Respiratory System Assessment and Diseases Management PDF

RESPIRATORY SYSTEM Physiology of Breathing Physiologic Dead Space  Lung Compliance Lung compliance refers to the ease with which the lungs can be inflated 3 factors Elastin and collagen fibers Elastin – makes lung inflation more easily Collagen – make lung inflation more diff...

RESPIRATORY SYSTEM Physiology of Breathing Physiologic Dead Space  Lung Compliance Lung compliance refers to the ease with which the lungs can be inflated 3 factors Elastin and collagen fibers Elastin – makes lung inflation more easily Collagen – make lung inflation more difficult In pulmonary disease – elastin is replaced by fibrous (scar) tissue Water content Surface tension  Lung Compliance Low pulmonary compliance = less elastic = work of breathing - ex. Pulmonary fibrosis, ARDS, pulmonary edema Increase pulmonary compliance = more elastic = work of breathing - Overcompliance – ex. Emphysema >> loss of elastic recoil = air trapping = chest barrel Airway Resistance Refers to opposition to the flow of gases in the airways Factors Airway length, diameter, and flow rate of gases Increased airway resistance = more effort = inadequate ventilation Bronchoconstriction, presence of artificial airway Increased air flow Pulmonary perfusion Movement of blood through the pulmonary capillaries Perfusion Hypoxia induced vasoconstriction blood vessels in the pulmonary circulation are highly sensitive to alveolar oxygen levels and undergo marked vaso-constriction when exposed to hypoxia Purpose: to redirect blood flow away from the hypoxic regions of the lungs to those alveoli that are ventilated Generalized hypoxia (ex. Anemia, COPD, high altitudes) - Generalized vasoconstriction throughout the lungs = pulmonary hypertension = RV failure A While one is sitting or standing, the upper lobes are ventilated best, and the lower lobes are perfused best B While one is lying on one side, the superior lung is ventilated best, and the inferior lung is perfused best C In exercise ventilation and perfusion are increased and optimally matched throughout Pulmonary diffusion movement of gases between the alveoli, plasma, and RBCs Ventilation-Perfusion (V/Q) Mismatch Normal Ratio 1:1 ratio Healthy lungs Low Ventilation-Perfusion Ratio: Shunts Perfusion exceeds ventilation (1:2) Pneumonia, atelectasis, tumor, or mucus plug Ventilation-Perfusion (V/Q) Mismatch High Ventilation-Perfusion Ratio: Dead Space Ventilation exceeds perfusion (2:1) Pulmonary embolism, pulmonary infarction, cardiogenic shock Silent unit Absence of both ventilation and perfusion (0:0) Pneumothorax and acute respiratory distress syndrome Venous oxygen saturation (SvO2) Measurement of blood’s oxygen content returning to the right side of the heart Normal: 60-75% Increased SvO2 – decreased utilization (ex. Early septic shock, hypothermia) Decreased SvO2 – increased utilization (ex. Low cardiac output, fever, exercise, late stage of sepsis, acidosis or increased metabolic demands) Regulation of Breathing Respiratory Center Apneustic center ✓lower pons ✓Prolongs inhalation Pneumotaxic Center ✓Upper pons ✓Controls rate and pattern of breathing Brain damage connection to these 2 centers are lost, leading to irregular breathing pattern that consists of prolonged inspiratory gasps interrupted by expiratory efforts Regulation of Breathing Chemoreceptors Central – near respiratory center in medulla Peripheral – carotid and aortic bodies Normal person: respiratory drive – High CO2 in blood In patients with CHRONICALLY ELEVATED CO2 in blood - they no longer respond to elevated CO2 for breathing - respiratory drive: low oxygen levels - ex. COPD Assessment  Physical Assessment Health History 1. Tobacco use: delivery method, amount, and number of pack-years (number of packs of cigarettes per day × number of years smoking). 2. Occupational history, such as coal mining, asbestos work, and farming, and exposure to dust, fumes, smoke, toxic chemicals, paints, and insulation. 3. History of symptoms such as shortness of breath, dyspnea, cough, anorexia, weight loss, chest pain, or sputum production; further assessment of sputum, including amount, color, consistency, time of day, and whether its appearance is chronic or acute. 4. Use of oral and inhalant respiratory medications, such as bronchodilators and steroids. 5. Use of over-the-counter or street inhalant drugs. 6. Allergies: medication, food, or environmental. 7. Dates of last chest radiograph and tuberculosis screening. Inspection Tongue and sublingual area - Central cyanosis: bluish, gray, or dark purple tint Chest wall configuration - Barrel chest - Pectus carinatum and pectus excavatum - Spinal deformities: scoliosis, kyphosis, lordosis Evaluation of respiratory effort Systematic method for palpation, percussion, auscultation Palpation Position of trachea Midline Abnormal Findings Deviation to either side indicates pneumothorax – shift to opposite side Severe atelectasis – shift to same side Palpation Thoracic Expansion Normal findings: Equal thumbs should separate by 3-5 cm Abnormal Findings Unequal expansion – pneumothorax 70% SvO2 – 60-75% Pulmonary Function Test measure lung volumes and airflow to quantify respiratory function Purpose preoperative assessment evaluating lung mechanics diagnosing and tracking pulmonary diseases - Bronchodilator reversibility test monitoring therapy Takes 2 hours to complete Pulmonary Function Test Can be performed in intubated and non-intubated patients Intubated – spirometer is attached to the end of ET tube Non-intubated – a nose clip is attached on the patient, and is instructed to take a deep breathe, then exhale as hard, as fast, and for as long as possible Pulmonary Function test Before - Avoid scheduling immediately after mealtime - Avoid or HOLD all inhaled bronchodilator 6hr before - Assess for respiratory distress During - Assess for respiratory distress After - Assess for respiratory distress - Provide rest after procedure Carbon Dioxide Monitoring End-tidal carbon dioxide (PetCO2) Concentration of CO2 present at the end of exhalation Normal range: 35-45 mmHg Increased Hyperthermia, sepsis, seizures, hypoventilation, respiratory depression Decreased Hypothermia, cardiac arrest, pulmonary embolism, hyperventilation  Uses pH sensitive colored paper strips Uses - Verify ET placement - Verify enteral feeding tubes placement - low-resource settings Colorimetric device  using an electrode placed on the skin Commonly used in neonatal and pediatric patients Transcutaneous  measures the carbon dioxide level directly by a sensor in the exhalation port of the ventilator tubing Most commonly used Disadvantage - weight of the sensor on the ventilator tubing and possible obstruction of the sensor by Mainstream capnometer secretion  carbon dioxide gas is continuously aspirated through a side port in the ventilator tubing or nasal cannula and is measured and analyzed by a side unit Suitable for not intubated patients Disadvantages include obstruction of the sampling tube with secretions and slow Sidestream capnometer response time. Arterial Blood Gas Purpose Assess acid-base balance, ventilation, oxygenation ABG samples are obtained either by direct puncture of an artery, usually the radial artery by withdrawing blood through an indwelling arterial catheter system  Arterial Blood Gas: Nursing Responsibility Before: Indicate whether patient is using O2 (flow rate in L/min). Avoid change in O2 therapy or interventions (e.g., suctioning, position change) for 15 min before obtaining sample. During: Assist with positioning (e.g., palm up, wrist slightly hyperextended if radial artery is used). Collect blood in heparinized syringe. To ensure accurate results, expel all air bubbles. After: Apply pressure to radial artery for at least 5 min after specimen is obtained to prevent hematoma at the arterial puncture site.  Arterial Blood Gas Analysis 1. LABEL ALL VALUES (PACO2, HCO3, PH) if acidotic or alkalemic In pH, use 7.40 as reference. Then indicate if within normal or abnormal range (7.35-7.45) IF NORMAL RANGE, FULLY COMPENSATED, IF OUTSIDE RANGE, EITHER PARTIALLY COMPENSATED (OPPOSITE PACO2 AND HCO3) OR UNCOMPENSATED (NORMAL VALUE ISANG COMPONENT) 2. CHECK WHICH COMPONENT IS SAME AS PH 3. CHECK IF OTHER COMPONENT IS OPPOSITE – IF YES, COMPENSATED, REFER BACK TO PH IF NORMAL OR OUTSIDE; IF NOT, UNCOMPENSATED 4. OXYGENATION Acid-Base Imbalance Acid-Base Imbalance Acid-Base Imbalance Acid-Base Imbalance  Other diagnostic tests Sputum Studies rapid identification and treatment of pulmonary infections obtain a sputum sample by expectoration, tracheal suction, or bronchoscopy When the patient is unable to expectorate spontaneously, sputum may be collected by inhaling an irritating aerosol, usually hypertonic saline. This is called sputum induction. Collecting Sputum Specimen from ET or tracheostomy tube CT-Scan Diagnose suspicious lesions difficult to assess by conventional x-ray Types: ✓ High-resolution CT (HRCT) ✓Spiral / helical CT – used to diagnose pulmonary embolism CT-Scan Nursing Responsibility Before: Before contrast medium used, evaluate renal function. Assess if patient is allergic to shellfish, since the contrast is iodine based. Patient may need to be NPO 4 hr prior to study. During: Warn patient that contrast injection may cause a feeling of being warm and flushed. Patient must lie completely still during scan. After: Encourage patient to drink fluids to avoid renal problems with any contrast Magnetic Resonance Imaging (MRI) Used for in-depth diagnosis of lesions difficult to assess by CT scan and for differentiating vascular from nonvascular structures. IV contrast agent (gadolinium) may be given MRI Nursing Responsibility Before: Check for pregnancy, allergies, and renal function before test. Have patient remove all metal objects. Remove metallic foil patches. Contraindicated for persons with implanted metallic devices or other metal fragments unless noted to be MRI safe. Ask about any history of surgical insertion of staples, plates, dental bridges, or other metal appliances. Patient may need to be fasting. Assess for claustrophobia and the need for antianxiety medication. During: Patient must lie completely still during scan Positron Emission Tomography (PET) scan Glucose-containing nuclear tracer substance injected and taken up by metabolically active cells. Follow-up scan shows different colored tissues based on metabolic rate. Because cancer cells have an increased uptake of glucose, “hot spots” reflecting increased glucose consumption indicate the presence of active cancer. Used to distinguish benign and cancerous lung nodules. PET scan Nursing Responsibility Before: Obtain IV access to inject the tracer substance. Patients should be NPO, except for water and medications, for at least 4-6 hr prior. Low-carbohydrate diet 12 hours before schedule Hold glucose-containing IV solutions and change to normal saline. Check blood glucose levels. The glucose level must be between 60–140 mg/dL (3.3–7.8 μmol/L) for accurate glucose metabolic activity. During: Patient must lie completely still during scan. After: Encourage fluids to excrete radioactive substance. Treatment Modalities Topics Oxygen Therapy Artificial airways Endotracheal intubation Tracheostomy care Mechanical ventilation Chest / Thoracostomy tubes Oxygen therapy Oxygen Therapy Goal to provide a sufficient concentration of inspired oxygen to permit full use of the oxygen-carrying capacity of the arterial blood To ensure adequate cellular oxygenation, provided that the cardiac output and hemoglobin concentration are adequate. Primary indication: treat hypoxemia Oxygen Therapy Oxygen Therapy Indications for Oxygen therapy Significant hypoxemia Suspected hypoxemia (e.g., asthma, aspiration, seizure, drug overdose) Any acute care situation in which hypoxemia is likely ❑Increased myocardial workload (e.g., HF, hypertensive crisis, MI) ❑Decreased cardiac output (e.g., shock, hypotension, cardiopulmonary arrest) ❑Increased oxygen demand (e.g., sepsis, increased ventilatory work, trauma) ❑Before procedures that may cause hypoxemia (e.g., suctioning, during and after anesthesia, transportation of the unstable patient, bronchoscopy) Decreased oxygen-carrying capacity (e.g., carbon monoxide or cyanide poisoning, methemoglobinemia, sickle cell disease, anemia)  Principles of Oxygen Therapy Airway is always the first priority; oxygen is useless without an adequate airway. If high concentrations are needed, limit duration to prevent toxicity Frequent ABGs are mandatory if FiO2 is above 40 percent FiO2 can be estimated by counting the number of reservoirs Nose and pharynx only (1 reservoir) less than 40%: e.g., nasal cannula Nose and pharynx + mask (2 reservoirs) 40% to 60%: e.g., simple face mask Nose and pharynx + mask + reservoir bag (3 reservoirs) 60% to 80%: e.g., partial rebreathing mask Nose and pharynx + mask + reservoir bag + one-way valves (3 reservoirs + decrease in dilution) 80% to 100%: e.g., nonrebreathing mask Safety Guidelines for Oxygen therapy Keep the oxygen source at least 10 feet from open flame Do not allow smoking in a room with supplemental oxygen Do not use electrical appliances within 5 feet of the oxygen source. Do not use petroleum-based products around the oxygen source; use only water-soluble lubricants and creams Turn off the oxygen when not in use. Secure the oxygen tanks to prevent accidental dropping; keep the oxygen source away from heat or direct sunlight. Oxygen Delivery systems Low Flow Oxygen Delivery Systems Do not provide total inspired gas; the remainder of the patient’s inspiratory volume is met by the patient breathing varying amounts of room air. FiO2 dependent on the rate and depth of ventilation and fit of the device Criteria indicating that a low-flow O2 delivery system is acceptable Normal or near-normal VT (~7 ml/kg of ideal body weight [IBW]) Respiratory rate normal or near normal (~15–25 breaths/min) Regular respiratory rhythm Specific oxygen concentration not critical to patient’s care Devices under Low Flow Oxygen System Nasal cannula Reservoir systems Simple face mask Partial rebreathing mask Nonrebreathing mask High Flow Oxygen Delivery Systems Provide the entire inspired gas by a high flow of gas or entrainment of room air. Provide a predictable FiO2 but not necessarily a high FiO2 Criteria indicating that a high-flow O2 delivery system is needed VT is significantly less than or more than normal (~7 ml/kg of IBW) Respiratory rate less than 15 breaths/min or more than 25 breaths/min Irregular respiratory rhythm Specific oxygen concentration is critical to the patient’s care. Evidence of alveolar hypoventilation with hypercapnia Devices under High Flow Oxygen System Venturi Mask High-flow nasal cannula (HFNC) T-piece Trach collar Mechanical ventilator Minute Ventilation = RR X Tidal Volume Ex. Person in distress = 43 cpm x 450cc = 19350cc or 19.3L Non-rebreather Mask = High Flow Nasal Cannula 10lpm = 30lpm Partial Rebreather Mask Non-Rebreather Mask High Flow Nasal Cannula high-flow nasal cannula (HFNC) oxygen devices are capable of delivering well-humidified, blended, and actively warmed oxygen HFNC can provide oxygen at very high flow rates, between 30 and 60 L/min Can provide moderate PEEP. Complications of Oxygen Therapy Alveolar Hypoventilation / O2 induced hypoventilation At risk: in patients with COPD – breathing stimulus to high CO2 is lost Management Use oxygen with caution. Maximum 1-2LPM Target O2 saturation: 90% Complications of Oxygen Therapy Absorptive Atelectasis High concentrations of oxygen (an absorbable gas) wash out the nitrogen (a nonabsorbable gas) that normally holds the alveoli open at the end of expiration. Prevention Do not administer O2 that is not needed Avoid long duration of high concentrations of oxygen if not needed Complications of Oxygen Therapy Oxygen Toxicity Cause: too high O2 concentration over long period of time Pathophysiology Overproduction of oxygen free radicals Free radicals overwhelms neutralizing enzymes Damage to alveolar-capillary membrane Leads to ARDS Complications of Oxygen Therapy Oxygen Toxicity Sign and Symptoms Early substernal chest pain that increases with breathing Followed by dry cough and tracheal irritation and upper airway changes (ex. Nasal stuffiness, sore throat) Late CXR changes: atelectasis or pneumonia Decreased vital capacity Complications of Oxygen Therapy Oxygen Toxicity Prevention Use lowest FiO2 possible to maintain SaO2 of 90% Limit duration of 100% FiO2 to 60% FiO2 to 2-3 days Assess ABG if FiO2 is above 40% to ensure that high concentration is still needed Artificial airway Artificial Airway Oropharyngeal airway (OPA) Nasopharyngeal airway (NPA) Laryngeal mask airway (LMA) Endotracheal (ET) tube Tracheostomy tube  Oropharyngeal Airway used to relieve upper airway obstruction caused by tongue relaxation, secretions, seizures, or biting down on oral ETs indications: unconscious patients not recommended in alert patients because it triggers gag reflex causing vomiting Nursing interventions Remove airway every 24h to: Assess lips and tongue for pressure injuries Provide oral hygiene Oropharyngeal airway  Nasopharyngeal Airway Made of soft malleable rubber or soft plastic, the nasal airway ranges in sizes from 26 to 35 Fr Indications o Oropharyngeal airway is contraindicated due to oral trauma or during seizure o Conscious patients Insertion o Lidocaine and lubricant o Assess for patency – listen or feel for air movement during exhalation o Chevron tape technique  Nasopharyngeal Airway Nursing interventions Frequent assessment of pressure injuries and obstruction due to died secretions Need for airway assessed daily Rotation of airway from nostril to nostril on daily basis  Laryngeal Mask Airway is an ET with a small mask on one end that can be passed orally over the larynx to provide ventilatory assistance and prevent aspiration Placement of the LMA is easier than intubation using a standard ET Temporary airway Used in management of difficult airway insertion- “cannot intubate”  Endotracheal Tube most commonly used artificial airway for providing short-term airway management ETT is made of polyvinyl chloride or silicone material with distal cuff (balloon) that is inflated Purpose of the cuff is to facilitate ventilation by sealing the trachea and allowing the air to pass through, not around, the ETT. Indications o Maintain airway patency o Patients requiring mechanical ventilation o Severe airway obstruction o Also allows easier secretion removal o Protect from aspiration of oral or gastric contents  Endotracheal Intubation Insertion of ETT into the trachea through either the mouth or nose Orally inserted – preferred during emergency Nasally inserted – preferred in patients with oral trauma, jaw fracture and provides greater comfort overtime  Endotracheal Intubation 1. Preparation of materials 2. Preoxygenation with 100% oxygen for 3-5 minutes via bag valve mask connected to simple face mask 3. Premedicate – sedative (midazolam, propofol, diazepam) and paralytic (succinylcholine and rocuronium) 4. Positioning patient – sniff position 5. Placement of ET tube a. Each attempt limited to 30 seconds b. After insertion, check for bilateral breath sounds and equal chest movement c. End tidal CO2 detector – to initially verify placement after which the cuff is inflated d. Finally chest radiograph to confirm placement 6. Postintubation a. Level of insertion at the teeth is noted b. Secure ET tube using commercial tube holder Sniff Position  Tracheostomy tracheostomy tube provides an airway directly into the anterior portion of the neck indications Long term airway or mechanical ventilation Bypass an upper airway obstruction that prevents placement of ETT tube  Tracheostomy Methods Traditional – surgical tracheostomy – done in OR Percutaneous dilational tracheostomy (PDT) ✓ may be done bedside ✓Advantages: procedure is shorter and less expensive; perioperative infection rates are less ✓Contraindications - Inability to hyperextend neck - Morbid obesity  Tracheostomy Tube Designs Cuffed vs Uncuffed Single vs Double cannula Fenestrated vs unfenestrated tracheostomy tube Speaking tracheostomy valves  Tracheostomy Tube Designs Cuffed Patient require mechanical ventilation Prevent aspiration Used in short-term Uncuffed Patient does not require mechanical ventilation* Low risk of aspiration For long term  Tracheostomy Tube Designs Single Cannula Double Cannula Outer cannula – holds tracheostomy / airway open Inner cannula – removable; prevent tube occlusion from accumulated secretions by cleaning the inner lumen  Tracheostomy Tube Designs Fenestrated Have openings on outer cannula Allows the patient to speak and produce more effective cough Unfenestrated Do not have openings on outer cannula Patient is unable to speak  Tracheostomy Tube Designs Speaking valve device Allows patient to speak Uses one-way valve Cuff must be deflated first before attaching the speaking valve device* Mechanism of Speaking Valve Device Preparing the Patient for tracheostomy Pre-procedure Care Consent Ensure all appropriate personnel are present BVM, suction machine, emergency resuscitation equipment should be readily available, especially if bedside procedure Baseline vital signs Ensure patent IV line Position the patient supine Give analgesia and sedation as ordered Preparing the Patient for tracheostomy During the procedure Monitor hemodynamic status. Observe the patient’s response to analgesia and/or sedatives. Note the patient’s tolerance to the procedure. Observe the SpO2 and immediately notify the HCP if the SpO2 is less than 92% Preparing the Patient for tracheostomy Post-procedure Care Confirm correct tube placement (similar with ETT) Tracheostomy cuff is inflated Tracheostomy tube is sutured and secured in placed with tracheostomy ties, tapes, or Velcro strap Monitor vital signs Obtain chest x-ray Note and record ventilator settings, including mode, FiO2 and PEEP WOF complications: airway obstruction, bleeding, infection, potential dislodgment Nursing Management: Patient with Tracheostomy assess the tracheostomy site and confirm patency every shift, or more often based on your assessment Observe the site for any redness, inflammation, edema, ulceration, or signs of infection Perform sterile dressing changes every 12 to 24 hours Clean around the stoma with normal saline and apply a sterile precut dressing around the tracheostomy tube site Nursing Management: Patient with Tracheostomy Maintain cuff inflation pressure to 20-30 mmHg with cuff using manometer every 8 hours Higher cuff – tracheal necrosis Too loose – aspiration Minimal occluding volume (MOV) technique Suction tracheostomy as needed – sterile; try to avoid suctioning few hours after tracheostomy Change the tracheostomy tapes after the first 24 hours and PRN Types of Suctioning Closed Suctioning suction catheter that is enclosed in a plastic sleeve connected directly to the patient-ventilator circuit exposure to the patient’s secretions and infection is reduced for the patient and HCP’s safety Open Suctioning Performed when we need sterile sputum samples or CST is not available Best performed with 2 persons – one uses BVM, the other person suctions Higher risk for infection and exposure Closed Suctioning  Decannulation Removal of the tracheostomy from the trachea Indications The condition for tracheostomy is needed has been resolved - Hemodynamically stable - Stable, intact respiratory drive - Able to adequately exchange air - Independently expectorate secretions  Decannulation Pre-procedure Explain to the patient on what will occur Monitor vital signs Suction the patient’s airway, also clear any oral secretions Loosen or cut tracheostomy ties Remove any visible sutures Deflate the cuff Pull tracheostomy tube outwards in one smooth motion. Stop if there is resistance and inform HCP  Decannulation After removal Apply sterile occlusive dressing Monitor for bleeding, respiratory status, oxygen saturation Change dressing if soiled Close the stoma with tape strips Teach patient to splint the stoma with fingers when coughing, swallowing or speaking Epithelial tissue begins to form in 24 to 48 hours, and the opening closes within 4 or 5 days. Surgery to close the tracheostomy is usually not needed.  ACCIDENTAL Decannulation Immediately call for help !! If tube can be replaced (especially if tract has matured) Using hemostat Use hemostat to spread the opening where the tube was Insert the obturator in the replacement tube, lubricate the saline, and insert the tube into the stoma Once inserted, remove the obturator Using a suction catheter Insert suction catheter to allow air passage and guide for insertion Thread tracheostomy tube over the catheter, then remove the catheter  ACCIDENTAL Decannulation If tube can’t be replaced due to tract immaturity Immediately place patient in semi-fowlers position Cover the stoma with sterile dressing and ventilate the patient with the BVM over the nose and mouth Mechanical Ventilation Using a ventilator to deliver oxygen to the lungs a means of supporting patients until they recover the ability to breathe independently NOT CURATIVE Types of Ventilators Negative pressure ventilators o use of chambers that encase the chest or body and surround it with intermittent sub-atmospheric (or negative) pressure o ex. Iron lung used in polio o Uses: limited to chronic neuromuscular diseases and central nervous system problems o Rarely used for critically ill patients Positive pressure ventilators o Main method used for critically ill patients o During inspiration, ventilator pushes air into the lungs under positive pressure. Adjustable Ventilator Settings Respiratory rate – 6-20 breaths per minute Tidal volume – 6-10 ml/kg; 4-8ml/kg in ARDS O2 concentration (FiO2) – 21%-100% Peak Inspiratory pressure (PIP) – pressure the ventilator exert during inhalation to deliver the tidal volume. Once this pressure is reached, the ventilator ends the breath and spills undelivered volume into the atmosphere Adjustable Ventilator Settings Positive End-Expiratory Pressure (PEEP) ventilator setting in which positive pressure is applied to the airway during exhalation to keep airway or alveoli always open o During exhalation, airway pressure normally drops to near 0. o With PEEP, exhalation remains passive, but pressure falls to the preset PEEP level, often set between 5 to 10 cm H2O. Optimal PEEP – level of PEEP (pressure) to improve oxygenation without compromising hemodynamics Indication: ARDS, ARF Contraindications: traumatic brain injury, increased ICP, low CO, hypovolemia  Ventilator Settings 3 general categories Full support o Ventilator does most of the work of breathing for the patient o There is usually preset Tidal volume, Respiratory rate and PIP limit Partial support o Work of breathing is shared responsibility by the patient and ventilator o There may still be preset tidal volume and respiratory rate, BUT the patient assumes more responsibility Spontaneous mode o Work of breathing assumes almost all breathing o No preset respiratory rate and tidal volume. ONLY FiO2 and PEEP is provided by mechanical ventilation Full Support Modes Assist-control o The ventilator delivers preset tidal volume and respiratory rate o Usually used in postoperative patients and those with neuromuscular disorders and ARF o On AC, patient can take a breath whenever they want. However, it may cause hyperventilation / respiratory alkalosis Pressure control o Ventilator delivers pressure-limited breath o With preset respiratory rate and PIP, BUT NOT tidal volume = variable TV depending on lung compliance o Reduces risk of barotrauma o Used for noncompliant lungs Partial Support Modes Synchronized intermittent mandatory ventilation (SIMV) o Patient and ventilator shares the WOB o The ventilator delivers preset tidal volume at preset respiratory rate in SYNCHRONY with patient’s spontaneous breathing. o In between ventilator-delivered breaths, the patient can breathe spontaneously and achieve whatever tidal volume they achieve o used when the patient’s condition is too good for a full support mode of mechanical ventilation, but they are not yet ready for a spontaneous mode o Also used for weaning trials Spontaneous Breathing Modes pressure support o patient initiates breathing and the ventilator provides PRESSURE ONLY to airway during inspiration Continuous positive airway pressure (CPAP) o Do not confuse with noninvasive CPAP used in patients with sleep apnea o Ventilator only provides FiO2 and PEEP (pressure) Patient does almost all of breathing. Patient determines respiratory rate and tidal volume Nursing Management for Mechanically Ventilated Patients Maintaining Correct Tube Placement Note exit point from the mouth or nares Observe for symmetric chest wall movement and bilateral breath sounds During accidental decannulation Stay with the patient and try to maintain the airway (refer to accidental decannulation) Support ventilation with BVM Nursing Management for Mechanically Ventilated Patients Maintaining Proper Cuff Inflation Excess volume can cause tracheal necrosis Maintain cuff pressure at 20-30cm H2O Measure and record cuff pressure using minimal occluding volume q8H Nursing Management for Mechanically Ventilated Patients Maintaining Tube Patency Suction PRN, minimum at least 1 per shift Open vs Closed Suction Technique Hyperoxygenate client before and after suctioning. Limit each suction to 10 seconds or less Avoid excess suctioning – may lead to hypoxemia and bradycardia Closely assess patient’s ECG and O2 saturation before, during, and after suctioning If the patient does not tolerate, stop immediately Maintain adequate hydration, humidification, and frequent turning Nursing Management for Mechanically Ventilated Patients Maintaining Alarm Systems Temporarily suspend or silence alarms for up to 2 minutes for suctioning Ways to prevent alarm fatigue  Ventilator Alarms Low tidal volume High tidal volume Leaks or disconnection Anxiety, pain Low cuff pressure Change in patient condition (fever, increased metabolic Airway secretions demands, patient condition Oversedation improving)  Ventilator Alarms Low pressure limit High pressure limit Disconnections and leak Kinked or compressed tubing Loss of airway Increased lung compliance (ex. Peumothorax) Patient speaking Condensate or secretion in tubing Patient fighting ventilator (ventilator dyssynchrony) Improper alarm settings  Ventilator Alarms Apnea alarm Set for