Wk 2

Question 1

External respiration

Answer 1

Exchange of gases between the alveoli of lungs and pulmonary blood capillaries
Results in conversion of deoxygenated blood from heart to oxygenated blood returning to heart
Affected by altitude
Nit all alveoli are supplied with blood at any one time (referred to as VQ match)

Question 2

Physiology of external respiration: inhalation

Answer 2

Oxygen
Inspiration
Alveoli
O2 diffuses across
Pulmonary capillaries
Blood oxygenated
Heart left ventricle

Question 3

Physiology of external respiration: exhalation

Answer 3

Heart right ventricles
De oxygenated blood
Pulmonary capillaries
CO2 diffuses across
Alveoli
Expiration
CO2

Question 4

Internal reputation

Answer 4

Exchange of O2 and co2 between systemic blood capillaries and tissue cells
Conversion of O2 blood to de02 blood
Reliant upon diffusion gradient
Only around 25% O2 in blood is needed under normal circumstances

Question 5

Internal respiration flow diagram

Answer 5

Oxygenated blood
Tissue capillaries
Diffuses through interstitial fluid
Tissue cells

Opposite for CO2

Question 6

Oxygen transport

Answer 6

97% O2 transported bound to hameoglobin
Haem has 4 binding sites
All sites occupied = full saturation
Factors affecting O2 include: temp, harem levels, pH, paO2

Question 7

Respiratory disorders

Answer 7

COPD
Asthma
Pneumonia

Question 8

Assessment of breathless patient

Answer 8

Establish ABC
Results in low levels of O2 in blood (hypoxaemia) and thus low levels of O2 in tissues (hypoxia)
Colour
Conscious level
Facial expressions, posture
Look, listen feel: depth rate of breaths, accessory muscles, chest movement and expansion
Air entry: bilateral breath sounds, type of sound,
O2 sats, blood gases

Question 9

Types of breathing patterns

Answer 9

Tachypnoea: first indication of resp distress, rapid rate of breathing greater than 20bpm

Bradypnoea: slow rate of breathing less than 12 bpm, deterioration in patient, fatigue, hypothermia, CNS depression, drugs such as opiates

Orthopnoea: must stand or sit upright to breathe properly. Asthma, pulmonary oedema, emphysema

Cheyne-stokes: period of apnoea alternate with periods of hyperpnoea, end stage of life

Kussmaul breathing: air hunger, deep rapid breaths due to stimulation of resp centre in brain caused by metabolic acidosis

Question 10

Work of breathing

Answer 10

Doesn’t demand the bodies energy stores to contribute

Increase resps requires increased energy

Question 11

Identifying respiratory distress

Answer 11

Increased resp rates
Increase HR

Sweating
Use of secondary muscles
Exhaustion
Cyanosis
Flared nostrils
Wheeze from bro how constriction

Question 12

Peripheral vs central cyanosis

Answer 12

Peripheral: inadequate O2ation of circulating blood, extremities appear blue, poor perfusion, tongue and lips pink
Central: systemic shortage of O2, arterial O2 below 85%, at risk of cardiac arrest, cause include pneumonia, acute severe asthma, PE, pulmonary oedema

Question 13

Arterial blood gases

Answer 13

Info about patients gas carrying ability and their metabolic and resp status
Measure 
pH (7.35-7.45)
Base excess BE (-2-2mmol)
Bicarbonate HCO3 (22-26mmol)
Partial pressure of CO2 (35-45)
Partial pressure of O2  (80-100mmHg)

Question 14

Hypo ventilation

Answer 14

Raised levels of CO2 (PaCO2) in blood cause severe problems due to acidity
Cause: airway obstruction, CNS depressant drugs, peripheral neuromuscular disease, exhaustion
Tx: 100% humidified O2 increase sat over 90%
Provide assisted ventilation
Reverse CNS drug induced depression
Specialist help

Question 15

VQ mismatch

Answer 15

Some problems affecting the amount of air or blood supply reaching the lungs include: ventilation decrease in relation to blood flow, blood flow reduced compared to ventilation.

Low VQ: shunt perfusion (alveoli perfused but not ventilated) ET tube in mainstream bronchus
High VQ: dead space ventilation (alveoli ventilated but not perfused) cardiac arrest

Frequent patient response is hyperventilation which has knock in effect of increasing WOB and CO2

Question 16

Normal airway protection

Answer 16

Epiglottis
Glottic closure reflex
Laryngospasm 
Cough reflex
Apnoea reflex

Question 17

Simple airway management strategies

Answer 17

Head tilt and chin lift
Jaw thrust
Recovery position or side lying
Oral suction

Question 18

Airway adjuncts

Answer 18

Oropharyngeal airway:
Nasopharyngeal
Bag-valve-mask ventilation

Question 19

O2 and Co2 retention in COPD

Answer 19

Two effects in COPD:
Hypoxic pulmonary vasoconstriction - allows blood to bypass hypoxic alveoli and improve gas exchange
Haldane effect - deoxygenated blood binds CO2 to hameoglobin
Want to reduce the risk of oxygen induced hypercapnia

Question 20

Oxygen delivery systems

Answer 20

Nasal cannula: 2-6L 24-35%
Simple face mask: 5-12L 24-60%
Non rebreather/reservoir mask: 10-15L >60%

Question 21

Fixed performance mask

Answer 21

Provide sufficient flow of gas to meet the needs of the patients minute ventilation
% of O2 determined by flow rate not by patients resp rate
Venturi mask is example

Question 22

High flow oxygen

Answer 22

Large volumes of gas not always a high conc
Aim to meet peak inspiration flow
Indications: cardiac or resp arrest, acute resp distress, hypotension, asthma, pulmonary embolism

Question 23

Monitoring 02 therapy

Answer 23

Colour
RR
Respiratory pattern
Visual verbal and vital signs of respiratory distress

Question 24

Other consideration when providing o2

Answer 24

Stopping o2 Tx: normal pH, normal blood gases, sats over 94% on RA
Humidification: o2 flow rates greater than 6L, intubation, tracheostomy
Nebulise

Question 25

Mechanics of breathing

Answer 25

Controlled by resp centre in brain stem. Relies on chemical and neurological input.

Inspiration: moves air into lungs, negative pressure increases lung volume, diaphragm and external intercostals contract,

Expiration: air moves out, positive pressure, passive, elastic recoil, surfactant important