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PaO2 - correct answer 80-100 mmHg
- can be used to assess efficiency of oxygenation SaO2 - correct answer 95-100% PaO2 means - correct answer partial pressure of oxygen in arterial blood (80-100 mmHg)
- creates the gradient for O2 diffusion from the alveoli into the blood, and from blood into capillaries and tissues SaO2 means - correct answer oxygen saturation of arterial blood (95-100%) 97% of blood's O2 is bound to Hgb ph < 6.8 or >7.8 - correct answer not compatible with life Normal range: 7.35-7. Common causes of respiratory acidosis (pH<7.35, PaCo2 >45 mm Hg) - correct answer COPD acute airway obstruction analgesia/sedation (drug related) trauma spinal cord injury chest wall injury neuromuscular disease hypoventilation w/ mechanical vent Something causing decreased breathing rate/depth, impacting gas exchange at the alveoli, excess fluid in the lungs, or body making more CO2 than it can exhale Common Causes of Respiratory Alkalosis (pH>7.45, PaCO2 <35 mm Hg) - correct answer hyperventilation/overbreathing, d/t hypoxia anxiety or fear pain stimulants pulmonary embolus
hyperventilation w/ mechanical vent Common Causes of Metabolic Acidosis (pH<7.35, HCO3<22) - correct answer May be caused by a non-pulmonary system, lactic acidosis ketoacidosis renal failure (acute/cx) rhabdomyolysis ingestion of acids (methanol, salicylates, ethylene glycol) diarrhea ileostomy pancreatic fistula Common Causes of Metabolic Alkalosis (pH>7.45, HCO3 >26) - correct answer (body will attempt to compensate by retaining CO2) interventions such as sodium bicarb given for cardiac arrest overingestion of antacids frequent blood transfusions loss of normal body acids d/t NG drainage, severe vomiting, diuretics steroid therapy Which organs/mechanisms respond to abnormal arterial blood pH? - correct answer Ventilation rate/depth changes to fix the pH (fastest method) Kidneys respond by altering rate of HCO3 production or elimination (slower, takes longer to affect pH) What is the ideal pH? - correct answer 7. pH < 7.2 - correct answer Critical Value: metabolic and chemical process will not function properly, heart will be irritable/dysrhythmic, vasoactive meds will not function properly What causes an increase in O2 needs? - correct answer - increase in altitude
- decreased cardiac output
- decreased Hgb levels
- poor lung perfusion
- reduced lung ventilation Low-Flow Oxygen Delivery Systems - correct answer Nasal cannula (1-8 L/min) Simple Facemask (usually 6-10 L/min, up to 50% O2) Partial rebreather
hemodynamically stable & hypoxemic respiratory failure extubation failure (avoiding reintubation) immunocompromised, early hypoxemic resp failure palliative care patients whose care goals are met w/ NIPPV chronic use for OSA, obesity hypoventilation syndrome, COPD, other NIPPV is NOT indicated for patients with _________ - correct answer apnea hemodynamic instability somnolence high aspiration risk inability to clear secretions unable to protect airway d/t AMS, confusion severe claustrophobia unable to remove mask in event of emesis continuous positive airway pressure (CPAP) - correct answer device used to treat sleep apnea; includes a mask that fits over the sleeper's nose and mouth, which is connected to a pump that pumps air into the person's airways, forcing them to remain open
- same continuous pressure throughout resp cycle
- decreases alveolar dead space, improves intrapulmonary shunt by opening alveoli
- decreases atelectasis, reduces WOB, reduces hypoxia bilevel positive airway pressure (BiPAP) - correct answer Ventilatory support used to treat patients with obstructive sleep apnea, patients with congestive heart failure, and preterm infants with underdeveloped lungs. 2 levels: inspiratory positive airway pressure (greater), expiratory positive airway pressure (lesser) IPAP: maintains open airways, increases tidal volumes, alveolar ventilation, improves hypercarbia, decreases WOB d/t pressure support at inhale EPAP: helps increase functional residual capacity, improves hypoxemia by keeping alveoli inflated at exhale Indication for Endotracheal Intubation - correct answer - pt can't maintain/protect a patent airway
- worsening respiratory failure
- needs more oxygenation, ventilation, despite NIPPV, supplemental oxygenation given Equipment for Intubation - correct answer Laryngoscope with several blades ET tubes
Malleable stylet 10 - ml syringe Tape/twill tape/securement device Magill forceps Water-soluble lubricant Suction unit, catheters, Yankauer, and tubing Bag-valve-mask and oxygen, Flow Meter, CO2 detector Stethoscope Air Entrainment Mask - correct answer Aka venturi/venti mask. Uses the Bernoulli principle, entrainment depends on O2 flow rate, size of jet and size of port. Creates increased flow rate to meet or exceed patient's inspiratory demand. Fixed FiO2s (more accurate at <40%) Total flow determined by air to O2 entrainment ratios. Uses = COPD requiring fixed FiO Reservoir system - correct answer Oxygen delivery system that provides a reservoir oxygen volume that the patient taps into when the patient's inspiratory flow exceeds the device flow e.g. nonrebreather mask Commonly used w/ patients who experience smoke inhalation, carbon monoxide poisoning Signs of Oxygenation Failure (Hypoxemic Resp Failure) - correct answer ABG: very low O (hypoxemia) w/ normal to low partial pressure of CO2 (PaCO2) CO2 diffuses more easily than O2, so problems w/ alveolar gas exchange will show in PaO2 levels before it shows in the PaCo2 levels Causes: Ventilation/Perfusion (V/Q) mismatch, hypoventilation, intrapulmonary shunting, diffusion defects (PE), pulm edema, COPD, bronchitis, PNA Extrapulmonary conditions: decreased cardiac output, low Hgb may lead to acute hypoxemic resp failure Signs of Ventilation Failure (Hypercapnic Resp Failure) - correct answer Alveolar and arterial O levels low, not enough gas getting into lungs and to alveolar-capillary membrane OTOH, CO2 is not being exhaled d/t ventilation being impaired, so PaCO2 in the alveoli rises and leads to high PaCO2 levels in the blood Cause: usually alveolar hypoventilation
systemic sepsis, hypovolemic shock r/t chest trauma or sepsis, acute pancreatitis, fat emboli, trauma, DIC, massive blood transfusions Pathophysiologic Effects of ARDS - correct answer - excessive alveolar capillary membrane permeability
- interstitial edema
- diffuse alveolar injury
- disruption of macrophage functions
- increased risk of infection ARDS Response Phases - correct answer Exudative response (72 hr after injury): lung inflammation, capillary leak, alveolar edema, destruction of alveolar 1 cells, compression of bronchioles, fluid exudation into alveoli - > Pt restless, rapid RR, WOB increasing, O2 near normal, CXR normal, wedge pressure may be normal, but pulmonary artery/pulmonary artery mean pressures high (means resistance in the lungs) Fibroproliferative phase : Type 2 alveolar cells destroyed, surfactant reduced, gas exchange deteriorates, lungs less compliant, increased peak inspiratory pressure. Pt may be hypoxemic refractory to treatment d/t developing interstitial fibrosis, alveolar atelectasis occurs w/ increased deadspace ventilation, V/Q mismatch ABG shows low PaO2, increased PaCO2 despite O2 given. Pt is tachypneic and PaCo2 lowers at first, then tiring, PaCO2 begins to rise again, pH drops (respiratory acidosis). Pt is crackly, CXR shows alveolar infiltrates. Pulmonary artery wedge pressure is NORMAL, unlike in cardiogenic pulmonary edema, but other PA catheter pressures rise and pt is at risk of right-sided HF. Pts w/ fibrosis have decreasing lung compliance, may go to pulmonary HTN and right-sided HF. Resolution phase: weeks to month, body remodels airways and vasculature, Type II alveolar cells restore alveolus, slow improvement of lung function O2 improves, lung sounds begin to clear, CXR slowly clears, airway compliance increases and airway pressures decrease Mechanical Ventilation Goals - correct answer - Smaller tidal volume 4-6 mL/kg = improved mortality, but reduced PaCO2 elimination
- Maintain pH of at least 7.20 by giving pt IV sodium bicarb, acidosis causes dissociation of O2 from Hgb and improves oxygenation
- Do not use permissive hypercapnia in pts w/ increased ICP, pulmonary HTN, seizures, or cardiac failure Ventilation Modes - correct answer - Pressure-regulated Volume Control (PRVC)
- Airway Pressure Release Ventilation (APRV)
- Pressure-Controlled Inverse Ratio Ventilation (PC-IRV)
- High Frequency Oscillatory Ventilation (HFOV) Alveolar Recruitment - correct answer e.g. PEEP, using pressure to open collapsed airways and alveoli, allowing for better gas exchange
- reverses intrapulmonary shunting
- leads to better oxygenation of the pt at lower FiO2 levels
- may use end tidal CO2 monitoring ARDS Patient Goals - correct answer - SpO2 >= 90% by invasive or noninvasive oxygen supplementation
- Continuous Tissue Perfusion Monitoring may be needed: arterial catheter placement for continuous arterial BP monitoring, easy serial ABGs, central venous O2 saturation (ScvO2) measurement to monitor tissue O2 consumption
- Manage Lung Fluid Balance: optimize Hgb, maintain euvolemia w/ fluid restriction and diuretics, invasive hemodynamic monitoring as needed
- Hemodynamics: pt is at risk of dysrhythmias, hemodynamic failure, evaluate for cardiac cause w/ continuous EKG assessment, vasoactive/inotropic meds as ordered to manage HR, preload, afterload, contractility and maintain adequate cardiac output Meds for ARDS Patients - correct answer - Corticosteroids: decrease inflammation
- Beta 2 Agonists: relax smooth muscles in airways
- Prostaglandins: selective pulmonary vasodilator to improve oxygenation
- Nitric Oxide: reduce vascular resistance of pulmonary vasculature Alveolar hypoventilation - correct answer A generalized decrease in ventilation that results in an increase in the PaCO2 and a consequent decrease in PaO2. Seen in conditions such as upper airway obstruction Reduced ventilator drive Respiratory fatigue Decreased chest wall compliance Best positioning for a pt w/ alveolar hypoventilation? - correct answer High or semi-high fowler's (30-90 deg), will allow for maximum lung expansion and help the muscles of ventilation to function properly The best ventilated areas should be in the most dependent position so they get the best gravity blood flow, and pt's position should be changed to maintain healthy tissue throughout the lung fields
- monitor VS and cardiac rhythm
- assess pain and agitation
- verify ventilator settings
- analyze ABGs after 30 min on ventilator Managing ETT Complications - correct answer - prevent skin breakdown around tube, reposition ETT from one side to another regularly to prevent inflammation and damage
- note location of ETT cm marking at teeth/gums/nares, document to assess for displacement
- assess for airway injury, displacement of tube
- prevent ventilator-associated events
- communicate w/ pts who are awake (writing, communication board) Preventing Ventilator-Associated-Events - correct answer - oral care: routine w/ CHG/ Peridex
- HOB: elevate to at least 30 degrees
- spontaneous awakening trials (SATs)/daily sedation interruptions
- peptic ulcer prophylaxis to prevent stress ulcer development (e.g. PPIs)
- VTE prophylaxis (SCDs, pharmacotherapy) SIMV (synchronized intermittent mandatory ventilation) - correct answer You get a set tidal volume, if the patient starts the breath they get the full volume Indications for Trach Tube - correct answer - pt will require long term mechanical ventilation
- hypercarbia
- unable to wean from ventilator
- obstruction of pt's upper airways
- pts have neuromuscular disease Complications of Trach Tubes - correct answer - tube displacement/obstruction
- tracheal collapse on expiration (tracheomalacia)
- scarring after removal/decannulation of tube
- tracheal stenosis/narrowing
- tracheoesophageal fistula
- tracheoinnominate artery fistula / bleed & hemorrhage Tracheostomy Tubes - correct answer A long-term breathing tube surgically placed through the anterior portion of the neck below the vocal chords.
- sized by measurement of inner diameter of tube (same as ETT)
- may have inner cannula that can be removed for cleaning / replaced w/ clean disposable cannula
- connected to ventilator tubing w/ same universal adaptor as ETT
- may be cuffed/uncuffed/fenestrated
- ideal length: tip of trach tube is a few cm above carina, may need longer for pts w/ thick necks, tracheal stenosis, tracheomalacia cuffed trach - correct answer Purpose: creates snug fit in trachea so as to: helps prevent aspiration, helps ventilator give stronger breaths, air won't get around it. Should be <25 cm H Only inflated if: patient is being mechanically ventilated, if inflation is specifically ordered by physician, with meals. If you have a cuffed trach, there is a tube that you can attach a syringe tube, you blow that cuff up. These are used for pt's that need ventilation, these trach tubes are blocked and sealed off by the cuff which is also a balloon so that no air can come down either side of it, the only way in or air is thru the tube, not around the tube Uncuffed intubation tube - correct answer Usually used for patients who can protect their own airway, have an adequate cough reflex and most importantly can manage their own secretions. Also for pts who are ready to be decannulated, pts w/ problems w/ their tracheostomies They remove the risk of tracheal damage caused by inflation of the cuff, may aid swallowing and communication with the concomitant use of a speaking valve. Fenestrated tube - correct answer Tracheostomy tube that is used when weaning a patient from a ventilator; has opening on outside cannula, allows the patient to speak even w/o speaking valve May be cuffed or uncuffed Decannulation Plug - correct answer Plug that can be inserted into the trach tube to force the pt to breathe through the upper airway to facilitate weaning/phonation Equipment for Emergent Reinsertion of Trach Tube - correct answer - spare trach tube should be kept close to pt for emergent reinsertion
- bag-valve-mask for supportive ventilation by placement over nose and mouth
- pts w/ total laryngectomy need BVM directly over stoma (upper and lower airways no longer communicate) Positive Pressure Ventilation Factors - correct answer - rate of flow
- volume of gas
- timing for ventilator cycles
- pressure w/in airways
If pt is breathing too rapidly, may need a different mode or sedation to limit the number of spontaneous breaths and prevent hyperventilation Pressure Control Ventilation - correct answer 1. A type of ventilatory support in which mandatory number of support breaths are delivered to the pt at a set inspiratory pressure 2.Indicated when O2 has been difficult to achieve, when pt has noncompliant lungs, poor oxygenation (ARDS, high Peak Inspiratory Pressure, plateau pressures)
- More even distribution of ventilation among lung units of equal compliances but unequal resistances Pt may need sedation and neuromuscular blockade to allow compliance w/ ventilator Intermittent / Synchronized Intermittent Mandatory Ventilation (SIMV) - correct answer Number of breaths is set, tidal volume is set, timing is synchronized with the pt's own inspiratory efforts Breaths the pt takes between ventilator delivered breaths are NOT assisted with a set tidal volume (Pt can breathe more often than the ventilator set rate, only ventilator set rate of breaths will get tidal volume delivered (other breaths are up to a pt's spontaneous tidal volume)) Pressure controlled - inverse ratio ventilation (PC- IRV) - correct answer 2:1, 3:1, 4:1 inspiratory to expiratory ratio is reversed paralyze this pt! IRV is not a mode, you must manipulate and adjust the inspiratory-time indicated when peak inspiratory pressure is >50cmH20, plateau pressures, pt has noncompliant lungs and need to prevent barotrauma PEEP / CPAP - correct answer preset pressure w/in the ventilator circuit at end of inspiration, commonly btwn 5-15 cm H20 (higher than 10 cm H20 can cause barotrauma)
- keeps small airways and terminal alveoli open during expiration, prevents atelectasis
- maintains functional residual capacity, improves oxygenation and lung volume
- internally stabilizes chest wall in conditions like flail chest Pressure Support Ventilation - correct answer **used only for spontaneously breathing patients, who might not have enough tidal volume The inspiratory and expiratory pressures are set, but there are no mandatory machine breaths (rate and tidal volume completely dependent on pt)
- Patients find this to be a more comfortable mode of mechanical ventilation. However, pressure support ventilation should only be used for patients with a stable respiratory drive (not sedated heavily) and stable lung compliance.
- Pressure support ventilation is typically used for patients who are weaning from mechanical ventilator support.
- may be adjunct to synchronized intermittent mandatory ventilation for non tidal volume supported breaths Pressure Regulated Volume Control (PRVC) - correct answer is a volume-targeted pressure control breath that is available on most ventilators. it delivers pressure breaths that are pt or time triggered, volume-targeted, and time cycled If the volume delivered is less than the set Vt the vent increases pressure delivery progressively over several breaths until the set and the targeted Vt are about equal. vise versa. Generally the vent does not allow the pressure to rise higher than 5 cm h20 below the upper pressure limit setting (pressure is a set range) clinician must determine why the high pressure is required to deliver the set volume e.g secretions, bronchospams. on the other hand when the pts lung conditions improves the pressure is less Airway Pressure Release Ventilation - correct answer Pressure control mode that utilizes an inverse ratio ventilation, AKA bi-level or bi-vent ventilation An applied continuous positive airway pressure that at a set timed interval releases the applied pressure for exchange of PaCO2 (long intervals of high CPAP, short intervals of low CPAP) May result in hypercapnia Pt can breathe spontaneously at any time, exhalation valve always open, less risk of barotrauma Used for pts w/ poor lung compliance (e.g. ARDS) How to Respond to a Ventilator Alarm - correct answer 1. ASSESS the patient
- Scan the ventilator panel to determine cause of alarm
- Manual ventilation w/ BVM if needed, unable to quickly correct, if pt in dsitress
- Obtain assistance Use viral filter on bag-mask circuit for Covid-19 pt, minimize BVM if possible Never leave pt's bedside w/ alarm silence/pause button activated Low Volume Alarm - correct answer what alarm is where patient doesn't receive preset Vt due to: disconnection of ETT,
SAT Safety Screen - correct answer Intracranial Pressure must be w/in normal limits Pt cannot be having active seizures Pt cannot be in active ETOH w/drawal No agitation Pt cannot be under influence of neuromuscular blocking agents Pt cannot have active myocardial ischemia NMBA - correct answer neuromuscular blocking agent (e.g. vecuronium/norcuron) blocks neural impulses to skeletal muscles, must always be used w/ adequate analgesia and sedation meds What are indications for NMBAs? - correct answer - Facilitate endotracheal intubation
- Assist with mechanical ventilation (after sedation and analgesia have been optimized) for pts w/ reduced pulmonary compliance (e.g. ARDS)
- Immobilization for selected procedures
- Increased intracranial pressure, control is important
- Prevention of shivering during implementation of cardiac hypothermia protocols
- Treat life threatening agitation refractory to aggressive sedation and analgesic therapy MUST BE USED W/ SEDATION AND ANALGESIA, AT LOWEST POSSIBLE DOSE, QUICKLY D/C WHEN NO LONGER NEEDED Train of Four (TOF) - correct answer Peripheral nerve stim used to assess level of neuromuscular blockage/see how pt's muscles respond after stim to the facial or ulnar nerve 0 twitches = 100% of receptors blocked, too much NMBA 1 twitch = 85%-90% of receptor blocked, may be adequate NMBA 2 twitches = 75-85% of receptors blocked (optimal NMBA) 3 twitches = up to 75% of receptors blocked, may not be enough NMBA 4 twitches = NO receptors blocked, pt may need more NMBA BIS Monitor - correct answer is one of several technologies used to monitor depth of anesthesia - > objective sedation monitoring system, uses EEG waves Recommended level of sedation for pt with NMBA: 40-60 on a 0-100 scale Level <40 only for pts needing anesthesia or burst suppression for status epilepticus
Cardiac Complications of Mechanical Ventilation - correct answer Elevated intrathoracic pressure lowers venous return to right atria of heart AND cerebral venous return:
decreased cardiac output - > decreased preload, decreased cardiac output, low organ perfusion
impaired cerebral venous return in a pt w/ impaired autoregulation can lead to increased ICP Barotrauma - correct answer peak inspiratory pressure is too high and alveoli rupture, causing pneumothorax, chest tube needed to decompress and facilitate lung re-expansion, air may also leak into tissues (subq emphysema) or mediastinum (cardiac tamponade) PIP should be < 35 cm H20 usually! Use smaller tidal volumes, prevent auto-PEEP, monitor airway pressure, increase expiratory time, minimize flow obstructions Looks like: pneumothorax, pneumomediastinum, subq emphysema Subcutaneous Emphysema - correct answer A characteristic crackling sensation felt on palpation of the skin, caused by the presence of air in soft tissues (appears as swelling or edema) Visible on CXR Volutrauma - correct answer The VOLUME of the air is more than the lungs can handle and physical damage to the lungs occurs Looks like: similar to early ARDS
- increase in permeability of alveolar-capillary membrane
- pulmonary edema
- protein and neutrophils in the alveolar spaces
- reduction in surfactant Pt is dyspneic, wheezing, frothy blood-tinged sputum! Frequently reassess the exhaled tidal volumes Use small tidal volumes (<6-10 mL/kg of predicted body wt of pt) Make sure to look for pt air trapping Ventilator-associated pneumonia (VAP) - correct answer significant potential complication because the artificial airway tube bypasses many of the lung's normal defense mechanisms: occurs in 21.8% of patients
Includes inspiratory reserve volume, expiratory reserve volume, tidal volume, a measure of lung tissue elasticity, and pt's ability to take a deep breath, cough, and clear their airway VC >= 10 mL/kg in pt = enough reserve to consider weaning Spontaneous Vt - correct answer volume of air exchanged in a normal breath / predicted body weight to get a standardized measure: needs to be GREATER or EQUAL to 5 mL/kg What is minimal ventilator support (FiO2)? - correct answer FiO2 < = 0. What are the most common methods of weaning from ventilation? - correct answer T-piece or trach collar CPAP: pt receives humidified O2 and CPAP while breathing own Vt and rate Synchronized Intermittent Mandatory Ventilation: allows longer periods of time btwn ventilator initiated breath, or gradual decrease in ventilator supported breaths / min, gradually decreased by 2 - 4 breaths every hr Pressure Support Ventilation: pressure level is set to allow for sufficient Vt w/ each spontaneous breath, then pressure slowly dropped in small increments, while monitoring pt for consistent Vt - > pt can extubate when pressure is minimal (5-7 cm H20) and Vt remains consistent Signs of Weaning Intolerance - correct answer - RR >35 or <
- O2 Sat is < 88%
- respiratory distress
- mental status change
- acute cardiac dysrhythmias
- increased dyspnea
- increased / decreased BP or HR
- shallow breaths, decreasing spontaneous Vt
- accessory muscle use
- increased anxiety
- deteriorating SpO2 or end tidal CO Positive Expiratory Pressure (PEP) - correct answer Airway clearance technique in which the patient exhales against a fixed orifice flow resistor to help move secretions into the larger airways for expectoration via coughing or swallowing burns wean assessment program (BWAP) - correct answer 26 factor bedside checklist, includes:
General: hemodynamics, factors r/t metabolic rate, nutritional status, pain control, anxiety level, adequate sleep/rest, GI information, general body strength, CXR improvement Respiratory Assessment: gas flow, WOB, airway clearance, strength, endurance, ABGs Extubation Equipment - correct answer - personal protective equipment
- suction equipment (sterile suction catheter, kit, tonsil-tip suction)
- non-invasive O2 delivery device
- 10 mL syringe, scissors
- emergency equipment in event of urgent need for reintubation Extubation Procedure Steps - correct answer Begin by explaining procedure to pt and family, tell pt to deep breathe, cough to mobilize secretions, improve breathing, voice will be hoarse
- Remove NG tube, hyperoxygenate, suction through the ETT
- Subglottic suctioning is performed before balloon deflation
- Wear appropriate PPE, remove ETT securement device, use the 10 mL syringe to completely deflate the pilot balloon. Auscultate neck area for an air leak indicating air movement through vocal cords!
- Tell pt to take deep breath, remove the ETT at end of inspiration in a smooth/quick manner (if glottis open at end inspiration, trauma to glottis and risk of laryngospasm is minimized)
- Instruct the pt to take deep breaths & cough. Suction w/ Yankauer to remove secretions.
- Pt may receive supplemental O2 via aerosol mask, NC to promote comfort and maintain oxygenation Monitoring Pt Post Extubation - correct answer - decreased LOC?
- SpO2 decreased?
- monitor for increased respiratory effort (lung excursion, lungs clear w/o distress)
- cardiovascular assessment (check for new dysrhythmias, hemodynamic instability)
- vital signs: monitor for increased/decreased BP, HR, RR
- ABGs often ordered post-extubation Give supplementary O2 as needed. Steps for Decannulation - correct answer Prior to Procedure:
- Decreasing size of tracheostomy
- Seeing if patient can tolerate passymuir valve (by viewing oxygen / saturation levels / not restless)
- Plug tracheostomy - once patient is able to tolerate tracheostomy for 24 hours, remove tracheostomy
- hyperoxygenate pt
