Table 3 Definitions of early and late norepinephrine group in studies included in the meta-analysis

Bai et al. 2014 [24]

Time from the onset of septic shock to initial norepinephrine administration < 2 h

Time from the onset of septic shock to initial norepinephrine administration ≥ 2 h

Permpikul et al. 2019 [29]

Median time from emergency room arrival to norepinephrine administration was 93 min

Median time from emergency room arrival to norepinephrine administration was 192 min

Elbouhy et al. 2019 [30]

Patients received initial resuscitation as simultaneous administration of crystalloid fluids (the target was 30 mL/kg) together with norepinephrine infusion in a starting dose of 5 μg/min administered in an external jugular peripheral cannula

Patients’ resuscitation included crystalloid fluids (the target was 30 mL/kg) and immediate ICU transfer where the norepinephrine infusion was administered only to patients with mean arterial pressure < 65 mmHg after fluids resuscitation via a central venous catheter

Colon Hidalgo et al. 2020 [25]

The time when vasopressors were initiated ≤ 6 h

The time when vasopressors were initiated > 6 h

Ospina-Tascón et al. 2020 [26]

Vasopressor support initiated within the next hour or even before the first fluid load with resuscitative intention (FRLoad)

Patients in whom vasopressor support was started > 1 h after the FRLoad