one lung ventillation, problem based learning

ONE-LUNG VENTILATION(OLV):
TECHNIQUE AND ANAESTHETIC
CONSIDERATIONS
Dr Varun Kumar Varshney

•Define one lung ventillation?

INTRODUCTION
One-lung ventilation, OLV, means separation of
the two lungs and each lung functioning
independently by preparation of the airway
1950 –Carlens design of DLT use for lung surgery.
1960- Robertshaw introduced design
modifications for separate left and right-sided
DLTs.
1980- Disposable DLTs made of PVC based on
design of Robertshaw DLT.

 Requires greater skill of the anesthesia team
because of
oDifficult to place lung isolation equipment
oDifficulty to overcome hypoxic pulmonary
vasoconstriction in dependent lung
oPatient population is comparably “sicker”

•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
•Dependent Lung or Down Lung
• The lung that is ventilated
•Non-dependent Lung or Up Lung
• The lung that is collapsed to facilitate the surgery

•Indication of one lung ventillation?

ABSOLUTE INDICATION FOR OLV
•Isolation of each lung to prevent
contamination of a healthy
• Infection (abscess, infected cyst)
• Massive hemorrhage
•Control of the distribution of ventilation to
only one lung
• Bronchopleural fistula
• Bronchopleural cutaneous fistula
• Unilateral cyst or bullae
• Major bronchial disruption or trauma
•Unilateral bronchopulmonary lavage
•Video assisted thoracoscopic surgery(VATS)

RELATIVE INDICATION
•Surgical exposure ( high priority)
• Thoracic aortic aneurysm
• Pneumonectomy
• Lung volume reduction
• Mininmal invasive cardiac surgery
• Upper lobectomy
•Surgical exposure (low priority)
•Middle and lower lobectomies
•Esophageal surgery
•Mediastinal mass resection, thymectomy
•Bilateral sympathectomies

OLV Devices
OLV is achieved by either;
Double lumen ETT (DLT)
Bronchial blocker
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 tube
• Endobronchial intubation of a single-lumen ET

• Related Anatomy of tracheo-bronchial
tree?

Anatomy of the
Tracheobronchial Tree

Double Lumen Tube(DLT)
RUL, right upper lobe; LUL, left upper lobe

• TYPES OF DLT?
•MOST COMMONLY USED DLT?
•SIZES AVAILABLE?

DLT Types
•Type:
• Carlens, a left-sided + a carinal
hook
• White, a right-sided Carlens
tube
• Bryce-Smith, no hook but a
slotted cuff
• Robertshaw, most widely used
• All have two lumen and cuffs, one
terminating in the trachea and the
other in the mainstem bronchus
• Right-sided or left-sided available
• Available size: 41,39, 37, 35,
32,28,28French (ID=6.5, 6.0, 5.5,
5.0 and 4.5 mm respectively)

Basic pattern of a Right-Sided DLT

•COMPARE DIFFERENT TYPES OF DLT?

Different types of DLT
Carlens White Bryce Smith Robertshaw
Lumen
Hook
+ + - -
Side
Lt Rt Lt & Rt Lt & Rt

•DIFFERENCE B/W RIGHT SIDE AND LEFT
SIDE DLT?

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 for:
• Left lung isolation: clamp bronchial + ventilate/ tracheal lumen
• Right lung isolation: clamp tracheal + ventilate/bronchial
lumen
• More difficult to insert (size and curve, cuff)
• Risk of tube change and airway damage if kept in position for
post-op ventilation

•Indication for RT sided DLT?

Right DLT
• Left –sided DLT is used more commonly for most elective
thoracic procedures ,
Following are specific clinical situation in which
Right –sided DLT is indicated :
 Distorted Anatomy of the Entrance of Left Mainstem
Bronchus
External or intraluminal tumor compression
Descending thoracic aortic aneurysm
Site of Surgery Involving the Left Mainstem Bronchus
Left lung transplantation
Left –sided tracheobronchial disruption
Left –sided pneumonectomy
Left-sided sleeve resection

DLT Placement
•Prepare and check tube
Ensure cuff inflates and deflates
•Lubricate tube
•Insert tube with distal concave curvature facing
anteriorly
•Remove stylet once through the vocal cords
•Rotate tube 90 degrees (in direction of desired
lung)
•Advancement of tube ceases when resistance is
encountered. Average lip line is 29 ± 2 cm.
•*If a carinal hook is present, must watch hook go
through cords to avoid trauma to them.

•CONFIRMATION OF PROPER
PLACEMENT of LEFT sided DLT?

Check for placement of DLT
•Check for placement by auscultation
•3 STEP METHOD
1- Tracheal tube inflated-confirm b/l ventillation
2- tracheal lumen clamped, port distal to clamp
opened,inflate bronchial cuff- auscultate to confirm
unilateral ventillation.
3-Clamp removed,port closed-b/l breath sound.

Even if the DLT is thought to be properly
positioned by clinical signs, subsequent FOB
may reveal an incidence of malposition (38 -78
%)

•Importance of fibreoptic bronchoscope?

Check for placement of DLT
• Checking tube placement with the Fiberoptic
Bronchoscope
• Several situations exist where auscultation maneuvers are
impossible (patient is prepped and draped), or when they do
not provide reliable information (preexisting lung disease so
that breath sounds are not very audible, or if the tube is
only slightly malpositioned)
• The double-lumen tube's precise position can be most
reliably determined with the fiberoptic bronchoscope
• In patients with double-lumen tubes whose position seemed
appropriate to auscultations, 48% had some degree of
malposition. So always check position with fiberoptic
• After advancing the fiberoptic scope through the “tracheal”
tube you should see the “bronchial blue balloon” in a semi
lunar shape, just peeking out of the bronchus

one lung ventillation, problem based learning

•Other method to check DLT Placement?

Other Methods to Check DLT Position
Chest radiograph;
may be more useful than conventional auscultation and
clamping in some patients, but it is always less precise than FOB.
The DLT must have radiopaque markers at the end of Rt and Lt
lumina.
Comparison of capnography;
waveform and ETCO2 from each lumen may reveal a
marked discrepancy (different degree of ventilation).
Surgeon;
may be able to palpate, redirect or assist in changing DLT
position from within the chest (by deflecting the DLT away from
the wrong lung, etc..).

Guide for Length and Size of DLT
Length of tube: For 170 cm height, tube depth of 29 cm
For every 10 cm height change , 1 cm depth change
Patient characteristics Tube size (Fr gauge)
Tracheal width (mm):
18
16
15
14
41
39
37
35
Patient height
4’ 6”-5’5”
5’5”-5’10”
5’11”-6’4”
35-37
37-39
39-41
Patient age (year)
13-14
12
10
8
35
32
28 (lt only)
26 (lt only)

Adequacy for Sealing (Air Bubble test)

Complications of DLT
impediment to arterial oxygenation for OLV
tracheobronchial tree disruption, due to
-excessive volume and pressure in bronchial balloon
-inappropriate tube size
-malposition
traumatic laryngitis (hook)
inadvertent suturing of the DLT

•How to avoid Tracheobronchial tree
Disruption?

To avoid Tracheobronchial tree
Disruption
Be cautious in patients with bronchial wall abnormalities.
Pick an appropriately sized tube.
Be sure that tube is not malpositioned ; Use FOB.
Avoid overinflation of endobronchial cuff.
Deflate endobronchial cuff during turning.
Inflate endobronchial cuff slowly.
Inflate endobronchial cuff with inspired gases.
Do not allow tube to move during turning.

Contraindications
• Presence of lesion(stricture, tumor) 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 (< 8-12 yrs)
• 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.

•Advantage/Disadvantage of DLT?

Advantages of DLT
Relatively easy to place
Allow conversion back and forth from OLV to two-lung
ventilation
Allow suctioning of both lungs individually
Allow CPAP to be applied to the non-dependent lung
Allow PEEP to be applied to the dependent lung
Disadvantages of DLT
Cannot take patient to PACU or the Unit
Must be changed out for a regular ETT if post-op ventilation
Correct positioning is dependent on appropriate size for
height of patient

Bronchial Blockers
(With Single-Lumen Endotracheal Tubes)
Lung separation can be effectively achieved with the
use of a single-lumen endotracheal tube and a FOB
placed bronchial blocker.
Often necessary in children as DLTs are too large to
be used in them. The smallest DLT available is a left-
sided 26 Fr tube, which may be used in patients 8 -12
years old and weighing 25 -35 kg.
Balloon-tipped luminal catheters have the
advantage of allowing suctioning and injection of
oxygen down the central lumen.

•Different Types of bronchial blockers?

Types of bronchial blockers
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
Cohen Flexitip Endobronchial Blocker
BB independent of a single-lumen tube

Univent Bronchial Blocker System

Univent Tubes
• Endotracheal intubation can be performed in the
conventional manner, just like a single lumen
endotracheal tube
• One-lung ventilation can be achieved by placement of
the blocker to either the left or right lung, or to lung
segments
• Blocked lung can be collapsed by aspirating air through
the lumen of the blocker shaft
• The blocker can be retracted into its pocket to facilitate
post-operative ventilation

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,
Cervico-spinal injury, pediatric or
critical patients)
• No need to change the tube for
post-op ventilation
• Selective blockade of some lobes
of the lung
• Suction and delivery CPAP to the
blocked lung

Univent Tube…
• Slow deflation (need suction)
and inflation (short PPV or jet
ventilation)
• 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

Steps of FOB-aided method of positioning the Univent
bronchial blocker in lt main stem bronchus
One- or two-lung ventilation is achieved simply by inflating or
deflating, respectively, the bronchial blocker balloon

•Advantage of bronchial blocker over
DLT?

Advantages of the Univent Bronchial
Blocker Tube ( Relative to DLT )
1. Easier to insert and properly position.
2. Can be properly positioned during continuous
ventilation and in the lateral decubitus position.
3. No need to change the tube when turning from the
supine to prone position or for postoperative
mechanical ventilation.
4. Selective blockade of some lobes of each lung.
5. Possible to apply CPAP to nonventilated operative
lung.

•Limitations to the Use of Univent Bronchial
Blocker ?

Limitations to the Use of Univent
Bronchial Blocker
LIMITATION SOLUTION
1. Slow inflation time (a) Deflate BB cuff and administer +ve pressure breath
through the main single lumen;
(b) carefully administer one short high pressure (20–30 psi)
jet ventilation
2. Slow deflation time (a) Deflate BB cuff and compress and evacuate the lung
through the main single lumen;
(b) apply suction to BB lumen
3. Blockage of BB
lumen
( blood, pus,..)
Suction, stylet, and then suction
4. High-pressure cuff Use just-seal volume of air
5. Leak in BB cuff Make sure BB cuff is subcarinal, increase inflation volume,
rearrange surgical field

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

Arndt Endobronchial Blocker set

Wire-Guided Endobronchial
Blockers
• Invented by Dr. Arndt, an
anesthesiologist so Arndt
endobronchial blocker
• Ideal for difficult intubation,
pre-existing ETT and postop
ventilation needed
• Requires ETT ≥ 8.0 mm
• Similar problems as Univent
• Inability to suction or
ventilate the blocked lung
• Available sizes
• Adult 9 Fr
• Pediatric 5 Fr

Wire-Guided Endobronchial
Blockers

•Indication of Wire Guided endobrochial
Blockers?

Indications for Wire-Guided
Endobronchial Blockers vs. DLT
Critically ill patients
Rapid sequence induction(RSI)
Known and unknown difficult airway
Postoperative intubation
Small adult and pediatric patients
Obese adults

Advantages of WEBs
Quickly and precisely navigate the airway
The pediatric bronchoscope acts as a guide, allowing
the endobronchial blocker to be advanced over it into
the correct position.
In addition, the wire-guided endobronchial blocker
allows one-lung ventilation with a single-lumen
endotracheal tube
• Thus, used in places of DLT or a Univent endotracheal tube
• Allows OLV in the critically ill patient in whom reintubation
may be difficult or impossible
• Unnecessary to convert from a conventional DLT to a single-
lumen tube at the end of surgery

Disadvantages of WEBs
•Satisfactory bronchial seal and lung separation are
sometimes difficult to achieve
•The “blocked” lung collapses slowly (and sometimes
incompletely)
•The balloon may become dislodged during surgery and
enter the trachea proper, causing a complete airway
obstruction

•Cohen Flexitip Endobronchial Blocker?

Cohen Flexitip Endobronchial Blocker

Disadvantages of a bronchial
blockers as compared with DLT?

Disadvantages of a blocker that is
independent of the single-lumen tube as
compared with DLT
inability to suction and/or to ventilate the lung distal
to the blocker.
increased placement time.
the definite need for a fiberoptic or rigid
bronchoscope.
if bronchial blocker backs out into the trachea, the
seal between the two lungs will be lost and the
trachea will be at least partially obstructed by the
blocker, and ventilation will be greatly impaired.

The EZ-Blocker
•The EZ-blocker is a new BB that has a Y-shaped
distal end.
•The peculiar characteristic of this device is that
both distal ends are fitted with an inflatable cuff
and a center hollow channel in each end.
•Therefore each inflatable balloon can be placed on
the right or left mainstem bronchus, respectively.
•The shape of this balloon is spherical and there is
only one size available at the present time, 7F.

DLT is the method of choice for lung separation in most adult
patients. The precise location can be determined by FOB .
In situations where insertion of a DLT may be difficult and/or
dangerous, separating the lungs is achieved either with a single-
lumen tube alone or in combination with a bronchial blocker (e.g.,
the Univent tube).
Therefore,
regardless of what method of lung separation chosen, there is a
real need of a small-diameter FOB (for checking the position of
the DLT, placing a single-lumen tube in a mainstem bronchus,
and placing a bronchial blocker) .
Summary of OLV devices

•Complication of one lung ventillation?

Complications of One Lung
Ventilation
All difficult airway complications
Injury to lips, mouth, teeth
Injury to airway mucosa from stylet
Bronchial Rupture
Decreased saturation
HPV
Inability to isolate lung

Physiology of OLV
(Arterial Oxygenation and Carbon Dioxide Elimination)
Blood passing
through:
Non Ventilated Lung,Non Ventilated Lung,
retains CO2 and does
not take O2.
Over VentilatedOver Ventilated
Lung,Lung, gives off more
than a normal
amount of CO2 but
cannot take up a
proportionately
increased amount of
O2

Thus, during one-lung ventilation
 more decreased 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
 usually carbon dioxide elimination is not a problem; but
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 .

Two-lung ventilation versus OLV
during OLV, the nonventilated lung has some blood flow and
therefore has an obligatory shunt, which is not present during two-
lung ventilation & is the most important reason for increased P(A-

Factors influencing pulmonary
perfusion
85
Many factors contribute to
the lung perfusion,
•hypoxic pulmonary
vasoconstriction (HPV)
•gravity,
•amount of lung disease,
•surgical interference in
nondependent lung,
•ventilation mode in
dependent lung
The principle physiologic change of OLV is the redistribution of
lung perfusion between the ventilated (dependent) and blocked
(nondependent) lung.

1. in LDP ,ventilated dependent lung
usually has a reduced volume resulting
from combined factors of induction of
anaesthesia and circumferential
compression by mediastinum,
abdominal contents, and suboptimal
positioning effects (rolls, packs,
supports).
2. absorption atelectasis can occur in
regions with low V/Q when they are
exposed to high FIO2 .
3. difficulty in secretion removal .
4.maintaining the LDP for prolonged
periods may cause fluid to transude
into the dependent lung and cause
further decrease in lung volume and
increase in airway closure.
Hypoxic compartment may develop intraoperatively for several
reasons:

Surgical interference
(compression ,retraction and ligation of pulmonary vessels
during pulmonary resection) of the nondependent lung may
further passively reduce its blood flow.
Mode of ventilation of dependent lung
•If hyperventilated, lead to decrease in PaCO2 that causes
decrease in HPV
•Excessive increase of AWP (PEEP or VT): increase dependent
PVR and nondependent lung blood flow.
•Increase FiO2 causes
• Vasodialatation in dependent lung, augmenting HPV in
nondependent lung
• but ,may cause absorption atelectasis in regions that have
low V/Q ratios

•Hypoxic pulmonary vasoconstriction?

Hypoxic Pulmonary Vasoconstriction
(HPV)
•HPV, a physiological local response of
pulmonary vascular smooth muscle (PVSM) to
alveolar hypoxia,
•decreases blood flow to the area of lung where
a low alveolar oxygen pressure is sensed and
redistributes pulmonary blood flow from areas
of low oxygen partial pressure to areas of high
oxygen availability.
89

•Intrinsic response of lung, no neuronal control,
immediately present in transplanted lung.
•The mechanism of HPV 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 vasoconstrict in
response to hypoxia, but greatest effect is to small
pumonary arteries

Hypoxic Pulmonary Vasoconstriction
(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.
•But effective only when there are normoxic areas
of the lung available to receive the diverted blood
flow
93

Factors affecting regional HPV
• HPV is inhibited directly by
volatile anesthetics (not
N20), vasodilators (NTG,
SNP, NO, dobutamine, many
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

Other Causes of Hypoxaemia During
OLV
Failure of the oxygen supply.
Gross hypoventilation of the dependent lung.
Blockage of the dependent lung airway lumen e.g.
by secretions
Malposition of the DLT
Resorption of residual O2 from the clamped lung
Decrease of PvO2 (decreased cardiac output,
increased oxygen consumption [excessive sympathetic
nervous system stimulation, hyperthermia, shivering)

•Management of Hypoxia during OLV?

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, most effective
•PEEP (5-10 cm H2O) to dependent lung, least
effective
•Intermittent two-lung ventilation
•Clamp pulmonary artery

Summary
•OLV widely used in cardiothoracic surgery
•Many methods can be used for OLV. Optimal
methods depends on indication, patient
factors, equipment, skills and level of training
•FOB is the key equipment for OLV
•Principle physiologic change of OLV is the
redistribution of pulmonary blood flow to
keep an appropriate V/Q match
•Management of OLV is a challenge for the
anesthesiologist, requiring knowledge, skill,
vigilance, experience, and practice

one lung ventillation, problem based learning

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Editor's Notes