K+ and insulin

[suzysuzy]

I am confused....most of the nurses at my open heart unit are always asking what the glucose is on istat when the 2nd nurse reports the K+ - ok males sense but then I have heard 5 sepeate times in 3 weeks that they are not replacing the K+ b/c the glucose is high and they will be starting an insulin gtt which will help???? I thought insulin would push K+ back into the cells lowering the serum K+. Here's an example, pt arrives from or (200 in auto bag - I know will raise K+ r/t cardioplegic solution etc but we don't auto for 4 hours), K+2.4, Creat 0.8 (obviously would be a little less generous with the K+ replacement if CRF - by the way we have these global recovery orders for K+ and many other things with no specified labs for replacement etc - something that has been disussed but has not changed for now...so K+, Mg++ etc doses and to give or not all up to RN during recovery hours - md on unit fo r5 minutes only - no midlevels, anesthesia or docs remain so nurse is it except when all hell breaks loose and we can get the surgeron by phone)...anyway, BG 237 (we start stat insulin gtts with boluses on all post-op pts >150 on arrival) and nurse says well his sugar is high so I am not going to give him any K+. ??????? Further, pt was acidotic ph 7.2 (mixed resp met) and 2 amps bicarb given + vent adjusted (Ok so improving the acidoiss should also lower the K+ right???). Anyway, couple hours later lots of ectopy, lido given and nurse decides to give KCL. Pt ok. But, I have heard the whole well his sugar is high so I am not replacing the K+ for people with arriving BG 140's-200's and K+ 2-3.6 (our mds like over 4). Please explain --- am I missing something -__ I have asked but get different responses - some say treat as K+ will drop even lower once treat hyperglycemia and some say opposite. I've haven't been there long enough to recover by myself (have to have been in unit 5 years) but I would have given 40meq K+ on arrival (obviously after everything else started) b/c would expect it to drop even lower as treated BG and acidosis (would have given it even if pt wasn't acidotic - don't know if they were really alkalotic) and don;t think the auto 4 hours later would really increase it that much. So....what would you have done????? Thanks for helping increase my understanding.