (PaCO2 > 45 mm Hg) use of postoperative mechanical ventilation for >24 hours Reintubation for controlled ventilation after extubation Incidence - 2% - 18%

Respiratory Failure… : 

Respiratory Failure… Predictors Preoperatively decreased respiratory function Age Presence of coronary artery disease Extent of lung resection Crossover contamination Prolonged mechanical ventilation postoperatively

Respiratory Failure… : 

Respiratory Failure… Chest physiotherapy, incentive spirometry, and early ambulation are crucial Early extubation is desirable for an uncomplicated lung resection. Current therapy to treat acute respiratory failure is supportive therapy to provide better oxygenation, treat infection, and provide vital organ support without further damaging the lungs.

Cardiac Herniation : 

Cardiac Herniation If the pericardium is incompletely closed or the closure breaks down immediately or within 24 hours after chest surgery Mortality -50%. Clinical presentation after a right pneumonectomy Impairment of the venous return to the heart Increase in central venous pressure Tachycardia Profound hypotension Shock. Acute SVC syndrome due to the torsion of the heart. Clinical presentation after a left pneumonectomy There is less cardiac rotation but the edge of the pericardium compresses the myocardium myocardial ischemia Arrhythmias ventricular outflow tract obstruction.

Cardiac Herniation - management : 

Cardiac Herniation - management consider as dire emergent surgery. The differential diagnosis massive intrathoracic hemorrhage pulmonary embolism mediastinal shift from improper chest drain management. Early diagnosis and immediate surgical treatment by relocation of the heart to its anatomic position with repair of the pericardial defect or by the use of analogous or prosthetic patch material is key to patient survival.

Arrhythmias : 

Arrhythmias Incidence - 30% to 50% 60% to 70% are atrial fibrillation Factors: Extent of lung resection Pneumonectomy – 60% Lobectomy – 40% Nonresection thoracotomy - 30%) Intrapericardial dissection Intraoperative blood loss Age of the patient. Extrapleural pneumonectomy

Slide 69: 

Antiarrhythmic Prophylaxis Diltiazem Thoracic epidural analgesia Due to increasing myocardial refractory period, decreasing ventricular diastolic pressures, and improving endocardial/epicardial blood flow ratios. Oka T, Ozawa Y, Ohkubo Y: Thoracic epidural bupivacaine attenuates supraventricular tachyarrhythmias after pulmonary resection.  Anesth Analg  2001; 93:253.

Slide 70: 

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