Pharmacologic support of the failing circulation: practice, education, evidence, and future directions

Vasopressors in septic shock: a systematic review and network meta-analysis

Objective

Vasopressor agents are often prescribed in septic shock. However, their effects remain controversial. We conducted a systematic review and Bayesian network meta-analysis to compare the effects among different types of vasopressor agents.

Data sources

We searched for relevant studies in PubMed, Embase, and the Cochrane Library databases from database inception until December 2014.

Study selection

Randomized controlled trials in adults with septic shock that evaluated different vasopressor agents were selected.

Data extraction

Two authors independently selected studies and extracted data on study characteristics, methods, and outcomes.

Data synthesis

Twenty-one trials (n=3,819) met inclusion criteria, which compared eleven vasopressor agents or vasopressor combinations (norepinephrine [NE], dopamine [DA], vasopressin [VP], epinephrine [EN], terlipressin [TP], phenylephrine [PE], TP+NE, TP + dobutamine [DB], NE+DB, NE+EN, and NE + dopexamine [DX]). Except for the superiority of NE over DA, the mortality of patients treated with any vasopressor agent or vasopressor combination was not significantly different. Compared to DA, NE was found to be associated with decreased cardiac adverse events, heart rate (standardized mean difference [SMD]: −2.10; 95% confidence interval [CI]: −3.95, −0.25; P=0.03), and cardiac index (SMD: −0.73; 95% CI: −1.14, −0.03; P=0.004) and increased systemic vascular resistance index (SVRI) (SMD: 1.03; 95% CI: 0.61, 1.45; P<0.0001). This Bayesian meta-analysis revealed a possible rank of probability of mortality among the eleven vasopressor agents or vasopressor combinations; from lowest to highest, they are NE+DB, EN, TP, NE+EN, TP+NE, VP, TP+DB, NE, PE, NE+DX, and DA.

Conclusion

In terms of survival, NE may be superior to DA. Otherwise, there is insufficient evidence to suggest that any other vasopressor agent or vasopressor combination is superior to another. When compared to DA, NE is associated with decreased heart rate, cardiac index, and cardiovascular adverse events, as well as increased SVRI. The effects of vasopressor agents or vasopressor combinations on mortality in patients with septic shock require further investigation.

Adrenergic support in septic shock: a critical review

The definition of septic shock includes sepsis-induced hypotension despite adequate fluid resuscitation, along with the presence of organ perfusion abnormalities, and ultimately cell dysfunction. To restore adequate organ perfusion and cell homeostasis, cardiac output should be restored with volume infusion plus vasopressor agents as indicated. Appropriate arterial pressure for each individual patient and proper arterial oxygen content are key elements to restoring perfusion. Tissue perfusion can be monitored by markers of organ and mitochondrial function, namely urine output, level of consciousness, peripheral skin perfusion, central or mixed venous oxygen saturation, and lactate. The hemodynamic effects of the different vasopressor agents depend on the relative affinity to adrenergic receptors. Those with predominant alpha-agonist activity produce more vasoconstriction (inoconstrictors) while those with predominant beta-agonist stimulation increase cardiac performance (inodilators). The debate about whether one vasopressor agent is superior to another is still ongoing. The Surviving Sepsis Campaign guidelines refer to either norepinephrine or dopamine as the first-choice vasopressor agent to correct hypotension in septic shock. However, recent data from observational and controlled trials have challenged these recommendations concerning different adrenergic agents. As a result, our view on the prescription of vasopressors has changed from a probably oversimplified "one-size-fits-all" approach to a multimodal approach in vasopressor selection.

Influence of vasopressor agent in septic shock mortality. Results from the Portuguese Community-Acquired Sepsis Study (SACiUCI study)

OBJECTIVE

Guidelines for the adrenergic support of septic shock are controversial. In patients with community-acquired septic shock, we assessed the impact of the choice of vasopressor support on mortality.

DESIGN

Cohort, multiple center, observational study.

SETTING

Seventeen Portuguese intensive care units (ICUs).

PATIENTS

All adult patients admitted to a participating ICU between December 2004 and November 2005.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients were followed up during the first five ICU days, the day of discharge or death, and hospital outcome. Eight hundred ninety-seven consecutive patients with community-acquired sepsis (median age, 63 years; 577 men; and hospital mortality, 38%) were studied. Of the 458 patients with septic shock, 73% received norepinephrine and 50.5% dopamine. The norepinephrine group had a higher hospital mortality (52% vs. 38.5%, p = 0.002). A Kaplan-Meier survival curve showed diminished 28-day survival in the norepinephrine group (log-rank = 22.6, p < 0.001). A Cox proportional hazard analysis revealed that the administration of norepinephrine was associated with an increased risk of death (adjusted hazard ratio, 2.501; 95% confidence interval, 1.413-4.425; p = 0.002). In a multivariate analysis with ICU mortality as the dependent factor, Simplified Acute Physiology Score II and norepinephrine administration were independent risk factors for ICU mortality in patients with septic shock.

CONCLUSIONS

In patients with community-acquired septic shock, our data suggest that norepinephrine administration could be associated with worse outcome.

[Is there still a place for dopamine in the paediatric critical care setting?]

Dopamine is mostly used in patients with cardiogenic or septic shock, but its place in critical care medicine is often questioned. Dopamine, of which pharmacology in children is variable, is prescribed for its inotropic effect, associated with an increase in cardiac output and at a lesser degree blood pressure. Beneficial effects (need for renal replacement therapy and mortality) of low dose in patients at risk of, or with acute renal failure are not demonstrated. Dopamine has numerous potential deleterious effects on local circulations (pulmonary, cerebral, coronary and cutaneous), respiratory function, gastroduodenal motility, endocrine function (further depression of the hypothalamic-pituitary axis induced by stress) and immunity (partially due to decreased production of prolactin). Finally, in shocked adults dopamine infusion might be associated with an increase in mortality rate. Dopamine remains the most prescribed catecholamine, either in adults or children. It still is one of the first line drug included in the recent recommendations for the treatment of septic shock (norepinephrine tends to replace it), cardiogenic shock (dobutamine is the first drug), severe head trauma, and organ donor in cerebral death. In conclusion, if dopamine is today less used, there is no proof that its deleterious effects are associated with an excess of mortality. Thus, dopamine still is part of the stock of drugs that act on the cardiocirculatory system (but for how long?).