Respiratory Disorders and pH Imbalances Flashcards
(105 cards)
1
Q
What is the normal blood pH range?
A
7.35 – 7.45
2
Q
What happens to proteins when pH changes?
A
Proteins change their confirmation and structure (denature) and are unable to function normally
3
Q
Define acid in the context of body function.
A
Donates free H+ ions when dissolved in water
4
Q
Define base in the context of body function.
A
Accepts free H+ ions when dissolved in water
5
Q
Define pH.
A
Scale (0-14) that measures acids and bases; with 7 as neutral
6
Q
What pH level indicates acidosis?
A
pH falls below 7.35
7
Q
What pH level indicates alkalosis?
A
pH rises above 7.45
8
Q
What is the consequence of a 0.1 unit change in pH for enzymes?
A
It may reduce activity by 90%
9
Q
What is the role of chemical buffer systems?
A
React with a relatively strong acid (or base) to replace it with a relatively weak acid (or base)
10
Q
What are the three types of chemical buffer systems?
A
- Bicarbonate
- Phosphate
- Protein
11
Q
What is the bicarbonate-carbonic acid buffer system ratio required to maintain normal pH?
A
20 bicarbonate ions (HCO3-) to 1 carbonic acid (H2CO3)
12
Q
What is the response time of the respiratory system in pH regulation?
A
Minutes
13
Q
How do kidneys regulate H+?
A
Excrete or retain H+ (acid) and excrete or retain bicarbonate ions (base)
14
Q
What is the pH range for cell death?
A
Outside of pH 6.8 – 7.7
15
Q
What is respiratory acidosis associated with?
A
Hypoventilation leading to increased CO2 levels
16
Q
What are common causes of metabolic acidosis?
A
- Severe diarrhea
- Renal disease
- Untreated diabetes mellitus or starvation
17
Q
What can acidosis cause in relation to potassium levels?
A
Hyperkalaemia
18
Q
What is the result of hyperventilation?
A
Respiratory alkalosis
19
Q
What is the primary compensation mechanism for metabolic acidosis?
A
Increased rate and depth of breathing
20
Q
What does ABG stand for?
A
Arterial blood gas
21
Q
What can be measured in an ABG test?
A
- pH
- Carbon dioxide (PCO2)
- Bicarbonate (HCO3-)
- Oxygen (PO2)
- % saturation (O2)
22
Q
What indicates uncompensated respiratory alkalosis?
A
pH > 7.45 and CO2 levels < 35mmHg
23
Q
What indicates uncompensated metabolic alkalosis?
A
pH > 7.45 and HCO3- levels > 29 mmol/L
24
Q
What is the consequence of impaired respiratory regulation?
A
Acid-base imbalances
25
True or False: Acidosis is more common than alkalosis.
True
26
What happens during CO2 unloading at the lungs?
Reaction shifts to the left and H+ is incorporated into H2O
27
What is the role of the brain stem in respiratory regulation?
CO2 production must equal CO2 excretion to maintain constant pH
28
What is a characteristic of compensated respiratory acidosis?
Elevated PCO2 (>45mmHg) and elevated HCO3-
29
What can cause metabolic alkalosis?
* Vomiting or gastric suctioning
* Some diuretics
* Overdose of antacids
30
What is the expected HCO3- level in uncompensated metabolic acidosis?
Low (<22 mmol/L)
31
What is the relationship between H+ and potassium ions during acidosis?
Hydrogen ions enter cells in exchange for potassium ions leaving cells
32
What is the expected blood pH in uncompensated respiratory acidosis?
pH < 7.35
33
What is the expected blood pH in uncompensated metabolic alkalosis?
pH > 7.45
34
What happens to bicarbonate levels during respiratory acidosis compensation?
Kidneys retain HCO3-
35
What is the impact of low H+ levels on respiratory drive in metabolic alkalosis?
Decreases respiratory drive
36
What is the significance of the pH value in an ABG test?
Indicates acidosis (pH<7.35) or alkalosis (pH>7.45)
37
What is the expected normal range for HCO3-?
22-29 mmol/L
38
What indicates respiratory acidosis in terms of PCO2 and pH?
PCO2 >45mmHg and pH <7.35
39
What indicates respiratory alkalosis in terms of PCO2 and pH?
PCO2 <35mmHg and pH >7.45
40
What is the implication if PCO2 is in the normal range?
The respiratory system is not responsible for the imbalance; the cause is metabolic.
41
What bicarbonate (HCO3-) level indicates metabolic acidosis?
HCO3- values below 22mmol/L (and pH <7.35)
42
What bicarbonate (HCO3-) level indicates metabolic alkalosis?
HCO3- values above 29mmol/L (and pH >7.45)
43
What is the next step after checking bicarbonate levels in acid-base imbalance?
Determine if compensation is occurring.
44
What does it mean if an imbalance is fully compensated?
The pH may be normal, but bicarbonate or carbon dioxide levels will not be normal.
45
What is the normal range for pH in plasma?
7.35-7.45
46
What is the normal range for PCO2 in plasma?
35-45 mmHg
47
What is the normal range for bicarbonate (HCO3-) in plasma?
22-29 mmol/L
48
What does a pH of 7.6 indicate in terms of acid-base status?
Alkalosis
49
What PCO2 level suggests respiratory alkalosis?
24mmHg
50
In the first example, what suggests no compensation?
Normal HCO3- level of 23mmol/L
51
What does a pH of 7.48 indicate in terms of acid-base status?
Alkalosis
52
What does an elevated PCO2 of 46mmHg suggest in the second example?
Respiratory compensation
53
What does a pH of 7.28 indicate?
Acidosis
54
What does an elevated HCO3- level of 30mmol/L suggest in the third example?
Renal compensation
55
What is a treatment option for metabolic acidosis?
Bicarbonate may be given.
56
What is a treatment option for metabolic alkalosis?
Infusion of chloride-containing solution.
57
What is a treatment option for respiratory acidosis?
As per metabolic acidosis.
58
What is a treatment option for respiratory alkalosis?
As per metabolic alkalosis.
59
What is the primary source for understanding acid-base balance mechanisms?
Porth’s Essentials of Pathophysiology, 5th edition, Chapter 8.
60
Fill in the blank: Abnormalities of acid-base balance are classified as _______ or respiratory.
metabolic
61
What is the definition of asthma?
A chronic inflammatory disorder of the airways characterized by reversible airflow obstruction and resulting in cough, wheeze, chest tightness, and shortness of breath.
## Footnote
Asthma causes bronchial hyper-responsiveness, constriction of the airways, and variable airflow obstruction that is reversible.
62
What are common triggers for asthma?
* Outdoor allergens (e.g., pollens, moulds)
* Tobacco smoke
* Chemical irritants in the workplace
* Air pollution
* Cold air
* Extreme emotional arousal
* Physical exercise
* Certain medications (e.g., aspirin, beta-blockers)
* Respiratory infections (e.g., colds, flu)
## Footnote
The fundamental causes of asthma are not completely understood.
63
What are the strongest risk factors for developing asthma?
A combination of genetic predisposition with environmental exposure to inhaled substances and particles that may provoke allergic reactions or irritate the airways.
## Footnote
Examples include indoor allergens like house dust mites, pet dander, and cockroaches.
64
What are the symptoms during an asthma attack?
* Shortness of breath
* Chest tightness
* Dry irritating cough
* Wheeze
* Dyspnoea
## Footnote
During an attack, bronchial hyperactivity, inflammation, and increased mucus production occur.
65
What characterizes the early and late responses in asthma?
Early phase is bronchoconstriction; late phase (up to 6 hours after exposure) is inflammation and bronchoconstriction.
66
What are the components of asthma pathophysiology?
* Episodic attacks of bronchospasm
* Bronchial inflammation
* Mucosal oedema
* Increased mucous production
* Bronchial smooth muscle contraction
* Thickening of airway walls
## Footnote
Immunoglobulin E (IgE) is involved in the degranulation of mast cells, releasing inflammatory mediators.
67
What are some prevention strategies for asthma?
* Reduce exposure to allergens
* Clean and ventilate living spaces
* Eliminate dust-collecting furniture
* Use mite-impermeable covers
* Reduce air pollution
* Smoking cessation
* Immunisation against flu
* Reduce occupational exposure to irritants.
68
What is the initial management for an asthma attack?
* Immediate administration of oxygen
* Inhaled beta-agonist bronchodilators
* Oral corticosteroids
* Careful monitoring of gas exchange and airway obstruction.
## Footnote
Antibiotics are not indicated for acute asthma unless a bacterial infection is documented.
69
What characterizes obstructive lung diseases?
Airflow obstruction or limitation, causing difficulty with expiration.
## Footnote
Examples include COPD, asthma, cystic fibrosis, and bronchiectasis.
70
What defines restrictive lung diseases?
Decreased compliance of lung tissue leading to reduced lung compliance and decreased lung volumes.
## Footnote
RLD can be caused by pulmonary causes (e.g., inflammation) or other causes (e.g., chest wall injury, obesity).
71
What does spirometry measure?
* Airflow to determine how much air is inhaled/exhaled
* Forced Vital Capacity (FVC)
* Forced Expiratory Volume in 1 second (FEV1)
* FEV1/FVC ratio
* Diffusing capacity (DLco)
## Footnote
Conditions decreasing surface area of alveolar-capillary membrane or altering/thickening alveolar membranes can be assessed.
72
What is the significance of the FEV1/FVC ratio?
Diagnosis of COPD is made when the FEV1/FVC ratio is less than 70%.
73
What are the spirometry test results for obstructive lung disease?
* FVC: Decreased or Normal
* FEV1: Decreased
* FEV1/FVC ratio: Decreased
* TLC: Normal or increased
## Footnote
TLC is the gold standard for the diagnosis of a restrictive defect.
74
What are the spirometry test results for restrictive lung disease?
* FVC: Decreased
* FEV1: Decreased or normal
* FEV1/FVC ratio: Increased or normal
* TLC: Decreased.
75
What does DLCO measure?
The ability of lungs to diffuse gas across alveoli; decreased in emphysema and interstitial lung diseases.
76
What is Chronic Obstructive Pulmonary Disease (COPD)?
A disease characterised by progressive development of airflow limitation that is not fully reversible and destruction of lung parenchyma.
77
What are the two major conditions included in COPD?
Emphysema and Chronic Bronchitis.
78
How many cases of COPD were reported globally in 2010?
384 million cases.
79
What was COPD's rank as a cause of death in 2012?
Fourth leading cause of death.
80
What is the projected rank of COPD as a cause of death in 2020?
Third leading cause of death.
81
What is the prevalence of COPD in adults over 45 years of age?
Affects about 1 in 7 adults.
82
What is the primary cause of COPD?
Tobacco Smoke.
83
List some risk factors for COPD.
* Indoor air pollution
* Occupational dusts and chemicals
* Frequent lower respiratory infections
* Genetic conditions (e.g. alpha 1 anti-trypsin deficiency)
* Poorly controlled Asthma.
84
What common diseases often coexist with COPD?
* Cardiovascular disease
* Skeletal muscle dysfunction
* Metabolic syndrome/diabetes
* Osteoporosis
* Depression
* Anxiety
* Lung cancer.
85
What is dyspnea?
Subjective sensation of uncomfortable breathing.
86
What characterizes severe dyspnea?
* Flaring of the nostrils
* Use of accessory muscles of respiration
* Retraction of the intercostal spaces.
87
Define chronic cough.
A cough that lasts longer than 3 weeks.
88
What is sputum production and why is it significant?
Changes in amount, consistency, colour, and odour provide information about disease progression and therapy effectiveness.
89
What is hypercapnia?
Increased carbon dioxide (CO2) in the arterial blood, with CO2 level > 45 mmHg.
90
What is hypoxemia?
PaO2 < 80 mmHg blood gas oxygen level.
91
What is the significance of FEV1 in pulmonary function tests?
It measures forced expiratory volume in one second.
92
What does a postbronchodilator FEV1/FVC <0.70 indicate?
Airflow limitation.
93
What is the main treatment strategy for COPD patients?
Smoking cessation.
94
What vaccinations are recommended for COPD patients over 65 years of age?
* Influenza vaccination
* Pneumococcal vaccinations (PCV13 and PPSV23).
95
What are the types of short-acting bronchodilators used in COPD?
* SABA (short-acting inhaled beta-agonists)
* SAMA (short-acting muscarinic antagonists).
96
What is the purpose of pulmonary rehabilitation in COPD?
To reduce frequency and severity of exacerbations, improve exercise tolerance and health status.
97
What is the role of alpha 1-antitrypsin in lung health?
It inhibits proteases and protects tissues from neutrophil elastase.
98
What is the clinical manifestation of chronic bronchitis?
Recurrent or chronic productive cough for a minimum of 3 months for 2 consecutive years.
99
What is the impact of smoking cessation on COPD?
It has the greatest capacity to influence the natural history of COPD.
100
What are the characteristics of cor pulmonale?
Right ventricular enlargement due to chronic pressure overload.
101
What defines a COPD exacerbation?
An acute worsening of respiratory symptoms that results in additional therapy.
102
What is the significance of the modified Medical Research Council (mMRC) dyspnea questionnaire?
It helps to determine the severity of dyspnea in COPD patients.
103
Fill in the blank: The airflow resistance is significantly increased in _______.
Emphysema.
104
True or False: COPD is completely reversible.
False.
105
What is the use of spirometry in COPD?
To assess lung function and diagnose lung disease.
