Bench-to-bedside review: Vasopressin in the management of septic shock.
ABSTRACT: This review of vasopressin in septic shock differs from previous reviews by providing more information on the physiology and pathophysiology of vasopressin and vasopressin receptors, particularly because of recent interest in more specific AVPR1a agonists and new information from the Vasopressin and Septic Shock Trial (VASST), a randomized trial of vasopressin versus norepinephrine in septic shock. Relevant literature regarding vasopressin and other AVPR1a agonists was reviewed and synthesized. Vasopressin, a key stress hormone in response to hypotension, stimulates a family of receptors: AVPR1a, AVPR1b, AVPR2, oxytocin receptors and purinergic receptors. Rationales for use of vasopressin in septic shock are as follows: first, a deficiency of vasopressin in septic shock; second, low-dose vasopressin infusion improves blood pressure, decreases requirements for norepinephrine and improves renal function; and third, a recent randomized, controlled, concealed trial of vasopressin versus norepinephrine (VASST) suggests low-dose vasopressin may decrease mortality of less severe septic shock. Previous clinical studies of vasopressin in septic shock were small or not controlled. There was no difference in 28-day mortality between vasopressin-treated versus norepinephrine-treated patients (35% versus 39%, respectively) in VASST. There was potential benefit in the prospectively defined stratum of patients with less severe septic shock (5 to 14 ?g/minute norepinephrine at randomization): vasopressin may have lowered mortality compared with norepinephrine (26% versus 36%, respectively, P = 0.04 within stratum). The result was robust: vasopressin also decreased mortality (compared with norepinephrine) if less severe septic shock was defined by the lowest quartile of arterial lactate or by use of one (versus more than one) vasopressor at baseline. Other investigators found greater hemodynamic effects of higher dose of vasopressin (0.06 units/minute) but also unique adverse effects (elevated liver enzymes and serum bilirubin). Use of higher dose vasopressin requires further evaluation of efficacy and safety. There are very few studies of interactions of therapies in critical care--or septic shock--and effects on mortality. Therefore, the interaction of vasopressin infusion, corticosteroid treatment and mortality of septic shock was evaluated in VASST. Low-dose vasopressin infusion plus corticosteroids significantly decreased 28-day mortality compared with corticosteroids plus norepinephrine (44% versus 35%, respectively, P = 0.03; P = 0.008 interaction statistic). Prospective randomized controlled trials would be necessary to confirm this interesting interaction. In conclusion, low-dose vasopressin may be effective in patients who have less severe septic shock already receiving norepinephrine (such as patients with modest norepinephrine infusion (5 to 15 ?g/minute) or low serum lactate levels). The interaction of vasopressin infusion and corticosteroid treatment in septic shock requires further study.
Project description:<h4>Purpose</h4>It is not clear whether vasopressin versus norepinephrine changed mortality in clinical practice in the Vasopressin and Septic Shock Trial (VASST) coordinating center hospital after VASST was published. We tested the hypothesis that vasopressin changed mortality compared to norepinephrine using propensity matching of vasopressin to norepinephrine-treated patients in the VASST coordinating center hospital before (SPH1) and after (SPH2) VASST was published.<h4>Methods</h4>Vasopressin-treated patients were propensity score matched to norepinephrine-treated patients based on age, APACHE II, respiratory, renal, and hematologic dysfunction, mechanical ventilation status, medical/surgical status, infection site, and norepinephrine dose. The propensity score estimated the probability that a patient would have received vasopressin given baseline characteristics. For sensitivity analysis, we then excluded patients who had underlying severe congestive heart failure. The primary outcome was 28-day mortality.<h4>Results</h4>Vasopressin- and norepinephrine-treated patients were similar after matching in SPH1 (pre-VASST); vasopressin-treated patients (<i>n</i> =?158) had a significantly higher mortality than norepinephrine-treated patients (<i>n</i> =?158) (60.8 vs. 46.2%, <i>p</i> =?0.009). In SPH2 after matching, the 28-day mortality rates were not significantly different; 31.2% and 26.9% in the vasopressin (<i>n</i> =?93) and norepinephrine (<i>n</i> =?93) groups, respectively (<i>p</i> =?0.518). The day 1 vasopressin dose in SPH1 vs. SPH2 was 0.036 units/min (SD 0.009) vs. 0.032 units/min (SD 0.005), <i>p</i>?=?0.001, significantly lower in SPH2 after VASST.<h4>Conclusions</h4>Before VASST, vasopressin use was associated with increased mortality compared to norepinephrine in the VASST coordinating center hospital. After VASST, there was no difference in mortality between vasopressin- and norepinephrine-treated patients. This may be the first retrospective propensity-matched cohort study of a sepsis treatment in a center that had previously coordinated a large pivotal randomized controlled trial of that treatment and could be a useful approach for other sepsis therapies.<h4>Trial registration</h4>Registration: ISRCTN94845869.
Project description:INTRODUCTION: Catecholamines are the most used vasopressors in vasodilatory shock. However, the development of adrenergic hyposensitivity and the subsequent loss of catecholamine pressor activity necessitate the search for other options. Our aim was to evaluate the effects of vasopressin and its analog terlipressin compared with catecholamine infusion alone in vasodilatory shock. METHODS: A systematic review and meta-analysis of publications between 1966 and 2011 was performed. The Medline and CENTRAL databases were searched for studies on vasopressin and terlipressin in critically ill patients. The meta-analysis was limited to randomized controlled trials evaluating the use of vasopressin and/or terlipressin compared with catecholamine in adult patients with vasodilatory shock. The assessed outcomes were: overall survival, changes in the hemodynamic and biochemical variables, a decrease of catecholamine requirements, and adverse events. RESULTS: Nine trials covering 998 participants were included. A meta-analysis using a fixed-effect model showed a reduction in norepinephrine requirement among patients receiving terlipressin or vasopressin infusion compared with control (standardized mean difference, -1.58 (95% confidence interval, -1.73 to -1.44); P < 0.0001). Overall, vasopressin and terlipressin, as compared with norepinephrine, reduced mortality (relative risk (RR), 0.87 (0.77 to 0.99); P = 0.04). Vasopressin compared with norepinephrine decreased mortality in adult patients (RR, 0.87 (0.76 to 1.00); P = 0.05) and in patients with septic shock (42.5% vs. 49.2%, respectively; RR, 0.87 (0.75 to 1.00); P = 0.05; number needed to treat, 1 to 15). There was no difference in adverse events between the vasopressin and control groups (RR, 0.98 (0.65 to 1.47); P = 0.92). CONCLUSIONS: Vasopressin use in vasodilatory shock is safe, associated with reduced mortality, and facilitates weaning of catecholamines. In patients with septic shock, use of vasopressin compared with norepinephrine may also decrease mortality.
Project description:Recent clinical data suggest that early administration of vasopressin analogues may be advantageous compared to a last resort therapy. However, it is still unknown whether vasopressin and terlipressin are equally effective for hemodynamic support in septic shock. The aim of the present prospective, randomized, controlled pilot trial study was, therefore, to compare the impact of continuous infusions of either vasopressin or terlipressin, when given as first-line therapy in septic shock patients, on open-label norepinephrine requirements.We enrolled septic shock patients (n = 45) with a mean arterial pressure below 65 mmHg despite adequate volume resuscitation. Patients were randomized to receive continuous infusions of either terlipressin (1.3 microg.kg-1.h-1), vasopressin (.03 U.min-1) or norepinephrine (15 microg.min-1; n = 15 per group). In all groups, open-label norepinephrine was added to achieve a mean arterial pressure between 65 and 75 mmHg, if necessary. Data from right heart and thermo-dye dilution catheterization, gastric tonometry, as well as laboratory variables of organ function were obtained at baseline, 12, 24, 36 and 48 hours after randomization. Differences within and between groups were analyzed using a two-way ANOVA for repeated measurements with group and time as factors. Time-independent variables were compared with one-way ANOVA.There were no differences among groups in terms of systemic and regional hemodynamics. Compared with infusion of .03 U of vasopressin or 15 microg.min-1 of norepinephrine, 1.3 microg.kg-1.h-1 of terlipressin allowed a marked reduction in catecholamine requirements (0.8 +/- 1.3 and 1.2 +/- 1.4 vs. 0.2 +/- 0.4 microg.kg-1.min-1 at 48 hours; each P < 0.05) and was associated with less rebound hypotension (P < 0.05). At the end of the 48-hour intervention period, bilirubin concentrations were higher in the vasopressin and norepinephrine groups as compared with the terlipressin group (2.3 +/- 2.8 and 2.8 +/- 2.5 vs. 0.9 +/- 0.3 mg.dL-1; each P < 0.05). A time-dependent decrease in platelet count was only observed in the terlipressin group (P < 0.001 48 hours vs. BL).The present study provides evidence that continuous infusion of low-dose terlipressin--when given as first-line vasopressor agent in septic shock--is effective in reversing sepsis-induced arterial hypotension and in reducing norepinephrine requirements.
Project description:Septic shock remains associated with significant mortality rates. Arginine vasopressin (AVP) and analogs with V1A receptor agonist activity are increasingly used to treat fluid-resistant vasodilatory hypotension, including catecholamine-refractory septic shock. Clinical studies have been restricted to healthy volunteers and catecholamine-refractory septic shock patients excluding subjects with cardiac co-morbidities because of presumed safety issues. The novel selective V1A receptor agonist selepressin, with short half-life, has been designed to avoid V2 receptor-related complications and long-term V1A receptor activation. Cardiovascular safety of selepressin, AVP, and the septic shock standard of care norepinephrine was investigated in a rabbit model of early-stage atherosclerosis.Atherosclerosis was established in New Zealand White rabbits using a 1% cholesterol-containing diet. Selepressin, AVP, or norepinephrine was administered as cumulative intravenous infusion rates to atherosclerotic and non-atherosclerotic animals.Selepressin and AVP induced a slight dose-dependent increase in arterial pressure (AP) associated with a moderate decrease in heart rate, no change in stroke volume, and a moderate decrease in aortic blood flow (ABF). In contrast, norepinephrine induced a marked dose-dependent increase in AP associated with a lesser decrease in the heart rate, an increase in stroke volume, and a moderate increase in ABF. For all three vasopressors, there was no difference in responses between atherosclerotic and non-atherosclerotic animals.Further studies should be considered using more advanced atherosclerosis models, including with septic shock, before considering septic shock clinical trials of patients with comorbidities. Here, selepressin and AVP treatments did not display relevant cardiovascular risk in early-stage rabbit atherosclerosis.
Project description:<h4>Introduction</h4>Positive hemodynamic response to vasopressin after 6 hours of infusion was independently associated with lower mortality in a previous retrospective study of patients with septic shock. However, factors previously associated with higher plasma vasopressin concentration were not associated with response, and the relationship between plasma vasopressin concentration and hemodynamic response has not been evaluated.<h4>Objectives</h4>This cross-sectional study compared plasma vasopressin concentrations in hemodynamic responders and nonresponders to vasopressin in patients with septic shock to evaluate plasma vasopressin concentration as a therapeutic target for hemodynamic response to vasopressin.<h4>Methods</h4>Adult patients with septic shock were included if they were treated with fixed-dose vasopressin as an adjunct to catecholamines for at least 3 hours. Patients were assigned to groups based on vasopressin response.<h4>Results</h4>Ten hemodynamic responders to vasopressin and eight nonresponders were included. Blood samples for plasma vasopressin concentration were collected 3-6 hours after vasopressin initiation. Baseline characteristics were similar between groups. No difference was detected in plasma vasopressin concentrations between hemodynamic responders and nonresponders (median 88.6 pg/ml [interquartile range (IQR) 84.4-107.5 pg/ml] vs 89.9 pg/ml [IQR 67.5-157.4 pg/ml], p=0.79, respectively). We also did not detect a difference between groups after correcting for vasopressin dose; median vasopressin plasma concentration per 0.01 units/minute of vasopressin infusion for responders was 25.9 pg/ml (IQR 21.8-31.8 pg/ml) versus 29.5 pg/ml (IQR 23.0-57.5 pg/ml, p=0.48) for nonresponders. No difference in clinical outcomes was detected between groups. The findings were robust to multiple sensitivity analyses.<h4>Conclusions</h4>This study does not support the use of plasma vasopressin concentrations as a therapeutic target to predict hemodynamic response to exogenous vasopressin in septic shock.
Project description:Non-mortality septic shock outcomes (e.g., Sequential Organ Failure Assessment score) are important clinical endpoints in pivotal sepsis trials. However, comparisons of observed longitudinal non-mortality outcomes between study groups can be biased if death is unequal between study groups or is associated with an intervention (i.e., informative censoring). We compared the effects of vasopressin versus norepinephrine on the Sequential Organ Failure Assessment score in the Vasopressin and Septic Shock Trial to illustrate the use of joint modeling to help minimize potential bias from informative censoring. Design:Secondary analysis of the Vasopressin and Septic Shock Trial data. Setting:Twenty-seven ICUs in Canada, Australia, and United States. Subjects:Seven hundred sixty-three participants with septic shock who received blinded vasopressin (n = 389) or norepinephrine infusions (n = 374). Measurements and Main Results:Sequential Organ Failure Assessment scores were calculated daily until discharge, death, or day 28 after randomization. Mortality was numerically higher in the norepinephrine arm (28 d mortality of 39% vs 35%; p = 0.25), and there was a positive association between higher Sequential Organ Failure Assessment scores and patient mortality, characteristics that suggest a potential for bias from informative censoring of Sequential Organ Failure Assessment scores by death. The best-fitting joint longitudinal (i.e., linear mixed-effects model) and survival (i.e., Cox proportional hazards model for the time-to-death) model showed that norepinephrine was associated with a more rapid improvement in the total Sequential Organ Failure Assessment score through day 4, and then the daily Sequential Organ Failure Assessment scores converged and overlapped for the remainder of the study period. Conclusions:Short-term reversal of organ dysfunction occurred more rapidly with norepinephrine compared with vasopressin, although differences between study arms did not persist after day 4. Joint models are an accessible methodology that could be used in critical care trials to assess the effects of interventions on the longitudinal progression of key outcomes (e.g., organ dysfunction, biomarkers, or quality of life) that may be informatively truncated by death or other censoring events.
Project description:Vasopressin is widely used for vasopressor support in septic shock patients, but experimental evidence suggests that selective V1A agonists are superior. The initial pharmacodynamic effects, pharmacokinetics, and safety of selepressin, a novel V1A-selective vasopressin analogue, was examined in a phase IIa trial in septic shock patients.This was a randomized, double-blind, placebo-controlled multicenter trial in 53 patients in early septic shock (aged ?18 years, fluid resuscitation, requiring vasopressor support) who received selepressin 1.25 ng/kg/minute (n?=?10), 2.5 ng/kg/minute (n?=?19), 3.75 ng/kg/minute (n?=?2), or placebo (n?=?21) until shock resolution or a maximum of 7 days. If mean arterial pressure (MAP) ?65 mmHg was not maintained, open-label norepinephrine was added. Co-primary endpoints were maintenance of MAP >60 mmHg without norepinephrine, norepinephrine dose, and proportion of patients maintaining MAP >60 mmHg with or without norepinephrine over 7 days. Secondary endpoints included cumulative fluid balance, organ dysfunction, pharmacokinetics, and safety.A higher proportion of the patients receiving 2.5 ng/kg/minute selepressin maintained MAP >60 mmHg without norepinephrine (about 50% and 70% at 12 and 24 h, respectively) vs. 1.25 ng/kg/minute selepressin and placebo (p?<?0.01). The 7-day cumulative doses of norepinephrine were 761, 659, and 249 ?g/kg (placebo 1.25 ng/kg/minute and 2.5 ng/kg/minute, respectively; 2.5 ng/kg/minute vs. placebo; p?<?0.01). Norepinephrine infusion was weaned more rapidly in selepressin 2.5 ng/kg/minute vs. placebo (0.04 vs. 0.18 ?g/kg/minute at 24 h, p?<?0.001), successfully maintaining target MAP and reducing norepinephrine dose vs. placebo (first 24 h, p?<?0.001). Cumulative net fluid balance was lower from day 5 onward in the selepressin 2.5 ng/kg/minute group vs. placebo (p?<?0.05). The selepressin 2.5 ng/kg/minute group had a greater proportion of days alive and free of ventilation vs. placebo (p?<?0.02). Selepressin (2.5 ng/kg/minute) was well tolerated, with a similar frequency of treatment-emergent adverse events for selepressin 2.5 ng/kg/minute and placebo. Two patients were infused at 3.75 ng/kg/minute, one of whom had the study drug infusion discontinued for possible safety reasons, with subsequent discontinuation of this dose group.In septic shock patients, selepressin 2.5 ng/kg/minute was able to rapidly replace norepinephrine while maintaining adequate MAP, and it may improve fluid balance and shorten the time of mechanical ventilation.ClinicalTrials.gov, NCT01000649 . Registered on September 30, 2009.
Project description:Patients with distributive shock who require high dose vasopressors have a high mortality. Angiotensin II (ATII) may prove useful in patients who remain hypotensive despite catecholamine and vasopressin therapy. The appropriate dose of parenteral angiotensin II for shock is unknown.In total, 20 patients with distributive shock and a cardiovascular Sequential Organ Failure Assessment score of 4 were randomized to either ATII infusion (N =10) or placebo (N =10) plus standard of care. ATII was started at a dose of 20 ng/kg/min, and titrated for a goal of maintaining a mean arterial pressure (MAP) of 65 mmHg. The infusion (either ATII or placebo) was continued for 6 hours then titrated off. The primary endpoint was the effect of ATII on the standing dose of norepinephrine required to maintain a MAP of 65 mmHg.ATII resulted in marked reduction in norepinephrine dosing in all patients. The mean hour 1 norepinephrine dose for the placebo cohort was 27.6?±?29.3 mcg/min versus 7.4?±?12.4 mcg/min for the ATII cohort (P =0.06). The most common adverse event attributable to ATII was hypertension, which occurred in 20% of patients receiving ATII. 30-day mortality for the ATII cohort and the placebo cohort was similar (50% versus 60%, P =1.00).Angiotensin II is an effective rescue vasopressor agent in patients with distributive shock requiring multiple vasopressors. The initial dose range of ATII that appears to be appropriate for patients with distributive shock is 2 to 10 ng/kg/min.Clinicaltrials.gov NCT01393782. Registered 12 July 2011.
Project description:The Surviving Sepsis Guidelines suggest the use of vasopressin in case of catecholamine-refractory septic shock. Terlipressin (TP) as a V1-selective AVP analogue is a potential alternative, though data regarding the first-line administration in septic shock are scarce. The present study explored and compared the effects of first-line vs. second-line infusion of TP or sole norepinephrine regarding organ function, fluid and norepinephrine requirements and survival in fulminant ovine septic shock. Peritoneal sepsis was induced in 23 ewes after laparotomy and faecal withdrawal from the caecum. After onset of shock, causal and supportive sepsis therapy (antibiotics, peritoneal lavage, fluids and open-label norepinephrine) was performed in all animals. Concurrently, animals were randomized to receive 0.9% sodium chloride (control group) or TP (2?µg?kg-1?h-1, first-line group) after shock onset. In the second-line TP group, TP (2?µg?kg-1?h-1) was started once norepinephrine requirements exceeded 0.5?µg?kg-1?min-1. No significant differences were found between groups regarding survival, haemodynamics as well as fluid- and catecholamine-requirements. Kidney function and electron microscopic kidney injury were comparable between groups. In the present model of fulminant ovine septic shock, first-line TP infusion had no significant effect on fluid and norepinephrine requirements or organ dysfunction as compared to second-line TP infusion or placebo.
Project description:OBJECTIVE:International guidelines recommend dopamine or norepinephrine as first-line vasopressor agents in septic shock. Phenylephrine, epinephrine, vasopressin and terlipressin are considered second-line agents. Our objective was to assess the evidence for the efficiency and safety of all vasopressors in septic shock. METHODS:Systematic review and meta-analysis. We searched electronic database of MEDLINE, CENTRAL, LILACS and conference proceedings up to June 2014. We included randomized controlled trials comparing different vasopressors for the treatment of adult patients with septic shock. Primary outcome was all-cause mortality. Other clinical and hemodynamic measurements were extracted as secondary outcomes. Risk ratios (RR) and mean differences with 95% confidence intervals (CI) were pooled. RESULTS:Thirty-two trials (3,544 patients) were included. Compared to dopamine (866 patients, 450 events), norepinephrine (832 patients, 376 events) was associated with decreased all-cause mortality, RR 0.89 (95% CI 0.81-0.98), corresponding to an absolute risk reduction of 11% and number needed to treat of 9. Norepinephrine was associated with lower risk for major adverse events and cardiac arrhythmias compared to dopamine. No other mortality benefit was demonstrated for the comparisons of norepinephrine to epinephrine, phenylephrine and vasopressin / terlipressin. Hemodynamic data were similar between the different vasopressors, with some advantage for norepinephrine in central venous pressure, urinary output and blood lactate levels. CONCLUSIONS:Evidence suggests a survival benefit, better hemodynamic profile and reduced adverse events rate for norepinephrine over dopamine. Norepinephrine should be regarded as the first line vasopressor in the treatment of septic shock.