Respiratory case Flashcards
functions of the respiratory system? (4)
- Gas exchange
- Filtering particle matter
- Defense against inhaled particles and pathogens
- Processing of endogenous compounds by the pulmonary vasculature
Emergency assessment: A B C D E F
AIRWAY BREATHING CIRCULATION DISABILITY EXPOSURE don't ever FORGET to measure blood glucose
Emergency assessment: BREATHING
- What to do:
- Normal:
- Tachypnoea:
- Apnoea:
- Count the number of breaths per minute
- Normal: 10-15 breaths per min
- Tachypnoea: rapid breathing rate
- Apnoea: breathing arrest
Emergency assessment: Look for
- Abnormal blue-purple discolouration of the mucus membranes particularly the tongue
- Abnormal patterns of breathing
Abnormal breathing patterns:
- Keyne-stokes:
- Kussmaul:
- Cheyne-Stokes: often occurs towards the end of life.
- Fast shallow breathing followed by slow deep breathing
- Kussmaul breathing: indicates increased acidity of arterial blood (e.g. diabetic ketoacidosis)
- Deep, rapid and laboured breathing
Auscultating: listening to the breath sounds using a stethoscope
- Normal sounds
- Abnormal sounds
- Normal sounds are known as vesicular
- Abnormal sounds include; wheeze, stridor and bronchial breathing
Abnormal auscultation sounds: stridor
- High-pitched, musical breathing sound
- Caused by a blockage in throat or larynx
Abnormal auscultation sounds: bronchial breathing
- Loud, harsh breathing sounds. Midrange pitch
Hypoxia definition:
- Inadequate oxygen supply to maintain homeostasis in tissues
Hypercapnia:
- Increased arterial pressure of CO2 (PaCO2)
Normal blood oxygen saturation (SaO2):
- 95-100% saturation
Nasopharynx function: (2)
- Function
- Protective reflex
- Warms, humidifies and filters air
- Sneezing is a protective reflex
Laryngeal function: (3)
- Phonation
- Closing the airway during swallowing
- Cough reflex
dead space:
- Volume of gas in respiratory tract that is not involved in gas exchange
- Physiological
- Anatomical
Physiological dead space:
- Anatomical deadspace plus the volume of gas in alveoli that have inadequate perfusion
Anatomical deadspace:
- Volume of gas in upper airways and the conducting zone of the airways
Closing capacity:
- Definition
- Age
- Equation
- Maximal lung volume where airway closure can be detected in the lungs during expiration
- Increases with age
- CC = CV + RV
Factors affecting airways resistance: (2)
- Contraction of bronchial smooth muscle
- Closing capacity
Control of bronchial smooth muscle: neural pathways
- Parasympathetic:
- Sympathetic:
- Postganglionic parasympathetic fibres release acetylcholine, agonising M3 muscarinic receptors
- Causes bronchoconstriction
- NANC: bronchodilator
Control of bronchial smooth muscle: humoral control
- Elevated adrenaline levels in blood agonise beta2-adrenoceptor
- Causes bronchodilation
Control of bronchial smooth muscle:
- Physical effects
- Chemical effects
- stimulation of the respiratory epithelium can cause bronchoconstriction (cold air, dust, smoke)
- Gastric acid aspiration and gas inhalation cause bronchoconstriction
Control of bronchial smooth muscle: local cellular mechanisms
- Inflammatory cells in the lungs (mast cells) may be activated by pathogens or allergens
- Causes bronchoconstriction
Flow/volume loop measured using a spirometer:
- Starts at residual volume (RV)
- Inhales to fill lungs to Total Lung Capacity (TLC)
- Maximum effort to exhale to achieve Peak Expiratory Flow (PEF)
Terminology:
- Ventilation (V)
- Perfusion (Q)
- Minute volume (VE)
- Alveolar ventilation (VA)
- V: refers to the flow of respiratory gases
- Q: the flow of blood
- VE: tidal volume volume of gas exhaled in one minute
- VA: the amount of fresh gas delivered to the alveoli per minute