Acheron: Instrumentation & Monitoring Flashcards
A tank containing nitrous oxide is colored:
A. Black
B. Green
C. Blue
D. Gray
E. Yellow
C. Blue
Fresh gas flow on an anesthesia machine is set to 1 L/min with 100% oxygen. The dial on an isoflurane vaporizer is set to 1.2%. What is the gas flow through the vaporizing chamber?
A. 12 mL/min
B. 38 mL/min
C. 54 mL/min
D. 62 mL/min
E. 100 mL/min
B. 38 mL/min
Variable bypass means the fresh gas flow through the vaporizer is split into — streams: one that flows through the vaporizing chamber (picking up anesthetic gas) and one that flows through the bypass chamber.
two
Saturated vapor pressures for sevoflurane, isoflurane, halothane, and enflurane are —, —, —, and — mm Hg.
160, 240, 243, and 170
Volatile agent concentration equation:
concentration = saturated vapor pressure/atmospheric pressure X 100%
A useful equation for calculating splitting ratios:
Flow through vaporizing chamber = Total FGF X [(Dial setting/100)/(Sat VP/Atm P)]
During the middle of an emergency surgery to treat an aortic dissection the main gas pressure supply alarm starts to sound. At this time you notice the EtCO2 increasing and the patient slowly starts to desaturate. After quickly attempting to diagnose the situation you are faced with you rapidly attach the manual resuscitator to the endotracheal tube and connect the supply tubing to the oxygen E-Cylinder. The surgeon states that he must continue the case. You are able to get a propofol infusion set up and check the tank to estimate how much time you have left running at 15 L/min oxygen flow rate. Assuming the current psig on the oxygen E-cylinder reads 1800, how many minutes do you have left with the tank?
A. 21 minutes
B. 39 minutes
C. 45 minutes
D. 73 minutes
E. 89 minutes
B. 39 minutes
Oxygen full volume and pressure?
Volume: 660L
Pressure: 2,000psig
Your 78 kg, 35 year old female patient having surgery for appendicitis is maintained on 2.1% sevoflurane for the duration of the case. What is the splitting ratio of gas flow through the vaporizing chamber to the flow through the bypass chamber of the vaporizer?
A. 1:5
B. 1:9
C. 1:10
D. 2:5
E. 2:7
B. 1:9
A 19 year old spastic quadriplegic with a history of gastroesophageal reflux disease, nephropathy and Buerger’s disease is in for hardware removal, cast application, hip osteotomy and bilateral hamstring lengthening. The patient weighs 40 kg, has no known drug allergies, and a starting hemoglobin of 15.6. The patient has been NPO since midnight. It is now 0800 and you are inducing the patient. Three hours later into the case and you have calculated the blood loss to be 300 mL. Assuming you have kept up with fluid replacement, what is the total amount of crystalloid that should have been administered to this patient?
A. 1240 mL
B. 1640 mL
C. 1780 mL
D. 1900 mL
E. 1880 mL
C. 1780 mL
As you attempt to mask ventilate a patient with an epic beard, you note the loss of significant amounts of gas due to leaking around the mask. In order to keep the reservoir bag full, you depress the oxygen flush valve. The oxygen flush valve provides what flow of oxygen (in liters per minute) directly to the common gas outlet?
A. 15 – 35
B .15 – 25
C. 35 – 75
D. 55 – 85
E. 75 – 90
C. 35 – 75
The oxygen flush valve delivers oxygen at a pressure of — psig at — L/min
50 ; 35-75
The oxygen flush valve allows bypassing of the flowmeters and vaporizers, and provides oxygen directly to the —.
common gas outlet
Additionally, use of the oxygen flush valve bypasses vaporizers and will cause anesthetic gas concentrations to —.
decrease
A manufacturing error allows for an empty isoflurane vaporizer to be accidently refilled with sevoflurane. A 35 year old healthy patient weighing 90 kg is induced with 50 mcg fentanyl, 100 mg of lidocaine, 200 mg propofol, and 100 mg succinylcholine. The endotracheal tube is placed without difficultly and the circuit is connected with 100% O2 and the isoflurane vaporizer set to 2% flowing at 5 L/min. Which of the following events is likely to occur 10 minutes later?
A. The surgeon complains that the patient is moving after incision
B. After incision, the patient remains still but shows an increased heart rate and blood pressure
C. The patient remains stable despite surgical incision
D. The patient’s blood pressure decreases significantly causing severe hypotension requiring treatment with 200 mcg phenylephrine
A. The surgeon complains that the patient is moving after incision
Actual sevo conc = 2% X (160 mm Hg/240 mm Hg) = 1.3% sevo
What dial setting on a desflurane vaporizer that has been calibrated at sea level will deliver 6% desflurane in Leadville, Colorado (elevation 10,000 ft with atmospheric pressure 69% of that at sea level)?
A. 4.2%
B. 5.6%
C. 6.0%
D. 7.8%
E. 8.7%
E. 8.7%
In order to calculate the required dial setting to deliver a certain concentration, use the following equation:
Required dial setting = Normal dial setting X (Calibration atmospheric pressure/Ambient pressure)
What system prevents inadvertent connection of a cylinder gas source to the incorrect anesthesia machine gas inlet?
A. Common gas manifold
B. Pin index safety system
C. Diameter index safety system
D. High pressure regulator
E. Yoke check valve
B. Pin index safety system
What is the oxygen content of a patient that has a hematocrit of 48, oxygen saturation of 100% and breathing an FiO2 of 65%?
A. 17.2 mL/dL
B. 19.4 mL/dL
C. 21.9 mL/dL
D. 23.1 mL/dL
E. 15.8 mL/dL
C. 21.9 mL/dL
Oxygen content equation:
CaO2 = (1.31 x Hb x SaO2) + (PaO2 x 0.003)
PaO2 estimation equation:
PaO2 can be estimated by FiO2 x 5
Which of the following statements is true regarding diffusion of gases in the lungs?
A. Fick’s Law of Diffusion states that diffusion of gases is inversely proportional to the difference in partial pressures of the gas
B. The uptake of nitrous oxide from the lungs to the blood is about 3 L/min
C. The much higher solubility of carbon dioxide allows it to diffuse across the alveolar membrane twenty times faster than oxygen
D. The concentration effect refers to the alveolar atelectasis that occurs after long periods of oxygen administration at very high FiO2
E. None of these are true
C. The much higher solubility of carbon dioxide allows it to diffuse across the alveolar membrane twenty times faster than oxygen
— states that diffusion is directly proportional to the difference in partial pressures of the gas.
Ficks Law
nitrous oxide diffused at a rate of — L/min
1
The much higher solubility of carbon dioxide allows it to diffuse across the alveolar membrane — times faster than oxygen.
20
A closed ventilator pressure relief valve can result in:
A. Barotrauma
B. Insidious escape of volatile agents into the operating theater
C. Decreased expiratory resistance
D. Damage to pipeline regulators regulator
E. Decreased ability to expand the lungs
A. Barotrauma
A 72 y/o male is scheduled for a colon resection s/d to colon cancer. The patient has a significant history for coronary artery disease, hypertension, diabetes mellitus, morbid obesity, and hyperlipidemia. The patient weighs 139 kgs and his starting Hb is 13.2 g/dL. What is this patient’s allowable blood loss?
A. 2359 mL
B. 2101 mL
C. 2205 mL
D. 1907 mL
E. 1705 mL
A. 2359 mL
