Respiratory System Flashcards
Function of pulmonary ventilation
Breathing. Promotes air movement in and out of the lungs.
Function of external respiration
Gas exchange at the alveoli and pulmonary capillary interface. Loading of O2, unloading of CO2.
Process of respiratory gas transport
O2 and CO2 transportation from and to the lungs and body cells via blood in the circulatory system.
Process of internal respiration
Gas exchange at the interface between systemic capillaries and tissue cells.
Definition of Type I respiratory failure. SpO2 and SpCO2 values
Hypoxaemia with normocapnia
(PaO2 low, PaCO2 normal/low)
Causing an increased alveolar gradient
Definition of Type II respiratory failure, SpO2 and SpCO2 values. Target SpO2.
Hypoxaemia with hypercapnia (Low PaO2 with high PaCO2) Normal alveolar gradient Decreased pH. SpO2 88-92%.
Tachypnoea definition
RR >20rpm.
Bradypnoea definition
RR <12rpm.
Apnoea definition
Absence of respiration
Cyanosis definition
Lack of oxygen in the blood that causes bluish discolouration of skin and mucous membranes
Hypoxia definition
Inadequate oxygen supply to the tissues
Dyspnoea definition
Difficult, laboured breathing
Hypoxaemia definition and value
Reduced arterial blood PaO2 <8kPa, with or without increased arterial PaO2.
Hypercapnia definition and value
Increased arterial PaCO2 >6kPa.
Definition of SaO2
Percentage of haemoglobin saturated with oxygen. Arterial SaO2 very similar to capillary SpO2 measures
SpO2 definition and target value.
Peripheral capillary blood haemoglobin oxygen saturation (not a measure of effective ventilation). SpO2 94-98%
PaO2 definition and normal values
Partial pressure of oxygen in the arterial system. Normal values 11-13kPa
Normal haemoglobin value
11.5-18.0g/dL
Arterial blood gas (ABG) analysis normal values with unit of measure: pH PaO2 PaCO2 HCO3- BE SaO2 Lactate
pH: 7.35-7.45 PaO2: 11-13.3kPa PaCO2: 4.8-6.0kPa HCO3-: 21-28mmol/L BE: -2 to +2 SaO2: 95-100% Lactate: 0.5-1mmol/L
PaCO2 normal values
4.6-6.0kPa
What occurs in respiratory acidosis
Increasing PaCO2 with decrease PaO2 causing decrease in pH
Compensatory mechanisms for respiratory acidosis
Increased respiratory rate. Depletion of HCO3- store/increase in circulating HCO3-
What is pink throthy sputum a sign of
Cardiac failure
Definition of chenye-stokes respiration
Irregular breathing pattern with periods of apnoea associated with brain stem death.
What is Kussmal breathing and what is it associated with? What may cause it?
Deep and rapid breathing associated with metabolic acidosis. Caused by sepsis, uraemia or diabetic ketoacidosis
Flail chest
Breaking of ribs away from chest wall, preventing normal mechanics of breathing from occurring efficiently.
Surgical emphysema
Air under the surface of the skin on the chest from the lungs, feels like bubble wrap.
What can an X-ray of the chest help to diagnose in relation to the respiratory system
Pneumothorax, pleural fluid, pulmonary oedema, infection, lung fibrosis.
What occurs in respiratory alkalosis?
Decrease CO2
Increase in pH
What is base excess?
Provides a numerical value for the the degree of acid base imbalance.
What does a BE of +2 mean?
Increase in bicarbonate due to metabolic alkalosis causing compensatory respiratory acidosis to try and bring pH back within range
What does a BE of -2 mean?
Reduced bicarbonate due to metabolic acidosis causing compensatory respiratory alkalosis to bring pH back within range.
What type of process is inspiration/expiration
Inspiration= active process Expiration= passive
What determines airway resistance?
Diameter of airway
What is lung compliance?
Ability of lungs to stretch and expand easily.
What is the name of the membrane that covers the lung and chest wall?
Pleura (visceral and parietal)
What keeps the visceral and parietal pleura together?
Negative pressure within the inter plueural space that constantly pulls the two membranes together.
What is the costal angle?
Space/angle between the two sides of the rib cage by the diaphragm.
What is the function of bronchial circulation?
Supply oxygen and nutrients to the lung parenchyma, airways, pulmonary arteries/veins and pleura