Acute Resp Flashcards
What is T1RF
Hypoxia
What is T2RF
Hypoxia
Hypercapnic
What is the fundamental problem with T1RF?
V/Q mismatch
Why is CO2 not raised in T1RF
Because we hyperventilate to compensate
What is the fundamental problem in T2RF
Alveolar hypoventilation
Acute causes of T1RF (7)
Acute asthma Atalectasis Pulmonary Oedema Pneumonia Pneumothorax PE ARDS
Acute causes of T2RF (6)
Acute severe asthma COPD Upper airway obstruction Neuropathies (GBS, MND) Drugs (opiates)
Traumatic vs spontaneous pneumathoraces - which pleura is involved
Traumatic - at least the parietal
Spontaneous - at least the visceral
Mx of a tension pneumothorax
Immediate needle decompression with a large bore cannula in the MCL in the 2nd ICS
Mx of a spontaneous pneumothorax (primary and secondary)
PRIMARY
If no SoB or <2cm: discharge
>2cm/SoB: needle aspiration + O2
Otherwise: chest drain
SECONDARY
If no SoB or <1cm: Observe + O2
1-2cm: needle aspiration
>2cm/SoB: chest drain
What scoring is used to investigate a PE
Well’s
How is Well’s score used
> 4 CTPA
=<4 D-dimer
What sign on a CXR shows a PE
Westermark
What is occluded in chronic PE and what is the symptom
Pulmonary microvasculature
Exertional dyspnoea
What do we use to prevent VTE in hospital
TEDs and Tinz
Thrombo-embolic deterrent stockings and Tinzaparin (a popular LMWH)
What does the name of thrombolytic drugs end in?
-ase
3 thrombolytics commonly used
Alteplase
Streptokinase
rt-PA
Mx of a PE
Are they haemodynamically stable? Yes - subacute/chronic Respiratory support Anticoagulation e.g. Fondaparinux/Heparin for 5 days Warfarin for 3 months
No - massive PE Respiratory support 1st line: Thrombolysis 2nd line: Embolectomy e.g. Alteplase Streptokinase rt-PA
Causes of ARDS (7)
Drugs Barotrauma Nearly drowning Severe burns Sepsis Pneumonia Transfusion reactions
In which population is ARDS particularly common in and why(2)
critically ill/ITU patients
because many of the causes of ARDS such as burns need intensive management – but also because mechanical over-ventilation can trigger ARDS
What type of respiratory failure is caused by ARDS
T1
Pathophysiology of ARDS
Complicated inflammatory response which leads to diffuse alveolar damage. As inflammatory markers are recruited they increase the vascular permeability in order to promote further recruitment. This leads to fluid entering the lungs in a similar way to pulmonary oedema. This then causes your alveoli to collapse collapse which decreases the surface area for gas exchange and also increases the distance between the capillary and the alveoli (diffusion distance). This decreases the rate at which oxygen can be loaded into the capillary – decreasing oxygenation (type 1 resp failure)
X ray findings for pulmonary oedema
A - alveolaroedema(bat wing opacities) B - Kerley B lines. C - cardiomegaly. D - dilated upper lobe vessels. E - pleural effusion.
X ray findings for ARDS
A - alveolaroedema(bat wing opacities) B - Kerley B lines. C - cardiomegaly. D - dilated upper lobe vessels. E - pleural effusion.
