General Anesthesia Induction/Intubation Equipment Flashcards Preview

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Flashcards in General Anesthesia Induction/Intubation Equipment Deck (36)
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1

Anesthesia, or anesthesia means

-greek meaning an= without and asthesia: sensation
-condition of having sensation (including feeling of pain) blocked or temporarily taken away
-"reversible lack of awareness"
-total lack of awareness of lack of awareness of a part of the body such as a spinal anesthetic (regional anesthetic)

2

GA Induction

-pharmacological induction of a sate of loss of consciousness
-loss or alteration of reflexive responses which effects the respiratory, CV, and NM systems
-types: inhalation induction (mask), IV (RSI or modified RSI) combination

3

Main sequences of most GA inductions typically includes

1. Monitor application
2. Pre-oxygenation
3. Induction agents given
4. Airway support through masking, LMA (supraglottic) or ETT placement

4

Pre-oxygenation

1. FRC: lung volume at the end of normal exhalation (gas patient will drawn upon when we induce apnea)
2. At FRC, elastic recoil forces of the lungs and chest wall are equal but opposite and there is no exertion by the diaphragm or other respiratory muscles
3. ERV: lung volume after normal tidal breathing + RV: lung volume remaining after exhalation
4. Pre-oxygenation increased apnea threshold by filling the FRC with oxygen

5

Mask Induction Indications

1. Pediatric patient that are NPO where IV placement may be distressing
2. Adult patients that are NPO that are difficult IV placement or unable to cooperate with IV placement

6

Typical Mask Induction Sequence

1. Monitors, sometimes just pulse ox
2. Nitrous/Oxygen mixture then add servo
3. Gentle mask ventilation until IV placed
-patient can be susceptible to obstruction, laryngospasm and bradycardia in this time period. Delicate balance of anesthetic depth, too light can lead to laryngospasm and too deep can lead to bradycardia
4. Intubation or airway placement after IV placed
5. Some GAs may be able to just mask without IV- must have back up plan (IM or sublingual drugs)

7

Laryngospasm

-mediated by the superior laryngeal nerve in response to irritating glottic or supraglottic stimulation such as presence of food, blood, vomit or airway secretions. Occurs most frequently with light anesthesia, upon induction or emergence*
-false cords and epiglottic body come together firmly and allow no air flow and no vocal sound

8

Treatment of Laryngospasm

-forward displacement of jaw and apply positive pressure with 100% oxygen
-severe spasm may require small doses of such (0.1 to 1 mg/kg) and re-intubation. May be given IM or SL
-laryngospasm will eventually cease as hypercapnia and hypoxia develop

9

Intravenous Induction

-General Sequence of patient that has been NPO
-Pre-oxygenation (filling FRC with O2)
-IV induction agent
-Mask airway
-IV paralytic if ETT used
-no paralytic if LMA placed
-placement of airway device and confirmation of placement (bilateral breath sounds and ETCO2)

10

RSI

-Anesthesia induction sequence that aids in securing airway with an ETT as quickly as possible. There is no masking after induction agent is given
-Reduces the time at risk for pulmonary aspiration and hypoxemia
-Indications: full stomach, severe GERD

11

RSI Sequence

1. Pre-oxygenate up to 5 minuets
2. IV anesthetic agent
3. Rapid-onset NMB (sux)
4. Use of cricoid pressure
5. Intubation with ETT
6. Release of cricoid pressure after confirmation of ETT placement

12

Modified RSI

-Patient is masked with gentle pressure while cricoid pressure is maintained
-may be done if you need extra oxygenation or feel the need to see if the patient has a good mask airway

13

Cricoid Pressure

-aka Sellick Maneuver
-Used to prevent pulmonary aspiration since its description by Sellick
-hypothetical basis is that pressure on the front of the cricoid cartilage is transmitter to its posterior lamina, which occludes the esophagus by compression against vertebral bodies
technique: find thyroid prominence, go slightly below to cricoid cartilage. Pressure is placed with thumb and index finger on lateral edges of cricoid cartilage (3N posterior)

14

Cricoid pressure during laryngoscopy

-maintain cricoid pressure during laryngoscopy
-do NOT release cricoid pressure until after confirmation of successful intubation: visualization of ETT through vocal cords, fogging of OET, ETCO2, bilateral breath sounds

15

Cricoid disadvantages

-reduces tone of lower esophageal sphincter so the risk of regurgitation from stomach to esophagus is increased
-impairs insertion of the laryngoscope
-degrade view of larynx
-impede passage of an introducer or ET
-causes airway obstruction
-application of CP by an assistant impedes external laryngeal manipulation by anesthesiologist
-fracture of cricoid cartilage has be reported
- rupture of esophagus from vomiting in the presence of cricoid pressure
-low levels of cricoid pressure might be safe in the presence of vomiting

16

Induction complications

-induction involves rendering a patient breathless and unconscious
-in any typical induction involves anticipating difficulties and having a back up plan
-laryngospasm
-bronchospasm

17

Difficult airway in summary

1. assess airway and try to anticipate difficult intubation
2. if so, then consider doing awake fiberoptic or keep the patient breathing
3. if at any time you are unable to intubate a patient and unable to mask a patient, the LMA is next line
4. surgical airway is the end option if can't intubate, cannot ventilate

18

Miller vs. Mac Blade

1. Miller is a straight blade. Lifts epiglottis.
2. Mac is a curved blade. Curves into vaceula.

19

Airway assessment

1. Grade 1 View= Class I Mallampati score. Can visualize uvula, hard palate and soft palate. Can visualize vocal cords
2. Grade 2 View= Class II Mallampati score. Can somewhat see vocal cords
3. Grade 3 View= Class III Mallampati score. Can only see epiglottis
4. Grave 4 View= Class IV Mallampati score. All you can see is palate.

20

Intubation Equipment: Direct Visualization

Direct Visualization or Direct Laryngoscopy (DL)
-Laryngoscope with light source and blade
-NO CAMERA

21

Intubation Equipment: Fiberoptic Camera Assisted

-video assisted
-rigid fiberoptic
-a version of DL blade with a camera
-Flexible fiberoptics

22

For optimal visualization what position should your patient be in?

-sniffing position

23

List a few types of laryngoscope handles and blades

1. Large, medium, penlite, stubby, mini and mico mini handles
-Prior to induction, light source must be checked
2. Straight Miller blade or Curved MAC blade

24

Sizes of Macintosh and Miller blades?

1. Infant size O neonate
2. Child size 2
3. Most adults size 3
4. Large adult size 4

25

DL Technique with a MAC Blade

1. Hold laryngoscope blade in left hand and scissor mouth open with right thumb and 3rd finger
2. Insert blade at the right side of the mouth, sweep tongue out of the way as you insert tip of blade into vallecular space
3. Make sure lip is not caught under blade on top or bottom
4. Remove fingers once blade is inserted and epiglottis is visualized

26

MAC DL technique angle of blade

1. Initial angle should be downward as you insert blade
2. Once epiglottis is visualized upward force brings posterior pharynx and vocal cords into view
3. Teeth are NOT used as fulcrum*

27

Tips with Mac Blade

1. If you do not initially see epiglottis pull your blade back a little, sometimes you are in too deep and the blade is actually under the epiglottis and in the esophagus. Epiglottis will fall into view as you pull back (happens with Mac 4)
2. If the patient has large epiglottis, the ETT can be used to gently lift the epilogs and you may get a better view

28

DL Technique with Miller Blade

1. Control of the tongue is critical with straight blade
2. Small flange height prevents any ability to sweep the tongue. Proper position is achieved with straight blades by deliberately directing the bade to the right paraglossal space
3. No tongue should be present to the right of the blade
4. Full insertion of blade should occur through the right lateral mouth over the molar dentition, while the distal blade may then be directed medially, the proximal blade should never be brought back towards midline. (It can hit central incisors)
5. After the epilogs edge is identified, the handle must be titled forward
6. The blade is then inserted slightly farther (1-2 cm) and the tip passed under the epiglottis. Once the epiglottis is trapped under the blade, the blade is rocked slightly backward and upright and then the lifting force increased

29

Direct Visualization or Direct Laryngoscopy

-fast and simple
-requires some movement of the head and neck and takes some training to become sufficient

30

What if we can't or shouldn't move the patients neck?

-Rigid fiberoptic laryngoscopes use fiberoptic to transmit image from tip of device to eye piece
-elevates the jaw without the need for neck extension and useful with small mouth opening
-ETT slides along device or through device