Mechanical Ventilation

Question 1

ventilation

Answer 1

movement of gas in and out of the alveoli

Question 2

ventilate is defined by

Answer 2

PaCO2

normal 35-45 mmHg

Question 3

oxygenation is defined by

Answer 3

PaO2 or SpO2

Question 4

T/F whe breathing 100% O2 oxygenation cannot be improved by more ventilation

Answer 4

True

apneic oxygenation is possible - ventilation may not be needed for oxygenation

Question 5

T/F using 100% oxygen can insure good oxygenation in most circumstances

Question 6

resistance limits

Answer 6

flow

resistance = pressure difference / flow

Question 7

compliance limits

Answer 7

Volume

complience = volume / flow

Question 8

what is mechanical ventilation

Answer 8

method of artificial ventilation where mechanical means is used to assust or replace spontaneous breathing

provided by ventilator or person

Question 9

types of ventilation

Answer 9

spontaneous

assisted

mandatory (or controlled)

Question 10

IPPV

Answer 10

intermittent positive pressure ventilation

positive pressure is maintained only during inspiration

Question 11

IMV

Answer 11

intermittent mandatory ventilation

operator sets a predetermined number of positive breaths but patient can also breathe freely inbetween

Question 12

CPAP

Answer 12

continuous positive airway pressure

spontaneous breathing with positive pressure durinng inspiration and expiration

Question 13

PIP

Answer 13

peak inspiratory pressure

inflates the alveoli, opens atelectasis or causes barotrauma

Question 14

PEEP

Answer 14

positive end expiratory pressure

keeps alveoli open (prevents re-collapse)

Question 15

T/F the benefit of PEEP is questionable durinf routine anesthesia

Answer 15

True

Question 16

indications for PEEP

Answer 16

open thorax

lung parenchymal disease

following alveolar recruitment maneuver

Question 17

indications for mechanical ventilation under anesthesia

Answer 17

want to decrease PaCO2 (intubated patients on 100% O2)

breathing air: hypoemia

Question 18

specific indications for MV under anesthesia

Answer 18

neuromuscular blockade

thoracic surgery

control of intracranial pressure

chest wall or diaphragmatic trauma

Question 19

side effects of MV

Answer 19

impairs venous return and cardiac output

may cause hypotension

Question 20

direct effects of hypercapnia

Answer 20

peripheral vasodilation

decreased myocardial contractility

increased intracranial pressure

Question 21

indirect effects of hypercapnia

Answer 21

via catecholamine release

tachycardia

increased myocardial contractility

Question 23

T/F ventilating during anesthesia is a debated issue (esp. in horses)

Answer 23

True

Question 24

permissive hypercapnia may be acceptable up to

Answer 24

60-70 mmHg for the purpose to improve circulation

Question 25

tidal volume in healthy lungs

Answer 25

10-15 ml/kg

Question 26

respiratory rate for ventilating healthy lungs

Answer 26

10-15 breaths/min

Question 27

inspiratory time (healthy lungs)

Answer 27

1-2 sec

Question 28

tidal volume in sick lungs is bigger/smaller

Answer 28

smaller

Question 29

2 respiratory assist devices

Answer 29

ambu bag

demand valve

Question 30

modes of MV

Answer 30

volume controlled ventillation mode

pressure controlled ventilation mode

Question 31

common source of driving power

Answer 31

pneumatically driven

uses pressurized gas source

Question 32

control variables

Answer 32

flow controlled

pressure controlled

ventilator controls these variables

Answer 33

u

Question 34

cycle variables

Answer 34

defines the start of expiration

volume, pressure, and time cycled

Question 35

trigger variable

Answer 35

defines start of inspriation - inspiration starts when a set value is reached

pressure and flow trigger

Question 36

limit variable

Answer 36

stops inspiration

volume and pressure limit

Question 37

T/F in an atelectic lung, increasing alveolar minute ventilation can remove more CO2 but without opening the atelectasis you will not be able to improve oxygenation

Answer 37

True