Critical Care Flashcards
What can you treat acute hyperkalemia with? (5 treatments)
- Insulin
- Calcium
- Kayexalate (not acute effects though)
- NaHCO3
- Beta agonist - drives K+ into cells
What are 2 types of ventilators?
What are their features/uses and subtypes?
- Volume-cycled: can lead to high airway pressures. Not recommended for severe respiratory distress or decreased compliance.
Subtypes:
a) Intermittent mandatory ventilation
b) Assist control ventilation - Pressure-cycled: good for decreased lung compliance patients.
Subtypes:
a) Intermittent positive pressure ventilation -
b) Airway pressure release ventilation = BiVent – CPAP that releases at timed intervals
-minimizes peak airway pressure and lengthens inspiration.
-Works by mainly changing FRC.
-Can still use PEEP when needed.
Draw out the lung volume chart (in your head)!
What makes up the inspiratory capacity? The vital capacity?
**Refer to your onenote. Sorry I couldn’t figure out how to paste this image
What is the respiratory quotient (RQ)?
What is the RQ for:
fat
glucose
protein?
What RQ value indicates overfeeding?
RQ = CO2 production / oxygen consumption
Fat RQ = 0.7
Glucose RQ = 1.0
Protein RQ = 0.8
RQ > 1 = overfeeding
How does nitric oxide affect the pulmonary system?
Causes vasodilation of pulmonary capillaries that take it up, thereby shunting blood toward healthy alveoli and away from damaged alveoli.
What are the effects of Dopamine at low, moderate, and higher doses in the body?
At low doses (1-3 mg/kg/min), increases renal blood flow and maintain diuresis through DA1 and DA2 receptors stimulation in the renal vasculature.
At moderate doses (5-10 mg/kg/min), increases contractility and cardiac output via stimulation of cardiac β-receptors.
At higher doses (> 10mg/kg/min), peripheral vasoconstriction from increasing α-activity becomes more prominent, resulting in elevation of systemic vascular resistance and blood pressure.
What is the mechanism of Dobutamine?
What is the predominant effect?
What effects does it have on peripheral vasculature?
Low dose effects
(and which adrenergic effects predominate)?
High dose effects
(and which adrenergic effects predominate)?
β-adrenergic effects without any α-activity.
The predominant effect is an increase in cardiac contractility with little increase in heart rate from β1 stimulation.
Dobutamine also has a peripheral vasodilating effect resulting from β2-receptor activation.
Low dose - B1 - increase cardiac contractility
High dose - B2 - vasodilation
What is the mechanism of Norepinephrine?
Low dose effects
(and which adrenergic effects predominate)?
High dose effects
(and which adrenergic effects predominate)?
Norepinephrine exerts both α- and β1-adrenergic effects.
At lower doses, the β1-adrenergic effects are most prominent leading to increases in heart rate and contractility.
At higher doses, the α-adrenergic effect becomes evident and are responsible for increases in systemic vascular resistance and blood pressure.
What is the mechanism of Epinephrine?
Low dose effects
(and which adrenergic effects predominate)?
High dose effects
(and which adrenergic effects predominate)?
Both α- and β-adrenergic receptors.
At lower doses, increase in heart rate and contractility (β1-effect) in conjunction with peripheral vasodilation (β2-effect)
At higher doses, α-effects predominate, leading to an increase in systemic vascular resistance and blood pressure.
What is the mechanism of Atropine?
What does it treat?
What is the half-life? Where is it metabolized?
Competitive inhibition of muscarinic receptors - reverses parasympathetics
Treats bradycardia, acetylcholinesterase poisoning.
Half-life 2-3 hours and metabolized by liver.
What is mechanism of Milrinone?
What is used to treat?
Phosphodiesterase type III inhibitor - pulmonary vessel dilation and cardiac contractility agent
Useful in pulmonary hypertension or cardiogenic shock
Works by blocking the degradation of cAMP
What are 4 nutritional markers and their half lives?
1) Retinol binding protein - 12 hours - also negative acute phase reactant…decreases during stress
2) Pre-albumin (preferred in ICU) - 2 days - also negative acute phase reactant…decreases during stress
3) Transferrin - 10 days
4) Albumin - 20 days
What are effects of Magnesium and PTH when levels are low?
Levels are high?
When low, decreases end organ response to PTH and can suppress PTH release.
If High, can bind to Calcium sensing receptor on parathyroid gland and make it think calcium is high, suppressing PTH.
What are the ECG changes seen in . . .
Hypokalemia?
Hypomagnesemia?
U wave, flat or inverted T waves (K < 3.0)
Wide QRS
Flattening of T waves
Prolonged PR
Polymorphic ventricular tachycardia
Indications for dialysis?
AEIOU
Acidosis, Electrolyte imbalances, Intoxication, Overload, Uremia
GFR 10-15 in a patient with symptoms
GFR < 5 in asymptomatic patient
CrCl < 25, Cr > 4
