Key Terms Flashcards
What is the dose of lidocaine (bolus and infusion) for a reactive airway?
Bolus: 1-2 mg/kg Infusion: 1-4 mg/min
How do you confirm placement of an LMA?
Inflate the cuff and observe connector rise Listen for leak at 20 cm H2O Observe bag movement Capnography **Follow the same standards as ETT
What is the primary cause of hypoxemia for pts with emphysema?
V/Q mismatch. AKA dead space
Note: This results from the irreversible destruction of the alveolar septa.
What is a normal range for fibrinogen?
200 - 400 mg/dL
What will cause a decrease in end-tidal PCO2 for a pt that is neuromuscularly blocked and mechanically ventilated?
Hyperventilation
What does base excess in hemoglobin represent?
The amount of acid or base that is required to return the blood pH to a normal under standard conditions. Base Excess is the METABOLIC component of acid-base balance. + value indicates metabolic alkalosis - value indicated metabolic acidosis
How is carbon dioxide transported in whole blood?
It is transported in 3 forms:
- dissolved in solution
- bicarbonate
- with proteins in the form of carbamino compounds
What is an acid-base disorder that results from excess LR?
Metabolic alkalosis
How much potassium is in LR?
4 mEq/L
What percent of colloid will remain in the intravascular space?
100%
What percent of crystalloid will remain in the intravascular space?
33.33%
How do you calculate dynamic lung compliance?
VT/(PIP-PEEP)
How much nitrogen is washed out after 1 time constant?
37%
What is the CaO2 equation?
(1.39 * Hb * SaO2) + (0.003 * PaO2)
SaO2 is obtained from the arterial blood gas and expressed as a percent value.
How do you travel with a chest tube in place?
Take the patient off the wall suction and put the patient on a water seal so that the air doesn’t go back into the chest.
What are the variables for cardiopulmonary shunt fraction?
Perfusion without ventilation, or, decreased V/Q ratio
How is cardiopulmonary oxygenating ability assessed?
Alveolar-arterial gradient
Note: A-a gradient is normally less than 15mmHg.
Normal A-a gradient= 4+ (age/4) or 5 mmHg +(5 per decade over 2nd decade)
How do you assess chronic bronchitis?
- Regarding Hct?
- Pulmonary pressures?
- Cor pulmonale?
- PaCO2?
- Erythrocytosis
- Pulmonary HTN
- RV failure (cor pulmonale)
- CO2 retention
Chronic bronchitis is the presence of a productive cough for 3 consecutive months for at least 2 consecutive years.
What are helpful preop studies/evaluations when evaluating pts with chronic bronchitis? (5)
- Dyspnea
- Sputum
- Wheezing
- FEV < 50% (PFTs)
- Chest x-rays
How do you perioperatively manage a pt with chronic bronchitis? (6)
- regional preferred
- frequent blood/gas assessments
- preoxygenate well
- use humidified gases
- avoid nitrous
- ventilate with small to moderate tidal volumes with slow rates to prevent air trapping
How much does PaCO2 rise during the 1st minute of apnea?
How much will it rise each minute after the 1st?
~ 6mmHg
~ 3-4 mmHg
What is the arterial - end tidal carbon dioxide difference in a normal patient?
< 5 mmHg
Because end-tidal gas is primarily alveolar gas, and PACO2 = PaCO2
What causes pneumothorax? (2)
puncture of parieta pleura or visceral pleura
air trapped distal to the block will be absorbed by the blood causing that segment of the lung will collapse
What are the signs of pneumothorax? (10)
- chest pain
- SOB
- increased peak inspiratory pressures
- tachycardia
- hypotension (decreased venous return)
- hypoxia (atelectasis)
- distended neck veins
- unequal breath sounds
- tracheal deviation
- mediastinal shift away from the pneumothorax
What is normal PaO2 (room air)?
100 mmHg
What is PaO2 (50% oxygen)?
330 mmHg
What is PaO2 (100% O2)?
663 mmHg
What is normal PaCO2?
~40 mmHg
What is the normal range for pH?
7.35-7.45
What is the normal range for HCO3?
22-26 mEq/L
What is normal PvO2?
40 mmHg
What is normal PvCO2?
45 mmHg
What does this capnogram indicate?

Rebreathing
What are the main causes for rebreathing? (2)
- failure of inspiratory or expiratory valves
- exhausted CO2 absorbent
How do you calculate FiO2 for a nasal cannula?
1 L/min increases FiO2 by 3% up to 5 L/min
- 1 L/min = 24%
- 2L/min = 27%
How does the valsalva maneuver affect intrathoracic pressure?
Increases intrathoracic pressure
What are 2 contraindications for a nasal airway?
- Basilar skull fracture
- Coagulopathy–on heparin
To confirm endotracheal intubation and bilateral breath sounds, where must you auscultate?
mid axillary line
If, following induction and intubation, chest rise and condensate are observed but no capnographic waveform appears on the monitor, what is the next most appropriate step?
Breathe into the sampling line
What LMA size is appropriate for a 1000 gram neonate?
LMA size 1
To minimize IV fluid requirements while maintaining as much infused IV solution as possible in the vascular compartment, what type of IVF should be administered?
Colloid, Hextend especially since it stays in IV space longest.
What chronic obstructive pulmonary disease involves intermittent chest tightness, wheezing, and SOB interspersed with long periods during which these symptoms are not present?
Asthma
Hyperlucency in a preop CXR would most likely be associated with which type of pulmonary disease?
Emphysema
Preop evaluation of a 67 y/o with 76 pack years of tobacco abuse reveals dyspnea while speaking, a barrel chest, and circumoral cyanosis. If the pt denies chronic cough and recent URI, what pulmonary disease does he most likely have?
Emphysema
What type of COPD is most associated with a barrel chest?
emphysema
What cardiovascular problem would be expected to occur following induction and intubation?
hypotension
What finding during spontaneous ventilation via the anesthesia circuit prior to induction would reinforce your assessment of the pt’s pulmonary status?
capnograph
What measurement represents the best means for assessing the adequacy of alveolar ventilation?
PaCO2
Air bronchograms in a CXR would most likely be associated with which type of pulmonary disease?
pneumonia
What would most likely occur with emphysema in CXR? (5)
- increased lung volumes
- hyperlucency
- increased AP diameter
- large retrosternal air space
- flattened hemidiaphragm
What causes the oxyhemoglobin desaturation that sometimes occurs when nitroglycerin is given IV?
Hypoxic pulmonary vasoconstriction,
aka R–> L SHUNT
During preop evaluation, a pt with a 70 pack year history has some SOB with heavy activity, having a productive cough each morning and noticing that her sputum is changing color. Physical exam revals circumoral numbness. Vital signs include PR 72/min, BP 138/78, and T 37.5ºC.
What study should be obtained next?
CBC with differential
Mean pressure is very useful intraoperatively because: (2)
- End organ perfusion
- Identifies hemorrhage
A 68 y/o man with 68 pack years tobacco abuse was seen in preop prior to elective cholecystectomy. He was dyspneic during conversation, had a barrel chest, but denied chronic cough or recent URI. He is the 2nd case. Induction included fentanyl, lido, prop, and roc.
What cardiovascular problems will most likely occur in this patient following induction?
Hypotension
A 68 y/o man with 68 pack years tobacco abuse was seen in preop prior to elective cholecystectomy. He was dyspneic during conversation, had a barrel chest, but denied chronic cough or recent URI. He is the 2nd case. Induction included fentanyl, lido, prop, and roc.
What cardiovascular problems will most likely occur in this patient following intubation?
Hypotension
A 68 y/o man with 68 pack years tobacco abuse was seen in preop prior to elective cholecystectomy. He was dyspneic during conversation, had a barrel chest, but denied chronic cough or recent URI. He is the 2nd case. Induction included fentanyl, lido, prop, and roc.
What cardiovascular problems will most likely occur in this patient during mechanical ventilation?
hypotension
What measurement is the best method for determining adequacy of alveolar ventilation?
PaCO2
What physiologic variables can shift a normal, adult oxyhemoglobin dissociation curve?
RIGHT
Causes a shift to the Right:
Increases
2,3 dpG
H+
Temp
What is the jaw thrust maneuver useful for? (4)
- Bag and mask
- FFOB assisted intubation
- Insertion of NG/OG
- Insertion of an oral airway
What can occur with high FIO2 during a 2 hour general anesthetic producing postop hypoxemia?
DIFFUSION ATELECTASIS
An otherwise heathy patient bites down and occludes her ETT during emergence. Following successful extubation after awakening, the patient desaturates, SpO2 is 78% on facemask oxygen upon arrival to PACU.
What happened?
Negative pressure pulmonary edema
What are the cardiovascular effects of emphysema? (2)
- Cor pulmonale (from increase PA pressures)
- Mild decrease in PaO2
What is the takeoff of the right and left mainstem bronchus?
Right: 30º
Left: 45º
How do you calculate chest wall compliance?
change in lung volume / change in transthoracic pressure (PIP-PEEP)
What measurement represents the best means for assessing the adequacy of alveolar ventilation?
PaCO2
What size LMA is used for a 6.5-20 kg pt?
2
What size LMA for a 20-30 kg patient?
2.5
What size LMA for a 30 - 70 kg patient?
3
What size LMA for a > 70 kg patient?
4
What is the distibution of CO2 in whole blood?
- Plasma 7%
- Bicarbonate 70%
- 23% Hb and plasma protein
What is the cardiopulmonary shunt fraction equation?
Qs / Qt
Qs = venous admixture
Qt = cardiac output
What is Qs and Qt?
What is Qs/Qt?
Qs is venous admixture.
Qt is cardiac output.
Qs\Qt = (CcO2 - CaO2)/(CcO2-CvO2)
CcO2 = oxygen content of ideal pulmonary end-capillary blood