5. THORACIC ANESTHESIA
• Anesthesia for thoracic surgery requires
careful preoperative evaluation to
identify patients liable to develop post
operative morbidity especially the need
for continued mechanical ventilation
• Pulmonary function tests and ABG may be
useful to identify at risk patients
6.
7. THORACIC ANESTHESIA
• Thoracic anesthesia presents a unique set of
physiologic problems:
1)Lateral decubitus position
2)The open pneumothorax
3)One lung ventilation
• These physiologic changes requires careful
attention of the anesthetist to avoid serious
complications
8. THORACIC ANESTHESIA
1.1. Lateral position:Lateral position:
• It provides optimal access for most thoracic
procedures
• Unfortunately this position alters the normal
ventilation /perfusion relationship
( V/Q ).These derangements are further
accentuated by :
*induction of anesthesia *muscle paralysis
*opening the chest *surgical retraction
*initiation of mechanical ventilation
9.
10. THORACIC ANESTHESIA
• Although perfusion continues to favor the
lower lung, ventilation favors the upper lung
This mismatch markedly increase the risk of
hypoxia
• Also induction of G.A decreases FRC and moves
the lower lung( perfused) to a less compliant
part of the compliance curve
• Moreover PPV favors the upper lung as it is
more compliant
11. THORACIC ANESTHESIA
• All these effects worsen V/Q mismatching and
predispose to hypoxia
2. The Open PneumothoraxThe Open Pneumothorax :
• The lungs are kept expanded by the negative
pleural pressure .When one side of the chest is
opened the –ve pleural pressure is lost and the
lung is collapsed
• Spontaneous ventilation with open
pneumothorax in the lateral position results in
paradoxical respiration & mediastinal shift
12.
13.
14. THORACIC ANESTHESIA
• These two effects can cause progressive hypoxia
and hypercapnia but fortunately these can be
overcomed by the use of PPV
3. OneOne Lung Ventilation:Lung Ventilation:
• Intentional collapse of the lung on the operative
side greatly facilitates most thoracic procedures
but complicates anesthetic management
• The collapsed lung continues to be perfused and no
longer ventilated
15. THORACIC ANESTHESIA
• So the patient develops RT_LT intrapulmonary
shunt hypoxia
• Mixing of oxygenated blood from the ventilated lung
and unoxygenated blood from the collapsed lung
widens alveolar to arterial gradient hypoxia
• But fortunately the blood flow to the nonventilated
lung is decreased by hypoxic pulmonary
vasoconstriction and surgical compression of the
upper lung
16.
17. THORACIC ANESTHESIA
• Techniques for one lung ventilation:
1. Use of double lumen EBT
2. Use of single lumen ET + bronchial blocker
3. Use of single lumen EBT
• Double lumen endobronchial tube is often
used
18. THORACIC ANESTHESIA
• Indications for one lung ventilation:
•PATIENT
RELATED:
-CONFINED INFECTION TO ONE LUNG
-CONFINED BLEEDING TO ONE LUNG
-SEPARATE LUNG VENTILATION:
*large cyst or bulla *BPF *tracheobron. disruption
•PROCEDURE
RELATED:
-LUG RESECTION:
*pneumonectomy *lobectomy *segmental resection
-THORACOSCOPY
-ANT. APPROACH TO THORACIC SPINE
-ESOPHAGEAL SURGERY -B.A. LAVAGE
19. THORACIC ANESTHESIA
• Double lumen endobronchial tubes:
The principal advantage of double lumen tubes are
relative ease of placement, the ability of
ventilating either one or both lungs, the ability to
suction either lung
Name Bronchus Carinal hook
CARLENS LEFT YES
ROBERT-SHAW LEFT -RIGHT NO
WHITE RIGHT YES
20. THORACIC ANESTHESIA
• Placement of double lumen tubes (DLT):
1. Laryngoscopy with a curved blade
2. The DLT is passed with the distal curvature ant.
3. After the tip enters the larynx, the tube is
rotated 90 degrees to the side to be intubated
4. The tube is advanced till resistance is felt, the
average length is about 29 cm at the teeth
5. The tube position is established using a preset
protocol and confirmed by flexible fiberoptic
bronchoscopy
21.
22.
23. THORACIC ANESTHESIA
• Protocol for LT side DLT placement:
1. Inflate the tracheal cuff (5-10 ml)
2. Check for bilateral breath sounds.Unilateral sounds
indicate that the tube is so far, the tracheal lumen is
endobronchial {withdraw the tube little up }
3. Inflate the bronchial cuff (1-2 ml)
4. Clamp the tracheal lumen
5. Check for LT. side breath sounds:
a)persistence RT side .... Advance the tube
b)unilateral RT.... Incorrect entry into RT bronchus
6. Unclamp tracheal &clamp bronchial....diminished breath
sound on the RT {advance the tube }
24.
25. THORACIC ANESTHESIA
• After clamping of tracheal lumen, TV is usually set
to 10ml/kg and the RR is increased by20% to
maintain MV and PCO2
• Complications of DLT :
1. Hypoxia due tube malplacement or occlusion
2. Traumatic laryngitis
3. Tracheobronchial rupture due to overinflation of
the bronchial cuff
26.
27.
28. THORACIC ANESTHESIA
• The majority of patients undergoing
thoracic surgery have underlying lung
disease
• Specific preoperative findings that make
postoperative pulmonary complications
likely include: dyspnea, cough ,sputum
production, wheezing ,cigarette smoking,
obesity, recent RTI and advanced age
• The principle goal of preoperative
evaluation is to identify patients at risk
and to institute good preoperative therapy
29. THORACIC ANESTHESIA
• Preoperative prophylactic measures
Measures Result
Cessation of smoking HbCO2 decreases in 12-24h
so more O2 is available
Treat pulmonary infections Select antibiotics according
to culture and sensitivity
Treat bronchospasm Beta-2 agonists
Thin and mobilize secretions Hydration and chest
percussion
30. THORACIC ANESTHESIA
• Pulmonary function tests:
• Pulmonary function tests are helpful in
identifying patients at risk of developing
pulmonary complications
• In addition to PFT, ABG may be measured
in patients with sever dyspnea and
exercise intolerance
• The simplest and most informative test is
the FEV1, VC and analysis of the flow
volume curves
31. THORACIC ANESTHESIA
• The risk of postoperative pulmonary
complications is increased when:
1. FEV1 < 2 L
2. Ratio of FEV1/FVC < 0.5
3. VC < 15ml/kg
4. Presence of arterial hypoxemia &/or hypercarpia
• PFT & ABG should be repeated after
antibiotic and bronchodilator therapy to
confirm response to therapy
33. PREOPERATIVE MANAGMENTPREOPERATIVE MANAGMENT
1. Smoking increases the risk of COPD
and coronary artery disease. Echo is
very useful for assessing the
cardiac function
2. Patients with tumors should be
evaluated for local extension of the
tumor( tracheal or bronchial) and
paraneoplastic syndrome
3. Prophylactic digitalis especially in
resection of pulmonary tissues
34. PREMEDICATIONPREMEDICATION
• Patients with moderate to sever
respiratory compromise should
receive little or no premedication
• Anticholinergics are very useful in
reducing secretions and improve
visualization during attempts of
repeated Laryngoscopy and fiberoptic
bronchoscopy
35.
36. THORACIC ANESTHESIA
1)1) Preparation:Preparation:
• The frequent presence of poor pulmonary
reserve ,anatomic abnormalities or
compromise of the airway ,and the need for
one lung ventilation predispose these
patients to rapid hypoxemia
• A clear plan to deal with these difficults is
necessary
• Multiple single and double tubes should be
available, fiberoptic bronchoscope should
be available
37. THORACIC ANESTHESIA
• When epidural catheter is considered to be
placed it should be placed before induction
of anesthesia to offer patient cooperation
and decrease the incidence of neurological
complications
2) Venous access:2) Venous access:
• At least 2 large iv canula( 14-16 g) is
mandatory
• CV catheter, blood warmer ,rapid infusion
device are desired if blood loss is
anticipated
38. THORACIC ANESTHESIA
3) Monitoring:3) Monitoring:
• Beside routine monitors (ECG,ETCO2,SPO2,
NIBP) direct arterial monitoring is indicated
in patients with poor cardiac or respiratory
reserve and in resection of large tumors
• CVP monitoring is highly advisable and it
reflects the net effect of venous
capacitance ,blood volume, and RT ventricular
function
• PAC is indicated in LT ventricle dysfunction
39. THORACIC ANESTHESIA
4) Induction of anesthesia:4) Induction of anesthesia:
1. After adequate preoxygenation, iv
anesthesia is usually used for most patients
2. Direct Laryngoscopy is performed only
after deep anesthesia to prevent reflex
bronchospasm and obtund the
cardiovascular pressor response
3. Endotracheal intubation is facilitated by
succinylcholine or NDMR
40. THORACIC ANESTHESIA
4. Controlled PPV helps to prevent atelectasis,
mediastinal shift, paradoxical respiration
and facilitates surgery
5. Most thoracic procedures need DLT and its
position is confirmed after introduction and
after positioning using fiberoptic
bronchoscopy
41. THORACIC ANESTHESIA
5) Maintenance of anesthesia:5) Maintenance of anesthesia:
• All the current anesthetic techniques have
been used successfully for thoracic surgery
but the combination of a potent halogenated
agent + opioid is usually preferred
• N2O is not used
• Muscle paralysis is maintained with NDMR
• Iv fluids should be restricted to basic
requirement and blood loss to avoid Lower
Lung Syndrome especially in lung resection
42. THORACIC ANESTHESIA
• ONE LUNG VENTILATION:
The greatest risk of one lung ventilation is
hypoxemia. To reduce this risk ;
*the period of one lung ventilation kept
to minimum
*use 100% O2
Hypoxemia during one lung ventilation
requires one or more of the following
measures:
43. THORACIC ANESTHESIA
Sure effective
measures
Probably effective
measures
1. Periodic inflation of
the collapsed lung
2. 5-10cm H2O CPAP to
the collapsed lung
3. Early ligation of the
ipsilateral pulmonary
artery in
pneumonectomy
1. 5-10cm H2O PEEP to
the ventilated lung
2. Changing the TV and
the RR
3. Continuous
insufflation of O2 to
the collapsed lung
44. THORACIC ANESTHESIA
• If hypoxia persists :
• To immediate reexpansion of the collapsed
lung
• The position of the tube is verified
• The ETT is suctioned to exclude excessive
secretions or obstruction
• Pneumothorax on the dependant ventilated
side should be excluded
45. THORACIC ANESTHESIA
6) Postoperative management:6) Postoperative management:
• Most patients are extubated early to
reduce the risk of pulmonary barotrauma,
blowout of the bronchial stump and
pulmonary infection
• Double lumen tube is exchanged with
regular tube
• Patients are observed in PACU or ICU at
least overnight
46. THORACIC ANESTHESIA
• Pain management is of extreme
importance as pain delays extubation,
retains secretions and exaggerates
hypoxia
• Use either parentral (less preferred) or
epidural narcotics
• So routine postoperative care include:
-semisetting position -supplemental O2
-close hemodynamic monitoring
-aggressive pain management
48. THORACIC ANESTHESIA
1.1. Pulmonary cysts and bullae:Pulmonary cysts and bullae:
• The greater risk of anesthesia is rupture
during PPV tension pneumothorax
• Induction of anesthesia with maintenance
of spontaneous ventilation is desirable till
the side of the bullae is opened
• N2O is omitted because it can enlarge the
air cavity
• Pneumothorax is signaled by sudden onset
of hypotension, bronchospasm, peak
pressure
49. THORACIC ANESTHESIA
2. Lung abscess:2. Lung abscess:
• Anesthetic management depends on early
separation of both lungs to prevent soiling
of the healthy lung
• Rapid sequence iv induction with DLT with
the patient in semi-up right position with
the affected lung dependant
• Frequent suctioning of the diseased to
prevent soiling of the healthy lung
50. THORACIC ANESTHESIA
3. Bronchpleural fistula :3. Bronchpleural fistula :
• Anesthetic management may be complicated
by inability to ventilate the lungs because of
large air leak
• Rapid sequence iv induction with DLT or
awake intubation with DLT to separate both
lungs and ventilate the healthy lung only till
the fistula is closed