Consider the following statements regarding Acute Respiratory Distress Syndrome (ARDS): 1. Exudative phase lasts from day 7 to day 21 after exposure to a precipitating risk factor. 2. Proliferative phase is characterised by proliferation of type II pneumocytes. 3. Low tidal volume ventilation (6 mL/kg body weight) has significantly lower mortality in management as compared to high tidal volume ventilation (12 mL/kg body weight). 4. PaO$_2$/FiO$_2$ $\le$ 100 mm Hg is classified as severe AIDS. Which of the statements given above are correct?
ARDS Key Statements Analysis
This analysis evaluates the accuracy of statements concerning Acute Respiratory Distress Syndrome (ARDS) to identify the correct ones.
Detailed Statement Breakdown
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Statement 1: Exudative Phase Duration.
The exudative phase of ARDS typically occurs within the first 1 to 7 days following the initial precipitating risk factor. The statement's specified duration (day 7 to day 21) is incorrect for this phase. -
Statement 2: Proliferative Phase Characteristics.
The proliferative phase, which generally begins around day 7-10 and can last for several weeks, is indeed characterized by the proliferation and differentiation of type II pneumocytes. These cells play a vital role in repairing the alveolar epithelium. Thus, the statement is correct. -
Statement 3: Mechanical Ventilation Efficacy.
Management of ARDS frequently involves mechanical ventilation. Extensive clinical research, notably the ARMA trial, has established that employing low tidal volume ventilation (e.g., 6 mL/kg of predicted body weight) significantly reduces mortality rates when compared to higher tidal volume ventilation (e.g., 12 mL/kg). The statement accurately reflects this established practice. -
Statement 4: Severe ARDS Classification.
The Berlin definition provides criteria for classifying ARDS severity using the ratio of arterial oxygen tension to fraction of inspired oxygen (PaO$_2$/FiO$_2$). A ratio of $\le$ 100 mm Hg is classified as severe ARDS. Assuming the term 'AIDS' in the statement is a typographical error for 'ARDS', the statement is correct.
Summary of Correct Statements
Based on the evaluation:
- Statement 1 is incorrect.
- Statement 2 is correct.
- Statement 3 is correct.
- Statement 4 is correct.
Therefore, the correct statements are 2, 3, and 4.
Important Questions from Ventilator Management
- All of the following predispose to Acute Respiratory Distress Syndrome EXCEPT:
A 60 year old man with pneumonia is unconscious and has a PaO$_2$ of 50 mm Hg. The preferred modality of treatment for him is:
- A 40-year-old patient of bronchial asthma presents with acute severe breathlessness. Indications for giving him assisted ventilation for acute severe asthma include which of the following?
