S4C30 - Tracheal Intubation and Mechanical Ventilation Flashcards
1
Q
Equiptment
A
- ETT: 7.5 women and 8 men
- blade:
- Macintosh #3 or #4 if large
- Miller #2 or #3 if large pt
2
Q
Intubation: Patient positioning
A
- sniffing position
- flexion of lower neck with extension at the atlanto-occipital joint
3
Q
Intubation: ETT insertion
A
- use BURP
- ensure cuff of the ETT is pushed completely past the cords
- if unable to see cords/larynx, try bougie
- if using a stylet, try to use an angle <35 degrees
- if difficulty passing the ETT, try using a smaller size
- inflate ETT cuff with 5cc of air
4
Q
Capnometers/Capnography
A
- colorimetric:
- will turn from purple to yellow if exposed to Pco2 >15 (15-38), will not turn yellow if Pco2 <4mmHg
- capnography:
- displays CO2 waveforms
- false negative reading will occur if: cardiac arrest or massive PE (low pulmonary perfusion), massive obesity, severe pulmonary edema
- false positive reading: recent ingestion of carbonated beverage (will clear w/in 6 breaths), nebulized epinephrine (transient)
5
Q
Intubation: complications
A
- tube can become dislodged
- may intubate a mainstem bronchus
- tube may become obstructed from thrombus or secretions
6
Q
RSI
A
- pre-treatment agents should be given 3-5mins before RSI
- lidocaine - for elevated ICP, bronchospasm (limited evidence for this)
- fentanyl - elevated ICP, cardiac ischemia, Ao diss.
- good for pts whom you are worried about a reflex sympathetic response to airway manipulation
- atropine - children <5yo with symptomatic bradycardia
- induction agents:
- etomidate 0.3mg/kg - maintains stable hemodynamics, decreases ICP and IOP
- SE: myocolic jerking, decrease cortisol, no analgesia
- propofol 0.5-1.5mg/kg - antiemetic, anticonvulsant, decreases ICP
- SE: causes apnea, decreased BP, no analgesia
- ketamine 1-2mg/kg - bronchodilator, no apnea, provides analgesia
- SE: increased secretions, increased BP, emergence
- paralytic agents
- depolarizing agents: affinity for cholinergic receptors and resistant to acetylcholinesterase, produce fasciculations then paralysis
- eg. succinylcholine
- nondepolarizing agents compete with acetylcholine for the cholinergic receptors - can be antagonized by anticholinesterase agents
- eg. rocuronium, pancuronium, vecuronium
7
Q
RSI: paralytic agents
A
-succinylcholine
- relaxation by 60s and complete paralysis by 2 mins, off by ~12mins
- metabolized by plasma cholinesterase
- potassium issues
- serum K+ resise ~0.5mEq/L on average
- do not use in pts with pre-existing myopathy or myasthenic gravis or hyperkalemia
- hyperkalemia can occur in pts: burns >5d, denervation >5d, crush injury >5d old
- other complications:
- masseter spasm
- incrased GI, IOP, ICP
- malignant hyperthermia (treat with dantrolene)
- bradycardia
- prolonged apne with pseudocholinesterase deficiency or myasthenia gravis
- fasciculations
-non-depolarizing agents:
- rocuronium 1mg/kg
- onset as fast as succ in higher doses
- duration 30-45mins
- vecuronium 0.08-0.15mg/kg
- Atracurium 0.5mg/kg
- duration 25-40mins
- good for pts tih hepatic or renal failure
- SE: hypotension, histamine release, bronchospasm
8
Q
RSI: paralytic agent reversal
A
- give atropine 0.01mg/kg to prevent muscarinic SE
- then edrophonium 0.5-1mg/kg (acetylcholinesterase inhibitor)
- neostigmine
9
Q
Indications for nasotracheal intubation
A
- arthritis
- masseter spasm
- TMJ dislocation
- recent oral surgery
- procedure:
- spray nares with vasoconstrictor to minimize bleeding
- ETT 0.5-1mm smaller than oral ETT
- advance it straight back towards occiput, advance while rotating medially 15 deg, then advance tube with the initiation of insipration, swiftly
- any vocal sounds means the attempt failed
- distance from nares to carina is ~32cm in men and 28cm in women therefore advance tube to 28cm and 26cm repectively
10
Q
Video Laryngoscopy
A
- Glidescope: insert in the midline, look for uvula, then for epiglottis and then place in the valecula
- other video laryngoscopes: mcgrath, pentax
11
Q
Difficult Airways
A
- difficult mask ventilation defined by inability to maintain sats >90% despite optimal bagging
- failed airway: 3 unsuccesful attempts at intubation by and experienced operator or failure to maintain oxygenation
- presence of 2 out of the following is a predictor for difficult BVM:
- facial hair
- obesity
- edentulous pt
- advanced age
- snoring
- can apply lubrication to facial hair, use oral/nasal airways for difficult BVM
- features that make intubation difficult:
- facial hair
- obesity
- short neck
- small/large chin
- buckteeth
- high arched palate
- airway deformity (trauma, tumor, inflm)
-assessment:
- mandibular opening shoudl be 4cm (2-3 fingerbreadths)
- mentum to hyoid should be 3-4 fingers
- mallampati
- III - 5% failure rate
- IV - 20% failure rate
- neck mobility
12
Q
Increased ICP
A
- use etomidate or ketamine as induction agent (prevent hypotension)
- CPP = MAP-ICP
- TBI- goal to maintain MAP >90mmHg, avoid hyperventilation, keep PaO2 at 100mmHg
13
Q
Trauma and Airways
A
- >20% of c-spine injuries are not seen on lateral xr
- ~5% of blunt trauma requiring intubation are associated with unstable c-spine injuries
14
Q
Ventilators
A
-3 methods/setting:
- continuous mechanical ventilation
- mostly used in OR
- assist-control (A/C)
- pts with resp distress
- recommended for ER pts
- inspiration triggered by pts effort or elapsed time interval
- synchronized intermittent mandatory ventilation (SIMV)
- similar to a/c however if the pts breathing is above a set resp rate then the breaths are not assisted thereby increasing the WOB
15
Q
Extubation
A
- 1-2ml of 4% lido via ETT decreases bucking
- inspiratory capacity should be >15cc/kg before extubating
- there should be no intercostal/suprasternal retractions
- grips should be firm
- remove tube at end of deep inspiration, give oxygen by mask to prevent secretory reaccumulation
- if laryngospasm occurs treat with oxygen by positive pressure, if necessary use racemic epi
