Module 4

Question 1

how is pH measured

Answer 1

increased H+ = decreased pH (acidic)
decreased H+ = increased pH (alkalotic)

Question 2

what are the aspects measured in an ABG

Answer 2

• pH
• PCO2
• PO2
• HCO3

Question 3

what is buffering pairs

Answer 3

1. bicarbonate/ carbonic acid system
2. disodium/ monosodium phosphate buffer system
3. haemoglobin/ oxyhaemoglobin system
4. protein buffer system

Question 4

what is bicarbonate/ carbonic acid buffer

Answer 4

• disease process results in less bicarb = more H+ = pH decreases
• to overcome this and maintain normal pH there will be less carbonic acid produced = less H+ = pH returns to normal

Question 5

what is respiratory system in acid base balance

Answer 5

• the lungs are important
• it will compensate for disturbance of metabolic origin
• works within minutes to hours

Question 6

what is renal system in acid base balance

Answer 6

• kidneys are the long term regulators of blood pH
• it will compensate for disturbance of respiratory origin
• works from hours to days
• the kidneys will retain or eliminate both HCO3 and H+ ions as needed

Question 7

what are the lungs and kidneys roles?

Answer 7

• attempt to balance each other to maintain acid base balance in blood
• if pH changes because of a repsiratory disorder the renal system will be responsible for making corrections to balance blood

Question 8

what is acidosis

Answer 8

• too much H+
• pH <7.35

Question 9

what is alkalosis

Answer 9

• not enough H+
• pH >7.45

Question 10

what is being measured in ABG

Answer 10

• pH - measures of H+ in blood
• PCO2 - amount of dissolved CO2 in blood
• HCO3 - amount of HCO3 in blood
• PO2- amount of dissolved O2 in blood
• BE - amount of excess or insufficient HCO3 in the system, negative BE = deficit of HCO3 in blood = excess acid
• SaO2 - % of hB saturated with oxygen

Question 11

normal values of ABG

Answer 11

pH
* range 7.35-7.45
* acidosis - <7.35
* alkalosis - >7.45

PaCO2
* range - 35-45mmHg
* acidosis - >45
* alkalosis - <35

HCO3
* range - 22-28 mEq/L
* acidosis - <22
* alkalosis - >26

PaO2
* range - 80-100 mmHg
* hypoxaemia - <80

SpO2
* range - 95 - 100%
* hypoxaemia - <95

Question 12

causes and risk factors of pneumonia

Answer 12

causes
* aspiration of orophaeyngeal secretions composed of bacterial flora or gastric content
* inhalation of contaminants
* contamination from systemic circulation

risk factors
* advanced age
* compromised immunity
* underlying lung disease particularly COPD
* alcoholism
* smoking
* malnutrition
* chest trauma
* impaired swallowing

Question 13

what is the most common cause of chronic obstructive pulmonary disease

Answer 13

tabacco smoking

Question 14

respiratory rate and depth are controlled by what?

Answer 14

apneustic and pneumotaxic centres in the pons

Question 15

why is monitoring respiratory status a nursing priority when a client with COPD is recieving oxygen

Answer 15

decreased arterial oxygen is the stimulus for breathing in a client with COPD