My Husband Is One Month Post-op Laminectomy And Lumbar Fusion.

My husband is one month post-op laminectomy and lumbar fusion. He is doing well and Continental to imprive, however he wakes up in the night very sweaty, mostly on his trunk area. I remember him doing this after knee replacement, and I'm wondering if it's anesthesia or pain med use before surgery related. He has no kidney or lung symptoms or fever.