Use of One-Lung Ventilation for Thorasic Surgery

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Use of One-Lung Ventilation for Thorasic Surgery

• Sun Young Kim

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Objectives

• Definition and Indications
• Physiology associated with OLV
• Techniques
• Complications and management

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Introduction

• One Lung Ventilation (OLV)
• Collapse of the lung in the operative hemithorax
  and ventilation of the lung in the contralateral
  hemithorax
• OLV provides
• Protection of healthy lung
• Diversion of ventilation from damaged airway
• Improved exposure of surgical field
• OLV cause physiological change

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Ventilation-Perfusion Relationships in the Lung
during Anesthesia
Ventilation / no perfusion
Ventilation / perfusion
Intermittent Ventilation
atelectasia
No Ventilation
Anatomic shunt
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Physiology of Lateral Recumbent Position

• Ventilation-to-Perfusion Mismatching
• Ventilation
• Most of the tidal volume distributed to the
  superior lung
• Lung volumes decrease in the inferior lung
• Abdominal organ
• Mediastinal structure
• positioning and roll pads
• Perfusion
• 40 of cardiac output ? the superior lung
• 60 of cardiac output ? the inferior lung

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Physiology of Lateral Recumbent Position

• V-Q relationships in anesthetized, open-chest in
  Lat. Recumbency

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Physiology of OLV
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Physiology of OLV

• Redistribution of Lung perfusion
• Active mechanism
• Hypoxic Pulmonary Vasoconstriction
• Passive mechanism
• Gravity, Surgical manipulation, pulmonary
  vascular ligation

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Physiology of OLV

• HPV
• A local response of pulmonary artery smooth
  muscle
• Aids in keeping a normal V/Q relationship by
  diversion of blood from areas with low
  ventilation
• Responsible for the most lung perfusion
  redistribution in OLV

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Physiology of OLV

• Redistribution of Lung perfusion
• Active mechanism
• Hypoxic Pulmonary Vasoconstriction
• Passive mechanism
• Gravity, Surgical manipulation, pulmonary
  vascular ligation

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Physiology of OLV

• Still hypoxic compartment can develop in the
  inferior lung
• Anesthesia
• Lateral posture
• Mechanical compression
• Secretion and fluid transudation
• Absorption atelectasis ? focal HPV

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OLV Techniques

• Bronchial blockade
• Endobronchial intubation
• Double-lumen endotracheal Tube (DLT)

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Bronchial Blockade
Capped proximal end of hollow BB
Proximal main lumen

• Isolated bronchial blocker
• Univent Tube
• Movable blocker shaft in external Lumen of
  single-lunmen ET tube
• Easier to insert and properly position
• Aspiration / CPAP
• Blocker can become dislodged
• Slow to deflate the lung

Pilot tube to BB cuff
Pilot tube to main cuff
Main cuff
BB cuff
Distal end of hollow BB
Distal main lumen
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Endobronchial Intubation

• Single-lumen ET
• Smaller diameter than the bronchus
• Bronchoscope guide
• Careful placement
• End-hole / Murphy eye
• No aspiration
• No intermittent ventilation

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DLT

• Advantage
• Control ventilation of either lung
• Easy to apply suction / CPAP
• Easy to Deflate lung
• Disadvantage
• Difficult to insert (size and curve)
• Should be removed for post-op ventilation

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Possible Complicated situation

• Overinflation of the sealing balloon / cuff
• Passing tube too far
• Delayed lung collapse
• Adhesion
• Parenchymal Dz of lung
• Obstruction of gas flow
• Hypoxia

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Management of Hypoxia

• Administration of 100 O2
• Prevent HPV in the inferior lung
• Normal tidal volume
• Normal inspiratory pressure
• High inspiratory pressure increase vascular
  resistance ? increased blood flow to the superior
  lung
• Increased respiratory rate by about 20
• Avoid hypocapnia

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Management of Hypoxia

• Ventilation Technique
• PEEP
• Applied to the inferior lung
• Minimize atelectasis of the inferior lung
• Do not exceed 5 cm H2O
• CPAP
• Applied to the superior lung
• Administrate 100 O2 at 5-10 cm H2O
• PEEP CPAP

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Broncho-cath CPAP system
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Example

• OLV of an animal weighing approximately 20kg

Two lung ventilation
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Summary

• OLV can be used in cardiothorasic surgery and
  throcoscope
• Pinciple physiologic change of OLV
• Redistribution of pulmonary blood flow to keep an
  appropriate V/Q match
• Each of OLV methods have both advantage and
  disadvantage
• Optimal methods depends on indication, patient,
  equipment, skill and training
• Management of OLV is challenging and demands
  knowledge, skill, and practice