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Adsorption
The moving/ migration of molecules of DPPC from aqueous hypophase
to surface layer.
Air leak
When the air sacs become overfilled with air, and air gets
into spaces where it should not be. Air leaks include pneumothorax,
pneumomediastinum and pulmonary interstitial emphysema (PIE).
Airway resistance
The ratio of pressure difference between the mouth, nose or
other airway opening and alveoli to the simultaneously measured
resulting volumetric gas flow rate.
Alveoli (air sacs)
Small pouches at the very end of the bronchial tree.
Alveolar-air interface
The point where gas exchange takes place between alveolar
air and pulmonary capillary blood.
Amino acid
A group of simple organic compounds, many occurring naturally
in plant and animal tissues, forming the basic constituents
of proteins.
Anaemia
Low red blood cell count or deficiency.
Apnoea
Absence or cessation of spontaneous breathing.
Asphyxia
Severe lack of oxygen leading to loss of consciousness and,
if not corrected, death.
Atelectasis
Collapse of lung tissue, preventing the respiratory exchange
of carbon dioxide and oxygen.
Auscultation
The act of listening to sounds from the heart, lungs etc.
as part of medical diagnosis.
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Barotrauma
Physical injury sustained as a result of increased environmental
pressure.
Bronchopulmonary dysplasia (BPD)
A form of long-lasting lung disease which can be diagnosed
if the baby is 28 days old, is still in oxygen and has appropriate
x-ray changes. It may also be referred to as chronic lung
disease.
Bradycardia
A slowing of the heart rate.
Bronchi
A series of branch like structures in the lung which branch
off the trachea.
Bronchospasm
an abnormal contraction of the smooth muscle of the bronchi,
resulting in acute narrowing and obstruction of the respiratory
airway.
Bronchioles
Small airways of the respiratory system extending from the
bronchi into the lobes of the lung.
Bronchiolar cells
Cells found in the small airways extending from the bronchi
into the lobes of the lung.
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Carbohydrates
Energy-producing organic compounds containing carbon, hydrogen
and oxygen e.g. starch, glucose and other sugars.
Chromatography
A process which separates and/or analyses gases or dissolved
chemical materials.
Chronic lung disease
(CLD)
Can be defined as oxygen dependency at 28 days or 36 weeks
post-conceptional age, with abnormal chest x-rays. This condition
is more correctly known as bronchopulmonary dysplasia.
Column chromatography
The process of separating and analysing substances according
to their absorption affinities.
Congenital
An anomaly or defect resulting from a problem with development
of an organ or body tissue in the fetus.
Congenital heart
disease (CHD)
Heart disease resulting from the abnormal development of the
heart.
Cyanosis
Bluish discolouration of the skin and mucous membranes caused
by an excess of deoxygenated haemoglobin.
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Dead space (anatomical)
The space in the conducting zone of the airways that does
not exchange with the blood.
Dead space (physiological)
The total volume of gas not equilibrating with blood.
Desaturation
Falling levels of blood oxygen.
Dipalmitoyl phosphatidylcholine
(DPPC)
Makes up 70-75% of phosphatidylcholine, the main phospholipid
in lung surfactant.
Dyspnoea
Shortness of breath or difficulty in breathing.
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Electron
Subatomic particle with a charge of negative electricity.
Endotracheal tube
A large bore catheter inserted through the mouth or nose into
the trachea, to maintain a patent airway, to ventilate patients
with respiratory insufficiency, prevent aspiration of material,
administer drugs, or for delivering oxygen.
Epithelium
A collection of cells which make up the lining of the vessels,
body cavities, glands and cavities in the body.
Exocytosis
The mechanism of binding of lamellar bodies to the type II
cell wall with subsequent deposition of materials into the
aqueous hypophase.
Exogenous
Growing or originating outside the body.
Expiratory grunt
Noise made on expiration.
Expiratory reserve volume (ERV)
The air expired in excess of tidal volume during maximal forced
expiration.
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Foetal lung fluid
Fills the lungs before birth. Appears in the human lung during
the second trimester of gestation (from 14th
to 26th weeks).
Fibrosis
Formation of scar tissue caused by inflammation or irritation.
Fi02
Fraction of inspired oxygen concentration.
Fluid overload
The fluid present in the body is increased and this results
in adverse effects such as odema and heart failure. It can
arise as a result of 2 main problems; firstly renal damage
so the kidneys can not excrete the correct amount of fluid
resulting in fluid build up. Or secondarily when a large volume
of fluid had to given to the baby to treat another condition
such as sepsis or NEC.
Frequency
Breaths per minute.
Functional residual
capacity (FRC)
Air remaining at end expiration that serves to keep the lungs
open.
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Golgi system
Small membranous structures found in most cells associated
with the formation of glycoproteins, mucopolysaccharides and
other substances.
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Heart murmur
An abnormal sound heard during auscultatory examination of
the heart, caused by altered blood flow into a chamber or
through a valve.
Hernia
Protrusion of an organ through an abnormal opening in the
muscle wall of the cavity that surrounds it.
Hydrophilic
The property of attracting water molecules.
Hydrophobic
The property of repelling water molecules.
Hypocarbia
Abnormally low level of carbon dioxide in the blood.
Hypoglycaemia
A less than normal amount of glucose in the blood.
Hypoplasia
Incomplete or underdeveloped organ or tissue.
Hypotension
Low blood pressure which is not adequate for normal perfusion
and oxygenation of the tissues.
Hypothermia
An abnormal and dangerous condition in which the body temperature
falls below a certain critical level.
Hypoxia
Inadequate oxygen at the cellular level.
Hypoxaemia
An abnormal deficiency of oxygen in the arterial blood.
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IE ratio
Ratio between inspiratory time and expiratory time. Normally
ratios of 1:1 to 1:3 are used.
Interstitial fluid
Extracellular fluid that fills the spaces between most of
the cells of the body and makes up a substantial portion of
the liquid environment of the body.
Intestinal ischaemia
A decreased supply of oxygenated blood to the intestines.
Intrapartum
The period of labour and delivery.
Intrapleural pressure
Pressure within the chest cavity.
Intratracheally
Administration via the trachea.
Intrauterine
Inside the womb.
Intraventricular
haemorrhage (IVH)
Bleeding within the ventricles of the brain.
Intrauterine growth
retardation (IUGR)
Failure of the fetus to grow. A condition due in part to foetal
malnutrition.
Inspiratory reserve
volume (IRV)
The air inspired in excess of tidal volume with maximal inspiratory
effort.
Ischaemia
A combination of hypoxia and poor perfusion resulting in metabolic
acidosis and possible organ damage.
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Lamellar bodies
Storage areas in cells.
Leakage
The action or result of leaking.
Lecithin
Any of a group of phospholipids which are essential for the
metabolism of fats. Dipalmitoyl phosphatidylcholine (DPPC)
is a lecithin.
Lipid
Organic compounds that are insoluble in water, including fatty
acids, oils, waxes and steroids.
Liquid ventilation
Use of a liquid oxygenated perflurocarbon (PFC) liquid for
delivery of dissolved oxygen and removal of CO2.
Lung aeration
Getting air into the lungs.
Lung compliance
The relationship between a given volume change and the pressure
difference required to produce that change in volume. In a
compliant lung, a small change in pressure leads to a large
change in volume. The opposite is true in noncompliant lungs.
Lymphatics
Vessels in the body which transport fats, proteins and other
substances.
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Macrophages
A phagocytic cell which defends against infection or disposes
of products from the breakdown of cells.
Meconium
Material that collects in the intestines of a foetus and forms
the first stools of a newborn.
Meconium aspiration
The inhalation of meconium by the foetus or newborn, which
can block the air passages, causing failure of the lungs to
expand or other pulmonary dysfunction.
Minute volume (MV)
This is the volume of air inspired in one minute.
Mucus
The viscous, slippery secretions of mucous membranes and glands.
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Necrotising enterocolitis (NEC)
An acute inflammatory bowel disorder.
Neutron
Subatomic particle with no charge.
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Oesophagus
The muscular canal extending from the pharynx to the stomach.
Organelles
Any one of various particles of living substance bound within
most cells, such as the mitochondria, the golgi system endoplastic
reticulum, the lysosomes and the centrioles.
Oxygen toxicity
Damage to cells that occurs following exposure to oxygen.
Oxygenated perflurocarbon (PFC)
Used in liquid ventilation for the delivery of dissolved oxygen
and removal of CO2.
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Patent (’open’)
ductus arteriosus
The persistence of the foetal ductus arteriosus (a blood vessel)
between the pulmonary artery and the aorta. Its failure to
close can lead to worsening of the respiratory condition and
heart failure..
Patent foramen ovale
(PFO)
Persitance of a communication between the right and left atrium
after birth.
Peak inspiratory
pressure (PIP)
The maximum pressure delivered by a ventilator during each
inspiratory cycle.
Peptide
A compound of two or more amino acids linked in sequence.
Periventricular
haemorrhage (PVH)
Bleeding into the brain tissue
Periventricular
leucomalacia (PVL)
Necrosis of the white matter in the brain resulting from ischemic
injury often due to a period of underperfusion of the brain
tissue which can follow many events while inutero or after
birth.
Persistent pulmonary
hypertension
A persistent condition of abnormally high pressure within
the pulmonary circulation.
Phagocyte
Any cells capable of ingesting microorganisms and other antigens
that are coated with antibody or complement.
Phospholipids
One of a class of compounds widely distributed in living cells,
and one of the main constituents of surfactant.
Phospholipid fraction
A purified sample containing only phospholipids without proteins
or other classes of molecules.
Phosphatidylcholine
The main phospholipid found in lung surfactant.
Phosphatidylglycerol
The second most common phospholipid found in lung surfactant.
Pneumonia
Acute microbial or viral infection and inflammation of the
lungs.
Pneumothorax
Air is trapped inside the chest between the chest wall and
the lung, causing the
lung to collapse.
Positive end-expiratory
pressure (PEEP)
The maximum pressure delivered to the lungs during expiration
cycle.
Pre-eclampsia
An abnormal condition of pregnancy characterised by the onset
of acute hypertension after the 24th week of gestation.
Prophylaxis
Prevention or protection against disease often using a biologic,
chemical or mechanical agent.
Prostaglandin
A group of fatty acids with varying hormone-like effects,
including the promotion of uterine contractions.
PROMS
The spontaneous rupture of the amniotic sac before labour.
Proteins
Nitrogenous compounds composed of one or more chains of amino
acids.
Proton
Subatomic particle with a positive electric charge.
Pulmonary haemorrhage
Acute loss of blood from the lungs or respiratory system.
Pulmonary interstitial
emphysema (PIE)
Air is trapped between the tiny air sacs, encircling the smallest
blood vessels and bronchi.
Pulmonary oedema
Accumulation of extravascular fluid in lung tissues and alveoli.
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Reflux
An abnormal backward or return flow of a liquid.
Rescue
Treatment given when the signs of a condition are seen.
Residual volume
(RV)
The air left in the lungs after a maximal expiratory effort.
Retinopathy
of prematurity (ROP)
Caused by rapid growth of blood vessels in the retina. Leakage
causes scarring, which as they shrink sometimes detach the
retina.
Retractions
Indrawing of the sternum and spaces between the ribs during
inspiration.
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Sepsis
Generalised infection or infection of the blood stream.
Suction port
An opening in a ventilator circuit, for suctioning of excess
secretions to prevent tube blocking, through which surfactant
can be administered.
SP-A
Surfactant protein which has a host defence function. Binds
DPPC, regulates turnover and secretion. Reduces inhibition
by serum proteins, forms tubular myelin and accelerates adsorption
promoted by SP-B.
SP-B
Surfactant protein which assists adsorption & spreading,
formation of tubular myelin and surfactant monolayer.
SP-C
Surfactant protein which assists adsorption & spreading.
SP-D
Surfactant protein which activates macrophages & binds
to lipopolysacharide.
Steroid
Organic compounds with a characteristic structure of four
rings of carbon atoms, including many hormones, alkaloids
and vitamins.
Sternal retraction
see retraction.
Structural pulmonary
immaturity
Immature, underdeveloped lungs or respiratory system.
Surfactant
An agent which reduces surface tension at the the air-liquid
interface in the alveoli allowing lung volumes to be established
and reducing the work of breathing. Surfactant is a mixture
of phospholipids, neutral lipids and proteins.
Surfactant lipids
They make up 90% of lung surfactant and are important in the
formation of the surfactant monolayer on the alveolar-air
interface.
Surfactant monolayer
The spreading of surfactant at the alveolar-air interface.
Systemic hypoxaemia
An abnormal deficiency of oxygen throughout the body.
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Tachypnoea
An abnormally rapid rate of breathing.
Tidal volume (TV)
The amount of air that moves into the lungs with each breath
during passive breathing.
Trachea
A nearly cylindrical tube in the neck, composed of cartilage
and membrane extending from the larynx to the point where
it divides into two bronchi.
Tubular myelin
A lattice-like structure which is probably the precursor of
the surfactant monolayer.
Type I and type
II cells
Types of alveolar cells which have roles in the formation
and re-cycling of surfactant.
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Ventricle
of the brain
Are cavities that are filled with cerebrospinal fluid.
Vital capacity
The greatest amount of air that can be expired after maximal
inspiratory effort.
Volutrauma
The damaging effect on lung tissue of delivering excess volume
of gas during ventilation
Volvulus
A twisting of the bowel on itself, causing intestinal obstruction.
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Work of breathing
The energy required to overcome the frictional resistance
forces that oppose volume expansion and gas flow into and
out of the lungs during respiration.
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