Management of the Airway SAUSHEC Medical Student Lecture Series

Management of the Airway SAUSHEC Medical Student Lecture Series 4/24/2008 Introduction to Airway Management • The first priority in patient care; the “A” of the ABC’s • Rapid airway intervention is critical to prevent CNS injury and death • Knowledge and skill in airway management techniques are vital for successful outcome Pathophysiology of Airway Compromise • Etiologies – Trauma – neck, CNS, multi-trauma – Infection – pneumonia, epiglottitis – Edema – Anaphylaxis, angioedema – Tumor – Head and Neck CA – Foreign body – Anatomic anomalies Pathophysiology (Cont) • Complete obstruction- physiologic response – cyanosis – patient distressed; unable to cough, speak, or breathe – unconsciousness, apnea – increased HR and BP – bradycardia, asystole Basic Maneuvers • Supplemental oxygen • Opening the airway • Airway adjuncts Supplemental Oxygen • Indicated for any seriously ill or injured patient • May vary oxygen concentration delivered by using various devices • Use 100% O2 for any critical patient • Provides oxygen reserve prior to intubation Opening the Airway • • • • Head and jaw positioning Abdominal thrust Laryngoscopy with forcep extraction Suction Head and Jaw Positioning • Head tilt – do not use if possible c-spine injury – combine with chin lift/jaw thrust to maximize airway patency • Chin lift / jaw thrust 4/24/2008 Abdominal Thrust • Indicated in a conscious patient with: – total airway obstruction – partial obstruction with poor air exchange • avoid use in: – infants <1 yr – pregnant or obese patients Forcep Extraction • Preferred method in unconscious patient • Direct visualization of foreign object with laryngoscope • Removal of foreign body with Kelly or Magill forceps Suction • Used to clear blood, secretions, and particulate matter from the airway • Most effectively and safely used under direct visualization Airway Adjuncts • Oropharyngeal airway – prevents tongue from falling onto pharynx and occluding airway – use only in the unconscious patient – can obstruct airway if improperly placed Airway Adjuncts • Nasopharyngeal airway – may use in semiconscious or unconscious patient 4/24/2008 Endotracheal Intubation • Basic Orotracheal intubation • Rapid sequence intubation • Nasotracheal Orotracheal Intubation • Indications “VSOP” – Ventilation – apnea, hypercapnia – Secretion control – Obstruction – tumor, FB – Protection – head injury, edema, etc. – Also: Drug admin in ACLS Orotracheal Intubation (cont) • Contraindications – No absolute contraindications – Use caution and immobilization in patients with potential cervical spine injury Orotracheal Intubation • Technique – Equipment preparation – Pre-oxygenation – Laryngoscopy – Tube insertion – Confirm tube placement – Anchor tube Orotracheal Intubation • Preparation “SOAP ME” – Suction – Oxygen – Airways – Pre-medication – Monitors – Equipment for failure 4/24/2008 Orotracheal Intubation • Preoxygenation – Denitrogenation of FRC – 100% O2 for 5 minutes provides up to 5 minutes of complete apnea before desaturation < 90% – 4 breaths at full vital capacity provide 60-80% of same effect – Essential to eliminate bag valve mask ventilation of patient 4/24/2008 Orotracheal Intubation • Technique: laryngoscopy • insert blade into right side of mouth, sweeping tongue to left • lift laryngoscope along line of handle, do not leverage teeth • cricoid pressure, suction as needed, visualize cords Orotracheal Intubation • Technique: Tube Placement – tube insertion • insert tube into right side of mouth and watch it go through cords • inflate balloon 4/24/2008 Orotracheal Intubation (cont) • Technique problems – Improper position of patient’s head/neck – Not clearing tongue from line of sight – Leveraging laryngoscope against teeth Orotracheal Intubation (cont) • Complications – Right mainstem intubation – Esophogeal intubation – Aspiration – Dental trauma – Vocal cord spasm/injury Rapid Sequence Intubation • Use of pharmacologic adjuncts to intubation to induce rapid sedation and paralysis • Allows immediate control of the airway • Minimizes the risk of aspiration • Optimizes conditions for successful intubation Rapid Sequence Intubation • Indications – Facilitate emergent intubation – Evidence of increased intracranial pressure Rapid Sequence Intubation • Contraindications – Inability to perform orotracheal intubation – Not prepared to obtain surgical control of the airway – Unresponsive patient/Cardiac arrest (unnecessary delay to intubation) Rapid Sequence Intubation • Technique – Preparation and preoxygenation as per general OT intubation – Premedication – Sedation – Paralysis – Intubation Premedication • Defasiculation – Pancuronium or vecuronium 0.01 mg/kg rapid IV push – May prevent succinylcholine associated fasciculations – May prevent increased intragastric, intracranial, and intraocular pressure Premedication • Lidocaine – Used to suppress cough reflex and increased intracranial pressure response in patients with head injury – Dose: 1.5 mg/kg IV over 30-60 seconds Premedication • Atropine – Prevent succinylcholine induced bradycardia – Pre-treat children < 8; adults if given repeat dose of succinylcholine – Dose: 0.01 mg/kg IV push (min 0.2 mg) Sedation • Etomidate – Ideal agent for ED RSI: Few hemodynamic effects, positive cerebro-protective effects – Non-barbituate sedative – Rapid onset and offset – Dose of 0.3 mg/kg IVP 4/24/2008 Sedation • Thiopental – Barbiturate- rapid acting, brief sedation – Alternative in adult patients with head trauma who are hemodynamically stable – Adverse effects: hypotension, respiratory depression – Dose: 3-5 mg/kg IV push Sedation • Fentanyl – Potent narcotic analgesic with rapid onset and short duration – Adverse effects- respiratory depression, chest wall rigidity if >10 ug/kg given rapidly – Dose: 2-3 ug/kg at rate 1-2 ug/min; titrating to effect Sedation • Midazolam – Rapidly acting benzodiazepine with short duration of action and an amnestic effect – Adverse effects: respiratory depression, hypotension – Dose: 0.02-0.04 mg/kg Paralysis • Succinylcholine – Drug of choice for ED RSI – Depolarizing paralytic agent, onset of paralysis in 1 minute, offset < 5 mins – Adverse effects: muscle fasciculations, hyperkalemia, vagal stimulation, and malignant hyperthermia – Dose: 1.5 mg/kg IV push Paralysis • Always administer cricoid pressure prior to paralysis and continue until cuffed ET tube is in place and confirmed! Intubation • Always confirm ETT placement • Auscultate over all lung fields and epigastrium • Confirm CO2 return by colorimetry • Post-intubation CXR 4/24/2008 Nasotracheal Intubation • Indications – Difficult/impossible direct laryngoscopy – Alternative to orotracheal intubation in: awake patients requiring intubation with spontaneous respirations Nasotracheal Intubation • Contraindications – Apnea – Basilar skull fracture – Anticoagulant use or coagulopathy – Airway foreign body, abcess, or tumor – Severe midface trauma Nasotracheal Intubation • Technique – Equipment preparation – Patient positioning – Tube insertion – Confirm placement – Anchor tube Nasotracheal Intubation • Helpful hints – Occlude opposite nostril – “whistling” cap for ET tube – Cricoid pressure when passing tube – If breath sounds decrease, pull back – Direct visualization technique using Magill forceps Nasotracheal Intubation • Complications – Esophogeal intubation – Aspiration – Nasal trauma / epistaxis – Posterior pharyngeal wall perforation – Vocal cord injury Surgical Airways • Cricothyrotomy • Percutaneous Transtracheal Ventilation (needle cricothyrotomy) Cricothyrotomy • Indications – Failure of oral or nasal intubation – Upper airway obstruction unrelieved with other measures – Injuries making oral or nasal intubation difficult or dangerous, especially to the midface Cricothyrotomy • Contraindications – Patients without contraindications to oral or nasal intubation who can be successfully intubated – Severe trauma to larynx, cricoid cartilage, or a transected trachea – Children under 10-12 years old Cricothyrotomy • Technique – Locate membrane – Sterile skin prep and anesthesia – Incise skin with vertical incision – Incise membrane with horizontal stab – Dilate incision – Insert dilator and place tube – Shiley or 6.0 ETT tube 4/24/2008 4/24/2008 Cricothyrotomy • Complications – Bleeding – cricothyroid artery runs superiorly – Injury to adjacent structures – Incorrect tube placement – Infection – Subglottic stenosis Transtracheal Ventilation • Indications – Same as surgical cricothyrotomy – Surgical airway of choice for children under 12 years old – Contraindications as for surgical cricothyrotomy Transtracheal Ventilation • Technique – Locate membrane – Anesthesia and sterile skin prep – Using 14 G catheter over needle, puncture skin and then membrane – Advance catheter and withdraw needle – 3.0 ETT connector fits – Attach to oxygen/ventilation device – 50 PSI minimum, 1s on, 2-3 off Transtracheal Ventilation • complications – Subcutaneous emphysema – Kinking or blockage of catheter – Bleeding – Infection – Incorrect placement – Damage to surrounding structures Pediatric Airway Management • Anatomic differences • Basic maneuvers • Orotracheal intubation Pediatric Anatomic Differences • • • • • Head and occiput relatively larger Airway smaller Larger tongue/oropharynx ratio Larynx higher and more anterior Narrowest portion of airway is at cricoid Pediatric Basic Maneuvers • Opening the airway – “Sniffing” position ideal – Avoid hyperextension-may occlude airway – Avoid hyperflexion-may make visualizing the glottis difficult – Chin lift/jaw thrust indications as in adult Pediatric Basic Maneuvers • Bag-valve-mask – Often can ventilate despite significant upper airway obstruction – Tidal volume 10-12 cc/kg – Use with 100% oxygen – Use cricoid pressure to avoid gastric distention Pediatric Orotracheal Intubation • Technique similar to adult intubation • Equipment different – straight blades in up to age 4-5 years – uncuffed tubes in patients <8 years old – estimate tube size by size of little finger, or age formula or tables – (16 + Age)/4 • Be familiar with equipment and anatomy Equipment Guidelines According to Age and Weight Equipment Airway Oral Breathing Self-inflating bag O2 ventilation masks Endotracheal Tube Laryngoscop e Premie (1-2.5 kg) Infant 00 Infant Neonate (2-4.0 kg) Small 0 Infant 6 months (7.0 kg) Small 1 Child 1-2 years (10-12 kg) Small 2 Child 5 years (16-18 kg) Small 3 Child 8-10 years (24-30 kg) Small 4.5 Child/Adult Premature Newborn Infant/Child Child Child Small Adult 2.5-3.0 uncuffed 0 (straight) 3.0-3.5 uncuffed 1 (straight) 3.5-4.0 uncuffed 1 (straight) 4.0-4.5 uncuffed 1-2 (straight) 5.0-5.5 uncuffed 2 (straight or curved) 5.5-6.5 uncuffed 2-3 (straight or curved) Suction Circulation BP cuff Venous Access Angiocath 6 Newborn 22-24 6-8 Newborn 22-24 8 Infant 22-24 8-10 Child 20-22 10 Child 18-20 10-12 Adult 16-20 Difficult Airway • Predicting the difficult airway – Rule of 3s • 3 fingers between upper/lower teeth • 3 between mandible and hyoid • 3 between thyroid and sternal notch – Predicts success • Deficit in 2 or more predicts 3x difficulty • Approximately 1 in 500 fails 4/24/2008 Difficult Airway • Predicting difficult BVM – High BMI – Advanced age – Beards – Lack of teeth 4/24/2008 Difficult Airway • Awake Fiberoptic intubation 4/24/2008 Difficult Airway • LMA 4/24/2008 LMA Insertion 4/24/2008 Difficult Airway • Lighted Stylet 4/24/2008 Difficult Airway • Gum Elastic Bougie 4/24/2008 Difficult Airway • Retrograde Intubation 4/24/2008 Difficult Airway • Digital Intubation 4/24/2008