First...its hard for me to believe someone who had a spinal fusion did not have an opioid exposure beforehand. Most folks with back pain have been on Vicodin or something prior.
However...we'll go with what you've got.
This is a guideline - every facility I've ever worked in has had specific standing orders with ways to change them.....but here is what I'd recommend:
You've loaded your pt (the initial loading dose should have been about 0.04mg/kg = 3mg, but it took about 30 minutes to do it. You've already set up some anticipatory pain....however, you don't know what happened in PACU or with anesthesia - they may have helped you out here! But...once the pt anticipates pain...they want relief before they know they can't tolerate it.
Your PCA dose should be about 0.02 mg/kg = about 1.3mg with a lockout of 6-10 minutes. Your 4 hour lock out could be 0.3mg/kg (about 20mg) which translates to a 1 hour lock out of 5 mg - lower than what you have, but you can go to a maximum of 40mg/4hr which you're close to. I definitely wouldn't the 4 hour max.
I have real doubts about a spinal fusion which has not had prior narcotics, so I would try to get a clearer picture of preop - what did this pt use for their pain which required a spinal fusion? So I wouldn't change the lock out - keep it at 8 minutes....& up the PCA dose while decreasing the basal infusion. You'd need to check with MD & nursing...if the pt is at all comfortable at any time....the basal is taking care of the previous narcotic load. However...you want to ultimately change that to an as needed narcotic demand...so by decreasing the basal & upping the pca dose...you accomplish what you need. Particularly when physical therapy begins to move pt & start their therapies. One of the things about pcas & pharmacists...they just like to look at the pump settings & not the history or talk with nursing or read nursing notes.
If you are going to develop a plan for a patient - or more importantly, a standardized order, you must learn to develop a way of looking at your patient not just by pump settings. How does your patient respond during all the 24 hours of the day? How frequent & when are the pca doses given? Your care plan should include all of these assessments & a clear understanding of the physicians goals & the nursing assessments. The pca pump settings is ony one aspect of the whole picture.
I hope this helps some..