Anaesthetic management in one lung ventilation

1. PHYSIOLOGY AND MANAGEMENT OF ONE
LUNG ANESTHESIA
PRESENTOR : DR SUMANTH S
MODERATOR : DR SUMALATHA

2. One lung ventilation
• The techniques of lung isolation are used to selectively ventilate the
lung within one hemithorax while the nearly motionless lung is
operated on in the contralateral hemithorax.
• Collapse of the nondependent lung produces less trauma than
surgical retraction and offers better exposure of structures within the
hemithorax

3. One lung ventilation (OLV)
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 (alveolar proteinosis)
• Video-assisted thoracoscopic surgery

4. RELATIVE INDICATIONS
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
.

8. BLOOD FLOW -LDP, AWAKE, CLOSED
CHEST, SPONTANEOUS BREATHING
• When the right lung is
nondependent, it
should receive
approximately 45 % of
total blood flow as
opposed to the 55 %
of the total blood flow
that it receives in the
upright and supine
positions
• When the left lung is
nondependent, it
should receive
approximately 35 % of
total blood flow as
opposed to the 45 %
of the total blood flow
that it receives in the
upright and supine
position.
RIGHT LUNG LEFT LUNG

9. Ventilation-ldp,AWAKE, Closed chest,
SPONTANEOUSLY BREATHING
• Gravity also causes a vertical gradient in the pleural
pressure, ventilation is relatively increased in the
dependent compared with the non dependent lung.
• The dome of the lower diaphragm is pushed higher
into the chest thus contract more efficiently than the
dome of the upper diaphragm.

11. LDP, ANAESTHETISED, SPONTANEOUS VENTILATION , Closed
chest
•The induction of general anaesthesia does not cause
significant change in the distribution of blood flow.
•Induction of general anaesthesia causes a reduction in the
volumes of both lungs secondary to a reduction in FRC.
•The reduction in volume in the dependent lung is greater
than that in the non-dependent lung because,

12. 1. The cephalad displacement of the dependent diaphragm by the
abdominal contents is more pronounced.
2. The mediastinal structures pressing on the dependent lung or
3. poor positioning of the dependent side on the operating table
prevents the proper expansion of the lung.
• These factors will move lungs to a lower volume on the S-shaped
volume–pressure curve .
• The nondependent lung moves to a steeper position on the
compliance curve and receives most of the ventilation, whereas the
dependent lung is on the flat (noncompliant) part of the curve. This
results in a significant V/Q mismatch

14. LDP, ANAESTHEtized, PARALYSED,
ARTIFICIAL VENTILATION,Closed chest
• Here, the highly curved diaphragm of the lower lung is no longer actively
contracting.
• Mediastinum rests on the lower lung and physically impedes lower lung
expansion.
• The weight of the abdominal contents pushing cephalad, against the
diaphragm is greatest in the dependent lung.
• Suboptimal Patient positioning
All these lower lung expansion and disproportionately decreases FRC.

15. LDP, AWAKE, BREATHING
SPONTANEOUSLY, open chest
• With the non-dependent hemithorax open,
atmospheric pressure in that cavity exceeds the
negative pleural pressure in the dependent
hemithorax.
• This imbalance of pressure on the two sides of the
mediastinum causes a further downward
displacement of the mediastinum into the dependent
thorax.

16. Two complications can arise from the patient
breathing spontaneously with an open chest
1. MEDIASTINAL SHIFT
2. PARADOXICAL RESPIRATION
MEDIASTINAL SHIFT- More during inspiration
There is negative pressure in the intact
hemithorax, compared with the less negative
pressure of the open hemithorax, can cause the
mediastinum to move vertically downward and
push into the dependent hemithorax

17. • The tidal volume in the dependent lung is decreased
by an amount equal to the inspiratory displacement
caused by mediastinal movement.
• This phenomenon is called Mediastinal shift.
• The mediastinal shift can create circulatory and reflex
changes that may result in a clinical picture similar to
that of shock and tension pneumothorax.

19. PARADOXICAL RESPIRATION-
• During inspiration, the relatively negative pressure in the intact hemi-
thorax compared with atmospheric pressure in the open hemi-thorax
can cause movement of air from the nondependent lung into the
dependent lung. The opposite occurs during expiration.
• This reversal of lung movement with an open chest during respiration
has been termed Paradoxical respiration.

20. • This gas movement reversal from one lung to the other represents
wasted ventilation and can compromise the adequacy of gas
exchange.
• Paradoxical breathing is increased by a large thoracotomy or by an
increase in airway resistance in the dependent lung.
• PREVENTION- controlled positive pressure ventilation OR adequate
sealing

22. LDP, ANAESTHETIZED, SPONTANEOUSly
BREATHINg, open chest
• Opening the chest has little impact on the distribution
of perfusion.
• However, the upper lung is now no longer restricted
by the chest wall and is free to expand.
• This results in a further increase in V/Q mismatch as
the nondependent lung is preferentially ventilated,
owing to a now increased compliance.

23. LDP, ANAESTHETIZED, MUSCLE PARALYSIS,
CHEST OPEN
• During paralysis and positive-pressure ventilation,
diaphragmatic displacement is maximal over the
nondependent lung.
• Here, there is the least amount of resistance to
diaphragmatic movement caused by the abdominal
contents.
• This further compromises the ventilation to the
dependent lung and increases the V /Q mismatch.

24. OLV, ANAESTHETIZED, PARALYSED, CHEST OPEN
• The essential difference between two lung and one
lung ventilation is that during one lung ventilation the
non-ventilated lung has some blood flow.
• Therefore, an obligatory shunt which is not present
during two lung ventilation is created .

25. BLOOD FLOW IN TLV Vs OLV
• During two-lung ventilation [TLV] in the lateral
position, the mean blood flow to the nondependent
lung is assumed to be 40% of cardiac output, whereas
60% of cardiac output goes to the dependent lung.
• Normally, venous admixture (shunt) in the lateral
position is 10% of cardiac output and is equally
divided as 5% in each lung.
• Therefore, the average percentage of cardiac output
participating in gas exchange is 35% in the
nondependent lung and 55% in the dependent lung.

26. • OLV creates an obligatory right-to-left transpulmonary
obsolute shunt through the nonventilated,
nondependent lung because the V/Q ratio of that
lung is zero.
• In theory, an additional 35% should be added to the
total shunt during OLV.
• However, assuming active HPV, blood flow to the
nondependent hypoxic lung will be decreased by 50%
and therefore it is (35/2) = 17.5%.

27. • To this, 5% must be added, which is the obligatory
shunt through the nondependent lung. Therefore the
total shunt in NDL is 22.5%
• Together with the 5% shunt in the dependent lung,
total shunt during OLV is 22.5% in NDL + 5% in DL =
27.5%. This results in a Acceptable PaO2 of
approximately 150 mm Hg (FiO2 = 1).
• Because 72.5% of the perfusion is directed to the
dependent lung during OLV, the matching of
ventilation in this lung is important for adequate gas
exchange.

29. Ventilation in olv
• The dependent lung is no longer on the steep
(compliant) portion of the volume–pressure curve
because of reduced lung volume and FRC.
• The causes for this reduction in FRC are:
1. General anaesthesia
2. Paralysis
3. pressure from abdominal contents
4. compression by the weight of mediastinal
structures
5. suboptimal positioning on the operating table.

30. • Other considerations that impair optimal ventilation
to the dependent lung include
1. absorption atelectasis,
2. accumulation of secretions, and
3. the formation of a transudate in the dependent
lung.
• All these create a low V/Q ratio and a large P(A–a)O2
gradient.

31. ROLE OF HPV IN OLV
• HPV is a reflex contraction of vascular smooth muscle
in pulmonary circulation in response to low regional
partial pressure of oxygen(PAo2>>.mixed venous Po2).
• Thus diverts blood area atelectatic/hypoxic alveoli
to better ventilated alveoli minizing shunt. Response
is greatest in distal pulmonary arteries.

32. Biphasic nature of HPV
• Phase 1 begins within a few seconds and is complete at 15 min. With moderate
hypoxia (Po2 30 to50mmHg),sustained for more than 30 to 60 min, phase 2 of
HPV begins- with further increase in pulmonary vascular resistance(PVR) is
seen,reachinfg peak at 2hrs.
• It can also be seen from figure that when normoxia returns after a sustained
period of hypoxia, PVR does not immediately return to baseline, indicating a
mechanism that takes hours to reverse.
• Greater hypoxemia when alternatively two lung are to be operated in same
time.

33. Factors affecting HPV
• low Alveolar paO2 >
mixed venous saturation
• Atelectasis
• at FRC- lowest PVR
• Low CO
• Anaemia
• Almitrine
• Patients with prior
respiratory disease have
greater HPV
• very high or very low pulmonary artery
pressures
• high or very low mixed venous PO2
• HighC.O,Hypocapnia,Hypothermia
• vasodilators such as nitroglycerin,
nitroprusside, PDI (milrinone , amrinone
AND sildenafil), β-adrenergic agonists,
CCB, Inhaled NO
• Acetazolamide-PASMCs,
• Steriods ,Endothelin antagonists –
Bosentan, sitaxsentan)
• AC enzyme inhibitors or AT II receptor
blockers
• activation of epidural
• inhalation anaesthetics(ether ,N2O
halothane).higher MAC (of other inhaled
anaesthetics)
Augmenting Inhibiting

34. OTHER MODIFIERS OF HPV
• Surgical retraction can assist HPV by increasing PVR in the operative
lung,
• However, the release of vasoactive substances secondary to the
manipulation may conversely result in an inhibition of HPV .
• Ligation of pulmonary vessels during lung resection results in the
permanent exclusion of vascular territory and thereby a reduction in
shunt flow .
• The side of surgery influences the extent of shunt flow, as the larger
right lung receives a 10% higher proportion of CO than the left lung.

35. • Positioning is important as the lateral decubitus position allows for a gravity
induced reduction in shunt flow to the nondependent lung.
• Procedures that call for supine positioning, on the other hand, are hampered
by higher shunt flow to the nondependent lung and may have higher rates of
intraoperative desaturations.
• Similarly, addition of a head-down tilt to the left lateral position has been
shown to worsen oxygenation during OLV, likely due to dependent lung
compression by abdominal contents.

36. Techniques for One-Lung Ventilation
Three techniques can be employed:
(1) Placement of a double-lumen bronchial tube;
(2) Use of a single-lumen tracheal tube in conjunction with a bronchial
 Blocker; Arndt (wire-guided) endobronchial blocker set
 Balloon-tipped luminal catheters
(3) Single-lumen ET with a built-in bronchial blocker, Univent Tube
(4) Insertion of a conventional endotracheal tube into a mainstem
bronchus
Double lumen tubes are most often used.

37. DOUBLE-LUMEN BRONCHIAL TUBES
• The principal advantages of double-lumen tubes are relative ease of placement,
the ability to ventilate one or both lungs, and the ability to suction either lung.
All double-lumen tubes share the following characteristics:
• A longer bronchial lumen that enters either the right or left main bronchus
and another shorter tracheal lumen that terminates in the lower trachea
• A preformed curve that when properly “aimed” allows preferential entry into a
bronchus
• A bronchial cuff
• A tracheal cuff

39. DOUBLE-LUMEN BRONCHIAL TUBES
• Ventilation can be delivered to only one lung by clamping the tube delivering gas
to either the bronchial or tracheal lumen with both cuffs inflated; disconnecting
the appropriate connection distal to the clamp site allows the ipsilateral lung to
collapse.
• Because of differences in bronchial anatomy between the two sides, tubes are
designed specifically for either the right or left bronchus.

40. DOUBLE-LUMEN BRONCHIAL TUBES
• A right-sided double-lumen tube incorporates a modified cuff and a proximal
portal on the endobronchial side for ventilation of the right upper lobe.
• As the left main bronchus is considerably longer than the right bronchus, there is a
narrow margin of safety on the right main bronchus, with potentially a greater risk
of upper lobe obstruction whenever a right-sided DLT is used.
• A left-sided DLT is preferred for both right- and left-sided procedures.
• The most commonly used double-lumen tubes are available in several sizes: 35,
37, 39, and 41 FR.

41. DOUBLE-LUMEN BRONCHIAL TUBES
• There are specific clinical situations in which the use of a right-sided
DLT is indicated
1. Distorted anatomy of the entrance of left mainstem bronchus by
external or intraluminar tumor compression or descending thoracic
aortic aneurysm
2. Site of surgery involving the left mainstem bronchus such as
• Left lung transplantation
• Left sided tracheobronchial disruption
• Left sided pneumonectomy
• Left sided sleeve resection

42. Types of Double lumen Tube
• Before the development of the Carlens left-sided DLT in 1950, a tube that was
designed for differential lung spirometry, anesthetists used either single lumen tubes
or bronchial blockers to produce lung isolation.
• Subsequently, the Robertshaw design DLT (which lacked a carinal hook) was
developed to facilitate thoracic surgery.
• This DLT is available in left-sided and right-sided forms.
• The absence of a carinal hook in Robertshaw design facilitates insertion

43. Types of Double lumen Tube

44. Types of Double lumen Tube
• This tube design has the advantages of having D-shaped, large-
diameter lumens that allow easy passage of a suction catheter, offer
low resistance to gas flow, and have a fixed curvature to facilitate
proper positioning and reduce the possibility of kinking.
• Red rubber tubes are rarely used now and have been replaced by
clear, polyvinyl chloride (PVC) disposable Robertshaw design DLTs.

45. Selection of DLT
• Patient’s height can be used as a basis for selecting a DLT.
• However, the correlation between airway size and height is extremely
poor.
• Tracheal and bronchial dimensions can be also directly measured from the
chest radiograph or chest CT scan.
• In patients in whom the left main bronchus cannot be directly measured,
the left bronchial diameter can be accurately estimated by measuring
tracheal width.

46. Selection of DLT
• The width of the left bronchus is directly proportional to tracheal width.
• The left bronchial width is estimated by multiplying the tracheal width by
0.68.
• The depth required for insertion of the DLT correlates with the height of
the patient.
• For any adult 170 to 180 cm tall, the average depth for a left sided
DLT is 29 cm.
• For every 10 cm increase or decrease in height, the DLT is advanced or
withdrawn 1 cm

47. Size of Double lumen Tube
• These are available in both right-sided and left-sided versions and in 35
French (Fr), 37 Fr, 39 Fr, and 41 Fr sizes.
• A 32-Fr left-sided DLT is available for small adults, and a 28 Fr for use in
pediatric cases.

48. Types of Double lumen Tube

49. Choice of double lumen tube

50. Placement of Double-lumen Tubes.
• Before placement of a double-lumen endotracheal tube, all necessary
equipment including a laryngoscope several double-lumen endotracheal
tubes, and a fiberoptic scope should be assembled and tested
• Direct laryngoscopy with a curved (Macintosh) laryngoscope blade is
preferred because the glottic opening is better exposed by it as compared
to a straight blade
• The double-lumen endotracheal tube is held with its bronchial curve
oriented anteriorly and its tracheal-pharyngeal curve oriented to the right.

51. Placement of Double-lumen Tubes
• The tube is advanced through the glottic opening until the bronchial
cuff just passes the vocal cords.
• After the tip of the tube is past the vocal cords, the stylet is removed, and
the tube is rotated through 90 degrees.
• A left-sided tube is rotated 90 degrees to the left, and a right-sided tube is
rotated to the right.

52. Blind method of inserting left sided DLT

53. Placement of Double-lumen Tubes
• Advancement of the tube ceases when moderate resistance to further passage is
encountered, indicating that the tube tip has been firmly seated in the main stem
bronchus
• A bifurcated connector is attached to the 2 lumens, and the tracheal cuff is inflated.
• Intubation of the trachea is then confirmed by capnography, auscultation, and
observation of chest excursion
• Once it has been determined that both lungs can be adequately ventilated, it is safe
to proceed with confirmation that the tube is positioned to allow isolation of the 2
lungs.

56. Placement of Double-lumen Tubes
• When problems are encountered in intubating the patient with the
double-lumen tube, placement of a single-lumen endotracheal tube
should be attempted.
• Once positioned in the trachea, the latter can be exchanged for the
double-lumen tube by using a specially designed catheter guide (“tube
exchanger”).

57. Protocol for checking placement of a left-sided
double-lumen tube.
1. Inflate the tracheal cuff ( 5-10ml) and confirm bilateral and equal breath sounds
2. Check for bilateral breathe sounds.
- Unilateral breath sound ?
3. Inflate bronchial cuff with 1-2ml of air ( rarely >2ml)
4. Clamp the tracheal lumen
5. Check for unilateral left-sided breath sound
- Persistence of right sided breath sounds???
- Unilateral right sided breath sound ???
- Absence of breath sound over the entire right lung and left upper lobe???

58. Protocol for checking placement of a left-sided
double-lumen tube
6. Unclamp the tracheal lumen and clamp the bronchial lumen
7. Check for unilateral right sided lumen
- Absence of diminution of breath sounds

59. USE OF A FIBEROPTIC BRONCHOSCOPE TO VERIFY PROPER PLACEMENT OF A
DOUBLE-LUMEN TUBE
Left-Sided Tube
• Tracheal lumen: Visualize the carina and upper surface of the blue
endobronchial cuff just below the carina
• Bronchial lumen: Identify the left upper lobe orifice
Right-Sided Tube
• Tracheal lumen: Visualize the carina
• Bronchial lumen: Identify the right upper lobe orifice

60. Properly positioned left double-lumen bronchial tube

61. Fiberoptic bronchoscopic view of the main carina (A), the “left
bronchial carina” (B), and the right bronchus(C)

62. Other methods for ensuring correct placement of a DLT
• Fluoroscopy,
• Chest radiography,
• Selective capnography, and use
• Underwater seal [If the tracheal lumen is connected to an
underwater seal system, gas will be seen to bubble up through the
water].

63. Complications of Double-Lumen Tubes
Major complications of double-lumen tubes include
• 1) Malpositioned DLT[ malpositioned DLT will fail to allow collapse of the lung, causing gas
trapping during positive-pressure ventilation, or it may partially collapse the ventilated or
dependent lung, producing hypoxemia
(2) Hypoxemia due to tube misplacement, tube occlusion, or excessive
degrees of venous admixture with one-lung ventilation;
(3) Traumatic laryngitis;
(4) Tracheobronchial rupture resulting from traumatic placement or over inflation of
the bronchial cuff; and
(5) Inadvertent suturing of the tube to a bronchus during surgery (detected as the
inability to withdraw the tube during attempted extubation

64. SINGLE-LUMEN TRACHEAL TUBES WITH A BRONCHIAL BLOCKER
• Bronchial blockers are inflatable devices that are passed alongside
(Univent TCB) or through a single-lumen tracheal tube(Arndt
Blocker) to selectively occlude a bronchial orifice.
• The bronchial blocker must be advanced, positioned, and inflated
under direct visualization via flexible bronchoscope.

65. SINGLE-LUMEN TRACHEAL TUBES WITH A BRONCHIAL BLOCKER
• The major advantage of a single-lumen tube with a bronchial blocker is
that, unlike a double-lumen tube, it does not need to be replaced with a
conventional tracheal tube if the patient will remain intubated
postoperatively
• Its major disadvantage is that the “blocked” lung collapses slowly (and
sometimes incompletely) because of the small size of the channel within
the blocker catheter.

66. Univent Tube

67. Arndt ENDOBRONCHIAL Blocker

68. Bronchial blockers with tracheal tubes
• There are specific conditions in which a bronchial blocker may be preferred
to a DLT, such as patients with previous oral or neck surgery who present
with a challenging airway and require lung separation for intrathoracic
surgery
• Another group of patients who may benefit from the use of bronchial
blockers are cancer patients who have undergone a previous contralateral
pulmonary resection

69. THREE LEGGED STOOL OF PRETHORACOTOMY
RESPIRATORY ASSESSMENT

70. • ppoFEV1%= Preoperative FEV1 x (1-%functional lung tissue removed/100)

71. Positioning
• Following induction, intubation, and confirmation of correct tracheal
or bronchial blocker position, additional venous access and
monitoring may be obtained before the patient is positioned for
surgery.
• Most lung resections are performed with the patient in the lateral
decubitus position.
• Proper positioning avoids injuries and facilitates surgical exposure
• Tube position to be reconfirmed after positioning of the patient

72. Positioning

73. VENTILATION PARAMETERS

74. Inspired Oxygen Fraction
• An FIO2 (fraction of inspired oxygen) of 1.0 is generally recommended
during OLV.
• High oxygen concentration serves to protect against hypoxemia during the
procedure and provides a higher margin of safety.
• A high FIO2 may, however, cause absorption atelectasis and potentially
further increase the amount of shunt because of the collapsed alveoli

75. Tidal Volume and Respiratory Rate.
 It has been recommended that during OLV, the dependent lung be ventilated
with a tidal volume of 10 to 12 mL/kg.
• A large VT of 12 mL/kg during OLV may cause over distention and stretching of
the lung parenchyma and therefore would increase the risk of ALI
 Recently, more attention has been directed toward protection of the ventilated
lung with the use of smaller VT of 5-6ml/kg to avoid acute lung injury (ALI)

76. Positive End-expiratory Pressure to the Dependent Lung.
• Combining low TV with a small amount of positive end expiratory
pressure (PEEP) (5 cm H2O) to protect from development of
atelectasis is the currently recommended ventilatory strategy
• PEEP Applied to Dependent lung causes increased pulmonary arterial
pressures and diversion of blood flow to non dependent lung that
increases shunting.

77. Continuous Positive Airway Pressure to the Nondependent Lung
 A lower level of continuous positive airway pressure (CPAP) (5–10 cm H2O)
maintains the patency of the nondependent lung alveoli, allowing some
oxygen uptake to occur in the distended alveoli.
 Most thoracic procedures are initiated thoracoscopically, and the
application of CPAP to the nondependent lung is generally not acceptable
to most surgeons

78. FLUID MANAGEMENT
• Following lung resection, there is an increased potential for
pulmonary edema to develop due to shunting of pulmonary
blood flow to remaining lung and raised pulmonary hydrostatic
pressure
• For the above reasons, it is important to avoid fluid over load in
the first hour intraopratively and 3L in the first 24 hours post
operatively.
• Intravenous fluids are administered to replace volume deficits
and for maintenance only during lung resection anesthesia
• No volume is given for “third space” losses
• Blood transfusion should be commenced at the usual clinical
triggers.
• If colloids have been administered, they may worsen the severity
of subsequent pulmonary edema as they cannot be resorbed as
quickly as crystalloid and hence should be avoided

79. HYPOXEMIA
PREDICTION OF HYPOXEMIA DURING OLV
• PREOPERATIVE VENTILATION-PERFUSION SCAN
The shunt and PaO2 during intraop olv corelate with fractional
perfusion of ventilated lung
• SIDE OF OPERATION
Right sided thoracotomies have a larger shunt and lower Pao2during
OLV because right lung is larger and normally 10% better perfused
• TWO LUNG OXYGENATION
Patients with better PaO2 levels during TLV in the lateral position tend
to have better oxygenation during OLV
• SUPINE POSITION FOR OLV

80. Hypoxemia during one lung ventilation
CAUSES
• Malplacement the tube
• Tube occlusion
• Excessive degrees of venous admixture

81. Management of Hypoxia
1. Adequate position of the bronchial tube (or bronchial blocker) must be
confirmed
2. Increase FiO2 to 1.0.
3. Recruitment maneuvers on the dependent, ventilated lung may eliminate
atelectasis and improve shunt.
4. Ensure that there is sufficient (but not excessive) PEEP to the dependent,
nonoperative lung to eliminate atelectasis.
5. CPAP or blow-by oxygen to the operative lung will decrease shunting and
improve oxygenation

82. 6. Two-lung ventilation should be instituted for severe hypoxemia. If possible,
pulmonary artery clamp can also be placed during pneumonectomy to eliminate
shunt.
7.In patients with chronic obstructive lung disease, one should always
be suspicious of pneumothorax on the dependent, ventilated side as
a cause of severe hypoxemia.
8. If other causes and maneuvers have failed to improve oxygen saturation and
one-lung anesthesia is required to complete the anesthetic, one can discontinue
all medications known to inhibit HPV (inhalation anesthetics, vasodilators, β-
agonists, etc) in favor of alternative drugs and techniques (eg, total intravenous
anesthesia, labetalol, etc).

83. POST OPERATIVE COMPLICATIONS
Atelectasis
The most common pulmonary complication following thoracotomy is
atelectasis.
• Significant atelectasis will cause a mismatch of ventilation with perfusion
and result in hypoxemia
• Atelectasis may develop from pulmonary injury during surgery,
incomplete lung re-expansion following one-lung ventilation, or from
bronchial obstruction by mucus as a result of inadequate clearance of
secretions

84. • Deep breathing, coughing, pulmonary toilet with suctioning, and
clearance of secretions with incentive spirometry, aerosolized
bronchodilators, and early postoperative ambulation are important.
• Effective pain relief is essential

85. Airway trauma
Injury to the airway can occur at any time during surgery and may go
unrecognized intraoperatively.
• A damaged airway can present postoperatively with respiratory distress, an air
leak, subcutaneous emphysema, hemorrhage, or cardiovascular instability
owing to tension pneumothorax.
• Immediate surgical intervention is essential.
• Any positive pressure ventilation, even mask-assisted ventilation, will cause gas
to enter either subcutaneous tissue or the chest, further exacerbating the
situation.
• An awake bronchoscope-guided intubation of the airway is recommended,
followed by spontaneous ventilation with an inhalational anesthetic agent.

86. Pneumothorax
In the presence of a bronchopleural communication, the volume of air in the
pleural space will increase.
• A tension pneumothorax will develop if air continues to enter the chest and is
not effectively decompressed.
• The risk of pneumothorax following pulmonary resection is reduced by
placement of a pleural drainage tube
• Immediate decompression with a large intravenous catheter or new chest tube
may be lifesaving

87. Cardiac herniation
• Cardiac herniation can occur after pneumonectomy if the adjacent
pericardium has been disrupted.
• If the pericardial defect is repaired intraoperatively, the risk of herniation
is low.
• Herniation is more common following right pneumonectomy.
• After left pneumonectomy, the great vessels and mediastinal structures
provide more of a barrier to herniation.

88. • The signs of cardiac herniation occur following surgery and may
include radiographic abnormalities, atrial and ventricular dysrhythmias,
sudden hypotension, and superior vena caval syndrome.
• Cardiovascular collapse occurs as a result of acute angulation of the
heart and great vessels.
• Hemodynamic stability can only return following surgical replacement of the heart
to its normal position

89. Hemorrhage
• The clinical signs of major hemorrhage (tachycardia, hypotension,
oliguria) are usually obvious in hypovolemic patients.
• Excessive chest tube drainage and a falling hematocrit are indications for
surgical reexploration.

90. Dysrhythmias
• Supraventricular dysrhythmias (atrial tachycardia, atrial flutter, and
atrial fibrillation) occur in as many as 20% of patients following
pneumonectomy.
• Arrhythmias can occur after any thoracotomy or video-assisted
thoracoscopic procedure.
• Advanced age and pre-existing cardiac disease are important risk factors
• Arrhythmias associated with profound hypotension require immediate
cardioversion.
• Verapamil and beta blockers can be used to treat these arrhythmias

91. Postpneumonectomy pulmonary edema
Pulmonary edema after pneumonectomy, an often fatal complication, is relatively
common.
• Postpneumonectomy pulmonary edema occurs in as many as 5% of patients.
• Some studies have associated positive fluid balance, while others find no clear-
cut relation between intraoperative fluid load and the development of pulmonary
edema.
• Postpneumonectomy pulmonary edema may be the result of increased
pulmonary endothelial permeability after pneumonectomy or impaired lymphatic
drainage

92. Right-heart failure
• Extensive lung resection decreases pulmonary vascular cross-sectional area,
resulting in increased pulmonary vascular resistance, which may lead to
acute right-heart failure with or without pulmonary edema.
• Postoperative hypoxemia can precipitate right-heart failure.
• Clinical signs of right-heart failure include supraventricular dysrhythmias,
distended neck veins, hepatomegaly, and peripheral edema.
• The electrocardiogram may demonstrate left and right ventricular strain, and
a chest radiograph may reveal right atrial and ventricular enlargement
• The therapeutic goal is to support right ventricular preload and decrease
pulmonary vascular resistance without lowering systemic blood pressure.
• Ventilatory support may be needed to correct reversible causes of increased
pulmonary vascular resistance (hypoxemia, hypercarbia, and respiratory
acidosis]

93. THANK YOU