Final answer:
When a patient experiences cardiac arrest again after reanimation, CPR must be restarted. Decisions involving brain dead patients are complex, as brain death is irreversible. Techniques like controlled hypothermia can be used post-arrest to reduce heart damage.
Step-by-step explanation:
If your patient falls into cardiac arrest again after being successfully reanimated, you should indeed restart the cardiopulmonary resuscitation (CPR) protocol from the beginning. Each cardiac arrest event is unique, and the patient must be assessed and treated according to their current condition. In such cases, it would also be essential to check for the reversibility of the conditions that might have caused the re-arrest.
Concerning scenarios involving brain dead patients, these represent a different level of medical and ethical complexity. The term 'brain dead' refers to a complete and irreversible loss of brain function, and in such cases, restarting CPR would not be appropriate.
For patients undergoing open-heart surgery, if a defibrillator is needed, the voltage to be applied can be determined by Ohm's Law, which states that voltage equals current times resistance. Given a resistance of 500 ohms and a needed current of 10.0 mA, the voltage required would be 5 volts.
Lastly, if there is a total lack of normal electrical activity in the heart, you would expect the heart rate (pulse) to cease, leading to cardiac arrest. The medical team, including the surgeon, nurse, and anesthesia professional, must review the patient's care plan to be prepared for such possibilities.
Controlled hypothermia is a technique used in some emergency departments where the patient's body temperature is lowered to reduce cardiac damage and workload after a cardiac arrest. The patient is typically cooled to approximately 91 degrees Fahrenheit, which slows their metabolic rate and reduces the blood demand of their organs.
In an unfortunate case where red blood cells have been destroyed after an injection of saline solution, it suggests that the solution may not have been isotonic as it should have been. An isotonic solution has the same salt concentration as the body's cells and blood and would not cause red blood cell destruction, which is more typical of a hypertonic or hypotonic solution.