3. 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.
4. Assessment of Respiratory
function
Detailed history
Baseline Spirometry
Respiratory Mechanics
Lung parenchymal function
Cardiopulmonary interaction
5. Respiratory mechanics
ppoFEV1% = preop FEV1% ×
(1- %Functional lung tissue removed/100)
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%
Ppo FEV1
>40% -Low risk
30-40%- mod risk
< 30% - high risk
Slinger PD, Johnston MR: Preoperative assessment: an anesthesiologist's perspective. Thorac Surg Clin 15:11, 2005.
6. 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.
7.
8.
9. Preoperative Optimization
• Stop smoking, avoid industrial • Adjunct medication
pollutants – Antibiotics—if purulent
• Dilate airways sputum/bronchitis
• Loosen secretions – Antacids, H2 blockers, or
PPIs—if symptomatic reflux.
– Airway hydration
(humidifier/nebulizer) • Increased education,
– Systemic hydration motivation, and facilitation of
– Mucolytic and expectorant
postoperative care
drugs – Psychological preparation
• Remove secretions – Preoperative pulmonary care
training
– Postural drainage • Incentive spirometry
– Coughing • Secretion removal maneuvers
– Chest physiotherapy – Preoperative exercise
(percussion and vibration) – Weight loss/gain
– Stabilize other medical
problems
10.
11. Summary of initial preoperative
assessment
All patients: Cancer patients:
Assess exercise tolerance consider the “4 Ms”:
mass effects
estimate predicted
metabolic effects
postoperative FEV1%
Metastases
discuss postoperative medications
analgesia COPD patients:
discontinue smoking Arterial blood gas analysis
Patients with predicted Physiotherapy
postoperative FEV1< 40%: bronchodilators
DlCO Increased renal risk:
Ventilation perfusion Scan Measure creatinine and
VO2 max blood urea nitrogen
14. Double lumen tube
Carlens tube
Robertshaw tube
Advantages
Quickest to place successfully Disadvantages
Repositioning rarely required Size selection more difficult
Bronchoscopy to isolated lung Difficult to place in patients
Suction to isolated lung with difficult airways or
abnormal tracheas
CPAP easily added
Not optimal for postoperative
Can alternate OLV to either ventilation
lung easily
Potential laryngeal trauma
Placement still possible if
bronchoscopy not available Potential bronchial trauma
16. 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.
18. 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
19. Ventilation Strategies
Parameter Suggested Guidelines/ Exceptions
Maintain:
Tidal volume 5-6 mL/kg
Peak airway pressure <
35 cm H2O
Plateau airway pressure <
25 cm H2O
Positive end-expiratory Patients with COPD: no
5 cm H2O
pressure added PEEP
Maintain normal PaCO2;
Pa-ETCO2 will usually
Respiratory rate 12 breaths/min
increase 1-3 mm Hg during
OLV
Pressure control for
patients at risk of lung
Volume or pressure
Mode injury (e.g., bullae,
controlled
pneumonectomy, post lung
transplantation)
21. 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
22. 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
23. Anaesthetic management of bronchopleural fistula
Bronchopleural fistula
Communication from major bronchus to pleural space
Commonly associated with pneumonectomy, trauma,
abscess or empyema
Relevant complications
Pus may contaminate other lung-associated injuries with trauma
Surgery
Usually semi-elective
Resuturing of bronchial stump, muscle flap to stump,
drainage of abscess
High risk surgery requiring GA and one-lung ventilation
If incidental surgery, GA may be avoided, regional preferred
Positioning still important to avoid soiling
24. Patient
Commonly debilitated, may have coexistent medical
problems
Respiratory function assessed
Clinical, spirometry, ABGs
Routine assessment for thoracic surgery
Consideration of epidural
Decision to proceed
Respiratory function optimized
Chest drain inserted to avoid tension pneumothorax and
drain pleural collection
25. Induction
Objectives
Maintain oxygenation and ventilation, avoid tension pneumothorax
Avoid soiling good lung
Protection of lung requires DLT, bronchial lumen to good side
Small leak without infection may be manageable with single-lumen
ETT
Paediatric patients are typically too small for DLT or FOB -->
blocker or endobronchial intubation
Fistula reduces effectiveness of mask IPPV, so spontaneous
ventilation
Ideally awake DLT intubation
Topical local anaesthetic to airway
Position head-up and bad side down
Sedation for intubation
Alternatively spontaneously ventilating GA with DLT insertion
when deep
Verification of DLT position with differential ventilation or FOB
26. Maintenance
IPPV to healthy lung
Lung with fistula may benefit from small VT ventilation
or CPAP below critical pressure for fistula or HFJV
Emergence
Avoid high airway pressures if fistula has been repaired
Hand ventilation or SIMV
Postoperative
Epidural analgesia
HDU monitoring post-op
High incidence of arrhythmia post-thoracotomy
