PRESENTATION , WHICH MAY HELP REVISING IMPORTANT FACTS IN CLINICAL PRACTICE. INCLUDING NEEDS , COMPLICATION, EXPERTISE.

1. Anaesthetic concern for one lung
ventilation
BY- DR.BHUSHAN KINGE,
M.D.
IMS – BHU , VARANASI

2. One Lung Ventilation (OLV) is a technique that
allows isolation of the individual lungs and each
lung functioning independently by preparation of
the airway under anaesthesia.
One Lung Ventilation first in 1931 by Gale and
Waters  complex lung resection surgery. He used
a single-light tube that was inserted into the right or
left main bronchus.

3. Objectives
• Indication/contraindication of OLV
• Physiology changes of OLV
• Selection of the methods for OLV
• Management of common problems
associated with OLV.

4. Introduction
• One-lung ventilation, OLV, means separation of
the two lungs and each lung functioning
independently by preparation of the airway
• OLV provides:
– Protection of healthy lung from infected/bleeding one
– Diversion of ventilation from damaged airway or lung
– Improved exposure of surgical field
• OLV causes:
– More manipulation of airway, more damage
– Significant physiologic change and easily development
of hypoxemia

5. Absolute indication for OLV
– Isolation of one lung from the other to avoid spillage or
contamination
• Infection
• Massive hemorrhage
– Control of the distribution of ventilation
• Bronchopleural / - cutaneous fistula
• Surgical opening of a major conducting airway
• giant unilateral lung cyst or bulla
• Tracheobronchial tree disruption
• Life-threatening hypoxemia due to unilateral lung disease
– Unilateral bronchopulmonary lavage

6. Relative indication
– Surgical exposure ( high priority)
• Thoracic aortic aneurysm
• Pneumonectomy
• Upper lobectomy
• Mediastinal exposure
• Thoracoscopy
– Surgical exposure (low priority)
• Middle and lower lobectomies and subsegmental resections
• Esophageal surgery
• Thoracic spine procedure
• Minimal invasive cardiac surgery .
– Postcardiopulmonary bypass status after removal of totally
occluding chronic unilateral pulmonary emboli.
– Severe hypoxemia due to unilateral lung disease.

7. Two-lung ventilation and OLV

8. Lateral Decubitus Position
Patient remains in this position to facilitate Thoracic surgery.
The lower and upper lung in this position is termed dependent
and non-dependent respectively.
There is considerable V/Q mismatch as there is greater
ventilation but less perfusion to the non-dependent lung and
converse to the dependent lung.
The blood flow is determined by the gravity.

9. Lateral Decubitus Position
• The good ventilation of the upper lung is due to
open chest while the poor ventilation of the
lower lung is due to compression of the lung by
mediastinum, diaphragm and chest wall
compression.

10. Diagrammatic representation of the V/Q relationship in
patient with open chest in LDP

11. BLOOD FLOW DISTRIBUTION DURING OLV
 The main physiological changes in OLV is the redistribution of lung
perfusion between the ventilated (dependent) and blocked
(nondependent) lung
 The major determinants of blood flow distribution between both lungs
are: Gravity, Amount of lung disease, Magnitude of HPV, Surgical
interference (Nondependent Lung) Ventilatatory mode (dependent Lung)

12. During one-lung ventilation
Greater decrease in oxygenation than during two-lung
ventilation in LDP due to an obligatory Rt-Lt
transpulmonary shunt through the nonventilated
nondependent lung. Consequently, lower PaO2 & larger
P(A-a) O2 gradient.
Usually carbon dioxide elimination is not a problem;
retention of CO2 by blood traversing the nonventilated
lung slightly exceeds the increased elimination of CO2
from blood traversing the ventilated lung, and the PaCO2
will usually slowly increase and P(A-a) CO2 decreases .

13. Hypoxic pulmonary vasoconstriction
• HPV is a physiological response of the lung to alveolar
hypoxia, which redistributes pulmonary blood flow from
areas of low oxygen partial pressure to areas of high
oxygen availability.
• The mechanism of HPV is not completely understood.
Vasoactive substances released by hypoxia or hypoxia itself
(activating K+, Ca++ and TRP channels) cause pulmonary
artery smooth muscle contraction.

14. table summarizing the V/Q changes in
LDP
Dependent Lung Non-dependent Lung
Ventilation Reduced Increased
Perfusion Increased Reduced
Pulmonary blood
flow
80% 20%

15. HPV
• 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.
• HPV is effective only when there are normoxic areas
of the lung available to receive the diverted blood
flow

16. HPV
• HPV is inhibited directly by
volatile anesthetics (less
with N20), vasodilators
(NTG, SNP, NO,
dobutamine, ß2-agonist),
increased PVR (MS, MI, PE)
and hypocapnia.
• HPV is indirectly inhibited
by PEEP; vasoconstrictor
drugs (epinephrine,
norepinephrine,
phenylephrine, dopamine)
constrict normoxic lung
vessels preferentially.

17. Gravity and V-Q
• Upright LDP

18. Physiology of LDP
Awake/closed chest Anesthetized .
V Q V Q V Q
ND      
D      

19. Shunt and OLV
• Physiological (postpulmonary) shunt
• About 2-5% CO,
• Accounting for normal A-aD02, 10-15 mmHg
• Including drainages from
– Thebesian veins of the heart
– The pulmonary bronchial veins
– Mediastinal and pleural veins
• Transpulmonary shunt increased due to continued
perfusion of the atelectatic lung and A-aD02 may
increase.

20. Cardiac output and OLV
• Decreased CO may reduce SvO2 and thus impair
SpO2 in presence of significant shunt
– Hypovolemia
– Compression of heart or great vessels
– Thoracic epidural sympathetic blockade
– Air trapping and high PEEP
• Increased CO increases PA pressures which
increases perfusion of the non-ventilated lung →
increase of shunt fraction

21. Methods of OLV
• Double-lumen endotracheal tube, DLT
• Single-lumen ET with a built-in bronchial
blocker, Univent Tube
• Single-lumen ET with an isolated bronchial
blocker
– Arndt (wire-guided) endobronchial blocker set
– Balloon-tipped luminal catheters
• Endobronchial intubation of a single-lumen ET

22. DLT
• Type:
– Carlens, a left-sided + a carinal hook
– White, a right-sided Carlens tube
– Bryce-Smith, no hook but a slotted cuff/Rt
– Robertshaw, most widely used
• All have two lumina/cuffs, one terminating
in the trachea and the other in the mainstem
bronchus
• Right-sided or left-sided available
• Robertshaw -Available size: 41,39, 37, 35, 28
French (ID=6.5, 6.0, 5.5, 5.0 and 4.5 mm
respectively).

23. DIFFERENT TYPES OF DLT

24. Left DLT…
• Most commonly used
• The bronchial lumen is longer, and a simple round
opening and symmetric cuff.
• Better margin of safety than Rt DLT
• Easy to apply suction and/or CPAP to either lung
• Easy to deflate lung
• Lower bronchial cuff volumes and pressures
• Can be used
– Left lung isolation:
clamp bronchial +
ventilate/ tracheal lumen
– Right lung isolation:
clamp tracheal +
ventilate/bronchial lumen

25. DLT
• More difficult to insert (size and curve, cuff)
• Risk of tube change and airway damage if kept in
position for post-op ventilation
• Contraindication:
– Presence of lesion along DLT pathway
– Difficult/impossible conventional direct vision intubation
– Critically ill patients with single lumen tube in situ who
cannot tolerate even a short period of off mechanical
ventilation
– Full stomach or high risk of aspiration
– Patients, too small (<25-35kg) or too young (< 8 yrs)

26. TO ENSURE CORRECT POSITION OF DLT CLINICALLY
 Breath sounds are Normal (not diminished) & follow the expected
unilateral pattern with unilateral clamping
 The chest rises and falls in accordance with the breath sounds
 The ventilated lung feels reasonably compliant
 No leaks are present
 Respiratory gas moisture appears and disappears with each tidal
ventilation

27. Complications of DLT
 Impediment to arterial oxygenation
 Tracheobronchial tree disruption, due to
-excessive volume and pressure in bronchial balloon
-inappropriate tube size
-malpositioning
 Traumatic laryngitis (hook)
 Inadvertent suturing of the DLT

28. Relative Contraindications to Use of DLT
 Full stomach (risk of aspiration);
 Lesions (stricture, tumor) along the pathway of DLT (may be traumatized);
 Small patients;
 Anticipated difficult intubation;
 Extremely critically ill patients who have a single-lumen tube already in place
and who will not tolerate being taken off mechanical ventilation and PEEP
even for a short time;
 Patients having some combination of these problems.
Under these circumstances, it is still possible to separate the
lungs by :
- Using a single-lumen tube + FOB placement of a bronchial blocker; or
- FOB placement of a single-lumen tube in a main stem bronchus.

29. Univent Tube
• Developed by Dr. Inoue
• Movable blocker shaft in
external lumen of a single-lumen
ET tube
• Easier to insert and properly
position than DLT (diff airway, C-s
injury, pedi or critical pts)
• No need to change the tube for
postop ventilation
• Selective blockade of some lobes
of the lung .
• Suction and delivery CPAP to the
blocked lung.

30. Univent Tube
• Slow deflation (need suction)
and inflation .
• Blockage of bronchial blocker
lumen.
• Higher endobronchial cuff
volumes +pressure (just-seal
volume recommended).
• Higher rate of intraoperative
leak in the blocker cuff.
• Higher failure rate if the blocker
advanced blindly.

31. Univent Tube

32. Arndt Endobronchial Blocker set
• Invented by Dr. Arndt, an anesthesiologist
• better for difficult intubation, pre-existing ETT and
postop ventilation needed
• Requires ETT > or = 8.0 mm
• Similar problems as Univent
• Inability to suction or ventilate the blocked lung

33. Arndt endobronchial blocker
[Wire guided Endobronchial Blocker (WEB)]

34. Cohen Flexitip Endobronchial Blocker

35. Other methods of OLV
• Single-lumen ETT with a balloon-tipped catheter
– Including Fogarty embolectomy catheter, Foley, and Swan-
Ganz catheter (children < 10 kg)
– Not reliable and may be more time-consuming
– Inability to suction or ventilate the blocked lung
• Endobronchial intubation of single-lumen ETT
– The easiest and quickest way of separating one lung from
the other bleeding one, esp. from left lung
– More often used for paediatric patients
– More likely to cause serious hypoxemia or severe
bronchial damage

36. Broncho-Cath CPAP system

37. Preoperative assessment
• Assess ability to withstand OLV & possible lung
resection.
• In lung surgery, assess each patient as if for lung
resection.
• Possibility of extensive surgical manipulation,
significant blood loss, postoperative impaired
function of remaining lung, asssociated pnuemonia,
atelectasis.

38. Preoperative Measures
Patient should be in optimal condition for surgery
Cessation of smoking
Bronchial dilatation: Beta-2 agonists, Theophylline, Steroids
Loosening the secretions: Airway hydration, Systemic hydration,
Mucolytic and expectorant drugs
Removal of Secretions: Postural drainage, Coughing, Chest
physiotherapy
Increase Patient Participation: Psychological preparation, Educate
and motivate for secretion removal measures and exercise
(Incentive spirometry)

39. Poor candidate for OLV
• Limited exercise tolerence
• Cardiac pathology(moderate MS, MR)
• Breathlessness at rest
• Moderate to severe pulmonary hypertension
• Cor pulmonale

40. Indicator of High risk for perioperative
complications on spirometry
• FEV1 < 50% predicted value or less than 2
litres.
• FVC < 50% predicted value .
• MBC <50% predicted value .
• RV/TLC <50% predicted value .

41. ABG ANALYSIS
Preoperative PaO2 < 60 mm Hg.
Preoperative paCO2 > 50 mm Hg.
these conditions are more likely to have
perioperative hypoxia and hypercapnea during
OLV.

42. Assessment of indidual lung functions
• For pt. with boarderline respiratory function.
• Perfusion/ventilation of indidual lung is assessed by
radioisotope Xe 133, Tc99 scan.
• Predicted postoperative FEV1 < 40% OR < 0.850
LITRE is associated with more risk of respiratory
failure.

43. Risk for postoperative ventilation
• PATIENT FACTORS –
• Current smoker
• ASA STATUS> 2
• Age more than 70 yrs in COPD pts.
• COPD with exercise intolerence

44. Risk for postoperative ventilation
• Surgery dependant factors –
• Duration more than 4 hrs
• Emergency procedure
• Reexploration.

45. Risk for postoperative ventilation
• Nunn milledge crieteria-
FEV1 < 1litre, low paO2, normal paCO2- may
need prolonged oxygen supplymentation.
FEV1 < 1 Litre, low paO2, high paCO2- may need
postoperative ventilation.

46. Risk for postoperative ventilation
• Based on spirometry-
• Predicted FEV1 < 50 % or < 2 litres
• Predicted FVC < 50 %
• Predicted MVV < 50 % OR < 50 litre/ min
• Predicted DLCO2 < 50 % predicted
• Predicted RV/TLC > 50 %

47. technique of choice
• GA with controlled ventilation is method of choice.
• GA with thoracic epidural analgesia, intercostal
block, paravertebral block.
• Aim is to –
suppress airway reflexes, irritability,
Decrease inhibition of HPV,
maintain the cardiovascular status.
Maintain both lung ventilation as far as possible.

48. Management of OLV
– Maintain two-lung ventilation as long as possible.
– Prior switching to OLV give 100 % oxygen.
– Start OLV with 100% O2 then start backing off the FiO2 if
saturations are OK
– Manual ventilation for the first few minutes of OLV to get a
sense of pulmonary compliance / resistance
– Be attentive to inspiratory pressures and tidal volumes and
adjust the ventilator to optimize oxygenation and alveolar
ventilation, with minimal barotrauma
– Look at the surgical field to see if the non-dependent lung
is collapsed

49. Management of OLV
– Tidal volume = 8-10 ml/kg
– Adjust RR (increasing 20-30%) to keep PaCO2 = 40
mmHg approx.
– No PEEP (or very low PEEP, < 5 cm H2O)
– Continuous monitoring of oxygenation and
ventilation (SpO2, ABG and ET CO2) .

50. hypoxemia in OLV
– Mechanical failure of O2 supply or airway
blockade.
– Hypoventilation.
– Resorption of residual O2 from the clamped lung.
– Factors that decrease SvO2 (CO, O2
consumption).

51. Management of hypoxemia during OLV
– FiO2 = 1.0
– Manual ventilation
– Check DLT position with FOB
– Check hemodynamic status
– CPAP (5-10 cm H2O, 5 L/min) to nondependent
lung.
– PEEP (5-10 cm H2O) to dependent lung .
– Intermittent two-lung ventilation.
– Temporary Clamp pulmonary artery of non-ventilated
lung .

52. Management of hypoxemia during OLV
Pulmonary edema in non ventiated lung-
• Intraoperative collapse .
• handling of lung tissue.
• Imaired capillary function in postoperatve
period.
• Needs Judicious use of perioperative fluid and
vasopressor.

53. Management of hypoxemia during OLV
• Ability to maintain OLV in lateral decubitus
should be checked prior to start of surgery for
feaesibilit
• airway pressure is to be monitored closely.
• Intermittent inflation of collapsed lung may be
necessary sometimes.

54. OLV postoperative complications
• Oedema of operative site
• Collapse
• Consolidation.
• Retention of sputum.
• Inadequate pain relief limiting adequate chest
expansion
May need diuretics , high peep, higher fiO2,
inotropic support.

55. OLV postoperative complications
• Arrhythmia,
• RVF,
• cardiac herniation,
• cardiovascular hemorrhage.

56. Postoperative period
• Before resuming both lung ventilation do suction and
fully inflate lungs.
• Postopearative x-ray is advised to rules out pneumo,
hemothorax, collapse, misplaced drains.
• Adequate pain relief, ability to cough, moisturised
air/ oxygen therapy, breathing exercises ,
physiotherapy are essentially appropriate to prevent
complications.
• judicious fluid therapy - Positive fluid balance is kept
below 20 ml/kg.

57. Thank you..