Would YOU have reported it?

What is the policy for completing incident reports? If the pyxis makes it easy to make mistakes such as this, an event report can be helpful in identifying systems issues that can help with preventing errors in the future, such as placing lookalike/soundalike medications in different drawers- my OR has done that with different strengths of local anesthetics to help with preventing grabbing the wrong strength accidentally.

However, the fact that you are questioning whether or not to report this is a red flag. Medication errors, whether the patient is harmed or not, need to be reported as per the facility's policy. It's part of practicing nursing professionally and ethically to provide the best care to patients; someone potentially getting in trouble needs to take a backseat to that. Medication errors are at times related to systems issues rather than a single person; reporting it can help fix the system and improve patient care. The doctor also should have been notified- sure, the patient seemed fine, but there can be adverse effects of administering the wrong medication that potentially won't show up until later.

Wait I'm confused. How is this a med error?

Because the provider ordered normal saline (isotonic at 0.9%) but the nurse who started the fluids hung half normal saline (hypotonic at 0.45%). Instead of maintaining cellular vs. vascular fluid levels, the hypotonic solution would cause fluid to shift from the vascular system into the cells, possibly leading to cell lysis and vascular volume depletion.

OP, is this correct? I'm confused.

My patient had 1/2 normal saline running at 100 ml/hour when I assessed him after shift report. The physician came in and ordered to discontinue the normal saline and start D5W at 50 ml/hour. Indeed, he had ordered normal saline yesterday. I took down the 1/2 normal saline, hung the D5W at 50/hour and moved on.

Emphasis mine, but it does indeed appear that the order previous day was for normal saline but half normal saline was running.