Capnography

Question 1

what is the definition of capnography

Answer 1

measurement of exaled carbon dioxide

waveform represents stages of inhalation and exhaustion

4 stages

Question 2

what is phase A -B of capnography?

Answer 2

between A and B, represents late phase of inspiration, and beginning of exhalation

Question 3

what is phase B-C of capnography

Answer 3

between B and C, represents continued exhalation of air from remaining dead space and proximal alveoli
- thus phase should rise sharply as CO2 content increases

Question 4

what is phase C of capnography?

Answer 4

-plateau phase
- reflects airflow from alveoli during ventilation
- nearly constant CO2 level
- considered end- tidal point(highest point of CO2 )

Question 5

what is phase D of capnography?

Answer 5

• between D and A
• Last phase that identifies inspiration
• rapid download as patient inhales and should terminate at zero

Question 6

causes of sudden LOSS of etco2 and drop to ZERO

Answer 6

airway disconnected
ET tube dislodged or kinked, obstructed
malfunction of ventilator
esophageal intubation

Question 7

causes of sudden DECREASING etco2 with LOSS of plateau

Answer 7

ET tube leaking or deflated
partial airway obstruction

Question 8

causes of LOSS of etco2 plateau

Answer 8

bronchospasm
muscles plugging
incomplete or obstructed exhalation
ET tube partially kinked

Question 9

causes of SUDDEN DECREASE in etco2 levels

Answer 9

pulmonary embolism
drop or loss of circulation
hypothermia
decreased metabolism
hypovolemia

Question 10

causes of LOW SUSTAINED normal waveform

Answer 10

hyperventilation
decreased metabolism
hypothermia

Question 11

causes of rising baseline in capnography?

Answer 11

air trapping
auto peeping
rebreathing of Co2