Medical Gases_O2_N2O_Compressed Air_Critical care

This presentation will be helpful for 2nd year critical care allied health Sciences.

1. MEDICAL GASES DR.R.Rao Prethendhira Singh SRDCH

2. DEFINITION Medical gases are gases used in medical procedures A medical gas is defined as one that is manufactured, packaged, and intended for administration to a patient in anesthesia , therapy, or diagnosis .

3. Medical gases are considered prescription drugs because their use as drugs is unsafe without the supervision of a licensed practitioner or by properly instructed emergency personnel ( Anesthesiologist ) . Indian Government in exercise of power under Section 5 & 7 of the said Act had proclaimed the rules namely Gas Cylinder Rules, 2004 (Drugs & Cosmetic act) to regulate filling, ownership,transport and import of such gases .

4. PURPOSE OF MEDICAL GAS Medical gases are used within hospital settings for many purposes. Oxygen, used to provide supplemental oxygen to the  respiratory system  ; in dentistry in combination with  nitrous oxide  ; and as an emergency standby.

5. WHERE MEDICAL GAS IS USED The departments that use medical gases in hospitals include Operating rooms, Pre-communicators, Recovery rooms, Debridement rooms, Obstetrics and gynecology wards, ICU wards, and general wards.

6. POINTS TO CONSIDER Medical gas systems are commonly  color coded  to identify their contents. Emergency shut-off valves, or zone valves, are often installed in order to stop gas flowing to an area in the event of fire or substantial leak, as well as for service.

7. COLOUR CODED

8. EQUIPMENTS USED Cylinder, Medical gas regulator , Medical gas pipeline system (MPGS) , Cylinder manifold , Oxygen therapy equipment There are 7 kinds of gases commonly used: oxygen , nitrogen , nitrous oxide , argon , helium , carbon dioxide and compressed air (medical air) & medical vaccum .

9. Portable Size Medical Oxygen Regulator | Piston Type Oxygen Flowmeter

10. SAFETY NORMS AND GUIDELINES – MEDICAL GAS PIPELINE SYSTEMS

11. A CPAP machine includes: A mask that fits over just your nose or both your nose and mouth. Straps to position the mask on your face. A tube that connects the mask to the machine’s motor . A motor that blows air into the tube. An air filter that purifies the air entering your nose or mouth. Some CPAP machines have other features as well, like heated humidifiers and adjustable pressure settings .

12. CPAP machine is just one type of PAP (positive airway pressure) device. CPAP is the most common among these machines. Other types include: Auto CPAP : This device self-regulates, using a range of pressures to keep your airways open. Bi-level PAP : This machine uses two different pressures — a higher pressure while breathing in (inhalation) and a lower one while breathing out (exhalation). Auto-bilevel PAP : This machine self-regulates the inhalation and exhalation pressures Adaptive servo-ventilation (ASV) : ASV is for people with certain types of central sleep apnea . ASV monitors your breathing and adjusts the pressures to make your breathing more stable. It may also deliver a breath when necessary.

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14. Oxygen therapy Definition: Oxygen is a colorless, odorless, tasteless gas that is essential for the body to function properly and to survive.

15. What is meaning of O2 therapy Oxygen therapy is the administration of oxygen at a concentration of pressure greater than that found in the environmental atmosphere The air that we breathe contain approximately 21% oxygen the heart relies on oxygen to pump blood.

16. Purpose Oxygen therapy is a key treatment in respiratory care. The purpose is to increase oxygen saturation in tissues where the saturation levels are too low due to illness or injury.

17. oxygen therapy is used to treat Example in case :- Documented hypoxemia Severe respiratory distress (acute asthma or pneumonia) Severe trauma Chronic obstructive pulmonary disease (COPD, including chronic bronchitis, emphysema, and chronic asthma)

18. oxygen therapy is used to treat Pulmonary hypertension Acute myocardial infarction (heart attack) Short-term therapy, such as post-anesthesia recovery Oxygen may also be used to treat chronic lung disease patients during exercise .

19. Preparation A physician's order is required for oxygen therapy , except in emergency use. Clinical observations. indicated in Arterial Blood Gas measurements ,(ABGs ) . Pulse Oximetry.

20. Pulse oximetry

21. Cautions For Oxygen Therapy Oxygen toxicity – can occur with FIO2 > 50% longer than 48 hrs Danger of fire Infection

22. Classification of Oxygen Delivery Systems Low flow systems contribute partially to inspired gas client breathes Ex: nasal cannula, simple mask , non-re breather mask , Partial rebreather mask High flow systems deliver specific and constant percent of oxygen independent of client’s breathing Ex: Venturi mask,, trach collar, T-piece

23. Methods of oxygen administration: 1- Nasal cannula

24. Nasal cannula It is a disposable. plastic devise with two protruding prongs for insertion into the nostrils, connected to an oxygen source. Used for low-medium concentrations of Oxygen (24-44%).

25. Disadvantages Advantages Priority Nursing Interventions Amount Delivered F1o2 (Fraction Inspired Oxygen) Method may cause irritation to the nasal and pharyngeal mucosa if oxygen flow rates are above 6 liters/minute Variable FIO2 Client able to talk and eat with oxygen in place Easily used in home setting Check frequently that both prongs are in clients nares Never deliver more than 2-3 L\min to client with chronic lung disease Low flow 24-44 % 1 L\min=24% 2 L\min=28% 3 L\min=32% 4 L\min=36% 5 L\min=40% 6 L\min=44% Nasal Cannula

26. Face mask The simple Oxygen mask The partial rebreather mask: The non rebreather mask: The venturi mask:

27. The simple Oxygen mask Simple mask is made of clear, flexible , plastic or rubber that can be molded to fit the face.

28. The simple Oxygen mask It delivers 35% to 60% oxygen . A flow rate of 6 to 10 liters per minute. Often it is used when an increased delivery of oxygen is needed for short periods (i.e., less than 12 hours ).

29. Disadvantages Advantages Priority Nursing Interventions Amount Delivered F1o2 (Fraction Inspired Oxygen) Method Tight seal required to deliver higher concentration Difficult to keep mask in position over nose and mouth Potential for skin breakdown (pressure, moisture) Wasting Uncomfortable for pt while eating or talking Expensive with nasal tube Can provide increased delivery of oxygen for short period of time Monitor client frequently to check placement of the mask. Support client if claustrophobia is concern Secure physician's order to replace mask with nasal cannula during meal time Low Flow 6-10 L\min 35%-60% Simple mask

30. The partial rebreather mask: The mask is have with a reservoir bag must romaine inflated during both inspiration & expiration It collection of the first parts of the patients' exhaled air. It is used to deliver oxygen concentrations up to 80%.

31. The partial rebreather mask The oxygen flow rate must be maintained at a minimum of 6 L/min to ensure that the patient does not rebreathe large amounts of exhaled air. The remaining exhaled air exits through vents.

32. The non rebreather mask This mask provides the highest concentration of oxygen (95-100%) at a flow rate6-15 L/min. It is similar to the partial rebreather mask except two one-way valves prevent conservation of exhaled air. The bag is an oxygen reservoir

33. Disadvantages Advantages Priority Nursing Interventions Amount Delivered F1o2 (Fraction Inspired Oxygen) Method Requires tight seal (eating and talking difficult, uncomfortable Not as drying to mucous membranes PT can inhale room air through openings in mask if oxygens supply is briefly interrupted Set flow rate so mask remains tow-thirds full during inspiration Keep reservoir bag free of twists or kinks Low Flow 6 L\min 75%-80% oxygen Partial Rebreather Mask

34. Disadvantages Advantages Priority Nursing Interventions Amount Delivered F1o2 Method Impractical for long term Therapy Malfunction can cause CO2 buildup suffocation Expensive Feeling of suffocation Uncomfortable Costly Delivers the highest possible oxygen concentration Suitable for pt breathing spontaneous with sever hypoxemia Maintain flow rate so reservoir bag collapses only slightly during inspiration Check that valves and rubber flaps are function properly (open during expiration ) Monitor SaO2 with pulse oximeter Low Flow 6-15 L \min 80%-100% Non rebreather MASK

35. Venturi mask It is high flow concentration of oxygen . Oxygen from 40 - 50% At liters flow of 4 to 15 L/min.

36. Disadvantages Advantages Priority Nursing Interventions Amount Delivered F1o2 Method uncomfortable Risk for skin irritation produce respiratory depression in COPD patient with high oxygen concentration 50% Delivers most precise oxygen concentration Doesn’t dry mucous membranes (humidity Requires careful mointoring to verify F1O2 at flow rate ordered Check that air intake valves are not blocked Oxygen from 40-- 50% of 4 to 15 L/min. Venturi Mask

37. T-piece Used on end of ET tube when weaning from ventilator Provides accurate FIO2 Provides good humidity

38. Side effect & complication of oxygen therapy Oxygen toxicity Retrolental fibroplasia Absorption atelectasis

39. oxygen toxicity It is a condition in which ventilator failure occurs due to inspiration of a high concentration of oxygen for aprolonged period of time. Oxygen concentration greater than 50% over 24 to 48 hours can cause pathological changes in the lungs .

40. Signs and symptoms of oxygen toxicity: • Non-productive cough. • Nausea and vomiting. • Substernal chest pain. • Fatigue. • Nasal stuffiness. • Headache. • Sore throat. • Hypoventilation. . Nasal congestion. . Dyspnea. . Inspiration pain.

41. Evaluation: Breathing pattern regular and at normal rate. pink color in nail beds, lips, conjunctiva of eyes. No confusion, disorientation, difficulty with cognition. Arterial oxygen concentration or hemoglobin Oxygen saturation within normal limits .

42. Documentation: Date and time oxygen started. Method of delivery. Oxygen concentration and flow rate. Patient observation. Add oronasal care to the nursing care plan

43. O2 DELIVERY DEVICES EQUIPMENT FLOW FIO2 SPECIAL NOTES NASAL CANNULA 1/2 - 6 L/M .24 – 44 6 L/M MAX. SIMPLE O2 MASK 6 - 10 L/M .35 – 55 USE 5 L/M (WITHOUT BAG) MINIMUM RESERVOIR MASK 10-15 L/M .60 -80 PAGE RT IF USED (MASK WITH BAG) (BAG TO NOT COLLAPSE) VENTI MASK 3 L/M .24, 26, 31, READ ENCLOSED 6 L/M .35, .40, .50 INSTRUCTIONS NEBULIZER 8 L/M OR > .28, .30, .35 MIST MUST BE .40, .50, 70 VISIBLE *** SHOWS THAT FIO2 VARIES WITH DIFFERENT F, VT, INSPIRATORY FLOW RATES.

44. General Anesthesia -Procedures Preoperative assessment Medical H/O, health status, Consent form, Explain anesthetic and analgesic (ASA-I-IV). During Operation (ECG, Pulse oximeter, Defibrillator etc.) Anesthetic room/ Op.Theater, Draping, CRASH CART IV (Thio/Pro) Followed by Inhalational GA (Mask , Endotracheal tube –Snorkel which allows Pt breathing and protect airway) Post Op./Recovery Stop anesthesia - Pt will be taken to recovery room –Shifted to ward It may affect memory, concentration and reflexes hence bystander for 24 hrs Side effects – Feeling sick, cold, shivering, confusion, memory loss, bladder problem, dizziness, sorethroat

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46. Definition (Five Primary effects - Reversible) Amnesia – Memory loss Analgesia - Loss of all sensations Sleep- Unconsciousness Immobility Skeletal Muscle relaxation Abolition of Somatic and Autonomic reflexes Differences B/w LA & GA

47. Techniques (Monitoring & Emergency equipment) Open drop Method Anesthetic machines (Cylinder, flow meter, vapourisers , valves, rubber tubing bag) - Open & Closed system.

48. Inhalational agents Classification A. Volatile anaesthetics B. Anaesthetic gases Diethyl Ether (CH 3 CH 2 -OCH 2 CH 3 ) Divinyl Ether [(C 2 H 3 ) 2 O] Ethyl chloride (C 2 H 5 Cl) Chloroform (CHCl 3 ) Trichloroethylene (CCl 2 CHCl) Halothane (CF 3 CHClBr) Methoxyflurane Enflurane Isoflurane Desflurane Sevoflurane Nitroux oxide Cyclopropane Ethylene Xenon, Argon Sulphur hexafluoride

49. Classification Inhalational Gas Liquids Nitrous oxide Halothane Enflurane Isoflurane Desflurane Sevoflurane

50. Intravenous Inducing Agents Slower acting Thiopentone sodium Benzodiazipines Methohexitone Diazepam Propofol Lorazepam Etomidate Midazolam Dissociative Ketamine Neurolept analgesia

51. Anesthetic Protocol Premedication Induction (Thiopentone / Propofol) Maintenance of Anesthesia (N2o + Halothane) Basis – MAC of Halothane conc.required is reduced due to 2 nd gas effect 2 nd Gas Effect – N20 Diffuses rapidly & Halothane diffuses poorly, when combined halothane also diffuses rapidly. Dose is reduced so recovery wiil be faster Halothane – Potent anesthetic & Poor analgesic – N20 Viceversa. Skeletal Muscle relaxation Analgesia – (Pre, during & Post) Other drugs- to reverse NM blockade, to prevent vomiting and to reverse residual effects of Opioid and BZDs

52. Stages 1. Stage of analgesia but there is no Amnesia 2. Stage of excitement and delirium (Dangerous) 3. Surgical anesthesia Plane 1- Roving of eye balls (Skeletal Muscle tone and respiration are normal) Plane 2- Loss of light, corneal and laryngeal reflex SURGICAL PROCEDURES ARE CARRIED OUT. Plane 3- Dilated Pupil and absence of Plane 2 reflex Plane 4- Complete muscle relaxation, Dilated pupil, loss of reflex –respiration is abdominal 4. Medullary paralysis – Usually fatal due to Overdose

53. NITROUS OXIDE Physical properties: It is a laughing gas. It is only inorganic anesthetic gas in clinical use. Colorless and odorless Non Explosive and Non Infammable Gas at room temperature and can be kept as a liquid under pressure. It is relatively inexpensive.

54. Nitrous oxide (N 2 O) (Laughing gas) 70% N2O + 28% O2 + 2-3% of Halothane Used as an adjuvant for the second gas effect. Few undesirable side effects:- Risk of Abuse in anesthetists, dentists, nurses. More than 4 hours- ? Diffusion hypoxia, second gas effect

55. MECH. OF ACTION MAC – Minimum Alveolar conc. Is min. conc. Of anesthetic in alveoli to produce immobility in response to an incision in 50% of Patients. Main site of action is in reticular formation which maintains state of consciousness. Based on Dissolving capacity in membrane lipids at synapses. Interacts with protein or lipid protein interface Potentiate GABA A Receptor & Glycine, K+ Channels (inhibitory neuro transmitters) Inhibits NMDA- Glutamate (Excitatory), AMPA, 5HT3 Inhibits Nicotinic cation channels Second gas effect & Diffusion hypoxia Elimination

56. Pharmacokinetics Inhalational (Gas/ Vapour ) diffuses rapidly into pulmonary alveoli and tissue barriers MAC is an index of potency and its partial pressure Alveoli Blood Brain FACTORS AFFECTING PP of Anesthetic Pulmonary Ventilation Alveolar exchange Solubility of GA in Blood & tissues Cerebral Blood flow Eliminated through Pulm.Epithelium

57. Diffusion Hypoxia -when admin. of N20 is discontinued it rapidly diffuses from blood to alveoli, hence PaO2 is reduced resulting in Hypoxia. (prevented by giving 100% O2)

58. Effects of Nitrous Oxide on Organ System 1. CARDIOVASCULAR SYSTEM Stimulate sympathetic nervous system. Directly depresses myocardial contractility. Arterial blood pressure ,heart rate and cardiac output are slightly increased. 2. RESPIRATORY SYSTEM: Increases respiratory rate with decreases tidal volume. Minimal change in minute ventilation.

59. 3. CEREBRAL: Increases CBF thus increasing intracranial pressure. 4. RENAL SYSTEM: It decreases renal blood flow thus leads to drop in glomerular filtration rate and urinary output. 5. HEPATIC SYSTEM: Decreases the Hepatic blood flow but to a lesser extent than other inhalation agents. 6. GASTROINTESTINAL: It causes post operative Nausea and Vomiting.

60. CONTRAINDICATION OF N2O Air embolism Pneumothorax Acute Intestinal Obstruction Tension Pneumocephalus Tympanic membrane grafting

61. Uses of N2O Mixed with oxygen at 40-67%, then delivered to patient Reduces MAC 20-30% Used with Halothane and Methoxyflurane to reduce the adverse effects of these gases

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63. Medical Air/ Compressed Air Composition : Medical air - 78% nitrogen and 21% oxygen (atmospheric air Purity Standards : Medical air is free from particles, oil, and other impurities that could potentially harm patients.(.) it is specially purified to remove contaminants and moisture. Applications : Medical air is used for various medical applications, including: Respiratory Support : It can be used in ventilators and respiratory therapy equipment to help patients breathe. Anesthesia : Medical air is often mixed with medical gases like oxygen and nitrous oxide to administer anesthesia to patients during surgery. Surgical Tools : It powers pneumatic surgical instruments used in procedures such as orthopedic surgeries.

64. Delivery and Monitoring : Delivered through a dedicated pipeline system (MPLGS) within healthcare facilities. The delivery system includes filters and sterilizatio n units to maintain the air's purity. Regular monitoring of the air quality and system maintenance are essential to ensure it remains safe for patient use. Safety Considerations : Due to its critical role in patient care, medical air systems are designed with safety features to prevent contamination or malfunction. Staff are trained to handle and monitor the system to ensure patient safety.

65. Compressed Air Generation : Medical air is produced by compressors designed specifically for medical use . These compressors ensure that the air meets specific purity standards, typically outlined by Indian pharmacopeias.

66. 2.Air Filtration and Purification : Medical air must be clean and free from contaminants such as particles, oil, and microorganisms. System includes Filter Sterilization units to ensure the air meets medical standards .

67. 3.Distribution System : Once compressed and purified, the medical air is distributed Through a network of pipelines or hoses to various points of use within a healthcare facility. These points might include Patient rooms, Operation theaters, Intensive care units, Other areas where medical procedures are performed.

68. Application : Medical air is used for various purposes: Ventilation Support : In respiratory therapies and anesthesia delivery systems. Surgical Tools : To power pneumatic surgical instruments like drills and saws. Environmental Control : Maintaining a controlled environment in critical care areas.

69. Monitoring and Maintenance : Regular monitoring of air quality and system maintenance are crucial to ensure the continued delivery of clean, reliable medical air. Safety Considerations : Systems are designed with safety features to prevent contamination or malfunction, as medical air is critical for patient care and safety. Overall, the medical air driving system plays a vital role in supporting medical procedures and ensuring patient safety in healthcare settings.

70. CARBON DIOXIDE Medically, carbon dioxide is used to inflate the abdominal cavity and colon for laparoscopy and colonoscopy. In addition, it is also used for laboratory culture of bacteria (anaerobic bacteria).

71. Carbon dioxide can be made into dry ice by applying pressure (5.2 atmospheres) and cooling (-56.6°C below). Medical dry ice is used for cryotherapy to treat cataracts and vascular diseases.

72. Typically used for  insufflation  during surgery, and also used in laser surgeries. System pressures are maintained at about 345  kPa (50.0 psi), UK 4 bar (400  kPa ; 58 psi). It is also used for certain respiratory disorders. It contains 5 percent.

73. ARGON, HELIUM They are colorless , odorless , non-toxic inert gas. Medically used for argon gas knife, gas knife, and other surgical instruments.

74. NITROGEN Nitrogen is a colorless , odorless , non-toxic, non-flammable gas. It is inactive at room temperature and does not react chemically with ordinary metals.

75. Nitrogen is used to drive medical equipment and tools. Liquid nitrogen is commonly used in cryosurgery in surgery, stomatology , gynecology , and ophthalmology.

76. Nitrogen is typically used to power  pneumatic  surgical equipment during various procedures, and is supplied by high-pressure cylinders. Pressures range around 1.2  MPa (170 psi) to various locations.

77. MEDICAL VACUUM Medical vacuum in a hospital supports  suction  equipment and evacuation procedures, supplied by vacuum pump systems exhausting to the atmosphere.

78. Vacuum will fluctuate across the pipeline, but is generally maintained around −75  kPa (−560 mmHg; −22  inHg ), −450 mmHg (−60  kPa ; −18  inHg ) UK.

79. WASTE ANAESTHETIC GAS DISPOSAL/ANAESTHETIC GAS SCAVENGING SYSTEM Waste anaesthetic gas disposal, or anaesthetic gas scavenging system, is used in hospital  anaesthesia evacuation procedures .

80. MEDICAL GAS MIXTURES There are many gas mixtures used for clinical and medical applications. They are used for patient diagnostics such as lung function testing or blood gas analysis.

81. Test gases are also used to calibrate and maintain medical devices used for the delivery of anaesthetic gases. In laboratories, culture growth applications include controlled aerobic or anaerobic incubator atmospheres for biological cell culture or tissue growth.

82. Controlled aerobic conditions are created using mixtures rich in oxygen and anaerobic conditions are created using mixtures rich in hydrogen or carbon dioxide. Supply pressure is 4 bar (400  kPa ; 58 psi). Two common medical gas mixtures are  entonox  and  heliox .

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