Week 9 Flashcards
1
Q
What can be the cause of a CXR being too black or black in the wrong place?
A
Increased Translucency:
- Air (gas)
- Loss of tissue density
2
Q
What can be the cause of a CXR being too white or white in the wrong place?
A
Opacification:
- Fluid
- Increased tissue ie. lymphadenopathy
3
Q
What can be the cause of a CXR being really really white or very radio opaque?
A
Patient may have a pacemaker, Endotrachial tube, Nasogastric tube, Sternal wiring, CVP line, chest drain, prosthetic heart valves
4
Q
What is the definition of Consolidation?
A
Replacement of normal air space gas with fluid or solid material
5
Q
What are the 5 causes of consolidation and what can they be due to?
A
- Pus- infection (pneumonia)
- Blood- pulmonary haemorrhage
- Fluid- pulmonary oedema
- Cells- lung cancer
- Protein- alveolar proteinosis
6
Q
What is the definition of a collapsed lung or atelectasis?
A
Reduction in inflation of all or part of the lung
7
Q
What are the signs to look for on X-ray for a collapsed lung/atelectasis?
A
- Volume loss
- Displacement of trachea
- Displacement of diaphragm
- Displacement of lung fissures
- Compensatory over inflation of non collapsed lung
- Crowding of vessels & Bronchi
8
Q
What are the causes of a deviated trachea? (towards & away from pathology)
A
- Towards pathology: pneumonectomy/Lobectomy, lobar collapse
- Away from pathology: tension pneumothorax, massive pleural effusion
9
Q
In ABCDEFGH of examining a CXR what does A stand for?
A
AIRWAY:
- Trachea position and length
- Bifurcation of bronchi and main bronchi at T4
10
Q
In ABCDEFGH of examining a CXR what does B stand for?
A
BREATHING:
- Good inspiration the dome of right diaphragm should be between 5th-6th ribs
- Lung fields
- Opacities
11
Q
In ABCDEFGH of examining a CXR what does C stand for?
A
CARDIAC:
- Heart should be no more than 1/2 diameter of chest, 1/3 right of sternum, 2/3 to left
- Check what makes up the right and left borders
12
Q
In ABCDEFGH of examining a CXR what does D stand for?
A
DIAPHRAGM:
- Stomach bubble
- Below right diaphragm for free air
13
Q
In ABCDEFGH of examining a CXR what does E stand for?
A
EXTERNAL STRUCTURES:
- Ribs
- Thoracic spine
- Clavicles
- Scapulae
- Heads of both humeri
14
Q
In ABCDEFGH of examining a CXR what does F stand for?
A
FAT & SOFT TISSUE:
- Breast shadows
- Subcutaneous fat for signs of surgical emphysema
15
Q
In ABCDEFGH of examining a CXR what does G stand for?
A
GREAT VESSELS:
- Aortic arch, pulmonary arteries & veins
- Calcium deposits in elderly
16
Q
In ABCDEFGH of examining a CXR what does H stand for?
A
HIDDEN AREAS:
- Apices
- Mediastinum for widening ie. adenopathy, aortic dissection, mediastinal emphysema
- Behind heart for lingular pneumonia
17
Q
How do you calculate plasma pH?
A
pH = pKa + log[HCO3-] / [CO2]
18
Q
What is the definition of pKa?
A
pH at which 50% is ionised and 50% is unionised in the reaction
19
Q
H2CO3 ↔ HCO3- + H+
What happens to this equation if H+ rises?
A
Equation is driven to the left
20
Q
H2CO3 ↔ HCO3- + H+
What happens to this equation if H+ falls?
A
Equation is driven to the right
21
Q
What is the pKa for carbonic acid/bicarbonate?
A
6.1
22
Q
What is the normal pH for the body?
A
7.4
23
Q
If you increase CO2 what happens to H2CO3?
A
H2CO3 increases
24
Q
Where in the equation is Respiratory Acid-base disturbances/disorders?
A
CO2 + H2O
- Primary change is to CO2 levels
25
Where in the equation is Metabolic Acid-base disturbances/disorders?
H2 + HCO3
| - Primary change is to bicarbonate
26
What pH is defined as acidosis?
< 7.35
27
What pH is defined as alkalosis?
> 7.45
28
What are the 2 causes for acidosis?
1. Rise in PCO2
| 2. Fall in HCO3-
29
What are the 2 causes for alkalosis?
1. Fall in PCO2
| 2. Rise in HCO3
30
How is compensation achieved?
Lungs and kidneys may try return any acid-base disturbance towards normal
31
What are the ways that the lungs and kidneys can compensate?
1. Respiratory system alters ventilation, this happens quickly
2. Kidneys alter excretion of bicarbonate, this takes 2-3 days
32
What does Renal Compensation do during respiratory acidosis?
Increased HCO3 reabsorption and increased HCO3 production which raises pH towards normal
33
What are clinical causes of respiratory acidosis?
- COPD
- Blocked airway (foreign body/tumour)
- Lung collapse
- Injury to chest wall
- Drugs reducing respiratory drive ie. morphine, anaesthetics
34
What does Renal Compensation do during respiratory alkalosis?
Reduced HCO3 reabsorption & reduced HCO3 production, thus plasma HCO3 levels fall, compensating for lower H+, moving pH back towards normal
35
What are the clinical causes of respiratory alkalosis?
- Increased ventilation, from hypoxic drive in pneumonia, diffuse interstitial lung diseases, high altitude, mechanical ventilation
- Hyperventilation from brainstem damage, infection driving fever
36
What does metabolic acidosis result from?
Excess H+ in the body, which reduces HCO3- levels
37
What does Respiratory Compensation do during metabolic acidosis?
- Lower pH is detected by peripheral chemoreceptors, causes increase in ventilation which lowers PCO2.
- Bicarbonate equation driven to left, reducing HCO3- and H+ further.
- Decrease H+ drives pH up.
- Respiratory cannot fully compensate, H+ needs to be removed or HCO3- needs to be restored by kidneys (2-3days)
38
What are the clinical causes of metabolic acidosis?
- Loss of HCO3 from gut e.g. diarrhea
- Exogenous acid overload e.g. aspirin
- Endogenous acid overload e.g. ketogenesis
- Failure to secrete H+ e.g. renal failure
39
What does respiratory acidosis result from?
Increase in PCO2 caused by hypoventilation or ventilation/perfusion mismatch
40
What does respiratory alkalosis result from?
Decrease in PCO2 due to alveolar hyperventilation, decreasing H+, raising pH
41
What does metabolic alkalosis result from?
Increase HCO3 concentration or fall in H+
42
What does Respiratory Compensation do during metabolic alkalosis?
- Increase pH detected by peripheral chemoreceptors
- Decreases ventilation and raises PCO2
- Increase H+ & HCO3
- Renal response is to secrete less H+
43
What are the clinical causes of metabolic alkalosis?
- Vomiting, loss of HCl from stomach
- Ingestion of alkali substances
- Potassium depletion (diuretics)
44
What is Selective toxicity?
Toxicity of antibacterial is greater than it is to human
45
What are the bacterial cell wall inhibitor subclasses?
- Beta-Lactam
- Cephalosporin
- Glycopeptides
46
What group of cell wall inhibitors work by inhibiting synthesis of peptidoglycan?
Glycopeptides (e.g. vancomycin, teicoplanin)
47
What groups of bacterial cell wall inhibitors work by inhibiting cross linkage of peptidoglycan?
- Penicillins,
- Cephlosporins
- Carbapenems
- Monobactams
48
What 3 groups of pathogens can be treated by penicillins G & V?
1. Gram positive and Gram negative cocci
2. Gram positive rods
3. Spirochaetes
49
Give examples of beta lactamase resistant penicillins?
- Methicillin
- Oxacillin
- Nafcillin
- Dicloxacillin
50
Give examples of broad spectrum penicillins?
- Ampicillin
| - Amoxicillin
51
Give examples of extended spectrum antibiotics?
- Carbenicillin
- Ticaracillin
- Azlocillin
- Piperacillin
52
What bacteria do extended spectrum penicillins cover?
All of broad spectrum and Pseudomonas Aeruginosa
53
Describe Carbapenems?
- Broad spectrum
- Resistant to typical beta-lactamases
- Bind Beta-lactamases and acylate the enzyme inactivating it
54
What are Carbapenems poorly active against?
- MRSA
| - Bacteria lacking cell wall
55
What are the 3 main mechanisms of resistance in beta lactam antibiotics?
- Destruction by Beta-lactamase ie. s. aureus
- Failure to reach target enzyme due to changes in bacterial outer membrane porins and polysaccharide components of gram negative bacteria ie. pseudomonas Spp
- Failure to bind to transpeptidases ie. S. pneumoniae
56
What is an alternative approach to the use of Beta-lactamase-resistant antibiotics?
Co-administration of Beta-lactamase inhibitors & Beta-Lactam antibiotic
57
Describe Cephalosporins?
- Same as penicillins
- Classified by generation
- Cell wall inhibitor
58
What do Cephalosporins treat?
- Septicaemia
- Pneumonia
- Meiningitis
- Biliary tract infections
- UTIs
- Sinusitis
59
Give examples of cephalosporins?
- Cephalexin
- Cefuroxime
- Cefotaxime
- Cefadroxil
60
Describe Vancomycin?
- Glycopeptide antibiotic
- Binds to peptide chains of peptidoglycan & interferes with elongation of peptidoglycan backbone (D-ala-D-ala interaction is specific so little resistance)
- Cell wall inhibitor
61
What is Vancomycin usually used to treat?
- MRSA
| - Resistant Streptococci & Enterococci
62
Describe Bacitracin?
- Polypeptide
- Bactericidal (kills bacteria)
- Interferes with dephosphorylation of lipid carrier which moves the early cell wall components through the membrane
- Cell wall inhibitor
63
What can Bacitracin be used in?
Ointment to treat infections of skin & eye by Streptococci & Staphylococci
64
What are the main Bacterial Folate Antagonists?
- Sulphonamides
| - Trimethoprim
65
How do Bacterial Folate Antagonists work?
- Inhibit folate pathway in bacteria important in cell metabolism as bacteria can't ingest folate (selective toxicity as we take in through diet)
66
What is Trimethoprim commonly used for?
Community UTI's
67
What 2 antibiotics are combined to make Co-trimoxazole?
Sulphamethoxazole & Trimethoprim
68
What is Co-trimethoprim used to treat?
- Toxoplasmosis
- Opportunistic infections in AIDs
- Resistant salmonella & thyphoid
69
What 2 drugs are used in combination to treat drug resistant Malaria and Toxoplasmosis?
Sulphamethoxazole & Pyrimethamine
70
What are the main Macrolides?
Erythromycin & Clarithromycin
71
When are Macrolides used?
- Alternative to penicillin in sensitive patients
- Management of community acquired lower RTI
- Corynebacterium (diphtheria)
- Camphylobacter (diarrhea)
72
What are side effects of Erythromycin?
- Gut disturbances
- Hypersensitivity
- Transient hearing disturbances
- Rarely cholestatic jaundice
73
What are side effects of Clarithromycin?
- Gut disturbances
- Hypersensitivity
- Transient hearing disturbances
- QT PROLONGATION
74
What are side effects of Clindamycin?
- GI disturbances
| - Pseudomembraneous colitis
75
What are the uses of clindamycin (lincosamide class)?
- Against gram-positive cocci ie. staphylococci
- Wide range of anaerobic species ie. Bacteriosides sp.
- Combination against anaerobic sepsis, necrotizing fasciitis, staphylococcal infections of joints and bones
- Eye drop for staphylococcal conjunctivitis
76
Give examples of Aminoglycoside antibiotics?
- Streptomycin
- Gentomycin
- Kanamycin
- Neomycin
77
What conditions may Aminoglycosides be used to treat?
- Enterobacteriaceae and Pseudomonas (septicaemia and serious UTI)
- Hosptial aquired pneumonia, respiratory and intraabdominal infections due to Pseudomonas
78
What are common side effects of aminoglycosides?
- Renal toxicity due to damage of kidney tubules
- Ototoxicity with progressive destruction of sensory cells in cochlea and vestibular organ of the ear (vertigo, ataxia, loss of balance & auditory disturbances)
- Neuromuscular block
79
Describe the pharmacokinetics of Aminoglycosides?
- Polar agent confined to extracellular fluid
- Doesn't cross BBB
- Excreted by kidney
- IV administration
80
Describe the uses of Tetracylines?
- 1st choice in Mycoplasma & chlamydial infections, Lyme disease
- COPD
- Management of resistant gram-negative infection
- Chronic acne
81
What are side effects of Tetracyclines?
- Gut upsets
- Hepatic & renal dysfunction
- Photosensitivity
- Binding to bone & teeth causing staining
- Vestibular toxicity=dizziness
82
Describe Chloramphenicol?
- Broad spectrum
- Inhibits protein synthesis
- Only used in serious infections
83
What are the side effects of Chloramphenicol?
Rarely causes aplastic anaemia
84
What is Chloramphenicol used to treat?
Meningitis and brain abscesses when other agents cannot be used
85
What does Topioisomerease IV do?
- Involved in chromosomal partitioning
- Catalyses ATP dependent relaxation of negatively & positively supercoiled DNA and untknotting of unknicked suplex DNA
- No action against super-coiling
86
What does DNA gyrase do?
- Tetrameric enzyme consisting of 2 GryA and 2 GyrB subunits
- Transient covalent bond with DNA
- Breaking DNA & passing DNA through break
- Repairing the break
87
What is the spectrum of activities of Fluoroquinolone?
Ciprofloxacin most commonly used against Enetrobacteriaceae (gram -ve), H influenzae, N gonorrhoea, camphylobacter (diarrhoea), pseudomonas aeruginosa & salmonella
88
Name some Quinolone antibiotics?
- Naladixic acid
- Norfloxacin
- Ciprofloxaxin
- Moxifloxacin
- Gatifloxacin
- Gemifloxacin
89
Describe Metronidazole?
- Anaerobic conditions generates toxic radicals that damage bacterial DNA
- Active against anaerobic bacteria ie. Bactericides, Clostridia
- Treat anaerobic infections ie. sepsis secondary to bowel disease
- Treat pseudomembraneous colitis
- Used with other drugs (omeprazole, amoxicillin) to treat Helicobacter pylori infections which give rise to peptic ulceration
90
What spectrum of bacteria is Nitrofurans active against?
Broad Spectrum
91
How do Polymixins work?
Cationic detergent properties, interact with phospholipids of cell membranes, causing breach and loss of intracellular contents
92
What is the use of Nitrofurantoin?
UTI due to Enterobacteriaceae
93
What is the use of Polymixins?
Topical use for cutaneous Pseudomonas infections
94
What are the 2 main health hazards of hospitalisation?
1. HAI Infections (nosocomial) i.e MRSA, MSSA, E coli, C difficile - Can be reduced by implementation of hospital infection control guidelines
2. Bed Rest - deterioration in CV fitness, loss of muscle, problem in elderly
95
What can healthcare staff try and improve on for patients feeling a loss of control whilst in hospital?
- Behavioural control
- Cognitive control
- Decision control
- Informational control
96
What is the definition of "Depersonalisation"?
When your patient is treated as though he or she were either not present or not a person
97
What is the definition of "Institutionalisation"?
In normal life people adopt a variety of roles each day, in hospital the variety of roles decreases
98
Give a summary on the experience of being a patient?
- Unfamiliar environment
- Role of being a patient
- Complain about losing control
- Staff often depersonalise patients
- Institutionalisation if patient is in hospital for long period
99
What are the stages of separation anxiety in a hospitalised child?
1. Protest (upset, distressed)
2. Despair (withdrawn, hopelessness)
3. Detachment (behaviour returned to normal, child will reject primary care giver)
100
What are the impacts of hospitalisation on a childs behaviour?
- May regresses sharply
- Nightmares
- Irritable
- May not occur until returned home
- Misconceive illness
- Faulty illness representation
101
How can be improve experience of hospital for children?
- Day surgery/outpatient treatment
- Preparation for hospital
- Unrestricted parental visits
- Nursing staff supporting and educating parents to care for their child in hospital
- Reduce nursing staff dealing with particular child
- Communicate with child & Parent
102
What are the 3 Steps in Pasteur's Principle for vaccines?
1. Isolate
2. Inactivate
3. Inject
103
What are the essential characteristics of vaccines?
- Effective protection without risk of disease/severe side effects
- Long-lived protection
- Stimulate correct arm of immune response ie. antibodies, effector T cells
- Stimulate neutralising antibodies to prevent reinfection
- Stable for long-term storage and transport
- Affordable
104
What is a Live Vaccine?
Organisms capable of normal infection and replication. Not used against pathogens that can cause severe disease
105
What is a Attenuated Vaccine?
Organism is live, but ability to replicate and cause disease reduced by chemical treatment or growth-adaption in non-human cell lines (measles, mumps, rubella)
106
What is a Killed Vaccine?
Organism killed by physical or chemical treatment. Incapable of infection or replication, but still able to provoke strong immune response (B.pertussis, typhoid)
107
What is an Extract Vaccine?
Materials derived from disrupted or lysed organism ie. capsular polysaccharides. Used when risk of organism surviving inactivation steps (flu, pneumococcal, diptheria, tetanus)
108
What is a Recombinant Vaccine?
Genetically engineered to alter critical genes. Often can infect and replicate but does not induce associated disease
109
What is a DNA Vaccine?
Naked DNA injected. Host cells pick up DNA and express pathogen proteins that stimulate immune response
110
What is the most effective vaccines?
- Live / Attenuated
| - They express proteins and stimulate immune response closely resembling normal infection
111
What is Herd Immunity?
| What are the potential problems with it?
- You don't need to vaccinate all of the population (90-95%) because the unvaccinated people have a very slim chance of actually catching the disease
- Population remains essentially resistant
- Problems are that vaccination rates fall below 90-95% and disease rates can increase
112
What is the definition of DTaP/IPV/Hib Vaccinations?
Diptheria, tetanus, pertussis, inactivated Polio vaccine, haemophilus influenzae type B
113
What is the DTaP/IPV Vaccination?
Booster vaccine for diptheria, tetanus, pertussis, Polio
114
What is the Td/IPV Vaccination?
Booster vaccine for tetanus, diptheria, polio
115
When is the Pneumococcal Vaccination offered?
>65yr
116
When is the Flu Vaccination offered?
Elderly & at risk patients
117
When is the DTaP/IPV/Hib and MenC Vaccinations offered?
2,3,4 month olds (2 injections in total)
118
When is the MMR Vaccination offered?
~13months (1 injection)
119
When is the DTaP/IPV and MMR Vaccinations offered?
3yr 4month --> 5yr olds
| 2 injections in total
120
When is the Td/IPV Vaccination offered?
13yr --> 18yr old
| 1 injection
121
What is the problem with creating a vaccine for Meningococcus B?
- Capsular polysaccharide which would be target antigen of vaccine is very similar to sugar of NCAM- important neural membrane protein
- Antibodies could cause autoimmunity
122
What are Dendritic cells (DCs) ?
- Antigen presenting cells - Process antigen material & present it on the cell surface to T cells
- Act as messengers between the innate & adaptive immune systems
- Express Pattern Recognition Receptors (PRR) which are from Toll-like receptor family (TLR)
123
What is TLR4?
Lipopolysaccharide, heat shock proteins
124
Describe the 3 step process of dendritic cell function?
1. Encounters antigen in periphery, becomes activated
2. Migrates to lymph node
3. Activates T cells to become effector cells
125
What/ When is an Adjuvent used?
Added to vaccines to increase immune response to vaccine
126
What are the common (>50%) normal microbiota or the respiratory tract?
- Bacteroides spp.
- Candida albicans
- Oral Streptococci
- Haemophilus influenzae
127
What are the occasional (<10%) normal microbiota of the respiratory tract?
- Streptococcus pyogenes
- Streptococcus pneumoniae
- Neisseria meningitidis
128
What are the normal microbiota of latent state in tissues of respiratory tract?
- Herpes Simplex Virus type 1 (HSV)
- Epstein-Barr virus (EBV)
- Cytomegalovirus (CMV)
- Mycobacterium tuberculosis
129
What are the respiratory tract host defences?
- Saliva
- Mucus
- Cilia
- Nasal secretions
- Antimicrobial peptides
130
What is Acute Coryza/ Rhinitis/Common cold?
- Irritation & inflammation of the mucous membrane inside the nose
- Seasonal in early autumn & mid/late spring
(40% rhinovirus, 30% coronavirus)
131
How is the common cold transmitted?
- Aerosol
| - Virus-contaminated hands
132
What are the clinical features of the common cold?
- Tiredness
- Pyrexia
- Malaise
- Sore nose & pharynx
- Profuse, watery nasal discharge becoming mucopurulent (pus)
- Sneezing in early stages
- Secondary bacterial infection occurs in minority
- MILD, NO VACCINE!
133
What are the viral causative agents for Acute Pharyngitis & Tonsillitis?
- Epstein-Barr virus (EBV)
- Cytomegalovirus (CMV)
- Herpes Simplex virus type I (HSV-1)
- Rhinovirus
- Coronavirus
- Adenovirus
134
What are the bacterial causative agents for Acute Pharyngitis & Tonsillitis?
- Streptococcus pyogenes
- Haemophilus influenzae
- Corynebacterium dephtheriae
135
Describe Cytomegalovirus (CMV)?
- Transmission in body secretions & organ transplants
- Asymptomatic/mild
- Can be reactivated
- Diagnose IgM in blood
- Diagnose CMV pneumonitis CMV Ag in BAL
- Treatment with ganciclovir, foscarnet, cidofovir
136
Describe Epstein-Barr Virus (EBV)?
- Replicates in B lymphocytes (CD21 receptor)
- Causes glandular fever
- Transmitted in saliva & aerosol
137
What are the clinical features of Glandular Fever?
- Fever
- Headache
- Malaise
- Sore throat
- Anorexia
- Palatal petechiae
- Cervical lymphadenopathy
- Splenomegaly
- Mild hepatitis
138
How do you detect IgM antibodies for Glandular Fever (EBV)?
- Monospot test
| - If negative consider HIV conversion
139
How do you treat Glandular Fever?
- Not with antibiotics!
| - Contact sports/heavy lifting avoided during 1st month of illness until any splenomegaly has resolved
140
What can be the complications of Glandular Fever?
- Burkitt's Lymphoma
- Nasopharyngeal carcinoma
- Guillain-Barre Syndrome
141
Describe Tonsillitis?
- Streptococcus pyogenes
- Transmission aerosol
- Children mainly
- Can become asymptomatic carrier
- Treat with Penicillin
142
What are the clinical features of Tonsillitis?
- Fever
- Pain
- Enlargement of tonsils
- Tonsillar lymphadenopathy
143
What can be the complications of Streptococcus pyogenes?
- Scarlet fever
- Peritonsillar abscess
- Otitis media/sinusitis
- Rheumatic heart disease
- Glomerulonephritis
144
What are the clinical features of Parotitis?
SCHOOL-AGE & YOUNG ADULTS
- Fever
- Malaise
- Headache
- Anorexia
- Trismus (spasm of jaw)
- Pain & swelling
145
Describe Parotitis?
- Mumps virus
- Paramyxovirus family
- Transmission by droplet spread & fomites
- Diagnosed by IgM serology performed from saliva, CSF/Urine
146
What are the Treatments for Parotitis?
- Mouth care
- Nutritional
- Analgesia
147
What can be done to prevent Parotitis?
MMR vaccine
148
What can be the complications of Parotitis?
- CNS involvement
| - Epididymo-orchitis (~30% infected after puberty)
149
Describe Acute Epiglottitis?
- Haemophilus influenza
- Young children
- Hib vaccine prevents it
150
What are the clinical features of Acute Epiglottitis?
- High fever
- Massive oedema of epiglottis
- Severe airflow obstruction
- Bacteraemia
151
How do you diagnose Acute Epiglottitis?
DONT examine throat/take swabs as this will precipitate complete obstruction of airway
152
What is the treatment for Acute Epiglottitis?
- EMERGENCY
- Urgent endotracheal intubation
- Intravenous antibiotics (ceftriaxone/chloramphenicol)
153
Describe Diphtheria?
- Rare
- Children
- May affect adults in countries where childhood vaccination is poor
- 3-5% of healthy throats
- Incubation period 2-7days
154
What are the clinical features of Diphtheria?
- Sore throat
- Fever
- Formation of pseudomembrane
- Lymphadenopathy
- Oedema of anterior cervical tissue (bull-neck)
155
How do you diagnose Diphtheria?
Made on clinical grounds as therapy is usually urgently required
156
What is the treatment for Diphtheria?
- Anti-toxin therapy intramuscularly
- Concurrent antibiotics (penicillin/erythromycin)
- Strict isolation
157
How do you prevent Diphtheria?
- Immunisation with toxoid vaccine
| - Booster doses given if travelling
158
Describe Laryngitis & Tracheitis?
- May spread down from URT
| - Viral origin (parainfluenza, respiratory syncytial, influenza virus & adenovirus)
159
What are the clinical features of Laryngitis & Tracheitis in adults?
- Hoarseness
| - Retrosternal pain
160
What are the clinical features of Laryngitis & Tracheitis in children?
- Dry cough
| - Inspiratory stridor (croup)
161
Describe Whooping Cough?
- 90% children <5
- Uncommon in developed countries
- Transmission aerosol
- Incubation period 1-3 weeks
162
What are the clinical features of Whooping Cough at catarrhal stage (1 week)?
- Highly contagious
- Malaise
- Mucoid rhinorrhoea
- Conjunctivitis
163
What are the clinical features of Whooping Cough at Paroxysmal stage (1-4 weeks)?
- Sudden attack of coughing with inspiratory "whoop"
| - Lumen of respiratory tract compromised by mucus secretion & mucosal oedema
164
How do you diagnose Whooping Cough?
- Characteristic "whoop"
- Bacterial isolation from nasopharyngeal swabs
- NAAT
165
How do you treat Whooping Cough?
- Catarrhal stage: erythromycin
- Paroxysmal stage: antibiotics have NO effect
- Isolation
- Supportive care
166
How do you prevent Whooping Cough?
Whole cell vaccination
167
What is Bordetella pertussis?
- Gram negative aerobic coccobacillus
- Attaches & replicated in ciliated respiratory epithelium
- NO invasion of deeper structures
- Specific attachment due to surface components i.e. filamentous haemagglutinin (FHA)
168
What are the toxic factors of Bordetella pertussis?
- Pertussis toxin (Ptx)
- Adenylate cyclase toxin
- Tracheal cytotoxin
- Endotoxin
169
Describe Acute Bronchitis?
- Inflammation of tracheobronchial tree
- Rhinovirus, Coronovirus, Adenovirus, Mycoplasma pneumoniae
- Secondary infections: Streptococcus pneumoniae, Haemophilus influenzae
170
Describe Chronic Bronchitis?
- Cough & excessive mucus secretion in tracheobronchial tree
- Anatomical disturbance of respiratory system
- Immune deficit: SCID
- Ciliary deficit: Kartegener syndrome, smoking
- Excessively thick mucus: CF
171
Describe Pneumonia?
- Inflammation of the substance of the lungs
- Lower respiratory tract by inhalation of aerosolised microbes / aspiration of normal flora of the upper respiratory tract
172
What is the cause of Pneumonia in children?
- Mainly viral
| - Neonates may develop pneumonia caused by Chlamydia trachoma's acquired from mother during birth
173
What is the cause of Pneumonia in adults?
Mainly bacterial
174
List the common causes of Viral Pneumonia
- Influenza virus
- Measles
- Coronavirus
- Parainfluenza virus
- Respiratory syncytial virus (RSV)
- Cytomegalovirus (CMV)
- Adenovirus
175
List the common causes of Bacterial Pneumonia?
- Streptococcus pneumoniae
- Mycobacterium tuberculosis
- Haemophilus influenza
- Pseudomonas aeruginosa
- Staphylococcus aureus
176
What is Atypical Pneumonia?
| Give examples?
FAILURE TO RESPOND TO PENICILLIN
- Mycoplasma pneumonia
- Legionella pneumophilia
- Chlamydia psittaci
- Chlamydia pneumoniae
- Coxiella burnetii
177
What is Lobar Pneumonia?
Involvement of distinct region of the lung ie. lobe
178
What is Bronchopneumonia?
- Diffuse, patchy consolidation
| - Associated with bronchi & bronchioles
179
What is Interstitial Pneumonia?
- Invasion of lung interstitium
| - Usually characteristic of viral infection
180
What is Necrotising Pneumonia?
Lung abscesses & destruction of parenchyma
181
What are the clinical features of Streptococcus Pneumoniae?
```
INITIALLY:
- Abrupt onset
- Rigors
- Fever
- Malaise
- Tachycardia
- Dry cough
FOLLOWED BY:
- Productive cough and rusty sputum
- Spiky temp
- Lobular consolidation
```
182
What are the clinical features of Mycoplasma Pneumoniae?
- Fever
- Dry cough
- Dyspnoea
- Lymphadenopathy
183
What are the clinical features of Haemophilus Influenzae?
- Mainly children
- Consolidation/patchy bronchopneumonia
- Persistent purulent sputum & malaise
184
How is Pneumonia diagnosed?
Chest X-ray
185
Describe Legionnaires disease?
- Legionella pneumophila
- Secretes protease causing lung damage
- Transmitted by aerosol, not person-person
- Outbreaks
186
What are the clinical features of Legionnaires disease?
- Tachypnoea
- Purulent sputum
- Chest X-ray consolidation
187
How is Legionnaires Disease diagnosed?
- Gram staining of sputum
- Recognition with serotype-specific fluorescent antibody
- Culture of Legionella on cystine yeast extract agar
- Detection of antigen in urine
- 4-fold rise in antibody
188
Describe Measles?
- Paramyxovirus
- Spread via aerosol
- Multisystem infection
- Replicates in Lower respiratory tract
- Incubation 10-14days
- May result in neurological complications
- Can cause "giant cell" pneumonia in immunocompromised
189
What are the clinical features of Measles?
- Fever
- Runny nose
- Koplik's spots
- Characteristic rash
190
How do we diagnose Measles?
- Serology for measles-specific IgM
- Virus isolation
- Viral RNA detection
191
How do you treat Measles?
- Severe: ribavirin treatment
| - Antibiotics for secondary bacterial infections
192
How do you prevent Measles?
Live, attenuated MMR vaccine
193
Describe Influenza Virus?
- Orthomyxovirus
- There are 3 types
- Type-specific antigen on cell surface (spikes)
- Single-stranded RNA
194
What are the 3 types of Influenza Virus?
- Type A: epidemics & pandemics, animal reservoir
- Type B: epidemics, no animal hosts
- Type C: minor respiratory illness
195
What are the 2 type-specific antigens on cell surface of an Influenza Virus?
- Heamagglutinin (H)
| - Neuraminidase (N)
196
What happens to Influenza Virus during Antigenic Drift ?
- Small point mutations in H & N antigens occurs constantly
- Allows virus to multiple in individuals with immunity to preceding strains
- New subtype can re-infect community
- Occurs with all influenza types
197
What happens to Influenza Virus during Antigenic shift?
- Sudden major change based on recombination between 2 different virus strains when they infect the same cell
- Produces virus with novel surface glycoproteins
- New strain can spread through previously immune populations= new pandemic
198
What makes a pandemic?
- Antigenic shift
- Most people have no immunity
- Attack rate is high
- Mortality can be high
- Spreads rapidly
199
How do you diagnose Influenza?
```
Nasopharyngeal aspirate:
- Direct immunofluorescence
- Culture
- NAAT detection
Serum:
- Serology
```
200
How do you treat Influenza?
- Amantadine
- Zanamavir
- Oseltamivir ("Tamiflu")
201
How do you manage Influenza?
- Rest, warmth, hydration, analgesia
- Anti-viral treatment within 48hrs
- Antibiotics for secondary bacterial infection
202
How do you prevent Influenza?
- Killed vaccine ~70% efficacy
| - Different strains of antigen each year in anticipation of latest strain to emerge so need different vaccine each year
203
Describe Swine Flu?
- H1N1 virus
- Older people infected
- Vaccine had contained H1N1 components
- Infection largely limited to <40years
- Attack rate high but mortality low because of immunity
204
What does "SARS" stand for?
Severe Acute Respiratory Syndrome
205
What are the clinical features of SARS?
- High fever
- Cough
- Shortness of breath
- CXRs consistent with pneumonia
206
How is SARS transmitted?
| What is SARS incubation period?
- Droplets, faeces, infected animals
| - 2-7days
207
What is SARS-associated Coronavirus (SARS CoV)?
- Enveloped
- RNA virus
- Characteristic "halo"
- Receptor for spike protein is ACE2
208
What is SARS-associated Coronavirus (SARS CoV) identified by?
- Virus isolation in cell culture
- Electron microscopy
- Molecular techniques
209
How do you treat SARS?
- Ribavirin
- Corticosteroids
- Interferons
- Anti-retroviral therapies ie. protease inhibitors
- Whole inactivated virus vaccine & recombinant vaccine now developed
210
What is Tuberculosis (TB) associated with?
- AIDS
- Increased use of immunosuppressive drugs
- Decreased socio-economic conditions
- Increased immigration from areas of high endemicity
- Multiple drug resistance (MDR)
- Overcrowding & poor nutrition
211
What bacteria causes Tuberculosis?
Myobacterium tuberculosis
212
What are the clinical features of Primary Tuberculosis?
- Usually symptomless
- Cough & Wheeze
- Small transient pleural effusion
213
What are the clinical features of Miliary Tuberculosis?
- Acute diffuse dissemination of bacillus
| - Fatal without treatment
214
What are the clinical features of Post-Primary Tuberculosis?
- Onset of symptoms over weeks/months
- Malaise
- Fever
- Weight loss
- Mucoid, purulent or blood-stained sputum
- Pleural effusion
215
How do we diagnose Tuberculosis?
MANTOUX TEST:
- Latent TB infection
- Tuberculin injected intradermally
- Immune response if previously exposed to bacterium
- Induration (palpable hardened area) measured after 48-72hrs
216
How is bacterial growth measured on cultures?
Actively respiring bacteria consume O2 from media allowing fluorescence to be detected
217
How do you treat Tuberculosis?
```
Combination therapy:
- Isoniazid, ridampicin, ethambutol, pyrazinamide
Prolonged therapy:
- Min 6months
- Eradicate slow-growing organisms
```
218
How do you prevent Tuberculosis?
- Childhood immunisation
- Live, attenuated BCG vaccine (Bacille Calmette-Guerin)
- Prophylaxis with isoniazid for 1yr
219
What bacteria cause Fungal infections?
- Aspergillus fumigatus
| - Pneumocystis jiroveci
220
List 4 Parasitic infections?
- Ascaris
- Strongyloides
- Schistosoma
- Echinococcus granulosus
221
List some smoking related lung diseases?
- COPD
- Emphysema
- Chronic Bronchitis
222
What are the 2 types of emphysema and describe them?
1. Centrilobular (localised)- primarily the upper lobes. Loss of respiratory bronchioles in proximal portion of acinus. Typical for smokers.
2. Panacinar (unlocalised)- all lung fields, particularly bases. Loss of all portions of acinus (respiratory bronchiole --> alveoli)
223
List 3 Interstitial lung diseases?
1. Hypersensitivity pneumonitis
2. Sarcoidosis
3. Idiopathic pulmonary fibrosis (UIP)
224
Describe Hypersensitive pneumonitis?
| extrinsic allergic alveolitis
- Inflammation of alveoli within lung caused by hypersensitivity to inhaled organic dusts
- Type III and IV
- Bird fancier
- Farmers lung
225
Describe Sarcoidosis?
- Small patches of red and swollen tissue, called granulomas
- Cell mediated
- US black>white
- Granulomas
- Hilar lymphadenopathy
- Raised angiotensin converting enzyme
226
Describe Idiopathic pulmonary fibrosis (UIP)?
- Lungs become scarred and breathing increasingly difficult
- Post Viral?
- Other systemic disease
- Part of a spectrum?
- Honeycomb lung
227
Give examples of Benign Lung Tumours?
- MESENCHYMOMA
- Papilloma
- Inflammatory myoblastic tumour
228
Give examples of Primary Malignant Lung Tumours?
- EPITHELIUM (metaplasia/dysplasia)
- Vessels
- Muscles
- Cartilage
- Lymphoid
- Pleura
229
What is metaplasia & Dysplasia?
- Metaplasia: change of 1 mature cell type to another mature cell type
- Dysplasia: enlargement of organ/tissue by proliferation of cells of an abnormal type
230
Give examples of Secondary Malignant Lung Tumours?
- Sarcoma
- Renal Carcinoma
- Lymphoma
231
Give examples of Primary Epithelial malignant lung tumours?
- Squamous
- Adeno (glands)
- Small cell undifferentiated
- Carcinoid
- Large cell undifferentiatied
232
List how you can diagnose Primary Epithelial lung tumours?
- Radiology
- Cytology
- EBUS (Endobronchial ultrasound)
- Biopsy
- Grade
- Stage TNM
233
Describe Squamous Epithelial Malignant Lung Tumours? (NSCLC)
- Non-small cell lung cancer is a disease in which malignant cells form in tissues of lung
- ~40%
- Risk in Smoking, Air pollution, Asbestos
- Fibrosing lung disease
- TNM
234
Describe Adenocarcinoma Lung Tumour? (NSCLC)
- ~40%
| - Risk in Smoking, Lung scar, Air pollution, Asbestos
235
Describe Adenocarcinoma-bronchoalveolar Lung Tumour? (NSCLC)
- Variant of adenocarcinoma
- Pattern of spread
- Intrapulmonary dissemination
236
Describe Small Cell Undifferentiated Lung Tumours (SCLC)?
- Neuroendocrine
- Paraneoplastic effects: may produce bioactive amines or peptides i.e. ADH, PTN-like peptides, ACTH
- Neurological ie. demyelination
237
What is NSCLC?
- Non-small cell lung cancer - A disease in which malignant cells form in tissues of lung
238
Describe Carcinoid Lung tumours?
- Malignant spectrum
- "Typical" towards less aggressive end of spectrum
- "Atypical" smoking related, tends towards malignant end of spectrum
239
Describe Mesothelioma Lung Tumours?
- Asbestos: crocidolite
- Incidence rising
- Long lag period 20-40yrs
- Male:Female 5:1
- Significance of fibrous pleural plaques
240
What is the main form of primary malignant lung tumours?
Epithelium
241
What does staging refer to in terms of tumour?
TNM staging
| Tissue, lymph Nodes and Metastasis
242
What does grade refer to in quantifying tumours?
Amount of differentiation (undifferentiated being abnormal, primitive and aggressive)
243
What may Carcinoid tumours produce?
Amines such as noradrenaline resulting in panic attack
244
How many mmHg does 1kPa equal?
7.5mmHg
245
What buffers the pH in the body?
- Proteins
- Haemoglobin
- Carbonic acid and Bicarbonate
246
Where is acid/base excreted?
- Lungs
| - Kidneys
247
Which 3 scenarios result in disturbances in acid base balance?
- Problems with ventilation
- Problems with renal function
- Overwhelming acid/base load that body can't handle
248
What is the body's normal pH value?
7.35-7.45
249
What is the body's normal pO2 value?
12-13kPa
250
What is the body's normal pCO2 value?
4.5-5.6kPa
251
What is the body's normal bicarbonate value?
22-26mmol/l
252
Give 2 examples of endogenous acids?
- Ketoacidosis
| - Lactic acidosis
253
Give 2 examples of exogenous acids?
- Methanol
| - Aspirin
254
Which test is used to check arterial sufficiency to the hand?
Allan's test
(hand elevated & patient clench their fist ~30secs. Pressure applied over ulnar & radial arteries. Still elevated, the hand is then opened)
255
What is the difference between Actual v Standard Bicarbonate?
Standard bicarbonate is calculated from the actual bicarbonate but assuming 37oC and a pCO2 of 5.3kPa
256
If CO2 is high, how will bicarbonate be affected?
Increased
257
What is Step 1 in assessing acid/base balance?
Assess the oxygenation & look at pO2
258
What are the different adverse effects of high O2 levels?
- Increases risk of hypercapnic (abnormally elevated CO2) respiratory failure in acute exacerbations of COPD
- Increased mortality in survivors of cardiac arrest, intestine care patients, acute severe asthma
- Generates free radicals causing lung problems
- Ocular toxicity
- Myocardial damage
- Neuro damage
259
What can a high pO2 do to the lungs?
- Lung toxicity
- Collapse of alveoli due to atelectasis
- Irritating to mucous membranes
260
What is the normal target range of O2 saturation?
94-98%
261
What is the target range for O2 saturation in patients with type 2 respiratory failure?
88-92%
262
What are the 2 therapeutic uses of high inspired concentration of O2?
- Pneumothorax
| - Carbon monoxide poisoning
263
What may result in low O2 saturation but high O2 intake?
Problem with oxygenation (alveolar arterial gradient)
264
What is the normal Alveolar-arterial (A-a) gradient in kPa?
<3kPa
265
What fraction should the arterial pO2 be of the inspired pO2 in a fit healthy adult?
(PaO2/FiO2)
2/3
266
What else is the PaO2/FiO2 ratio known as?
P/F ratio
| kpa divided by inspired fraction of O2
267
What is the P/F ratio of a healthy person?
>50
268
What is the P/F ratio of a person with acute leg injury?
<40
269
What is the P/F ratio of a person with acute respiratory distress (ARDS)?
<26.7
270
What is Step 2 in assessing acid/base balance?
Assess pH
271
What is the pH of acidaemia?
<7.35
272
What is the pH of alkalaemia?
>7.45
273
What is Step 3 in assessing acid/base balance?
Determine the primary problem
274
If pH and pCO2 are changing in the opposite direction what does this suggest?
Respiratory problem
275
If pH and pCO2 are changing in the same direction what does this suggest?
Metabolic problem
276
What is Step 4 in assessing acid/base balance?
Is compensation occuring?
277
What is Compensation?
Altering of function of the respiratory or renal system in an attempt to correct an acid-base imbalance
278
Can the body ever overcompensate?
NO
279
If CO2 and bicarbonate move in the same direction what does this usually indicate?
Compensation is possibly occuring
280
If pCO2 and bicarbonate move in opposite directions what does this indicate?
More than 1 pathology is present
281
In chronic respiratory acidosis what is the compensation?
Kidneys retain bicarbonate (takes a few days to reach maximal value)
282
What are 4 possible causes of hyperventilation?
1. Acute severe asthma
2. Pulmonary embolism
3. Pulmonary oedema
4. Anxiety attack
283
What can cause an abnormal level of central respiratory drive?
- Hypoxia
- Stimulation lung mechanoreceptors/chemoreceptors
- Direct stimulation of respiratory centre
- Psychogenic
284
In what 2 situation may chronic respiratory alkalosis occur?
1. High altitude- hypoxaemia induced
| 2. Hyperventilation- compensation occurs by renal excretion of bicarbonate
285
Why do you look at the pO2 first?
Because hypoxia kills a patient the fastest
286
Can O2 be used as a treatment for hypoxia and dyspnoea?
Hypoxia- YES
| Dyspnoea- NO
