Acute Respiratory Distress Flashcards
(23 cards)
What is acute respiratory distress syndrome?
Acute respiratory distress syndrome (ARDS) is defined as acute lung damage within one week of trigger, leading to non-cardiogenic pulmonary oedema.
What is the pathophysiology of Acute respiratory distress?
It involves diffuse bilateral alveolar injury, with endothelial disruption and leakage of fluid INTO the alveoli from pulmonary capillaries. There will be reduced ventilation so a pulmonary shunt will occur.
Damage to type 1 alveolar cells causes dyspnea; damage to type 2 alveolar cells causes a decrease in surfactant production
What are the common causes to ARDS?
Lung injury from:
Sepsis
Pneumonia
Aspiration
Pancreatitis
Major trauma
Transfusion associated lung injury
What are the symptoms of ARDS?
Severe dyspnoea
Tachypnoea and use of accessory muscles
Confusion and pre syncope
What investigations should be performed for ARDS?
Viral swab
Sputum culture
ABG for hypoxia
Serum amylase to screen for pancreatitis
CXR
What are the criteria of ARDS?
Berlin Criteria for ARDS
Acute onset less than 1 week
Ratio of P/F less than 300
Diffuse bilateral infiltrates
Swangon catheter or echocardiogram to confirm non cardiogenic pulmonary oedema
What are the complications of acute respiratory distress syndrome?
Pulmonary hypertension
Ventilator associated pneumonia
Ventilator induced lung injury
How does mechanical ventilator exacerbate ARDS?
Risk of tension pneumothorax
Over distention of alveoli causes inflammation of lungs and resulting in alveolar oedema
Alveola derecruitment (alveolar collapse)
Hyperoxia which can act as a pulmonary vasodilator and cause a V/Q mismatch
What is the P/F ratio?
P/F ratio which is:
P= ratio of arterial oxygen
F= inspired oxygen from external sources
The lower the ratio, the worse the ARDS because they require more oxygen support
What is a Mild ARDs?
100-200 P/F ratio
What is a moderate ARDS?
100-200 P/F ratio which is
What is a severe ARDS
Less than 100 P/F ratio
What test should be done to rule out in ARDS?
Echocardiogram to rule out cardiogenic pulmonary oedema
Swangon’s catheter to obtain pulmonary capillary wedge pressure
What is the management?
Ventilatory support with low tidal volume to protect lungs
Blood transfusions if necessary
Nutritional support
DVT prophylaxis
What is the cardiothoracic ratio in ARDS
It is over 0.5 which is normal cardiac structure
What is the pO2 level for ARDS?
Less than 40kPa
What proves outcome in ARDS?
Prone position on tummy
Muscle relaxation
What is atelectasis?
A common postoperative complication in which basal alveolar collapse can lead to respiratory difficulty.
What causes atelectasis?
When airways become obstructed by bronchial secretions.
What symptoms should raise suspicion for atelectasis?
Dyspnoea and hypoxaemia around 72 hours postoperatively.
What is an effective management strategy for atelectasis?
Positioning the patient upright.
What type of therapy is recommended for managing atelectasis?
Chest physiotherapy: breathing exercises.
Fill in the blank: Atelectasis is suspected in the presentation of _______ and hypoxaemia around 72 hours postoperatively.
dyspnoea
