anesthesia working station and its care in Operation theatre setting

anesthesia working station and its care in Operation theatre setting

1. Anesthesia workstation and its care Prepared By: Yojana Ghimire OPERATION THERATER NURSE

2. Introduction The anesthesia machine is a device which delivers a precisely- known but variable gas mixture, including anesthesia and life sustaining gases.

3. BASIC FUNCTION To receive compressed gases from their supplies. To create a safe gas mixture of known composition and flow rate. To deliver a gas mixture to patient at a safe pressure .

4. Types of anesthesia machine Intermittent : Gas flows only during inspiration. Continuous : Gas flows both during inspiration and expiration.

5. PARTS OF THE ANESTHESIA MACHINE monitor etc O 2 vent Isoflourence circuit flowsensor Apl valve sodalime

6. Mode of ventilation Controlled Pressure control(PC) volume control (VC) Supported continuous positive airway pressure(CPAP) pressure support(PS) Combine SIMV (PC)+PS SIMV (VC)+PS

7. Vent circuit

8. The function of  breathing circuit  is to deliver oxygen and anesthetic gases, and eliminate carbon dioxide

9. care Ventilator circuits should not be changed routinely for infection control purposes. The maximum duration of time that circuits can be used safely. Ventilator circuit tubing is a potential source of nosocomial infection and should be replaced every 48 to 72 hours or within 7 days . Other equipments including the ventilator bag and tubing which connects it to the CO2 absorber, could also be contaminated.

10. This practice of routine changes should be abandoned only if additional studies demonstrate that prolonged use of the same breathing circuit is associated with low rates of  ventilator-associated pneumonia .

11. Apl valve

12. Introduction The adjustable pressure-limiting ( APL )  valve  is part of the anesthesia machine breathing circuit. The  APL  releases anesthetic gases into the scavenging system and is intended to provide pressure control in the breathing circuit during manual bag ventilation.

13. Function of APL valve It limits the maximum pressure during manual ventilation . It also exhausts excess gas into the scavenger system during manual and spontaneous ventilation. The APL valve is connected to the patient airway through the ventilator. It functions only when the ventilator is in Manual/Spontaneous Mode, safe state, or ventilator override condition .

14. Soda lime

15. Introduction Soda lime  is a mixture of NaOH & CaO chemicals, used in granular form in closed breathing environments, such as general anesthesia, re-breathers and recompression chambers, to remove carbon dioxide from breathing gases to prevent CO 2  retention and carbon dioxide poisoning.

16. When CO 2  reacts with   soda lime , heat and water are formed, and pH changes. The latter causes the indicator contained in  soda lime  to  change color  (typically from white to pink), indicating that the absorbent is near the point of exhaustion.

17. During respiration, in the pause between inspiration and  expiration  gaseous exchange occurs at the alveolar level within the lungs. If  soda lime  has exceeded its capacity to absorb carbon dioxide, and is still being used, these  expired  CO 2  gases will re-circulate to your patient through the anesthetic circuit.

18. care Soda lime must be exhausted faster before its colour changes completely every 14 hourly its should be changed if possible. soda lime should  be replaced out every two weeks, even if not used. If inhalation : Severe irritation or burns of respiratory system, pulmonary edema lung inflammation. If  ingestion : Is harmful and may be fatal severe burns to mouth, throat, and stomach, nausea, vomiting.

19. BAIN CIRCUITS

20. Introduction     Bain circuit   is an anesthesia delivery system that connects a patient's airway to the anesthesia machine. They consist of different components: Fresh gas flow, reservoir bag, breathing tubes, expiratory valve, and patient connection.

21. Bain circuits use a high fresh gas flow to deliver anesthetic gases to the patient's airway and to wash out the exhaled carbon dioxide. - An inner tube delivers fresh gases and an outer corrugated tube serves as the outlet for exhaled gases. A  Bain circuit  ensures that there is no re-breathing of the exhaled gases.

22. ETCO2

23. INTRODUCTION End - tidal carbon dioxide  (ETCO2) is the level of  carbon dioxide  that is released at the end of an exhaled breath. Normal value  is 35-45 mmHg End - tidal capnography  refers to the graphical measurement of the partial pressure of carbon dioxide (in mm Hg) during expiration

24. FUNCTION ETCO2   can be recommended as a noninvasive method for determination of metabolic acidosis and can be used to detect early metabolic acidosis in patients with spontaneous breathing and represents the partial pressure or maximal concentration of CO2 at the end of exhalation.

25. ETCO2 is the  amount of  carbon dioxide  ( CO2 ) in exhaled air, which assesses ventilation. So a high  ETCO2  is a good sign of good ventilation, while low  ETCO2  is bad sign that represents hypoventilation. The amount of carbon dioxide exhaled at the end of each breath ( EtCO2 ) is measured through a sensor located between the patient's airway and ventilator and is then numerically and graphically displayed as a waveform.

26. care It should be flushed with oxygen after every surgical procedures for at least 5 -10 mins . If any occlusion occurs in sample line it should be changed with new one.

27. ISOFLURANE Isoflurane is a general inhalation anesthetic drug used to induce and maintain general anesthesia.   It induces muscle relaxation and reduces pains sensitivity by altering tissue excitability.

28. Adaptor Mark line to fill iso

29. Oxygen sensor   Oxygen sensor , which measures the Air/ Oxygen   mix, a pressure  sensor  is used to measure pressure applied to the patient (inhalation) and in some Ventilators to measure pressure of the gases leading to an external humidifier. To control and monitor the oxygen level of a patient on a ventilator, sensors are used to measure oxygen both in the gas being given to the patent as well as the exhaled oxygen level - also referred to as end-tidal oxygen (ETO2

30. Ultrasonic Flow Sensor An ultrasonic flow sensor measures respiratory flow rate. The velocity and flow rate of gas through the patient circuit are determined by measuring the differential time of flight of ultrasonic pulses transmitted upstream and downstream in the airway flow path. Flow measurements are independent of gas concentration and yield precise values with all normal anesthetic gases .

31. Ventilator Control Panel The use of the ventilator is accomplished through the operator control panel, located on the front of the ventilator. The panel provides display windows and control buttons for selecting parameter settings, ventilation modes, and Ventilator Standby.

32. Selector/Confirmation Knob Rotating the selector/confirmation knob changes a parameter setting after the parameter has been selected by pressing the appropriate button. Rotating the knob clockwise increases the setting. Rotating the knob counterclockwise decreases the setting. Pressing the selector/confirmation knob confirms changes in mode or parameter settings and confirms the clears prompts.

33. Parameter Setting Buttons Parameter setting buttons are used with the alphanumeric display and selector/confirmation knob to change operating parameters for the ventilator. Pressing the button once sends the current setting to the alphanumeric display. Rotating the selector/confirmation knob changes the displayed setting. Ventilator Standby Button Pressing the [Standby] button and confirming the choice sets the ventilator to Ventilator Standby, which minimizes drive gas use and allows for inspection or repairs when a patient is not being ventilated.

34. PATIENT MANAGEMENT ECG Spo2 Etco2 Alarms limits Medications Ventilators observation and alarms limits Full assessment of patients suctioning (to prevent aspiration). eye care oral care