A Pressor for Bleeding, Not for Vasoplegia
His blood pressure won't hold even with the bleeding source controlled and blood products running. The vasopressor literature everyone reaches for by habit was built on septic shock — a different physiology, borrowed here without much to confirm it transfers.
R.P., a 47-year-old structural engineer, fell from a ladder he had climbed to inspect scaffolding — a detail his wife offers the ICU team mostly to explain why he is going to be furious about missing tomorrow's site walkthrough. He underwent emergency splenectomy for a shattered spleen, source control achieved and balanced blood products running for the past ninety minutes, and his mean arterial pressure has still not held above 60 on norepinephrine titrated to 0.4 mcg/kg/min — a dose the ICU team considers high for bleeding that is supposedly already stopped. His hemoglobin has stabilized at 9.1 g/dL with transfusion, which is what makes the persistent hypotension puzzling rather than simply unresolved bleeding. His lactate points the same way and further: 3.2, down from 6.4 before the operation, meaning his tissue perfusion is recovering on the numbers even while the pressure that is supposed to be delivering it has not. The two are moving apart rather than together, and nothing in his history explains why. He is 47, with no cardiac disease, no chronic hypertension, and no baseline that would predict the way his vasculature is behaving now that the bleeding itself has stopped.
Persistent vasodilation after the bleeding source is controlled and volume is adequately replaced is a real, if less-discussed, feature of hemorrhagic shock physiology — prolonged hypoperfusion can produce a relative vasopressin deficiency, mirroring the mechanism better characterized in septic shock, where endogenous vasopressin stores become depleted under sustained stress. The trial evidence for adding vasopressin as an adjunct, however, comes almost entirely from septic shock literature like the VANISH trial, which found no significant difference in kidney-failure-free days between vasopressin and norepinephrine as initial septic-shock therapy — a genuinely different population and a different primary shock mechanism than his. Whether that evidence transfers to refractory hemorrhagic shock specifically is not something a randomized trial has actually tested; the physiologic argument for trying it here is real, but it remains an extrapolation rather than a demonstrated finding for this exact clinical picture.
In the ICU, ninety minutes after source control
I'd continue escalating norepinephrine before reaching for a second agent — it's first-line across shock states broadly, and its alpha-1 mechanism directly addresses vasodilated hypotension regardless of whether the underlying driver is sepsis or hemorrhage.
He's already at a dose I'd consider high with volume adequately replaced and the source controlled — I'd add vasopressin now rather than continuing to climb the norepinephrine curve. Prolonged hemorrhagic shock can produce a relative vasopressin deficiency the same way sustained septic stress does, and a distinct V1 receptor pathway may recruit tone the alpha-1 pathway alone isn't reaching at this point.
Worth naming plainly: the strongest trial evidence for vasopressin as an adjunct, VANISH, is a septic shock trial, not a hemorrhagic shock trial. The physiologic argument for trying it here is real and I'm not against it, but we're extrapolating across shock etiologies without a trial that's actually tested this population — that's a genuinely different epistemic footing than treating this as established, and it should be named rather than assumed just because the drug is the same.
Agreed: fixed-dose vasopressin added as an adjunct while norepinephrine was held rather than further escalated. His MAP rose above 65 within twenty minutes and norepinephrine requirement was successfully weaned over the following six hours.
Explicitly not agreed, and left unresolved rather than smoothed over: whether the improvement reflected a genuine vasopressin-deficiency mechanism specific to his hemorrhagic shock, or simply additional receptor coverage that would have worked from any second pressor added at that point — the team had no way to distinguish the two from a single patient's response, and the pharmacologist's caveat about extrapolated evidence was recorded as still standing regardless of the outcome.