Respiratory System and Conditions

How is the respiratory system split and what makes up each of the parts?

Upper and Lower, and Conducting and Respiratory portion.

Upper: warms, moistens and filters. Includes nasal cavity, nose, larynx, pharynx, epiglottis.

Lower: responsible for external respiration. Includes trachea, lungs (including bronchus, bronchioles, alveoli), diaphragm

Conducting portion: Includes all cavities and tubes starting at mouth and ending at terminal bronchioles (before alveoli branch off) . Warms, moistens, filters air to lungs and back out.

Respiratory portion: Tissues inside the lungs that do gas exchange. Includes respiratory bronchioles, alveolar ducts and sacs, alveoli. Where gas exchange occurs between air and blood.

Describe the physiology of respiration and the three steps

The process of gas exchange in the body

Pulmonary ventilation (the balloon principle): Moving air in and out of body. Inspiration occurs when the diaphragm contracts and flattens (75% of work) and intercostal muscles contract (pull) chest wall (25% of work), allowing lung volume to increase and pressure to decrease (Boyle's law). Air flows in. As diaphragm and intercostal muscles relax (passive), volume of thoracic cavity decreases, air leaves lungs.

External respiration: Exchange of gases between alveoli of lungs and blood inside pulmonary capillaries

Internal respiration: Exchange of gases between the blood inside pulmonary capillaries around body and tissue cells

Explain how gas exchange works

Gases move from areas of high pressure to low. Each gas acts independently of others.

Oxygen moves from an area of higher O2 pressure in the alveoli to an area of lower O2 pressure in the pulmonary circulation.

This process is known as diffusion (movement of molecules from an area of higher concentration to lower concentration until both areas have the same concentration.

In the pulmonary circulation, carbon dioxide has a higher partial pressure so moves across the alveoli where it can be expires.

In this way, oxygen is taken up by the body and carbon dioxide is removed.

Describe the two ways in which respiration are controlled

Voluntary respiration: Originates in the cerebral cortex, and is the body's conscious breathing effort (e.g. holding breath, playing an instrument etc) Autonomic respiration: Originates in the respiratory centre within the medulla oblongata. Controls rhythmic breathing via phrenic and intercostal nerves. Expiratory neurons generally become active only during forceful breathing, such as when exercising.

Describe the position of the lungs in the body

Extend from the diaphragm to just above the clavicles. Separated by the mediastinum which contains the heart, major vessels, oesophagus and trachea.

Describe the anatomy of the lungs

The lungs are covered by the pleura (2 layers and a space)

• Parietal pleura - attached to the chest wall
• Visceral pleura - covers the lungs
• Pleural cavity - fluid filled space between lungs which prevents friction during breathing

Left lung - made up of two lobes (upper and lower), is smaller than the R lung. Right lung - made up of three lobes (upper, middle and lower) Lobes are separated by fissures. Each lobe has its own secondary bronchus branch.

The trachea branches off into the left and right bronchus (supplying L and R lung), then into secondary and tertiary bronchi, then into terminal bronchioles, then respiratory bronchioles, then into alveolar ducts, alveolar sacs, then alveoli.

Describe Alveoli

Cute shaped pouches with very thin walls allowing gas exchange via a large surface area.

Describe the approach for Auscultation

Auscultation is the listening of sounds in the body, most commonly with a stethoscope.

You should auscultate working left to right to left again, back and forth in 6 spots on both the front and back. Press firmly and compare either side. Landmarks on the back include 6 on either side of the spine, and 2 under the shoulder blades. Landmarks on the front include 1 above each of the clavicles, three spots down along the chest and one on either side of the lateral portion of either side of the body.

What are the three categories of breathlessness?

Acute: suddenly or in minutes Subacute: over hours or days Chronic: weeks/months

How do you take a Resp rate and what is the normal adult resp rate?

Watch for chest rise and fall, measured over one minute. Can assist by placing a hand on their back or chest. Try to avoid telling your patient as they may subconsciously alter their breathing.

Normal adult resp rate range is between 12-20.

What is the ideal range for oxygen saturations in a normal healthy patient

Above 94%

What is the normal O2 saturation range for a pat with COPD?

88-92%

What is peak flow expiratory flow rate (PEFR) and how is it measured?

Peak flow is a measurement of how quickly you can breathe air out of your lungs, measured using a peak flow meter.

Explain the procedure, set to zero, get pat to hold level and exhale forcefully and quickly as much as they can. take 3 measurements and record the best. Compare on JRCALC with average for height and age. Asthma/COPD pat's may know their normal PEFR.

What is COPD, how is it diagnosed and what are the two most common diseases related to COPD?

Chronic Obstructive Pulmonary Disease (COPD) includes a range of illnesses that result in airflow obstruction. It is progressive and not fully reversible.

The two most common are chronic bronchitis and emphysema.

Diagnosed by cough and sputum production for at least 3 months in 2 consecutive years.

Describe Chronic Bronchitis, its signs and symptoms, and management.

Inflammation and increased mucus production in the bronchi/bronchioles narrows the airways, caused from long term infection and lung damage. Smoking is a huge factor affecting chronic bronchitis.

Signs and symptoms: productive cough, dyspnoea, cyanosis, tachycardia/pnoea, accessory muscle use, high BP, reduced 02, wheeze on auscultation, slow capillary refill, oedema, reduced level of consciousness/hypoxia (extreme cases)

Management: Full history, Resp assessment, Limit O2 to 6 mins on/6 mins off, position for comfort, ask about individual care plan, baseline obs and monitor

Describe Emphysema, its signs and symptoms, and management

Distension and destruction of alveoli by enzymes called proteases, which are normally kept under control by ant-proteases enzymes but smoking for example upsets this balance. Alveoli collapse, obstructing airway, and blister like air pockets can form (bullae).

Signs and symptoms: barrel chest (air trapped due to obstruction and ribs expand), pursed lips on expiration, productive cough, dyspnoea, tachycardia/pnoea, accessory muscle use, high BP, reduced 02, wheeze on auscultation, slow capillary refill, oedema, reduced level of consciousness/hypoxia (extreme cases)

Management: Full history, Resp assessment, Limit O2 to 6 mins on/6 mins off, position for comfort, ask about individual care plan, baseline obs and monitor

Describe chest infections, signs and symptoms, and management

An infection of the lungs. Main types are Acute Bronchitis and Pneumonia.

Most bronchitis cases are caused by viruses. Most pneumonia cases are caused by bacteria. Can cause fluid buildup in lungs (consolidation), sounds like crackles

Susceptible people include the extremes of age, overweight, pregnant, immunocompromised, smokers, and others with long term health conditions

Signs and symptoms: Persistent cough, yellow/green phlegm or haemoptysis, breathlessness, dyspnoea, febrile, tachycardia, pleuritic cp or tightness, confusion or disorientation

Management: full resp assessment, establish airway, if red flags pre alert, abs, 12 lead, consider o2

Describe Asthma, its signs and symptoms, and management

Caused by irritation of lower airway and immune response producing mucus, tightening muscles around bronchi, and swelling bronchi. Obstruction overcome by inspiration but expiration delayed by narrowing of the airway. Categorised as mild, moderate, severe and life threatening. Triggers may be cold, allergies, particulates in air, exercise.

Signs and symptoms: Wheeze on expiration, tachypnoea, tachycardia, cyanoses, exhaustion, altered level of cons, arrhythmia, hypotension, dib, cannot complete full sentence, accessory muscle use, silent chest

Management: full history (prev ED or ICU attendance, annual asthma review, med compliance), analysis of triggers, full respiratory assessment, oxygen treatment, bronchodilators, PEFR (if mild-moderate).

Describe pulmonary embolism, its signs and symptoms, and management

Obstruction of pulmonary vessels causing lung tissue death. Most common cause is a DVT, where a clot breaks off and travels via femoral and iliac veins through heart and into pulmonary vessels. Commonly misdiagnosed as panic attack.

High risk factors: surgery, trauma, disabilities affecting mobility, long flights, bed bound pats.

Signs and symptoms: Dys/tachypnoea, Tachycardia, Pleuritic CP, TLOC/syncope, cough/haemoptysis, pain worse on inhalation/stabbing pain, pain/thrombus in calf,

Differentials: pleurisy, pneumothorax, cardiac CP

Management: swift transport to hospital, ABCs, position of comfort, provide O2 of required, be prepared for cardiac arrest

Describe the structure of the trachea

Approx 12-15 cm long in adult, consists of C shaped cartilages, posteriorly completed by trachealis muscle. Extends from cricoid cartilage to sixth thoracic vertebra where it splits to L and R bronchus.