Final answer:
A nurse's unintentional failure to administer a client's medication that resulted in pulmonary edema constitutes negligence due to a breach of duty of care.
Step-by-step explanation:
The nurse's failure to administer a dose of a client's diuretic drug leading to pulmonary edema may be considered negligence, as it embodies an unintentional failure to perform a healthcare procedure. Negligence in healthcare generally involves a breach of the duty of care that directly causes harm to a patient. In this scenario, the nurse's omission did not include a purposeful failure to perform a procedure, an act of substituting medication, or a failure to follow a prescription in the sense of administering the wrong drug, but it represents a lack of action required to maintain the expected standard of care.
In addition, the provided clinical focus details an incident of drug abuse, which is the use of a drug without the advice of a medical professional and for reasons not originally intended, leading to serious consequences for patients involved, as seen with the hospital employee's malpractice.