Airway Management in the Emergency Department and ICU

1
Airway Management in the Emergency Department
and ICU

• Mehdi Khosravi, MD Pulmonary/CCM Fellow
• Giuditta Angelini, MD Assistant Professor
• Jonathan T. Ketzler, MD Associate Professor
• Douglas B. Coursin, MD Professor
• Departments of Anesthesiology Medicine
• University of Wisconsin, Madison

2
Global Assessment

• Assess underlying need for airway control
• Duration of intubation
• - Nasal intubation less advantageous for
  potentially prolonged ventilator requirements
• Permanent support
• - Underlying advanced intrinsic lung or
  neuromuscular disease
• Temporary support
• Anesthesia
• Presence of reversible intrinsic lung or
  neuromuscular disease
• Protection of the airway due to depressed mental
  status
• Presence of reversible upper airway pathology
• Patient care needs (e.g., transport, CT scan,
  etc.)
• Significant comorbidities
• Aspiration potential or increased respiratory
  secretions
• Hemodynamic issues such as cardiac disease or
  sepsis
• Renal or liver failure

3
Global Assessment

• Pathophysiology of the respiratory failure
• Hypoxic respiratory failure
• - In case of hypoxic respiratory failure,
  different noninvasive oxygen delivery devices can
  be used.
• - The severity of hypoxia and presence or absence
  of underlying disease (such as COPD) will dictate
  the device of choice.
• Hypercapnic respiratory failure
• - The noninvasive device of choice for
  hypercapnic respiratory failure is BIPAP.
• Assessment of above mentioned patient
  characteristics in conjunction with the mechanism
  of respiratory distress leads the clinician to
  proper choice and duration of invasive or
  noninvasive options for airway management.
• Code status should be clarified prior to
  proceeding.

4
Global Assessment

• Oxygenation
• Respiratory rate and use of accessory muscles
• - Is the patient in respiratory distress?
• Amount of supplemental oxygen
• - What is the patients oxygen demand?
• Pulse oximeter or arterial blood gas
• - Is the patient physiologically capable of
  providing appropriate supply?
• Airway
• Anatomy
• - Will this patient be difficult to intubate?
• Patency
• - Is there a reversible anatomical cause of
  respiratory failure as opposed to intrinsic lung
  dysfunction?
• Airway device in place
• - Is there a nasopharyngeal airway or combitube
  in place?

5
Oxygen Delivery Devices(In order of degree of
support)

• Nasal Cannula
• 4 increase in FiO2 for each 1 L of flow (e.g., 4
  L flow 37 or 6 L flow 45)
• Face tent
• At most delivers 40 at 10-15 L flow
• Ventimask
• Small amount of rebreathing
• 8 L flow 40, 15 L flow 60
• Nonrebreather mask
• Attached reservoir bag allows 100 oxygen to
  enter mask with inlet/outlet ports to allow
  exhalation to escape - does not guarantee 100
  delivery.

6
Oxygen Delivery DevicesNoninvasive Positive
Pressure

• CPAP is a continuous positive pressure
• Indicated in hypoxic respiratory failure and
  obstructive sleep apnea
• BiPAP allows for an inspiratory and expiratory
  pressure to support and improve spontaneous
  ventilation
• Mainly indicated in hypercapnic respiratory
  failure and obstructive sleep apnea
• If use of noninvasive modes of ventilation does
  not result in improved ventilation or oxygenation
  in two to three hours, intubation should be
  considered
• These devices can be used if following conditions
  are met
• Patient is cooperative with appropriate level of
  consciousness
• Patient does not have increased respiratory
  secretions or aspiration potential
• Concurrent enteral feeding is contraindicated.
• Facilitates early extubation, especially in COPD
  patients
• Some devices allow respiratory rate to be set.
• Up to 10 L of oxygen can be delivered into the
  mask for 100 oxygen delivery.

7
Degree of Respiratory Distress

• Respiratory pattern
• Accessory muscle use is an indication of
  distress.
• Rate gt 30 can indicate need for more support by
  noninvasive positive pressure or intubation
• Need for artificial airway
• Tongue and epiglottis fall back against posterior
  pharyngeal wall
• Nasopharyngeal airway better tolerated
• Pulse oximetry
• O2 saturation less than 92 on 60 - 100 oxygen
  can suggest the need for intubation based on
  whether there is anything immediately reversible
  which could improve ventilation.
• Arterial blood gas
• pH lt 7.3 can indicate need for more support by
  noninvasive positive pressure or intubation.

8
Temporizing Measures

• Naloxone for narcotic overdose
• 40 mcg every minute up to 200 mcg with
• - 45 minutes to one hour duration of action
• 0.4 - 2 mg of naloxone is indicated in patients
  with respiratory arrest and history suggestive of
  narcotic overdose
• - There is a potential for pulmonary edema, so
  large dose is reserved for known overdose and
  respiratory arrest
• Caution in patients with history of narcotic
  dependence
• Naloxone drip can be titrated starting at half
  the bolus dose used to obtain an effect
• - Manufacturer recommended 2 mg in 500 ml of
  normal saline or D5 gives 0.004 mg/ml
  concentration

9
Temporizing Measures (cont'd)

• Flumazenil for benzodiazepine overdose
• 0.2 mg every minute up to 1 mg
• Caution in patients with history of
  benzodiazepine or alcohol dependence
• Caution in patients with history of seizure
  disorder as it will decrease the seizure
  threshold
• Artificial airway for upper airway obstruction in
  patients with oversedation
• May be necessary in patients with sleep apnea
  despite judicious sedation
• 100 oxygen and maintenance of spontaneous
  ventilation in patients with pneumothorax
• Washout of nitrogen may decrease size of
  pneumothorax
• Positive pressure may cause conversion to tension
  pneumothorax

10
Oral/Nasal Airways
11
Indications for Intubation

• Depressed mental status
• Head trauma patients with GCS 8 or less is an
  indication for intubation
• - Associated with increased intracranial pressure
• - Associated with need for operative intervention
• - Avoid hypoxemia and hypercarbia which can
  increase morbidity and mortality
• Drug overdose patients may require 24 - 48 hours
  airway control.
• Upper airway edema
• Inhalation injuries
• Ludwigs angina
• Epiglottitis

12
Underlying Lung Disease

• Chronic obstructive lung disease
• Application of controlled ventilation may
  interfere with complete exhalation, overdistend
  alveoli, and impair right heart and pulmonary
  venous return.
• Pulmonary embolus
• Pulmonary artery and right ventricle already have
  high pressure and dependent on preload
• Application of controlled ventilation may
  deteriorate oxygenation and systemic pressure.
• Restrictive lung disease
• May require less than 6 cc/kg Vt to prevent
  elevated intrapulmonary pressure
• Application of positive pressure may result in
  barotrauma in addition to impaired preload.

13
Airway Anatomy Suggesting Difficult Intubation

• Length of upper incisors and overriding maxillary
  teeth
• Interincisor (between front teeth) distance lt 3
  cm (two finger tips)
• Thyromental distance lt 7 cm
• tip of mandible to hyoid bone (three finger
  breaths)
• Neck extension lt 35 degrees
• Sternomental distance lt 12.5 cm
• With the head fully extended and mouth closed
• Narrow palate (less than three finger breaths)
• Mallampati score class III or IV
• Stiff joint syndrome
• About one third of diabetics characterized by
  short stature, joint rigidity, and tight waxy
  skin
• Positive prayer sign with an inability to oppose
  fingers

Prayer Sign
Erden V, et al. Brit J Anesth. 200391159-160.
14
Mallampati Score

• Class I Uvula/tonsillar pillars visible
• Class II Tip of uvula/pillars hidden by tongue
• Class III Only soft palate visible
• Class IV Only hard palate visible

Den Herder, et al. Laryngoscope.
2005115(4)735-739.
15
Comorbidities

• Potential for aspiration requires rapid sequence
  intubation with cricoid pressure
• Clear liquids lt 4 hours
• Particulate or solids lt 8 hours
• Acute injury with sympathetic stimulation and
  diabetics may have prolonged gastric emptying
  time.
• Potential for hypotension
• Cardiac dysfunction, hypovolemia, and sepsis
• May need to consider awake intubation with
  topical anesthesia (aerosolized lidocaine) as
  sedation may precipitate hemodynamic compromise
  and even arrest.
• Organ failure
• Renal and hepatic failure will limit medication
  used.
• Potential for preexisting pulmonary edema and
  airway bleeding from manipulation

16
Induction Agents

• Sodium Thiopental
• 3 - 5 mg/kg IV
• Profound hypotension in patients with
  hypovolemia, histamine release, arteritis
• Dose should be decreased in both renal and
  hepatic failure.
• Etomidate
• 0.1 - 0.3 mg/kg IV
• Lower dose range for elderly and hypovolemic
  patients
• Hemodynamic stability, myoclonus
• Caution should be exercised as even one dose
  causes adrenal suppression due to similar steroid
  hormone structure.
• Unlikely to have prolonged effect in organ failure

17
Induction Agents (cont'd)

• Propofol
• 2 - 3 mg/kg IV
• Hypotension, especially in patients with systolic
  heart dysfunction, bradycardia, and even heart
  block
• Unlikely to have prolonged effect in organ
  failure
• Ketamine
• 1 - 4 mg/kg IV, 5 - 10 mg/kg IM
• Stimulates sympathetic nervous system
• Requires atropine due to stimulated salivation
  and midazolam for potential of dysphoria
• Avoid in patients with loss of autoregulation and
  closed head injury

18
Neuromuscular Blockers

• Succinylcholine
• 1 - 2 mg/kg IV, 4 mg/kg IM
• Avoid in patients with malignant hyperthermia, gt
  24 hours out from burn or trauma injury, upper
  motor neuron injury, and preexisting hyperkalemia
• Rocuronium
• 0.6 - 1.2 mg/kg, highest dose required for rapid
  sequence
• Hemodynamically stable, 10 renal elimination
• Vecuronium
• 0.1 mg/kg
• Hemodynamically stable, 10 renal elimination
• Cisatricurium
• 0.2 mg/kg
• Mild histamine release, Hoffman degradation, not
  prolonged in renal or hepatic failure

19
Rapid Sequence Intubation

• Preoxygenate for three to five minutes prior to
  induction
• Wash out nitrogen to avoid premature desaturation
  during intubation.
• Crycoid pressure should be applied from prior to
  induction until confirmation of appropriate
  placement.
• Succinylcholine 1 - 2 mg/kg IV will achieve
  intubation conditions in 30 seconds Rocuronium
  1.2 mg/kg IV will achieve intubation conditions
  in 45 seconds.
• Other muscle relaxants do not produce intubation
  conditions in less than 60 seconds.
• Avoid mask ventilation after induction.
• Potentially can inflate stomach
• Use only if necessary to ensure appropriate
  oxygenation during prolonged intubation.

20
Y BAG PEOPLE (Reference 6)
21
Cricoid Pressure

• Cricoid is circumferential cartilage
• Pressure obstructs esophagus to prevent escape of
  gastric contents
• Maintains airway patency

Koziol C, et al. AORN. 200072(6)1018-1030.
22
Sniffing Position
Align oral, pharyngeal, and laryngeal axes
to bring epiglottis and vocal cords into view.
Hirsch N, et al. Anesthesiology. 200093(5)1366.
23
Mask Ventilation

• Mask ventilation crucial, especially in patients
  who are difficult to intubate
• Sniffing position with tight mask fit optimal
• May require two hands
• Mask ventilation crucial, especially in patients
  who are difficult to intubate
• Sniffing position with tight mask fit optimal
• May require two hands

24
Laryngoscope Blades and Endotracheal Tubes
Mac blade End of blade should be placed in front
of epiglottis in valecula
ETT for Fastrach LMA
Pediatric uncuffed ETT
ETT for blind nasal
Standard ETT
Miller blade End of blade should be under
epiglottis
25
Graded Views on Intubation
Grade 1 Full glottis visible Grade 2 Only
posterior commissure Grade 3 Only
epiglottis Grade 4 No glottis structures are
visible
Yarnamoto K, et al. Anesthesiology.
199786(2)316.
26
Confirmation of Placement

• Direct visualization
• Humidity fogging the endotracheal tube
• End tidal CO2 which is maintained after gt 5
  breaths
• Low cardiac output results in decreased delivery
  of CO2
• Refill in 5 seconds of self-inflating bulb at the
  end of the endotracheal tube
• Symmetrical chest wall movement
• Bilateral breath sounds
• Maintenance of oxygenation by pulse oximetry
• Absence of epigastric auscultation during
  ventilation

27
Additional Considerations

• Always have additional personnel and an
  experienced provider as backup available for
  potential failed intubation
• Always have suction available
• Never give a muscle relaxant if difficult mask
  ventilation is demonstrated or expected
• Awake intubation should be considered in the
  following
• If patient is so hemodynamically unstable that
  induction drugs cannot be tolerated (topicalize
  airway)
• If patient has a history or an exam which
  suggests difficult mask ventilation and/or direct
  laryngoscopy

28
American Society of Anesthesiologists www.asahq.or
g
29
Alternative Methods

• Blind nasal intubation
• Bleeding may cause problems with subsequent
  attempts.
• Contraindicated in patients with facial trauma
  due to cribiform plate disruption or CSF leak
• Avoid in immune suppressed (i.e., bone marrow
  transplant)
• Eschmann stylet
• Fiber optic bronchoscopic intubation
• Awake vs. asleep
• Laryngeal mask airway
• Allows ventilation while bridging to more
  definitive airway
• Light wand
• Retrograde intubation
• Through cricothyrotomy
• Surgical tracheostomy
• Combitube

30
Eschman Stylet

• Use especially if Grade III view achieved
• Direct laryngoscopy is performed
• Place Eschman where trachea is anticipated
• May feel tracheal rings against stiffness of
  stylet
• Thread 7.0 or 7.5 ETT over stylet with the
  laryngoscope still in place

31
Fiberoptic Scope

• Essentially what is used to do a bronchoscopy
• Can be used to thread an endotracheal tube into
  the trachea either while the patient is asleep or
  on an awake patient with a topicalized airway
• Via laryngeal mask airway in place due to
  inability to intubate with DL
• Aintree (airway exchange catheter) can be
  threaded over the FOB to be placed into trachea
  upon visualization
• Wire-guided airway exchange catheter can also be
  used with one more step

32
The Laryngeal Mask Airway (LMA)
33
LMA Placement

• Guide the LMA along the palate
• Eventual position should be underneath the
  epiglottis, in front of the tracheal opening,
  with the tip in the esophagus
• FOB placement through LMA positions in front of
  trachea

Martin S, et al. J Trauma Injury, Infection Crit
Care. 199947(2)352-357.
34
The FastrachTM Laryngeal Mask Airway

• Reinforced LMA allows for passage of ETT without
  visualization of trachea.
• 10 failure rate in experienced hands
• 20 failure rate in inexperienced

35
The Light Wand

• Transillumination of trachea with light at distal
  end
• Trachea not visualized directly
• Should not be used with tumors, trauma, or
  foreign bodies of upper airway
• Minimal complication except for mucosal bleed
• 10 failure rate on first attempt in experienced
  hands

36
Retrograde Intubation

• Puncture of the cricothyroid membrane with
  retrograde passage of a wire to the trachea
• Endotracheal tube guided endoscopically over the
  wire through the trachea
• Catheter through the cricothyroid can be used for
  jet ventilation if necessary.

Wesler N, et al. Acta Anaes Scan.
200448(4)412-416.
37
Combitube

• Emergency airway used mostly by paramedics and
  emergency physicians for failed endotracheal
  intubation
• Ventilation confirmed through blind blue tube
• Combitube is in the esophagus and salem sump can
  be placed through white tube
• Ventilation confirmed through white (clear) tube
  with patent distal end
• Combitube is in the trachea and salem sump should
  be placed outside of combitube into esophagus
• Fiber optic exchange can be accomplished through
  combitube

38
Combitube (cont'd)

• Should be changed to endotracheal tube (ETT) or
  tracheostomy to prevent progressive airway edema
• If in esophagus, take down pharyngeal cuff and
  attempt direct laryngoscopy (DL) or fiber optic
  bronchoscope (FOB) placement around combitube
• Failed exchange attempt can be solved with
  operative tracheostomy
• Placement of combitube can produce significant
  airway trauma
• Removal prior to DL or FOB should be done with
  caution after thorough airway evaluation
• Cricoid pressure should be maintained and
  emergency tracheostomy equipment available

39
Tracheostomy

• Surgical airway through the cervical trachea
• Emergent procedure carries risk of bleeding due
  to proximity of innominate artery
• Can be difficult and time consuming in emergent
  situations

Sharpe M, et al. Laryngoscope. 2003113(3)530-536
.
40
Case Scenario 1

• The patient is 70 kg with a 20-year history of
  diabetes.
• On exam, the patient has intercisor distance of 4
  cm, thyromental distance is 8 cm, neck extension
  is 45 degrees, and mallampati score is 1.
• Your staff wants to use thiopental and
  pancuronium.
• Do you have any further questions for this
  patient or would you proceed with your staff?

41
Case Scenario 1 - Answer

• A diabetic for 20 years needs assessment for
  stiff joint syndrome.
• You should have the patient demonstrate the
  prayer sign.
• If the patient is unable to oppose their fingers,
  you should not give pancuronium.
• You may want to proceed with an LMA and FOB at
  your disposal.
• If the patient has a history of gastroparesis,
  you may want to consider an awake FOB.

42
Case Scenario 2

• 43-year-old patient with HIV, likely PCP
  pneumonia who had been prophylaxed with dapsone
• RR is 38, oxygen saturation is 90 on 100 NRB
  mask
• The patient is on his way to get a CT scan.
• Is it appropriate to proceed without intubation?

43
Case Scenario 2 - Answer

• Dapsone will produce some degree of
  methemoglobinemia.
• Therefore, some degree of desaturation may not be
  overcome.
• The patient is in significant respiratory
  distress and will be confined in an area without
  easy access.
• Intubation should be considered as an extra
  measure of safety, especially as this patient is
  likely to get worse.

44
Case Scenario 3

• 40-year-old, 182-kg man has a history of sleep
  apnea and systolic ejection fraction of 25. He
  has a Strep pneumonia in his left lower lobe and
  progressive respiratory insufficiency.
• He extends his neck to 50 degrees and has a
  mallampati score of 2.
• Would you proceed with an awake FOB?

45
Case Scenario 3 - Answer

• The patients airway anatomy is not suggestive of
  difficulty.
• However, with supine position, subcutaneous
  tissue may impair your ability to visualize or
  ventilate.
• Use of gravity, including a shoulder roll,
  extreme sniffing position, and reverse
  trendelenburg may be helpful with asleep DL.
• Prudent to have some accessory equipment,
  including an LMA and FOB, for back up

46
References

• Caplan RA, et al. Practice guidelines for
  management of the difficult airway.
  Anesthesiology. 199378597-602.
• Langeron O, et al. Predictors of difficult mask
  ventilation. Anesthesiology. 2000921229-36.
• Frerk CM, et al. Predicting difficult intubation.
  Anaesthesia. 1991461005-08.
• Tse JC, et al. Predicting difficult endotracheal
  intubation in surgical patients scheduled for
  general anesthesia. Anesthesia Analgesia.
  199581254-8.
• Benumof JL, et al. LMA and the ASA difficult
  airway algorithm. Anesthesiology. 199684686-99.
• Reynolds S, Heffner J. Airway management of the
  critically ill patient. Chest. 20051271397-1412.