A FEW FACTS ABOUT THE ADJUSTABLE PRESSURE LIMITING (APL) VALVE [📖]

🔗 When fully opened the APL valve maintains a pressure of around 1.5 cm of H2O 

🔗 As we close the APL valve, the pressure builds up inside and there is a safety overpressure release valve is incorporated in modern APL valves, to avoid this rising to dangerous levels. This system starts opening at  a pressure of 30 cm of H2O and fully opens at 60 cm of H2O and at this point, allows the gases to escape at a rate of 50L/ min 

🔗 When the patient inspires, the APL valve , if intact, should not allow entrainment of air from the environment 

🔗As the modern reservoir bags are less compliant, compared to the older latex ones, the importance of overpressure relief valves has increased

🔗 As the APL valve will always produce a small resistance to expiration, even when maximally loosened, it helps to maintain PEEP

#Anesthesia , #Anaesthesia

AMNIOTIC FLUID EMBOLISM (AFE) : WHICH ARE THE CONSISTENT CLINICAL FEATURES @ PRESENTATION❓

🎯 Hypotension , Hypoxemia and DIC are hallmarks (Ⓜ️NEMO> "AFE is Highly Dangerous")

🎯 Hypotension & Fetal Distress occur in 100% of cases

🎯 DIC occur in 83% and indicate a bad prognosis 

🎯 Cardiac arrest occur in around 87% of patients

🎯 Mortality is >60% ; it has been observed that only 15% survive with intact neurological function 

🎯 Pulmonary Hypertension, CHF and DIC are key events in the pathogenesis

🎯 Pulmonary edema (occur in >90% of cases),Dyspnoea (occur in 49%) & Bronchospasm (occur in 15%) are the respiratory signs

Reference: Dedhia JD, Mushambi M. Amniotic fluid embolism. Contin Educ Anaesth Crit Care Pain. 2007; 7(5): 152–156. Gist RS, Stafford IP, Leibowitz AB et al. Amniotic fluid embolism. Anaesth Analg. 108(5): 1599–1602.