VATS article- surgical procedure section Flashcards
Advantages for VATS procedure compared to open thoracotomy (4)
- decreased blood loss
- decreased rate of infection
- decreased post-op pain
- quicker recovery
What are the 2 primary reasons for V/Q mismatch (think v broad)
- greater ventilation and less perfusion in non-dependent lung
- Greater perfusion and less ventilation in dependent lung
Perfusion favors the dependent or non-dependent lung generally
dependent d/t gravity
What factors contribute to decreased ventilation of the dependent lung (3)
- suboptimal positioning
- compression of the lungs by mediastinum and abdominal contents
- decreased lung volume associated with GA
Is there a greater or lesser need for OLV with VATS compared to open thoracotomy
greater
Principle physiologic change associated with OLV
redistribution of lung perfusion between ventilated and non-ventilated lung
Once the lungs are isolated and OLV has initiated all blood flow to the nondependent lung becomes?
shunt flow
Allows the redirection of blood flow to alveoli with higher oxygen tension, thereby reducing V/Q mismatch
Hypoxic pulmonary vasoconstriction
HPV has been shown to have the greatest benefit when what % of the lung is hypoxic
30-70%
Factors known to inhibit HPV (6)
- systemic vasodilators (nitroglycerin, dobutamine, calcium channel blockers, beta-agonists)
- inhalation anesthetics
- v high or v low pulm artery pressures
- hypocapnia
- high or v low mixed venous pO2
- pulm infection
Factors that decrease blood flow to ventilated lung and direct blood flow to non-ventilated lung (counteracts HPV)
- high mean airway pressures (PEEP, hyperventilation, PIP)
- low FiO2
- vasoconstrictor medications
- intrinsic PEEP from short expiratory times
Labs for VATS procedure
- CBC
- metabolic panel
- glucose
- renal fxn
- liver fxn
- coags
- blood type and cross match
4 high-risk CV conditions that require additional screening and pre-op treatment
- unstable coronary syndromes
- decompensated heart failure
- significant cardiac arrhythmias
- severe valvular disease
What is the most common pre-op test used to evaluate thoracic disease
CXR
PaCO2 associated with increased perioperative risk (for laparoscopic?)
> 45mmHg
FEV1 associated with increased perioperative risk
< 2L
FEV1/FVC associated with increased perioperative risk
< 50% of predicted
maximum breathing capacity associated with increased perioperative risk
< 50% of predicted
residual volume/TLC associated with increased perioperative risk
> 50%
carbon dioxide diffusion in the lungs associated with increased perioperative risk
<60% of predicted
5 interventions to optimize pulm fxn pre-op
- stop smoking
- bronchodilator therapy
- decrease the viscosity of secretions
- secretion mobilazation
- adjunct care (pharmacologic and psychologic)
Preoperative interventions for patients with lung cancer should be implemented with consideration of the 4 Ms, what are they?
- mass effects
- metabolic effects
- metastases
- medications
Contraindications for VATS (12)
- inability to tolerate OLV
- inability to tolerate lateral decubitus position
- hemodynamic instability
- tumor >6cm
- chest wall involvement
- mediastinal involvement
- coagulopathy
- T3 tumor
- N2 disease
- hilar structure involvement
- preop chemo or radiation
- expansive intrapleural adhesions
what size tumor is contraindicated for VATS
> 6cm
If pt had pre-op radiation or chemo can they have a VATS procedure
nope
2 most common VATS complication
- prolonged air leak
- bleeding
prolonged air leak is more likely to occur after what specific procedure
lung resections
the greater the amount of lung tissue resected the greater the likelihood of
prolonged air leak
small air leaks are often resolved when
reexpansion of the noninflated lung over the course of a few days
When is an air leak considered prolonged
lasting more than 7 days
treatment for prolonged air leak
chest tube
If bleeding cannot be controlled during VATS what is done?
conversion to open thoracotomy
The formula for determining insertion depth of DLT
patient height in cm/10 + 12cm
ideal position for the bronchial cuff of DLT
3-5mm beyond carina
suggested TV
5-6ml/kg with PAP < 35
suggested PEEP
5cm H20 except with COPD patients
suggested RR
12-16/min
vent mode for patients at risk for lung injuries like pneumonectomy or bullae
pressure control
In the event of desaturation what steps should be followed to improve PaO2
- 100% FiO2
- bag ventilation
- check tube position
- CPAP
- PEEP
- intermittent 2 lung ventilation
- ask the surgeon to clamp pulm artery to the nondependent lung
The site at greatest risk for injury r.t positioning
brachial plexus
What can be used to keep weight off the dependent arm
chest roll between axilla
How should the nondependent arm NOT be positioned
- suspended from arm board or ether screen
- not abducted
- not flexed > 90 degrees
- not extended posteriorly
How can excessive fluid administration have a negative impact on patients during VATS (2)
- increases shunting
- pulmonary edema of dependent lung
What intra-op pain management option does not affect shunt or oxygenation while also providing excellent analgesia
thoracic epidural with GA
What is post-op pain management crucial
- facilitates improved resp effort
- decreased potential post-op complications
What is the concern with relying solely on IV opioids for post-op pain management
respiratory depression
What is the current standard analgesic therapy for post-op VATS pain
thoracic epidural at the T6-T8 interspace
Ipsilateral shoulder pain is common following thoracotomy as a result of what
separating the anterior serratus and latissimus dorsi muscles
