How do you measure it?

...interesting to note that the pt was happy to wait for his next dose (ie the 2mg he was given was enough analgesia for the 4 hours) - begs the question of whether he needs his pain meds reassessing...

I's say the 4 hours starts from the time of the 2nd dose.

Ditto

0-10mg q4 hr means 10mg within a rolling 4 hour period.

So if you give 1mg at 1000, and you give 9mg at 1359, you can't turn around and give another 10mg at 1402. Think of it like the tylenol maximum limit - that's within a rolling 24 hour period.

I agree....the 4 hour time period restarts if you give more of the medication. You can't give 18 mg within a 4 hour time period for this patient.

I don't think I've ever given more than 5mg of morphine in a single dose, but I work in peds. Here is how I would do it

I'd give the additional 8mg at 1910 if the patient was in pain, and was breathing well, etc. Since it was just over an hour from the first dose, I would look at it as titrating his dose to a therapeutic level. If at some point before 2130 I reassessed the pt and he was in pain, breathing well, and not looking very medicated (I'd check his pupils) I'd call the doc and get an order for an additional dose. If he was doing ok at 2130 I'd hold off on his next dose, but if he was in pain, breathing well, and looked like he needed the medication I'd go ahead and dose him. If I had any doubts I would start with a lower than 10 dose and titrate up if I had to. If my facility wasn't ok with me making that decision I'd call for an order.

I think the important thing is that the pts pain is controlled safely - part of why you are in a hospital is so that doses and schedules can be adjusted as needed.

Agreed...I look at it as a rolling 24hrs...and would dose accordingly. No second full dose within the 4 hours of getting the rest of the first dose. If the pt was still in pain & wanted meds after the full 10 was given, I would start chatting with the MD. (I, too, work in Peds...and that's a heck of a lot of morphine :D

I guess the part I try to avoid is predicting what I am going to do at 2130, or promising a particular dose at 2130. Doesn't it depend on how the patient looks, what your assessment is at 2130? If the patient is an addict and I tell them I'll give them a particular dose at a particular time, they are going to just sit there and watch the clock and expect the dose no matter what.

At our hospital we have an hour to give the rest of the med (i.e. if the order says 2-4 mg morphine iv Q 4 hr prn for pain, if i give 2 mg because the pain is only moderate and then within an hour pt states his pain is getting worse, I can give another 2 mg. I can repeat the medication in three hours after that.)

Sounds like there is misunderstanding among nurses about what the policy is at your facility.

You really should read the hospital policy. I would have administered the remaining 8mg immediately after the mistaken 2mg dose . This will ensure the patient dosage is S&T. Then I would asses pt after 4h to see If the patient is comfortable. In, addiction if the pt order is prn and he or she seemed find after administration of 2mg I continue to give a lower dose and consult with MD. I am glad my grandmother is (28 year experienced) retired nurse. When I have questions she is there for me