2003 Exam Flashcards
(261 cards)
1
Q
Why is clinical reasoning important?
A
Reviews the complex nature of patient healthcare in a way that is wholistic and person-centred.
Assists the nurse to respond to challenging and dynamic patient situations.
Assists in identifying the deteriorating patient.
2
Q
What is clinical reasoning
A
The process by which nurses (and other clinicians) collect cues, process the information come to an understanding of a patient problem or situation, plan and implement interventions, evaluate outcomes, and reflect on and learn from the process
3
Q
What are the 8 stages of clinical reasoning
A
Consider the patient situation Collect cues/information Process information Identify problems/issues Establish goals Take action Evaluation outcomes Reflect on process and new learning
4
Q
Homeostasis
A
Any self-regulating process by which biological systems tend to maintain stability while adjusting to conditions that are optimal for survival. Ifhomeostasisis successful,lifecontinues; if unsuccessful, disaster ordeathensues. The stability attained is actually adynamic equilibrium, in which continuous change occurs yet relatively uniform conditions prevail.
5
Q
Osmoregulation/excretion
A
Excess water, salt, and urea expelled by the body. Involves ADH, aldosterone, angiotensin II and carbon dioxide. Organs involved include kidney, urinary bladder, ureters, urethra (urinary system), pituitary gland (endocrine) and lungs (respiratory system)
6
Q
Thermoregulation
A
sweating, shivering, dilation/constriction of the blood vessels, insulation by adipose tissue to produce heat. Nerve impulses are involved. Involves skeletal muscles, nerves, blood vessels, skin and adipose tissue and hypothalamus
7
Q
Chemical regulation
A
Release of insulin and glucagon into the blood in response to rising and falling blood glucose levels. Involves the pancreas, liver, adrenal glands, lungs, brains and kidneys
8
Q
Disruption of Homeostasis
A
When the body’s cells don’t work properly, homeostatic balance is disrupted. This imbalance may lead to disease and cellular malfunction. This is caused by deficiency (cells not getting all they need) and toxicity (cells poisoned by things they don’t need). Inherited influences and external influences based on lifestyle choices and environmental exposure. The factors together influence body’s ability to maintain homeostatic balance.
9
Q
Homeostasis- Internal influences Heredity (genetics)
A
Medication can aid in the body regaining homeostasis. ie. Type 1 diabetes the pancreas does not produce adequate amounts of insulin to respond to changes in blood glucose level. Insulin replacement therapy aids the body in maintaining homeostasis by bringing glucose back to balance.
10
Q
Homeostasis External influences Lifestyle (nutrition). ie. menstruating woman not eating enough iron will become anaemic. Haemoglobin requires oxygen, therefore blood will have reduced oxygen carrying capacity. Can cause fatigue and extreme cases body tries to compensate by increasing cardiac output, leading to weakness, irregular heartbeat and heart failure
A
Lack of vitamins and nutrients will cause cells to not function properly, therefore greater risk of disease.
11
Q
Homeostasis External influences lifestyle (physical activity)
A
Physical activity essential for proper functioning of cells. Adequate rest and regular physical activity influence homeostasis. Poor physical activity can lead to disease
12
Q
Homeostasis- Mental Health
A
Physical and mental health are inseparable. Emotions cause chemical changes in body. Regular physical activity increases ability of cardiovascular system to deliver oxygen to body cells including brain cells. Medications may balance mood altering chemicals in the brain, that stabilise a disruption in homeostasis
13
Q
Homeostasis- Environmental exposure
A
Any substance interfering with cellular function and that causes cellular malfunction is a cellular toxin. Toxins= natural or synthetic drugs, plants, animal bites, air pollution. Drug overdose of a drug that affects the CNS, results in breathing and heart rate to be disrupted. This disruption to homeostatic balance can result in coma, brain damage or even death
14
Q
Osmosis/Diffusion Definition
A
Diffusion movement of molecules from high concentration to low concentration. Difference in concentrations is called a gradient. Bigger the difference in concentration the faster molecules will move to the lower concentration. Chemicals in the body are dissolved in water.
15
Q
Osmosis examples
A
Red Blood Cells are anucleate and are unable to control protein channels and carriers in their plasma membrane, therefore plasma membranes are permeable to water and certain solutes. Water moves in and out of RBC’s in response to changes in osmotic balance in the fluid they are suspended in.
Digestive system- Nutrient absorption, osmosis enables key nutrients to be absorbed into the intestines and individual cells after being broken down by chemical and mechanical processes. Active transport then distributes the nutrients to where they are required via the blood. Majority of osmosis occurs in the small intestine
16
Q
Dialysis and Osmosis
A
Process where only certain compounds (both solvent and solute molecules) are able to pass through selectively permeable dialysis membrane, however larger protein molecules cannot. Used to separate proteins from small ions and molecules and is used for purifications of proteins required for lab experiments.
17
Q
Hemodialysis
A
Used in the purification of blood in patients suffering renal malfunction. Blood circulated from cellophane dialysis tube suspended in dialysate. toxic end products of nitrogen metabolism such as urea from the blood pass through the dialysis membrane where they are removed and cells, proteins and other blood components are prevented due to their size. Blood is then returned to the body.
18
Q
Concentration gradient definition
A
Process of particles/solutes moving through a solution or gas from a higher number of particles to lower. These areas usually are separated by a membrane.
19
Q
Where do concentration gradients occur in the body
A
intestines- Digested food molecules (amino acid, glucose) move down a concentration gradient from intestine to blood. Waste products (carbon dioxide and urea) travel by diffusion from body cells into the bloodstream
lungs-Oxygen moves from high concentration (in the air sac) to a lower concentration (in the blood). Carbon dioxide moves from high concentration (in the blood) to a lower concentration (in the air sac).
20
Q
Inflammation definition
A
Complex biological response of body tissues to harmful stimuli such as pathogens or damaged cells or irritants. Is a protective response involving immune cells, blood vessels and molecular mediators. Function= eliminate the initial cause of cell injury, clear out necrotic cells and tissues damaged from the original insult and the inflammatory process and initiate tissue repair. The response is triggered by damage to living tissues. It is a defence mechanism that protects organisms from infection and injury. Purpose is to localise and eliminate the injurious agent and to remove damaged tissue components to enable the body to heal. Involves a change in blood flow, increase in blood vessel permeability, migration of fluid, proteins and white blood cells (leukocytes) from the circulation to the site of tissue damage.
21
Q
Patho of Inflammation signs and symptoms
A
5= heat, pain, redness, swelling, and loss of function
Physical effect of inflammatory response is blood circulation increasing around the infected area. Blood vessels dilate, permitting the increased blood flow to the area. Gaps appear in cell walls allowing larger blood cells (immune cells) to pass, therefore immune presence is strengthened.
Increase in body heat, which in itself has an antibiotic effect, swinging the balance of chemical reactions in favour of the host
22
Q
Main symptoms of the inflammatory response
A
The tissues in the area areredandwarm, as a result of the large amount of blood reaching the site.
The tissues in the area areswollen, due to the increased amount of blood and proteins that are present.
The area ispainful, due the expansion of tissues, causing mechanical pressure on nerve cells, and also due to the presence of pain mediators.
Once the inflammatory process has begun, it continues until the infection that caused it has been eradicated. Phagocytes continue to consume and destroy bacteria, the acquired immune system binds and disposes of harmful toxins.
Pusis produced, pus being thedebristhat is left over from the battle between the invader and the immune system. The colour of the pus depends on the organism causing the infection.
23
Q
What can go wrong with inflammation
A
Too little inflammation could lead to progressive tissue destruction by the harmful stimulus (e.g. bacteria) and compromise the survival of the organism.
Chronic inflammation may lead to a host of diseases, such ashay fever,rheumatoid arthritis, and even cancer (e.g.,gallbladder carcinoma).
Inflammation is therefore normally closely regulated by the body.
24
Q
Components of the respiratory system (top to bottom)
A
- Nasal passage
- Oral cavity
- Pharynx
- Larynx
- Trachea
- Lung
- Bronchi
- Bronchioles
- Diaphragm
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Pharynx
- Connecting tube between the nasal cavity and the larynx
- Works in the respiratory and digestive systems
- Allows inhaled air to pass into the trachea
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Larynx (voice box)
- Allows passage of air, while preventing food and drink from blocking the airway
- Air exhaled from the lungs travels through the larynx and vibrates the vocal cords
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Trachea (windpipe)
- Air filtration
| - Branches into the bronchi
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Bronchi
-Two tubes that carry air into the lungs
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Bronchioles
- Lined with cilia (tiny hairs that carry mucus up and out)
| - Lead directly into the lungs
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Lungs
- Right lung has three lobes; the left lung has two lobes
- Left lung is smaller to accommodate the heart
- Lead into the alveoli
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Alveoli
- Spongy sacs within the lungs
- Exchange of oxygen and carbon dioxide occur here
- 0.2 micrometers thick - contain the pulmonary capillaries
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Capillaries
- Blood passes through these
- Pulmonary artery – blood containing CO2 goes into air sacs
- Pulmonary vein – blood containing O2 goes to the heart
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Diaphragm
- Dome shaped muscle
- Controls breathing and separates the chest cavity from the abdominal cavity
- Inhalation – flattens out and pulls forward making more space for the lungs
- Exhalation – expands and forces air out
34
Function of the lymphatic system
Maintains fluid levels in our body tissue by removing fluids that leak out of our blood vessels
Optimal functioning of immune responses
Monitor lymph flowing into them and produce cells and antibodies which protect us from infection and disease
Absorbs fats from the intestine
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spleen
- Located in the abdomen – under the diaphragm
- Filters and monitors our blood
- Contains macrophages (garbage trucks)
- Also create and store white blood cells – immunity
- Destroys old/damaged red blood cells
- Assists in increasing blood volume quickly
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Thymus
- Inside the ribcage – behind the breastbone
- Filters and monitors blood content
- Produces T-lymphocytes which circulate around the body
- Cell mediated response to bacteria/infection
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Lymph Tissue
- Respiratory system is lined with lymphatic tissue
| - Monitor exposure to the external environment
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Lymph Nodes
- Filters in multiple spots around the body
- Associated with body defence
- Bacteria filter through the lymph nodes
- Lymphocytes attack and kill bacteria, viruses and cancer cells
39
What is Pharmacodynamics
- Pharmacodynamics is the branch of pharmacology concerned with the effects of drugs and the mechanism of their action.
- Pharmacodynamics is the mechanism where drugs exert their effects on the body "what the drug does to the body"
40
What is the aim of drug therapy
- The aim of drug therapy is to reverse any changes so the body can return to its homeostatic state.
- All bodily functions are a result of interactions of various chemicals and drugs act by interfering with these processes.
- Drugs usually combine with particular chemicals to modify its effect on the body.
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Effect of drugs acting by chemical reactions
- These drugs have a direct chemical action on the body.
| - Simple chemistry is all the drug is required to do to have a physiological effect in the patient.
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Effect of drugs acting on enzymes
- Enzymes are catalysts that can carry out numerous reaction in the body.
- A catalyst is involved in a reaction but remains unchanged at the end of the reaction.
- There are two types of enzyme inhibition – competitive and non-competitive
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Enzymes- Competitive inhibition
- The drug competes with the natural substrate for the active centre of the enzyme.
- The more drug that is present with the enzyme the slower the enzyme reaction.
- Competitive inhibition occurs when the enzyme combines with a substance that has a very similar structure to the normal substrate.
44
Enzymes- Non-competitive Inhibition
- The inhibitor binds to a site distinct and remote from the active centre of the enzyme.
- This leads to a change in the structure of the enzyme rendering it inactive.
- Inhibition occurs in a permanent and irreversible fashion.
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Effect of drugs acting on receptors
- A drug which binds to a receptor and produces a maximum effect is called a full agonist.
- A drug which binds and produces less than a maximal effect is called a partial agonist.
- Partial agonists produce and effect if no agonist is present but act as antagonishst in the presence of a full agonist.
- Drugs which bind but do not activate a secondary messenger system are called antagonists.
- Antagonists only produce effects by blocking access of the natural transmitter (agonist) to the receptor.
- Ion channel receptors associated with transporting ions (sodium, potassium, calcium) to and from cells.
46
What is Pharmacokinetics
Deals with the movement of the medication through the body or what the body does to the medication.
Pharmacokinetics can be further broken up into ADME:
Absorption
Distribution
Metabolism
Excretion
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Absorption- Pharmacokinetics
the process of medication uptake into the body fluids for distribution to its site of action.
Drug absorption is the movement of a drug into the bloodstream after administration.
A drug product is the actual dosage form of a drug—a tablet, capsule, suppository, transdermal patch, or solution.
Thus, a drug's effects, even at the same dose, may vary from one drug product to another.
48
Factors that affect absorption
The way a drug product is designed and manufactured
Its physical and chemical properties
Other ingredients it contains
The physiologic characteristics of the person taking the drug
How the drug is stored
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What is an active ingredient
the chemical substance (the drug) that is taken to produce the desired effect (such as lowering blood pressure; managing a respiratory episode).
50
What are the additives
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The additives (inactive ingredients such as diluents, stabilizers, disintegrants, and lubricants) are mixed with the drug to make it easier to swallow or help break it up in the gastrointestinal tract.
The type and amount of additives and the degree of compression affect how quickly the tablet disintegrates and how quickly the drug is absorbed.
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51
What is distribution
After a drug is absorbed into the bloodstream, it rapidly circulates through the body.
The average circulation time of blood is 1 minute. As the blood recirculates, the drug moves from the bloodstream into the body’s tissues.
Once absorbed, most drugs do not spread evenly throughout the body.
Drugs that dissolve in water (water-soluble drugs), tend to stay within the blood and the fluid that surrounds cells (interstitial space).
Drugs that dissolve in fat (fat-soluble drugs), tend to concentrate in fatty tissues.
Other drugs concentrate mainly in only one small part of the body because the tissues there have a special attraction for and ability to retain that drug.
Drugs penetrate different tissues at different speeds, depending on the drug’s ability to cross membranes.
A highly fat-soluble drug, rapidly enters the brain
A water-soluble drug, does not.
In general, fat-soluble drugs can cross cell membranes more quickly than water-soluble drugs can. For some drugs, transport mechanisms aid movement into or out of the tissues.
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Why do some drugs leave the bloodstream slowly
because they bind tightly to proteins circulating in the blood.
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Why do some drugs leave the bloodstream readily
Others quickly leave the bloodstream and enter other tissues because they are less tightly bound to blood proteins.
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Why do some drugs accumulate in tissues
Some drugs accumulate in certain tissues which can also act as reservoirs of extra drug.
These tissues slowly release the drug into the bloodstream, keeping blood levels of the drug from decreasing rapidly and thereby prolonging the effect of the drug.
Some drugs, such as those that accumulate in fatty tissues, leave the tissues so slowly that they circulate in the bloodstream for days after a person has stopped taking the drug.
55
How may the distribution of a drug change in the obese and elderly?
Obese people may store large amounts of fat-soluble drugs, whereas very thin people may store relatively little.
Older people, even when thin, may store large amounts of fat-soluble drugs because the proportion of body fat increases with age.
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Metabolism
Drugs are chemically altered by the body (metabolised)
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Prodrugs
Administered in an inactive form which are metabolised in to an active form. The resulting active metabolites produce the desired therapeutic effect
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Metabolites
Metabolites are the substances that result from metabolism, and may be inactive, similar to or different from the original drug in therapeutic activity or toxicity
Metabolites may be metabolized further instead of being excreted from the body.
59
What is the primary site for drug metabolism
The liver
Once in the liver, enzymes convert prodrugs to active metabolites or convert active drugs to inactive forms.
The liver’s primary mechanism for metabolizing drugs is via a specific group of cytochrome P-450 enzymes.
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What impact can drugs and food have on the cytochrome P-450 enzymes
If these substances decrease the ability of the enzymes to break down a drug, then that drug's effects (including side effects) are increased.
If the substances increase the ability of the enzymes to break down a drug, then that drug's effects are decreased.
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Affect of age on metabolism
Because metabolic enzyme systems are only partially developed at birth, newborns have difficulty metabolizing certain drugs.
As people age, enzymatic activity decreases, so that older people, like newborns, cannot metabolize drugs as well as younger adults and children do.
Consequently, newborns and older people often need smaller doses per pound of body weight than do young or middle-aged adults.
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Excretion
All drugs are eventually eliminated from the body.
They may be eliminated after being metabolised, or they may be eliminated intact.
Most drugs, particularly water-soluble drugs and their metabolites, are eliminated largely by the kidneys in urine.
Therefore, drug dosing depends largely on kidney function.
Some drugs are eliminated by excretion in the bile (a greenish yellow fluid secreted by the liver and stored in the gallbladder).
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Excretion in urine
To be extensively excreted in urine the drug or metabolite must be water soluble and not bound to proteins too tightly in the bloodstream.
The acidity of urine that is influenced by diet, drugs and kidney disorders can affect the rate at which the kidneys excrete drugs
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Urine and the treatment of poisoning
the acidity of the urine is changed by giving antacids (such as sodium bicarbonate) or acidic substances (such as ammonium chloride) orally to speed up the excretion of the drug.
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What affects the kidneys ability to excrete drugs
Urine flow
Blood flow through the kidneys
The condition of the kidneys
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How can kidney function become impaired?
```
Many disorders (especially high blood pressure, diabetes, and recurring kidney infections), exposure to high levels of toxic chemicals, and by age-related changes.
As people age, kidney function slowly declines.
The kidneys of an 85-year-old person excrete drugs only about half as efficiently as those of a 35-year-old person.
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Excretion and bile
Some drugs pass through the liver unchanged and are excreted in bile
Other drugs are converted to metabolites in the liver before they are excreted in bile
The bile then enters the digestive tract, where the drugs are either excreted in faeces or reabsorbed into the bloodstream and recycled
If there is liver malfunction, the dosage of a drug that is eliminated primarily by metabolism in the liver may need to be adjusted
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Other forms of drug elimination
Some are excreted in sweat, saliva, breast milk, and even exhaled air, commonly in small amounts
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Inhaled anaesthetics elimination
Through excretion in exhaled air
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What is pharmacology?
the branch of biology concerned with the study of drug action
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Definition of a drug
any man-made, natural, or endogenous molecule which exerts a biochemical or physiological effect on the cell, tissue, organ, or organism.
any substance or product that is used to modify or explore physiological system or pathological states for the benefit of the recipient.
Drugs usually affect living tissues
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Medication definition
a drug mixed in a formulation with other ingredients to improve the stability, taste or physical form , in order to allow appropriate administration of the active drug.
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Morphine
Opium poppy alkaloid (papaver somniferum)
| It is a species of plant from which opium and poppy seeds are derived
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Generic name
Approved name
| Groups of medications that have similar actions often have similar sounding generic names ie. paracetamol
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Brand names
Chosen by the company who produces it, memorable for advertising and easy to pronounce ie. panadol
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Mechanism of Action definition
How the medication works
the specific biochemical interaction through which a drug produces its pharmacological effect.
A mechanism of action usually includes mention of the specific molecular targets to which the drug binds, such as an enzyme or receptor.
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Adverse effect definition
Any unexpected or dangerous reaction to a drug.
| The onset of the adverse reaction may be sudden or develop over time.
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Binding
The degree medications attach to proteins within the blood.
A drug's efficiency may be affected by the degree to which it binds.
The less bound a drug is, the more efficiently it can traverse cell membranes or diffuse.
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Lipophilic
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Lipophilicity refers to the ability of a chemical compound to dissolve in fats, oils, lipids, and non-polar solvents such as hexane or toluene.
Examples include:
Prednisolone
Fentanyl
Nitrous oxide (general anaesthetic)
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80
Hydrophilic
The ability of a chemical compound to be absorbed through water
Hydrophilic compounds are not absorbed well in the body
Examples include
Gentamycin
Ibuprofen
Metoclopramide
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The first pass effect
The rapid uptake and metabolism of an agent into inactive compounds by the liver, immediately after enteric absorption and before it reaches the systemic circulation.
Mainly occurs in the gut and liver
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Half life
how long it takes for half of the dose to be eliminated from the bloodstream.
The time it takes for the plasma concentration of a drug to reach half of its original concentration
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Bioavaliability
The degree and rate at which an administered drug is absorbed by the body's circulatory system, the systemic circulation.
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Salbutamol (respiratory drugs)
- A short-acting, selective beta2-adrenergic receptor agonist used in the treatment of asthma and COPD.
- Used for acute episodes of bronchospasm caused by asthma, chronic bronchitis, and Chronic Obstructive Pulmonary Disease
- Also used prophylactically for exercise induced asthma
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Ipratropium
This medication is an anticholinergic (parasympatholytic) agent
Used for various bronchial disorders, in rhinitis, and as an antiarrhythmic.
Used to control and prevent symptoms (wheezing and shortness of breath) caused by ongoing lung disease (COPD which includes bronchitis and emphysema).
It works by relaxing the muscles around the airways so that they open up and you can breathe more easily.
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Prednisolone
Works by reducing the number of inflammatory cells in the airways, including eosinophils, T lymphocytes, mast cells, and dendritic cells.
It has a broad spectrum of anti-inflammatory effects in asthma
used to treat conditions such as arthritis, blood problems, immune system disorders, skin and eye conditions, breathing problems, cancer, and severe allergies.
It decreases your immune system's response to various diseases to reduce symptoms such as pain, swelling and allergic-type reactions.
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Oxygen
Dioxygen is used in cellular respiration and many major classes of organic molecules in living organisms contain oxygen.
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What makes up the skeletal system
206 bones, tendons, ligaments and cartilage
| Axial and Appendicular skeleton
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Functions of the skeletal system
support, movement, protection, blood cell production, calcium storage and endocrine regulatio
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Axial Skeleton function
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Transmits weight from the head, trunk and upper extremities down to the hip joints
80 bones
Vertebral column
Rib cage
Skull
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Appendicular skeleton function
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Walking, running and other movement
Protection of major organs responsible for digestion, excretion and reproduction
126 bones
Pectoral girdles
Upper limbs
Pelvic girdle
Lower limbs
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Muscular system make up and function
Responsible for movement
700 known muscles that equate to half of body weight
Each muscle is constructed of skeletal muscle tissue, blood vessels and nerves
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3 types of muscle
Visceral muscle
Cardiac muscle
Skeletal muscle
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Visceral muscle
Stomach, intestines and blood vessels
Weakest of all muscle tissue
Contract to move substances through the organs
Involuntary muscle – smooth muscle
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Cardiac Muscle
Found only in the heart
Pumping blood through the body
Natural pacemaker stimulates other muscles to contract
Assist with the spread of electrochemical signals
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Skeletal muscle
Only voluntary muscle tissue in the human body
Contracts to move parts of the body closer to the bone that the muscle is attached to.
Attached to 2 bones across a joint
Bunch together to form long, straight, multinucleated fibres
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Causes of Compartment syndrome (orthopaedic trauma)
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Secondary to orthopaedic trauma – fracture
Secondary to constricting bandages/casts
Painful and dangerous condition
Related to pressure build-up from internal bleeding
Related to swelling of tissues
Gunshot injury
Crush injury
Burns
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Pathophysiology of compartment syndrome
Pressure decreases blood flow, depriving muscles and nerves of nourishment
Disrupted blood flow to muscle and nerves leads to the death of these cells (ischaemia)
Trauma
Rise in Intracompartmental Pressure
Venous Obstruction and Muscle/Nerve Ischaemia
Further rise in Compartmental Pressure
Capillary Obstruction and Myocyte Necrosis
Arterial Obstruction
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Symptoms of compartment syndrome
Severe pain
Sensation of pins and needles
Weakness of the affected area
In the most severe cases myoglobinuria (myoglobin in the urine) can occur.
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Compartment syndrome definition
a potentially life-threatening condition resulting from increased pressure within a confined body space, usually a leg or forearm.
Without treatment can lead to loss of limb or even death unless early diagnosis is made and treatment implemented.
Two classifications (acute and chronic)
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6 P's of compartment syndrome
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Paraesthesia
Pain
Paresis
Pallor
Poikilothermia
pulselessness
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Paraesthesia (compartment syndrome)
Altered/loss of sensation
| The patient may experience a pins-and-needles sensation, tingling, tickling, prickling or burning
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Pain (compartment syndrome)
While this is expected with a musculoskeletal injury, pain described as deep and constant and poorly localized, that increases when stretching or manipulating the muscle, and is unrelieved by pain medications is not normal and could be a sign of compartment syndrome
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Paresis (compartment syndrome)
Though this is usually a late finding, paralysis or numbness in a limb can be a sign of compartment syndrome. This is most common when a patient’s leg or arm has been crushed in an accident.
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Pallor (compartment syndrome)
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Pale extremities (toes/fingers)
If you notice that your patient has pale, shiny skin, especially distal to the injury site, this is an important symptom that must be reported immediately
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Poikilothermia (compartment syndrome)
refers to a body part that regulates its temperature with surrounding areas, is an important one. If you notice a limb that feels cooler than surrounding areas, the patient may have compartment syndrome.
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Pulselessness
A diminished or absent pulse in an affected area can be caused by compartment syndrome, which creates a tourniquet-like effect and cuts off circulation to the limb
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Open reduction internal fixation
Operation in orthopedics that involves the surgical implementation of implants for the purpose of repairing a bone
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Common injuries that affect breathing
Pneumothorax (Simple, Tension or open)
Haemothorax
Rib Fractures (simple or flail chest)
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What can a pneumothorax be classifies as
Simple, tension or open
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How common is pneumothorax
Present in up to 20% of chest injuries
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Tension pneumothorax
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Blunt or penetrating injury
Breath sounds decreased or absent
Marked ventilatory distress
Haemodynamic compromise
A simple pneumothorax may progress to a tension pneumothorax as air continues to accumulate within the affected hemithorax
Tension pneumothorax is life-threatening
Needle decompression may be required
May be associated with a hemothorax
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Simple pneumothorax
Blunt or penetrating injury
Breath sounds decreased or absent
Mild to moderate ventilatory distress
May progress to tension
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Open pneumothorax
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Penetrating mechanism
May be “sucking” or “bubbling” chest wound
Respiratory distress
Mild to severe
May be associated with a hemothorax
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Symptoms of tension pneumothorax
Chest pain, shortness of breath, rapid heart rate, shallow breathing, anxiety, blue or ashen skin
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Treatment of pneumothorax
Immediate decompression is required through medical treatment:
Large bore needle
2nd intercostal space
Midclavicular line
Long term treatment is through the insertion of a chest tube
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The brain overview
Central organ that serves as the centre of the nervous system
Made up of 100 billion nerve cells that communicate through synapses
Surrounded by a layer of tissue - meninges
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What are the specialised areas of the brain
Cortex
Brain stem
Basal ganglia
Cerebellum
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What are the 4 lobes of the brain
Frontal lobe
Parietal lobe
Temporal lobe
Occipital lobe
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What does the circulatory system consist of
the heart, blood vessels and approximately 5L of blood.
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Function of circulatory system
Transports oxygen, nutrients, hormones and cellular waste products
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Structure of the heart
Epicardium, myocardium, endocardium
| Chambers- Right atrium, left atrium, right ventricle, left ventricle
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Blood vessels
Body’s highways – blood flows quickly and efficiently from the heart to the rest of the body
Size is variable dependant on the amount of blood that passes through
Contain a hollow area – the lumen (allows blood to flow)
Around the lumen is the wall – capillaries (thin) or arteries (thick)
Lined with simple squamous epithelium – keeps blood inside of the vessels and prevents clot formation
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3 types of blood vessels
Arteries
Capillaries
Veins
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Arteries
Carry blood away from the heart – impacts on blood pressure
Oxygenated, passing through the lungs
Thicker walls
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Capillaries
Smallest and thinnest
Carry blood close to cells (gas exchange, nutrients, waste products)
Sphincters regulate blood flow
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Veins
Medium thickness
| Return blood to the heart – lower blood pressure
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What is antimicrobial therapy?
Antimicrobials destroy microbes (microorganisms)
It involves the treatment of an infectious disease to help cure or control most types of infections
Classification (inhibit cell wall synthesis; alter nucleic acid metabolism; inhibit protein synthesis)
Selection (confirm the presence of an infection; identification of pathogen; monitor therapeutic response)
Pharmacokinetics and pharmacodynamics are crucial (bacteriostatic or bactericidal)
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Groups of antimicrobials
Biocides, antiseptics, anti-infectives
Antibacterials, antivirals, antifungals
Antibiotics
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Colonisation
microbe establishing itself on the bodies surface
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Subclinical infection
None or mild symptoms, asymptomatic
| Carriers may harbor and spread infectious agent for long periods of time in absence of signs or symptoms
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Infectious disease
significant signs and symptoms evident in the host
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Primary infection
Initial infection – can lead to secondary infections
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Primary pathogen
microbe or virus that causes disease in otherwise healthy individual
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Opportunistic pathogen
causes disease only when body’s innate or adaptive defences are compromised or when introduced into unusual location
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Virulence and virulence factors
Virulence refers to degree of pathogenicity
| Virulence factors are traits that allow microorganism to cause disease
137
Incubation period- time between infection and onset
Varies considerably: few days for common cold to even years for Hansen’s disease (leprosy)
Depends on growth rate, host’s condition, infectious dose
138
Convalescence
recuperation, recovery from disease
139
Antibiotic resistance
with the increasing use of antimicrobial treatment to fight infections, there are some organisms that have become resistant to antibiotic therapy
The most common known are MRSA (Methycillin-resistance Staphylococcus aureus) and multidrug-resistant Streptococcus pneumonia
140
Intrinsic resistance
refers to the organism’s ‘innate chromosomal (genetic) makeup’ that specifies resistance
141
Acquired resistance
Arises in an organism because of a change (mutation) in in its genetic makeup or because of the acquisition of new genetic information (new DNA)
142
What characterises wound and skin infections
Wound and skin infections are the growth and spread of microbes, usually bacteria, within the skin or a break or wound in the skin.
These infections trigger the body's immune system and cause inflammation and tissue damage within the skin or wound and slow the healing process.
143
Spread of infection
Some infections spread to other organs and/or into the blood (septicemia) and cause a body-wide (systemic) infection.
Many infections remain confined to a small area, such as an infected scratch or hair follicle, and usually resolve on their own.
144
How is the skin the body's first line of defence
If there is a break in the skin or if the immune system is weakened, then the microbes may cause a wound or skin infection.
145
Layers and makeup of the skin
the outer epidermis, the dermis – where many hair follicles and sweat glands are located – and the fatty subcutaneous layer.
Below these layers are membranes that protect connective tissues, muscle, and bone.
Wounds can penetrate any of these layers, and skin infections can spread into them.
146
Wound healing
a complex process that involves many related systems, chemicals, and cells working together to clean the wound, seal its edges, and to produce new tissues and blood vessels.
147
What are wounds
Wounds are breaks in the integrity of the skin and tissues.
They may be superficial cuts, scrapes or scratches but also include deeper cuts, punctures, burns, or may be the result of surgical or dental procedures.
148
Conditions that increase risk of wound infections
people with underlying conditions are at risk of slower wound healing and greater risk of wound infections.
Poor blood circulation
Diabetes
Weakened/suppressed immune system (e.g., HIV/AIDS, organ transplant recipient)
Low mobility or immobility (e.g., confined to bed, paralysis)
Malnutrition
149
When may infections become chronic
When infections penetrate deep into the body into tissues such as bone, or when they occur in tissue that has inadequate circulation, they can become difficult to treat and may become chronic infections.
Skin and wound infections interfere with the healing process and can create additional tissue damage.
150
Rights of medication administration
```
Right patient
right medication
right dose
right route
right time
right documentation
right reason
right response
right client education
right to refuse
right assessment
right evaluation
```
151
Medication errors
Errors can occur with prescribing, documenting, transcribing, dispensing, administering and monitoring.
Nurse has to double check themselves and others involved that they have done job correctly
152
Adverse event (side effect)
injury resulting from medication intervention related to a drug
153
Adverse drug reaction
any response to a drug, which is noxious, unintended, and which occurs at doses normally (and appropriately) used for the prophylaxis, diagnosis, or therapy of disease
Vary from life threatening anaphylaxis to minor side effects
154
Risk factors for adverse drug reactions
```
Age – The elderly and neonates
Gender – Women more susceptible than men
Multi-morbidities
Genetic factors
Renal insufficiency
Polypharmacy
Duration and frequency
Dose
Class of drug
```
155
What is a drug interaction
A drug interaction occurs when a patient’s response to a drug is modified by food, nutritional supplements, formulation excipients, environmental factors, other drugs or disease.
156
Harmful drug-drug interactions
Harmful drug–drug interactions are important as they cause 10–20% of the adverse drug reactions requiring hospitalisation and they can be avoided.
Elderly patients are especially vulnerable – with a strong relationship between increasing age, the number of drugs prescribed and the frequency of potential drug–drug interactions.
157
Behavioural drug-drug interactions
occur when one drug alters the patient’s behaviour to modify compliance with another drug. For example, a depressed patient taking an antidepressant may become more compliant with medication as symptoms improve.
158
Pharmaceutic drug-drug interactions
occur when the formulation of one drug is altered by another before it is administered. For example, precipitation of sodium thiopentone and vecuronium within an intravenous giving set.
159
Pharmacokinetic drug-drug interactions
occur when one drug changes the systemic concentration of another drug, altering ‘how much’ and for ‘how long’ it is present at the site of action.
160
Pharmacodynamic drug-drug interactions
occur when interacting drugs have either additive effects, in which case the overall effect is increased, or opposing effects, in which case the overall effect is decreased or even ‘cancelled out’
161
Altered bioavailability
This occurs when the amount of the object drug reaching the systemic circulation is affected by a perpetrator drug.
For orally administered drugs this occurs when absorption or first-pass metabolism is altered.
Drugs with low oral bioavailability are often affected while those with high bioavailability are seldom affected
162
Altered clearance
This occurs when the metabolism or excretion of the object drug is affected by a perpetrator drug.
Object drugs with a narrow therapeutic index are particularly vulnerable, as modest changes in concentration may be clinically important.
Perpetrator drugs known to strongly affect drug metabolism are more likely to cause large concentration changes and hence clinical consequences.
163
Drug-drug interactions and metabolism
Changes in drug metabolism are the most important causes of unexpected drug interactions.
These occur by changing drug clearance or oral bioavailability.
164
drug-drug interactions excretion
Some drugs are excreted from the body unchanged in the active form, usually in the urine or via the biliary tract in the faeces.
Changes in renal drug clearance may occur due to effects on renal tubular function or urine pH.
For example, probenecid reduces the renal clearance of anionic drugs such as methotrexate and penicillin.
165
Routes of administration
```
Topical (skin, rectal, otic, optic and nasal)
Oral
Sublingual
Parenteral
Intravenous
Intramuscular
Intradermal
Subcutaneous
```
166
How is pain defined
An unpleasant sensory and emotional experience associated with actual or potential tissue damage.
Not just a physical sensation, influenced by attitudes, beliefs, personality and social factors and can effect emotional and mental wellbeing.
167
3 main classifications of pain
Acute, chronic and cancer
168
Acute pain
lasts for a short time and occurs quickly, without warning following surgery or trauma or other condition.
169
Chronic Pain
lasts beyond the time expected for healing following surgery, trauma or other condition. It can also exist without a clear reason at all. Although chronic pain can be a symptom of disease, it can also be a disease in its own right, characterized with changes within the central nervous system (CNS).
170
Factors associated with chronic pain
Economic cost- Third most costly health condition
Access Issues- Less than 10% of people with chronic non-cancer pain gain access to effective care
Social Issues- sufferers can feel misunderstood and stigmatised, by co-workers, friends, family and even the medical profession. Decreased enjoyment of normal activities, loss of function, role change and relationship difficulties
Mental Health-One in five Australian adults with severe or very severe pain also suffer depression or other mood disorders.
171
Analgesic Drugs
a class of drugs that are designed to relieve pain without causing loss of consciousness.
172
Types of Analgesics
Opioid (narcotic) analgesics
Non-steroidal anti-inflammatory drugs (NSAID’s)
Central acting non-narcotic pain relievers such as Tylenol (acetaminophen) with no anti-inflammatory effect
Opioid and NSAIDs are the most commonly used analgesic medications.
173
Opioid Analgesics
Opioid medications are those that are chemically related to and interact with opioid receptors on nerve cells in the body and brain.
Safe to take for short period of time
Regular use can lead to dependence, addiction, overdose and death
174
Opioid overdoses
can be reversed with a medication known as naloxone – if given right away.
175
Adverse effects of opioids
respiratory depression, excessive sedation, constipation, nausea and dependence.
176
Opioid mechanism of action (opioid receptors)
Opioids produce effects on neurons by acting on receptors located on neuronal cell membranes. Three major types of opioid receptor, m, d and k (mu, delta and kappa
177
Opioid mechanism of action (sites of action)
Opioids have actions at two sites, the presynaptic nerve terminal and the postsynaptic neuron. The postsynaptic actions of opioids are inhibitory.
178
Presynaptic action of opioids
The presynaptic action of opioids is to inhibit neurotransmitter release, and this is their major effect in the nervous system. Presynaptic inhibition of neurotransmitter release may result in excitatory effects in a target neuron if the neurotransmitter normally produces an inhibitory effect.
If the opioid also has a postsynaptic inhibitory effect on the target neuron, the excitatory effects may not occur.
179
Opioid effect on CNS
Analgesia
Suppression of the cough reflex
Suppression of the respiratory center in the medulla
Sedation and many others
180
Opioid effect on PNS
Significant analgesic and anti-inflammatory effects
Decreased motility and increased tone in smooth muscle in the gut
Suppression of spinal reflexes and many others
181
Non-Steroidal Analgesics (NSAIDs) pharmacological actions and uses
Have significant anti-inflammatory properties with a reduction in inflammation leading to analgesia
Are effective for mild-to-moderate pain
When combined with opioid analgesics, can lead to a reduction in the opioid dose
Paracetamol is the most commonly used NSAID
Work through prostaglandin inhibition
182
NSAIDs adverse reactions
Common effects include gastrointestinal symptoms such as vomiting
Can lead to renal damage
183
Compound analgesics
drugs, which are combined with other drugs or substances to produce the pharmacological action of two or more drugs at once.
For example: Panadeine Forte
184
Polypharmacy
Concurrent use of multiple medications by a patient
NSAIDs are at a higher risk of polypharmacy as these medications are contained in multiple commercial products
Patients taking more than one of these products at the same time can lead to toxicity.
185
Ischemia
inadequate blood flow
186
Stroke
Occurs when ischemia to part of the brain results in death of brain cells
Movement, sensation, or emotions controlled by affected area are lost or impaired
Loss of function varies with location and extent of damage
187
Non-modifiable risk factors for stroke
Age
Gender (women more likely to have a fatal CVA)
Race (African Americans)
Heredity
188
Modifiable risk factors for stroke
```
Asymptomatic carotid stenosis
Diabetes mellitus
Heart disease, atrial fibrillation
Heave alcohol consumption, smoking
Hypercoagulability
Hyperlipidemia
Hypertension
Obesity
Oral contraceptive use
Physical inactivity
Sickle cell disease
```
189
What occurs if blood flow to the brain is interrupted
Brain requires continuous supply of O2 and glucose for neurons to function. If interrupted-
Neurologic metabolism is altered in 30 seconds
Metabolism stops in 2 minutes
Cell death occurs in 5 minutes
190
Atherosclerosis
a major cause of stroke
| Can lead to thrombus formation and contribute to emboli
191
Reversing ischemia
Potential reversal may occur ifblood flow can be restored early (<3 hours) and the ischemic cascade can be interrupted
Therefore less brain damage and less neurologic function lost
192
Transient Ischemic Attacks
Temporary focal loss of neurologic function caused by ischemia (analogous to angina in CAD)
Most resolve within 3 hours
May be due to micro-emboli that temporarily block blood flow
A warning sign of progressive cerebrovascular disease
193
Types of stroke
Ischemic (thrombotic, embolic)
| Hemorrhagic
194
Thrombotic stroke
Cerebral thrombosis is a narrowing of the artery by fatty deposits called plaque. Plaque can cause a clot to form, which blocks the passage of blood through the artery
Most common form of stroke
195
Embolic stroke
An embolus is a blood clot or other debris circulating the blood. When it reaches an artery in the brain that is too narrow pass through, it lodges there and blocks the flow of blood.
Second most common cause of stroke
Majority of emboli originate in heart, with plaque breaking off from the endocardium and entering circulation
Associated with sudden, rapid occurrence of severe clinical symptoms
196
hemorrhagic stroke
A burst blood vessel may allow blood to seep into and damage brain tissues or into subarachnoid space or ventricles until clotting shuts off the leak
Account for 15% of all strokes
197
Clinical manifestations of stroke
```
Motor activity
Elimination
Intellectual function
Spatial-perceptual alterations
Personality
Affect
Sensation
Communication
```
198
Ischemic stroke
Result of inadequate blood flow to brain due to partial or complete occlusion of an artery
Constitute 85% of all strokes
Most patients with ischemic stroke do not have a decreased level of consciousness in the first 24 hours
Symptoms often worsen during first 72 hours d/t cerebral edema
199
Intracerebral haemorrhage
Bleeding within the brain caused by a rupture of a vessel
Hypertension is the most important cause
Commonly occurs during activity
Often a sudden onset of symptoms that progress over minutes to hours b/c of ongoing bleeding
Manifestations include neurologic deficits, headache, decreased levels of consciousness, and HTN
200
Subarachnoid haemorrhage
Bleeding into cerebrospinal space between the arachnoid and pia mater
Commonly caused by rupture of a cerebral aneurysm
201
Motor function and stroke
```
Most obvious effect of stroke
Can include impairment of
Mobility
Respiratory function
Swallowing and speech
Gag reflex
Self-care abilities
Characteristic motor deficits (contra-lateral)
Loss of skilled voluntary movement
Impairment of integration of movements
Alterations in muscle tone (flaccid → spastic)
Alterations in reflexes (hypo → hyper)
```
202
Stroke and communication
Patient may experience aphasia when stroke damages the dominant hemisphere of the brain
Aphasia: total loss of comprehension and use of language
Dysphasia: difficulty with comprehension and use of language. Classified as nonfluent or fluent
Dysarthria: Disturbance in the muscular control of speech
Impairments in pronunciation, articulation, and phonation; NOT meaning or comprehension
203
Affect and stroke
May have difficulty controlling their emotions
Emotional responses may be exaggerated or unpredictable
Depression , impaired body image and loss of function can make this worse
May be frustrated by mobility and communication problems
204
Intellectual function and stroke
Memory and judgment may be impaired
| Left-brain stroke: more likely to result in memory problems related to language
205
Right brain damage (stroke on R side of the brain)
```
Paralysed left side- hemiplegia
Left sided neglect
Spatial-perceptual deficits
Tends to deny or minimize problems
Rapid performance, short attention span
Impulsive, safety problems
Impaired judgements
Impaired time concepts
```
206
Left brain damage (stroke on L side of the brain)
```
Paralysed right side- hemiplegia
impaired speech/language aphasias
Impaired right/left discrimination
Slow performance, cautious
Aware of deficits: depression, anxiety
Impaired comprehension related to language and math
```
207
Stroke and spatial perceptual alterations
Stroke on the right side of the brain is more likely to cause problems in spatial-perceptual orientation
However, this may occur with left-brain stroke
Spatial-perceptual problems may be divided into four categories
Incorrect perception of self and illness (may deny illness or body parts)
Erroneous perception of self in space (e.g., neglect all input from affected side; distance judgement)
Inability to recognize an object by sight, touch, or hearing
Inability to carry out learned sequential movements on command
208
Stroke and elimination
Most problems with elimination occur initially and are temporary
Prognosis for normal bladder function is excellent when only one hemisphere of brain is affected.
209
Why are diagnostic studies performed with stroke
done to
Confirm that it is a stroke
Identify the likely cause of the stroke
CT is the primary diagnostic test used after a stroke
210
Prevention of stroke
Education and management of modifiable risk factors to prevent a stroke
Close management of patients with known risk factors
Antiplatelet drugs (usually Aspirin) to prevent stroke in those with history of TIA
211
Surgical interventions for those with TIAs from carotid disease
Carotid endarterectomy
Transluminal angioplasty
Stenting
Extracranial-intracranial bypass
212
Stroke acute care interventions
```
Ensure patient airway
Remove dentures
Perform pulse oximetry
Maintain adequate oxygenation
IV access
Maintain BP according to guidelines
(treat if SBP > 220 or MAP > 130)Immediate CT scan to determine cause (ischemic vs hemorrhagic)
Measures to control ICP
Head & neck in alignment (avoid flexion)
Elevate HOB 30 ° if no symptoms of shock or injury
Avoid hip, knee flexion
Pain management and diuretics if needed
```
213
Treatment for strokes
Antiplatelets
Anticoagulants (Heparin, coumadin)
Must maintain therapeutic levels (PTT, INR)
Surgical interventions:
Immediate evacuation of hematomas that result from hemorrhagic stroke
Clip, wrap or coli aneurysm to prevent rebleed
214
Nurses must assess for the following in stroke patients
Clinical manifestations
Risk factors
Complications
215
Nursing diagnoses associated with a stroke
```
Ineffective tissue perfusion (cerebral)
Ineffective airway clearance
Impaired physical mobility
Impaired verbal communication
Unilateral neglect
Impaired urinary elimination
Impaired swallowing
Situational low self-esteem
```
216
Goals associated with a stroke
Maintain a stable or improved level of consciousness
Attain maximum physical functioning
Attain maximum self-care abilities and skills
Maximize communication abilities
Maintain adequate nutrition
Avoid complications of stroke
Maintain effective personal and family coping
217
Nursing implementations for effects of stroke on respiratory system
Management of the respiratory system is a nursing priority
Risk for aspiration pneumonia (why?)
Risks for airway obstruction
May require intubation and ventilation
218
nursing implementations for effects of stroke on cardiovascular system
Monitor closely
| Risk for DVT
219
nursing implementations for effects of stroke on musculoskeletal system
Prevent joint contractures and muscular atrophy
In the acute phase, range-of-motion exercises and positioning
Trochanter roll at hip to prevent external rotation
Hand cones to prevent hand contractures
Arm supports with slings and lap boards to prevent shoulder displacement
Avoid pulling patient by arm to avoid shoulder displacement
Posterior leg splints, footboards or high-topped shoes to prevent foot drop
Hand splints to reduce spasticity
220
Nursing implementations for effects of stroke on gastrointestinal system
May require nutrition support
Assess gag and swallowing before first feeding
Scrupulous oral hygiene after meals (food collects)
Place food on unaffected side
Foods with texture are more easily swallowed
Constipation is common
Manage with:
Physical activity
Adequate fluid intake
Laxatives, suppositories, stool softeners
221
Homonymous hemianopsia
Blindness in the same half of each visual field is a common
Initially approach from, and place needed objects on “good” side. Later, teach to scan and pay attention to affected side
222
Blood supply to the brain (right and left carotid arteries)
Have two divisions
External supply face and scalp with blood
Internal carotid arteries supply blood to most of the anterior portion of the cerebrum
223
Blood supply to the brain (right and left vertebral arteries)
Vertebrobasilar arteries supply the posterior of the cerebrum, part of the cerebellum and brain stem.
Decrease blood flow impairs the function of the frontal lobes
224
Circle of Willis
Circle of communicating arteries.
Other arteries arise and travel to all parts of the brain
Anterior cerebral artery
Middle cerebral artery
Posterior cerebral artery
Due to the circular formation if one main artery is occluded, smaller arteries can receive blood from other surrounding arteries.
225
Anterior cerebral artery
Extends upwards from the internal carotid artery
Supplies the frontal lobes
Stroke can result in opposite leg weakness
If both territories are affected, mental symptoms may result (akinetic mutism)
226
Middle cerebral artery
Largest branch of the internal carotid
Supplies a portion of the frontal lobes and lateral surface of the temporal and parietal lobes
Often the most occluded in a stroke
227
Posterior cerebral artery
Stem from the basilar artery
Supplies the temporal and occipital lobes
Infarction secondary to embolism
228
Types of neutrons
sensory neuron (unipolar), motor neuron (multipolar), pyramidal neuron, astrocyte, betz cell, microglia
229
Ischaemic cascade in stroke steps part 1
Lack of oxygen causes the neuron's normal process for making ATP for energy to fail.
The cell switches to anaerobic metabolism, producing lactic acid.
ATP-reliant ion transport pumps fail, causing the cell to become depolarized, allowing calcium (Ca2+), to flow into the cell.
The ion pumps can no longer transport calcium out of the cell, and intracellular calcium levels get too high.
The presence of calcium triggers the release of the excitatory amino acid neurotransmitter glutamate.
Glutamate stimulates AMPA receptors and Ca2+-permeable NMDA receptors, which open to allow more calcium into cells.
Excess calcium entry overexcites cells and causes the generation of harmful chemicals like free radicals, reactive oxygen species and calcium-dependent enzymes in a process called excitotoxicity.
Calcium can also cause the release of more glutamate.
230
Ischaemic cascade in stroke steps part 2
As the cell's membrane is broken down, it becomes more permeable, and more ions and harmful chemicals flow into the cell.
Mitochondria break down, releasing toxins and apopototic factors into the cell.
The apoptosis cascade is initiated, causing cells to "commit suicide."
If the cell dies through necrosis, it releases glutamate and toxic chemicals into the environment around it. Toxins poison nearby neurons, and glutamate can overexcite them.
If and when the brain is reperfused, a number of factors lead to reperfusion injury.
An inflammatory response is mounted, and phagocytic cells engulf damaged but still viable tissue.
Harmful chemicals damage the blood–brain barrier.
Cerebral oedema (swelling of the brain) occurs due to leakage of large molecules from blood vessels through the damaged blood brain barrier.
These large molecules pull water into the brain tissue after them by osmosis. This "vasogenic oedema" causes compression of and damage to brain tissue
231
Thrombus
Aggregation of platelets, fibrin, clotting factors and cellular elements of blood.
232
Embolus
A mass of undissolved matter that breaks off from the thrombus.
Has the ability to travel through the vascular system.
Can cause ischaemia, infarction and death.
233
Haemostasis
Homeostatic mechanism through which bleeding stops from damaged blood vessels and is achieved in three steps-
Vasoconstriction
Platelet plug formation
Blood coagulation
234
Blood coagulation
Involves two distinct processes. Intrinsic and extrinsic pathways
235
Intrinsic pathway of blood coagulation
Chemical substances involved in coagulation are normally found in circulating blood through this pathway.
Process occurs over several minutes.
236
Extrinsic pathway of blood coagulation
Activated within minutes secondary to trauma to vascular wall or tissue external to blood vessels.
Clotting occurs when thromboplastin (tissue protein) is released from damaged tissues and leaks into the bloodstream.
237
Anticoagulant therapy
Prophylactic treatment designed to prevent fibrin deposits.
Reduces the incidence of thrombosis and can prolong life.
This form of therapy has no effect on blood clots that have already formed.
Common anticoagulant medications include heparin and warfarin.
238
Anticoagulant therapy mechanism of action
Inhibit the production of vitamin K in the liver
| This increases the time it takes for blood to clot
239
Anti-platelet therapy
Decreases platelet aggregation and inhibits thrombus formation.
They are effective in the arterial circulation, where anticoagulants have little effect.
Platelets adhere to a thrombogenic surface and are activated by mediators such as platelet activating factor.
Common antiplatelet medications include aspirin and dipyridamole
240
Thrombolytic therapy
Converts blood plasminogen to plasmin.
Used to treat acute thromboembolic disorders.
Blockages can occur in major arteries or veins and can be life-threatening.
Thrombolytic drugs are most effective when they are initiated as soon as possible after the acute event, before permanent damage occurs.
241
Common thrombolytic medication
alteplase, reteplase, tenecteplase and urokinase
242
What are receptors
Molecule that receives chemical signals from outside a cell.
| When these chemical signals bind to a receptor, they cause some form of cellular/tissue response.
243
Types of receptors
Channel-linked receptors (ligand-gated ion channels)
Interaction of chemical signal causes the opening or closing of an ion channel
Enzyme-linked receptors
Extracellular binding site for chemical signals
Majority of these are protein kinases – phosphorylate intracellular target proteins
Change the physiology of the target cell
Intracellular receptors
Activated by cell-permeant or lipophilic signalling molecules
Activation of the signalling cascade that produces new mRNA and protein within target cell
244
What are inhibitors
Binds to an enzyme/molecule/cell and decreases its activity
Enzyme inhibitors
Blocking an enzymes activity can kill a pathogen or correct a metabolic imbalance
Many drugs are enzyme inhibitors
Three different types (competitive; non-competitive; substrate)
245
Competitive inhibitors
Lock and key method – active site
When correct substance fits lock it turns thus opening for the reaction to proceed
When the inhibitor fits lock it does not turn leading to a delay in the reaction
246
Non-competitive inhibitors
Molecule binds to the enzyme somewhere other than the active site
Changes the three dimensional structure
The regular substance can still attach but it no longer stabilised to provide the correct action
247
Substrate
Attaches but inhibits the enzymes activity
248
What are chemical reactions
A process that leads to the transformation of one set of chemical substances to another.
A rearrangement of the molecular or ionic structure of a substance.
249
Agonists
Activate their target by mimicking the actions of endogenous regulatory molecules.
250
Antagonists
Block their targets and block the action of endogenous regulatory molecules
251
What are enzymes
Biological catalysts that speed up chemical reactions in living organisms
More than 500 types
Some work outside of the cell
Some enzymes help to make new substances in the body
Some enzymes help to break down unwanted substances in the body
252
Stroke complications
Increased risk of infection
Suppression of the immune system, therefore less effective at defending against bacteria and leads to increased susceptibility to bacterial infections. Highest cause of death post stroke
253
What causes UTI in a stroke patient
```
Delayed diagnosis
Immunosuppression
Middle cerebral artery affected (frontal lobe)
Brain stem
Urine pooling in bladder
```
254
Urinary tract infection
Mostly occur in lower urinary tract (bladder and urethra)
| women at increased risk
255
Signs and symptoms of a UTI
```
Strong persistent urge to urinate
Burning sensation when urinating
Passing frequent, small amounts of urine
Urine appears cloudy
Urine appears red or bright pink in colour (blood in the urine)
Strong smelling urine
Pelvic pain
```
256
UTI in the kidneys (acute pyelonephritis)
```
Upper back and side pain
high fever
shaking and chills
nausea
vomiting
```
257
UTI in bladder (cystitis)
pelvic pressure
lower abdomen discomfort
frequent painful urination
blood in urine
258
UTI in urethra (urethritis)
Burning with urination
| discharge
259
Risk factors for UTI
Indwelling catheters
Pregnancy
Medical conditions
260
UTI causes
Bacteria:
Community acquired
E. coli
```
Hospital acquired:
P. aeruginosa
Serratia spp
Enterobacter spp
Gram-negative organisms
```
261
UTI treatment
Classification of UTI will determine which form of treatment will be undertaken.
Common antibiotic therapies for UTI:
Broad-spectrum antibiotics (penicillins)- Inhibits bacterial cell wall synthesis
Methenamine (hexamine) hippurate- Denaturation (loss of structure) of bacterial proteins
Nitrofurantoin- Broad-spectrum bactericidal agent
