UMEM Educational Pearls

Title: To Start Or Not To Start Vasopressor????

Keywords: vasopressor, norepinephrine, timing, septic shock (PubMed Search)

Posted: 12/5/2023 by Quincy Tran, MD, PhD (Updated: 11/21/2024)
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Settings: systemic review and meta-analysis

Participants: 2 RCTs, 21 observational studies. Fifteen studies were published between 2020-2023.

There was a total of 25721 patients with septic shock

Outcome measurement: Primary outcome was short-term mortality (ICU, hospital, 28-day, 30-day). Secondary outcomes included ICU LOS, Hospital LOS, time to achieve MAP > 65 mm Hg,

Study Results:

Composite outcome of short term mortality:

20 studies and 17470 patients. Early initiation of vasopressors was associated with lower odds of short term mortality (OR 0.775, 95% CI 0.673-0.893, P<0.001, I2 = 68%).
Early initiation of norepinephrine was associated with lower odds of short term mortality (OR 0.656, 95% CI = 0.544 to 0.790, P <0.001, I2 = 57.2%)
Early initiation of vasopressin was also associated with lower odds of short term mortality (OR 0.685, 95% CI 0.558-0.840, P < 0.001, I2= 57%)

Secondary outcome:

Early vasopressor group was associated with lower odds of RRT use (OR 0.796, 95% CI 0.654-0.968, P = 0.022, I2 = 0%)
Mean Serum lactate levels at 6 hours was similar in early vasopressor group (Mean Difference 0.218, 95% CI -0.642 to 1.079, P = 0.619).
However, mean serum lactate levels at 6 hours was lower in early norepinephrine subgroup (mean difference -0.489, 95% CI -0.863 to -0.115, P = 0.01).

Discussion:

This appears to be a hot topic. When our group did this topic in 2020, there were 8 or 9 studies. Since 2020, there has been a significant increase in the number of publications, although most publications were observation studies.
Early initiation of norepinephrine may reduce fluid overload, not by reducing fluid input, but by improving host inflammatory response, improving endothelial cell barrier stability.
Counter-intuitively, early vasopressor was also found to be associated with lower incidence of arrhythmia, which the authors attributed to shorter duration of vasopressors and lower total dosage.

Conclusion:

More and more studies, although a RCT is still necessary, are showing that early initiation of vasopressor within 1-6 hours of septic shock would be more beneficial to patients with septic shock.

References

Ye E, Ye H, Wang S, Fang X. INITIATION TIMING OF VASOPRESSOR IN PATIENTS WITH SEPTIC SHOCK: A SYSTEMATIC REVIEW AND META-ANALYSIS. Shock. 2023 Nov 1;60(5):627-636. doi: 10.1097/SHK.0000000000002214. Epub 2023 Sep 2. PMID: 37695641.