Respiratory Flashcards
How do you grade dyspnoea
- MRC Dyspnoea Scale
- Grade 1 – Breathless on strenuous exercise
- Grade 2 – Breathless on walking up hill
- Grade 3 – Breathless that slows walking on the flat
- Grade 4 – Stop to catch their breath after walking 100 meters on the flat
- Grade 5 – Unable to leave the house due to breathlessness
spirometry findings in COPD
- FEV1 /FVC ratio is <0.7
how is severity of airflow obstruction graded
- Stage 1: FEV1 >80% of predicted
- Stage 2: FEV1 50-79% of predicted
- Stage 3: FEV1 30-49% of predicted
- Stage 4: <30% of predicted
COPD investigations
- CXR
- To exclude other pathology like lung cancer
- FBC
- For polycythaemia which is a response to chronic hypoxia
- BMI
- As a baseline to assess weight loss (cancer or severe COPD) or weight gain (due to steroid therapy)
- Sputum culture
- To assess for chronic infections like pseudomonas
- Serum alpha-1 antitrypsin
- Alpha-1 antitrypsin deficiency leads to early onset and more severe COPD
- Transfer factor for carbon monoxide
- TLCO is decreased in COPD and can give an indication of severity of disease
Long term COPD management
- Smoking cessation
- Annual pneumococcal and flu vaccines
- Pulmonary rehab
- Stage 1
- SABA (e.g. salbutamol) or SAMA (e.g. ipratropium) to use as needed
- Stage 2
- LABA (e.g. formoterol, salmeterol) plus LAMA (e.g. tiotropium)
- Stage 3
- LABA plus LAMA plus ICS
- If no improvement in 3 months then switch back to LABA plus LAMA
management of acute exacerbation of COPD
- Nebulised bronchodilators (salbutamol and ipratropium)
- Steroids (hydrocortisone or oral prednisolone)
- Antibiotics if evidence of infection
- Physiotherapy
- If not responding to first line treatment
- IV aminophylline
- Non-invasive ventilation
- Intubation and ventilation with admission to intensive care
- Doxapram
investigation of asthma in the community
fractional exhaled nitric oxide
spirometry with bronchodilator reversibility
how would you define good asthma control
No daytime symptoms.
No night-time waking due to asthma.
No need for rescue medication.
No asthma attacks.
No limitations on activity including exercise.
Normal lung function (FEV1 and/or PEF > 80% predicted or best).
Minimal side-effects from medication.
additional management of asthma in the community
yearly asthma review
emergency plan
yearly flu jab
describe asthma treatment ladder in adults
- everyone gets a SABA
- SABA + low dose ICS (beclametasone)
- SABA + low dose ICS + LTRA (montelukast)
- SABA + low dose ICS + LABA (salmeterol) +/- LTRA (depending on response to LTRA)
- MART (maintenance and reliever therapy) +/- LTRA
- MART includes fast acting LABA and low dose ICS
- used as daily maintenance and as a reliever
- Switch to a MART with moderate dose ICS +/- LTRA
- consider additional drug such as theophylline or switching to high dose ICS
asthma treatment ladder in children
- SABA
- SABA + low dose ICS (beclametasone)
- SABA + low dose ICS + LTRA (montelukast)
- SABA + low dose ICS + LABA (salmetarol)
- SABA + MART (low dose ICS in the MART)
- SABA + moderate dose ICS + LABA (either as MART or fixed dose regimen)
- here you can either increase to high dose ICS or trial new drug such as theophylline
how can you establish whether someone’s asthma is well controlled
- answering no to all three of the RCP Three Questions is consistent with well controlled asthma
- are you having trouble sleeping because of your asthma symptoms?
- have you recently had your asthma symptoms during the day?
- has your asthma interfered with your normal activities?
how do you grade asthma attacks
- Mild: PEFR >75%
- Moderate: PEFR <75%
- Severe:
- PEFR <50%
- can’t complete sentences
- RR >25
- PR >110
- Life threatening (33 92 CHEST)
- 33: PEFR <33%
- 92: Sats <92%
- Cyanosis
- Hypotension
- Exhaustion
- Silent chest
- Tachycardia
management for moderate asthma attack
Nebulised beta-2 agonists (i.e. salbutamol 5mg repeated as often as required)
Nebulised ipratropium bromide
Steroids. Oral prednisolone or IV hydrocortisone. These are continued for 5 days
Antibiotics if there is convincing evidence of bacterial infection
management of severe asthma attack
management of life threatening asthma attack
IV magnesium sulphate infusion
admission to HDU/ICU
Intubation - however this should happen early as it’s very difficult to intubate in bronchospasm
ABGs in an asthma attack
Initially patients will have a respiratory alkalosis as tachypnoea causes a drop in CO2.
A normal pCO2 or hypoxia is a concerning sign as it means they are tiring and indicates life threatening asthma.
A respiratory acidosis due to high CO2 is a very bad sign in asthma.
what are the different types of lung cancer and how common are they
list sub-types in order of prevalence
- Non small cell lung cancer (80%)
- adenocarcenoma
- squamous cell carcinoma
- large cell carcinoma
- other
- small cell lung cancer (20%)
*
signs and symptoms of lung cancer
finger clubbing
coughing
haemoptysis
lymphadenopathy
recurrent pneumonia
weightloss
cough
investigations of lung cancer
- chest x ray
- contrast enhanced CT
- bronchoscopy
- biopsy (by bronchoscopy or percutaneously) and histological diagnosis
is prognosis generally better for small cell lung cancer or non-small cell lung cancer
non-small cell lung cancer generally has a better prognosis
treatment options for lung cancer
- surgery
- lobectomy
- segmentectomy
- wedge resection
- radiotherapy
- chemotherapy
- curative
- palliative
- treatment for small cell lung cancer
- outcomes usually worse so normally just radiotherapy and chemo
- palliative
- endobronchial treatment with stents and debulking works for palliative treatment of obstruction caused by cancer
list 9 extra pulmonary manifestations of lung cancer
what is recurrent laryngeal nerve palsy
presents as hoarse voice and is caused by lung cancer pressing on the recurrent laryngeal nerve
what is phrenic nerve palsy
due to compression of the phrenic nerve and results in diaphragm weakness - presents as shortness of breath
what happens with superior vena cava obstruction
- it is a complication of lung cancer and is caused by direct compression of the tumour on the superior vena cava
- it presents with
- facial swelling
- difficulty breathing
- distended veins in the neck and upper chest
- pemberton’s sign is where raising the hands over the head causes facial congestion and cyanosis - this is a medical emergency
what is horner’s syndrome
triad of partial ptosis, anhidrosis and miosis
why might a lung cancer cause a horner’s syndrome
it is caused by a pancoast tumour (tumout of the pulmonary apex) pressing on the sympathetic ganglion
why might lung cancer cause SIADH and how does it present
ectopic ADH secretion by a small cell lung cancer and presents with hyponatraemia
why might lung cancer cause cushing’s syndrome
ectopic ACTH secretion by a small cell lung cancer
why might lung cancer cause hypercalcaemia
ectopic parathyroid hormone secretion from a squamous cell carcinoma
what is limbic encephalitis and how is it caused
- small cell lung cancer causes immune system to make antibodies to tissue in the brain - specifically the limbic system
- this causes
- hallucinations
- confusion
- seizures
- memory impairment
- associated with anti-Hu antibodies
what is lambert-eaton myasthenic syndrome and why do you get the specific symptoms
- immune system produces antibodies against the small cell lung cancer
- these cross-react with voltage gated calcium channels sited on presynaptic terminals in motor neurons
- it mainly affects
- proximal muscles
- intraocular muscles
- diplopia
- levator muscles
- ptosis
- pharyngeal muscles
- slurred speach and dysphagia
- also causes autonomic dysfunction
- dry mouth
- blurred vision
- impotence
- dizziness
cxr findings in lung cancer
hilar enlargement
consolidation
lung collapse
pleural effusion
bony secondaries
rare causes of PE (i.e. not clot in legs)
- right ventricular thrombosis (post MI)
- septic emboli (right sided endocarditis)
- fat embolus
- air embolus
- amniotic fluid embolus
- neoplastic cells
- parasites
what is the risk score for PE
wells criteria for PE
what are the wells criteria for PE
- clinical signs and symptoms of DVT
- PE is #1 diagnosis or equally likely
- heart rate >100
- immobilisation in the last 3 dats or surgery in the previous 4 weeks
- previous, objectively diagnosed PE or DVT
- hemoptysis
- malignancy with treatment in the last 6 months or palliative
risk factors for PE
immobility
recent surgery
long haul flights
pregnancy
hormone therapy with oestrogen
malignancy
polycythaemia
systemic lupus erythematosus
thrombophilia
signs of PE
pyrexia
cyanosis
tachypnoea
tachycardia
hypotension
raised JVP
pleural rub
pleural effusion
thromboprophylaxis of patients admitted to hospital
low molecular weight heparin such as enoxaparin
investigations of PE based on wells score
likely: perform a CTPA
unlikely: d-dimer and if positive perform a CTPA
diagnosis of PE
- CTPA
- this is first choice
- IV contrast highlights pulmonaty arteries to demonstrate blood clots
- VQ scan
- used in patients with
- renal impairment
- contrast allergy
- risk from radiation
- area of embolism will be ventilated but not perfused
- used in patients with
- CXR may be normal
cxr findings in PE
- may be normal
- oligaemia of affected segment
- dilated pulmonary artery
- linear atelectasis
- small pleural effusion
- wedge-shaped opacities
ecg findings in PE
- may be normal
- tachycardia
- RBBB
- right ventricular strain
initial management of PE
- apixaban or rivaroxaban started immediately before confirming diagnosis
- where there is massive PE and they are haemodynamically unstable
- thrombolysis
- inject fibrinolytic medication such as
- alteplase
- streptokinase
- tenecteplase
- either IV or catheter directed thrombolysis directly into pulmonary arteries
- this is risky
- inject fibrinolytic medication such as
- thrombolysis
long term anticoagulation following PE
- options are
- warfarin
- target INR 2-3
- a noac
- apixaban
- rivaroxaban
- dabigatran
- LMWH
- first line treatment in pregnancy or cancer
- warfarin
- continue anticoagulation for
- 3 months if obvious reversible cause
- beyond 3 months if cause unclear, if recurrent VTE or an irreversible underlying cause such as thrombophilia
- 6 months in active cancer
- then review
describe the bacteria that causes TB
mycobacterium tuberculosis
acid fast bacilli
what staining technique is used for TB
zeihl neelsen stain
this turns TB bright red against a blue background
disease course of TB
- active TB is where there is active infection in various areas within the body
- small granulomas (tubercles) form around the infection when host macrophages engulf the organism
- in 80% of cases these tubercles heal spontaneously
- in 20% of cases you get latent TB
- this is where the infection is encapsulated but not eliminated
- individual is otherwise healthy
- if latent TB reactivates it is known as secondary TB
- this is usually precipitated by impaired immune function
- miliary TB occurs when primary infection is not adequately contained and invades the bloodstream
- results in severe disseminated disease
TB presentation
- 70% is pulmonary TB
- lethargy
- fever
- night sweats
- cough with or without haemoptysis
- lymphadenopathy
- erythema nodosum
- spinal pain in spinal TB
- this is AKA pott’s disease of the spine
investigating TB
- difficult because bacteria grow slowly
- two tests for immune response to TB
- mantoux
- interferon-gamma release assay
- if active disease is suspected
- X ray
- sputum cultures
CXR findings in TB
- pulmonary TB is unlikely with a normal CXR
- primary TB
- central apical portion with lower lobe infiltrate or pleural effusion
- cavitation
- reactivated TB
- no pleural effusion and lesions are apical in position
- cavitation
- severe disease with poor immune response can produce a picture like millet seeds over the CXR
- uniform 1-10mm shadows
obtaining samples for suspected pulmonary TB
- need at least three sputum samples for culture and microscopy
- including one early morning sample
- if spontaneous not possible consider bronchoscopy and lavage
- or in children gastric washing
- start treatment without culture results if clinical signs and symptoms of TB
- complete treatment even if culture results are negative
obtaining samples for suspected non-respiratory TB
- needle aspiration
- lymph node biopsies
- early morning urine
- start treatment if histology and clinical picture are consistent with TB before culture results are available
- continue treatment even if results are negative
- CXR should be done for co-existing respiratory TB in all patients with non-resp TB
how are TB samples analysed
staining with Ziehl-Neelsen stain
rapid direct microscopy for acid fast bacilli
they appear red on a blue background
culture on a lowenstein-jensen slope which takes 4-8 weeks due to slow bacterial growth
sensitivity cultures then take a further 3-4 weeks
contact screening in TB
mantoux testing to diagnose LTBI in people who are household contacts or close contaccts of all patients with TB
mantoux may well be positive in those with the BCG so offer interferon gamma as first line in these people
if positive refer to TB specialist
public health stuff following diagnosis of TB
- all cases must be notified under the public health regulations 1988
- admit to negative pressure single side-room vented to the outside until they are proven to be non-infectious
drug treatment of active TB without CNS involvement
- start all at the same time
- isoniazid for 6 months
- rifampicin for 6 months
- pyrazinamide for two months
- ethambutol for two months
drug treatment of active TB of the CNS
side effects of rifampicin
- red orange discolouration of urine and tears
- cytochrome P450 inducer –> OCP
- during first two months of rifampicin transient derangement of LFTs is common and generally doesn’t require change of treatment
side effects of isoniazid
peripheral neuropathy
prescribe pyridoxine (B6)
side effects of pyrazinamide
hyperuricaemia which may result in gout
side effects of ethambutol
can reduce visual acuity and cause colour blindness
which people should be treated for latent TB (LTBI)
- people mantoux positive without prior BCG
- people mantoux positive and interferon-gamma positive is prior BCG
- people with TB scars on CXR without history of prior treatment
- people with HIV who are close contacts of those with sputum-smear-positive respiratory TB
drug treatment of LTBI
- either if no HIV
- 6 months of isoniazid or
- 3 months of isoniazid and rifampicin
- any LTBI with HIV
- 6 months of isoniazid
what are bronchial breath sounds
harsh breath sounds equally loud on inspiration and expiration
caused by consolidation of the lung tissue around the airway
how do you assess severity of pneumonia
- in hospital
- CURB65
- Confusion
- Urea >7
- Resp rate >30
- Blood pressure <90 systolic or <60 diastolic
- 65 Age >65
- in comunty
- CRB65
- no urea testing
- if CRB score of anything other than 0 consider referring to hospital
CAP treatment in adults
- CRB65 of 0 (low severity)
- amoxicillin 500mg 3 times per day for 5 days
- if penicillin allergy then
- doxycycline 200mg on first day then 100mg once a day for 4 days
- CRB65 of 1/2 (moderate severity)
- amoxicillin 500mg 3 times a day for 5 days AND
- clarithromycin 500mg twice a day for 5 days
CURB 65 interpretation
score 0/1: consider treatment at home
score 2 or more: consider admission
score 3 or more: consider intensive care assessment
most common atypical pneumonias
M. pneumoniae
C. pneumoniae
Legionella pneumophila
what is the definition of hap
hospital acquired pneumonia
new infection of lung parenchyma appearing more than 48hrs after admission to hospital
HAP occuring less than 5 days after hospital admission is normally caused by
S.pneumoniae
HAPs occuring more than 5 days after hospital admission are normally caused by
H.influenzae
MRSA
pseudomonas aeruginosa
legionella pneumophila presentation
typically caused by infected water supplies or air conditioning units. It can cause hyponatraemia (low sodium) by causing an SIADH.
treatment for atypical pneumonias
Macrolides such as clarithromycin
Quinolones such as levofloxacin
Tetracyclines such as doxycycline
mycoplasma pneumoniae presentation
causes a milder pneumonia and can cause a rash called erythema multiforme characterised by varying sized “target lesions” formed by pink rings with pale centres. It can also cause neurological symptoms in young patient in the exams.