Respiratory Flashcards
What is Maintenance and Reliever Therapy? (MART)
Maintenance and reliever therapy (MART)
- A form of combined ICS and LABA treatment in which a single inhaler, containing both ICS and a fast-acting LABA, is used for both daily maintenance therapy and the relief of symptoms as required
(example, formoterol)
What is the stepwise approach for management of asthma?
Newly diagnosed Asthma:
- Short-acting beta agonist (SABA)
Not controlled on previous step
OR
Newly-diagnosed asthma with symptoms >= 3 / week or night-time waking:
- SABA + low-dose inhaled corticosteroid (ICS)
- SABA + low-dose ICS + leukotriene receptor antagonist (LTRA)
- SABA + low-dose ICS + long-acting beta agonist (LABA)
Continue LTRA depending on patient’s response to LTRA - SABA +/- LTRA
Switch ICS/LABA for a maintenance and reliever therapy (MART), that includes a low-dose ICS - SABA +/- LTRA + medium-dose ICS MART
OR consider changing back to a fixed-dose of a moderate-dose ICS and a separate LABA
- SABA +/- LTRA + one of the following options:
- Increase ICS to high-dose (only as part of a fixed-dose regime, not as a MART)
- A trial of an additional drug (for example, a long-acting muscarinic receptor antagonist or theophylline)
- Seeking advice from a healthcare professional with expertise in asthma
What are the features of COPD?
COPD is an umbrella term encompassing the older terms chronic bronchitis and emphysema. In the vast majority of cases, COPD is caused by smoking. Some patients with more mild disease may just need to use a bronchodilator occasionally whereas other patients may have several hospital admissions a year secondary to infective exacerbations.
Features:
- Cough: often productive
- Dyspnoea
- Wheeze
- In severe cases, right-sided heart failure may develop resulting in peripheral oedema
What investigations are performed in suspected COPD?
The following investigations are recommended in patients with suspected COPD:
- Post-bronchodilator spirometry to demonstrate airflow obstruction: FEV1/FVC ratio less than 70%
Chest x-ray:
- hyperinflation
- bullae: if large, may sometimes mimic a pneumothorax
- flat hemidiaphragm
- also important to exclude lung cancer
What are some causes of white shadowing on chest x ray?
- Consolidation
- Pleural effusion
- Collapse
- Pneumonectomy
- Specific lesions e.g. tumours
- Fluid e.g. pulmonary oedema
What are the components of Sepsis Six?
The Sepsis Six consists of three diagnostic and three therapeutic steps – all to be delivered within one hour of the initial diagnosis of sepsis:
3 In:
- Titrate OXYGEN to a saturation target of 94%
- Administer empirical intravenous ANTIBIOTICS
- Start intravenous FLUID resuscitation
3 Out:
- Commence accurate URINE OUTPUT measurement.
- Take BLOOD CULTURES and consider source control
- Measure serial serum LACTATE
What are the components of CURB65 in assessing the severity of pneumonia?
C Confusion (abbreviated mental test score <= 8/10)
U urea > 7 mmol/L
R Respiration rate >= 30/min
B Blood pressure: systolic <= 90 mmHg and/or diastolic <= 60 mmHg
65 Aged >= 65 years
- consider home-based care for patients with a CURB65 score of 0 or 1 - low risk
- consider hospital-based care for patients with a CURB65 score of 2 or more - intermediate risk
- consider intensive care assessment for patients with a CURB65 score of 3 or more - high risk (more than 15% mortality risk)
What is the management for low severity community acquired pneumonia?
- Amoxicillin is first-line
- if penicillin allergic then use a macrolide or tetracycline
- NICE now recommend a 5 day course of antibiotics for patients with low severity community acquired pneumonia
What is the management of moderate and high-severity community acquired pneumonia?
- Dual antibiotic therapy is recommended with amoxicillin and a macrolide
- a 7-10 day course is recommended
- NICE recommend considering co-amoxiclav, ceftriaxone or piperacillin with tazobactam and a macrolide in high-severity community acquired pneumonia.
Organism causing acute exacerbation of COPD?
The most common bacterial organisms that cause infective exacerbations of COPD are:
- Haemophilus influenzae (most common cause)
- Streptococcus pneumoniae
- Moraxella catarrhalis
Respiratory viruses account for around 30% of exacerbations, with the human rhinovirus being the most important pathogen.
Management for acute exacerbations of COPD?
NICE guidelines from 2010 recommend the following:
- Increase frequency of bronchodilator use and consider giving via a nebuliser
- Give prednisolone 30 mg daily for 5 days
- It is common practice for all patients with an exacerbation of COPD to receive antibiotics. NICE do not support this approach. They recommend giving oral antibiotics ‘if sputum is purulent or there are clinical signs of pneumonia’
- The BNF recommends one of the following oral antibiotics first-line: amoxicillin or clarithromycin or doxycycline.
How is diagnosis of asthma made?
Diagnostic testing
Patients >= 17 years
- patients should be asked if their symptoms are better on days away from work/during holidays. If so, patients should be referred to a specialist as possible occupational asthma.
- All patients should have spirometry with a bronchodilator reversibility (BDR) test.
- All patients should have a FeNO test.
FeNO: Fractional exhaled Nitric Oxide. Levels of NO correlate with airway inflammation from eosinophils.
What are the objective tests used in diagnosing asthma?
Fractional exhaled Nitric Oxide (FeNO)
- in adults level of >= 40 parts per billion (ppb) is considered positive.
Spirometry
- FEV1/FVC ratio less than 70% is considered obstructive.
Reversibility testing
- in adults, a positive test is indicated by an improvement in FEV1 of 12% or more and increase in volume of 200 ml or more.
What is Light’s criteria?
Light’s criteria helps to distinguish between a transudate and an exudate.
- Exudates have a protein level of >30 g/L
- Transudates have a protein level of <30 g/L
if the protein level is between 25-35 g/L, Light’s criteria should be applied. An exudate is likely if at least one of the following criteria are met:
- pleural fluid protein divided by serum protein >0.5
- pleural fluid LDH divided by serum LDH >0.6
- pleural fluid LDH more than two-thirds the upper limits of normal serum LDH
Type 1 respiratory failure?
Type 1 respiratory failure: Low pO2, no CO2 retention
Type 2 respiratory failure?
Type 2 respiratory failure: Low pO2, high pCO2
(example: COPD)
Indications for chest drain insertion?
A chest drain is a tube inserted into the pleural cavity which creates a one-way valve, allowing movement of air or liquid out of the cavity.
Chest drain insertion is indicated in cases of:
- Pleural effusion
- Pneumothorax not suitable for conservative management or aspiration
- Empyema
- Haemothorax
- Haemopneumothorax
- Chylothorax
- In some cases of penetrating chest wall injury in ventilated patients
What are the borders of the safety triangle for safe insertion of a chest drain?
The triangle of safety actually has four sides involving:
- The base of the axilla (superior boundary)
- Lateral edge of the pectoralis major (medial boundary)
- 5th intercostal space (inferior boundary)
- Anterior border of latissimus dorsi (lateral boundary).
What is the management for primary and secondary pneumothorax?
A pneumothorax is termed primary if there is no underlying lung disease and secondary if there is.
Primary pneumothorax
Recommendations include:
- If the rim of air is < 2cm and the patient is not short of breath then discharge should be considered
- Otherwise, aspiration should be attempted
- If this fails (defined as > 2 cm or still short of breath) then a chest drain should be inserted
- Patients should be advised to avoid smoking to reduce the risk of further episodes - the lifetime risk of developing a pneumothorax in healthy smoking men is around 10% compared with around 0.1% in non-smoking men
Secondary pneumothorax
Recommendations include:
- If the patient is > 50 years old and the rim of air is > 2cm and/or the patient is short of breath then a chest drain should be inserted.
- Otherwise aspiration should be attempted if the rim of air is between 1-2cm. If aspiration fails (i.e. pneumothorax is still greater then 1cm) a chest drain should be inserted. All patients should be admitted for at least 24 hours
- if the pneumothorax is less the 1cm then the BTS guidelines suggest giving oxygen and admitting for 24 hours
- regarding scuba diving, the BTS guidelines state: ‘Diving should be permanently avoided unless the patient has undergone bilateral surgical pleurectomy and has normal lung function and chest CT scan postoperatively.’
Common causes of respiratory alkalosis?
Common causes:
- Anxiety leading to hyperventilation
- pulmonary embolism
- salicylate poisoning*
- CNS disorders: stroke, subarachnoid haemorrhage, encephalitis
- altitude
- pregnancy
*salicylate overdose leads to a mixed respiratory alkalosis and metabolic acidosis. Early stimulation of the respiratory centre leads to a respiratory alkalosis whilst later the direct acid effects of salicylates (combined with acute renal failure) may lead to an acidosis
