ANESTHESIA MACHINE

ANESTHESIA MACHINE

ANESTHESIA MACHINE

Anesthesia is a way to control pain during a surgery or procedure by using medicine called anesthetics. It can help control your breathing, blood pressure, blood flow, and heart rate and rhythm

WHAT IS ANESTHESIA?

1. Local anesthesia

2.General anesthesia

3.Regional anesthesia

TYPES OF ANESTHESIA

Local anesthesia is the temporary loss of sensation or pain in one part of the body produced by a topically applied or injected agent without depressing the level of consciousness.

LOCAL ANESTHESIA

General anesthesia is causing complete unconsciousness and relaxation of the entire body, as well as a loss of painful sensation. This type of anesthesia is often used for highly invasive surgeries or cases when total relaxation of the patient is required. The medicine may be given as a liquid in your IV. It may also be given as a gas through a face mask, endotracheal (end-o-tra-kee-ull) tube, or a laryngeal (luh-rin-g-ull) mask airway.

GENERAL ANESTHESIA

This is similar to local anesthesia, except that it covers a wider area of the body.

Anesthetic is injected around major nerves or the spinal cord. Regional anesthesia allows doctors to block sensations to

the entire lower body, or single limbs. Major types of regional anesthesia include: a. Peripheral nerve blocks. A nerve block is a shot of anesthetic near a specific nerve or group of nerves. It blocks

pain in the part of the body supplied by the nerve. Nerve blocks are most often used for procedures on the hands, arms,

feet, legs, or face.B. Epidural and spinal anesthesia: this is a shot of anesthetic near the spinal cord and the nerves that connect to

it. It blocks pain from an entire region of the body, such as the belly, hips, or legs.

Regional Anesthesia

BLOCK DIAGRAM

Principles of AnesthesiaThe most commonly used anesthetic is nitrous oxide used in combination with fluorocarbons, such as halothane, enflurane, methoxyflurane, etc. and oxygen. These are nonflammable.

This mixture is delivered to the patient on the inspiration cycle. The flow rate is correctly maintained by the flow meters in the each gas tubing (not shown in the figure). Exhalation passes through a one way valve, through a co2 absorber and is delivered again to the patient.

The anesthetic is constantly monitored and adjusted for the correct mixture by means by means of controlling circuits using flow meters like turbine flow meter or Rotameter. A portion of the anesthetic is exhausted and usually delivered to the outside through vent ducts.

Controls on the anesthesia Machine

1. System switch2. Flow controls3. Brake4. Light switch5. Light (some models)6. Dovetail rails7. O2 flush button8. Gauge (cylinder pressure)9. Gauge (pipeline pressure)10. Breathing system (figure 2-3)11. Vaporizers (figure 2-4)12. Ventilator/monitoring display

Panels of Anesthesia

1. System switch: it is used to permit the gas flow and to turn on the monitoring. The system switch must be on while using the system.

2. Flow controls: these controls are used to increase or decrease the gas flows. Turn the control counterclockwise to increase the flow and clockwise to decrease.

3. Break: it is used to stop the machine without moving. Push down to lock. Lift to release.

4. Light switch: used to turn the light on and off.

5. Light: used to give the brightness on the control panel.

6. Dovetail rails: these are used to give the support for machine controller.

7. O2 flush button: this button is used to supply high flows of O2 to the breathing system by pushing on it.

8. Gauge (cylinder pressure): it shows the pressure of gas in the cylinder.

9. Gauge (pipeline pressure): it will show the pressure of gases in pipeline which are coming from the gas plant.

10. Breathing system: it is used to deliver the gases to the patient.

11. Vaporizers: it convert liquid anesthetic into a volatile inhalation agent by using dalton’s law of pressure. Its vapor pressure equals atmospheric pressure.

12. Ventilator monitoring display: it displays the ventilator settings and inspiratory/expiratory wave. It also used to change the ventilator settings.

Explanation of control panels of Anesthesia

1 volume control mode

2 pressure control mode

Ventilation modes

1 volume control mode: volume control supplies a set tidal volume. The ventilator calculates a flow based on the set tidal volume and the length of the inspiratory time (T I) to deliver that tidal volume. It then adjusts that output by measuring delivered volumes at the inspiratory flow sensor. Since the ventilator adjusts output, it can compensate for breathing system compliance, fresh gas flow, and moderate breathing system leaks.

Explanation of Modes

Explanation of Modes

1 volume control mode: volume control supplies a set tidal volume. The ventilator calculates a flow based on the set tidal volume and the length of the inspiratory time (T I) to deliver that tidal volume. It then adjusts that output by measuring delivered volumes at the inspiratory flow sensor. Since the ventilator adjusts output, it can compensate for breathing system compliance, fresh gas flow, and moderate breathing system leaks.

A typical volume controlled pressure waveform increases throughout the entire inspiratory period, and rapidly decreases at the start of expiration. An optional inspiratory pause is available to improve gas distribution.

2.Pressure control mode : Pressure control supplies a constant set pressure during inspiration. The ventilator calculates the inspiratory time from the frequency and I:E ratio settings. A high initial flow pressurizes the circuit to the set inspiratory pressure. The flow then decreases to maintain the set pressure (P inspired). Pressure sensors in the ventilator measure patient airway pressure. The ventilator automatically adjusts the flow to maintain the set inspiratory pressure.Pressure control mode settings: • Pinspired (control pressure)• Rate• I:E• Plimit (pressure limit)• PEEP

Step1: Connect the power cord to a wall outlet. The mains indicator comes on when AC power is connected.

Step 2: Set the system switch to on (|).

Step 3 : The display shows the power-up screen, and the system does a series of self tests.

Step 4: When the self tests pass, the display shows the normal screen. If a test fails, the screen shows an alarm. Refer to the troubleshooting section.

Step 5: Select the required settings by using selection, menu keys and control

Operations of Anesthesia

For general anesthesia, pre anesthetic agents are administered 45 minutes to one hour before induction of anesthesia. Induction of anesthesia is usually quite rapid, often less than one minute. The duration of general anesthesia depends on the procedure and the type of anesthetic used. If gas anesthetic is used, the duration of anesthesia can be controlled by varying the concentration of the anesthetic administered to the patient. For example, spay surgery usually take less than one hour.

More complicated procedures take more time. Fracture repairs and total hip replacements can take several hours. After the procedure is finished, the gas anesthesia is discontinued and the patient begins breathing oxygen. Pets typically begin to regain consciousness within 10 to 30 minutes. The patient usually remains groggy for several hours.

Local anesthetic takes effect within seconds after administration and generally lasts 15 to 30 minutes.

How long does Anesthesia take to perform ?

1. Allows proper muscle relaxation for prolonged periods of time2. Facilitates complete control of the airway, breathing, and circulation3. Can be used in cases of sensitivity to local anesthetic agent4. Can be administered without moving the patient from the supine position

Advantages of Anesthesia

1. You could have a bad reaction to the medicine.

2. You could feel sick to your stomach after surgery.

3. Your temperature could go very high and you might die.

4. You could have long-lasting numbness, dolor, or loss of function of body parts after block types of anesthesia.

Disadvantages of Anesthesia Machines

1. Supply voltage: 220-240 vac ± 10% at 50hz, 10amp

2. Breathing system specifications: volume 5500 mlabsorbent 1.35 kg (400 ml) / canister

3. APL valve: approximately 0 to 70 cmh2o

4. Maximum vacuum: 457 mm hg with pipeline drive gas at 345 kpa

5. Having electro-magnetic compatibility

6. Having 2 vaporizer systems

7. Environmental temperature: 10 to 40 °C

8. Flow compensation range 200 ml/min to 15 L/min

9. Tidal volume: 0 to 9999 ml, 1 ml resolution

10. Flow compensation range 200 ml/min to 15 L/min

11. Patient airway pressure range -20 to +120 cmh2o +/-2 cmh2o

12. O2 range: 8 to 100%

Technical Specifications of Anesthesia