ICU Emergency AIRWAY MANAGEMENT

Dalhousie Critical Care Lecture Series

Introduction

• Case history• Airway assessment• Sedation the KISS approach• Ventilation vs. Intubation• Airway adjuncts• Education

Case History

• 56 y.o. male morbidly obese (BMI=38) with CAP.

• Gradual deterioration over 12 hours

• Failed non-invasive ventilation• On 100% O2 with O2 sats of 78% and RR of 40 obtunded BP 70/40

• Now what?

Airway Anatomy….

Airway Exam

• Mallampatti Score

Airway Exam• Thyromental Distance• (6cm / 3 FB)

• Jaw Subluxation

• Mouth Opening (3 FB)

• Atlanto-Occipital Extension (30 degrees)

Airway Anatomy….

Airway Exam

• Check old anesthetic records (remember Star Trek)

• IV Access unless in extremis (place tube)

• Sedation if necessary

Cormack-Lehane Laryngeal View

Definition Minimal Sedation -Anxiolysis

Conscious sedation is the use of medication to minimally depress the LOC in a patient while allowing the patient to continually and independently maintain a patent A/W and respond appropriately to verbal commands or gentle stimulation.

Chet Wyman, University of Maryland School of Medicine

Sedatives In The Ideal World

• Safe• Painless route of administration• Rapid predictable onset• Predictable duration• Reversible• Absence of cardio/respiratory/CNS depression

There are no drugs available which achieve these ideals!

Midazolam (Versed®)

•Short acting benzodiazepine

•used for sedation, anxiolysis, and amnesia

•also used as an induction agent for GA and as an adjunct to regional anesthesia.

Midazolam

Onset: 1-3 minutes

Peak Effect: 3-5 minutes

Duration of action: 45-60 minutes

Adverse reactions: Respiratory depression especially with opioids.

•Minimal hemodynamic effects

• Antagonist: Flumazenil

Fentanyl

•It is a synthetic opioid

•100 times more potent than morphine

•Mu1 receptors produce analgesia and physical dependence

•Mu2 receptors produce respiratory depression, nausea, vomiting, constipation and bradycardia

Fentanyl

•Onset: Immediate response

•Duration of action: < 60 minutes

•Half life: 2-4 hrs.

•Increased risk of respiratory depression when given with Benzodiazepines

•Antagonist: Naloxone

Etomidate

• 0.3 mg/kg, with a time to effect of 15 to 45 seconds

• duration of action of 3 to 12 minutes • most hemodynamically neutral of the sedative agents used for RSI

• The hemodynamic stability associated with etomidate makes it the drug of choice for the intubation of hypotensive patients, as well as an attractive option for patients with intracranial pathology, when hypotension must be avoided

Etomidate

• Some researchers have raised concerns regarding the safety of etomidate in the setting of adrenal insufficiency– Adrenal insufficiency in meningococcal sepsis: bioavailable cortisol levels and impact

of interleukin-6 levels and intubation with etomidate on adrenal function and mortality. AUden Brinker M; Joosten KF; Liem O; de Jong FH; Hop WC; Hazelzet JA; van Dijk M; Hokken-Koelega AC SOJ Clin Endocrinol Metab. 2005 Sep;90(9):5110-7. Epub 2005 Jun 28.

– Should we use etomidate as an induction agent for endotracheal intubation in patients with septic shock?: a critical appraisal. AUJackson WL Jr SOChest 2005 Mar;127(3):1031-8.

– Risk factors of relative adrenocortical deficiency in intensive care patients needing mechanical ventilation. Care Med 2005 Mar;31(3):388-392.  

• When intubating the critically ill patient with possible adrenal insufficiency, the clinician must weigh the relative risk of cortisol suppression against the hemodynamic instability that may be caused by other induction agents

Topical Anesthesia

Each spray = 10 mg of lidocaine Maximum dose = 5 mg/kgi.e. for 70 kg patient =35 sprays!

3 sprays of lidocaine to each location + 3 sprays behind tongue

Airway Management

4 Questions

1. Can I oxygenate this patient with a BVM?

2. Can I ventilate with a supra-glottic device (SGD) i.e. LMA?

3. Can I place a tube in the trachea?

4. Can I secure a surgical airway?

Murphy et al CJA 2005 52:3

Basic Airway Management

• Head tilt/chin lift

• Jaw thrust

• Mandibular

displacement

OPA

• Oropharyngeal Airway

– What size ?

– Contraindications ?

NPA

• Nasopharyngeal airway

– What size ?– Contraindications ?

Mask Ventilation Requires…

• Patent airway

• Proper fitting mask

• Good technique

• OPA/NPA

• PPV/Oxygen

2 Handed BVM

Difficult Ventilation

• MOANSM = difficult mask seal (full beard)

O = obese or airway obstruction

A = advanced ageN = no teethS = snore or stiff lungs

Hung and Murphy CJA 2004 51:10

Can I ventilate this patient ??•Beard

•Obese•Old•Teeth •Sleep apnea

Predictors of Difficult Intubation

• Small TM distance-beware the beard

• Poor mouth opening• High Mallampati score

• 84.9% sensitivity• 94.6% specificity• 35.5% PPV

Merah NA et al CJA 2005 52

Can’t Intubate/Can’t Ventilate

or Holy *@#& Phenomenon• Failed laryngoscopic intubations (0.05-0.35%)

• Can’t intubate/can’t ventilate (1:2250)

Benumof JL Airway Management Principles and Practice1996:124.

Time to intubate . . .

• Basic Equipment– PPV (BVM ventilation)– Oxygen– ETT– Suction– Laryngoscope– Bougie– LMA

Position Your Patient

• Sniffing Position• Flexion of lower cervical spine

• Extension of A-O joint

What Size Endotracheal Tube ?

• Adult male• 7.5-8.5

• Adult female• 6.5-7.5

• Pediatric• 4 + AGE/4

What Laryngoscope ?

Laryngoscopy

Intubation Confirmation !• Bronchoscopy, direct

visualization, carbon dioxide• Auscultation, compliance, condensation, chest wall excursion

• CXR

Airway Adjuncts

Cricoid Pressure

• New data suggests it is better to position larynx with right hand and then demonstrate position

• BURP larynx posterior, up and to the patient’s right

• C/I in c-spine fracture

Laryngeal Mask Airway

• Indication– Alternate to BMV– Difficult airway scenario

• Contraindications – Obese– Reflux– Full stomach

Bougie

• Tracheal “clicks”

• End point

• Right turn

Special Cases

• Obesity

• Rheumatoid arthritis

• Head and neck cancer

• Trauma/Fractured c-spine

Obesity• Redundant tissue in oropharynx•Thoracic kyphosis FRC•Minimal apnea time• i.e. rapid desaturation

Positioning Obese Patients

The blue axis =ear to manubriumshould be level

Rheumatoid Arthritis

• Multisystem disease

• C1-C2 subluxation > 5mm clinical significant

• Arytenoid disease

• Restrictive lung disease

C1 and C2 Anatomy

Head and Neck Cancer

• Previous surgery and/or radiotherapy

• Tissues are “woody” immobile

• Supraglottic masses unable to see glottis impossible DL

• Or previous laryngectomy and No glottis!

• Consider bronchscopy

Head and neck masses

Epiglottis

Glottic opening

Supraglottic mass

C-spine Trauma

•Head Injury common

•In-line stabilization essential

•Maintain oxygenation and BP

In-line Stabilization

What about the Patient with Pneumonia?

• How would you manage this scenario?

Answer

• This is an emergency situation, Call for HELP

• Confirm patient is on 100% O2 !• Take a brief history including drugs (sedatives)

• Examine airway for ease of Ventilation and Intubation

• Assist ventilation, 2 handed BVM + OPA• Recheck vitals• Position patient for airway management• Do not make patient APNEIC