Mech ventilation Dr Ambrisko Flashcards Preview

My 2016 RUSVM Anesthesia > Mech ventilation Dr Ambrisko > Flashcards

Flashcards in Mech ventilation Dr Ambrisko Deck (23):
1

What defines ventilation

PaCO2

2

What defines oxygenation

How is it monitored

PaO2 or SpO2

arterial blood gas or pulse oximetry

3

What is considered hypoxemia

PaO2 <60 mmHg ⇔ SaO2 < 90%

4

How can oxygenation be improved?

How can good oxygenation be insured in most circumstances?

When breathing 100% O2 it CANNOT be improved by MORE ventilation

Could be improved by special respiratory manoeuvers

Use 100% oxygen

5

What does resistance & compliance limit?

flow & volume respectively!

6

what is the respiratory cycle

Inspiration

inspiratory flow time

inspiratory pause

Expiration

expiratory flow time

expiratory pause

7

what is mechnical ventilation (MV)

artificial ventilation where mechanical means is used to assist or replace spontaneous breathing

provided by a ventilator or a person

8

What are the types of ventilation

Spontaneous - pt determines when & how

Assisted - pt derermines when, ventilator determines how

Mandatory (or controlled) - ventilator determines when & how

9

What is IPPV

Intermittent Positive Pressure Ventilation

positive pressure only during inspiration (no PEEP)

10

what is IMV

Intermettent Mandatory Ventilation

predetermined # of positive breaths but pt can breath inbetween freely

11

what is CPAP

Continuous Positive Airway Pressure

spontaneous breath w/ positive pressure during both inspiratory & expiratory phases

can prevent lung collapse

12

what is PIP

Peak Inspiratory Pressure

highest pressure during inspiration

inflates alveoli, opens atelectasis, causes barotrauma

13

what is PEEP

Positive End Expiratory Pressure

positive pressure maintained during expiration

pressure keeps alveoli open (prevents re-collapse of alveoli)

14

Indications for PEEP

open thorax

lung parenchymal dz

following alveolar recruitment maneuver

15

indications for MV under anesthesia

in intubated pt that breathe 100% O2 used to DECREASE PaCO2

(to tx hypoventilation)

16

specific indications for MV under anesthesia

neuromuscular blockade

throacic sx

control of ICP

chest wall or diaphragmatic trauma

17

Side effect of MV

how to tx side effects

may cause hypotension in hypovolemic pt

Volume loading

change ventilator settings

turn off ventilator

Inotropic drugs (e.g. dobutamine)

pneumothorax & lung injury

18

Effects of hypercapnia

Direct effects of CO2:

peripheral vasodilation

decr myocardial contractility (inotropy)

incr ICP

bradycardia

Indirect effects of CO2 (via catecholamine release):

tachycardia

incr myocardial contractility

19

ventilating healthy lungs

TV: 10-15 ml/kg

for ruminants: 6-10 ml/kg

RR: 10-15(20) breath/min

Inspiratory time: 1-2 sec

PIP: 10 cmH2O if BW <10kg

20 cmH2O if BW >10kg

PEEP: 0-2 cmH2O

 

20

How is manual ventilation performed

  1. close pop-off
  2. squeeze reservoir bag until desired pressure reached
  3. release bag so pt passively expire
  4. open pop-off
  5. repeat cycle q 6 secs (10/min)

21

What are respiratory assist devices

ambu bag

demand valve

22

modes of MV

volume controlled

pressure controlled (preffered)

23