Anesthesia for thoracic surgery 3 Flashcards
The use of video camera and surgical instruments inserted through ports in the thoracic wall; usually 3-5 ports are used
Video-assisted thorascopic surgery (VATS)
Indications for thoracoscopic procedures include
lung biopsy wedge resection biopsy of hilar & mediastinal masses esophageal & pleural biopsy pericardiectomy
Advantages of VATs over thoracotomy
smaller incision; no intraoperative rib spreading; less postoperative pain
less risk of postoperative hypoxemia
faster recovery & discharge from hospital
Thoracoscopic surgery can be performed under
local, regional, or general anesthesia with two-lung ventilation or OLV
Preoperative evaluation and planning
discuss pain management options with patient
- PCA (for chest tube pain) & NSAIDs are usual after thoracoscopy
- consult with surgeon about likelihood of proceeding to thoracotomy
- otherwise same as with thoracotomy
Intraoperative considerations for thoracoscopic procedures include
GA/OLV with DLT or bronchial blocker is common
infiltration with local anesthesia by surgeon prior to placement of ports
lateral decubitus position
routine monitors
minimum one large bore PIV
a-line usually placed
end of procedure- lung is suctioned & gently re-inflated- change DLT to standard ETT if patient cannot be extubated
chest tube placed prior to closing
Intraoperative complications for thoracoscopic procedures include
CO2 insufflated used to improve surgical visualization- gas embolism & hemodynamic compromise
tension pneumothorax (rare)
hemorrhage (rare)
perforation of diaphragm or other organs (rare)
complications related to positioning and DLT
A mediastinoscopy is a
procedure is usually performed with lymph node or tissue biopsy to either establish a diagnosis (carcinoma of the lung, thymoma, or lymphoma), or to determine resectabilty of an intrathoracic tumor
Mediastinoscopy is performed through
small transverse incision just above suprasternal notch
blunt dissection along pre-tracheal fascia permits biopsy of paratracheal lymph nodes to the level of the carina
Compression to the innominate artery during a mediastinoscopy can
cause poor flow to right carotid artery and the right arm resulting in poor cerebral perfusion
Central airway obstruction may occur during mediastinoscopy due to
compression of the trachea during induction or manipulation of the mediastinoscope near the trachea
The technique for mediastinoscopy is
GA with ETT
Monitors for mediastinoscopy include
monitor a-line/pulse ox on RIGHT arm- if absent waveform ask surgeon to reposition mediastinoscope
BP on left
Pathology of mediastinal tumors includes
neurogenic tumors thymomas lymphomas cysts vascular masses esophageal lesions
90% of lymph node masses in the middle mediastinum result from
metastatic spread of malignancies
Signs & symptoms associated with mediastinal masses typically include
most are asymptomatic and discovered incidentally on CXR
symptomatic masses are usually malignant and are larger with extensive involvement- airway obstruction, impaired cerebral circulation, distortion of anatomy
Mediastinal tumors are frequently associated with the following systemic syndromes:
myasthenia gravis cushing's syndrome hypercalcemia hypertension myasthenic syndrome
Other signs & symptoms of mediastinal tumors include
cough, dyspnea, stridor, jugular distention, exaggerated changes in BP associated with postural changes
Progressive mediastinal tumor growth may result in compression of the SVC which leads to
obstruction of venous drainage in the upper thorax
Clinical manifestations of SVC syndrome include
Caval obstruction
edema of the face, conjunctiva, neck & upper chest
edema of the mouth, larynx, and airway obstruction
cyanosis
decreased cardiac output
increased ICP
venous backflow into upper extremity IV lines
Describe how caval obstruction occurs.
venous distension in the neck, thorax, & upper extremities
Describe why cyanosis occurs with SVC syndrome
mucosal edema & direct compression can severely compromise airflow in trachea
Describe why cardiac output is impacted with SVC syndrome.
may be severely depressed due to impeded venous return from upper body or by direct mechanical compression on the heart from tumor
Relative contraindications to mediastinoscopy include
SVC syndrome previous mediastinoscoy obstruction & distortion of airway impaired cerebral circulation myasthenic syndrome
Absolute contraindications to mediastinoscopy include
inoperability
coagulopathy
thoracic aortic aneurysm
Preoperative consideration for mediastinoscopy includes assessing for evidence of
airway compromise: dyspnea, tachypnea, tracheal compression or deviation
____________ are essential to assess size & location of tumor & to evaluate tracheal distortion or compression
preoperative CXR & CT scan
If airway compression is present in patients presenting for mediastinoscopy, obtain
PFTs in upright & supine positions: flow-volume loops detect airway obstruction
Many patients presenting for mediastinoscopy will favor the _________ position
upright
Worsening of symptoms of mediastinal mass may be precipitated by
muscle relaxants, coughing, breath holding & position changes
Monitoring for mediastinoscopy includes
large bore PIV x 2- may need to place in LE’s if s/s of SVC syndrome
monitor right radial pulse: doppler, arterial pressure line, pulse ox on right hand
blood pressure cuff monitoring in left arm
peripheral nerve stimulator
Complications of mediastinoscopy include:
acute airway obstruction difficulties with intubation & ventilation venous air embolism mediastinal hemorrhage (most common complication)
Describe the complication of acute airway obstruction.
long-standing tumors may cause tracheal malasia leading to tracheal collapse
GA with reinforced ETT
Describe the complication of difficult intubation and ventilation
have different ETT sizes available
establish ability to ventilate BEFORE muscle relaxation
muscle relaxation intraop to prevent coughing or straining
Describe the complication of venous air embolism.
HOB often 30 degrees elevation
Describe the complication of mediastinal hemorrhage.
surgical bleeding more likely in patients with increased CVP
do not over hydrate patient, especially those with SVC syndrome
If airway obstruction or SVC obstruction occurs, place the patient in
lateral, reverse trendelenburg, prone or high-Fowlers position–> may cause mass to shift away from trachea or SVC and relieve the obstruction
Describe anesthesia for mediastinoscopy.
deep anesthesia to blunt autonomic reflexes
vagally mediated reflex bradycardia from compression of trachea or great vessels
When managing anesthesia for mediastinoscopy, monitor for
instrument pressure against innominate, right subclavian, or right carotid arteries- loss of distal pulse, postoperative neurologic deficits
It is important to observe postoperative respiratory status closely for mediastinoscopy because
injury to recurrent laryngeal nerve (3rd most common injury) may result in hoarseness, vocal cord paralysis
injury to phrenic nerve
Describe emergence for mediastinoscopy.
prior to extubation- full TOF, full return of airway reflexes, patients with SVC syndrome must be fully awake as they can easily obstruct
postoperative CXR on all patients to rule out pneumothorax
Major complications of mediastinoscopy include:
hemorrhage pneumothorax RLN injury phrenic nerve injury/left hemiparesis esophageal injury air embolism dysrhythmias
The ability to perform________ and a detailed knowledge of ______ are necessary to provide reliable lung isolation
fiberoptic bronchoscopy & a detailed knowledge of bronchial anatomy
The standard method of providing lung isolation in adults is use of
double-lumen endobronchial tubes
-bronchial blockers are a reasonable alternative for lung isolation in patients with abnormal upper or lower airways
Patients undergoing pulmonary resection should have a preoperative assessment of their
respiratory function in three areas: lung mechanical function, pulmonary parenchymal function & cardiopulmonary reserve
Interventions that have been shown to decrease the incidence of respiratory complications in high-risk patients undergoing thoracic surgery include
cessation of smoking, physiotherapy, & thoracic epidural anesthesia
Geriatric patients are at a high risk for _____ after large pulmonary resections
cardiac complications, particularly arrhythmias
The best predictor of post-thoracotomy outcome in the elderly includes
preoperative exercise capacity
The use of large tidal volumes during OLV, can contribute to
acute lung injury, particularly in patients at increased respiratory risk such as after pneumonectomies
With the use of intravenous anesthetic techniques or volatile anesthetics at less than or equal to 1 MAC doses,
hypoxemia during one-lung ventilation occurs infrequently
-the use of CPAP or PEEP as treatment for hypoxemia during OLV should be guided by the individual patient’s lung mechanics
