Respiratory physiology Flashcards
(23 cards)
Alternative delivery method of Salbutamol if nebulization isn’t possible?
MDI + Spacer, 4 puffs every 10 mins until improvement
Side effects off nebulised salbutamol ?
- Tremors
- Anxiety
Is there an indication for oral Leukotriene antagonist like Motelukast in acute severe asthma?
No
Function and composition of Heliox?
- Oxygen & Helium
- Decreases airway resistance
- Heliox use requires recalibration of flow meter
- No role in the management of asthma
How to estimate static Auto-PEEP in dynamic hyperinflation ?
At end-expiratory pause and measuring rise in airway pressure
Pathophysiology of acute severe asthma?
- Airway resistance is very high
- Lung hyperinflation
- End-expiratory volume may be close to TLC
- Requires prolonged expiratory time
- Dynamic hyperinflation worsened by high PEEP
Complications of dynamic hyperinflation in acute severe asthma?
- Hypotension
- Ventilatory compromise
Ventilatory strategy in acute severe asthma ?
- Short I:E ratio - Prolonged expiratory time
- Low PEEP
- Permissive hypercapnia
Ventilatory strategy is ARDS?
- Inverse ratio ventilation which helps in lung recruitment
Delivery of drugs using pMDI in ventilated patients and HME filter? (Pressurised Metered Dose Inhaler)
- HME filter should be removed from between the ETT and ventilator
- pMDI should be connected to the inspiratory limb
- Increased dead-space if pMDI is between the ETT & Y-connector
- pMDI actuated at inspiration
- HME decreases the delivery of pMDI
How is duty cycle calculated in asthmatic patients?
Calculated as inspiratory time / Total breath time (Time spent in inspiation / Expiration)
This should be longer to increase delivery of drug
Inspiratory flow rate of 30-50L/min is appropriate
Disadvantages of high duty cycle?
- Increased dynamic hyperinflation
- Increased auto-PEEP
Steroid management in acute severe asthma?
- Short course of 5 days may be stopped without tapering
- Tapering not required provided inhaled corticosteroids are continued
What’s the gold standard test for diagnosis of Covid-19
- NAAT - Nucleic Acid Amplification test.
- Detects generic sequence in DNA or RNA
- RT-PCR - This is a type of NAAT - reverse transcriptase polymerase chain reaction
Covid-19 diagnosis using swabs?
- Nasopharyngeal swab true positive highest between 0-4 days.
- Chances of true positive drops between 10-14 days
- Induced sputum for testing is not recommended
What is “Bias flow”~?
- Small constant flow in the circuit
- Same flow reaches expiratory end if no pt effort
Rapid antigen detects?
- Nucleocapside protein (N-Protein)
- It is highly specific
What is the Nucleic Acid Amplification Test?
- Detects a particular genetic sequence in DNA or RNA
- RNA or DNA polymerase is one way of amplification
- RT-PCR is a type of NAAT
- NAAT is the gold standard for diagnosis of covid
Demographic distribution of covid variants?
- Alpha = UK
- Beta = South Africa
- Gamma = Brazil/Japan
- Delta = India
- Epsilon = California
Peak window for the infectiousness for transmission of covid?
Two days before onset of symptoms and one day after onset of symptoms
What is the median duration of RNA infection ?
It is 18 days from onset of symptoms
Effect of Tocilizumab in management for Covid-19?
- Increased levels of circulating interleukin-6 (peak levels 3-5 days)
- Increased risk of encephalopathy
- Increased risk of opportunistic infections
- CRP suppression for 14 days
What is antibody dependent enhancement in Covid-19 patients?
SARS COV-2 binding to ineffective antibody and hence enhancing viral entry into host cells.
