Respiratory System

Question 1

Anatomy of upper and lower respiratory tracts

Answer 1

Upper

Nasal turbinates 
Nares
Epiglottis 
Larynx 
Oesophagus 

Lower

Trachea
Carina
Primary bronchus 
Bronchiole 
Lower lobe
Diaphragm

Question 2

Anatomy of lower respiratory tract

Answer 2

Trachea

Cartilage rings
Primary bronchus 
Root of lung
Visceral pleura
Cartilage plates 
Secondary bronchus 
Tertiary bronchi
Smaller bronchi
Bronchioles 
Terminal bronchiole
Respiratory bronchiole 
Alveoli

Question 3

Anatomy of terminal airways and alveoli

Answer 3

Microscopic air tube

Microscopic blood vessels

Capillaries

Alveoli

Question 4

Breathing and respiratory

Answer 4

External respiration- is what we call breathing - this occurs in the lungs where oxygen diffuses into the blood and carbon dioxide diffuses into the alveolar air

Internal respiratory occurs in the metabolising tissues, where oxygen diffuses out of the blood into the tissues and carbon dioxide diffuses out of the cells and into the blood

Question 5

Respiratory processes

Answer 5

Neural control - respiratory centres in the brain control inspiration rate and death

Ventilation - air entry to lungs

Perfusion - blood supply to the lungs

Diffusion - oxygen tea spot to RBCs

Question 6

Why do we need oxygen

Answer 6

Oxidative phosphorylation:
- adenosine triphosphate (ATP) is the universal energy source of cells to facilitate all chemical processes in cells

• ATP is produced through a series of chemical reactions in the inner compartments of mitochondria, the final stages of which require oxygen

The body presses 90 seconds supply of ATP therefore it is necessary to breathe continuously in order to supply enough oxygen for the on going generation of ATP

Question 7

Tissue viability in anoxia

Answer 7

Brain cell death= 4-5 mins

Myocardium = 5 mins

Kidneys and liver = 10 mins

Skeletal muscle= 2 hours

Question 8

Anatomical differences

Answer 8

As compared to an adult a child has

A relatively large occiput = flexion of the neck can cause partial obstruction

A relatively large tongue = potential for obstruction

Changing dentition over time = no teeth/ milk teeth/ adult teeth/ loose teeth can be inhaled

Obligatory nose breathers under 6 months of age, risk of apnoea with nasal blockage

Question 9

Anatomical differences

Answer 9

Narrow nasal passage= smaller airways = greater resistance to airflow, exacerbated by any secretions

Frequently enlarged tonsils/ adenoids= increased resistance to airflow and potential obstruction

Sharp angle between orophayrnx and glottis = enables young babies to breath and feed at the same time

Question 10

Anatomical differences

Answer 10

Smaller airways diameter= any obstruction/ inflammation causes greater resistance to flow and so more sever distress ( infants are extremely vulnerable to atelectasis and exploratory wheeze)

Airway walls that are less rigid = tendency to collapse when in distress giving greater resistance to air flow

Thicker alveoli walls at birth = decreases the efficiency of gas exchange

Question 11

Anatomical differences

Answer 11

Fewer alveolar numbers (alveolar clusters develop over the first 8 years of life) less efficient gas exchange

Ribs that are more horizontal = lessening the chest wall movement and tidal volume

Rib cartilage that is more compliant = less outward recoil and tidal volume

Weaker intercostal muscles = less able to lift the rib cage up and forward and so tidal volume decreases

Question 12

Surfactant

Answer 12

Action of surfactant

• reduces water surface tension
• prevents collapse on expiration

Produced by type 2 alveolar pneumocystis

• 22-24 weeks production begins
• 32-36 weeks sufficient concentration present

Production of surfactant is induced by

• glucocorticoids eg cortisol
• catechilamines eg adrenaline

Question 13

Acute respiratory failure

Answer 13

An acute clinical situation in which alveolar ventilation fails to maintain arterial blood gasses at physiological values

NB there may be acute respiratory failure on top of existing chronic respiratory failure

Question 14

Cause of acute respiratory failure

Answer 14

Drug overdose, spinal cord injuries, stroke

Trauma, injury affecting ribs and or lungs

Infection, pneumonia, croup, epiglottitis, bronchiole ‘tis

Airway obstruction, foreign body, asthma, allergic reaction

Burns inhalation of hot or corrosive fumes

Question 15

Vulnerability to respiratory tract infections in children

Answer 15

At birth

• immunologically immature
• has benefit of placental transfer of maternal IgG and IgA

First six months
-anatomical risk eg narrower bronchial tree
-environmental risk include
Exposure to tobacco smoke
Formula feeding- on immunological advantages
Child care/siblings - infection
Poor socio-economic status and housing

Vulnerability persists, but to a lesser degree during first 7-8years of life

Question 16

Clinical assessment of ARF

Answer 16

Clinical signs and symptoms of ARF include

Confusion, sleeping and loss of consciousness

Dyspnoea- subject sensation of difficult or laboured breathing air hunger, shortness of breath, feeling like you can’t get enough air

Cyanosis- bluish colour on your skin, lips, and fingernails

Increased work of breathing

Question 17

Clinical assessment of ARF

Answer 17

Signs of increase work of breathing include

Tachypnoea

Intercostal and subcostal recession

Use of accessory muscles

Wheezing

Tachycardia

Sweating

Head bobbing, nasal flaring and grunting in young babies

Question 18

Cyanosis

Answer 18

Blueness of the skin and mucous membranes caused by excessive deoxygenation of Hb in the capillaries

Question 19

Immediate management

Answer 19

Aims of immediate management are

Restore effective alveolar ventilation by

• supplemental O2
• optimal position of patient
• remove any visible airway obstruction
• intubation

Identify and treat underlying cause

Instigate mechanical ventilation if clinically indicated - will require ITU admission

Question 20

Summary

Answer 20

Children are susceptible to respiratory problems due to their unique anatomy

Additionally children are vulnerable to RTI due to their immature immune system

Assessment of a child for signs and symptoms of respiratory distress is an important skill for all nurses to develop , as well as identifying when to instigate interventions

Question 21

What is asthma

Answer 21

Asthma is a long term condition that results in inflammation and episodic narrowing of the lower airways

This narrowing of airways results in an increased resistance to airflow, and this gives rise to symptoms that include breathlessness, tightness in the chest, coughing and wheezing

Question 22

Aetiology of asthma

Answer 22

Asthma is thought to arise as a result of a combination of genetic sesceptibility and early exposure to environmental-allergens

Around 60% of all asthma cases are hereditary- if a person has a parent with asthma, they are 3 to 6 times more likely to develop asthma than someone who does not have a parent with asthma

Stops- asthma is often found as part of a triad of eczema, asthma and hay fever. And this is referred to as atopy this runs in families

Question 23

Three key features of asthma

Answer 23

Asthma is chronic respiratory condition leading to

Airway inflammation

• medium and small airways
• mucosal oedema and mucus secretion

Intermittent airflow obstruction
-airway smooth muscle contraction/ construction

Bronchial hyper-responsiveness to triggers
-smoke, pets, exercise, weather, infections, dust, mould, pollen, emotions

Question 24

Asthma

Answer 24

Environmental factors-genetic predisposition

Bronchial inflammation

Bronchial hyper/reactivity and trigger factors

Oedema
Bronchi constriction
Increased mucus production

Airways narrowing

Cough, wheeze, breathlessness, tightness I gotta the chest

Question 25

Pathology of asthma

Answer 25

Hyperinflated alveoli Constricted smooth muscles Degranulation of mast cells Mucus accumulation Thick mucus plugs

Question 26

Features in chronic asthma and

Answer 26

In long term asthma the flow long airway remodelling or change in the airways are seen . Fibrosis .increased number and size of mucous- producing cells .hypertrophy of smooth muscle and increased vascularisation When these are present they are markers of persistent symptoms and resistance to treatment

Question 27

Making a diagnosis of asthma

Answer 27

Asthma is a clinical diagnosis starting with the history and examination A single wheezy episode is not asthma Reaching a diagnosis can take weeks, months or every years, particularly in a young child During this time the child may have a trial of treatment and test to help arrive at a diagnosis This can be frustrating and worrying time for parents

Question 28

Features suggestive of asthma

Answer 28

Persistent/ recurrent symptoms that include nocturnal cough, wheeze, cough, breathlessness Symptom-free intervals Coughing after exercise and or with crying/ laughing Variable reduction of airway function e.g measured by peak exploratory flow Family history of atopy/ asthma Good response to asthma drug treatment

Question 29

Potential trigger factors

Answer 29

Acute asthmatic episodes may be triggered by Viral infections Inhaled allergens e.g house dust mite, car dander Environmental pollution Exercise Specific foods Psychological stress

Question 30

Wheezing

Answer 30

Wheezing is defined as A continuous, high pitched musical sound coming from the chest it must be distinguished from other respiratory sounds In general the earlier the onset of wheeze, the better the prognosis

Question 31

Asthma attack

Answer 31

The sudden onset of breathing difficulty is described as an asthma attack During such an attack breathing becomes increasingly difficult, the child can become tried due to the work of breathing They may given an account of having benefited from their in healers or from exhaling through pursed lips The child may also describe their chest as feeling tight

Question 32

Acute asthma getting worse

Answer 32

Look out for the child who Can’t complete sentences in one breath Is too breathless to talk Is tiring Is using their accessory muscles Has a low pulse oximetry reading Is breathing very fast - 40/minute in under 5 years - 50/minute in under 5s Has a fast heart rate - 120/minute in under 5years - 130/minute in 2-5 years old Has a low peak flow -50% of predicted best

Question 33

Peak flow

Answer 33

A simple measurement of how quickly you can blow air out of your lungs A rate of flow not volume of air Measured in litres per minute L/min Important in monitoring asthma, ideally as part of an individualised action plan flagging when to seek a medication review It is probably less helpful in an acute attack as technique may be suboptimal and it may exacerbate the attack

Question 34

Peak exploratory vs high in children

Answer 34

Taller the child the high the peak flow of

Question 35

Pharmacotherapeutics

Answer 35

Relievers: Used to rapidly reverse bronchi construction and associated symptoms Preventers Take daily on a long term basis to control presistent asthma Emergency drinks Used in for severe life threatening asthma

Question 36

The treatment of asthma

Answer 36

Medications are designed to interfere with the various areas of the pathology seen in asthma Smooth muscle contraction Inflammation Children with a high probability of asthma are started on a diagnostic trial of treatment The recommended guideline for children adopts a stepwise approach

Question 37

Step wise approach

Answer 37

Regular prevention -very low dose ICS Initial add on preventers - very low dose ICS - add inhaled LABA Additional add on therapies - no response to LABA-stop LABA and increase does of ICS to low does - if benefit from LABA but control still inadequate - continue LABA and increase ICS to low does - If Benidorm from LABA but control still inadequate - continue LABA and ICS and consider trial of other therapy High dose therapies - consider trials of - increasing inhaled corticosteroids up to medium does - addition of a fourth drug- SLow release Theophilline

Question 38

Questions

Answer 38

Will my child grow out of it - boys are more likely than girls to grow out of asthma - children with asthma, particularly of severe asthma, never outgrow it Does avoidance of allergens reduce the severity of asthma - where there is a history of symptom exacerbation or testing shows sensitisation to an allergen then yes Does smoking cause asthma -second hand slime is well know to cause asthma Breasting and asthma - breastfeeding is associated with a reduced risk of developing childhood asthma

Question 39

Summary

Answer 39

A chronic inflammatory disorder of the airways The inflammation leads to wheezing, breathlessness, tightness in the chest, cough Widespread but variable obstruction to airflow Increase in bronchial sensitivity Many cellular elements play a role: mast cells, eosinphils, T- cells, macrophages, neutrophils and epithelial cells Pharmacotherapeutic management needs regular review for optimum control

Question 40

Lesson summary

Answer 40

An understanding of normal anatomy and