LRTI Flashcards
what is acute bronchitis
- viral infection
- inflammation of the - trachea or bronchi
presents with a fever, acute cough 1-4 weeks
pneumonia: hospitalisation and mortality
pneumonia often results in hospitalisation and the chance of mortality in hospital is quite significant.
- Mortality depends on pre-morbid state or the severity of pneumonia
pneumonia: symptoms? early vs late?
early stages of pneumonia are quite non-specific
malaise myalgia- muscle pain fever chest pain cough- initially dry purulent sputum dyspnoea - if condition is bad enough
pneumonia: investigations
serum biochemistry and full blood count CXR - may give diagnosis blood cultures throat swab urinary legionella antigen HIV test sputum microscopy and culture- often not useful
what are blood cultures used for in pneumonia investigations
try to isolate organisms but it’s only positive in 25 % of patients
why is legionella a significant bacterium
it causes pneumonia or similar disease called Legionnaires’ disease
why is sputum microscopy and culture often not useful
because it’s often negative but if it does come back positive the results take a while to come back and in the meantime the patient has been treated with antibiotics
define the term ‘consolidation’ in the lung
lung tissue that has filled with liquid instead of air.
it is a radiologic term
what investigation is not carried out often for pneumonia
CT scan however you may come across it in a CT scan whilst looking for something else
common organisms that cause pneumonia infection
strep pneumoniae 39%
H.influenzae 5.2%
Legionella 3.4 %
staph aureus 0.8%
what is the most common scoring system to determine the severity of pneumonia
CURB 65
explain CURB 65
C confusion
U blood urea >7
R respiratory rate >30
B diastolic blood
pressure <60
65 age> 65
score of 1 for each
score out of 5 overall
3-5 high risk of death and need for (ITU intensive treatment unit)
what treatment is used for those with a CURB score 0-1
amoxycillin or clarithromycin/ doxycycline
what treatment is used for those with a CURB score 2
amoxycillin and clarithromycin or levofloxacin
what treatment is used for those with a CURB score 3-5
co-amoxiclav and clarithromycin or levofloxacin (if allergic to penicillin)
if pneumonia is more severe, what treatment options are available (4)
oxygen - if hypoxic
IV fluids - dehydration due to liver damage
CPAP
intubation and ventilation - very severe cases - tracheal tube inserted
what complications can come with pneumonia ie other conditions (9)
Resp failure - type 1 quite common
septicaemia - sepsis and shock
acute kidney injury
empyema- infection in the pleural space
lung abscess- collection of pus within cavity of lung
metastatic infection- organisms in the blood spread through body
Acute Respiratory Distress Syndrome (ARDS) - inflammatory complication
Atrial fibrillation -common in elderly usually resolves with treatment. Beta blocker or digoxin may be required to slow heart rate in short term
hypotension - due to dehydration/vasodilation due to sepsis
how is empyema investigated, diagnosed and treated
investigate using CT thorax and pleural ultrasound
diagnosed by sampling fluid in the pleural space
pH should be less than 7.2
treatment includes chest drain, IV antibiotics or surgery for patients not improving with this management
Empyema and pneumonia
may or may not follow documented episode of pneumonia
mostly caused by streptococcus and anaerobes
chest pain without cough
high swinging fever due to pus
lung abscess and pneumonia
may or may not follow pneumonia
symptoms are non specific - lethargy, weight loss, swinging fever
investigations and treatment for lung abscess
CT thorax and sputum culture including TB microscopy and culture
prolonged antibiotics
drainage is via bronchial tree but occasionally drainage through chest wall
What is bronchiectasis and what happens to the airways due to this condition?
Abnormal permanently dilated airways due to bronchial wall inflammation, thickening and irreversible damage
this causes a build-up of excess mucus that can make the lungs more vulnerable to infection as it can trap more bacteria
If an infection does develop, the bronchi may be damaged again, so even more mucus gathers in them and the risk of infection increases further.
airway walls thicken and the airways dilate even out at the periphery of the lung
causes of bronchiectasis
Idiopathic
Immotile Cilia Syndrome – cilia stop working - not common cause
Cystic fibrosis – commonest autosomal recessive condition
Childhood infections such as measles or whooping cough
Hypogammaglobulinaemia – don’t produce sufficient amount of antibodies to fight infection. Can be acquired or inherited
asthma
aspiration pneumonia
inhale own vomit
- leads to lung injury and resultant bacterial infection.
how does influenza cause complications with pneumonia
higher freq of staphylococcal pneumonia
staphylococcal pneumonia including PVL toxin
PVL toxin is rare - certain strains of staph aureus produce this toxin and this can cause quite a severe pneumonia
Haematological malignancy/neutropenia
complication with pneumonia
if you’ve had lymphoma or leukemia you will be immunosuppressed - don’t fight off infection so well- different spectrum of organisms- need to use broad spectrum antibiotics- also have to consider anti-fungal drugs
what is pneumococcal pneumonia?
what is used to treat it?
a type of pneumonia
commonest bacterial pneumonia
affects all ages but more common in elderly, alcoholics, post splenectomy, immunosuppressed and patients with chronic heart failure or pre-existing lung disease
amoxicillin
benzylpenicillin
cephalosporin
describe a bit about staphylococcal pneumonia
what is used to treat it?
may complicate influenza infection or occur in the young, elderly IV drug users or patients with underlying disease e.g leukaemia, lymphoma, CF
causes bilateral cavitating bronchopneumonia
flucloxacillin +/- rifampicin
MRSA - contact lab; maybe consider vancomycin
describe a bit about mycoplasma pneumoniae
How is it diagnosed? what is used to treat it?
occurs in epidemics
insidiously with flu-like symptoms followed by a dry cough
CXR reticular-nodular shadowing or patchy consolidation often of one lower lobe
diagnose:- PCR sputum or serology
treatment:- clarithromycin
doxygycline
fluroquinolone
legionella pneumophila
what is it?
diagnosis
treatment
mortality
flu like symptoms precede a dry cough and dyspnoea
anorexia
renal failure
confusion
coma
CXR shows bi basal consolidation
urinalysis may show haematuria
diagnosis: urine antigen/culture
treatment: fluoroquinolone
clarithromycin
10% mortality
viral pneumonia
influenze commonest
swine flu is now considere seasonal and covered by the annual flu vaccine
others: measles + varicella zoster
pneumocystis pneumonia
pnuemonia in immunosuppressed (HIV)
dry cough, exertional dyspnoea, decrease in partial pressure of arterial O2, fever
CXR may be normal or show bilateral peri-hilar interstitial shadowing
diagnosis: lung biopsy, sputum sample or bronchioalveolar lavage
treatment - high dose co-trimoxazole
pentamidine
steroid if severe hypoxaemia
Pneumonia in genera: definition signs symptoms diagnosis/innvestigation management
inflammation of the substance of the lungs usually due to bacterial infection
signs: pyrexia (fever), tachypnoea, central cyanosis, dullness of percussion of affected lobe (fluid), bronchial breath sounds (hollow), inspiratory crepitations (crackles), increased vocal resonance (denser or inflamed lung tissue)
symptoms: malaise, fever, pleuritic chest pain, cough, purulent sputum, dyspnoea
diagnosis/investigation: FBC and serum biochemistry CXR blood cultrues throat swab urinary legionella antigen sputum microscopy and culture
management: CURB 65
O2, CPAP, iv fluids
intubation/ventilation if any required
what is hypersensitivity pneumonitis?
definition signs symptoms diagnosis/investigation management
inflammatory reaction in small airways and alveoli due to inhalation of different antigens. Non- infectious
signs: abnormal CXR, tachypnoea, coarse end inspiratory crackles on auscultation, cyanosis.
If chronic - severe weight loss, idiopathic pulmonary fibrosis
symptoms- malaise, fever, cough, SOB
diagnosis/investigation:-
CXR - fluffy nodular shadowing
CT - reticular and nodular changes
PFT - ie spirometry - restrictive defect
Blood tests - IgG (Main one in blood)
precipitating antibodies present in serum
management - avoid allergen if possible, alter working practice if possible, manage symptoms with corticosteroids
define what the interstitium of the lung is
space between alveolar sacs and pulmonary arterioles
what 2 classes of antibiotics should be used to treat a patient with left lower lobe pnuemonia before a bacteriological diagnosis is reached?
Macrolides - Azithromycin, Clarithromycin
Beta - lactams
