(Obesity) Emergency Airway management Article (josh) Flashcards
Lets do some Fatties
Calculation for BMI
BMI= weight (KG) / Height (meters squared)
BMI classification
Overweight
Class I Obesity
Cass II obesity (formerly Morbid obesity)
Class III obesity (formerly Severe obesity)
Overweight- 25.0-29.9
Class I Obesity- 30.0- 34.9
Cass II obesity- 35.0-39.9
Class III obesity- > or= to 40
Physiologic and Anatomic Changes:
Both __1___ consumption and __2____ production are increased
1-Oxygen consumption
2-CO2 production
Physiologic and Anatomic Changes:
both the increased O2 consumption and CO2 production are a result of what?
metabolic activity in excess adipose tissue and from increased work required of supportive tissue
Physiologic and Anatomic Changes:
do to the increased O2 consumption and CO@ production, what occurs to the “safe apnea period” in obese pts
decreases
Physiologic and Anatomic Changes:
what happens to Airway resistance?
increases
Physiologic and Anatomic Changes:
what is different about the diaphragm?
abnormally elevated
Physiologic and Anatomic Changes:
what happens to “work of breathing”?
Increases
Physiologic and Anatomic Changes:
Why do obese pt’s have an increased work of breathing?
secondary to abnormal chest wall elasticity and resistance to caudad excursion of diaphragm.
Physiologic and Anatomic Changes:
Due to the increased airway resistance, abnormally elevated diaphragm, and increased work of breathing in obese pt’s, what is the affect on there respiratory pattern? (AKA what do their respiration’s look like)
Shallow and rapid
with limited ventilatory capacity
Physiologic and Anatomic Changes:
what is a common upper airway anatomical problem with obese pts?
pharyngeal wall collapse
Physiologic and Anatomic Changes:
what causes Pharyngeal wall collapse?
increased fat deposition in pharyngeal tissues
Physiologic and Anatomic Changes:
Obesity puts pt’s at an increased risk for other health related complication. give ex of these health care issues
atherosclerosis HTN DM Cardiomyopathy Arrhythmias
Physiologic and Anatomic Changes:
Obese pt’s have an increased risk for aspiration pneumonitis due to what?
Excess volume of gastric acid
increased intraabdominal pressures
Metabolism & Pharmacokinetics:
What type of drugs have a larger Vd
Lipophilic drugs (since Vd is dependent upon the amount of adipose tissue)
Metabolism & Pharmacokinetics:
what happens to GFR?
increases
Metabolism & Pharmacokinetics:
What happens to renaly excreted drugs in obese pt’s?
shorter 1/2 lives ( since their elimination is directly proportional to creatinine clearance)
Metabolism & Pharmacokinetics:
What effect does obesity have on Heapaticly eliminated drugs?
none
Airway Assessment:
the goal of airway assessment is to identify clinical features that predict difficulty in 3 main areas of emergency airway management. What are those 3 main areas?
1) Ventilation (w/bag mask pr extraglottic device)
2) Laryngoscopy & ETT intubation
3) Surgical Airway performance
Airway Assessment:
Obesity my complicate all 3 areas/task, thus airway management in the obese pt’s should always be considered what?
Potentially difficult
Airway Assessment: Bag Mask Ventilation
why is bag mask more difficult? (3 reasons)
Increased Airway resistance
Difficulty maintaining seal
Target O2 saturation difficult to obtain
Airway Assessment: Bag Mask Ventilation
What causes the increased Airway resistance?
redundant airway soft tissue
Increased body mass
Airway Assessment: Bag Mask Ventilation
what causes Difficulty in maintaining a seal?
requirement for higher pressures
Airway Assessment: Bag Mask Ventilation
what causes the Target O2 saturation to become difficult to obtain?
O2 consumption is increased
Airway Assessment: Tracheal intubation
what makes ETT placement difficult?
altered upper airway anatomy- resulting in poor view of glottis
Airway Assessment: Surgical airway
What makes surgical airways difficult in the obese?
excessive soft tissue in the anterior neck
- limits access to cricothyroid membrane
- Difficult to identify anatomic landmarks
Airway Management: Bag-Mask Ventilation
what is the best method for bag-mask ventilation w/ the obese pt?
two-person tech w/ oropharyngeal AND nasapharyngeal airways in place (yes it says AND nor or)
Airway Management: Bag-Mask Ventilation
what position of bed is best for bag-mask ventilation?
angled w/ head uo and feet down (AKA reverse trendelenburg)
Airway Management: Bag-Mask Ventilation
Why is reverse trendelenburg position good?
- Reduces pressure from abdominal contents on diaphragm
- Shifts weight of chest wall INFERIORLY (thus improving chest wall diaphragm excursion)
Airway Management: Tracheal Intubation
what position is best for ETT placement?
- Reverse trendelenburg (upright position)
- Ramped or head elevated position (extrenal auditory meatus and sternal notch horizontally aligned)
* traditionally sniffing position has been recommended to optimize glottic view during DL, but the ramped position appears to be more effective in obese pt’s*
Airway Management: PreOxygenation
this is the essential aspect of _____ intubation
RSI
Airway Management: PreOxygenation
what are some techniques to optimize preOxygenation?
1) Administer highest possible concentration of O2, via the best available means
2) remember NRB-mask gives 70% O2, a properly placed Bag-Mask unit gives 90-100% w/o assistance
3) Place in upright Position
4) use lubricated, BILATERAL nasal trumpets when needed
Airway Management: PreOxygenation
how long should you pre-Oxygenate
3-5 min
Airway Management: PreOxygenation
what is a way to aide in keeping O2 saturation up during the Apneic Phase of RSI
Nasal cannula in 5 LPM
thought this was cool
Medication Dosing:
How should induction drugs be dosed?
LBW
Medication Dosing:
how should rocuronium and Vecuronium be dosed?
IBW
Medication Dosing:
How should SCh be dosed
TBW
Medication Dosing:
What happens to Thiopental and Benzodiazepines effects?
prolonged (due to their lipophilicity and large Vd)
Medication Dosing:
what happens to Propofol and Opiods effects?
no real changes very similar to non-obese
Specific Equipment:
what type of equipment can make intubation easier
Short Laryngoscope handle
Larger Laryngoscope blades
ETT introducer (AKA bougie)
Specific Equipment:
What are some devices for airway management?
Optical or video Laryngoscope (glide scope) LMA and Laryngeal tubes Intubating LMAs Combitube (i always think of dwayne w/this) ETTI (bougie) Lighted stylet Fiberoptic stylet Flexible Fiberoptic
Thats it for fatties and airways article next slide is summary
FAT PEOPLE = Difficult airway
could have done this all in one slide
