Hypoxia During Thoracic Surgery: Practical Advice for Anesthesia Providers Javier H. Campos, M.D. Professor Vice Chair for Clinical Affairs Director of Cardiothoracic Anesthesia Executive Medical Director of Operating Rooms Department of Anesthesia
Disclosure • Advisory board member of the ET View Medical, Ltd. • Paid consultant ET View Medical, Ltd.
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81 yo, 55 kg with RUL Ca: FVC 77%, FEV1 65%, DLCO 60% Tricuspid regurgitation/ PA systolic 70 mmHg During OLV SpO2 88%, PaO2 70 mmHg Tx: – alveolar recruitment maneuvers, – Pressure controlled ventilation, CPAP 5 cmH2O, PEEP 5 cmH2O • Outcome SpO2 99-100%, PaO2 132 mmHg – 2 hrs later PaO2 300 mmHg
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General Facts • Hypoxemia is a ↓ in SpO2 30 kg/m2 • >intraoperative hypoxemia • ↑ alveolar arterial O2 ∆
600 500
PaO2 mmHg
400
T
300
T
200 T
100
0 Pneumonectomy
Lobectomy
Metastasectomy VATS
After 30 min OLV
Schwarzkopf K, et al: Anesth Analg 2001; 92: 842–847
500 450
400 Supine COPD
Pao2 (mm Hg)
350 300
250
Lat. Normal PFTs
200 150
Sem. Lat. N PFTs
100 50
Supine Normal PFTs
0
0
10 20 Time of OLV (min)
30
Watanabe S, et al: Anesth Analg 2000; 90: 28-34 Bardoczky GI, et al: Anesth Analg 2000; 90:35-41
Factors that will Increase the Risk of Desaturation During OLV • High percentage of ventilation or perfusion to the operative lung on preoperative V/Q scan • Poor PaO2 during 2LV in lateral decubitus position
• Right-sided thoracotomy • Normal preoperative spirometry (FEV1 or FVC) • Supine position during OLV • Morbidly obese patient during OLV Slinger P, Campos JH: Anesthesia for Thoracic Surgery. Chapter 59 in: Miller’s Anesthesia, 7th edition, 2009, pp 1219-1287
PBF 40% • Hypoxia – reperfusion
• (HPV) 50% • Qs/Qt 15-40% • Systemic release of pro-inflammatory mediators
PBF 60% • Ventilator-induced lung injury • Pulmonary capillary stress failure • Reactive oxygen species production
Atelectasis During Anesthesia
• Pressure of abdominal organs • 40 cmH2O are required to open atelectatic lungs
Duggan M et al: Anesthesiology 2005; 102:838-54
Management of Intraoperative Hypoxemia • Observe surgical field • Increase FiO2 1.0%
• Restore 2LV • Check hemodynamics
• Check position of lung isolation device – Perform FOB Klein U, et al: Anesthesiology 1998; 88: 346-50
– Clear secretions and inspect bronchial segments Campos JH: Anesthesiology 2002; 97:1295-1301 Campos JH, et al: Curr Opin Anaesthesiol 2009; 22:4-10
• 38% malpositions among non-thoracic anesthesiologists (double-lumen tubes or bronchial blockers) • Lack of recognition of tracheobronchial anatomy • Lack of skills with FOB Campos JH, et al: Anesthesiology 2006; 104:261-6
Campos JH: Curr Opin Anaesthesiol 2009; 22: 4-10
Management of Intraoperative Hypoxemia Restoration of alveolar ventilation – Perform Recruitment maneuvers Unzueta MC, et al: Br J Anaesth 2012; 108: 517-24
– Applied CPAP 5 cmH2O to the non-dependent lung Capan LM, et al: Anesth Analg 1980; 59: 847-51
– Applied PEEP 5 cmH2O to the dependent lung Ren Y, et al: Anaesth Int Care 2008; 36: 544-48
– Applied PEEP 5-10 cmH2O during OLV in the morbid obese Zoremba M, et al: Anaesthesia 2010; 65: 124-129
– Selective lobar blockade during OLV (previous lobectomy) Campos JH: Anesth Analg 1997; 85: 583-86
Alveolar Recruitment Strategies Author
n
End Points
Outcome
Unzueta C, et al Br J Anaesth 2012; 108: 517-24
n=40
• Effects on oxygenation
• PaO2 control group 182 79
(prospective)
• ARS PIP 40cmH2O PEEP 20 cmH2O before and after OLV (1min)
• Peak end expiratory pressure for 10 breathes
• Effects of ARS on gas exchange during OLV
• PaO2 TLV 379 67 mmHg
n=20 control group 6ml•kg Vt n=20 ARS group
Tusman G, et al Anesth Analg 2004; 98: 1604-9
n=12 (prospective)
• ARS: PIP 40 cmH2O, Peak EEP 20 cmH2O, 10 breaths
• ARS group 251 69 During OLV 20 min
OLV 144 73mmHg ARS 244 89mmHg
• This may cause transient hypotension • Also a transient further decrease in PaO2 • Improvement on oxygenation and decrease alveolar dead space
COPD Normal PFT
Fujiwara M, et al: J Clin Anesth 2001; 13:473
Capan LM, et al: Anesth Analg 1980; 59:847
• CPAP must be applied to fully inflated recruited lung to be effective (5-10 Cm H20)
Campos JH: Anesth Analg 1997; 85:583-586 Campos JH, et al: Curr Opin Anaesthesiol 2009, 22:18-22
Lower Inflection Point
Slinger P, et al: Anesthesiology 2001; 95:1096-102
Volume (L)
Lower Inflection Point
Total PEEP
Slinger P, et al: Anesthesiology 2001; 95:1096-102
Auto-PEEP During OLV Author
n
End Points
Outcome
Yokota K, et al: Anesth Analg 1996; 82; 1007-1
• n=41 (Prospective)
• Magnitude of auto PEEP and measured PaO2 – OLV
• 2 LV auto-PEEP 18/41 (0.5-10cmH2O) • OLV auto PEEP 34/41 (0.5-10cmH2O) • Auto-PEEP during OLV correlated inversely with FEV1/FVC
Ducros l, et al: J Cardiothorac Vasc Anesth 1999; 13: 35-39
• n=28 (Prospective) 3 groups – No/moderate obs – Severe emphysema – Severe fibrosis
• Magnitude of pulmonary air trapping and auto PEEP
• Auto PEEP and ∆FRC occurred only during OLV • Auto PEEP related inversely to FEV1/FVC • No correlation PaO2 and auto PEEP
• Auto PEEP is difficult to measure • Worst FEV1/FVC >auto PEEP
The Effects of PEEP on Oxygenation during OLV Author
n
End Points
Outcome
Cohen E, et al J Cardiothorac Vasc Anesth 1996; 10: 578-82
n=18 (prospective)
• Hypothesis pts with low PaO2 (
