Clinical Application of Mechanical Ventilation PDF

Clinical Application of MECHANICAL VENTILATION Fourth Edition David W. Chang  Chapter 6 Airway Management in Mechanical Ventilation  Airway Management Review, Pt. II  Intubation Endotracheal tube – Oral or nasal Tracheostomy tube – Inner ca...

Clinical Application of MECHANICAL VENTILATION Fourth Edition David W. Chang  Chapter 6 Airway Management in Mechanical Ventilation  Airway Management Review, Pt. II  Intubation Endotracheal tube – Oral or nasal Tracheostomy tube – Inner cannula  Intubation Indications for using artificial airways  Would You Intubate? Case 1: A patient is on fluid overload due to congestive heart failure. She is SOA, ABGs are – pH 7.32; PaCO2 68; HCO3 25; PaO2 54. Case 2: A patient whose ABGs are near normal with a dx. of myasthenia gravis. Case 3: A patient whose ABGs are – pH 7.02, PaCO2 28, HCO3 8, PaO2 78. The patient is in diabetic ketoacidosis.  Common Artificial Airways in Mechanical Ventilation Endotracheal tube – Oral intubation: uncomfortable, gagging, excessive secretions – Nasal intubation: better tolerated, suitable for patients with trimus (lockjaw), oral trauma or deformities, mandible fracture, and short neck – Nasal intubation: harder to insert than oral intubation, smaller ET tube and higher airflow resistance, incidence of sinusitis – High-Lo Evac tube can remove subglottic secretions  Special tracheostomy Common devices Talking tracheostomy tube Artificial continuous flow with thumb Airways port speaking valves in High-volume low-pressure cuff: foam, self-inflating Mechanic Tracheostomy button al Direct access to trachea for removal of secretions Ventilatio Temporary or permanent basis n May be replaced with tracheostomy tube without repeated surgery  Intubation Procedure Pre-intubation assessment to rule out contraindications – Head injury, cervical spinal injury, airway burns, and facial trauma Signs of difficult airway – Large tongue, neck mass, anterior larynx position, decreased mandibular space, reduced mouth opening, limited neck extension, dental overbite Intubation Procedure  Intubation Procedure Intubation supplies – Laryngoscope (battery and light source) – Blade (size 00 to 4) Miller (straight), lifts up epiglottis Macintosh (curved), placed at vallecula (between base of tongue and epiglottis), lifts up tongue and indirectly the epiglottis – ET tube (size 2 to 10 − internal diameter in mm) radiopaque line pilot balloon – 10-mL syringe – Water-soluble lubricant  Intubation Procedure Intubation supplies (continued) – Tape or ET Tube Holder – Stethoscope – Stylet To provide curvature of ET tube Optional for oral intubation Not used in nasal intubation – Topical anesthetic Optional – Magill forceps Required for nasal intubation Intubation Procedure Special visualization devices – Fiber-optic endoscope – Lighted stylet – Flexible fiberoptic stylet – Video system Selection of Endotracheal Tube Intubatio n Procedur e  Intubation Procedure Ventilation and oxygenation – Pre-oxygenation with 100% O2 – Bag/mask ventilation if necessary – Each intubation attempt limited to 30 sec – Re-oxygenate and bag/mask ventilation before retry – Seek assistance after 3 unsuccessful intubation attempts Intubation Procedure Continues  Continued Intubation Procedure Intubation Procedure Continues  Intubation Procedure Continued  Intubation Procedure Common problems during intubation  Intubation Procedure: Checking Success Signs of endotracheal intubation – Bilateral breath sounds Listen for breath sounds along midaxillary line because esophageal air sounds may transmit to anterior thorax Breath sounds may be abnormal (e.g., diminished, crackles, wheezes) – Lack of vocal sounds No airflow through the vocal cords after cuff inflation – Air movement at ET tube opening if breathing spontaneously – Immediate improvement of SpO 2 – Positive exhaled CO2 indicator  Intubation Procedure Signs of esophageal intubation – Absence of breath sounds Listen for breath sounds along midaxillary line because esophageal air sounds may transmit to anterior thorax – Rapid deteriorating vital signs and SpO 2 – Gastric sounds and distention with bag/mask ventilation – Aspiration Esophageal detection device (syringe or bulb) – Rapid filling of syringe or deflated bulb if ET tube is in trachea – Delayed filling of syringe or deflated bulb if ET tube is in esophagus (esophagus is normally in a constricted state) – Should not be used if excessive air is present in stomach Rapid Sequence Intubation Rapid sequence intubation (RSI) is done in a controlled setting (Figure 6-13 in textbook) – Pre-RSI medications should include a sedative (e.g., etomidate) and a short- acting NMB agent (e.g., succinylcholine) – Analgesic is needed only for pain management Rapid Sequence Intubation Management of Endotracheal and Tracheostomy Tubes Securing endotracheal and tracheostomy tubes  Management of Endotracheal and Tracheostomy Tubes Cuff pressure – Capillary perfusion pressure in trachea is 25 mm Hg to 35 mm Hg – Cuff pressure should be