Anesthesia for thoracic surgery 2 Flashcards
Correct placement of a double lumen tube includes
no herniation of the cuff over the carina
Problems with DLT placement include:
in too far
not far enough
wrong side
The most common problem encountered when positioning a LEFT endobronchial tube is
inserting too deeply, excluding right lung from ventilation
The most common problem encountered when positioning a RIGHT endobronchial tube is
excluding the right upper lobe from ventilation
Left endobronchial tubes may be used for:
right-sided thoracotomy
left-sided thoracotomy
When using a left endobronchial tube for a right-sided thoracotomy, the ______ lumen
tracheal lumen is clamped and left lung ventilated through bronchial lumen
When using a left endobronchial tube for a left-sided thoracotomy, the ____ lumen is clamped
bronchial lumen is clamped and right lung is ventilated through tracheal lumen
When using a left endobronchial tube for a left-sided thoracotomy, if the surgeon needs to clamp the left mainstem for pneumonectomy,
move bronchial lumen into the trachea and then use as a standard ETT
Indications for using a right double lumen tube include
resection of a thoracic aortic aneurysm
tumor in left mainstem bronchus
left lung transplantation or left pneumonectomy (not absolute)
left-sided tracheo-bronchial disruption
A bronchial blocker is an
inflatable device passed alongside or through a single-lumen ETT to selectively occlude a bronchial orifice
A univent tube is a
single lumen ETT with built-in side channel for retractable bronchial blocker
A regular ETT can be used as a bronchial blocker when
an inflatable catheter is used and a guide wire is used for placement
A bronchial blocker must be advanced, positioned, and inflated under
direct visualization via flexible bronchoscope
A major advantage of a bronchial blocker is
patient who requires intubation postoperatively- do not have to redo their laryngoscopy and change out ETT
A major disadvantage of a bronchial blocker is
blocked lung collapses slowly & sometimes incompletely due to small size of channel within the blocker
Placing a univent bronchial blocker includes
ETT is placed with blocker fully retracted
ETT is then turned 90 degrees towards the operative side
bronchial blocker is pushed to the mainstem bronchus under direct visualization with fiberoptic scope
The cuff of the univent bronchial blocker is
high pressure-low volume cuff so use minimum volume to prevent leak
The channel within the univent bronchial blocker allows lungs
to slowly deflate
-channel can also be used for suctioning or insufflating oxygen
A fogarty catheter is
not used commonly anymore
used with standard ETT
guide wire in catheter is used to facilitate placement through ETT
does not allow suctioning or ventilation of the isolated lung
Indications for lung resection include
diagnosis & treatment of pulmonary tumors
necrotizing pulmonary infections
bronchiectasis
Preoperative preparation must consider:
does the risk of potential postop complications preclude performing the surgery?
will postop pulmonary function be sufficient to allow reasonable quality of life?
Preoperative testing includes:
CXR/ chest CT EKG ABG PFTs Ventilation-perfusion tests
Many patients undergoing a thoracic surgery will have
CAD combined with lung problems so consider appropriate cardiac diagnostics
Describe low risk & high risk PFTs.
FEV1 >2L or 80% predicted: low risk
FEV1 <2L or 40% predicted: high risk
A risk assessment for pneumonectomy takes into account:
arterial blood gas FEV1 FEV1/FVC maximum O2 uptake (VO2) maximum voluntary ventilation
Describe a high risk patient for a pneumonectomy based on arterial blood gas.
PaCO2> 45 mmHg (on room air)
PaO2 < 50 mmHg
Describe a high risk patient for a pneumonectomy based on FEV1.
<2L or <50% of predicted
Describe a high risk patient for pneumonectomy based on FEV1/FVC
<50% of predicted
Describe a high risk patient for pneumonectomy based on maximum O2 uptake (VO2).
<10 mL/kg/min
Describe a high risk patient for pneumonectomy based on maximum voluntary ventilation.
<50% of predicted
A split-lung function test uses
radio-labeled albumin to calculate the predicted pulmonary function, postoperative outcome, & survival after pneumonectomy
The minimal predicted postoperative FEV1 necessary for long-term survival is
800-1000 mL
A split-lung function test predicts FEV1 of
an isolated lung if the other lung is removed
-predicted postop FEV1= preop total FEV1 x % blood flow to remaining lung
Concerns with preoperative chemotherapy include
cardiomyopathy
pulmonary toxicity
bone marrow suppression
Chemotherapy induced cardiomyopathy may be the result of
doxorubicin
cyclophosphamide
-check preop echo
Chemotherapy induced pulmonary toxicity may be the result of
bleomycin (pulmonary toxicity with high FiO2)
mitomycin-C
cyclophosphamide
Chemotherapy induced bone marrow suppression is the result of
most chemotherapeutic agents
check platelets, RBCs, WBCs
Non-small cell lung carcinoma is the result of
ectopic parathyroid hormone
Small cell lung carcinoma may be the result of
SIADH
lambert-eaton myasthenic syndrome
carcinoid syndrome
SIADH oat cell carcinoma of the lung may cause
low urine output, hypervolemia, hyponatremia, CHF, & pulmonary edema
Lambert Eaton myasthenic syndrome is associated with
small cell lung CA
increased muscle weakness due to decreased calcium levels at neuromuscular junction
Management of one lung ventilation includes always
getting baseline ABG prior to instituting OLV; this is your reference point
With chest opening and rib splitting,
maximum depth of anethesia is necessary
It is important to maintain______ until pleura is opened
two-lung ventilation
During one-lung ventilation when the operative lung is deflated,
100% O2 to dependent lung
obtain ABG 15 minutes after OLV is initiated; guide therapy to maintain near baseline
major adjustments in ventilation usually not necessary
The greatest risk during one lung ventilation management is
hypoxemia!
If you experience high peak inspiratory pressures during one lung ventilation
check ETT position
reduce Vt & increase RR to maintain minute ventilation
Describe how to ventilate the dependent lung.
Fio2 100%; can decrease after ABG obtained
Vt 5-6 mL/kg- not necessary to change with OLV
PEEP 0-5 mmHg
RR 12-15 to keep PaCO2 35-45 mmHg (or close to preoperative value)
The recommended mode of ventilation for one lung ventilation is
volume or pressure control
-pressure control for patients at risk of lung injury (e.g. bullae, pneumonectomy, post lung transplantation)
The following steps should be taken if hypoxemia is experienced during OLV
confirm tube placement & increase fiO2 to 100%
check hemodynamic status
adjust TV &/or RR
add 2-10 cmH2O CPAP to collapsed lung
periodically inflate collapsed lung with 100% oxygen (inform surgeon)
add 5-10 cmH2O PEEP to dependent lung
continuous insufflation to collapsed lung with 100% O2
early ligation/clamping of the ipsilateral pulmonary artery (if doing pneumonectomy)
Alternatives to one lung ventilation includes:
stopping ventilation for short periods & employing use of 100% O2 insufflated at a rate greater than O2 consumption
HFJV- low volumes, high pressure
Apneic oxygenation is
useful for 10-20 minutes
can cause progressive respiratory acidosis: PaCO2 rises 6 mmHg first minute, 3-4 mmHg each subsequent minute
Emergence with one lung ventilation may include
inflate lung to 30 cmH2O pressure/may request valsava
thoracotomy tubes may be placed
standard extubation criteria for patients you anticipate extubating at end of procedure
If the patient is to remain intubated,
must change out to single-lumen ETT prior to transporting to unit
A valsava may be used to
check for leaks if stapling bronchus
check for microbleeding to re-inflate collapsed lung
Complications from thoracic anesthesia may include:
hypoxemia/respiratory acidosis (#1 complication) postoperative hemorrhage arrhythmias bronchial rupture acute right ventricular failure positioning injuries
Hypoxemia/respiratory acidosis may result from
atelectasis & shallow breathing (splinting) due to incisional pain
gravity dependent transudation of fluid into dependent lung
Postoperative hemorrhage signs include
chest tube drainage >200 mL/min.
hypotension, tachycardia, decreasing Hct
associated with 20% mortality
The most common arrhythmia from thoracic anesthesia is
atrial fibrillation
Acute right ventricular failure may present as
low CO, elevated CVP, oliguria
Bronchial rupture may be the result of
excessive cuff inflation of the bronchial tube
