CV Exam Flashcards
PPO FEV1 tell you
Airflow
If <40 = increased risk
VO2 max tell you what ?
Cardiopulmonary reserve
VO2max < 15 ml/kg/min = increased risk
>15ml/kg/min = average risk
What does DLCO max tell you
Parenchymal function
Small amount CO, hold breath 10 seconds, measured
Low sensitity good specificity
PPOP ( predictive post operative product )
5 flights of stairs = VO@ max
> 20 ml/kg/min
Favorable
What must be evaluated to anticipate the patient’’s intra operative and post op needs
Respiratory function
Post resection lung
Average risk patient , may be extubated immediately post op
VO2max >15 ml/kg/min
PPO FEV1 > 40 %
High risk patients will struggle to get off vent , what are the values
VO2max < 10
PPO FEV1 < 30 %
INtermediate risk patients , need to assess the patients on an individualized basis , what are the values
VO2 Max between 10 -15 ml/kg/min
PPO FEV1 30% -40 %
What are the principal advantages of double lumen tubes
Easy to place
Ability to ventilate one or both lungs
Ability to suction either lung
What are the disadvantages of double lumen tubes : ( 4)
- Size selection
- Difficult to place w/ difficult airways
- Not optimal for post op ventilation ( must be change out if pt to remain intubated )
All DLTs share what characteristics (4)
LONGER BRONCHIAL LUMEN that enters 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
Bronchial cuff
Tracheal cuff
Distance from right upper lobe to baring bifurcation is
1.5- 2 cm
Carina bifurcation to left mainsten is
4- 5 cm
Contraindication for left sided tube
Lesions of the airway
Compression of the trachea
Main bronchus by external mass
Right DLT can malposition more than left , so for that reason which DLT is used more ?
Left , even for right thoracotomy
MC complication with DLT is
Malpositioning
Larger size DLT is probably responsible for what ?
Responsible for the slightly increased incidence of hoarseness and vocal cord lesions ( following DLT vs Bronchial blocker )
Table
Inflate tracheal cuff
Verify bilateral breath sounds
Inflate endobronchial cuff
Clamp Y pice to endobronchial lumen and open at atmosphere
A bronchial Blocker just be
Advanced , positioned and inflated under visualization via flexible bronchoscope
Patient has a diff airway or tracheostomy chose DLT or Bronchial Blocker , already intubated , pediatric lung separation needed ,
?
BB.
Doe bronchial blockers allow suctioning ?
No
Which has a greater indidence of malposition?
BB
Also requires more time than DLT
When is pediatric lung separation needed ?
Infection absolute indication of one lung ventilation
During two lung ventilation blood flow to the dependent are averages how much ?
60%
What happens to blood flow when one lung is deflated and one lung ventilation is started ?
Any blood floe to the deflated lung becomes shunt flow, causing the PaO2 to decrease
A 40% shunt would be anticipated w/o Autoregulation. But the lung have a compensatory mechanism of increasing vascular resistance in hypoxic areas of the lungs , and this diverts some blood flow to areas of better ventilation and oxygenation .
What is HPV
A reflex intrapulmonary feedback mechanism in inhomogeneous lung that improves gas exchange and arterial oxygenation
Hypoxia causes pulmonary arteries to vasoconstrict opposite of what happens in the rest of the body ( vasodilation ) with hypoxia.
HPV can increase PVR to what %?
50 to 300 %
What meds inhibit HVP
NTG Nitroprusside Dobutamine Isopreterenol ( some B2 agonist ) CCB Volatiles Mac >1.5 Hypocapnia
Vasoconstrictive drugs preferentially constrict well oxygenated arteries = reestablishing shunt flow = opposing the HPV effects .
Phenylephrine
Epinephrine
Dopamine
Factors that reduce effective of HPV
- Alkalosis
- Hypocapnia
- Excessive Vt or PEEP
- Hemodiluation
- Hypervolemia
- Hypothermia
- Prostacyclin
- Shunt fraction <20% or >80%
- Vasodilators , Phosphodiesterase Inhibitor 10.calcium channel blocker
- Volatile anesthetic >1.5 MAC
PaO2 from highest to lowest post various lung surgery
Pneumonectomy>Lobectomy> Segmentectomy
Smoking is not only a major risk factor for chronic lung disease but also a strong predictor of preop complication . True or false ?
True
The neurological innervation to the heart originates from
the autonomic nervous system, as well as from sensory fibers