Airway Flashcards
What are indications for intubation?
Unable to swallow
Cannot ventilate/oxygenate (failed airway algorithm)
GCS is less than 8
Expected clinical course as a result of inhalation burns, circumferential neck or chest burns, or anaphylaxis
Apnea
Airway obstruction
Respiratory failure (pH less than 7.2, CO2 greater than 55, PaO2 less than 60)
What is the LEMON acronym for intubation?
Look Evaluate 3-3-2 Mallampati (1-4) Obstructions Neck Mobility
What is the Mallampati Airway Grading Scale?
Mallampati I: Soft palate, uvula, anterior/posterior tonsillar pillars visible (tall thin neck/no difficulty)
Mallampati II: Tonsillar Pillars hidden by tongue (no difficulty)
Mallampati III: Only the vase of the uvula can be seen (Moderate difficulty)
Mallampati IV: Uvula cannot be seen (short, fat or muscular neck/severe difficulty)
How are the Macintosh and Miller laryngoscope blades different?
Macintosh: curved blade used to lift the vallecula
Miller: straight blade used to lift the epiglottis
What are the airway visualization aid methods?
Sellick’s Maneuver: Direct downward pressure on the thyroid cartilage occluding the esophagus and prevents aspiration during intubation
BURP: Backward Upward Rightward Pressure
What is the Failed Airway Algorithm?
Patient requires a secured airway
3 attempts of direct laryngoscopy unsuccessful
Ventilate patient with BVM
Unable to ventilate/oxygenate SaO2 greater than 90%
Cricothyroidotomy indicated
How can ET tune placement be confirmed?
Chest X Ray is the gold standard (distal tip should be 2-3 cm or 1” above carina or level of T2/T3 vertebrae
Visualization of tube passing through the cords is the next best method
Bulb tube check: attached bulb will not re-inflate if tube is in esophagus
ETCO2: if ETT is in trachea there will be CO2 in expired air
What are the 7 P’s of Intubation?
Preparation Preoxygenate Pretreatment Paralysis with induction Protect and position Placement with proof Post intubation management
What is the LOAD acronym for RSI pretreatment?
Lidocaine
Opiates
Atropine
Defasiculating dose
What differentiates the 3 main neuromuscular blockers?
Succinylcholine (Anectine): depolarizing neuromuscular blocker that causes fasiculations has a short onset and duration. Dose is 1-2mg/kg. Contraindications include Hyperkalemia, crush injuries, eye injuries, narrow angle glaucoma, history of malignant hyperthermia, burns for greater than 24 hours, any nervous system disorder. Known to lead to malignant hyperthermia which is treated with 3mg/kg Dantrolene
Vecuronium (Nocuron): non depolarizing neuromuscular blocking agents which does not cause fasiculations. Often used after succinylcholine to maintain paralysis. Defasiculating dose reduces intubation ICP increase. Longer onset and duration. Dose 0.04-0.06mg/kg after succinylcholine. Only one of 3 which does not require refrigeration.
Rocuronium (Zemeron): non depolarizing neuromuscular blocking agents which does not cause fasiculations. Often used after succinylcholine to maintain paralysis. Defasiculating dose reduces intubation ICP increase. Longer onset and duration. Dose 0.1-0.2mg/kg every 20-30 min maintenance
What are the 3 main sedation induction agents?
Etomidate (Amidate): preferred for awake sedation due to short onset and duration. Minimal change in BP and CO. There are no analgesic properties. Vomiting can occur when waking up. Contraindications include some adrenal suppression occurs so do not use in septic shock or Addison’s disease
Midazolam (Versed): used for sedation by helping to forget an event ever happened (anterograde amnesia) and for seizures. Flumazenil (Romazicon) is reversal agent.
Propofol (Diprivan): Hypnotic with no analgesic properties. Dose is average 1.5mg/kg IV. Decreases CPP and MAP. Not used in head injury or or for hemodynamically unstable pts
What are the 3 main analgesic induction agents?
Ketamine (Ketalar): Hypnotic analgesic amnesic used to stop pain impulses. Potent bronchodilator. Does not dry airway secretions, can increase them in which case 0.01 mg/kg IV Atropine or 0.3mg IV Scopolamine slowly. Hallucinations can occur upon waking.
Morphine: Opioid analgesic. Avoid in patients with head injury or respiratory depression. Hypotension, nausea, and flushing can occur.
Fentanyl: Opioid analgesic that is 100x more powerful than morphine. Avoid in patients with increased ICP, hypoventilations, hypotension, and bradycardia. Chest wall rigidity can occur.
How do tidal volume, inspiratory reserve volume, exploratory reserve volume, vital capacity, residual volume, total lung capacity, and dead space relate to each other?
Tidal volume is how much air the patient breathes in a regular breath. Inspiratory reserve volume is the amount of air that can be forcefully inhaled in addition to the tidal volume breath. Exploratory reserve volume is the amount of air that can be forcefully exhaled after a tidal volume breath. These three components together are the vital capacity. Add on to this the residual volume or the amount of air remaining in the respiratory system after that exploratory reserve volume and you have the total lung capacity. Dead space is simply the term for all the airway surfaces not a part of the gas exchange process which is approximately 2ml/kg.
What are the two classifications of chemoreceptors?
Central chemoreceptors are located in the medulla/pons and its response is dictated by H and CO2 levels
Peripheral chemoreceptors are located in the aortic arch/carotid bodies. Their response is dictated by CO2, O2, and H levels.
What is the Fick Formula?
A measurement of cardiac output based on the principle that oxygen uptake by the lungs is equal to O2 delivery for the sake of determining how much O2 a person is using
What are the two types of respiratory failure?
Hypoxic respiratory failure or when the PaO2 is less than 60 is treated by increasing tidal volume and FiO2 followed by the rate.
Hypercarbic respiratory failure or when the CO2 is greater than 55 or patient is in respiratory acidosis is treated by increasing tidal volume then the rate.
What are the five main abnormal respiratory patterns?
Apneustic respirations involve deep gasping then a pause and a brief breath out. This is commonly associated with decerebrate posturing.
Ataxic respirations involve completely irregular breaths with irregular pauses and points of apnea. These are caused by medulla injury from stroke or trauma and typically indicate a very poor outcome.
Biots respirations involve quick shallow breaths followed by apneic periods which can either be irregular or regular. This is also caused by medulla injury from trauma or stroke or pressure on the medulla as a result of brainstem herniation.
Cheyne-Stokes respirations involve breaths that get progressively deeper and potentially more rapid with a gradual decrease afterwards that ends in an apneic period. This is typically tied in with decorticate posturing and brainstem herniation/Cushing’s triad.
Kussmaul’s respirations involve breaths that gradually develop into labored, deep, and gasping breaths. This is typically indicative of DKA.
What are the gold standards of oxygenation and ventilation?
Ventilation gold standard is ETCO2.
Oxygenation gold standard is SPO2.
What is the number one cause of healthcare related death in the U.S.?
Ventilator acquired pneumonia
What is meant by the term Curare Cleft?
Tick marks on capnography waveform indicative of choking on ET tube and need of repeat paralysis and repeat sedation.
What are the ventilator settings?
Tidal Volume: 6-8 ml/kg
Rate: 8-20 breaths/min
Minute volume: Rate x Tidal Volume (4-8 L/min)
I:E ration: 1:2, unless asthmatic in which case 1:4
FiO2: 21%-100%
Pplat (static end inspiratory recoil pressure of respiratory system/lung and chest wall): less than 30
PEEP: 5
PEFR (Peak Expiratory Flow Rate): 500-700 L/min for men, 380-500 L/min for women
What are the 6 main modes of ventilation?
Controlled Mandatory Ventilation
Synchronized Intermittent Mandatory Ventilation
Assist Control Ventilation
Pressure Control Ventilation
CPAP
BPAP
What are the 5 most common causes of Low Pressure Alarms on ventilator?
Patient disconnection from machine
Chest tube leak
Circuit leak
Airway leak
Hypovolemia
What are the 6 most common causes of high pressure alarms on the ventilator?
Kinked line
Coughing
Secretions in airway
Patient biting tube
Reduced lung compliance from ARDS or pneumothorax
Increased airway resistance
In what instances is preoxygenated required prior to flight?
O2 10 L/min by NRB for 15 minutes before takeoff recommended for obese patients as a result of bariobarotrauma from sudden nitrogen release of lipid nitrogen stores at altitude, pregnant patients, and pediatric patients.
What precautions are required for TB and Meningitis?
Tuberculosis is carried in sputum which means gloves, mask, gown, respirator, and eye shield are required
Meningitis is carried in CSF which means gloves, mask, and gown are required
What are the key points of Asthma and COPD?
Both:
Flattened diaphragm on CXR, chest cavity is overexpanded from air trapping
Capnography waveform has shark fin appearance
Differences:
Asthma treatment includes: increase I:E to 1:4, high FiO2, bronchodilators, IV Fluids, and Ketamine is RSI is required
COPD treatment includes: low FiO2, nebulizer/duo-neb, high tidal volume 10ml/kg, increase PEEP to 10
Asthma important point: decreased or absent wheezing is serious and indicates impending respiratory failure
COPD important point: chronic bronchitis pts typically referred to as blue bloaters. Emphysema pts typically referred to as pink puffers to due to pink color from polycythemia vera
What are the key points of pneumonia?
Typically viral, at times bacterial
CXR shows pleural effusions, lobar consolidation (right middle lobe pneumonia is most frequent site)
Treatment includes O2, IV fluids, bronchodilators, and antibiotics if bacterial
What are the key points of ARDS?
ARDS or acute respiratory distress syndrome is most commonly caused by pancreatitis (commonly occurs in conjunction with ARDS), sepsis, trauma, or aspiration pneumonia
CXR will show ground glass appearance, patchy infiltrates, bilateral diffuse infiltrates
Swann-Ganz will show increased PAWP (18-20) because right heart pressure is pumping against increased resistance in the lung vasculature
Treatment will include increase PEEP to greater than 10 and tidal volumes greater than 10 ml/kg
