One Lung Ventilation (OLV) is a technique that isolates ventilation to one lung during surgery using double lumen tubes (DLTs) or bronchial blockers. DLTs allow control of ventilation to each lung and switching between single and dual lung ventilation. Placement is confirmed with fiberoptic bronchoscopy. OLV reduces the risk of cross contamination during certain procedures. Preoperative pulmonary function tests assess risk, with an FEV1 <40% or DLCO <40% indicating high risk. During OLV, hypoxic pulmonary vasoconstriction and gravity divert blood flow away from the non-ventilated lung to reduce shunting. Anesthesia aims to maintain cardiovascular stability and minimize inhibition of hypo

1. One Lung Ventilation
Dr. Malaka Munasinghe
Registrar in Anaesthesia
2016.09.23

2. O A technique that allows isolation of the
individual lungs under anaesthesia

5. Techniques of OLV
O Double lumen tubes( DLTs)
- Allow control over ventilation of both lungs
and faster switching from single lung to
dual lung ventilation
- Allow suction
- Alllow application of CPAP/PEEP to each
lung when necessary

6. Types of DLTs

7. Carlen’s DLT

8. Robertshaw DLT

9. Robertshaw ETT

10. DLTs ctd…
O Plastic disposable tubes
O sizes 26 – 41 Fr( Internal diameter 4.5-
6.5mm per lumen)
O 37 – 39 Fr- adult females
O 39 –41 Fr – adult males
O 26 Fr- 8-10 yr old children weighing 25-35
Kg

11. Ensuring correct placement
O Visual inspection/auscultation/use of a
paediatric fiberooptic broncoscope( outer
diameter- 3.6mm-4.2mm)
O Prior to insertion- patency of both tracheal and
endobronchial balloons checked
O use of a stylet in bronchial lumen
O With passage of bronchial lumen just pass the
vocal cords- A 70-90 degree rotation of the
tube when performed in the direction of the
bronchus need to be intubated (clockwise
rotation for a right sided tube or counter
clockwise for a left sided tube)

12. O With resistance, Stop advancing further
O Tube connected to the anaesthetic circuit
O Tracheal cuff inflated until no air leak
O Bilateral chest movement and air entry is
confirmed by auscultation
O Note the peak airway pressures

15. Bronchial blockers
O Use has increased recently and a number of new
models have become available
O Consist of a balloon and a central lumen
O Application of suction and lung deflation or supply of
oxygen
O Individual bronchial blockers

16. O Bronchial blockers with tracheal tubes

17. Uses
O When lung resection is not required
O Reduced risk of cross-contamination (e.g. pleural
surgery, lung biopsy, and oesophagectomy)
O Increased postoperative hoarseness and vocal
cord lesions with DLT’s than with endobronchial
blockers
O Increased dislodgment and airway obstruction with
hypoxeamia with endobronchial tubes

18. Endobronchial intubation, with
standard ETT
- In emergencies or when specialized equipment not
available
- Increased risk of bronchial damage/ ineffficient Mx of
hypoxic episodes
O Tracheal intubation in combination with a
balloon tipped catheter
- Insertion of fogarty embolectomy or foley catheters into the
main bronchi, and inflating the balloons
- paediatric patients - pulmonary artery floatation (Swan-
Ganz) catheter

19. Assessment of suitability for OLV
O Reduced exercise tolerance
O Dyspnoea at rest
O Associated cardiovascular problems
O Co-pulmonale and Pulmonary
hypertension
( poor candidates for OLV)

20. Tests
O used to predict the perioperative risk of
respiratory failure
O Postoperative respiratory reserve
( pulmonary function)

21. 1. Spirometry
- FEV1- < 50% pedicted or <2L/min
( most sensitive indicator of periop respiratory
complications)
- FVC < 50% pedicted
- MBC < 50% pedicted
- RV/TLC < 50% pedicted

22. O Surgical suitability with FEV1
- >80% or >2L for Pneumonectomy – no
further testing required
- >80% or >1.5L Lobectomy – no further
testing required

23. O If FEV1
<80% or <2L for Pneumonectomy
<80% or <1.5L for Lobectomy
- Calculate ppo FEV1
- Perform transfer factor (DLCO), and
express as % of predicted DLCO
- Saturations (SaO2) on air

24. O predicted postoperative FEV1 (ppo FEV1)
- ppo FEV1 = FEV1 x (19-y)/19
- 19= Total number of lung segments
- Y = Number of segments to be resected

25. O ppo FEV1 <40% and DLCO <40% = HIGH
RISK ( further exercise tests required)
O ppo FEV1 >40% and DLCO >40% and
SaO2>90% = AVERAGE RISK

26. Shuttle walk test:
O <25 shuttles or desaturation >4% = HIGH
RISK
O >25 shuttles and <4% desaturation
- full cardiopulmonary exercise testing
VO2max <15ml/kg/min = HIGH RISK
VO2max>15ml/kg/min = AVERAGE RISK

27. O ABG
- Hypoxaemia( PaO2< 60mmHg)
- Hypercapnia ( PaCO2> 50 mmHg)
- Increased perioperative complications

28. OPulmonary arterial compliance
- Clamping the Pulmonary artery supplying the
diseased lung
- Main pulmonary arterial pressure> 40 mmHg
- PaCO2> 60mmHg
- PaO2< 45mmHg
- Survival unlikely

29. Physiological changes in respiratory
system in OLA
- Patients are usaually placed in lateral
decubitus position
- Main phases
- spontaneously breathing patient
- Total lung ventilation-
paralysed/chest closed
- Total lung ventilation- paralysed/
chest open
- One lung ventilation

30. Spontaneous breathing

31. Paralysed with closed chest- Total lung ventilation
- Gravity causes 60% blood flow
to be directed to dependent
lung
- Pushing up of diaphragm/
paralysis of diaphragm/
Mediastinal contents on
dependent lung causes reduced
compliance and FRC of
dependent lung with
PREFERENTIAL VENTILATION
of non-dependent lung.

32. OPEN CHEST- Total lung ventilation
Once chest is open,
- Restricting forces of chest wall on non-
dependent lung are removed
- More compliant and easily ventilated( over
ventilated)
- Reduced perfusion
- Leads to a further increase in V/Q
mismatch

33. OPEN CHEST- NON DEPENDENT LUNG
COLLAPSED

34. During OLA
- Non dependent lung is not ventilated
- A portion of blood flow remains
- Shunting
- Risk of Hypoxaemia
- If minute ventilation remains constant-
slow build up of CO2
- Several mechanisms are contributing to
reduce this shunt

35. Factors causing a reduced blood supply to Non-
dependent lung in OLA
1. Gravity- 60% blood flow to dependent
lung
2. Collapse and surgical manipulation
causes a mechanical obstruction to blood
flow
3. Hypoxic pulmonary vasoconstriction
- extra-alveolar pulmonary arterioles
- occurs when there is a reduction in
alveolar
Po2 to 4 - 8 kPa

36. O Mechanism of HPV - not fully understood
- either a direct response to regional alveolar
and mixed venous hypoxia
- or due to the release of vasoactive substances
during hypoxia
- Results in a 50% reduction in blood flow to
non depedendent lung
- Blood flow- 20% of total pulmonary flow

37. O Anaesthetic factors affecting HPV
- Inhaled anaesthetic agents with MAC< 1
have minimal effects on HPV
- Isoflurane – 21% reduction of HPV at
MAC 1
- N2O- reduce HPV by 10%
- Inspired O2 ?????

38. O Intravenous agents
- No effect with propofol/TPS/Ketamine or
fentanyl
O Systemic and pulmonary vasodilators
inhibit HPV
O Vasoconstrictors????

39. O Vasoconstrictors
- vasoconstrict vessels in dependent lung
with diversion of flow to non dependent
lung
- Increases shunt fraction
- Dopamine acts as a pulmonary
vasoconstrictor
- has a minimal effect
- May be suitable as a vasoconstrictor
agent if needed

40. O PEEP
- Applied to Dependent lung causes
increased pulmonary arterial pressures and
diversion of blood flow to non dependent
lung
- Increased shunt

41. Conduct of anaesthesia
O Targets
- Reduce airway reflexes and irritability
- Reduce inhibition of HPV
- Maitanain cardiovascular stability with
judicial fluid management and use of
vasoconstrictors
- Standard monitoring with IBP/CVP and
pressure-volume loop monitoring

42. O GA with maintenance with inhalational
agents
O GA with TIVA ( not found to be more
effective)
O GA with thoracic epidurals for analgesia
- Reduced opiod need
- A large Meta analysis has shown reduced
atelectasis/ chest infections and overall
pulmonary complications
- Paravertebral bolcks+/- intercostal blocks

43. O Continue Double lung ventilation as much as
possible
O During OLV- TV 5-6ml/Kg/ FiO2 0.5-1.0
if Air way pressures>35 cmH2O OR
Plateau pressures> 25 cmH2O
Increase RR by 20%
maintain normal PaCO2 OR allow
permissive hypercapnia to reduce barotrauma
PEEP – 5cmH2O ( Avoid in COPD
pts)
Volume or pressure controlled(
Pressure control in Lung bullae/cysts/
pneumonectomies)
O Management of Hypoxaemia

44. Management of Hypoxaemia during OLV
O Systematic approach
1. Reduced delivery of oxygen
- Check anaesthetic machine/ ventilator/
breathing system

45. - Check position of DLT with ausculation or
preferably with fiberoptic bronchoscopy
- Suck out secretions
- To ventilated lung
- Apply recruietment maneuvers
- Apply PEEP of 5cmH2O

46. - To nonventilated lung
- apply recruitement maneuvers
- apply a CPAP OF 1-2 cmH2O
- Intermittent reinflation
- Partial ventilation with O2
insufflation/ High frequency ventilation
- mechanical restriction of blood
flow to the lung

47. - Maintain cardiac output (
Vasoconstrictors/ reducing volatile agent
MAC=/< 1/ withholding vasodilators)
- Switch to double lung ventilation if
severe/refractory hypoxaemia persists

48. Newer concepts
O selective administration of the vasodilator
prostaglandin E1 to the ventilated lung or
a nitric oxide synthase inhibitor to a
hypoxic lobe results in improved
redistribution of pulmonary blood flow in
animal models

49. O Selective administration of nitric oxide
(NO) alone to the ventilated lung was not
shown to be of benefit in humans
O The combination of NO (20 ppm) to the
nonventilated lung and an intravenous
infusion of almitrene, which enhances
HPV, restores Pao2 values during OLV in
humans to essentially the same levels as
during two-lung ventilation

50. O the combination of nitric oxide and other
pulmonary vasoconstrictors such as
phenylephrine
( shown to improve oxygenation in
ventilated intensive care unit patients with
ARDS and this may have applications in
OLV)

51. REFERENCES
O ATOTW 145. One Lung Ventilation,
03/08/2009
O Millers anaesthesia; 7th edition; Thoracic
anaesthesia
O Hypoxaemia in one lung ventilation:
Continuing Education in Anaesthesia,
Critical Care & Pain Volume 10 Number 4
2010