Published
my first guess would be that although the resp are less than 20 prior to intubation the pt is doing some neuro protection of his own by breathing down his CO2 and therefore decreasing his CBF and decreasing some of the probable increased ICP due to possible swelling. After doing a quick search I did find this information "Hyperammonemia with respiratory alkalosis is caused by a urea cycle defect". Without other information it make this alittle more difficult to guess at. let us know.
Hyperammonemia with respiratory alkalosis is caused by a urea cycle defect". After further research DISREGARD this, it is only pertaining to the neonate. I spoke with our fellow and cerebral edema and what I had said about doing some brain protection on his own is most probable cause of this pts hypocarbia.
Granted this is a metabolic problem being liver fx and increased ammonia. With the information provided, I can tell you what the bicarb is and calculating what the gas should be if there is no metabolic component it would be 7.52. So, with the information provided, the pts bicarb is probably slightly elevated because the gas is 7.55 (if you want to know how I got that let me know, otherwise I will assume you know) Most pts that have some neuro component will self compensate (to decreased CO2 therefore decreasing CBF and ICP assuming this is what is happening) esp if they are post TBI or even a coma with maintained resp drive.
So, we can get the information that you want to know from the information provided.
A little update...
I was off work a week and when I returned the pt. had an additional diagnosis of urea cyle disorder. Apparently only a handful of adults have had this diagnosis. Treatment is IV arginine and sodium benzoate, which is the only way we were able to start decreasing ammonia level, with no previous results using lactulose per NGT and enemas, CRRT, and dialysis. Unfortunately, we may not have found this soon enough
Only time will tell.
registeredin06
160 Posts
Liver failure, ammonia in 600's. Otherwise labs okay, with LFT's slightly up. Hepatic coma set in today. When ammonia climbed over 600, concern of airway protection arose. ABG's drawn with pCO2 of 24, O2 70's, pH 7.55. For last 24 hrs, RR