Written by Clay Smith
Push-dose phenylephrine improved early hemodynamic stability but was associated with increased ICU mortality in septic shock patients.
Why does this matter?
Sometimes, as we wait for a norepinephrine drip, we may use a push-dose pressor like phenylephrine to temporarily stabilize MAP. This seems to work in many cases. Phenylephrine is often used in patients with low vascular tone, such as those in a perioperative setting, but its use in septic shock may be very different. Is use of a pure alpha-1 agonist effective and safe in these patients?
Don’t push it…?
This was a retrospective multicenter study of patients with septic shock. Out of 1,317 patients, 181 received push-dose phenylephrine. They were able to propensity match 141 of these patients in a 1:2 ratio with patients who were otherwise very similar but did not receive push-dose phenylephrine. For the primary outcome of hemodynamic stability at 3 hours, it worked: 28.4% phenylephrine vs. 18.8% no phenylephrine; difference 10% (95%CI 0.9% to 18%); odds of hemodynamic stability nearly doubled, OR 1.8. Hemodynamic stability was defined as the time when the MAP was ≥65 for 6 hours with no increase in continuous vasoactive infusions. There was no difference in stability by hour 12. Unfortunately, push-dose phenylephrine was associated with increased ICU mortality, aOR 1.88 (95% CI 1.1-3.21). Even with propensity matching, there could have been a confounding variable – patients received push-dose phenylephrine in a non-random way, for a reason, and may have simply been sicker. This gives me pause. What if we just anticipated the need for a norepinephrine drip sooner? That might be a better solution.
Effect of phenylephrine push prior to continuous infusion norepinephrine in patients with septic shock. Chest. 2020 Dec 11;S0012-3692(20)35353-8. doi: 10.1016/j.chest.2020.11.051. Online ahead of print.
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