Search
Subscribe to daily UMEM Pearls (FREE!) via:
Norepinephrine is widely viewed as the first line vasopressor for many types of shock, including undifferentiated shock and septic shock. But as the norepinephrine dose escalates, a perennial question is when to add a second agent, most commonly vasopressin. Based in part on trials like VASST and VANISH, a norepinephrine dose of roughly 0.1-0.2 mcg/kg/min is commonly cited as the time to add on vasopressin.
The VASSPR study was a cluster crossover randomized trial comparing lower (0.1 mcg/kg/min of norepinephrine) vs higher (0.4 mcg/kg/min of norepinephrine) threshold for initiation vasopressin in septic shock patients and was published in JAMA just a few weeks ago.
Bottom Line: This relatively large, high-quality study found no mortality benefit for initiating vasopressin when at a norepinephrine dose of 0.1 mcg/kg/min (or equivalent), which is a common practice, vs initiating vasopressin when at a norepinephrine dose of 0.4 mcg/kg/min. So whether you choose to stick with the current threshold of roughly 0.1-0.2 of norepi that many of us use as your queue to start a second agent, or wait a little later up to 0.4, that's a reasonable approach. Equipoise remains as to the benefit of adding a second agent and when it should be initiated. Of note, the surviving sepsis guidelines say 0.25-0.5 mcg/kg/min, so you also have support from those guidelines if you choose to wait.
References
https://jamanetwork.com/journals/jama/article-abstract/2855462