Transcript www.hkcem.com

HKCEM College Tutorial
Airway
Management
in a Comatose
patient
AUTHOR
DR. LAM PUI KIN, REX
OCT 2013
Objectives
1. Recognise indications for intubation
2. Anticipate difficult airway
3. Preparation for RSI
4. Procedure of RSI
5. How to handle if you fail to intubate
Triage
▪ M/34
▪ presented to ED 2 hours post-ingestion of 20
tablets of psychiatric drug
▪ GCS 8
▪ BP 149/91 P146
▪ RR 20/min
▪ Temp 37.3°C
Triage Category I
How would you manage him?
START WITH ABC
How would you manage his airway?
Indications for intubation
▪ Protection of airway
▪ GCS only 8
▪ Lavage may be needed
▪ Prevent aspiration
Other general indications for
intubating a patient
▪ Other common indications
▪ Airway obstruction
▪ Respiratory Failure
▪ Adjuncts to therapy
▪ Provide hyperventilation
▪ Reduce work of breathing (e.g.
decompensated shock)
▪ Situational need
Why rapid sequence intubation (RSI) ?
▪ Rapidly create controlled clinical
environment for ETI
▪ Reduce stimulation of potentially harmful
autonomic reflexes associated with ETI
▪ Reduce risk of aspiration
Any absolute contraindication?
No … However
Relative contraindications to RSI
▪ Operator concern that both intubation and mask
ventilation may not be successful
▪ Major laryngeal trauma
▪ Upper airway obstruction
▪ Distorted facial or airway anatomy
predict difficult airway before initiation of paralytic
agent to prevent the situation of cannot ventilate
and cannot intubate (CVCI)
Clinical Assessment before RSI
▪ AMPLE history:
Allergies
Medication
Past history
Last meal
Event- trauma, increased ICP, asthma
▪ Neurological assessment before RSI
LEMON LAW
▪ Look externally
▪ Evaluate the 3-3-2 rule
▪ Mallampati score
▪ Obstruction
▪ Neck mobility
MOANS – mnemonic for difficult BVM
▪ Mask seal
beards, facial trauma
▪ Obesity/obstruction
BMI > 26, airway obstruction,
obstetric patients
▪ Age
> 55 yrs
▪ No teeth
▪ Stiffness
Increase airway resistance
(asthma, COPD), stiff lungs
(pulmonary edema)
RSI is decided for this patient
How do you prepare for RSI?
Personnel
Equipment
Drugs
Personnel
▪ A team effort
▪ Junior doctor should be covered by a senior who is
well versed in RSI
▪ Help from an on-call anesthetist should be
available when needed
Equipment – LAST SOB
▪L
Laryngoscope
▪A
Airway
▪S
Suction
▪T
Tracheal tube
▪S
Stylet, syringe
▪O
Oxygen, Oximeter
▪B
Bag, eosphageal bulb, bougie
Not to forget!
Full PPE in
high risk cases
Do you know where is the
difficult airway kit in
your ED ?
Do you know what is
inside?
Drugs
▪ Premedications
▪ prevent bradycardia
▪ prevent raised ICP
▪ prevent bronchospasm
▪ Induction agent
▪ Muscle relaxant
▪ Consider sedation and long acting muscle relaxant after
RSI
Now, take us through the steps of RSI.
The Seven Ps of RSI
▪ Preparation
zero minus 10 min
▪ Pre-oxygenation
zero minus 5 min
▪ Premedication
zero minus 3 min
▪ Paralysis with induction
zero
▪ Protection and position
20 to 30 seconds (after
succinylcholine)
▪ Placement with proof
45 seconds (after
succinylcholine)
▪ Post-intubation management
1 min
How do you pre-oxygenate?
▪ IPPV?
▪ Any problems?
IPPV will blow up stomach and increase risk
of aspiration. If time allows, spontaneous
respiration is better.
Pre Oxygenation + Monitoring
▪ to wash out nitrogen from lung
▪ High conc O2 mask (near 100%) x 5
minutes (SR)
▪ Near 100% O2 x 4 max breath over
30 s (IPPV)
▪ especially important in patient with
 FRC
▪ obese
▪ distended abd
▪ pregnancy
Benumof JL et al. Anesthesiology 1997;87:979
Premedication – “LOAD”
Lignocaine
1 - 1.5mg/kg
▪ Mitigate bronchospasm in severe asthma
▪ Blunt ICP rise
▪ Controversial
Opioids - Fentanyl
1-2 mcg/kg
▪ Blunt sympathetic discharge and ICP rise
▪ E.g. raised ICP, aortic dissection, ruptured aortic aneursym, IHD
Premedication – “LOAD”
Atropine 0.02 mg/kg (min 0.1mg)
▪ To prevent bradycardia (sux used in a child)
Defasciculation (rarely done in ED)
▪ Non-depolarising relaxant
▪ 1/10 of paralysing dose
What induction agent would you use?
▪ Why?
▪ Dosage?
▪ Adverse effects?
Induction Agents
Drug
Dose
Midazolam
Thiopentone
Ketamine
Onset
Duration
Remarks
0.2 - 0.3 mg/kg 2-3 min
3 - 5 mg/kg
30 sec
1 - 2 mg/kg
30 – 60 sec
20 – 30 min
10 - 15 min
10 – 15 min
Hypotension
Hypotension
Bronchodilator
Increase ICP
and salivation
Emergence
phenomenon
Etomidate
0.2 – 0.3
mg/kg
30 – 60 sec
10 – 15 min
Adrenal
suppression
Stable CVS
Propofol
2 – 2.5 mg/kg
30 – 60 sec
3 – 5 min
Apnoea,
hypotension
How do you perform cricoid
pressure?
Cricoid pressure
▪ Prevent aspiration of
stomach content
▪ also prevent insufflation of
stomach if IPPV is needed
▪ Apply till ETT position
confirmed
Cricoid pressure
▪ Around 10 pounds of force
over cricoid cartilage
▪ force enough to
▪ stop swallowing
▪ indent a ping-pong
▪ cause pain over nose bridge
Which muscle relaxant to use?
▪ Why?
▪ Dosage?
▪ Adverse effects?
Muscle relaxants
Drug
Succinylcholine
Dose
1 – 2 mg/kg
Onset
30 – 60 sec
Vecuronium
Pancuronium
0.1 – 0.3 mg/ kg 60 -90 sec
0.08 – 0.1 mg/ kg 3 – 5 min
20 – 40 min
80 – 100 min
Rocuronium
0.6 – 0.9 mg/kg
30 – 45 min
40 – 60 sec
Duration
4 – 10 min
Remark
Increase ICP,
IOP, IGP,
hyperkalemia,
bradycarida
CVS stable
Loner acting,
tachycardia
CVS stable
What are the side effects of sux?
Side effects of sux
▪ CVS
▪ bradycardia, junctional, sinus arrest
▪ tachycardia (gangionic stimulation)
▪ Increase in ICP, IOP, IGP
▪ Trismus (patient with myoclonus)
▪ Myalgia
▪ Histamine release
Side effects of sux
▪ Hyperkalemia
▪ normal increase 0.5 mmol/L
▪ massive release in
▪ burn (day 3 till to 1 yr after healing)
▪ massive trauma (day 3 to 3 months)
▪ neuromuscular-disorders: CVA, cord injury, tetanus (day 5 - 6
months)
▪ muscular dystrophy
▪ Malignant hyperthermia
Sux-- Phase II block
▪ Prolonged NMB resembling those of nondepolarising agents
▪ Occurs with intermittent/infusion of sux
▪ Lower pseudocholinesterase level
▪ Hepatic dx, uremia, severe malnutrition, pregnancy,
congenital
▪ Myasthenia gravis
▪ partially reversed by anticholinesterase
How to assist the intubator in
visualization of cord?
OELM vs BURP
(optimal external laryngeal manipulation)
(backward upward rightward pressure)
▪ O ptimal
▪ B ackward
▪ E xternal
▪ U pward
▪ L aryngeal
▪ R ight ward
▪ M anipulation
▪ P ressure
▪ Operator manipulates and
obtains view of larynx, then asks
assistant to hold
▪ Assistant performs BURP for
operator
Cormack-Lehane system
How do you confirm tube position?
PRIMARY
SECONDARY
Confirming Tube Position
Esophageal Intubation
(EDD)
▪ Aspiration test
▪ Self-inflating bulb
▪ ETCO2
Monitor patient
▪ Make sure tube is fixed
securely
▪ monitor patient
▪ pulse oximeter
▪ end tidal CO2
▪ BP/P
Look at this CXR
What is the
problem?
Remember DOPE
when anything goes
wrong
Right Main Bronchus Intubation
Post-intubation management
▪ Bite block
▪ Maintenance of sedation and NMB
▪ Midazolam 0.05 – 0.1 mg/kg IV per dose, titrated
▪ Recuronium 0.6 mg/kg IV of vecuronium 0.1
mg/kg IV as
▪ Beaware of under-sedation with concomitant use
of NMB
▪ Consider titrating dose of morphine 0.025-0.05
mg/kg
▪ Continuous monitoring
▪ Reassess tube position after transfer
What if you fail to intubate?
▪ Reoxygenate should take priority over repeated DL attempts
▪ Ventilate with BVM
▪ Evaluate cause of failure
▪ Positioning? Equipment? Inadequate muscle relaxation? etc
▪ Call for help from seniors +/- anaesthetist
▪ Consider alternatives (Plan B & C)
▪ Consider needle & surgical cricothyroidotomy
Repositioning
Gum Elastic Bougie
McCoy Laryngoscope
Supraglottic devices
LMA
Intubating LMA
Combitube
King airway
Videolaryngoscopes
Glidescope
ASA Airway Management Guidelines
Summary
We have covered:
1. Indications for intubation
2. How to assess difficult airway
3. How to perform RSI
4. How to handle if you fail to intubate
The end