SESSION 3 OXYGEN THERAPY

Transcription

1 SESSION 3 OXYGEN THERAPY Harith Eranga Yapa Department of Nursing Faculty of Health Sciences The Open University of Sri Lanka 1

2 Outline Methods of delivery Complications of oxygen therapy Artificial airways Intubation and extubation Mechanical ventilation Nursing management 2

3 Methods of Delivery Can be administered by many different devices. Common problems associated with these devices include system leak and obstructions, device displacement and skin irritation. These devices are categorized as low flow, reservoir and high flow systems. 3

4 Low Flow Systems Delivers supplemental oxygen directly into the patient s airway at a flow rate of 8L/min or fewer. This oxygen flow is insufficient to meet the patient s inspiratory requirements and results a variable fraction of inspired oxygen as supplemental oxygen is mixed with room air. 4

5 Reservoir System Designed to accumulate and store oxygen between breaths. Patient can draw oxygen from the reservoir even his/ her inspiratory flow exceeds the oxygen flow of the oxygen delivery system, to meet the patient s inspiratory requirements. When compared to low flow system, mixing of oxygen with room air is minimal. 5

6 High Flow Systems Delivers oxygen to patient s airway in an amount sufficient to meet patient s inspiratory volume requirements. High flow nasal cannula, a type of high flow system delivers warmed, humidified oxygen to the patient using a blending system. 6

7 High Flow Systems This system provides more comfort and better tolerance to patients as it reduces the work of breathing especially in acute lung failure. 7

8 Complications of Oxygen Therapy Oxygen toxicity Can occur in patients who inhale oxygen concentrations of greater than fifty percent for more than 24 hours. Patients who require intubation, mechanical ventilation, and high oxygen concentrations for longer periods are at risk of developing oxygen toxicity. 8

9 Complications of Oxygen Therapy Oxygen toxicity-clinical features substernal chest pain that is aggravated by deep breathing, dry cough tracheal irritation In addition, nasal stuffiness, sore throat, eye and ear discomfort may occur. 9

10 Complications of Oxygen Therapy Oxygen toxicity However, chest radiographs and pulmonary function tests will not show any changes until the clinical features become severe. Once the normal oxygen concentration is established, these clinical features may reverse rapidly. 10

11 Complications of Oxygen Therapy Carbon dioxide retention Can occur due to administration of high concentrations of oxygen. Mainly occurring in patients with Chronic Obstructive Pulmonary Diseases (COPD). In COPD, normal stimulus to breathe (increasing CO 2 levels) is muted and that decrease the levels of oxygen in the lungs. 11

12 Complications of Oxygen Therapy Carbon dioxide retention If hypoxemia is corrected by the administration of oxygen, the stimulus to breathe is diminished by developing hypoventilation. As a result of that carbon dioxide levels will increase further. 12

13 Nursing Management of patient receiving oxygen therapy Clear oral, nasal and tracheal secretions as necessary. Maintain the patency of airway. Setup the oxygen equipment and administer through heated and humidified system. Monitor the oxygen litre flow. Monitor position of the oxygen delivery device. 13

14 Nursing Management of patient receiving oxygen therapy Frequently check oxygen delivery device to ensure that the prescribed oxygen concentration is being delivered. Monitor the effectiveness of oxygen therapy by using Arterial Blood Gas (ABG) analysis and pulse oximetry. Monitor patient s ability to tolerate removal of oxygen while eating. 14

15 Nursing Management of patient receiving oxygen therapy Change oxygen delivery device from mask to nasal prongs during meals as tolerated. Monitor the signs of oxygen toxicity. Monitor patient s anxiety related to need for oxygen therapy. Monitor for skin breakdown from friction of oxygen delivery device. 15

16 Artificial Airways-Pharyngeal Airways Used to maintain patency of patient s airway by keeping tongue away from obstructing the upper airway. Two types of pharyngeal airways include oropharyngeal and nasopharyngeal airways. 16

17 Artificial Airways-Pharyngeal Airways Incorrect insertion may cause trauma to the oral and nasal cavity, gagging, obstruction of airway due to usage of large airways, laryngospasm and vomiting. 17

18 Oropharyngeal airways Curved, firm, hollow plastic tubes with a rectangular opening. Available in various sizes. Proper size is determined by holding the airway against the side of patient s face and ensuring that it extends from corner of the mouth to the angle of the jaw. 18

19 Oropharyngeal airways Improperly sized oropharyngeal airways cause obstruction of airway. When the airway is properly placed, the tip of the airway lies above the epiglottis at the base of the tongue. Should be used only in unconscious patients who has absent or diminish gag reflex. Otherwise patients are more prone to vomit as airway insertion induce gag reflex. 19

20 Oropharyngeal airways 20

21 Nasopharyngeal airways Soft rubber hollow tubes which are available in various sizes. Appropriate size is determined by holding the airway against the side of patient s face and ensuring that it extends from the tip of the nose to the ear lobe. When the airway is properly placed, the tip of the airway lies above the epiglottis at the base of the tongue. 21

22 Nasopharyngeal airways 22

23 Endotracheal tubes (ETT) Plastic flexible tubes which are available in various sizes. Commonly used for providing short term airway management. On one end of the tube has a cuff that is inflated with the use of pilot balloon while other end of the tube is a 15mm adaptor that facilitates connection to a manual resuscitation bag, T tube or ventilator. 23

24 Endotracheal tubes (ETT) Mainly indicated for maintenance of airway patency, protection of airway from aspiration, application of positive pressure ventilation and use of high oxygen concentrations. Can be inserted through orotracheal or nasotracheal route. 24

25 Endotracheal tubes (ETT) Orotracheal route is preferred in emergency situations as it is easier to insert. However, nasotracheal route provide greater comfort to the patient over time and used in patients with jaw fracture. 25

26 Endotracheal tubes (ETT) 26

27 ETT Intubation Rapid sequence intubation (RSI) is a process which is often used to intubate critically ill patients. RSI is considered safer for patients as it reduce the risk of aspiration. 27

28 Step 1- Preparation The first step of RSI is gathering and organizing required equipment for ETT intubation. It include a suction system with catheters, manual resuscitation bag with a mask connected to 100% oxygen, a laryngoscope with assorted blades, various sizes of ETTs, and a stylet. 28

29 Step 1- Preparation All equipment should be in working order. In addition, patient should be prepared for the procedure by inserting an intravenous access and attaching to a pulse oximetry. 29

30 Step 2- Preoxygenation In the second step, 100% oxygen should be administered for 3-5 minutes via a tight fitting face mask. If the patient is unable to maintain adequate spontaneous ventilations, then assisted ventilations are initiated with a manual resuscitation bag. 30

31 Step 3- Pretreatment While the patient is being preoxygenated, patient should be pretreated with adjunct medications to get rid physiologic responses to intubation. Atropine, lidocaine and fentanyl are commonly used medications in this step. If possible, pretreatment should be administered 3 minutes before the next step 31

32 Step 4- Paralysis with Induction In this step, paralytic agent and sedative agent are administered to achieve induction and paralysis. Sedative agents, such as midazolam, ketamine, etomidate and propofol are used to facilitate rapid loss of consciousness. To achieve muscle paralysis, succinylcholine and rocuronium are commonly used. 32

33 Step 5- Protection and Positioning The patient should be positioned with neck flexed and head slightly extended in the sniff position. Dental devices should be removed if present. The oral cavity and pharynx should be suctioned. After that cricoids pressure should be applied to protect the airway by preventing vomiting and aspiration. 33

34 Step 6- Placement of ETT Next, ETT is inserted into the trachea and placement is confirmed. Then patient is assessed for bilateral breath sounds and chest movements. Absence of breath sounds indicate esophageal intubation whereas breath sounds heard over one side indicate main stem intubation. 34

35 Step 6- Placement of ETT Once the tube placement is verified, cuff of tube is inflated to secure the placement. Finally chest radiograph is taken to confirm the tube placement. 35

36 Step 7- Post intubation management Finally, ETT is secured to patient s face by pasting a plaster tape. Thus, it prevents tube movement and potential dislodgement. 36

37 Complications associated with ETT intubation Nasal and oral trauma Pharyngeal trauma Vomiting Aspiration Tracheal rupture (rare) Hypoxemia and hypercapnia 37

38 Complications associated with ETT intubation In addition, nasal and oral inflammation and ulceration, laryngeal and tracheal injuries, sinusitis, otitis, tube obstruction can occur due to ETT in place. Some complications can occur days to weeks after removing the ETT. These include; laryngeal and tracheal stenosis and cricoid abscess. 38

39 Tracheostomy tubes Is the preferred way of managing airway when long term intubation is required. Indicated in conditions such as upper airway obstruction due to trauma, tumors or swelling and need to facilitate airway clearance due to spinal cord injury. Made up of plastic or metal and may have single or double lumens. 39

40 Tracheostomy tubes Single lumen tracheostomy tubes contain a cuff which is connected to a pilot balloon and an obturator, which is used during tube insertion. Double lumen tracheostomy tubes consist of cuff, obturator and an inner cannula, that can be removed and reinserted when do cleaning. 40

41 Tracheostomy tubes 41

42 Tracheostomy tubes Provide the best route of long term airway management as it avoid oral, nasal, pharyngeal and laryngeal complications linked with ETT. The tube is shorter, wider in diameter and less curved than ETT thus, resistance to air flow is minimal and make breathing easier. 42

43 Tracheostomy tubes Other advantages of tracheostomy tube include easier suctioning, greater comfort to the patient, capability of patient to eat or talk if possible and easier ventilator weaning. 43

44 Complications associated with Tracheostomy tube Misplacement of the tracheostomy tube Haemorrhage Laryngeal nerve injury 44

45 Complications associated with Tracheostomy tube In addition, stomal infection, tracheoesophageal fistula, haemorrhage, tube obstruction and displacement can occur due to tracheostomy tube in place. Some complications can occur days to weeks after removing the tracheostomy tube. These include; tracheal stenosis and tracheocutaneous fistula. 45

46 Nursing Management of patient with an artificial airway Nursing interventions include providing humidification, managing the cuff, suctioning, establishing method of communication and providing oral care. 46

47 Humidification In normal circumstances, humidification is carried out by mucosal layer of the upper respiratory tract. However, external means of humidification is required when this area has bypassed as occurs with ETT and tracheostomy tubes or when supplemental oxygen is used. 47

48 Humidification Various humidification devices add water to inhaled gas to prevent drying and irritation of respiratory tract, to prevent undue loss of body water, and to facilitate secretion removal. The humidification should provide inspired gas conditioned (heated) to body temperature and saturated with water vapor. 48

49 Cuff Management Generally low pressures, high volume cuffed tubes are used in order to prevent complications. Proper cuff inflation techniques and cuff pressure monitoring are crucial when caring with a patient with artificial airway. 49

50 Suctioning Suctioning is a sterile procedure and often essential to maintain the patency of airway in patients with an ETT or tracheostomy tube. 50

51 Suctioning Indications for suctioning include coughing, secretions in the airway, respiratory distress, presence of rhonchi on auscultation, increased peak airway pressures on the ventilator, and decreasing oxygenation saturation. 51

52 Suctioning Complications associated with suctioning include, hypoxemia, atelectasis, bronchospasms, dysrhythmias, increased intracranial pressure and airway trauma. 52

53 Endotracheal Extubation Extubation is the process of removing ETT. Before the cuff of an ETT is deflated, in preparation for removal, it is essential to remove secretions which may present above the tube cuff. Complications of extubation include; sore throat, stridor, hoarseness, vocal cord immobility, pulmonary aspiration and cough. 53

54 Nursing interventions associated with the removal of ETT Elevate the head of bed to 75 degrees. Instruct patient about the procedure. Hyperoxygenate patient and suction endotracheal airway. Deflate endotracheal cuff and remove ETT. Encourage patient to cough and expectorate sputum. 54

55 Nursing interventions associated with the removal of ETT Administer oxygen as ordered. Encourage coughing and deep breathing. Suction airway if necessary. Monitor for respiratory distress. Monitor vital signs. Encourage voice rest for 4-8 hours as appropriate. Monitor ability to swallow and talk. 55

56 Invasive Mechanical Ventilation 56

57 Mechanical Ventilation Is the process of using an apparatus to facilitate respiration for the purpose of enhancing pulmonary gas exchange. 57

58 Mechanical Ventilation- Indications reversing hypoxemia, acute respiratory acidosis, relieving respiratory distress, preventing atelectasis and respiratory muscle fatigue, permitting sedation, decreasing oxygen consumption and stabilizing the chest wall. 58

59 Types of Ventilators There are two types of ventilators. Positive pressure ventilators and negative pressure ventilators. Negative pressure ventilators are applied externally to patients and diminish the atmospheric pressure surrounding the thorax to initiate inspiration. 59

60 Types of Ventilators Positive pressure ventilators use a mechanical drive to mechanism to force air into patient s lungs through ETT or tracheostomy tube. 60

61 Ventilator Mechanics In order to ventilate the patient properly, there are four phases of ventilations such as; trigger, limit, cycle and baseline to complete by the ventilator. 1.Change from exhalation to inspiration 2.Inspiration 3.Change from inspiration to exhalation 4.Exhalation 61

62 Ventilator Mechanics The ventilator uses four different variables such as; volume, pressure flow and time to begin, sustain, and terminate each of these phases. 62

63 Trigger Initiate the change from exhalation to inspiration Breaths may be pressure triggered or flow triggered depending on sensitivity setting of ventilator and patient s inspiratory effort; or time triggered, depending on the rate setting of the ventilator. Limit Maintain the inspiration - Breaths can be pressure limited, flow limited or volume limited. 63

64 Limit Maintain the inspiration Breaths can be pressure limited, flow limited or volume limited. Only sustain inspiration and not end it. 64

65 Cycle End the inspiration Breaths can be pressure cycled, flow cycled or volume cycled and time cycled. 65

66 Baseline Variable that controlled during exhalation. Pressure is almost always used to adjust this variable. 66

67 Modes of Ventilation Continuous Mandatory Ventilation (CMV) Delivers gas at preset tidal volume or pressure (depending on selected cycling variable) in response to patient s efforts and initiate breath if patient fail to do so within preset time. 67

68 Modes of Ventilation Continuous Mandatory Ventilation (CMV) Volume controlled CMV is used as primary mode of ventilation in spontaneously breathing patients with weak respiratory muscles. Pressure controlled CMV is used in patients with decreased lung compliance or increased airway resistance. 68

69 Modes of Ventilation Synchronous Intermittent Mandatory Ventilation (SIMV)/ IMV Delivers gas at preset tidal volume or pressure (depending on selected cycling variable) and rate while allowing patient to breathe spontaneously. Ventilator breaths are synchronized to patient s respiratory effort. 69

70 Modes of Ventilation Synchronous Intermittent Mandatory Ventilation (SIMV)/ IMV Volume controlled SIMV is used as a primary mode of ventilation in many clinical situations and as a weaning mode. 70

71 Modes of Ventilation Synchronous Intermittent Mandatory Ventilation (SIMV)/ IMV Pressure controlled SIMV is used in patients with decreased lung compliance or increased airway resistance when the need to preserve the patient s spontaneous effects is important. 71

72 Modes of Ventilation Continuous Positive Airway Pressure (CPAP) Positive pressure applied during spontaneous breaths; patient controls rate, inspiratory flow and tidal volume. 72

73 Modes of Ventilation Continuous Positive Airway Pressure (CPAP) Is a spontaneous breathing mode used in patients to increase functional residual capacity and improve oxygenation by opening collapsed alveoli at end expiration. It is also used for weaning. 73

74 Modes of Ventilation Pressure Support Ventilation (PSV) Preset positive pressure used to augment patent s inspiratory efforts. Patent controls rate, inspiratory flow and tidal volume. PSV is a spontaneous breathing mode used as the primary mode of ventilation in patients with stable respiratory drive. 74

75 Ventilator Settings Parameter Description Typical Settings Respiratory Rate Number of breaths the ventilator delivers per minute 6-20 breaths/min Tidal Volume (Vt) Volume of gas delivered to patient during each ventilator breath 6-10ml/Kg 75

76 Ventilator Settings Parameter Description Typical Settings Oxygen Concentration (Fio 2 ) Positive End Expiratory Pressure (PEEP) Fraction of inspired oxygen delivered to patient Positive pressure applied at the end of expiration of ventilator breaths May be set between 21% and 100%; adjusted to maintain PaO2 (arterial partial pressure of oxygen) level greater than 60mmHg or Spo 2 (oxygen saturation based on pulse oximeter) level greater than 92% 3-5cmH 2 O 76

77 Ventilator Settings Parameter Description Typical Settings Pressure Support (PS) Inspiratory flow rate and time I:E ratio Positive pressure used to augment patient s inspiratory efforts Speed with which the tidal volume is delivered Ratio of duration of inspiration to duration of expiration 5-10 cmh 2 O 40-80L/min Time: sec. 1:2 to 1:1.5 77

78 Ventilator Settings Parameter Description Typical Settings Sensitivity Determines the amount of effort the patient must generate to initiate a ventilator breath; it may be set for pressure triggering or flow triggering Pressure trigger: cmh 2 O below baseline pressure Flow trigger: 1-3L/min below baseline flow 78

79 Ventilator Settings Parameter Description Typical Settings High pressure limit Regulates the maximal pressure the ventilator can generate to deliver the tidal volume; when the pressure limit is reached, the ventilator terminates the breath and spills the undelivered volume into the atmosphere cmh 2 O above peak inspiratory pressure 79

80 Complications of Mechanical Ventilation Ventilator induced lung injury Cardiovascular compromise Gastrointestinal disturbances Patient-ventilator dyssynchrony Ventilator associated pneumonia 80

81 Weaning Gradual withdrawal of mechanical ventilator and the re-establishment of spontaneous breathing are known as weaning. Begins only after the requirement for ventilator support has been corrected and patient stability has been achieved. 81

82 Weaning Length of time on ventilator, sleep deprivation and nutritional status also required to consider before start weaning. Factors that affect patient s ability to wean include ability of the lungs to participate in ventilation, respiration, cardiovascular performance and psychological readiness. 82

83 Readiness to wean All patients who are in mechanical ventilation should be screened daily to recognize their readiness to wean. The screen should include level of consciousness psychological and hemodynamic stability, adequacy of oxygenation and ventilation, spontaneous breathing capacity and respiratory rate and pattern. 83

84 Weaning methods Weaning method selected depend on the patient, patient s pulmonary status, and length of time on the ventilator. T-piece trials, SIMV, PSV are the main types of weaning methods. 84

85 T piece trials Involves alternating periods of ventilatory support (usually ACV or CMV) and periods of spontaneous breathing. The trial initiated by removing patient from ventilator and allowing breathing spontaneously on a T-piece oxygen delivery system. 85

86 T piece trials After a set amount of time, it is required to place the patient back on the ventilator again. The goal of this trial is to progressively increase the time which is spent off the ventilator. During the weaning process, the patient is observed closely for respiratory muscle fatigue. 86

87 SIMV The goal of SIMV weaning is the gradual transition from ventilator support to spontaneous breathing. Begins by placing the ventilator in the SIMV mode and slowly decreasing the rate. This method increase work of breathing. The patient should be closely monitored for signs of respiratory muscle fatigue. 87

88 Pressure Support This method consists of placing the patient on the pressure support mode and setting the pressure at a level that make easier the patient s achieving a spontaneous tidal volume of 10-12mL/Kg. PSV augments the patient s spontaneous breaths with a positive pressure. 88

89 Pressure Support During the weaning process, the level of pressure support is gradually reduce in increments of 3-6 cmh 2 O, while the tidal volume is maintained at ml/kg until a level of 5 cmh 2 O is achieved. 89

90 Weaning intolerance indicators Decrease level of consciousness Systolic blood pressure increased or decreased by 20mmHg Diastolic blood pressure greater than 100mmHg Heart rate increased by 20beats/minute Respiratory rate greater than 30 breaths per minute or less than 10 breaths per minute 90

91 Weaning intolerance indicators Respiratory rate increased by 10 breaths per minute Spontaneous tidal volume less than 250mL Arterial partial pressure of CO 2 increased by 5-10mmHg, ph less than 7.30 or both Oxygen saturation based on pulse oximeter less than 90% 91

92 Weaning intolerance indicators Use of accessory muscles of ventilation Diaphoresis Paradoxical chest wall movement or chest abdominal asynchrony 92

93 Nursing management of patient with mechanical ventilation Consult with other health care professional in selection of a ventilator mode (initial mode usually volume control with breath rate). Initiate setup and application of the ventilator. Ensure that ventilator alarms are on. Monitor ventilator settings including temperature and humidification frequently. 93

94 Nursing management of patient with mechanical ventilation Check all ventilator connections regularly. Administer muscle paralyzing agents, sedatives as ordered. Monitor for conditions that increase oxygen consumption (fever, seizure, shivering, pain). Monitor for factors that indicate increased work of breathing (lowered hed of the bed, biting of ETT, condensation in ventilator tubes). 94

95 Nursing management of patient with mechanical ventilation Monitor for symptoms that indicate increased work of breathing (increased heart rate or respiratory rate, increased BP). Use aseptic techniques when suctioning. Monitor pulmonary secretions for amount, color and consistency. Pause NG feeding during suctioning and 30 minutes before chest physiotherapy. 95

96 Nursing management of patient with mechanical ventilation Monitor for mucosal damage to oral, nasal and tracheal tissue. Promote adequate fluid and nutritional intake. Document all changes to ventilator settings with rationale for changes. 96

97 Nursing management of patient with mechanical ventilation Document all patient response to ventilator and ventilator changes (chest movement observations, changes in ABG, changes in X-ray). Ensure emergency equipment at bedside at all times (manual resuscitation bag connected to oxygen, masks, suction equipment etc.). 97

98 Summary Methods of delivery Complications of oxygen therapy Artificial airways Intubation and extubation Mechanical ventilation Nursing management 98

99 THANK YOU! 99