Positive end-expiratory pressure causes increase in which respiratory parameter -
Ans. is 'd' i.e., All of the above * Positive airway pressure therapy means proving positive pressure during breathing. It may be :-1) Positive end-expiratory pressure (PEEP)# PEEP is the positive pressure is applied at the end of expiration during mechanical ventilation. So, PEEP has two features : -i) Positive pressure is applied during expiration (at the end).ii) Used for mechanical ventilation2) Continuous positive Airway pressure (CPAP)# CPAP is application of positive-pressure : -i) During both inspiration and expiration.ii) In spontaneous breathingPulmonary effects of PEEP and CPAP* Positive pressure in PEEP 8c CPAP results in : -i) Re-expansion (recruitment) and stabilization of partially collapsed lung, which causes : -a) Increased FRC, tidal volume & lung compliance.b) Correction of ventilation!perfusion abnormalities - Improved oxygenation.ii) Redistribution ofextravascular lung water from interstitial space between alveoli and endothelial cells towards peri-bronchial and perihilar areas - As fluid moves away from the space between vessels & alveolar space, oxygen can diffuse more easily from alveoli into the blood - Improved arterial oxygenation.Adverse effects of PEEP/CPAP1. Pulmonary* Controlled PEEP or CPAP improve lung compliance and correct ventilation/perfusion abnormalities. However, excessive PEEP or CPAP can overdistend alveoli & bronchi which results in : -i) Increased dead space ventilationii) Reduced lung complianceiii) Increased pulmonary vascular resistance & Right ventricular afterload.iv) Barotrauma (Pneumothorax, pneumopericardium, pneumoperitonium, Subcutaneous emphysema).2. Extrapulmonary* These adverse effects are primary circulatory and are related to transmission of elevated airway pressure to the chest :-i) Decreased cardiac output (due to increased intrathoracic pressure venous return is decreased).ii) Decreased hepatic & renal blood flow (due to decreased cardiac output 8c elevated CVP)iii) Increased ADH & angiotensiniv) Decreased urinary output, GFR and free water clearance (Decrease Renal function).v) Increased ICT (due to increased CVP).
Fundamental Concepts
Lung compliance
FRC
Tidal volume
All of the above
All of the above