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108 Cards in this Set
- Front
- Back
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approximately what percent of cardiac output do the kidneys receive?
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25%
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approximately what percent of the cardiac output does the brain received?
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15%
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what is the effect of heart rate on cardiac output?
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Cardiac output increases with increasing heart rate, but after about 150 bpm the cardiac output starts to decrease due to decreased diastolic filling time
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what is the effect of increased after load on the contractility?
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Increased after load causes an automatic increasing contractility to try to overcome the increased after load Anrep effect
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what is the effect of tachycardia on contractility?
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Tachycardia causes an automatic increase in contractility known as the Bowditch effect
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which systolic pressure is higher radial or aortic?
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Radial due to the difference in size
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what ranges normal cardiac output?
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4 to 8 L per minute
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how is the mean arterial pressure calculated?
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Cardiac output times systemic vascular resistance
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how is the ejection fraction calculated?
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Stroke volume divided by in diastolic volume
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is the consumption of oxygen by the body dependent of the oxygen supply?
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No oxygen's consumption by the body is generally independent of the oxygen's life, unless very low levels are reached in the body will start consuming less oxygen
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what is the effect of a right shift in the oxygen disassociation curve?
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Hemoglobin of the decreased affinity for oxygen
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what is the effect of 2, 3 DPG on the oxygen disassociation curve?
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right shift
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what is the effect of acidosis on the oxygen disassociation curve?
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Right shift
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what is the effect of elevated CO2 levels on the oxygen disassociation curve?
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Right shift
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what is the effect of increased body temperature on the oxygen disassociation curve?
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Right shift
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what is the P 50?
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The oxygen tension at Sa02 of 50%
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what is normal central venous pressure?
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Approximately 7 millimeters of mercury
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what is a normal P50?
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approximally 27 millimeters of mercury
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what is the normal Venus at Sa02?
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70%
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what three things affect the mixed venous O2?
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hemoglobin, cardiac output, and tissue demand/extraction
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how does cardiac output decreased mixed venous O2?
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Decrease in cardiac output will increase O2 extraction from the capillaries and therefore decreased mixed venous O2
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what is the effect of sepsis or hypothermia on mixed venous O2?
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Sepsis and hypothermia cause a decrease in oxygen extraction by the tissues and therefore cause an increased mixed venous O2
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what is normal pulmonary capillary wedge pressure?
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11 mmHg
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what is the only method of measuring pulmonary vascular resistance?
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Swan Ganz catheter
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in which zone of the long should a Swan-Ganz catheter be placed?
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Zone three lower lungs
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what should be done if hemoptysis results as a result of a Swan-Ganz placement?
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Pull the Swan-Ganz catheter a bit, inflate the balloon, and increase PEEP to tamponade pulmonary artery bleed
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what are the main determinants of myocardial oxygen consumption?
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Increased ventricular wall tension and heart rate
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is there a PO2 difference between blood leaving the lungs and blood of the left atrium?
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Yes because bronchial veins drain into the pulmonary vein. There is a small PO to drop between blood leaving the alveoli the blood reaching the left atrium
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which vessel carries blood with the lowest O2 saturation?
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Coronary venous blood, due to the high myocardial oxygen extraction
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what is the cause of neurogenic shock?
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Decreased sympathetic tone
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what is the treatment of neurogenic shock?
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Fluid resuscitation, and possibly vasopressors
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hypotension that is unresponsive to fluids and pressers is indicative of what?
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Adrenal insufficiency
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what is the next step in management of a hypotensive patient unresponsive to fluids and pressers?
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Steroid stress test
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which steroid is the most potent?
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Dexamethasone
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what is Becks triad of cardiac tamponade?
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Hypotension, jugular venous distention, and muffled heart sounds
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what is the first echocardiogram finding of cardiac tamponade?
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Impaired diastolic filling of the right atrium
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which type of shock is the only type with increased cardiac output?
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Septic shock, though severe septic shock with increased cardiac workload can lead to cardiogenic shock with decreased cardiac output
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which two types of shock are the only types with increased systemic vascular resistance?
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Cardiogenic and hemorrhagic
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which is the only type of shock with increased CVP?
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Cardiogenic
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what is the mechanism of action of activated protein C ( Xigris) in sepsis?
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Anti-inflammatory by blocking TNF production, as well as fibrinolytic
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other than hypoxia, what are other possible signs of fat embolism?
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Petechiae and confusion
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what type of stain of sputum or urine can indicate fat embolism?
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Sudan red stain
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which signs and symptoms with pulmonary embolism carry worse prognosis?
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shock, tachycardia, tachypnea
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what is the treatment of pulmonary embolism and shock?
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Thrombolytics or embolectomy
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what is the treatment of pulmonary embolism and right ventricular strain on echocardiogram?
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Echocardiogram will most always show right ventricular strain in the setting of pulmonary embolism. Treatment should therefore be no different than any other case of pulmonary embolism unless the patient is in shock
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when do intra-aortic balloon pump to inflate?
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On diastole, triggered by the T wave
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when do intra-aortic balloon pumps deflate?
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On systole, triggered by P or Q wave
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when our intra-aortic balloon pump is useful?
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Cardiogenic shock, (MI, CABG)
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how are intra-aortic balloon pump's useful?
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They decrease the after load and improve coronary perfusion
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when are intra-aortic balloon pump contraindicated?
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Aortic regurgitation
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where should the tip of the intra-aortic balloon pump catheter be?
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Distal to the left subclavian
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what is the effect of dopamine at 0-5 micrograms per kilogram per minute?
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Dopamine receptors only, hence renal artery dilation
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what is the effect of dopamine at 6-10 micrograms per kilogram per minute?
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Beta adrenergic receptor, hence increased heart rate and contractility
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what is the effect of dopamine at greater than 10 µg per kilogram per minute?
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A adrenergic receptor, hence vasoconstriction
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what is the effect of dobutamine at 5-15 micrograms per kilogram per minute?
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Beta-1 receptor, hence increased heart rate and contractility
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what is the effect of dobutamine at greater than 15 µg per kilogram per minute?
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Beta-2 receptor, hence vasodilation
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what is the mechanism of action of milrinone?
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PDE inhibitor, therefore causing an increase in cyclic TMP and hence increased calcium influx into cells and increased contractility
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what is the mechanism of phenylephrine?
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Alpha-1 agonist, hence vasoconstriction
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what is the effect of low-dose norepinephrine?
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Beta-1 agonist only
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what is the effect of high-dose norepinephrine?
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A and beta-1 agonist
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what is the effect of low dose epinephrine?
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Beta-1 and beta-2 agonist, due to the beta-2 low dose epinephrine can actually cause hypotension
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what is the effect of high-dose epinephrine?
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Alpha and beta agonist
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what is the mechanism of action of isoproterenol?
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beta-1 and beta two agonist. basically the same effect as low dose epinephrine
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what is the mechanism of action of vasopressin?
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V1 and V2 receptor agonist
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what does the V1 receptor do?
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Vasoconstriction
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what does the V2 receptor do?
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Water reabsorption in the collecting ducts, as well as promote von Willebrand factor and clotting factor VIII release from the endothelium
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what is the mechanism of action of sodium nitroprusside?
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arterial and venous dilation
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what is the side effect of high-dose sodium nitroprusside?
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cyanide toxicity
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what is the treatment of cyanide toxicity?
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Amyl nitrate initially, followed by sodium nitrite and lastly sodium thiosulfate
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what is the side effect of nitrites?
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Methemoglobinemia, oxidized FE +3 heme
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what is the treatment of methemoglobinemia?
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Methylene blue
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what is the mechanism of action of nitroglycerin?
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Venous dilation, it decreases the cardiac workload by decreasing preload
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why is the SaO2 not a reliable marker in carbon monoxide poisoning?
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pulse oxygen saturation readers cannot detect hemoglobin that is bound to oxygen from that down to carbon monoxide. Carbon monoxide poisoning can give a normal SaO2 reading
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what is the treatment of carbon monoxide poisoning?
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100% oxygen
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what is compliance?
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Change in volume over change of pressure
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what happens to long compliance in ARDS or pulmonary fibrosis?
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Decreases
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which part of the lungs have the highest V/Q ratio?
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The upper lobes
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what are the F I 02, PEEP, RR, PO2, PCO2 parameters for ventilator weaning?
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FIO2 less than 40%, PEEP five, RR less than 24, PO2 greater than 60, PC 02 less than 50
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how does PEEP improve oxygenation?
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alveoli recruitment
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what factors increase the risk of Barotrauma?
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peak long pressures greater than 54 for > 12 hoursand plateau pressure greater than 30
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what is the functional residual capacity?
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Expiratory reserve volume, title volume, and expiratory reserve volume
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what is vital capacity?
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Inspiratory reserve volume, title volume, and expiratory reserve volume
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what is the effect of obstructive lung diseases on the FEV/FRC?
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Decreases FEV/FRC, low FEV, and high FRC so the ratio is low
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what is the effect of restrictive lung diseases on FEV/FRC?
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Increased FEV/FRC, all the long volumes including FRC are decreased and hence the ratio ends up being higher
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what is the most common cause of ARDS?
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sepsis
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what is the PaO2: FIO2 requirement for the diagnosis of ARDS?
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PaO2: FlO2 less than 200
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what is the pulmonary arterial wedge pressure requirement for the diagnosis of ARDS?
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PAWP less than 18, because otherwise the bilateral pulmonary infiltrates could possibly be due to left ventricular hypertrophy
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how do we calculate the partial pressure of the gas?
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(Barometric mmHg - water vapor mmHg) x % of the gas. So for oxygen for example ( 760-47) x 0.21 = 150mmHg
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what is Mendelson's syndrome?
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Chemical pneumonitis from aspiration of gastric secretions. The pH of the aspirate is associated with the degree of damage, higher acidity causes more damage
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what is the most common cause of atelectasis?
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Bronchial obstruction
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what are the risk factors for atelectasis?
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COPD and obesity
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what is the best test to diagnose the cause of azotemia?
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Fractional excretion of sodium FeNa
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how is the fractional excretion of sodium calculated?
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Urine sodium divided by creatinine divided by plasma sodium divided by creatinine
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what is the urine sodium in prerenal azotemia?
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Less than 20
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what are the six indications for dialysis?
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Fluid overload, hyperkalemia, metabolic acidosis, uremic encephalopathy, uremic coagulopathy, and poisoning
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which cells release Renin?
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juxtaglomerular cells,in response to low blood pressure or by beta-1 stimulation?
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what does renin do?
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converts angiotensinogen to angiotensin one
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what does angiotensin-converting enzyme do?
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Converts angiotensin 12 angiotensin two
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what does angiotensin to do?
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Stimulate aldosterone release and also causes vasoconstriction
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we are is atrial natriuretic peptide released from?
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released from the atrial wall, in response to atrial distention
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what does atrial natriuretic peptide do?
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inhibit sodium and water reabsorption in the collecting ducts
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which cells produce antidiuretic hormone ADH?
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supra-optic cells of the posterior pituitary
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what is the main stimulus for ADH release?
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high serum osmolarity
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how do NSAIDs cause renal damage?
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inhibit prostaglandin synthesis, and therefore result in renal arteriole vasoconstriction
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what factors exclude the diagnosis of brain death?
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uremia, hypothermia, hypotension, sedation medications, and metabolic derangements
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what is carboxyhemoglobin?
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carbon monoxide bound to hemoglobin
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what levels are abnormal carboxy hemoglobin?
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> 10 % or >20% in smokers
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what is the treatment of diabetic ketoacidosis?
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insulin, potassium, IV fluids, bicarb to keep pH greater than 7.2
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