The Diameter Index Safety System (DISS) safeguards against hypoxic gas mixture through hoses that are color coded and diameter indexed from the central supply source into the operating room and anesthesia machine. Wall outlets supply oxygen, nitrous oxide and air at a pressure of 50 to 55 pounds/in2 (psi).
Hofmann elimination is defined as a spontaneous chemical breakdown that occurs at physiological pH and temperature. The process is independent of renal, hepatic or enzymatic function. Nondepolarizing muscle relaxants that undergo Hofmann elimination in whole or part are Atricurium and Cisatricurium.
The chemical reaction is as follows:
- Affects an estimated 3 to 5 per 100,000 live births.
- Mortality rate among affected parturients is as high as 85% and accounts for up to 12% of all maternal deaths.
- Significant and permanent neurologic sequelae are common among survivors.
- Introduction of fetal cells, amniotic fluid, and inflammatory mediators in the maternal circulation are thought to be the cause.
- Presents during labor or the immediate postpartum period with acute hypoxia and hypotension.
Clinical Presentation of AFE:
- Hypotension is a key feature of the disease and is present in 100% of patients with severe disease.The initial transient physiologic response is pulmonary hypertension resulting in hypoxia and right heart failure. Patients who survive the initial insult develop a left heart failure and pulmonary edema
- Hypoxia is an early manifestation of AFE and is thought to arise from acute pulmonary hypertension and ventilation/perfusion mismatch. Pulmonary edema develops later in association with left ventricular dysfunction.
- Disruption of normal clotting cascade occurs in up to two thirds of patients.
Management of AFE:
- Oxygenation: Tracheal intubation, mechanical ventilation, and supplemental oxygen.
- Circulatory support: Fluid resuscitation and pressor support as needed.
- Lines and monitors: Normal ASA monitors plus invasive BP, and PA catheter and/or TEE to assess ventricular function.
- Regular lab studies to aggressively treat coagulopathy.