Breathlessness Flashcards
what should be administered to critically unwell patients
high flow oxygen
- hypoxia leds to end organ damage
when should oxygen be used
when the patient is hypoxic
- oxygen should be titrated to maintain saturations within the desired range
your first priority is to treat….
hypoxia
what is appropriate to deliver high flow oxygen in critically unwell patients
- reservoir bag and mask it initially designed to deliver high flow oxygen in critically unwell patients
why is high flow nasal oxygen not used during the COVID-19 pandemic
- its use may contaminate the environment with virus particles and place excessive strain on oxygen supplies
what are the prescribing guidelines in the COVID-19 pandemics
92-96% in first instance from the current range of 94-98%
Name the types of oxygen delivery devices
- high flow oxygen with reservoir bag and mask
- humidified oxygen
- venturi masks
- nasal cannulae
- simple face masks
when should high flow oxygen with reservoir bag and mask used
for initial management of critically unwell patients requiring high flow oxygen
when is humidified oxygen used
for patients requiring high flow oxygen for longer periods of time or for those who experience discomfort from upper airway dryness
When are venturi masks used
for delivery of specific oxygen concentration
When are nasal cannuale masks used
can be substituted for face masks in patients requiring low flow oxygen. Delivery of oxygen to maintain saturations within the desired range will achieve adequate oxygenation
when are simple face masks used
should be avoided to deliver low flow oxygen (below 5 l/min) as they may cause carbon dioxide rebreathing and increased resistance to inspiration.
How is the physiological change of breathlessness detected
- Peripheral and central chemoreceptors (hypoxia, hypercapnia, acidosis)
- Pulmonary stretch receptors
- Vascular stretch receptors (pulmonary vascular distension)
- Airway mucosal sensation (temperature, irritant substances)
- Facial skin cooling.
How do patients often describe breathlessness as
- uncomfortable sensation of work or effort
- tightness
- air hunger/unsatisfied inspiration
what can hyperventilation cause
- hypocapnia
- respiratory alkalosis
what does hyperventilation occur with
- anxiety
What are strong risk factors for a PE
- fracture
- hip or knee replacement
- major general surgery
- major trauma
- spinal cord injury
What are moderate risk factors for a PE
- arthroscopic knee surgery
- central venous lines
- chemotherapy
- cognitive heart or respiratory failure
- hormone replacement therapy
- malignancy
- oral contraceptive therapy
- paralytic stroke
- pregnancy
- thrombophilia
What are weak risk factors
- bed rest over three days
- immobility due to sitting
- increasing age
- laparoscopic surgery
- obesity
- pregnancy
- varicose veins
How would you distinguish between a PE and pneumothorax
Chest X ray
What chest X ray is recommended for the diagnosis of a pneumothorax
erect inspiratory chest X ray
what is the gold standard test used to estimate the size of a pneumothorax
- a chest CT without contrast is the gold standard to estimate a size of a pneumothorax
- helpful to detect small pneumothoraces
What does NICE advice if a patient presents with symptoms or signs of a PE
- should request a chest X ray to exclude other causes for their signs and symptoms such as pneumothorax or consolidation
what score do you use to calculate if the PE is likely
Wells score
What are the clinical features of the wells score
- Clinical signs and symptoms of DVT = 3
- An alternative diagnosis is less likely than PE = 3
- heart rate is greater than 100 beats per minute = 1.5
- immobilisation for more than 3 days or surgery in the previous 4 weeks = 1.5
- Previous DVT/PE = 1.5
- haemoptysis = 1
- malignancy = 1
- PE is likely if more than 4 points
what do you do if the wells score is greater than 4 indicating a PE
- arrange a CT pulmonary angiogram or V/Q SPECT scan to confirm diagnosis
how is a pulmonary thrombus diagnosed by
- Presence of blood clot (lower density than contrast)
- Absence of contrast in pulmonary vascular tree beyond the clot.
Might also be signs of right heart strain - this signifies submissive or massive PE
- size of right ventricle and bulging of IV septum
- pulmonary artery diameter larger than aorta
How do you treat a PE
- anticoagulation - continue for a minimum of 3 months
- apixaban and rivaroxaban without lead in
- offer treatment with LMWH for at least 5 days followed by dabigatran or edoxaban or LMWH concurrently with a vitamin K antagonist for at least 5 days or until the INR is at least 2 in 2 consecutive readings
who should long term anticoagulation be considered for in
- unprovoked PE
- PE with ongoing risk factors as long as the recurrence outweighs the risk of bleeding
What are the signs of tension pneumothorax
- Unilateral reduction in air entry
- Unilateral hyper-resonance to percussion
- Tracheal deviation
- Cardiorespiratory compromise (SpO2 85% on 15 L/min O2, BP 84/62 mmHg, tachycardia and prolonged capillary refill).
How should you treat a tension pneumothorax
- correct management is emergency decompression using a large bore cannula or if available a needle thoracostomy device
- chest drain should then be inserted following needle decompression
- needle should be left in place until chest drain is secured
where should the cannula be inserted in a pneumothorax
- should be inserted on the side of the pneumothorax
- 2nd intercostal space mid clavicular line
what is a primary pneumothorax
Primary spontaneous pneumothoraces occur in healthy patients without underlying lung disease.
What is a secondary pneumothorax
Secondary pneumothoraces occur in patients with pre-existing lung disease, such as chronic obstructive pulmonary disease (COPD)
what is associated with higher or lower mortality and morbidity
- secondary pneumothorax is associated with a higher mortality and morbidity than a primary spontaneous pneumothorax
what is the different in treatment for primary and secondary pneumothroaces
- recommends aspiration as the initial treatment for primary pneumothoraces which are larger than 2 cm,
- insertion of a chest drain as initial treatment for secondary pneumothoraces which are larger than 2 cm.
What does it mean if the drain is swinging and not bubbling in air
The drain is swinging, which informs you that the drain is in the pleural space and is not blocked. It is not bubbling, which tells you that it is not currently draining any air.
what do you do once the chest drain has finished drawing out the air
- important to reassess with a chest X ray to ensure that the lung has fully re-expanded before removing the drain
- a chest drain should not usually be removed before bubbling has ceased and chest x ray has confirmed expansion
What should a chest drain be inserted for spontaneous pneumothorax
- Following unsuccessful needle aspiration in a patient with primary spontaneous pneumothorax (which is performed if size of radiographic pneumothorax greater than 2 cm and/or when the patient is breathless)
- In secondary spontaneous pneumothorax where size is 1 to 2 cm, following unsuccessful needle aspiration
- In secondary spontaneous pneumothorax where size is greater than 2 cm, as a first procedure.
