Non-catecholamine vasopressors in the treatment of adult patients with septic shock—evidence from meta-analysis and trial sequential analysis of randomized clinical trials

Norepinephrine (NE) has currently been the first-choice vasopressor in treating septic shock despite generally insufficient for patients with refractory septic shock. The aim of this update meta-analysis was to assess the safety and efficacy of a combination of non-catecholamine vasopressors (vasopressin/pituitrin/terlipressin/selepressin/angiotensin II) and NE versus NE in managing adult septic shock patients. We conducted this study of literatures published from the inception to April 30, 2020, using PubMed, Embase, and the Cochrane Library databases without language restriction. Randomized controlled trials comparing NE with non-catecholamine vasopressors among adult septic shock patients were included in this meta-analysis. Pooled effects of relative risk (RR) or standard mean difference (SMD) and corresponding 95% confidence interval (CI) were calculated using a random-effects model. Twenty-three studies covering 4380 participants were finally enrolled. The combined analysis of non-catecholamine vasopressors resulted in a nonsignificant reduction in 90-day/ICU/hospital mortality except for a decreased in 28-day mortality (n = 4217; RR, 0.92; 95% CI 0.86–0.99; P = 0.02). This favorable result was subsequently verified by the subgroup analyses of low risk of bias studies (RR = 0.91, 95% CI = 0.84 to 0.98; P = 0.02) and catecholamine-resistant refractory shock patients group (RR, 0.84; 95% CI = 0.70–1.00; P = 0.048). The pooled analysis of non-catecholamine vasopressors showed a 14% higher success rate of shock reversal at 6 h, a 29% decreased risk of continuous renal replacement therapy, but a 51% increased risk of hyponatremia and a 2.43 times higher risk of digital ischemia. Besides, the pooled data showed that non-catecholamine vasopressors decreased heart rate (HR) (SMD, − 0.43; 95% CI − 0.66 – − 0.19; P < 0.001), serum creatinine (− 0.15; 95% CI − 0.29 – − 0.01; P = 0.04), and the length of mechanical ventilation (MV) (− 0.19; 95% CI − 0.31 – − 0.07; P < 0.01, but there was no significant difference in other parameters. Current pooled results suggest that the addition of NE to non-catecholamine vasopressors was associated with a marginally significant reduction in 28-day mortality. Moreover, they were able to shorten the length of MV, improved renal function, decreased HR, and increased the 6-h shock reversal success rate at the expense of increased the risk of hyponatremia and digital ischemia.