Final Flashcards
Larynx vertebral location at birth vs adult?
C3-C4
C3-C6
Sphenopalatine ganglion innervation? What nerve?
nasal mucosa, superior pharnx, uvula, tonsils
CN V
Glossopharyngeal nerve innervation? What nerve?
oral pharynx, supraglottic region
CN IX
Internal branch Superior Laryngeal nerve innervation? What nerve?
mucus membrane above the VC’s, glottis
CN X
Recurrent Laryngeal nerve innervation?
trachea below VC’s
CN X
What does SLN divide into and what innervation?
Internal SLN - sensation to supraglottic & ventricle compartment, STIMULATION CAUSES LARYNGOSPASM
External SLN - motor innervation of cricothyroid muscle
____ RLN passes @ Aortic Arch
Provides ______ innervation to _______.
________ innervation to all larynx except _______ muscle
Left
Sensory
infraglottis
Motor
cricothyroid
Stimulation of what causes abduction of VC
RLN
Damage to RLN cause VC ______.
adduction
infant vs adult airway size? smallest part child vs adult?
4mm vs 8mm
cricoid cartilage vs vocal cords
Carina vertebral level and Cm from teeth?
T5-T7
25cm
What part of airway have thick O-ring?
Bronchioles
What nerve and Vertebral locations send innervation to diaphragm?
Phrenic nerve
C3, C4, C5
What nerve and Vertebral locations send innervation to external intercostal muscles?
Intercostal nerves (T 1-11)
The act of inhaling is?
negative-pressure ventilation
learn Vital capacity/lung volumes chart
.
Spirometry _________ measure Residual Volume (RV) thus Functional Residual Capacity (FRC) and Total Lung Capacity (TLC) cannot be determined using spirometry alone
cannot
FRC and TLC can be determined by?
1) Helium dilution
2) Nitrogen washout
3) body plethysmography
look at slide 20
.
surfactant functions?
- Lowers surface tension of alveoli & lung
- Increases compliance of lung
- Reduces work of breathing
- Promotes stability of alveoli
- Prevents transudation of fluid into alveoli
- Reduces surface hydrostatic pressure effects
- Prevents surface tension forces from drawing fluid into alveoli from capillary
Poiseuille’s Law
reducing r by 16% will double the R
reducing r by 50% will increase R 16-fold
two mechanisms for decreased pulmonary vascular resistance as vascular pressures rise
recruitment and distention
Functional capillary volume
70 ml (1 ml/kg body weight) normal volume at rest 200 ml at maximal anatomical volume
_____% of alveolar surface area covered by capillary bed
70-80%
look at slide 27-28
.
Vasoconstrictors?
Serotonin Thromboxane A2 Reduced PAO2 Angiotensin Prostaglandins Increased PCO2 Neuropeptides Norepinephrine Histamine α-adrenergic catecholamines Leukotrienes Endothelin
Vasodilators?
Nitric oxide Increased PAO2 Isoproterenol Prostacyclin Dopamine Acetylcholine β-adrenergic catecholamines Bradykinin
Alveolar hypoxia produces? Which is a _____________ of pulmonary arterioles caused by _____ and enhanced by _____ & _______. Is this the same or Opposite reaction of systemic circulation to hypoxia?
hypoxic pulmonary vasoconstriction (HPV)
Localized response
hypoxia
hypercapnia & acidosis
opposite
HPV is an important mechanism because? Results from decreased formation & release of ______ by pulmonary endothelium in hypoxic region.
Shift of flow to better ventilated pulmonary regions
Nitric Oxide
What causes biggest increase in pulmonary drive?
Hypoxia, hypercarbia
normal alveolar PO2?
100 mmHg
Normal alveolar PCO2?
40 mmHg
Alveolar air is expired at _____ of exhalation. What is expired first?
end
dead space
Ficks law consists of?
diffusion of gas through a tissue membrane consists of: -cross sectional area -gas coefficient -tissue thickness
pulmonary artery (deoxygenated blood) PCO2 and PO2 values?
46
40
pulmonary vein (oxygenated blood) PCO2 and PO2 values?
40
100
V/Q shunt occurs when? (2)
V/Q is below normal
Perfusion but no ventilation (no participation in gas exchange)
O2 sat and corresponding PaO2? 90 75 50?
60
40
27
PaO2 highest in?
Pulmonary capillaries
What causes a left shift in O2 curve?
Decreased Pco2
Decreased Temp
Decreased H+
Decreased 2,3 -DPG
What causes a Right shift in O2 curve?
increased Pco2
increased Temp
increased H+
increased 2,3 -DPG
Right shift O2 curve will have?
Hb has less affinity for O2, releases O2, saturation will be less for a given PO2
Left shift O2 curve will have?
Hb has higher affinity for O2, binds O2, saturation will be higher for a given PO2
O2 Content in blood (CaO2) equals? what equation?
The sum of O2 carried on Hb and dissolved in plasma
CaO2 = (SO2 * [Hb] * 1.31) + (PO2 * 0.003)
Co2 transported as what in blood? (3) mostly by what?
Co2
Hgb + Co2
HCO3 (mostly this way)
What controls Inspiration and respiratory rhythm? Where does it receive signals from?
Dorsal respiratory group (DRG)
- Peripheral chemoreceptors
- Baroreceptors
- Lung receptors
CO2 is _____ permeable to blood-brain barrier so blood & brain concentrations are equal. The released _________ in brain stimulate respiratory center activity.
highly
H+ ions
Drastic _______ in ventilation caused by _______ in Pco2 (above ___ mmHg)
increase
increase
35
Change in respiration is 10 times _____ with blood pH range between 7.3 and 7.5
less
peripheral chemo receptors located?
Carotids (CN IX) and aorta (CN X)
stimulation of chemoreceptors is by?
decreased arterial oxygen content
Intubation criteria: Mechanics
- RR>35
- VC <15cc/Kg in adult or <10cc/Kg in child
- MIF more neg. than -20cmH2O
Intubation criteria: Oxygenation
- PaO2 < 70mmHg on FiO2 of 40%
- A-a gradient > 350mmHg on 100% O2
Intubation criteria: Ventilation
- PaCO2 > 55 (except in chronic hypercarbia)
- Vd/Vt > 0.6 (remember normal dead space is 30%)
Intubation criteria: Clinical
airway burn chemical burn epiglottitis mental status change rapidly deteriorating pulmonary status fatigue
Extubation criteria:
- VSS, awake & alert, resp. rate < 30
- ABG on FiO2 of 40% PaO2 >70 and PaCO2 <55
- MIF is more negative than -20cm H2O
- Vital capacity (VC) > 15cc/Kg
Rule: an INCREASE of PCO2 by ___ mmHg causes a DECREASE in pH by ____ and vice versa.
10
0.08
A-a gradient is? equation to figure out? Tx if abnormal?
a measure of efficiency of lung
approximately (Age / 3)
- supplemental O2
- adjust ventilation
- tx atelectasis
- add PEEP
- tx underlying cause**
A DECREASE in bicarb. by ____ mmoles DECREASES the pH by _____.
10
0.15
Total body bicarb. deficit = ? usually replace __ of deficit
(base deficit * wt in Kg * 0.4)
½
940nm = _____ light, oxyhemoglobin.
infrared
Carboxyhemoglobin reads what on pulse ox?
100%
Methemoglobin reads what on pulse ox? absorbs _______ at both wavelengths
85%
equally
_____ hemoglobin and ______ do not affect pulse oximetry.
Fetal
bilirubin
In the _________ position the dependent lung is better perfused (gravity) & ventilated. With induction of anesthesia, with a decrease in FRC, the ______ lung _______ more, V/Q mismatch
awake & lateral
upper
ventilates
Factors that inhibit hypoxic pulmonary vasoconstriction:
- Very high or very low pulmonary artery pressures
- Hypocapnia
- High or very low mixed venous PO2
- Vasodilators: nitroglycerin (NTG), nitroprusside (SNP), b-adrenegic agonists (dobutamine), calcium channel blockers
- Pulmonary infections
- Inhalation agents
Hypoxia during one lung ventilation:
- FIO2 of 0.8 to 1.0
- Check tidal volumes – want 10cc/Kg, suction ETT
- Fiberoptic scope to ensure proper ETT placement
- Adjust RR to keep PaCO2 at 40mmHg
- Add 5cm H2O CPAP to nondependent lung – warn surgeon
- Add 5cm H2O PEEP to dependent lung – tx’s atelectasis but may increase vascular resistance
- Increase both CPAP and PEEP slowly
- Ask surgeon to clamp or ligate nondependent PA
- Return to two lung ventilation always an option
S/S MH:
- Tachycardia
- Increased ETCO2 (2-3x)
- decrease in SaO2 & SpO2
- rigidity despite muscle relaxant onboard
- dysrhythmias
- tachypnea
- cyanosis
- sweating
- unstable BP
- mottling of skin
- trismus (masseter spasm) after succinylcholine
- darkening of blood in surgical field
- decreased mixed venous saturation
- cola-colored urine
- heating and exhaustion of CO2 absorber
- hyperthermia (up to 2 degrees C per hour)
What will labs be during MH?
- myoglobinuria
- initial metabolic acidosis then a combined metabolic & respiratory acidosis
- creatinine kinase (CK) > 1000 IU
- hyperkalemia
- hypercalcemia
- hyperphosphatemia
- hypoxemia
Factors that increase MAC:
- Age: term infant to 6 months of age has the highest MAC requirement**
- Hyperthermia
- Chronic EtOH abuse**
- Hypernatremia
- Drugs that increase CNS catecholamines
Factors that decrease MAC:
- Hypothermia: for every 1 deg. C drop in body temp – MAC decreases 2 to 5%
- Preop medications
- IV anesthetics, opioids
- Neonate/Premature infants
- Elderly
- Pregnancy**
- Acute EtOH ingestion
- Lithium
- Cardiopulmonary bypass (CPB)
- Hyponatremia
- Alpha 2 agonists
- Calcium channel blockers
- Severe hypoxemia – PaO2 < 38 mmHg
Factors that have no effect on MAC:
- Thyroid gland dysfunction**
- Duration of anesthesia
- Gender
- Hyperkalemia
- Hypokalemia
- Hypocarbia
- Hypercarbia
Preop smoking cessation
-Advise stopping at least 12 hours prior to surgery
Stopped night before surgery (12-24 hrs) – will reduce COHb and nicotine levels to that of nonsmokers
-Airway reactivity decreases after 2 days of cessation and is near the level of a nonsmoker after 10 days of cessation
-Cessation of > 8 weeks will reduce post-op pulmonary complications
-Cessation of > 2 years will reduces risk of MI to that of nonsmoking population
COPD Intraoperatively
-Bronchospasm: avoid *histamine releasing drugs
Pentothal (STP), Morphine (MSO4), Atracurium, Mivacurium, Neostigmine
-Tx with nebulized albuterol especially before extubation
V/Q in physiologic shunt vs physiologic deadspace?
which has perfusion/ventilation
Shunt: V/Q below normal - perfusion
Deadspace: V/Q above normal - ventilation