Early versus delayed administration of norepinephrine in patients with septic shock

From a pressure-guided to a perfusion-centered resuscitation strategy in septic shock: Critical literature review and illustrative case

PURPOSE

To support a paradigm shift in the management of septic shock from pressure-guided to perfusion-centered, expected to improve outcome while reducing adverse effects from vasopressor therapy and aggressive fluid resuscitation.

MATERIAL AND METHODS

Critical review of the literature cited in support of vasopressor use to achieve a predefined mean arterial pressure (MAP) of 65 mmHg and review of pertinent clinical trials and studies enabling deeper understanding of the hemodynamic pathophysiology supportive of a perfusion-centered approach, accompanied by an illustrative case.

RESULTS

Review of the literature cited by the Surviving Sepsis Campaign revealed lack of controlled clinical trials supporting outcome benefits from vasopressors. Additional literature review revealed adverse effects associated with vasopressors and worsened outcome in some studies. Vasopressors increase MAP primarily by peripheral vasoconstriction and in occasions by a modest increase in cardiac output when using norepinephrine. Thus, achieving the recommended MAP of 65 mmHg using vasopressors should not be presumed indicative that organ perfusion has been restored. It may instead create a false sense of hemodynamic stability hampering shock resolution.

CONCLUSIONS

We propose focusing the hemodynamic management of septic shock on reversing organ hypoperfusion instead of attaining a predefined MAP target as the key strategy for improving outcome.

Early lactate measurement is associated with better outcomes in septic patients with an elevated serum lactate level

Background

The optimal timing of lactate measurement for septic patients in the intensive care unit (ICU) remains controversial, and whether initiating and repeating the lactate measurement earlier could make a difference for septic patients with an elevated lactate level remains unexplored.

Methods

This was a retrospective observational study that included septic patients with an initial lactate level > 2.0 mmol/L after ICU admission, and all data were extracted from the Medical Information Mart for Intensive Care III (MIMIC-III) database. The main exposure of interest was the early lactate measurement, which was defined as an initial lactate level measurement within 1 h after ICU admission. The primary outcome was 28-day mortality.

Results

A total of 2642 eligible subjects were enrolled, including 738 patients who had initial lactate measurements completed within 1 h (EL group) and 1904 patients who had initial lactate measurements completed more than 1 h after ICU admission (LL group). A significant beneficial effect of early lactate measurement in terms of 28-day mortality was observed: the adjusted odds ratio (OR) was 0.69 (95% CI 0.55–0.87; p = 0.001), and the mediation effect of the time to initial vasopressor administration was significant (average causal mediation effect (ACME) − 0.018; 95% CI − 0.005 approximately to − 0.036; p < 0.001). A strong relationship between delayed initial lactate measurement and risk-adjusted 28-day mortality was noted (OR 1.04; 95% CI 1.02–1.05; p < 0.001). Each hour of delay in remeasuring the lactate level was associated with an increase in 28-day mortality in the EL group (OR 1.09; 95% CI 1.04–1.15; p < 0.001). Further analysis demonstrated that repeating the measurement 3 h after the initial lactate measurement led to a significant difference.

Conclusions

Early lactate measurement is associated with a lower risk-adjusted 28-day mortality rate in septic patients with lactate levels > 2.0 mmol/L. A shorter time to the initial vasopressor administration may contribute to this relationship. Repeating the lactate measurement within 3 h after the initial measurement is appropriate for patients whose lactate levels were measured within 1 h of admission.

Delayed vasopressor initiation is associated with increased mortality in patients with septic shock

PURPOSE

Mortality rate for septic shock, despite advancements in knowledge and treatment, remains high. Treatment includes administration of broad-spectrum antibiotics and stabilization of the mean arterial pressure (MAP) with intravenous fluid resuscitation. Fluid-refractory shock warrants vasopressor initiation. There is a paucity of evidence regarding the timing of vasopressor initiation and its effect on patient outcomes.

MATERIALS AND METHODS

This retrospective, single-centered, cohort study included patients with septic shock from January 2017 to July 2017. Time from initial hypotension to vasopressor initiation was measured for each patient. The primary outcome was 30-day mortality.

RESULTS

Of 530 patients screened,119 patients were included. There were no differences in baseline patient characteristics. Thirty-day mortality was higher in patients who received vasopressors after 6 h (51.1% vs 25%, p < .01). Patients who received vasopressors within the first 6 h had more vasopressor-free hours at 72 h (34.5 h vs 13.1, p = .03) and shorter time to MAP of 65 mmHg (1.5 h vs 3.0, p < .01).

CONCLUSION

Vasopressor initiation after 6 h from shock recognition is associated with a significant increase in 30-day mortality. Vasopressor administration within 6 h was associated with shorter time to achievement of MAP goals and higher vasopressor-free hours within the first 72 h.

Early Use of Norepinephrine Improves Survival in Septic Shock: Earlier than Early

BACKGROUND

The timing of initiation of Norepinephrine (NEP) in septic shock is controversial.

AIM OF THE STUDY

We evaluated the impact of early NEP simultaneously with fluids in those patients.

METHODS

We randomized 101 patients admitted to the emergency department with septic shock to early NEP simultaneously with IV fluids (early group) or after failed fluids trial (late group). The primary outcome was the in-hospital survival while the secondary outcomes were the time to target mean arterial pressure (MAP) of 65 mmHg, lactate clearance and resuscitation volumes.

RESULTS

There was no significant difference between the two groups regarding the baseline characteristics. NEP infusion started after 25 (20-30) and 120 (120-180) min in the early and late groups (p = 0.000). MAP of 65 mmHg was achieved faster in the early group (2 [1-3.5] h vs. 3 [2-4.75] h, p = 0.003). Serum lactate was decreased by 37.8 (24-49%) and 22.2 (3.3-38%) in both groups respectively (p = 0.005). Patients with early NEP were resuscitated by significantly lower volume of fluids (25 [18.8-28.7] mL/kg vs. 32.5 [24.4-34.6] mL/kg) in the early and late groups (p = 0.000). The early group had survival rate of 71.9% compared to 45.5% in the late group (p = 0.007). NEP started after 30 (20-120 min) in survivors vs. 120 (30-165 min) in non-survivors (p = 0.013).

CONCLUSIONS

We concluded that early Norepinephrine in septic shock might cause earlier restoration of blood pressure, better lactate clearance and improve in-hospital survival.

Optimal norepinephrine-equivalent dose to initiate epinephrine in patients with septic shock

PURPOSE

The specific norepinephrine dose at which epinephrine should be added in septic shock is unclear. This study sought to determine the norepinephrine-equivalent dose at epinephrine initiation that correlated with hemodynamic stability.

METHODS

Septic shock patients receiving both norepinephrine and epinephrine were included in this study. Classification and regression tree analysis was conducted to determine breakpoints in norepinephrine-equivalent dose predicting hemodynamic stability, with two cohorts identified. The primary outcome was hemodynamic stability, and secondary outcomes were shock-free survival, time to achieve hemodynamic stability, and change in SOFA score.

RESULTS

Optimal dose group was identified as initiating epinephrine when norepinephrine-equivalent dose was between 37 and 133 μg/min. A total of 138 and 61 patients were classified in optimal and non-optimal dose groups, respectively. Baseline characteristics were similar between groups except vasopressin use was more frequent in the optimal dose group. More patients in optimal dose group versus non-optimal dose group achieved hemodynamic stability (40 [29%] vs. 9 [14.8%]), absolute risk difference 14.2% [95% CI 2.5-25.9%]; p = .03). On multivariable analysis, initiating epinephrine within the optimal norepinephrine-equivalent dose range was independently associated with higher odds of hemodynamic response (OR 3.06 [95% CI 1.2-7.6]; p = .02). No differences were observed in other secondary outcomes.

CONCLUSIONS

Initiation of epinephrine when patients were receiving norepinephrine-equivalent doses of 37-133 μg/min was associated with a higher rate of hemodynamic stability.

Intra-Abdominal Hypertension Is More Common Than Previously Thought: A Prospective Study in a Mixed Medical-Surgical ICU

OBJECTIVES

To determine the prevalence of intra-abdominal hypertension in mixed medical-surgical critically ill patients using modern definitions and measurement techniques. Secondarily to determine variables associated with intra-abdominal hypertension and ICU mortality.

DESIGN

A prospective observational study.

SETTING

Single institution trauma, medical and surgical ICU in Canada.

PATIENTS

Consecutive adult patients admitted to the ICU (n = 285).

INTERVENTION

Intra-abdominal pressure measurements twice a day during admission to the ICU.

MEASUREMENTS AND MAIN RESULTS

In 285 patients who met inclusion criteria, 30% were diagnosed with intra-abdominal hypertension at admission and a further 15% developed intra-abdominal hypertension during admission. The prevalence of abdominal compartment syndrome was 3%. Obesity, sepsis, mechanical ventilation, and 24-hour fluid balance (> 3 L) were all independent predictors for intra-abdominal hypertension. Intra-abdominal hypertension occurred in 28% of nonventilated patients. Admission type (medical vs surgical vs trauma) was not a significant predictor of intra-abdominal hypertension. Overall ICU mortality was 20% and was significantly higher for patients with intra-abdominal hypertension (30%) compared with patients without intra-abdominal hypertension (11%). Intra-abdominal hypertension of any grade was an independent predictor of mortality (odds ratio, 3.33; 95% CI, 1.46-7.57).

CONCLUSIONS

Intra-abdominal hypertension is common in both surgical and nonsurgical patients in the intensive care setting and was found to be independently associated with mortality. Despite prior reports to the contrary, intra-abdominal hypertension develops in nonventilated patients and in patients who do not have intra-abdominal hypertension at admission. Intra-abdominal pressure monitoring is inexpensive, provides valuable clinical information, and there may be a role for its routine measurement in the ICU. Future work should evaluate the impact of early interventions for patients with intra-abdominal hypertension.

Fournier Gangrene: A Review for Emergency Clinicians

BACKGROUND

Fournier gangrene (FG) is a rare, life-threatening infection that can result in significant morbidity and mortality, with many patients requiring emergency department (ED) management for complications and stabilization.

OBJECTIVE

This narrative review provides an evidence-based summary of the current data for the emergency medicine evaluation and management of FG.

DISCUSSION

Although originally thought to be an idiopathic process, FG has been shown to have a strong association for male patients with advanced age and comorbidities affecting microvascular circulation and immune system function, most commonly those with diabetes or alcohol use disorder. However, it can also affect patients without risk factors. The initial infectious nidus is usually located in the genitourinary tract, gastrointestinal tract, or perineum. FG is a mixed infection of aerobic and anaerobic bacterial flora. The development and progression of gangrene is often fulminant and can rapidly cause multiple organ failure and death, although patients may present subacutely with findings similar to cellulitis. Laboratory studies, as well as imaging including point-of-care ultrasound, conventional radiography, and computed tomography are important diagnostic adjuncts, though negative results cannot exclude diagnosis. Treatment includes emergent surgical debridement of all necrotic tissue, broad-spectrum antibiotics, and resuscitation with intravenous fluids and vasoactive medications.

CONCLUSIONS

FG requires a high clinical level of suspicion, combined with knowledge of anatomy, risk factors, and etiology for an accurate diagnosis. Although FG remains a clinical diagnosis, relevant laboratory and radiography investigations can serve as useful adjuncts to expedite surgical management, hemodynamic resuscitation, and antibiotic administration.

Biotechnological Advances in Resveratrol Production and its Chemical Diversity

The very well-known bioactive natural product, resveratrol (3,5,4'-trihydroxystilbene), is a highly studied secondary metabolite produced by several plants, particularly grapes, passion fruit, white tea, and berries. It is in high demand not only because of its wide range of biological activities against various kinds of cardiovascular and nerve-related diseases, but also as important ingredients in pharmaceuticals and nutritional supplements. Due to its very low content in plants, multi-step isolation and purification processes, and environmental and chemical hazards issues, resveratrol extraction from plants is difficult, time consuming, impracticable, and unsustainable. Therefore, microbial hosts, such as Escherichia coli, Saccharomyces cerevisiae, and Corynebacterium glutamicum, are commonly used as an alternative production source by improvising resveratrol biosynthetic genes in them. The biosynthesis genes are rewired applying combinatorial biosynthetic systems, including metabolic engineering and synthetic biology, while optimizing the various production processes. The native biosynthesis of resveratrol is not present in microbes, which are easy to manipulate genetically, so the use of microbial hosts is increasing these days. This review will mainly focus on the recent biotechnological advances for the production of resveratrol, including the various strategies used to produce its chemically diverse derivatives.

Minimizing catecholamines and optimizing perfusion

Catecholamines are used to increase cardiac output and blood pressure, aiming ultimately at restoring/improving tissue perfusion. While intuitive in its concept, this approach nevertheless implies to be effective that regional organ perfusion would increase in parallel to cardiac output or perfusion pressure and that the catecholamine does not have negative effects on the microcirculation. Inotropic agents may be considered in some conditions, but it requires prior optimization of cardiac preload. Alternative approaches would be either to minimize exposure to vasopressors, tolerating hypotension and trying to prioritize perfusion but this may be valid as long as perfusion of the organ is preserved, or to combine moderate doses of vasopressors to vasodilatory agents, especially if these are predominantly acting on the microcirculation. In this review, we will discuss the pros and cons of the use of catecholamines and alternative agents for improving tissue perfusion in septic shock.

Septic shock in the ER: diagnostic and management challenges

Sepsis is a common presentation in the emergency department and a common cause of intensive care unit admissions and death. Accurate triage, rapid recognition, early resuscitation, early antibiotics, and eradication of the source of infection are the key components in delivering quality sepsis care. Evaluation of the patient's volume status, optimal hemodynamic resuscitation, and evaluation of patient response is crucial for sepsis management in the emergency department.

Beyond Mean Arterial Pressure and Lactate: Perfusion End Points for Managing the Shocked Patient

Patients in shock present frequently to the emergency department. The emergency physician must be skilled in the resuscitation of both differentiated and undifferentiated shock. Early, aggressive resuscitation of patients in shock is essential, using macrocirculatory, microcirculatory, and clinical end points to guide interventions. Therapy should focus on the restoration of oxygen delivery to match tissue demand. This article reviews the evidence supporting common end points of resuscitation for common etiologies of shock and limitations to their use.

Successful management of persistent tachycardia using esmolol in 2 dogs with septic shock

OBJECTIVE

To describe the successful management of 2 dogs with septic shock and persistent tachycardia using norepinephrine and esmolol, a short-acting beta receptor antagonist.

SERIES SUMMARY

Two cases are reviewed. In the first case, septic shock with ventricular tachycardia was diagnosed in a 4-year-old neutered female Great Dane that underwent jejunoileal resection and anastomosis for a partial mesenteric torsion. The patient's tachyarrhythmias failed to respond to lidocaine, and an esmolol infusion was used for heart rate control. The condition of the dog improved and she was discharged after 4 days of hospitalization. The second case was a 7-year-old neutered female Cavalier King Charles Spaniel with septic peritonitis. Following surgery for intestinal resection and anastomosis, supraventricular tachycardia developed that was not responsive to volume resuscitation and was treated with an esmolol infusion. The condition of the dog improved and she was discharged after 6 days of hospitalization. Both patients were doing well at the time of long-term follow-up.

NEW OR UNIQUE INFORMATION PROVIDED

This case series highlights a novel method of managing dogs in septic shock with persistent tachycardia based on recently published data in the human literature. The use of esmolol may be considered in certain veterinary patients with septic shock to improve persistent tachycardia not related to hypovolemia.

Norepinephrine and Vasopressin Compared With Norepinephrine and Epinephrine in Adults With Septic Shock

Background: The optimal adjuvant vasopressor to norepinephrine in septic shock remains controversial. Objective: To compare durations of shock-free survival between adjuvant vasopressin and epinephrine. Methods: A retrospective, single-center, matched cohort study of adults with septic shock refractory to norepinephrine was conducted. Patients receiving norepinephrine not at target mean arterial pressure (MAP; 65 mm Hg) were initiated on vasopressin or epinephrine to raise MAP to target. Vasopressin-exposed patients were matched to epinephrine-exposed patients using propensity scores. Mortality outcomes were examined using multivariable Poisson regression with robust variance estimation. Results: Of 166 patients, 96 (entire cohort) were included in the propensity score-matched cohort. Shock-free survival durations in the first 7 days were similar between epinephrine- and vasopressin-exposed patients in the matched cohort (median = 13.2 hours, interquartile range [IQR] = 0-121.0, vs median = 41.3 hours, IQR = 0-125.9; P = 0.51). Seven- and 28-day mortality rates were similar in the matched cohort (7-day: 47.9% vs 39.6%, P = 0.35; 28-day: 56.3% vs 58.3%, P = 0.84). Mortality rates were similar between epinephrine- and vasopressin-exposed patients in propensity score-matched regression models with and without adjustments at 7 (relative risk [RR] = 1.28, 95% CI = 0.92-1.79; RR = 1.21, 95% CI = 0.81-1.81) and 28 days (RR = 1.04, 95% CI = 0.81-1.34; RR = 0.96, 95% CI = 0.69-1.34). Conclusion and Relevance: Shock-free survival durations were similar in matched epinephrine- and vasopressin-exposed groups. Adjuvant epinephrine or vasopressin alongside norepinephrine to raise MAP to target requires further investigation.

Physician agreement on the diagnosis of sepsis in the intensive care unit: estimation of concordance and analysis of underlying factors in a multicenter cohort

Background

Differentiating sepsis from the systemic inflammatory response syndrome (SIRS) in critical care patients is challenging, especially before serious organ damage is evident, and with variable clinical presentations of patients and variable training and experience of attending physicians. Our objective was to describe and quantify physician agreement in diagnosing SIRS or sepsis in critical care patients as a function of available clinical information, infection site, and hospital setting.

Methods

We conducted a post hoc analysis of previously collected data from a prospective, observational trial (N = 249 subjects) in intensive care units at seven US hospitals, in which physicians at different stages of patient care were asked to make diagnostic calls of either SIRS, sepsis, or indeterminate, based on varying amounts of available clinical information (clinicaltrials.gov identifier: NCT02127502). The overall percent agreement and the free-marginal, inter-observer agreement statistic kappa (κ_free) were used to quantify agreement between evaluators (attending physicians, site investigators, external expert panelists). Logistic regression and machine learning techniques were used to search for significant variables that could explain heterogeneity within the indeterminate and SIRS patient subgroups.

Results

Free-marginal kappa decreased between the initial impression of the attending physician and (1) the initial impression of the site investigator (κ_free 0.68), (2) the consensus discharge diagnosis of the site investigators (κ_free 0.62), and (3) the consensus diagnosis of the external expert panel (κ_free 0.58). In contrast, agreement was greatest between the consensus discharge impression of site investigators and the consensus diagnosis of the external expert panel (κ_free 0.79). When stratified by infection site, κ_free for agreement between initial and later diagnoses had a mean value + 0.24 (range − 0.29 to + 0.39) for respiratory infections, compared to + 0.70 (range + 0.42 to + 0.88) for abdominal + urinary + other infections. Bioinformatics analysis failed to clearly resolve the indeterminate diagnoses and also failed to explain why 60% of SIRS patients were treated with antibiotics.

Conclusions

Considerable uncertainty surrounds the differential clinical diagnosis of sepsis vs. SIRS, especially before organ damage has become highly evident, and for patients presenting with respiratory clinical signs. Our findings underscore the need to provide physicians with accurate, timely diagnostic information in evaluating possible sepsis.

Electronic supplementary material

The online version of this article (10.1186/s40560-019-0368-2) contains supplementary material, which is available to authorized users.

Current use of vasopressors in septic shock

Background

Vasopressors are commonly applied to restore and maintain blood pressure in patients with sepsis. We aimed to evaluate the current practice and therapeutic goals regarding vasopressor use in septic shock as a basis for future studies and to provide some recommendations on their use.

Methods

From November 2016 to April 2017, an anonymous web-based survey on the use of vasoactive drugs was accessible to members of the European Society of Intensive Care Medicine (ESICM). A total of 17 questions focused on the profile of respondents, triggering factors, first choice agent, dosing, timing, targets, additional treatments, and effects of vasopressors. We investigated whether the answers complied with current guidelines. In addition, a group of 34 international ESICM experts was asked to formulate recommendations for the use of vasopressors based on 6 questions with sub-questions (total 14).

Results

A total of 839 physicians from 82 countries (65% main specialty/activity intensive care) responded. The main trigger for vasopressor use was an insufficient mean arterial pressure (MAP) response to initial fluid resuscitation (83%). The first-line vasopressor was norepinephrine (97%), targeting predominantly a MAP > 60–65 mmHg (70%), with higher targets in patients with chronic arterial hypertension (79%). The experts agreed on 10 recommendations, 9 of which were based on unanimous or strong (≥ 80%) agreement. They recommended not to delay vasopressor treatment until fluid resuscitation is completed but rather to start with norepinephrine early to achieve a target MAP of ≥ 65 mmHg.

Conclusion

Reported vasopressor use in septic shock is compliant with contemporary guidelines. Future studies should focus on individualized treatment targets including earlier use of vasopressors.

Pulse Pressure and Mortality Risk in Critically Ill Patients

BACKGROUND

Pulse pressure is a hemodynamic variable easily measured in the intensive care unit.

OBJECTIVE

To investigate whether pulse pressure is an independent risk factor for mortality in intensive care unit patients.

METHODS

A retrospective cohort study was carried out in Brazil. Data were collected from medical records of patients admitted to intensive care units from September to December 2012. Pulse pressure was calculated from systolic and diastolic blood pressures recorded during the first 24 hours of stay.

RESULTS

Records of 529 patients (mean [standard deviation] age 55.0 [17.3] years; 54.4% male, 45.6% female) were analyzed. Risk factors for mortality were age, use of vasoactive drugs, nursing workload, and length of stay in the intensive care unit. Analysis indicated that higher minimum pulse pressures were associated with lower mortality risk.

CONCLUSION

Pulse pressure was not found to be an independent risk factor for mortality in patients who are critically ill.

Abdominal organ perfusion and inflammation in experimental sepsis: a magnetic resonance imaging study

Diffusion-weighted magnetic resonance imaging (DW-MRI) uses water as contrast and enables the study of perfusion in many organs simultaneously in situ. We used DW-MRI in a hypodynamic sepsis model, comparing abdominal organ perfusion with global hemodynamic measurements and inflammation. Sixteen anesthetized piglets were randomized into 3 groups: 2 intervention (sepsis) groups: HighMAP (mean arterial pressure, MAP > 65 mmHg) and LowMAP (MAP between 50 and 60 mmHg), and a Healthy Control group (HC). Sepsis was obtained with endotoxin and the desired MAP maintained with norepinephrine. After 6 h, DW-MRI was performed. Acute inflammation was assessed with IL-6 and TNFα in abdominal organs, ascites, and blood and by histology of intestine (duodenum). Perfusion of abdominal organs was reduced in the LowMAP group compared with the HighMAP group and HC. Liver perfusion was still reduced by 25% in the HighMAP group compared with HC. Intestinal perfusion did not differ significantly between the intervention groups. Cytokine concentrations were generally higher in the LowMAP group but did not correlate with global hemodynamics. However, cytokines correlated with regional perfusion and, for liver and intestine, also with intra-abdominal pressure. Histopathology of intestine worsened with decreasing perfusion. In conclusion, although a low MAP (≤60 mmHg) indicated impeded abdominal perfusion in experimental sepsis, it did not predict inflammation, nor did other global measures of circulation. Decreased abdominal perfusion partially predicted inflammation but intestine, occupying most of the abdomen, and liver were also affected by intra-abdominal pressure. NEW & NOTEWORTHY The study increases the knowledge of abdominal perfusion during sepsis. We used diffusion weighted imaging to assess perfusion simultaneously and noninvasively in different abdominal organs. The technique has not been used in a sepsis model before. Cytokine concentrations were measured in different abdominal organs and vascular beds and related to regional perfusion. Decreased abdominal perfusion, but not global measures of circulation, predicted inflammation. Intestine, occupying most of the abdomen, and liver were also affected by intra-abdominal pressure.

Hemodynamic support in the early phase of septic shock: a review of challenges and unanswered questions

Background

Improving sepsis support is one of the three pillars of a 2017 resolution according to the World Health Organization (WHO). Septic shock is indeed a burden issue in the intensive care units. Hemodynamic stabilization is a cornerstone element in the bundle of supportive treatments recommended in the Surviving Sepsis Campaign (SSC) consecutive biannual reports.

Main body

The “Pandera’s box” of septic shock hemodynamics is an eternal debate, however, with permanent contentious issues. Fluid resuscitation is a prerequisite intervention for sepsis rescue, but selection, modalities, dosage as well as duration are subject to discussion while too much fluid is associated with worsen outcome, vasopressors often need to be early introduced in addition, and catecholamines have long been recommended first in the management of septic shock. However, not all patients respond positively and controversy surrounding the efficacy-to-safety profile of catecholamines has come out. Preservation of the macrocirculation through a “best” mean arterial pressure target is the actual priority but is still contentious. Microcirculation recruitment is a novel goal to be achieved but is claiming more knowledge and monitoring standardization. Protection of the cardio-renal axis, which is prevalently injured during septic shock, is also an unavoidable objective. Several promising alternative or additive drug supporting avenues are emerging, trending toward catecholamine’s sparing or even “decatecholaminization.” Topics to be specifically addressed in this review are: (1) mean arterial pressure targeting, (2) fluid resuscitation, and (3) hemodynamic drug support.

Conclusion

Improving assessment and means for rescuing hemodynamics in early septic shock is still a work in progress. Indeed, the bigger the unresolved questions, the lower the quality of evidence.

The Artificial Intelligence Clinician learns optimal treatment strategies for sepsis in intensive care

Sepsis is the third leading cause of death worldwide and the main cause of mortality in hospitals^1-3, but the best treatment strategy remains uncertain. In particular, evidence suggests that current practices in the administration of intravenous fluids and vasopressors are suboptimal and likely induce harm in a proportion of patients^1,4-6. To tackle this sequential decision-making problem, we developed a reinforcement learning agent, the Artificial Intelligence (AI) Clinician, which extracted implicit knowledge from an amount of patient data that exceeds by many-fold the life-time experience of human clinicians and learned optimal treatment by analyzing a myriad of (mostly suboptimal) treatment decisions. We demonstrate that the value of the AI Clinician's selected treatment is on average reliably higher than human clinicians. In a large validation cohort independent of the training data, mortality was lowest in patients for whom clinicians' actual doses matched the AI decisions. Our model provides individualized and clinically interpretable treatment decisions for sepsis that could improve patient outcomes.

Review article: Sepsis in the emergency department - Part 3: Treatment

Although comprehensive guidelines for treatment of sepsis exist, current research continues to refine and revise several aspects of management. Imperatives for rapid administration of broad-spectrum antibiotics for all patients with sepsis may not be supported by contemporary data. Many patients may be better served by a more judicious approach allowing consideration of investigation results and evidence-based guidelines. Conventional fluid therapy has been challenged with early evidence supporting balanced, restricted fluid and early vasopressor use. Albumin, vasopressin and hydrocortisone have each been shown to support blood pressure and reduce catecholamine requirements but without effect on mortality, and as such should be considered for ED patients with septic shock on a case-by-case basis. Measurement of quality care in sepsis should incorporate quality of blood cultures and guideline-appropriateness of antibiotics, as well as timeliness of therapy. Local audit is an essential and effective means to improve practice. Multicentre consolidation of data through agreed minimum sepsis data sets would provide baseline quality data, required for the design and evaluation of interventions.

Sepsis: Early Recognition and Optimized Treatment

Sepsis is a life-threatening condition caused by infection and represents a substantial global health burden. Recent epidemiological studies showed that sepsis mortality rates have decreased, but that the incidence has continued to increase. Although a mortality benefit from early-goal directed therapy (EGDT) in patients with severe sepsis or septic shock was reported in 2001, three subsequent multicenter randomized studies showed no benefits of EGDT versus usual care. Nonetheless, the early administration of antibiotics and intravenous fluids is considered crucial for the treatment of sepsis. In 2016, new sepsis definitions (Sepsis-3) were issued, in which organ failure was emphasized and use of the terms "systemic inflammatory response syndrome" and "severe sepsis" was discouraged. However, early detection of sepsis with timely, appropriate interventions increases the likelihood of survival for patients with sepsis. Also, performance improvement programs have been associated with a significant increase in compliance with the sepsis bundles and a reduction in mortality. To improve sepsis management and reduce its burden, in 2017, the World Health Assembly and World Health Organization adopted a resolution that urged governments and healthcare workers to implement appropriate measures to address sepsis. Sepsis should be considered a medical emergency, and increasing the level of awareness of sepsis is essential.

Effects of arm elevation on radial artery pressure: a new method to distinguish hypovolemic shock and septic shock from hypotension

OBJECTIVES

In this prospective observational study, we investigated the variability in radial artery invasive blood pressure associated with arm elevation in patients with different hemodynamic types.

PATIENTS AND METHODS

We carried out a prospective observational study using data from 73 general anesthesia hepatobiliary postoperative adult patients admitted to an ICU over a 1-year period. A standard procedure was used for the arm elevation test. The value of invasive radial arterial pressure was recorded at baseline, and 30 and 60 s after the arm had been raised from 0° to 90°. We compared the blood pressure before versus after arm elevation, and between hemodynamically stable, hypovolemic shock, and septic shock patient groups.

RESULTS

In all 73 patients, systolic arterial pressure (SAP) decreased, diastolic arterial pressure (DAP) increased, and pulse pressure (PP) decreased at 30 and 60 s after arm elevation (P<0.01), but the mean arterial pressure (MAP) was unchanged (P>0.05). On comparing 30 and 60 s, there was no significant difference in SAP, DAP, PP, or MAP (P>0.05). In 40 hemodynamically stable patients, SAP and PP decreased, and DAP and MAP increased significantly at 30 and 60 s after arm elevation compared with baseline (P<0.01). In 16 hypovolemic patients, SAP, DAP, and MAP increased significantly compared with baseline at 30 and 60 s (P<0.01), but PP was unchanged (P>0.05). In 17 patients with septic shock, SAP, PP, and MAP decreased significantly versus baseline at 30 and 60 s (P<0.01), but DAP was unchanged (P>0.05). Comparison of the absolute value of pressure change of septic shock patients at 30 s after raising the arm showed that SAP, DAP, and MAP changes were significantly lower compared with those in hypovolemic shock and hemodynamically stable patients (P<0.01). The areas under the receiver operator characteristic curve for predicting septic shock was 0.930 [95% confidence interval (CI): 0.867-0.992, P< 0.001] for change value at 30 s after arm elevation of SAP. The best cut-off point for the SAP change value was -5 mmHg or less, with a sensitivity of 94.12%, a specificity of 80.36%, a positive likelihood ratio of 4.79 (95% CI: 2.8-8.2), and a negative likelihood ratio of 0.073 (95% CI: 0.01-0.5).

CONCLUSION

Our study shows that hypovolemic shock and septic shock patients have significantly different radial artery invasive blood pressure changes in an arm elevation test, which could be applied as a new method to distinguish hypovolemic shock and septic shock from hypotension.

Characteristics and Factors Associated With the Mortality of Hypotensive Patients Attending the Emergency Department

Background

The prevalence of hypotension in emergency departments (EDs) is approximately 1-2%, but is associated with a mortality rate of 8-15%. There has never been a study in Thailand examining the epidemiology or the risk factors for early mortality of patients presenting with hypotension in the ED. Therefore, this study aimed to define the characteristics, mortality rate within 48 h and associated factors of hypotensive patients at ED.

Methods

Data of patients with hypotension attending the ED of Thammasat University Hospital (TUH) were retrospectively studied.

Results

Of the 9,000 patients seen in the TUH ED, 233 were hypotensive for a prevalence of 2.5%. Patients were old, with a mean age of 61 ± 20 years. The most common presenting symptom was fever, and sepsis was the most common cause of hypotension. The mean systolic blood pressure (SBP) was 78 ± 8 mm Hg. Isotonic crystalloid volume resuscitation in first hour was 758 mL (interquartile range (IQR), 500 - 1,000) and the total volume to achieve a mean arterial pressure (MAP) ≥ 65 mm Hg was 1,142 mL (IQR, 500 - 1,500). Twenty-seven percent of patients needed vasopressor support. Nineteen patients died ≤ 48 h, giving a case fatality rate of 8.2%. Three independent factors associated with 48-h mortality were initial pulse rate > 100 beats/min (odds ratio (OR), 4.21; 95% confidence interval (CI), 1.05 - 16.88; P = 0.042), diagnosis of shock (OR, 13.74 (1.49 - 126.61); P = 0.021) and recurrent hypotension (OR, 6.91 (1.54 - 30.99); P = 0.012).

Conclusions

Hypotension in the ED was common and associated with high mortality rate. Better triage, patient monitoring and treatment may improve outcomes in these patients.

Increased circulating microRNA-122 is a biomarker for discrimination and risk stratification in patients defined by sepsis-3 criteria

Background

Sepsis is now operationally defined as life-threatening organ dysfunction caused by an infection, identified by an acute change in SOFA-Score of at least two points, including clinical chemistry such as creatinine or bilirubin concentrations. However, little knowledge exists about organ-specific microRNAs as potentially new biomarkers. Accordingly, we tested the hypotheses that micro-RNA-122, the foremost liver-related micro-RNA (miR), 1) discriminates between sepsis and infection, 2) is an early predictor for mortality, and 3) improves the prognostic value of the SOFA-score.

Methods

We analyzed 108 patients with sepsis (infection + increase SOFA-Score ≥2) within the first 24h of ICU admission and as controls 20 patients with infections without sepsis (infection + SOFA-Score ≤1). Total circulating miR was isolated from serum and relative miR-122 expression was measured (using spiked-in cel-miR-54) and associated with 30-day survival.

Results

30-day survival of the sepsis patients was 63%. miR-122 expression was 40-fold higher in non-survivors (p = 0.001) and increased almost 6-fold in survivors (p = 0.013) compared to controls. miR-122 serum-expression discriminated both between sepsis vs. infection (AUC 0.760, sensitivity 58.3%, specificity 95%) and survivors vs. non-survivors (AUC 0.728, sensitivity 42.5%, specificity 94%). Multivariate Cox-regression analysis revealed miR-122 (HR 4.3; 95%-CI 2.0–8.9, p<0.001) as independent prognostic factor for 30-day mortality. Furthermore, the predictive value for 30-day mortality of the SOFA-Score (AUC 0.668) was improved by adding miR-122 (AUC 0.743; net reclassification improvement 0.37, p<0.001; integrated discrimination improvement 0.07, p = 0.007).

Conclusions

Increased miR-122 serum concentration supports the discrimination between infection and sepsis, is an early and independent risk factor for 30-day mortality, and improves the prognostic value of the SOFA-Score, suggesting a potential role for miR-122 in sepsis-related prediction models.

Prospective Open-label Trial of Early Concomitant Vasopressin and Norepinephrine Therapy versus Initial Norepinephrine Monotherapy in Septic Shock

PURPOSE

Delays in achieving target mean arterial pressure (MAP) are associated with increased morbidity and mortality in patients with septic shock. This trial was conducted to test the hypothesis that early concomitant treatment with vasopressin and norepinephrine reduces the time to achieve and maintain target MAP compared with initial norepinephrine monotherapy.

METHODS

A single-center prospective open-label trial was conducted in patients with septic shock between November 2015 and June 2016 at a medical intensive care unit in an academic medical center. Initial norepinephrine monotherapy was initiated between November 2015 and February 2016. Between March and June 2016, vasopressin was initiated within 4 hours of norepinephrine. The primary outcome was time to achieving and maintaining MAP of 65 mm Hg for at least 4 hours that was compared between groups using the Student t test and examined using the Kaplan-Meier curve (Clinical Trials registration: NCT02454348).

RESULTS

Eighty-two patients were included (41 in each group). Patients treated with early concomitant vasopressin and norepinephrine more frequently had a positive culture (59% vs 37%, p=0.05) and grew nonlactose fermenting gram-negative bacilli (34% vs 10%, p=0.01) compared with patients treated with norepinephrine monotherapy, respectively. The median time to achieve and maintain MAP occurred faster in the early concomitant vasopressin and norepinephrine group, at 5.7 hours (interquartile range [IQR] 1.7-10.3 hrs), compared with 7.6 hours (IQR 3.6-16.7 hrs, p=0.058) in the norepinephrine group. Durations of therapy for norepinephrine or vasopressin, amount of norepinephrine received in the first 24 hours, norepinephrine dosage when MAP was achieved and maintained, maximum norepinephrine dosage, and mortality were similar between groups.

CONCLUSION

Patients treated with early concomitant vasopressin and norepinephrine achieved and maintained MAP of 65 mm Hg faster than those receiving initial norepinephrine monotherapy, suggesting that overcoming vasopressin deficiency sooner may reduce the time patients spend in the early phase of septic shock.

Predictors of response to fixed-dose vasopressin in adult patients with septic shock

Background

Vasopressin is often utilized for hemodynamic support in patients with septic shock. However, the most appropriate patient to initiate therapy in is unknown. This study was conducted to determine factors associated with hemodynamic response to fixed-dose vasopressin in patients with septic shock.

Methods

Single-center, retrospective cohort of patients receiving fixed-dose vasopressin for septic shock for at least 6 h with concomitant catecholamines in the medical, surgical, or neurosciences intensive care unit (ICU) at a tertiary care center. Patients were classified as responders or non-responders to fixed-dose vasopressin. Response was defined as a decrease in catecholamine dose requirements and achievement of mean arterial pressure ≥ 65 mmHg at 6 h after initiation of vasopressin.

Results

A total of 938 patients were included: 426 responders (45%), 512 non-responders (55%). Responders had lower rates of in-hospital (57 vs. 72%; P < 0.001) and ICU mortality (50 vs. 68%; P < 0.001), and increased ICU-free days at day 14 and hospital-free days at day 28 (2.3 ± 3.8 vs. 1.6 ± 3.3; P < 0.001 and 4.2 ± 7.2 vs. 2.8 ± 6.0; P < 0.001, respectively). On multivariable analysis, non-medical ICU location was associated with increased response odds (OR 1.70; P = 0.0049) and lactate at vasopressin initiation was associated with decreased response odds (OR 0.93; P = 0.0003). Factors not associated with response included APACHE III score, SOFA score, corticosteroid use, and catecholamine dose.

Conclusion

In this evaluation, 45% responded to the addition of vasopressin with improved outcomes compared to non-responders. The only factors found to be associated with vasopressin response were ICU location and lactate concentration.

Negative Fluid Balance in Sepsis: When and How?

Fluid resuscitation plays a fundamental role in the treatment of septic shock. Administration of inappropriately large quantities of fluid may lead to volume overload, which is increasingly recognized as an independent risk factor for morbidity and mortality in critical illness. In the early treatment of sepsis, timely fluid challenges should be given to optimize organ perfusion, but continuous positive fluid balance is discouraged. In fact, achievement of a negative fluid balance during treatment of sepsis is associated with better outcomes. This review will discuss the relationship between fluid overload and unfavorable outcomes in sepsis, and how fluid overload can be prevented and managed.

Vasopressors in Sepsis

BACKGROUND

Sepsis accounts for 10% of intensive care unit admissions and significant healthcare costs. Although the mortality rate from sepsis has been decreasing with better critical care, early identification of septic patients, and prompt interventions, the mortality rate remains 20%-30%.

METHOD

Review of the English-language literature.

RESULTS

Norepinephrine is the first-line vasopressor in shock and is associated with a lower mortality rate as well as fewer adverse effects. Dopamine has similar actions but is associated with significantly more tachydysrhythmias and should be reserved for patients with bradycardia. Epinephrine and vasopressin are appropriate second-line vasopressors and may enable use of lower doses of norepinephrine while improving hemodynamics. Inotropes may be added in patients with cardiac dysfunction.

CONCLUSION

Appropriate treatment of sepsis includes prompt identification, early antimicrobial drug therapy, appropriate fluid resuscitation, and initiation of vasopressors in the presence of continued septic shock. Further research needs to be done to better understand the ideal timing of the addition of a second agent and the optimal combinations of vasopressors for individual patients.

The crashing patient: hemodynamic collapse

PURPOSE OF REVIEW

Rapid restoration of tissue perfusion and oxygenation are the main goals in the resuscitation of a patient with circulatory collapse. This review will focus on providing an evidence based framework of the technological and conceptual advances in the evaluation and management of the patient with cardiovascular collapse.

RECENT FINDINGS

The initial approach to the patient in cardiovascular collapse continues to be based on the Ventilate-Infuse-Pump rule. Point of care ultrasound is the preferred modality for the initial evaluation of undifferentiated shock, providing information to narrow the differential diagnosis, to assess fluid responsiveness and to evaluate the response to therapy. After the initial phase of resuscitative fluid administration, which focuses on re-establishing a mean arterial pressure to 65 mmHg, the use of dynamic parameters to assess preload responsiveness such as the passive leg raise test, stroke volume variation, pulse pressure variation and collapsibility of the inferior vena cava in mechanically ventilated patients is recommended.

SUMMARY

The crashing patient remains a clinical challenge. Using an integrated approach with bedside ultrasound, dynamic parameters for the evaluation of fluid responsiveness and surrogates of evaluation of tissue perfusion have made the assessment of the patient in shock faster, safer and more physiologic.

Association of Positive Fluid Balance and Mortality in Sepsis and Septic Shock in An Australian Cohort

In patients with septic shock, a correlation between positive fluid balance and worsened outcomes has been reported in multiple observational studies worldwide. No published data exists in an Australasian cohort. We set out to explore this association in our institution. We conducted a retrospective audit of patient records from August 2012 to May 2015 in a single-centre, 24-bed surgical and medical intensive care unit (ICU) in Sydney, Australia. All patients with septic shock were included. Exclusion criteria included length of stay less than 24 hours or vasopressors needed for less than six hours. Data was gathered on fluid balance for the first seven days of ICU admission, biochemical data and other clinical indices. The primary outcome measure was survival to hospital discharge. One hundred and eighty-six patients with septic shock were included, with an overall hospital mortality of 23.7%. Seventy-five percent of patients required mechanical ventilation, and 27.4% required haemodialysis. The mean daily fluid balance on the first day of admission was positive 1,424 ml and 1,394 ml for ICU and hospital survivors, respectively. On average, the daily fluid balance for non-survivors was higher than the survivors: ICU non-survivors were 602 (95% confidence intervals 230, 974) ml (P=0.0015) and hospital non-survivors were 530 [95% confidence intervals 197, 863] ml (P=0.0017) higher than the survivors. In line with other recently published data, after adjustment for confounders (severity of illness based on the Acute Physiology and Chronic Health Evaluation score) we found a correlation between positive fluid balance and worsened hospital mortality in critically ill patients with sepsis and septic shock. Further research investigating rational use of fluids in this patient group is needed.

Septic shock and the use of norepinephrine in an intermediate care unit: Mortality and adverse events

BACKGROUND

Septic shock is associated with high mortality. Aged and multimorbid patients are not always eligible for intensive care units. Norepinephrine is an accepted treatment for hypotension in septic shock. It is unknown whether norepinephrine has a place in treatment outside an intensive care unit and when given peripherally.

OBJECTIVES

To describe mortality, Acute Physiology And Chronic Health Evaluation (APACHE-II), time to mean arterial pressure >65 mmHg, and adverse events in patients with septic shock receiving norepinephrine peripherally in an intermediate care unit.

METHODS

From a retrospective chart review of 91 patients with septic shock treated with norepinephrine for hypotension, ward mortality, 30-, 60- and 90-day mortality, standardized mortality ratio (SMR) and adverse events (necrosis and arrhythmia) were analysed. Administration route via peripheral venous catheter or central venous catheter was registered.

RESULTS

Median age was 81 (43-96) years and median APACHE-II score was 26 (12-42). Observed ward mortality was 27.5% (SMR 0.443, 95% CI: 0.287-0.654), and 30-day and 90-day mortality were 47.2% and 58.2%, respectively.

CONCLUSIONS

Elderly patients with septic shock treated with norepinephrine displayed a better survival in the ward and at 30 days than expected. Our retrospective study did not indicate frequent complications when administering norepinephrine via a peripheral venous catheter.

Efficacy and Safety of the Early Addition of Vasopressin to Norepinephrine in Septic Shock

BACKGROUND

Delays in achievement of target mean arterial pressure (MAP) have been associated with increased mortality in patients with septic shock. Vasopressin may be added to norepinephrine to raise MAP or decrease norepinephrine dosage. The purpose of this study was to determine whether early initiation of vasopressin to norepinephrine resulted in a reduced time to target MAP compared to norepinephrine monotherapy.

METHODS

This retrospective cohort study compared early addition of vasopressin within 4 hours of septic shock onset to norepinephrine versus initial norepinephrine monotherapy in medically, critically ill patients with septic shock admitted from May 2014 to October 2015. Time to goal MAP was compared using Student t test and examined with Kaplan-Meier curves. Changes in Sequential Organ Failure Assessment (SOFA) scores were evaluated with Wilcoxon rank sum test.

RESULTS

Each group contained 48 patients. Mean arterial pressure (61.5 vs 58.6 mm Hg) and intravenous fluid volume received at vasopressor initiation (14.3 vs 25.2 hours, P = .014) were similar. Patients started on early vasopressin achieved and maintained goal MAP sooner (6.2 vs 9.9 hours, P = .023), experienced greater reductions in SOFA scores at 72 hours (-4 vs -1, P = .012), and had shorter hospital durations (343 vs 604 hours, P = .014). Not initiating early vasopressin trended toward an association with increased time to goal MAP (P = .067).

CONCLUSION

Early initiation of vasopressin in patients with septic shock may achieve and maintain goal MAP sooner and resolve organ dysfunction at 72 hours more effectively than later or no initiation.