TY - CHAP M1 - Book, Section TI - The Operating Room Environment A1 - Butterworth IV, John F. A1 - Mackey, David C. A1 - Wasnick, John D. PY - 2022 T2 - Morgan & Mikhail’s Clinical Anesthesiology, 7e AB - KEY CONCEPTS A pressure of 1000 pounds per square inch (psig) indicates an E-cylinder that is approximately half full and represents 330 L of oxygen. The only reliable way to determine the residual volume of nitrous oxide is to weigh the cylinder. To discourage incorrect cylinder attachments, cylinder manufacturers have adopted a pin index safety system. A basic principle of radiation safety is to keep exposure “as low as reasonably practical” (ALARP). The principles of ALARP optimize protection from radiation exposure by the use of time, distance, and shielding. The magnitude of a leakage current is normally imperceptible to touch (<1 milliampere [mA] and well below the fibrillation threshold of 100 mA). If the current bypasses the high resistance offered by skin, however, and is applied directly to the heart (microshock), current as low as 100 microamperes (μA) may be fatal. The maximum leakage allowed in operating room equipment is 10 μA. To reduce the chance of two coexisting electrical faults, a line isolation monitor measures the potential for current flow from the isolated power supply to the ground. Basically, the line isolation monitor determines the degree of isolation between the two power wires and the ground and predicts the amount of current that could flow if a second short circuit were to develop. Almost all surgical fires can be prevented. Unlike medical complications, fires are a product of simple physical and chemical properties. Occurrence is guaranteed given the proper combination of factors but can be almost entirely eliminated by understanding the basic principles of fire risk. The most common risk factor for surgical fire relates to the open delivery of oxygen. Administration of oxygen in concentrations of greater than 30% should be guided by the clinical presentation of the patient and not by protocols or habits. The sequence of stopping gas flow and removal of the endotracheal tube when a fire occurs in the airway is not as important as ensuring that both actions are performed immediately. Before laser surgery is begun, the laser device should be in the operating room, warning signs should be posted on the doors, and protective eyewear should be issued. The anesthesia provider should ensure that the warning signs and eyewear match the labeling on the device because laser protection is specific to the type of laser. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accessanesthesiology.mhmedical.com/content.aspx?aid=1190603093 ER -