AIRWAYS IN SPECIAL CONDITIONS

Question 1

what is the prevalence of obesity in the US?

Answer 1

36% of adults

Question 2

what is the best method for bringing an obese pt into the correct sniff position?

Answer 2

elevate trunk and head with sheets or ramp

Question 3

what is the primary concern of airway management when attempting to intubate an obese patient?

Answer 3

obese patients desaturate quickly due to decreased FRC (oxygen reserve)

Question 4

what is the component of the obese airway that presents the biggest problem in visualization of the vocal cords?

Answer 4

paraglottic soft tissue

Question 5

what is the overall obstetric mortality rate?

Answer 5

1:20,000

Question 6

what is the anesthesia-related obstetric mortality rate?

Answer 6

1:500,000

Question 7

what is the leading cause of anesthetic mortality?

Answer 7

airway management

Question 8

what are the risk factors of pregnancy and airway management?

Answer 8

failure to intubate

aspiration

hypoxemia

urgency for two patients

failure to prepare completely

Question 9

what are the aspiration risks for pregnant women?

Answer 9

solid and or liquid ingestion soon before delivery

decreased gastric emptying

increased gastric acidity

Question 10

what factors decrease gastric emptying in gravid women?

Answer 10

progesterone

stress of labor

narcotics

Question 11

what factors predispose gravid women to decreased gastro-esophageal sphincter tone and aspiration?

Answer 11

reflux

anticholinergics

narcotics

insertion/removal of NG tube

Question 12

what percent of obstetric anesthia-related aspiration is due to hiatial hernia?

Answer 12

27%

Question 13

how much is gastric pressure increased in mothers pregnant with a single child?

Answer 13

7 → 17cmH2O

Question 14

how much is gastric pressure increased in mothers pregnant with twins?

Answer 14

7 → 40cmH2O

Question 15

how much does lithotomy postioning increase gastric pressure increased in gravid mothers?

Answer 15

17 → 40cmH2O

Question 16

what are the contributing factors that increase the likelihood of a failed intubation in gravid pts?

Answer 16

upper airway edema

adiposity of head, neck, trunk

breast enlargement

Question 17

by what margin does pregnancy increase the incidence of failed intubations?

Answer 17

increased 10 fold

nongravid – 1:2500

gravid – 1:250

Question 18

what are the contributing factors that increases the risk of hypoxemia in gravid pts?

Answer 18

20% decrease in FRC

V_O2 increase

Question 19

how does V_O2 vary in gravid term vs. active labor pts?

Answer 19

20% increase V_O2 – term

60% increase V_O2 – active labor

Question 20

what four steps must you take to manage increased airway risks of gravid pts?

Answer 20

identify risks

prevent acid reflux

identify number of fetuses

vigilance during active labor

Question 21

what position should the gravid pt be in while evaluating the airway?

Answer 21

supine

Question 22

what physical characteristics of the gravid pt should be assessed during evaluation of the potentially difficult airway?

Answer 22

head, neck, trunk, breasts

Question 23

what is the established patient preparation protocol for labor?

Answer 23

1. NPO – provide good hydration
2. cimetidine (tagamet) 300mg IV – 60min prior (histamine receptor antagonist; inhibits stomach acid production)
3. metoclopramide (reglan) 10mg IV – 30min prior (anti-nauseau and gut-motility inhibitor)
4. sodium citrate 30ml PO – immediately prior (used as an antacid)

Question 24

outline plan A for orotracheal intubation of the gravid pt

Answer 24

goal: prepare for 1st attempt success

optimize pt position

provide complete preoxygenation

down size ETT

utilize sellick maneuver throughout

use ETT introducer if needed

Question 25

what is the goal of Plan B when attempting to intubate the gravid pt?

Answer 25

oxygenate/support both pts

Question 26

what should be applied continuously from Plan A to Plan B airway management of the gravid pt?

Answer 26

sellick maneuver

Question 27

what is the goal of Plan C airway management of the gravid pt?

Answer 27

establish viable airway with oxygenation

Question 28

what two methods of airway management are viable for Plan C airway management of the gravid pt?

Answer 28

HPOV or RGW

Question 29

what three structures should be evaluated for arthritis in the geriatic airway?

Answer 29

the cervical spine, the cricoarytenoid joint, and the temporomandibular joint

Question 30

what changes in the chest wall and lungs of the geriatric pt may present difficulty for airway management?

Answer 30

muscle loss, stiffer chest wall

decreased lung elastic recoil

decreased vital capacity

Question 31

despite the comorbidities of the geriatric chest wall and lungs, what component of total lung capacity remains unaffected?

Answer 31

FRC

Question 32

how might arthritis in the cervical spine impact DL/intubation?

Answer 32

limited ROM – little to no atlanto-occipital extension

Question 33

how might arthritis of the TMJ impact DL/intubation?

Answer 33

limited mouth opening – have alternate plan for intubation

Question 34

how might arthritis of the cricoarytenoid joint impact the geriatric airway?

Answer 34

hoarseness (needs to be documented) – may limit the ability of the vocal cords to relax

Question 35

how might changes in the chest wall and lungs impact airway management of the geriatric pt?

Answer 35

decreased ability to cough and protect airway – be cautious during emergence; pt must be able to cough and protect airway

Question 36

how might dentition of the geriatric pt (endentulous, facial skin looseness) affect airway management?

Answer 36

increased difficulty in mask fit/ PPV – use adjuncts (OAW, face mask strap)

Question 37

what risk does the pt with osteoporosis present?

Answer 37

increased fracture risk

Question 38

how might the reliability and cooperation of a senile pt affect airway evaluation and management?

Answer 38

poor historian – use alternate source for history

increased safety risk – minimum to no sedation

Question 39

when drainage in the neck is compromised, how is airway patency affected?

Answer 39

edema in the glottic tissues decrease vocal cord visualization leading to increased risk of intubation failure

Question 40

definition: supine, head lower than heart, legs and pelvis elevated

Answer 40

trendelenburg position

Question 41

the trendelenburg postition was first described by whom?

Answer 41

Dr. Willy Meyer (1885)

credited to his teacher, Friedrich Trendelenburg, used for urologic surgery in 1870

Question 42

when was the trendelenburg position first used in the US?

Answer 42

1890

Question 43

what advantages does tburg give for surgical procedures?

Answer 43

physical access to specific regions

moves abdominal contents cephalad

alters regional circulation

Question 44

how does tburg negatively affect anesthetic procedures?

Answer 44

increases diameter of jugular veins (increases cephalad edema)

moves regurgitated material into pharynx

Question 45

what parts of the patients anatomy should remain in neutral longitudinal alignment during lithotomy positioning?

Answer 45

head, neck, thorax should remain in neutral longitudinal alignment

Question 46

what should be avoided when using the kidney rest for lateral decubitus positioning?

Answer 46

do not compress abdominal contents with the kidney rest