one lung anaesthesia

1. OLA – ONE LUNG ANESTHESIA PART 1
Dr Vinoth Natarajan MD DNB

2. SYNAPSIS
 Introduction
 How it is beneficial /How it is detrimental
 Indications
 Methods of OLA
 DLTs – what type needed?/wat size we choose?/insertion
techniques/successful placement/problems
 Bronchial blockers – types, insertion tecniques,problems
 Physiology of lateral decubitus and OLA
 Strategies to prevent hypoxemia during OLA
 OLA in special situation

3. INTRODUCTION
 Separation of two lungs and each lung functioning independently by
preparation of airway
 One among challenging and skilled techniques of anesthesia practice
 Selective lung ventilation – reported first in 1931
 Gale and waters – selective lung intubation with normal ETT
 Carlens – Double lumen tube in 1949

4. HOW IT IS USEFUL
 Protection of healthy lung from infected or bleeding one
 Diversion of ventilation from damaged airway or lung
 Improved exposure/access of surgical field
HOW IT IS DETRIMENTAL
 More airway manipulation – so more damage
 Significant physiological change and possible development of hypoxia

5. INDICATIONS
Absolute
1. Prevent spillage of infection
and blood
2. Control the distribution of
ventilation (e.g.BPF)
3. Unilateral bronchopulmonary
lavage (e.g. PAP)
Relative
1. Improve surgical access[strong] –
pneumonectomy, Upper lobectomy,
Thoracic aortic aneurysm repair,
Minimally invasive cardiac surgery,
VATS
2. Improve surgical access[weak] –
Esophageal surgery, mediastinal mass
reduction and middle/lower lobectomy

6. METHODS OF ACHIEVING OLA
 Double lumen tubes (DLTs)
 Bronchial Blockers
 Normal ETT with Fogarty catheter placement in selected lung.
 Single lung intubation with normal ETT

8. DLTS - TYPES
 Left sided DLTs ;– most preferred due to its ease of insertion (right
handed persons) and safety of margin is high
 Right sided DLTs ;– Murphy’s eye – for ventilating Right upper lobe
bronchus

9. DLTS – WHICH SIZE IS NEEDED
Age DLT’s size
8-10 26
10-12 26-28
12-14 28-32

10. LMBD (mm) <10 10 11 12 >12
DLT size (Fr) 32 35 37 39 41
OD bronchial lumen 8.7 9.6 10.2 10.7 11.2
Calculated allowance 1.3 0.4 0.8 1.3 >0.5

11. HOW IT IS INSERTED
 Integrity of tracheal and bronchial cuffs
 Lubricate well the outside of DLT
 Hold the DLT with its distal end concave anteriorly
 Perform Direct laryngoscopy and visualise the glottis
 Advance the DLT till the endobronchial cuff has passed the glottis and
the rotate it clockwise or anticlockwise (depending on type of DLT)
 Depth of insertion
 Successful placement confirmation – Auscultation, USG or FOB
FIXATION LENGTH = 12+ (PATIENT’S HEIGHT/10)

12. PROBLEMS RELATED TO DLTS
 Malposition (mc)
 Airway trauma
 Tension pneumothorax
 Difficult Airway (CL grade > 2b)
 Non availability of appropriate size FOB
Recent development - Vivasight-DL (camera at tracheal end)

13. BRONCHIAL BLOCKERS
 Blockade of a bronchus to allow lung collapse distal to the occlusion using
devices- collectively called as Bronchial Blockers
1. Fogarty’s vascular embolectomy catheter
2. Arndt 5 Fr, 7 Fr and 9 Fr (wire – guided)
3. Cohen 9 Fr (Wheel – based deflecting tip)
4. Fuji 5 Fr and 9 Fr (Pre-shaped distal tip)
5. Coopdech blocker 9 Fr and 7 Fr(Pre-shaped with suction port)
6. Rusch EZ blocker (Y shaped end: CPAP to other)
 All require FOB for insertion and placement into the respective bronchus

14. ARNDT ENDOBRONCHIAL BLOCKER

15. COHEN FLEXITIP ENDOBRONCHIAL BLOCKER

16. COOPDECH BLOCKER

17. RUSCH EZ BLOCKER

18. Bronchial blocker size Smallest recommended ETT for coaxial use FOB size
9 Fr (3 mm OD) 8.0mm < 4.0 mm
7 Fr (2.4 mm OD) 7.0mm < 3.5 mm
5 Fr (1.6 mm OD) 4.5mm < 2.0 mm
 So problem here is Non availability of appropriate size (mostly small
mm) FOBs

19. THEN WHAT CAN BE DONE
 Normal adult size ETT
 Adult size fibreoptic bronchoscope
 Ureteral guidewire (used in URS patients)
 Placing the ureteral guidewire with the help of FOBs in the required
bronchus and remove FOBs.
 Guide the coopdech endobronchial blocker through it and selective
lung isolation can be achieved.

21. FOGARTY’S VASCULAR EMBOLECTOMY CATHETER
 Suitable for lung isolation in pediatric patients

22. TIPS OF VARIOUS BBS

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25. AIRWAY EXCHANGE CATHETER
 Essential airway guide in thoracic anesthesia
 AEC of atleast 70 cm length when using with
DLTs
 Always lubricate the AEC
 Test the fit between AEC and tube before
attempting tube exchange
 Frova intubating introducer – designed specially
for DLTs
 Have a set for jet ventilation available

26. PHYSIOLOGY OF LATERAL DECUBITUS AND OLV
 Distribution of ventilation
 Open chest
 Pulmonary blood flow
1) Hypoxic pulmonary vasoconstriction
2) Gravity
3) Non gravitational factors

27. VENTILATION – UPRIGHT VS LATERAL

28. VENTILATION IN LATERAL DECUBITUS – AWAKE VS ANESTHESIZED

29.  Reasons-
1) Induction of anesthesia with neuromuscular paralysis
2) Compression of dependent lung (reduce FRC) and restriction of its
excursion (decrease in compliance) by the mediastinum
3) Cephalic movement of abdominal organs via flaccid diaphragm
4) Exaggerated flexed position with chest rolls to free the axillary
contents
5) Positive Pressure Ventilation favours ND lung as it is more compliant
VENTILATION IN LATERAL DECUBITUS – AWAKE VS ANESTHESIZED

30. VENTILATION IN LATERAL DECUBITUS/ANESTHESIZED –
CLOSED VS OPEN CHEST
 Further aggravation of difference
in the compliance between
dependent and non dedpendent
lung as ND has no restriction.

31. PULMONARY BLOOD FLOW (PERFUSION) – WEST’S ZONES OF LUNG
 Principle determinant – gravity
 Least flow in zone 1 and best in
zone 3
 Zone 4 – blood flow less than zone
3 (because of increased interstitial
pressure and increased resistance
provided by extra-alveolar blood
vessels

32. PERFUSION - UPRIGHT VS LATERAL

33. HYPOXIC PULMONARY VASOCONSTRICTION
 HPV, a local response of pulmonary vascular smooth muscle (PVSM),
decreases blood flow to the area of lung where a low alveolar oxygen
pressure is sensed.
 Intrinsic response of lung, no neuronal control, immediately present in
transplanted lung.
 The mechanism is not completely understood. Vasoactive substances
released by hypoxia or hypoxia itself (K+ channel) cause pulmonary artery
smooth muscle contraction.
 All pulmonary arteries and veins response to hypoxia, but greatest effect
is small pulmonary arteriole

34.  HPV aids in keeping a normal V/Q relationship by diversion of blood from
underventilated areas, responsible for the most lung perfusion redistribution
in OLV.
 HPV is graded and limited, of greatest benefit when 30% to 70% of the lung
is made hypoxic
 But effective only when there are normoxic areas of the lung available to
receive the diverted blood flow
 During OLA, the percentage of lung that is atelectatic is usually between
30% to 70% and this falls within the range of effective HPV
HYPOXIC PULMONARY VASOCONSTRICTION

35. BLOOD FLOW DLV VS OLV

36. SHUNT CALCULATION AND OLV
 Physiological (postpulmonary) shunt
About 2-5% CO,
Each lung contribute 5% in obligatory shunt
Accounting for normal A-aD02, 10-15 mmHg
 Including drainages from
1) Thebesian veins of the heart
2) The pulmonary bronchial veins
3) Mediastinal and pleural veins
 Shunt equation

37.  Assuming active HPV, blood flow to the nondependent hypoxic lung will
be reduced by 50% and therefore is (35/2) = 17.5%.
 To this must be added 5%, which is the obligatory shunt through the
nondependent lung. shunt through the nondependent lung is therefore
22.5% Together with the 5% shunt in the dependent lung, total shunt
during one-lung ventilation is 22.5% + 5 = 27.5%.
 This results in a PaO2 of approximately 150 mm Hg (FIO2 = 1.0).

38. SUMMARY
 Now, the dependent lung in OLV
1) Decreased compliance (not on steep portion of volume pressure curve)
- reduced lung volume and FRC
2) has a large P(A-a) O2 gradient
- due to shunt effect

39. QUESTION
 If surgeon wants the collapse of only left lower lobe and remaining all
other portions of lungs can be ventilated , how will you achieve???
 Already right pneumonectomy patient is now presenting with spread of
infection to left upper lobe, how will you proceed???