Final answer:
To defibrillate a victim in water, remove them from the water, administer CPR if needed, and then use an AED for defibrillation. An AED provides instructions, analyzes heart rhythm, and delivers a shock automatically. During open-heart surgery, apply voltage as per Ohm's Law based on required current and pathway resistance.
Step-by-step explanation:
If you find a victim in water and need to defibrillate them, it's essential to first ensure the person is out of the water. Defibrillation in water is unsafe and ineffective. Instead, remove the person from the water as quickly as possible. Once on stable ground, check for a pulse and breathing; if none, begin CPR immediately as it can be crucial before defibrillation. When the area is dry and safe, use an automated external defibrillator (AED) if available. The AED will provide verbal instructions and will automatically diagnose the patient's heart rhythm, delivering a shock if necessary.
During open-heart surgery, if a defibrillator is required, you will calculate the necessary voltage using Ohm's Law (Voltage = Current × Resistance). For a pathway resistance of 500 ohms and a needed current of 10.0 mA, you would apply a voltage of 5 volts (10.0 mA × 500 ohms = 5000 millivolts or 5 volts).