Chapter One
1. The equation of state of a real gas. The physical meaning of the two correction quantities of a and b.
a is a correction related to the gravitational force between molecules; b is a correction related to the volume occupied by gas molecules.
2. The physical meaning of critical constants TC, PC, VC.
TC - critical temperature, the highest temperature limit of gas relying on compression liquefaction.
PC----Critical pressure is the pressure required to liquefy the gas at the critical temperature, that is, the maximum limit of the saturated vapor pressure.
VC----Critical specific volume is the maximum volume of a unit mass of liquid when it expands under reduced pressure.
3. The relationship between the solubility of anesthetic gas in blood and the speed of anesthesia induction and awakening.
For anesthetics with low solubility, the partial pressure in the blood rises quickly, and the time for the partial pressure in the alveoli, that is, the partial pressure in the brain to reach equilibrium after inhalation is short, so the induction is rapid. Moreover, due to the low solubility in the blood, once excreted, it will disappear from the body quickly, so it will wake up quickly.
4. What are the two methods of gasification? What's the difference?
There are two ways of gasification: evaporation and boiling . Evaporation is the phenomenon of vaporization on the surface of the liquid , and boiling is the phenomenon of vaporization on the surface and inside of the liquid at a certain temperature .
5. What factors are related to the saturated vapor pressure? Vaporization characteristics of volatile liquid anesthetics.
Saturation vapor pressure is temperature dependent. The characteristics of vaporization of volatile anesthetics are: low boiling point , small heat of vaporization , high saturated vapor pressure , and easy vaporization .
6. What is the liquefaction process? How to liquefy a gas?
The process of a substance changing from a gaseous state to a liquid state is called liquefaction. Gas liquefaction can be achieved by cooling and pressurizing (below the critical temperature, above 50 atmospheres) .
7. The definition of gas solubility and what factors are related to the improvement of solubility.
Under certain temperature and pressure conditions, when the gas on the liquid surface and the dissolved gas reach a dynamic equilibrium, the concentration of the gas in the liquid is called solubility. Increased solubility is related to temperature and pressure
8. Andrews experiment
It is known that this experiment is a systematic isothermal compression test of carbon dioxide at different temperatures to observe the state change process of the gas. Leads to the concept of critical temperature, critical pressure and critical specific volume
Chapter two
1. What is an artificial airway?
Artificial airway is the general term for the final pipeline connection between the anesthesia machine or ventilator breathing airway and the patient's anatomical airway.
2. When the double-lumen airway is used, after the double airbags are inflated, under what circumstances will the outer lumen be ventilated? When is endoluminal ventilation used?
If the front end enters the esophagus , the double cuff is inflated and ventilated through the outer lumen ; if the front end enters the trachea , it can be ventilated through the inner tube .
3. What are the three types of double-lumen bronchial catheters?
Cullens double-lumen tube, White double-lumen tube and Robert Shaw double-lumen tube.
third chapter
1. The function and working principle of the pressure reducing valve.
Function: reduce the high and changing pressure in the gas storage valve to a low and stable pressure.
How it works: Diffusion decompression
2. What are the characteristics of the ventilation functions of the Mapleson A and D systems?
The Mapleson A system is used for spontaneous breathing; the Mapleson D system is used for controlled breathing.
3. What do semi-open systems and closed systems rely on to remove carbon dioxide?
The semi-open system relies on fresh gas to remove CO2, and the semi-closed system relies on the CO2 absorber to remove CO2.
The function of the one-way valve is to control the direction of the respiratory airflow.
4. Simply draw the air circuit and anesthesia circuit diagram of the main engine of the anesthesia machine, and mark the names of the main components . (draw by yourself)
5. The basic working principle of the anesthesia vaporizer, which two factors determine the output concentration?
The gas source supplies a certain flow of gas. After entering the evaporator, it is divided into two paths. The path passing through the bypass is called the dilution airflow, and the path entering the evaporation chamber is called the carrier gas. The anesthetic vapor taken away by the carrier gas merges with the dilution airflow at the outlet to become an anesthetic mixed gas containing a certain concentration of anesthetic vapor.
6. The main factors affecting the output concentration of the evaporator; ( the decisive factors are the split ratio and saturated vapor pressure )
①Temperature: The liquid evaporates, the temperature drops, the saturated vapor pressure also drops, and the output concentration decreases.
②Contact area between carrier gas and liquid medicine: the larger the surface area, the more evaporation per unit time; otherwise, the less evaporation.
③ Intermittent reverse pressure effect: reverse pressure (pumping effect) can increase or decrease (pressure effect) the output concentration of the evaporator.
④ Influence of dilution air flow and carrier gas split ratio: The split ratio of the evaporator depends on the ratio of the air resistance of the dilution channel to the carrier gas channel.
7. How does the pumping effect come about? How to overcome it?
(1) Causes: ① During the inspiratory period, the normal split ratio of the carrier gas and the dilution airflow is destroyed. ② During the exhalation period, the anesthetic vapor in the evaporation chamber will flow into the bypass from the entrance of the evaporator, so that the diluent gas will carry the anesthetic.
(2) Overcoming methods: ① Reduce the space above the liquid in the evaporation chamber and increase the size of the bypass channel; ② Use a spiral large-diameter hollow pipe to connect to the evaporation inlet; ③ Install a low-pressure one-way valve at the outlet of the evaporation chamber; ④ Increase the resistance at the outlet of the evaporation chamber.
8. What are the two methods of temperature compensation?
(1) Heating type: ①direct heating (Tec6 evaporator); ②indirect heating (using the principle of chemical heat, setting adsorbent-activated carbon around the evaporation chamber, using its high heat absorption and heat release performance to provide heat source .now utilizes bulk bronze as an indirect heat source).
(2) Flow adjustment type: change the split ratio (for Vapor19 evaporator ----, reduce the bypass dilution airflow and increase the airflow into the evaporation chamber).
9. What types are the evaporators of TEC4, TEC6, Vapor19.1, and Vapor2000?
Tec4 evaporators are variable bypass, blown-through, automatic temperature compensated evaporators .
Tec6 evaporator belongs to electric control, injection type, direct pressure type evaporator .
Vapor19.1 evaporator is a variable bypass, brushed, automatic temperature compensation evaporator .
The Vapor2000 evaporator is a variable bypass, brushed, automatic temperature compensation evaporator .
10. What are the determinants of the efficiency of the blowing type and the bubble passing type evaporator?
Blowing type: the contact area between the gas phase and the liquid phase , the speed of the carrier gas flow and the distance between the carrier gas flow and the liquid surface .
Bubble through type: bubble size , liquid volume and carrier gas flow rate
11. The definition of adjustment mode and evaporation mode is classified according to the structure of the evaporator in each mode;
The adjustment method of the ventilation flow refers to the path form adopted by the dilution air flow. Divided into bypass variable type and measured flow type .
Evaporation mode refers to the channel form used when the gas flows through the evaporation chamber, which is divided into brushing type , bubble passing type and injection type .
12. Features of closed loop breathing loop system
A semi-closed ventilation system becomes a closed ventilation system when the fresh air input is reduced to such an extent that the exhaust valve cannot be opened.
Main advantages: improved humidification, no pollution, saving fresh gas and general anesthetic, reducing heat loss, etc.
13. The role of pintle safety indicator system (PISS)
Used to prevent misinstallation of gas cartridges for different gases. Its basic structure is that there are two shaft holes with different sizes and different distances on the valve interface at the connection between various gas storage tanks and anesthesia machines, and there are two shaft pins with different sizes and different distances on the air inlet of the anesthesia machine. , only when the shaft hole and the shaft pin are completely consistent can they be connected to each other.
14. Describe the function of the air storage bag in the anesthesia ventilation system.
① Perform assisted or controlled breathing to provide sufficient air volume.
② Buffer and prevent damage to the lungs caused by high-pressure airflow.
③ It is convenient to observe the patient's respiratory frequency, amplitude and airway resistance.
④It is convenient for uniform mixing of anesthetic gas and oxygen.
⑤ It can expand the atrophied lung.
Chapter Four
1. How many types of ventilators are classified according to the clinical nature and the characteristics of each type?
| Features (★) |
Disadvantages (know) |
|
| Volume Preset Ventilator |
Keep tidal volume constant |
For patients with large changes in airway pressure and reduced compliance, the airway pressure rises too high, which is prone to airway pressure injury |
| pressure preset ventilator |
Ensure constant airway pressure. Good synchronization performance, less prone to pulmonary barotrauma |
Tidal volume, respiratory ratio, and respiratory rate are greater. For patients with reduced compliance, the tidal volume is reduced (insufficient air supply), which is likely to cause insufficient ventilation. |
2. The starting principle and exhalation switching principle of the ventilator.
(1) The mechanical operation of the ventilator from the exhalation state to the inhalation state is equivalent to the switching process of the ventilator from the resting state to the working state, which is called starting .
There are four principles of suction starting:
① Time start: When the exhalation time reaches the preset value, it will switch to inhalation. Unaffected by patient breathing behavior.
②Volume starting: the air storage of the bellows of the volume ventilation source reaches the predetermined capacity value, and the ventilation valve is opened to output gas. unaffected by the patient.
③Pressure start: The airway negative pressure signal caused by the patient's spontaneous inhalation triggers the start of inhalation. A ventilation cycle cannot be initiated while the patient is not breathing.
④Flow start: Inspiratory start triggered by the patient's inspiratory flow. Automatic cycle control cannot be achieved while the patient is not breathing. Applies only to the initiation of synchronized breaths.
(2) The mechanical operation of the ventilator from the inhalation state to the exhalation state is called exhalation switching .
There are four principles of exhalation switching:
① Time switching: Stop lung inflation according to the scheduled inspiratory time, without being affected by the patient's spontaneous breathing.
②Capacity switching: When the bellows exhaust of the capacity ventilation source reaches the predetermined capacity, the ventilation valve is closed to stop outputting gas. Not affected by the patient's spontaneous breathing.
③Pressure switching: The exhalation switch is triggered when the airway pressure reaches a predetermined value during the inhalation period, and the ventilation valve is closed to stop the output of gas. It has the effect of limiting the inspiratory pressure and can reduce the damage of high pressure in the lungs.
④ Air flow switching: It is the exhalation switching triggered by the patient's inspiratory flow falling to a predetermined value. Relatively sensitive.
3. What are the basic working parameters of the ventilator?
Ventilation frequency , tidal volume (Vt) and ventilation volume (MV) , peak airway pressure or inspiratory pressure and respiratory ratio (I:E) .
4. Ventilation characteristics and characteristic curves of the ventilation source.
P 96-100
5. What is the difference between pressure ventilation source and volume ventilation source?
| Basic structure |
output |
form of lung ventilation |
characteristic curve |
|
| pressure ventilation source |
Vent valve, flow regulating valve |
gas under pressure |
Release gas from high pressure to low pressure |
Determined by the output driving pressure Ps of the ventilation source |
| Volume Ventilation Source |
Deformation container, driving device |
It has the property of limited capacity, and there is no high pressure in the container |
Lung ventilation is accomplished as a volume transfer |
Determined by drive outside the container |
6. What is the difference between the output gas path of anesthesia ventilator and therapeutic ventilator?
(1) The anesthesia ventilator is not directly connected to the patient's airway
(2) The anesthesia ventilator does not split the output gas and the exhaust gas, and works in the way of back and forth airflow.
(3) The output gas is not directly used as the inhaled gas of the patient, and no humidification device is usually installed.
7. What are the two types of humidifiers, and the difference between them. installation location.
Humidifiers are divided into atomizers and humidifiers .
Nebulizer: Increase the water content of the gas in the form of mist droplets, without the heating effect of the gas, and can bring the solute in the water into the gas for inhalation treatment.
Humidifier: Increase the water content of the gas in the form of water vapor, humidify and heat at the same time, and the humidification effect is close to physiological.
Installation position: on the suction pipe
8. Characteristics of positive end-expiratory pressure (PEEP)
The phenomenon that the pressure in the respiratory airway is higher than the atmospheric pressure at the end of expiration is called positive end-expiratory pressure. PEEP can increase functional residual capacity and help improve lung ventilation.
9. In the ventilation mode of the ventilator, the difference between FVS and PVS.
Full Ventilatory Support (FVS) provides full inspiratory airflow. Partial ventilatory support (PVS) provides inspiratory flow in part.
FVS is invasive and PVS is noninvasive.
FVS is suitable for any patient; PVS is suitable for patients with spontaneous breathing, not for coma and respiratory failure patients.
10. Principles and adaptable objects of various ventilation modes
11. Common causes of ventilator high pressure and low pressure alarms.
Cause of airway high pressure alarm: The patient's airway is obstructed against breathing or the ventilator is seriously malfunctioning.
The origin of the air pressure drop alarm reason: the driving air source is exhausted, and the ventilator is about to lose its function.
Causes of airway low pressure alarm: Insufficient ventilation, breathing tube connection disconnected or ventilator stopped running.
chapter Five
1. Contents of regular inspection of the volumetric infusion pump.
(1) Inspection of the bubble detector
(2) Inspection of blocking pressure
(3) Inspection of flow rate accuracy
2. Classification of anesthesia and analgesia pumps.
Anesthesia analgesic pumps can be divided into two types : disposable non-electric analgesic pumps and electric analgesic infusion pumps according to the driving mode .
3. The driving mode of electronic analgesic pump and disposable analgesic pump.
(1) The driving force of the electronic analgesic pump comes from a stepping motor, which is driven by electricity;
(2) The one-time analgesic pump is driven by the elastic tension of the balloon.
Chapter Six
1. The working principle of the impeller type ventilation meter and the influence of tidal volume.
(1) Working principle: The gas blows the impeller to rotate in a tangential direction through the deflector, and converts the flow velocity of the gas into the rotational speed of the impeller. Within a certain measurement range, the rotational speed of the impeller is proportional to the gas flow rate, and the direction of rotation is related to exhalation or inhalation.
(2) The influence of tidal volume: Due to the inertia and friction between the bearings, the reading of the impeller type ventilator is too high at a high tidal volume, and the reading is too small at a low tidal volume.
2. The principle of blood oxygen saturation detector and the definition of blood oxygen saturation.
(1) Principle: Use the absorption characteristics of oxyhemoglobin HbO2 and reduced hemoglobin Hb to red light and infrared light. HbO2 absorbs more infrared light and lets more red light pass through, and Hb absorbs more red light and lets more infrared light pass through.
(2) Blood oxygen saturation (SPO2) is defined as: SPO2=HbO2/(Hb+HbO2) . It reflects the degree of hemoglobin and oxygen binding.
Chapter VII
1. Definition and classification of ECG leads.
(1) Definition: When measuring the electrocardiogram, the electrode placement position and the connection method between the wire and the amplifier are called electrocardiogram leads.
(2) Classification: standard limb leads (Ⅰ, Ⅱ, Ⅲ), pressurized unipolar limb leads (aVR, aVL, aVF) and unipolar chest leads (V1, V2, V3, V4, V5, V6 ).
Connection method: P 153-154
2. Methods and classification of blood pressure monitoring.
There are two methods of blood pressure monitoring: direct blood pressure monitoring (IBP) and indirect blood pressure monitoring (NIBP) .
According to the location of the baroreceptor, direct blood pressure monitoring can be divided into two types: fluid coupling method and catheter sensor method .
Indirect blood pressure monitoring is divided into five categories: palpation , auscultation , electronic Korotkoff sound automatic manometry , oscillometric method , and ultrasound Doppler automatic manometry .
chapter eight
1. Types of temperature scales.
At present, there are many temperature scales used in the world, including Fahrenheit temperature scale , Celsius temperature scale , thermodynamic temperature scale and international practical temperature scale .
3. Characteristics of NTC and PTC thermistors.
PTC----positive temperature coefficient thermistor whose resistance increases with temperature
NTC----Negative temperature coefficient thermistor whose resistance value decreases with the increase of temperature
5. Reasons for the loss of body temperature of patients during the operation and common measures to keep warm.
(1) The body temperature loss of patients during operation is mainly due to heat radiation , convection , evaporation and conduction .
(2) Measures to maintain the patient’s body temperature during surgery: ① control the ambient temperature; ② cover and isolate; ③ heat the liquid; ④ use a heating humidifier; The equipment includes infrared radiation heating instrument and compressed air convection blanket.
Chapter nine
1. What are the gas collection methods for medical gas monitoring? respective characteristics.
(1) Mainstream gas collection; (2) Side-flow gas collection; (3) Cut-off gas collection.
Comparing the three methods, the cut-off gas collection test results are closest to the arterial blood gas analysis results, but the cut-off gas collection can only be performed intermittently.
2. The clinical significance of different parts of the collection.
The patient's end-tidal gas and alveolar gas are the most reflective of the patient's physiological state and the level of anesthesia management .
3. Applicable objects for various gas analysis techniques.
(1) Electrochemical analysis technology: oxygen.
(2) Paramagnetic analysis technique: oxygen.
(3) Infrared analysis technology: gas molecules with more than two different elements (such as N2O, CO2 and halogen anesthetic gases)
(4) Other gas analysis techniques:
① Gas chromatography analysis technology: oxygen, carbon dioxide and volatile inhaled anesthetic vapor.
②Mass spectrometry technology: it can only detect preset gases.
③ Raman spectroscopy analysis technology: identify and detect almost all gases related to clinical anesthesia.
④ Piezoelectric crystal analysis technology: only one anesthetic gas can be detected.
⑤ Optical interference analysis technology: oxygen, carbon dioxide and volatile anesthetic gases.
4. Standard gas preparation method.
(1) Air and medical oxygen are ready-made standard gases for the oxygen meter
(2) Carbon dioxide standard gas often adopts air pressure gas distribution method
(3) The standard gas for inhaling anesthetics mostly adopts the volumetric gas distribution method
Chapter Eleven
1. Definition and principle of muscle relaxation monitoring.
(1) Definition: After clinical anesthesia patients use muscle relaxants, the monitoring of the nature and efficacy of neuromuscular blockade is called muscle relaxant effect monitoring.
(2) Principle: The motor nerve is electrically stimulated to cause contraction and myoelectric response to the muscles at the dominated part. The response is detected by the sensor element, and after amplification and analysis, the detection result indicates neuromuscular blockade. degree.
2. The difference between MMG muscle relaxation monitor and EMG muscle relaxation monitor.
The one that directly or indirectly detects the muscle contraction force is called the muscle mechanical contraction force type (MMG) muscle relaxation automatic detector; the one that detects the evoked muscle compound action potential is called the EMG type muscle muscle relaxation monitor.
3. Electrical stimulation for muscle relaxation monitoring.
① Single twitch stimulation; ② Tetanic stimulation; ③ Four clusters of stimulation; ④ Tetanic post count (PTC); ⑤ Double burst stimulation (DBS).
4. When placing the stimulating electrodes of the muscle relaxation monitoring instrument, the most suitable distance between the two electrodes.
The most suitable distance between electrodes is 2cm . If the distance is less than this distance, they will easily interfere with each other. If it exceeds 3cm, it will be difficult to obtain super strong stimulation current and 100% reference value.