Week 118 Bronchial sepsis Flashcards
What is pleuritic chest pain?
Sharp pain on inhalation/movement like a bad stitch
What are rigors?
Feeling cold with a temperature/sweats and vice a versa
If a pt has recently been on holiday, what is this significance of this?
TB
Certain pathogens
What is palmar erythema and what is it significant of?
Red palms
Vasodilation because of shock with low bp
What are causes of low bp?
Bleeding Shock- sepsis or anaphylactic Endotoxic shock Pump failure Tablets (hypovolemia)
If a pt had a haemorrhage, how might their palms appear?
White and clammy
What do crackles sounds like?
Velcro
What does pleural rub sound like?
Someone walking on snow
How do you know if RLZ is affected? (CXR)
Can’t see diaphragm border
How do you know if right middle zone (lingular) is affected (CXR)?
Can’t see right heart border
What is a white-ish shadow potentially on a CXR?
Consolidation
How many ribs should be seen on a CXR?
8 anterior
6 posterior
What are signs of type 1 respiratory failure?
Low o2 low co2
What are signs of type 2 resp failure?
Low o2 high co2
What is CRP?
Protein made in liver, over 100 indicates infection/inflammation
What type of resp failure is pneumonia?
Type 1
What is high d-dimer indicative of in blood results?
Blood losing ability to clot so bruising and bleeding occurs e.g. overdose, kidney/liver failure
What is the average tidal volume?
500ml
How much air is processed in the lungs a day?
10-20,000 L
Describe features of typical pneumonia
- Abrupt onset
- High fever
- Purulent sputum (green)
- Focal consolidation
Describe features of atypical pneumonia
Gradual onset
Dry cough
Myalgias
Headache
When do you see helminths/protozoa infecting people?
Africa (sub-saharan), Asia
Immune deficient
What colour do gram +ve bacteria stain?
Blue
Describe features of streptococcus pneumonia
•Gm +ve •Lives in resp tract •Rapid multiplication •Abrupt onset •Very ill •Medical emergency community acquired/aspiration
mild- amoxicillin
moderate- am and clarithromycin
aspiration- CephalosporinIV+metronidazoleIV
What presents on a CXR differentiating pneumonia from cancer?
black dots (bronchal…? research)
Describe features of haemophilus influenza
BACTERIA heamophilus lives in mouth, nose, doesnt cause massive infection- weak bug that grows over a few days •URTI common •Usually encapsulated (typeable forms) •Small pleural effusions can occur •Empyema / cavitation rare
community acquired- clarithromycin
Where does staphylococcus normally grow?
Hands
Describe features of Staphylococcus aureus
-common in anyone with breakage in skin e.g. drug addict- look for needle marks
•Gram +ve
•Spread via airways (viral) or •Bacteraemia (e.g. endocarditis)
•Lung tissue lysis leads to cavitation
•Septicaemia, empyema, abscesses are common
Describe features of Klebsiella
•Gram –ve (not blue) •Colonise oropharynx •Nosocomial nosocomial= nursing home old people cant fight this off and have comorbidity •Comorbidity common •Very ill •Haemoptysis •Poor prognosis not dark blue stain
lives in stomach, intestines, oropharynx
Describe features of Escherichia coli
lives in gut- association with comorbities, aspiration
poor prognosis because already ill and unwell
- Gram –ve
- Comorbidity
- Chronically ill patient •Aspiration
- Often lower lobes
- Poor prognosis
Why is infection more common in right, lower lobe?
comes in lower lobe because of gravity - if you aspirate will go down
most common in RLL because right main bronchus is wider and more vertical and more likely to get infection in
Why can you see an endotracheal tube on an xray?
Has metal on it
Describe features of Pseudomonas aeriginosa
- Gram –ve
- Chronically ill
- Structural lung disease •Gradual onset
- Copious very green sputum
Describe features of Legionella pneumophilia
- Gram –ve intracellular
- Water / air con •Immunosupressed
- Dry cough, fever, myalgia,diarrhoea, rash •Oliguria, ARF, rhabdomyolysis, HSM
- 5-30% mortality
Mycoplasma pneumoniae
- Closed populations
- 50% URTI
- Arthralgias, LNs, myalgia, diarrhoea, myocarditis, meningitis, hepatitis, IHA, skin eruptions, vomiting
Chlamydia psittacci
•Intracellular bacterium •Inhalation from birds
•Fever, myalgia, macular rash, splenomegaly, severe cough, dyspnoea, depression
•1% mortality
•Lower lobe infiltrates, persist 4-6 weeks
Prolonged treatment
Mycobacterium tuberculosis
•Complex pathogen!
•Foreign travel, immunocompromised •Gradual onset, fever, chest pain, weight loss, dry cough, haemoptysis
•Cavitation, effusion, miliary •Highly infectious
A great mimic
Pneumocystis carinii
- Fungus? •Immunocompromised •Progressive SOB, dry cough, fever, weight loss
- Often minimal signs
- CXR anything!
Fungal (aspergillus,cryptococcus)
- Immunocompromised •Similar to bacterial pneumonia
* Cavitation common •Haemoptysis, weight loss •Poor prognosis
Order bacterial organisms causing pneumonia from most common to least
Step Pneum H. Influenza Staph Aureus Gm -ve Anaerobes
What organisms infect healthy individuals?
Strep pneum Outbreak Water Birds Occupation
What organisms infect hospitalised pts?
Gram -ve
Staph aureus
MRSA
What organisms infect immunocompromised pts?
PCP
TB
Fungal
Describe the Bohr effect
O2 curve changing= Bohr effect
Shift to right= ^co2 or reduced pH - acid drives off o2 from Hb at any given p02
right shift= blood gives off more o2 that it would because it encounters co2 and acid from metabolising tissues
Bohr effect assists o2 delivery
Describe what 2,3 BPG does
BPG- shifts curve to right
Purified Hb= far left therefore without BPG wouldn’t let fo of 02
BPG conc rises as anaemia develops to maintain o2 delivery to tissue
BPG prevents channel from becoming narrow
Stabilises dHb and shifts curve to right, improving o2 delivery
What are the most common hospital-acquired organisms for pneumonia?
Most commonly Gram negative enterobacteria or Staph. aureus.
Also Pseudomonas, Klebsiella, Bacteroides, and Clostridia.
Describe causes of pnuemonia
Community acquired
Hospital acquired
Aspiration
Immunocompromised pt
Aspiration Those with stroke, myasthenia, bulbar palsies, consciousness (eg post- ictal or drunk), oesophageal disease (achalasia, reflux), or with poor dental hygiene risk aspirating oropharyngeal anaerobes.
What defines severity of pneumonia?
Confusion (abbreviated mental test ≤8); Urea >7mmol/L; Respiratory rate ≥30/min; BP <90 systolic and/or 60mmHg diastolic); age ≥65. 0–1 home possible; 2 hospital therapy; ≥3 severe pneumonia indicates mortality 15–40%—consider ITU.
Confusion Urea Resp rate Bp Age
What are complications of pneumonia?
Pleural effusion, empyema, lung abscess, respiratory failure, septicaemia, brain abscess, pericarditis, myocarditis, cholestatic jaundice. Repeat CRP and CXR in patients not progressing satisfactorily.
Treatment for pneumonia
Breathing (o2)
Antibiotics (underlying cause)
Pain (analgesics)
Pneumococcal vaccines (for diabetics, those over 65)
What is needed for the lungs to function well?
- lots of air volume
- lots of tubes
- lots of blood
- lots of SA
- moisture and something to stop the thin walls from sticking together
What system/tract does the resp system develop from?
Gut tube, gi tract
foregut: (at level of future oesophagus) tracheosophageal septum develops from it and becomes bronchial buds
Describe the development of the lining of the airways
Lungs are lined by epithelium derived from endoderm (like the epithelium of the gut tube).
The lung bud is covered in splanchnopleuric mesoderm - will become connective tissue, muscle and cardiovascular structures of the lungs.
How do the lung buds develop?
The bud starts with 2 branches which will be the main bronchi (primary bronchial buds).
Then those branches branch to give the lobar bronchi (secondary bronchial buds)
left side gives 2 lobar branches and the right side gives 3 (evolutionary)
Describe the pseudoglandular stage
bronchial tubes branch, and branch, and branch.
- most about of surface area development here
What are the first cells to appear off the bronchial tree?
Primitive and type II pneumocytes (alveolar cells)
Why do we have smooth muscle in the airways?
Remnant of GI tract- we dont need it, hence becomes a problem in asthma
What divides the single cavity within the embryo into 2?
Septum transversum
What is a congenital hiatus hernia?
Diaphragm doesnt form properly so the intestines push up and stop the lungs growing
What are primitive alveoli?
Tubes bud sacs
Describe primitive alveoli
Epithelia of primitive alveoli thin and become type 1 pneumocytes (or squamous alveolar cells) with capillaries inside
What are type II pneumocytes?
Secrete surfactant
develop after type I from week 24 onwards
What is the function of surfactant?
reduces the surface tension of the fluids in the alveoli and stops the thin walls of the alveoli from sticking to each other (would make breathing difficult and gas exchange inefficient)
give artificial if premature
Name 5 stages of lung development and what develops
Embryonic
3-5 weeks
bud, branching
Pseudoglandular
6-16 weeks
Branching
Canalicular
17-24 weeks
terminal bronchioles
Saccular
25 weeks to term
primitive alveoli and capillaries
Alveolar
8 months to childhood
more alveoli
What is respiratory distress syndrome?
Not enough surfactant
atelectasis (lung collapse)
How is respiratory distress syndrome treated?
steroids, surfactant therapy, oxygen therapy, CPAP
premature mum may be given injection of steroids 24 hours before birth
How are fistulas formed?
Oesophagus and trachea remain linked
oesophagus ends abruptly
What is a complication of a fistula
Pneumonia may occur after birth as fluid may enter trachea through oesophageal fistula (surgery required).
A blind ending oesophagus can lead to polyhydramnios (too much amniotic fluid as it can’t be swallowed by the foetus).
What layer of the embryo does the respiratory tract arise from?
Endoderm
What phase is where branching of the bronchial tree most occurs?
Psuedoglandular
What is a primary limiter of gas exchange in lungs of a baby born at 28 weeks?
Limited alveolar surface area
What type of cell is a type I pneumocyte?
Squamous
What increases risk of respiratory distress syndrome in preterm infants?
Caesarean delivery
Which is most associated with deaths in the UK?
A. Pharyngitis
B. Laryngitis
C. Epiglottitis
D. Sinusitis
pharyngitis
3 year old boy is brought to you by his mother (who works at the local nursery). He has had 24 hours of intermittent fevers, sore throat and difficulty feeding. His mum is concerned he has developed some pain, drooling and difficulty swallowing. They’re going on holiday in 2 days, and she wants you to prescribe antibiotics. What do you do?
Admit to hospital
- difficulty feeding/swallowing
- drooling
BAD
What is used to assess someone’s severity when admitted with pneumonia?
CURB 65
Confusion (Y/N) Urea >7 Resp rate BP over 65
What pathogen is most associated with pneumonia and rash?
Mycoplasma (because abnormal clotting)
73 year old retired miner presents with cough, disorientation, chest pain. Temp 38.5, BP 105/55, RR 25/min CRP 280, WCC 14. 7, D-Dimer +ve Na 137, K 3.4, Urea 5.3, Creat 74 What’s his Mortality at 30 days?
1/4
What is normally the class of pathogen for upper respiratory infection?
Usually Viral (i.e. Rhinovirus, coronavirus, Respiratory Syncytial Virus/RSV, Parainfluenza & Influenza)
What is the border dividing upper from lower resp infections?
Above larynx
What secondary infections can occur from URT infections?
Secondary infections (H.influenza/Streptococcus) leading to Sinusitis, Otitis Media, Bronchitis or Pneumonia
What can the common cold lead to?
Can lead to otitis media, bronchitis, pneumonia
Why is pharyngitis so dangerous?
Airways can become swollen and completely close e.g. from quinsy- pus at back of throats- swelling can choke you and may need surgery
What pathogens can cause pharyngitis?
Viral, Group A B-haemolytic Strep, Mycoplasma
What are symptoms of pharyngitis?
Fever, Sore throat, Erythema of Pharynx
What are complications of pharyngitis?
Complications Glandular Fever Tonsillitis Quinsy (pus infection) Streptococcal infections Glomerulonephtitis Rheumatic Fever
can cause systemic infection
Describe glandular fever
Epstein Barr virus
Monospot test will be +ve
Rash with amoxicillin
aka infectious mononucleosis
Describe Croup
Acute Larygotracheobronchitis Cause: RSV
Barking Cough
Treatment
Usually self limiting
If admission required oral/nebulised steroids
common in babies
What is dysphonia?
Difficulty talking
What are features of epiglottitis?
Inflammation of Vocal Cords Drooling Dysphonia Dysphagia Drawn facies dical emergency Limited examination
Medical emergency - Secure airway
IV cefuroxime
Describe features of a LRTI
Below the Larynx
Usually considered sterile environment in healthy individuals
Likely pathogen is determined by route of transmission, co-morbidities, travel history, pre-disposing factors.
Treatment can be tailored due to severity, likely pathogen and history.
What is the definition of pneumonia?
Inflammation and consolidation of the lung tissue due to an infectious agent
Clinical:
Acute LRTI, fever, symptoms, signs in chest and abnormal CXR
Name signs and symptoms of pneumonia
Symptoms:
- Fever (chills)
- Cough (sputum)
- Pain
- Dyspnoea
- Coryza/pharyngitis (URTI)
- Vomiting
- Headache/myalgia
- General malaise
SIGNS
temperature (high or low)
Confusion
Tachypnoea
- Percussion
- Crackles
- Bronchial breathing
- Tactile Vocal Fremitus
What are risk factors for RTIs?
Host Factors Immunocompromise (HIV, immuodeficiency)
Alcohol misuse
Co-morbidities (Diabetes, Respiratory Disease)
Smoking
Physical Factors Tracheostomy/Laryngectomy Aspiration Risk – Stroke/Neuromuscular Disease
Drugs
MST and atropine (low mucociliary escalator)
Sedatives e.g. alcohol (low cough, epiglottic function) Steroids/Salicylates (low phagocytosis
What makes you three times more likely to get pneumonia?
Being over 65
Where does legionella come from?
Mediterranean
Where does pseudomonas come from?
SE asia, northern australia
What initial investigations are conducted with RTIs?
Routine Bloods
Blood Culture
Sputum Culture (AFB & MCS) Urine Pneumococcocal/Legionella (& Urine Output)
Specific tests – mycoplasma etc
CXR/ECG
CT Thorax/Thoracic Ultrasound (in specific cases)
How do you differentiate between pleural effusion and pneumonia on an x-ray?
Pleural effusion will have the curved meniscus sign on an xray
What are signals for mycoplasma (atypical)?
Extrapulmonary Symptoms e.g. Erythema Nodosum or Skin Rashes 25%
Neurological Signs in 5% (i.e. Meningo-encephalitis, Cerebellar Ataxia, Peripheral Neuropathy)
Can develop Arthralgia, Splenomegally, Hepatitis, Haemolytic Anaemia
Children/Young Adults
What are signals for legionella pneumonia (atypical)?
Hotel Stay in Last 14 days Delirium, Diarrhoea, Abdominal Pain, Derranged LFTs
Contaminated Water Humification Systems/Storage Tanks/Heating
Does not spread from person-to-person
Rapid urinary antigen testing available
What are signals for Staph aureus (atypical)?
Cavitating/Necrotising Pneumonia
Flu-like illness initially Severe, high mortality
?Blood-bourne spread i.e. IV Drug Use, Central Lines, Dialysis Lines
?Bacterial Endocarditis
What is treatment for pneumonia in uncomplicated situations?
Amoxycillin and clarithromycin or cephalosporin
What is treatment for pneumonia in complicated situations?
i.v cefuroxime + p.o clarithromycin
Or i.v. augmentin + p.o clarithromycin
What ABs are used in atypical infections?
Clarithromycin
rifampicin
tetracycline
What ABs are used when cavitation occurs?
Cerfuroxime
Metronidazole
Flucloxacillin
What pathogens cause cavitation?
clebsiella, e coli and stpah cause holes
What ABs are used if aspiration occurs?
Cerfuroxime
Metronidazole
What are complications of pneumonia?
Empyema ARDS Abscess Bronchiectasis (long term scarring) Pulmonary emboli
What are risk factors for lung abscess?
Bacterial load
Reduced cough
What are treatments for lung abscess?
IV ABs
Drainage
Surgery
DR DEAC PIMP: TB
Definition
Infection by M. tuberculosis or M. bovis
Risk Factors Low BMI HIV Alcohol Travel Immunosuppressed Genetic component? Crowded living conditions Vegetarianism Elderly / young Lung damage (silicosis etc) Diabetes Renal failure Smoking (20+ => 2-3x risk)
Differential diagnosis Pneumonia Noicardiosis Upper zone fibrosis: Sarcoidosis Lung cancer Extrinsic allergic alveolitis Single unilateral infiltrate Sarcoidosis Carcinoma Bilateral infiltrates Sarcoidosis Hilar lymphadenopathy Sarcoidosis Lymphadenopathy (other cause) Multiple cavities Pneumonia (cf timing) Wegener's granulomatosis PMF (progrssive massive fibrosis) Single cavities Abscess Carcinoma Rheumatoid Legionella Anthrax Mesothelioma (aspestos cancer)
Epidemiology 1/3 of world infected African/asian/indian/eastern europe 2-3 million die per year 1 new infection per second >40/100,000 = 'Endemic' 15 - 23% of AIDS deaths are from TB On the rise 99% of infections don't show (many) symptoms and => latent 10% of latent infections will reactivate later
Aetiology
Droplets in air spread mycobacteria
Usually infects lungs initially
Immune response to bacteria causes damage
Clinical features Upper zone fibrosis Bacteria prefer high up (more oxygen) Night sweats Productive cough Fever and Weight loss Anorexia Pleural effusion Finger clubbing Rales Pneumonia
Pathophysiology Type IV hypersensitivity Bacteria enveloped by macrophages Waxy cell wall => resistant to breakdown MCHII presentation, T cell activation Primary focus (Gohn focus) Secondary foci in lymph nodes => Il1, IL12, TNFa release => PMN infiltration Macrophages turn into Epitheliod cells Which fuse to form Langhans cells Fibroblasts infiltrate and lay down fibrin => caseating granulomas
Investigations Hx Mantoux Positive result is: >5mm HIV >10mm high-riskers >15mm everyone else NB false positives Steroids Immunosuppression Milliary TB? Quantiferon-TB Gold => IFN-g levels CXR Nodules Cavities Little scars Hilar caseous lymph nodes Upper lobe Sputum 3 different samples ZN stains Bacteria in sputum (direct visualisation) => infective Bacteria can be cultured => latent? Takes 3 weeks
Management NB DOTS treatment Directly observed treatment, short duration Isoniazid 6 months Blocks mycolic acid synthesis Peripheral neuropathy Prevent with vitamin B6 injections Rifampicin 6 months Inhibits DNA polymerase Stains body fluids pink Ethambutol 2 months Blocks arabinosyl transferase => blocks cell wall production Colour vision - Pyrazinamide First 2 months only Blocks fatty acid synthesis? Or disrupts membrane potential? Joint pain Pyridoxine 2 months Reduces ioniazid side-effects
Prognosis Untreated active disease kills 50% Miliary TB almost 100% fatal Treatment very effective if followed Secondary TB Peyers patches Mesentary Spine (Pott's spine) Liver Miliary TB (blood-born foci) Scrofula of neck (lymphatic spread
What is the definition of TB?
Infection by mycobacterium tuberculosis complex
What is the aetiology of TB?
Inhalation of
M. tuberculosis
M. africanum
M. bovis
Who are the risk groups for TB?
- Immigrants (56% of notifications in 2008)
- HIV (3% of tuberculosis also co-infected)
- Cancer
- Drug abusers
- Elderly
- Homeless ( x150 rate of national average) •Healthcare workers
What is the sex ratio for getting TB?
male to female 1:1
What parts of the world has the highest rates of TB?
India
Indonesia
South Africa
Brazil
What is the presentation of TB?
Pulmonary symtoms
- Cough (80%)
- Chest pain
- Fever/night sweats
- Weight loss
- Haemoptysis
Non-pulmonary
- lymphadenopathy
- Fatigue
- GI
- CVS
- CNS
- Bones
- GU tract
Primary infection (Ghon complex)
Secondary infection (lungs/other)
Reactivation (0-3%)
What are the investigations for TB?
AFB (acid fast bacilli) Culture Bactec PCR CXR
UBEX U Blood: Gamma interferon (FBC, ESR, CRP) ECG X-ray
Heaf/Mantoux
PCR (except blood)
Histology
How does the interferon gamma release assay work for TB?
Whole blood exposed to antigen specific to TB (ESAT6 and CFP 10)
- Measures the amount of interferon-γ released
- Not affected by prior BCG vaccination or other mycobacteria
-Highly sensitive for the diagnosis of latent disease
–QuantiFERON TB Gold 80-90%
–Elispot TSPOT TB test): >95%: favoured in I mmunosuppressed
How does primary TB normally appear on a CXR?
Primary TB usually appears as a central apical portion with a left lower-lobe infiltrate or pleural effusion
consolidation of the upper zone with ipsilateral hilar enlargement due to lymphadenopathy
What is the treatment for a pt infected with TB but has no disease?
chemoprophylaxis
What is the treatment for a pt with overt disease (TB)?
Quadruple therapy
What is the quadruple therapy for TB?
Rifampicin Isoniazid Pyrazinamide Ethambutol For at least 2 months
after 2 months, if cultures are fully sensitive, ethambutol and pyrazinamide may be stopped
What are common side effects of rifampicin?
Orange body secretions, hepatitis,
flu-like syndrome, thrombocytopaenia
What are common side effects of Isoniazid?
Peripheral neuropathy, hepatitis,
seizures,
psychoses
What are common side effects of Pyrazinamide?
Hyperuricaemia
Hepatitis
Rash
Gout
What are common side effects of Ethambutol?
Optic neuritis
Rashes
What is the criteria for close contacts in TB?
•Close contacts
> 8 hrs total in same room disease occurs in about 1% close contacts
10% total TB notifications
What are causes of TB drug resistance?
–Over the counter availability of drugs –Inappropriate treatment regimens –Inferior pharmaceutical preparations –Erratic drug supplies –Poor concordance
HIV and TB
- TB is commonest cause of death in HIV
- Difficulties in diagnosis •Serious adverse drug reactions
- Perceptions of the disease •Shear size of problem /overburdened health care systems
- Only infection that affects HIV -ve contacts
A 20 y/o man who is otherwise fit and well presents with a 3 day history of shortness of breath, fever and a productive cough. He mentions that his girlfriend had similar symptoms but has now recovered. He has rusty sputum and on examination there are bronchial breath sounds present and crackles. What is the most likely causative organism?
Streptococcus Pneumonia- rusty sputum
A 67 y/o man with COPD and with a 48 units / week history of alcohol consumption presents with symptoms consistent with pneumonia. He mentions coughing up currant jelly sputum. Which of the following is the most likely causative organism?
Klebsiella
Currant jelly sputum
Alcoholics
COPD
Pneumonia features of Pseudomonas
green, cystic fibrosis
Pneumonia features of Legionella
Legionella - water tanks, deranged LFTs
Pneumonia features of Chlamydia psittaci
Parrots
Pneumonia features of Staphylococcus
upper lobe cavitation, IV drugs
A newborn baby has hyaline membrane disease and is treated with exogenous surfactant. This condition is associated with dysfunction in which of the following cell types?
Type 2 pneumocytes make surfactant
Hyaline membrane disease - disorder of Type 2 cells
Can be given steroids prior to delivery
Type 1 cells provide the large surface area
