48 Questions
What is the minimum current required to cause Ventricular Fibrillation?
100 microamps
What is the effect of a 10 milliamp current on a human?
Maximal harmless current
What is the minimum current required for direct contact with the heart to cause ventricular fibrillation?
100 microamps
What is the maximum recommended leakage current?
10 microamps
What is the purpose of an isolation transformer?
To supply sensitive equipment
Why don't birds on power lines normally get shocked?
Because they are not part of an electrical circuit
What is the difference between macroshock and microshock?
Macroshock involves large current flows, microshock involves small current flows
What is the maximum leakage current allowed in Operating Room equipment?
10 microamps
What is the effect of a 50 milliamp current on a human?
All of the above
What is the frequency of AC current that is considered more dangerous?
60 Hz
Why is AC current at 60 Hz considered more dangerous than DC current?
Because it can excite contractile cells
What is the term for the current above which sustained muscular contraction occurs?
Let-go current
What is required to receive an electrical shock?
Contact with both a high-voltage source and a grounded object
What is the term for current that leaks out of an intended circuit and flows through some alternate path?
Leakage current
What is the definition of electricity?
The flow of electrons
What is a conductor?
Any substance that permits the flow of electrons
What is the difference between a DC circuit and an AC circuit?
DC circuits have electrons flowing in one direction, while AC circuits have electrons flowing in both directions
What is the unit of measurement for voltage?
Volts
What is the formula to calculate voltage?
V = I x R
What is the resistance of a circuit that requires a voltage of 100V to produce a current of 100mA?
100000 Ohms
What is the analogy used to describe the relationship between voltage, current, and resistance?
Water flow analogy
What is the resistance of a circuit with a voltage of 100 volts and a current of 0.1 amps?
1000 ohms
What is the formula for blood pressure in terms of cardiac output and systemic vascular resistance?
BP = CO x SVR
What is the purpose of a capacitor in electrical circuits?
To store charge
What is the term for the unintended transfer of current to non-target tissue through intact insulation during a laparoscopic procedure?
Capacitive coupling
Why is it important to beware of nose rings and other jewelry during surgical procedures?
They can cause electrical shock
What is the main cause of electrical shock injuries or deaths?
When voltage pushes electrons through the human body
What was the cause of a 2014 surgical blaze, according to a report by the state Health Department?
A communications failure between the surgeon and anesthesiologist
What is the primary function of an isolation transformer?
To protect secondary circuits and individuals from electrical shocks
What is the purpose of a Line Isolation Monitor?
To monitor the current flow from the isolated power supply to the ground
What is the maximum harmless current that triggers an alarm in a Line Isolation Monitor?
5 mA
What is the frequency range of electric currents used in electrocautery devices?
0.1-3 Megahertz
What is the advantage of bipolar electrocautery?
It does not return a grounding pad
What is the purpose of the return electrode in monopolar electrocautery?
To return current from the wound
What is the advantage of using a large surface area return electrode in electrocautery?
It decreases the risk of burns at the current point of exit
What is the element in electrocautery devices?
Hot
What is the effect of electrocautery devices on monitors?
They cause electrical interference with the monitors
What is the benefit of electrocautery in surgery?
It is excellent for pinpoint hemostasis
What is the primary function of an isolation transformer in an operating room?
To protect secondary circuits and individuals from electrical shocks between energized conductors and earth ground
What is the purpose of the Line Isolation Monitor in an operating room?
To monitor the potential for current flow from the isolated power supply to the ground
What is the characteristic of the return electrode in monopolar electrocautery?
It is attached to the patient's skin at a location away from the surgical site
What is the advantage of using bipolar electrocautery?
It does not require a return electrode attached to the patient
What is the frequency range of electric currents used in electrocautery devices?
0.1-3 Megahertz
What is the maximum harmless current that triggers an alarm in a Line Isolation Monitor?
5 mA
What is the purpose of the large surface area return electrode in electrocautery?
To reduce the risk of electrical shock
What is the element in electrocautery devices that is hot during use?
The active electrode
What happens if the Line Isolation Monitor alarm sounds?
The last piece of equipment should be disconnected and inspected
What is the primary difference between bipolar and monopolar electrocautery?
The presence of a return electrode attached to the patient
Test your knowledge of electrical safety in the operating room, including principles of electricity, electrical shock hazards, and definitions of key terms. Learn about conductors, insulators, current, and circuits. Essential for medical professionals working in the OR.
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