Otterbein/Grant CRNA Basics Midterm Review - Machine

Methemoglobinemia can cause inaccurately high SpO2 readings (if <85%) with cyanosis. Methemoglobin is unable to adequately transport oxygen. Normally, there is about 1% of metHgb present from the breakdown of hgb molecules. MetHgb absords red and infrared light equally.

Increasing the FGF (fresh gas flow) helps to remove the expired CO2 from the breathing system and replace it with fresh gas. If the inspired CO2 reading returns to 0 after increasing the FGF, it suggests that the problem was an exhausted absorbent. The absorbent in the breathing system is responsible for removing CO2, and when it becomes exhausted, it cannot effectively remove CO2 from the inspired gas. Therefore, the statement "You suspect that the problem was an exhausted absorbent, not your unidirectional valve" is true.

Food & Drug Administration

The given correct answer is "Low." In this context, the question is asking about the pressure system that includes everything beyond the flowmeter needle valve. The term "low" suggests that the pressure in this system is low, indicating that the pressure is reduced or regulated after passing through the flowmeter needle valve.

The most common site for disconnection in a breathing circuit is between the breathing tube and the Y piece. This is because this connection is frequently manipulated during patient care, such as when changing the patient's position or adjusting the breathing tube. The frequent manipulation increases the risk of accidental disconnection at this site, leading to a potential interruption in the delivery of oxygen or ventilation to the patient.

The given statement describes the Joule-Thompson Effect. When a compressed gas is allowed to escape freely, it undergoes an adiabatic process, meaning there is no exchange of heat with the surroundings. As the gas expands, it does work against the external pressure, causing a decrease in temperature. This phenomenon is known as the Joule-Thompson Effect, which is commonly observed in various applications such as refrigeration systems.

The compliance of the circuit is a measure of how easily it expands or contracts in response to pressure changes. In this case, the compliance is 3 mL/1 cmH2O, meaning that for every 1 cmH2O increase in pressure, the circuit expands by 3 mL. The PIP (Peak Inspiratory Pressure) is given as 30 cmH2O. To calculate the volume that is not reaching the patient, we can multiply the compliance by the PIP. So, 3 mL/1 cmH2O * 30 cmH2O = 90 mL. Therefore, 90 mL of volume is being delivered to the circuit but not reaching the patient.

This capnogram is showing cardiac oscillations. A capnogram is a graphical representation of the concentration of carbon dioxide in exhaled breath over time. Cardiac oscillations refer to the rhythmic fluctuations in the capnogram waveform that are caused by the beating of the heart. These oscillations are typically seen as small, regular waves superimposed on the main capnogram waveform. They can provide valuable information about the patient's cardiac function and can be used to monitor changes in cardiac output during procedures or in critical care settings.

Ketamine is not known to cause methemoglobinemia. Methemoglobinemia is a condition where the iron in hemoglobin is converted to a non-functional form, resulting in reduced oxygen-carrying capacity of the blood. Nitrobenzenes, benzocaine, prilocaine, and dapsone are all known to cause methemoglobinemia. However, ketamine does not have this side effect.

The hanger yoke, yoke block with check valves, and the cylinder pressure gauge and regulators are all components that are typically associated with a high pressure system. These components are designed to handle and regulate high pressure levels, which is why they are not part of the intermediate or low pressure systems. The Mapleson circuit is a different type of system altogether, so it is not the correct answer in this case.

The correct answer is to increase FGF. FGF stands for Fresh Gas Flow, which refers to the amount of fresh gas delivered to the patient during anesthesia. Increasing the FGF helps to flush out the excess CO2 and maintain a lower inspired CO2 level. This intervention is necessary to ensure proper ventilation and prevent complications associated with elevated CO2 levels. Switching to APL mode, replacing CO2 granules, or activating ECMO STAT are not appropriate interventions in this scenario.

In the scenario where FGF (Fresh Gas Flow) is greater than TV (Tidal Volume), no rebreathing will occur. This means that the amount of fresh gas being supplied is sufficient to meet the patient's respiratory needs, and there is no need for the patient to inhale any exhaled gas. This helps prevent the accumulation of carbon dioxide and ensures an adequate supply of oxygen for the patient.

Bernoulli's law states that as the speed of a fluid increases, the pressure exerted by the fluid decreases. This is because the total energy of the fluid, which includes potential energy and kinetic energy, remains constant. As the fluid flows faster, its kinetic energy increases, leading to a decrease in potential energy. This decrease in potential energy is manifested as a decrease in pressure. Therefore, Bernoulli's law explains the relationship between fluid speed and pressure.

The correct answer is 1590. An E cylinder is a specific type of gas cylinder that is commonly used for medical purposes. It has a capacity of 1590 liters when full, which means that it can hold up to 1590 liters of N2O gas when it is pressurized at 745 psi. This information is important for medical professionals who need to accurately measure the amount of gas available in the cylinder for various procedures.

The alpha angle in capnography occurs between phase 2 and phase 3 and is normally 100-110 degrees. It increases with COPD due to prolonged emptying related to obstruction to outflow. This statement is true because it accurately describes the relationship between the alpha angle and COPD.

Ascending bellows provide a positive end-expiratory pressure (PEEP) due to the weight of the bellows itself. This means that during expiration, the bellows exerts a constant pressure on the patient's airways to prevent them from collapsing completely. The pressure of this PEEP is typically between 2-4 cmH2O.

The given equation CO2 + H2O = H2CO3 represents the reaction between carbon dioxide and water to form carbonic acid. This reaction is commonly known as the first neutralization reaction because it involves the combination of an acid (CO2) and a base (H2O) to form a new compound (H2CO3) which is considered neutral.

The cylinder pressure after the 1st stage regulator is lower compared to the pipeline pressure. This is because the 1st stage regulator is designed to reduce the pressure of the gas coming from the pipeline to a lower, more manageable level for use in the cylinder. The pipeline pressure, on the other hand, is the initial pressure of the gas before it goes through any regulation or reduction. Therefore, the cylinder pressure after the 1st stage regulator is lower than the pipeline pressure.

The capnogram is showing a "Curare cleft." Curare is a medication used during anesthesia that can cause a decrease in muscle strength, including the muscles involved in breathing. A curare cleft refers to a dip or decrease in the capnogram waveform, indicating a decrease in the amount of exhaled carbon dioxide. This can be seen as a result of the effects of curare on the respiratory muscles.

The correct answer is 12.5 kPa (125 cmH2O). This is the limit to which the pressure in the breathing circuit of an anesthesia machine is set. It is important to maintain a safe and controlled pressure in the breathing circuit to ensure the patient's safety and prevent any harm. The anesthetist sets this limit to ensure that the pressure does not exceed a certain threshold that could be detrimental to the patient's respiratory system.

The beta angle in capnography exists between phase 3 and phase 4. It represents the angle between the inspiratory and expiratory curves on the capnogram. Normally, the beta angle is approximately 90 degrees. However, if there is rebreathing or obstruction to inspiration, the beta angle can increase. Therefore, the given statement is true.

The required component of flowmeters is a uniquely shaped O2 flow knob. This suggests that the flow knob for oxygen flowmeters should have a distinct shape that sets it apart from other flow knobs. This is important for easy identification and differentiation of the oxygen flowmeter from other gas flowmeters.

Reduced (deoxygenated) hgb absorbs more in the RED band - 660 nm.

The National Fire Protection Association (NFPA) is a regulatory body that sets standards and guidelines for fire safety. They have regulations in place for various systems and equipment, including piped vacuum systems. Therefore, it is true that the NFPA regulates piped vacuum systems.

The critical temperature of a substance is the highest temperature at which it can exist as a liquid. In this case, the critical temperature of O2 is -119 degrees Celsius. This means that at temperatures below -119 degrees Celsius, O2 can exist as a liquid, but at or above -119 degrees Celsius, it will either be a gas or a solid.

Vanometer = expiratory
Inspired O2 analyzer = Inspiratory

Pulse oximetry is a non-invasive method used to measure the oxygen saturation level in the blood. However, one of its disadvantages is the delay in reading, which can be up to 15 seconds. This means that there may be a delay in accurately determining the oxygen saturation level, which could be crucial in certain medical situations. It is important to consider this delay when using pulse oximetry as a diagnostic tool or monitoring device.

The oxygen flush valve, while providing a high flow of oxygen, can increase the risk of intraoperative awareness by diluting inhaled anesthetic agents. This is because the high flow can wash out the anesthetic agents from the breathing circuit, potentially leading to inadequate anesthesia. Additionally, the high flow of oxygen from the flush valve can also place the patient at risk for barotrauma, which is an injury caused by excessive pressure in the lungs. Therefore, the use of the oxygen flush valve should be carefully monitored to minimize these risks.

The FiO2 (Fraction of Inspired Oxygen) is the percentage of oxygen in the inspired air. In this case, the total volume of gas administered is 4L of N2O, 1L of O2, and 1L of air, which amounts to 6L. Since the question does not specify the percentage of oxygen in the air, we assume it to be 21% (which is the normal concentration of oxygen in air). Therefore, the total volume of oxygen in the gas administered is 1L (from the O2) plus 0.21L (from the air), which equals 1.21L. To calculate the FiO2, we divide the volume of oxygen by the total gas volume and multiply by 100, resulting in a FiO2 of 20%.

Remember:
Controlled : Dead Bodies Can't Argue = D > B > C > A
Spontaneous: All Dogs Can Bite = A > D > C > B

The hazards of central gas supplies include crosses pipelines, damage to pipelines during construction, and foreign substances in the pipeline. Crosses pipelines can lead to leaks and accidents. Damage to pipelines during construction can cause gas leaks and potential explosions. Foreign substances in the pipeline can contaminate the gas supply and pose health risks.

When the FGF (Fresh Gas Flow) is very high in a circuit, it means that a large amount of fresh gas is being delivered to the patient. This high FGF helps to remove the exhaled carbon dioxide (CO2) from the circuit more efficiently, resulting in a decrease in the partial pressure of CO2 in the patient's arterial blood (PaCO2). Therefore, when the FGF is high, the PaCO2 becomes more dependent on ventilation, particularly during spontaneous respiration. This means that the rate and depth of breathing play a crucial role in regulating the PaCO2 levels in the body.

The correct answer includes three standards that should be met for pulse oximetry. Firstly, accuracy must be stated, indicating that the device should provide accurate readings. Secondly, there should be a variable pitch following the SpO2 reading, which can help in alerting healthcare professionals to changes in oxygen saturation levels. Lastly, the device must have an alarm for low SpO2, typically set around 90%, to notify when oxygen levels are dangerously low.

A combination pressure relief device is designed to release excessive pressure and heat in a medical gas cylinder. It is a safety mechanism that helps prevent the cylinder from exploding or causing any harm. This device is specifically designed to respond to both excessive pressure and excessive heat, making it an effective safety measure in medical settings.

Compound A formation:
Decreased with higher flows
More is produced with potassium or sodium hydroxide absorbents compared to calcium
Increased sevo concentration and length of case produces more compound A.
Dehydrated absorbent increases compound A production.

When there is a mixture of N2O and halogenated agents in the OR, the allowable trace gas level for N2O remains the same at 25 ppm. However, the allowable trace gas level for halogenated agents decreases to 0.5 ppm.

When minute ventilation exceeds the fresh gas flow (FGF) in a circuit, the partial pressure of carbon dioxide (PaCO2) is dependent on the FGF. This means that the amount of carbon dioxide in the circuit is determined by the rate at which fresh gas is flowing into the system. If the FGF is lower than the minute ventilation, the PaCO2 will increase because the circuit is not able to remove carbon dioxide from the system as quickly as it is being produced. Therefore, the FGF plays a crucial role in regulating the PaCO2 levels in the circuit.

The APL valve is the only control on the anesthesia machine that uses a clockwise rotation.

The CO2 absorbent canister should be filled up to 50% of its capacity. This is because the canister needs to have enough space to absorb the carbon dioxide efficiently. If the canister is filled completely, there won't be enough room for the CO2 to be absorbed, and if it is filled too little, the absorption capacity will be underutilized. Therefore, filling the canister up to 50% ensures optimal absorption of CO2.

The critical temperature of a substance is the temperature above which it cannot exist as a liquid, regardless of the pressure applied. In this case, the critical temperature of N2O is 39.5 degrees Celsius. This means that at temperatures higher than 39.5 degrees Celsius, N2O will only exist as a gas, regardless of the pressure.