Vasopressors in septic shock: which, when, and how much?

Apelin-13 administration allows for norepinephrine sparing in a rat model of cecal ligation and puncture-induced septic shock

BACKGROUND

Infusion of exogenous catecholamines (i.e., norepinephrine [NE] and dobutamine) is a recommended treatment for septic shock with myocardial dysfunction. However, sustained catecholamine infusion is linked to cardiac toxicity and impaired responsiveness. Several pre-clinical and clinical studies have investigated the use of alternative vasopressors in the treatment of septic shock, with limited benefits and generally no effect on mortality. Apelin-13 (APL-13) is an endogenous positive inotrope and vasoactive peptide and has been demonstrated cardioprotective with vasomodulator and sparing life effects in animal models of septic shock. A primary objective of this study was to evaluate the NE-sparing effect of APL-13 infusion in an experimental sepsis-induced hypotension.

METHODS

For this goal, sepsis was induced by cecal ligation and puncture (CLP) in male rats and the arterial blood pressure (BP) monitored continuously via a carotid catheter. Monitoring, fluid resuscitation and experimental treatments were performed on conscious animals. Based on pilot assays, normal saline fluid resuscitation (2.5 mL/Kg/h) was initiated 3 h post-CLP and maintained up to the endpoint. Thus, titrated doses of NE, with or without fixed-doses of APL-13 or the apelin receptor antagonist F13A co-infusion were started when 20% decrease of systolic BP (SBP) from baseline was achieved, to restore SBP values ≥ 115 ± 1.5 mmHg (baseline average ± SEM).

RESULTS

A reduction in mean NE dose was observed with APL-13 but not F13A co-infusion at pre-determined treatment time of 4.5 ± 0.5 h (17.37 ± 1.74 µg/Kg/h [APL-13] vs. 25.64 ± 2.61 µg/Kg/h [Control NE] vs. 28.60 ± 4.79 µg/Kg/min [F13A], P = 0.0491). A 60% decrease in NE infusion rate over time was observed with APL-13 co-infusion, (p = 0.008 vs NE alone), while F13A co-infusion increased the NE infusion rate over time by 218% (p = 0.003 vs NE + APL-13). Associated improvements in cardiac function are likely mediated by (i) enhanced left ventricular end-diastolic volume (0.18 ± 0.02 mL [Control NE] vs. 0.30 ± 0.03 mL [APL-13], P = 0.0051), stroke volume (0.11 ± 0.01 mL [Control NE] vs. 0.21 ± 0.01 mL [APL-13], P < 0.001) and cardiac output (67.57 ± 8.63 mL/min [Control NE] vs. 112.20 ± 8.53 mL/min [APL-13], P = 0.0036), and (ii) a reduced effective arterial elastance (920.6 ± 81.4 mmHg/mL/min [Control NE] vs. 497.633.44 mmHg/mL/min. [APL-13], P = 0.0002). APL-13 administration was also associated with a decrease in lactate levels compared to animals only receiving NE (7.08 ± 0.40 [Control NE] vs. 4.78 ± 0.60 [APL-13], P < 0.01).

CONCLUSION

APL-13 exhibits NE-sparing benefits in the treatment of sepsis-induced shock, potentially reducing deleterious effects of prolonged exogenous catecholamine administration.

Beta-Blockers as an Immunologic and Autonomic Manipulator in Critically Ill Patients: A Review of the Recent Literature

The autonomic nervous system plays a key role in maintaining body hemostasis through both the sympathetic and parasympathetic nervous systems. Sympathetic overstimulation as a reflex to multiple pathologies, such as septic shock, brain injury, cardiogenic shock, and cardiac arrest, could be harmful and lead to autonomic and immunologic dysfunction. The continuous stimulation of the beta receptors on immune cells has an inhibitory effect on these cells and may lead to immunologic dysfunction through enhancing the production of anti-inflammatory cytokines, such as interleukin-10 (IL-10), and inhibiting the production of pro-inflammatory factors, such as interleukin-1B IL-1B and tissue necrotizing factor-alpha (TNF-alpha). Sympathetic overstimulation-induced autonomic dysfunction may also happen due to adrenergic receptor insensitivity or downregulation. Administering anti-adrenergic medication, such as beta-blockers, is a promising treatment to compensate against the undesired effects of adrenergic surge. Despite many misconceptions about beta-blockers, beta-blockers have shown a promising effect in decreasing mortality in patients with critical illness. In this review, we summarize the recently published articles that have discussed using beta-blockers as a promising treatment to decrease mortality in critically ill patients, such as patients with septic shock, traumatic brain injury, cardiogenic shock, acute decompensated heart failure, and electrical storm. We also discuss the potential pathophysiology of beta-blockers in various types of critical illness. More clinical trials are encouraged to evaluate the safety and effectiveness of beta-blockers in improving mortality among critically ill patients.

Comparison of Early and Late Norepinephrine Administration in Patients with Septic Shock: A Systematic Review and Meta-analysis

BACKGROUND

Vasopressor administration at an appropriate time is crucial, but the optimal timing remains controversial.

RESEARCH QUESTION

Does early vs late norepinephrine administration impact the prognosis of septic shock?

STUDY DESIGN AND METHODS

Searches were conducted on PubMed, EMBASE, the Cochrane Library, and KMBASE. We included studies of adults with sepsis and categorized patients into an early and late norepinephrine group according to specific time points or differences in norepinephrine use protocols. The primary outcome was overall mortality. The secondary outcomes included length of stay in the ICU, days free from ventilator use, days free from renal replacement therapy, days free from vasopressor use, adverse events, and total fluid volume.

RESULTS

Twelve studies (four randomized controlled trials [RCTs] and eight observational studies) comprising 7,281 patients were analyzed. For overall mortality, no significant difference was found between the early norepinephrine group and late norepinephrine group in RCTs (OR, 0.70; 95% CI, 0.41-1.19) or observational studies (OR, 0.83; 95% CI, 0.54-1.29). In the two RCTs without a restrictive fluid strategy that prioritized vasopressors and lower IV fluid volumes, the early norepinephrine group showed significantly lower mortality than the late norepinephrine group (OR, 0.49; 95%, CI, 0.25-0.96). The early norepinephrine group demonstrated more mechanical ventilator-free days in observational studies (mean difference, 4.06; 95% CI, 2.82-5.30). The incidence of pulmonary edema was lower in the early norepinephrine group in the three RCTs that reported this outcome (OR, 0.43; 95% CI, 0.25-0.74). No differences were found in the other secondary outcomes.

INTERPRETATION

Overall mortality did not differ significantly between early and late norepinephrine administration for septic shock. However, early norepinephrine administration seemed to reduce pulmonary edema incidence, and mortality improvement was observed in studies without fluid restriction interventions, favoring early norepinephrine use.

Beyond the Horizon: A Comprehensive Review of Contemporary Strategies in Sepsis Management Encompassing Predictors, Diagnostic Tools, and Therapeutic Advances

This comprehensive review offers a detailed exposition of contemporary strategies in sepsis management, encompassing predictors, diagnostic tools, and therapeutic advances. The analysis elucidates the dynamic nature of sepsis, emphasizing the crucial role of early detection and intervention. The multifaceted strategies advocate for a holistic and personalized approach to sepsis care from traditional clinical methodologies to cutting-edge technologies. The implications for clinical practice underscore clinicians' need to adapt to evolving definitions, integrate advanced diagnostic tools, and embrace precision medicine. Integrating artificial intelligence and telemedicine necessitates a commitment to training and optimization. Judicious antibiotic use and recognition of global health disparities emphasize the importance of a collaborative, global effort in sepsis care. Looking ahead, recommendations for future research underscore priorities such as longitudinal studies on biomarkers, precision medicine trials, implementation science in technology, global health interventions, and innovative antibiotic stewardship strategies. These research priorities aim to contribute to transformative advancements in sepsis management, ultimately enhancing patient outcomes and reducing the global impact of this critical syndrome.

A Clinical Review of Vasopressors in Emergency Medicine

BACKGROUND

Vasopressor medications raise blood pressure through vasoconstriction and are essential in reversing the hypotension seen in many critically ill patients. Previously, vasopressor administration was largely limited to continuous infusions through central venous access.

OBJECTIVES OF THE REVIEW

This review addresses the clinical use of vasopressors in various shock states, including practical considerations and innovations in vasopressor administration. The focus is on the clinical administration of vasopressors across a range of shock states, including hypovolemic, distributive, cardiogenic, and obstructive shock.

DISCUSSION

Criteria for starting vasopressors are not clearly defined, though early use may be beneficial. A number of physiologic factors affect the body's response to vasopressors, such as acidosis and adrenal insufficiency. Peripheral and push-dose administration of vasopressors are becoming more common. Distributive shock is characterized by inappropriate vasodilation and vasopressors play a crucial role in maintaining adequate blood pressure. The use of vasopressors is more controversial in hypovolemic shock, as the preferred treatment is correction of the volume deficit. Evidence for vasopressors is limited in cardiogenic shock. For obstructive shock, vasopressors can temporize a patient's blood pressure until definitive therapy can reverse the underlying cause.

CONCLUSION

Across the categories of shock states, norepinephrine has wide applicability and is a reasonable first-line agent for shock of uncertain etiology. Keeping a broad differential when hypotension is refractory to vasopressors may help to identify adjunctive treatments in physiologic states that impair vasopressor effectiveness. Peripheral administration of vasopressors is safe and facilitates early administration, which may help to improve outcomes in some shock states.

Sepsis as a Potential Risk Factor for Upper Gastrointestinal Bleeding in Critically Ill Patients: A Systematic Review and Meta-analysis

Purpose: Sepsis is a common and critical condition in intensive care units (ICUs) known to complicate patient outcomes. Previous studies have indicated an association between sepsis and various ICU morbidities, including upper gastrointestinal bleeding (UGIB). However, the extent of this relationship and its implications in ICU settings remain inadequately quantified. This study aims to elucidate the association between sepsis and the risk of UGIB in ICU patients. Methods: A comprehensive meta-analysis was conducted, encompassing nine studies with a total of nearly 9000 participants. These studies reported events for both sepsis and nonsepsis patients separately. Pooled odds ratios (ORs) were calculated to assess the risk of UGIB in septic versus nonseptic ICU patients. Subgroup analyses were conducted based on age and study design, and both unadjusted and adjusted ORs were examined. Results: The pooled OR indicated a significant association between sepsis and UGIB (OR = 3.276, 95% CI: 1.931 to 5.557). Moderate heterogeneity was observed (I² = 43.9%). The association was significant in adults (pooled OR = 4.083) but not in children. No difference in association was found based on the study design. Unadjusted and adjusted ORs differed slightly, indicating the influence of confounding factors. Conclusion: This meta-analysis reveals a significant association between sepsis and an increased risk of UGIB in ICU patients, particularly in adults. These findings highlight the need for vigilant monitoring and proactive management of septic ICU patients to mitigate the risk of UGIB. Future research should focus on understanding the underlying mechanisms and developing tailored preventive strategies.

Acute Kidney Injury in Sepsis

Sepsis-associated kidney injury is common in critically ill patients and significantly increases morbidity and mortality rates. Several complex pathophysiological factors contribute to its presentation and perpetuation, including macrocirculatory and microcirculatory changes, mitochondrial dysfunction, and metabolic reprogramming. Recovery from acute kidney injury (AKI) relies on the evolution towards adaptive mechanisms such as endothelial repair and tubular cell regeneration, while maladaptive repair increases the risk of progression to chronic kidney disease. Fundamental management strategies include early sepsis recognition and prompt treatment, through the administration of adequate antimicrobial agents, fluid resuscitation, and vasoactive agents as needed. In septic patients, organ-specific support is often required, particularly renal replacement therapy (RRT) in the setting of severe AKI, although ongoing debates persist regarding the ideal timing of initiation and dosing of RRT. A comprehensive approach integrating early recognition, targeted interventions, and close monitoring is essential to mitigate the burden of SA-AKI and improve patient outcomes in critical care settings.

Sex- and Gender-Based Analysis on Norepinephrine Use in Septic Shock: Why Is It Still a Male World?

Sex and gender are fundamental health determinants and their role as modifiers of treatment response is increasingly recognized. Norepinephrine is a cornerstone of septic shock management and its use is based on the highest level of evidence compared to dopamine. The related 2021 Surviving Sepsis Campaign (SCC) recommendation is presumably applicable to both females and males; however, a sex- and gender-based analysis is lacking, thus not allowing generalizable conclusions. This paper was aimed at exploring whether sex- and gender-disaggregated data are available in the evidence supporting this recommendation. For all the studies underpinning it, four pairs of authors, including a woman and a man, extracted data concerning sex and gender, according to the Sex and Gender Equity in Research guidelines. Nine manuscripts were included with an overall population of 2126 patients, of which 43.2% were females. No sex analysis was performed and gender was never reported. In conclusion, the present manuscript highlighted that the clinical studies underlying the SCC recommendation of NE administration in septic shock have neglected the likely role of sex and gender as modifiers of treatment response, thus missing the opportunity of sex- and gender-specific guidelines.

Inflammatory liver diseases and susceptibility to sepsis

Patients with inflammatory liver diseases, particularly alcohol-associated liver disease and metabolic dysfunction-associated fatty liver disease (MAFLD), have higher incidence of infections and mortality rate due to sepsis. The current focus in the development of drugs for MAFLD is the resolution of non-alcoholic steatohepatitis and prevention of progression to cirrhosis. In patients with cirrhosis or alcoholic hepatitis, sepsis is a major cause of death. As the metabolic center and a key immune tissue, liver is the guardian, modifier, and target of sepsis. Septic patients with liver dysfunction have the highest mortality rate compared with other organ dysfunctions. In addition to maintaining metabolic homeostasis, the liver produces and secretes hepatokines and acute phase proteins (APPs) essential in tissue protection, immunomodulation, and coagulation. Inflammatory liver diseases cause profound metabolic disorder and impairment of energy metabolism, liver regeneration, and production/secretion of APPs and hepatokines. Herein, the author reviews the roles of (1) disorders in the metabolism of glucose, fatty acids, ketone bodies, and amino acids as well as the clearance of ammonia and lactate in the pathogenesis of inflammatory liver diseases and sepsis; (2) cytokines/chemokines in inflammatory liver diseases and sepsis; (3) APPs and hepatokines in the protection against tissue injury and infections; and (4) major nuclear receptors/signaling pathways underlying the metabolic disorders and tissue injuries as well as the major drug targets for inflammatory liver diseases and sepsis. Approaches that focus on the liver dysfunction and regeneration will not only treat inflammatory liver diseases but also prevent the development of severe infections and sepsis.

Challenges in Septic Shock: From New Hemodynamics to Blood Purification Therapies

Sepsis and septic shock are associated with high mortality, with diagnosis and treatment remaining a challenge for clinicians. Their management classically encompasses hemodynamic resuscitation, antibiotic treatment, life support, and focus control; however, there are aspects that have changed. This narrative review highlights current and avant-garde methods of handling patients experiencing septic shock based on the experience of its authors and the best available evidence in a context of uncertainty. Following the first recommendation of the Surviving Sepsis Campaign guidelines, it is recommended that specific sepsis care performance improvement programs are implemented in hospitals, i.e., "Sepsis Code" programs, designed ad hoc, to achieve this goal. Regarding hemodynamics, the importance of perfusion and hemodynamic coherence stand out, which allow for the recognition of different phenotypes, determination of the ideal time for commencing vasopressor treatment, and the appropriate fluid therapy dosage. At present, this is not only important for the initial timing, but also for de-resuscitation, which involves the early weaning of support therapies, directed elimination of fluids, and fluid tolerance concept. Finally, regarding blood purification therapies, those aimed at eliminating endotoxins and cytokines are attractive in the early management of patients in septic shock.

The Impact of Inotropes and Vasopressors on Cerebral Oxygenation in Patients with Traumatic Brain Injury and Subarachnoid Hemorrhage: A Narrative Review

Traumatic brain injury (TBI) and subarachnoid hemorrhage (SAH) are critical neurological conditions that necessitate specialized care in the Intensive Care Unit (ICU). Managing cerebral perfusion pressure (CPP) and mean arterial pressure (MAP) is of primary importance in these patients. To maintain targeted MAP and CPP, vasopressors and/or inotropes are commonly used. However, their effects on cerebral oxygenation are not fully understood. The aim of this review is to provide an up-to date review regarding the current uses and pathophysiological issues related to the use of vasopressors and inotropes in TBI and SAH patients. According to our findings, despite achieving similar hemodynamic parameters and CPP, the effects of various vasopressors and inotropes on cerebral oxygenation, local CBF and metabolism are heterogeneous. Therefore, a more accurate understanding of the cerebral activity of these medications is crucial for optimizing patient management in the ICU setting.

Impact of CytoSorb Hemoadsorption Therapy on Fluid Balance in Patients with Septic Shock

Recent in vitro studies have investigated the effects of hemoadsorption therapy on endothelial function in sepsis showing a reduction in markers of endothelial dysfunction, but, to this day, there are no clinical studies proving whether this approach could actually positively influence the disturbed vascular barrier function in septic conditions. We retrospectively analyzed data on administered fluid volumes and catecholamines in 124 septic shock patients. We collected catecholamine and volume requirements and calculated the volume balance within different time periods to obtain an assumption on the stability of the vascular barrier. Regarding the entire study cohort, our findings revealed a significant reduction in fluid balance at 72 h (T72) compared to both baseline (T0) and the 24 h mark (T24). Fluid balances from T72-T0 were significantly lower in hospital survivors compared with non-survivors. Patients who received a second catecholamine had a significantly lower in-hospital mortality. Our findings suggest that the applied treatment regimen including hemoadsorption therapy is associated with a reduced positive fluid balance paralleled by reductions in vasopressor needs, suggesting a potential positive effect on endothelial integrity. These results, derived from a large cohort of patients, provide valuable insights on the multiple effects of hemoadsorption treatment in septic shock patients.

Evaluating the factors affecting clinical outcomes in critically ill COVID-19 unvaccinated patients admitted to the intensive care unit in a lower-middle-income country

Background

COVID-19, the most destructive pandemic of this century, caused the highest mortality rate among ICU patients. The evaluation of these patients is insufficient in lower-middle-income countries with limited resources during pandemics. As a result, our primary goal was to examine the characteristics of patients at baseline as well as their survival outcomes, and propose mortality predictors for identifying and managing the most vulnerable patients more effectively and quickly.

Methods

A prospective analysis of COVID-19 ICU-admitted patients was conducted in our healthcare centre in Iran, from 1 April until 20 May 2020. Ninety-three patients were included in the study, and all were unvaccinated. A multi-variate logistic regression was conducted to evaluate mortality-associated factors.

Results

There were 53 non-survivors among our ICU-admitted patients. The mean duration from symptoms' onset to hospitalization was 6.92 ± 4.27 days, and from hospitalization to ICU admission was 2.52 ± 3.61 days. The average hospital stay for patients was 13.23 ± 10.43 days, with 8.84 ± 7.53 days in the ICU. Non-survivors were significantly older, had significantly lower haemoglobin levels and higher creatine phosphokinase levels compared to survivors. They had marginally lower SpO2 levels at admission, higher vasopressor administrations, and were intubated more significantly during their ICU stay. The use of immunosuppressive drugs was also significantly higher in non-survivors. Logistic regression revealed that a one-point increase in APACHE II score at ICU admission increased mortality by 6%, and the presence of underlying diseases increased mortality by 4.27 times.

Conclusion

The authors presented clinical mortality prediction factors for critically ill patients infected with COVID-19. Additional studies are necessary to identify more generalized mortality indicators for these patients in lower-middle-income countries.

Author Response

How to cite this article: Rajbanshi LK, Arjyal B. Author Response. Indian J Crit Care Med 2024;28(1):90-91.

Micro-lightguide spectrophotometry assessment of hepatic and intestinal microcirculation in endotoxemic rats during intravenous treatment with angiotensin II

INTRODUCTION

During septic shock, impairment of microcirculation leads to enhanced permeability of intestinal mucosa triggered by generalized vasodilation and capillary leak. Intravenous angiotensin II (AT-II) has been approved for the treatment of septic shock; however, no in-vivo data exist on the influence of AT-II on hepatic and intestinal microcirculation.

MATERIAL AND METHODS

Sixty male Lewis rats were randomly assigned to six study groups (each n = 10): sham, lipopolysaccharide-induced septic shock, therapy with low- or high-dose AT-II (50 or 100 ng/kg/min, respectively), and septic shock treated with low- or high-dose AT-II. After median laparotomy, hepatic and intestinal microcirculation measures derived from micro-lightguide spectrophotometry were assessed for 3 h and included oxygen saturation (SO2), relative blood flow (relBF) and relative hemoglobin level (relHb). Hemodynamic measurements were performed using a left ventricular conductance catheter, and blood samples were taken hourly to analyze blood gasses and systemic cytokines.

RESULTS

AT-II increased mean arterial pressure in a dose-dependent manner in both septic and non-septic animals (p < 0.001). Lower hepatic and intestinal SO2 (both p < 0.001) were measured in animals without endotoxemia who received high-dose AT-II treatment, however, significantly impaired cardiac output was also reported in this group (p < 0.001). In endotoxemic rats, hepatic relBF and relHb were comparable among the treatment groups; however, hepatic SO2 was reduced during low- and high-dose AT-II treatment (p < 0.001). In contrast, intestinal SO2 remained unchanged despite treatment with AT-II. Intestinal relBF (p = 0.028) and interleukin (IL)-10 plasma levels (p < 0.001) were significantly elevated during treatment with high-dose AT-II compared with low-dose AT-II.

CONCLUSIONS

A dose-dependent decrease of hepatic and intestinal microcirculation during therapy with AT-II in non-septic rats was observed, which might have been influenced by a corresponding reduction in cardiac output due to elevated afterload. While hepatic microcirculation was reduced during endotoxemia, no evidence for a reduction in intestinal microcirculation facilitated by AT-II was found. In contrast, both intestinal relBF and anti-inflammatory IL-10 levels were increased during high-dose AT-II treatment.

Navigating the Landscape of Hydrocortisone Administration in Septic Shock: Current Concepts and Future Directions

Sepsis remains a formidable challenge in critical care medicine, often culminating in a life-threatening condition known as septic shock. This review article navigates the intricate landscape of hydrocortisone administration in septic shock management, delving into historical perspectives, current evidence, controversies, mechanisms of action, practical considerations, and the importance of precision medicine. Hydrocortisone's role as an adjunctive therapy is explored, highlighting its potential to stabilize hemodynamics, mitigate the inflammatory response, and improve patient outcomes. However, debates persist regarding patient selection, dosing regimens, safety profiles, and long-term consequences. The future of septic shock management lies in emerging therapies, precision medicine approaches, biomarker discovery, and targeted interventions. Moving forward, exploring novel therapeutic avenues, understanding patient-specific responses, and uncovering potential biomarkers will be crucial in advancing septic shock treatment strategies. Clinical guidelines provide a foundation, but individualized patient care, interdisciplinary collaboration, and ongoing research are essential to optimize treatment strategies. This article underscores the call for continued research and evidence-based practice as we strive to enhance the care of septic shock patients and pursue improved outcomes in this critical condition. Embracing future developments in the field will enable us to adapt and refine our approach, ultimately contributing to the advancement of septic shock management.

Impact of norepinephrine on immunity and oxidative metabolism in sepsis

Sepsis is a major health problem in the United States (US), constituting a leading contributor to mortality among critically ill patients. Despite advances in treatment the underlying pathophysiology of sepsis remains elusive. Reactive oxygen species (ROS) have a significant role in antimicrobial host defense and inflammation and its dysregulation leads to maladaptive responses because of excessive inflammation. There is growing evidence for crosstalk between the central nervous system and the immune system in response to infection. The hypothalamic-pituitary and adrenal axis and the sympathetic nervous system are the two major pathways that mediate this interaction. Epinephrine (Epi) and norepinephrine (NE), respectively are the effectors of these interactions. Upon stimulation, NE is released from sympathetic nerve terminals locally within lymphoid organs and activate adrenoreceptors expressed on immune cells. Similarly, epinephrine secreted from the adrenal gland which is released systemically also exerts influence on immune cells. However, understanding the specific impact of neuroimmunity is still in its infancy. In this review, we focus on the sympathetic nervous system, specifically the role the neurotransmitter norepinephrine has on immune cells. Norepinephrine has been shown to modulate immune cell responses leading to increased anti-inflammatory and blunting of pro-inflammatory effects. Furthermore, there is evidence to suggest that norepinephrine is involved in regulating oxidative metabolism in immune cells. This review attempts to summarize the known effects of norepinephrine on immune cell response and oxidative metabolism in response to infection.

Dose-related effects of norepinephrine on early-stage endotoxemic shock in a swine model

Background

The benefits of early use of norepinephrine in endotoxemic shock remain unknown. We aimed to elucidate the effects of different doses of norepinephrine in early-stage endotoxemic shock using a clinically relevant large animal model.

Methods

Vasodilatory shock was induced by endotoxin bolus in 30 Bama suckling pigs. Treatment included fluid resuscitation and administration of different doses of norepinephrine, to induce return to baseline mean arterial pressure (MAP). Fluid management, hemodynamic, microcirculation, inflammation, and organ function variables were monitored. All animals were supported for 6 h after endotoxemic shock.

Results

Infused fluid volume decreased with increasing norepinephrine dose. Return to baseline MAP was achieved more frequently with doses of 0.8 µg/kg/min and 1.6 µg/kg/min (P <0.01). At the end of the shock resuscitation period, cardiac index was higher in pigs treated with 0.8 µg/kg/min norepinephrine (P <0.01), while systemic vascular resistance was higher in those receiving 0.4 µg/kg/min (P <0.01). Extravascular lung water level and degree of organ edema were higher in animals administered no or 0.2 µg/kg/min norepinephrine (P <0.01), while the percentage of perfused small vessel density (PSVD) was higher in those receiving 0.8 µg/kg/min (P <0.05) and serum lactate was higher in the groups administered no and 1.6 µg/kg/min norepinephrine (P <0.01).

Conclusions

The impact of norepinephrine on the macro- and micro-circulation in early-stage endotoxemic shock is dose-dependent, with very low and very high doses resulting in detrimental effects. Only an appropriate norepinephrine dose was associated with improved tissue perfusion and organ function.

Updates in the Management of Dengue Shock Syndrome: A Comprehensive Review

Dengue is a very serious public health problem that can manifest a wide range of symptoms from asymptomatic to fatal conditions, such as dengue shock syndrome (DSS). It is a life-threatening mosquito-borne viral infection widely spread in tropical areas. Dengue virus transmission occurs from an infected Aedes mosquito to humans. Various factors are responsible for the occurrence of the disease, such as viral load, age of the host, immune status of the host, and genetic variability. Dengue infection occurs in three phases: febrile, critical, and recovery. The febrile phase lasts for seven days and manifests symptoms such as high-grade fever, headache, arthralgia, and backache, and in some cases, the upper respiratory tract and gastrointestinal tract are also involved. Severe dengue is characterized by endothelial dysfunction that causes vascular permeability and plasma leakage. The fundamental mechanisms of these immune pathologies are not yet known. Dengue manifests various complications such as dengue encephalopathy, encephalitis, stroke, ocular involvement, acute transverse myelitis, myalgia, and cerebellar syndrome, but the most commonly seen is liver involvement. Dengue is managed supportively because there are no proven curative treatments. The cornerstone of care during the critical period of dengue is prudent fluid resuscitation. The first fluid of preference is a crystalloid. Prophylactic transfusion of platelets is not advised. The occurrence of four antigenically different dengue virus serotypes, each able to elicit a cross-reactive and disease-enhancing antibody response against the other three serotypes, has made the creation of the dengue vaccine a difficult undertaking. The development of a dengue vaccine has faced significant challenges due to a lack of the best animal models and a variety of immunological conditions in people, particularly in endemic locations. Dengvaxia is a live attenuated vaccine, which was developed by Sanofi. It is made up of four chimeric vaccine viruses produced by Vero cells.

Association between diastolic blood pressure during the first 24 h and 28-day mortality in patients with septic shock: a retrospective observational study

BACKGROUND

Although the mean arterial pressure (MAP) target of 65 mmHg was achieved, diastolic blood pressure (DBP) was still low in some septic shock patients. The effects of DBP on the prognosis and optimal target for patients with septic shock are unclear. We sought to investigate the relationship between DBP and 28-day mortality in septic shock patients.

METHODS

In this retrospective observational study, we obtained data from the Chinese Database in Intensive Care (CDIC). We included patients with an admission diagnosis of septic shock and shock was controlled. DBP was measured every 1 h, and the mean DBP during the first 24 h (mDBP24h) was recorded. The primary outcome was 28-day mortality. Multivariable logistic regression determined the relationship between mDBP24h and 28-day mortality.

RESULTS

In total, 1251 patients were finally included. The 28-day mortality of included septic shock patients was 28.3%. The mDBP24h, not mSBP24h, was higher among 28-day survivors compared with non-survivors. 28-day mortality was inversely associated with mDBP24h (unadjusted OR 0.814 per 10 mmHg higher mDBP24h, P = 0.003), with a stepwise increase in 28-day mortality at lower mDBP24h. The 28-day mortality of patients with mDBP24h < 59 mmHg had an absolute risk reduction of 9.4% (P = 0.001). And mDBP24h < 59 mmHg was the remaining high risk factor inversely associated with 28-day mortality after multivariable adjustment (adjusted OR 1.915, 95% CI 1.037-3.536, P = 0.038), while mMAP24h and mSBP24h were not.

CONCLUSION

In patients with septic shock after initial resuscitation, we observed an inverse association between mDBP24h and 28-day mortality. The poor outcomes in patients with mDBP24h < 59 mmHg provide indirect evidence supporting a further DBP goal of 59 mmHg for patients with septic shock after MAP of 65 mmHg was achieved.

Early administration of multiple vasopressors is associated with better survival in patients with sepsis: a propensity score-weighted study

BACKGROUND

The association between the timing of administration of multiple vasopressors and patient outcomes has not been investigated.

METHODS

This study used data from the MIMIC-IV database. Patients with sepsis who were administered two or more vasopressors were included. The principal exposure was the last norepinephrine dose when adding a second vasopressor. The cohort was divided into early (last norepinephrine dose < 0.25 μg/kg/min) and normal (last norepinephrine dose ≥ 0.25 μg/kg/min) groups. The primary outcome was 28-day mortality. Multivariable Cox analyses, propensity score matching, stabilized inverse probability of treatment weighting (sIPTW), and restricted cubic spline (RCS) curves were used.

RESULTS

Overall, 1,437 patients who received multiple vasopressors were included. Patients in the early group had lower 28-day mortality (HR: 0.76; 95% CI: 0.65-0.89; p < 0.001) than those in the single group, with similar results in the propensity score-matched (HR: 0.80; 95% CI: 0.68-0.94; p = 0.006) and sIPTW (HR: 0.75; 95% CI: 0.63-0.88; p < 0.001) cohorts. RCS curves showed that the risk of 28-day mortality increased as the last norepinephrine dose increased.

CONCLUSIONS

The timing of secondary vasopressor administration is strongly associated with the outcomes of patients with sepsis.

Fluids and Early Vasopressors in the Management of Septic Shock: Do We Have the Right Answers Yet?

Septic shock is a common condition associated with hypotension and organ dysfunction. It is associated with high mortality rates of up to 60% despite the best recommended resuscitation strategies in international guidelines. Patients with septic shock generally have a Mean Arterial Pressure below 65 mmHg and hypotension is the most important determinant of mortality among this group of patients. The extent and duration of hypotension are important. The two initial options that we have are 1) administration of intravenous (IV) fluids and 2) vasopressors, The current recommendation of the Surviving Sepsis Campaign guidelines to administer 30 ml/kg fluid cannot be applied to all patients. Complications of fluid over-resuscitation further delay organ recovery, prolong ICU and hospital length of stay, and increase mortality. The only reason for administering intravenous fluids in a patient with circulatory shock is to increase the mean systemic filling pressure in a patient who is volume-responsive, such that cardiac output also increases. The use of vasopressors seems to be a more appropriate strategy, the very early administration of vasopressors, preferably during the first hour after diagnosis of septic shock, may have a multimodal action and potential advantages, leading to lower morbidity and mortality in the management of septic patients. Vasopressor therapy should be initiated as soon as possible in patients with septic shock.

Modifications of peripheral perfusion in patients with vasopressor-dependent septic shock treated with polymyxin B-direct hemoperfusion

Abnormal peripheral perfusion (PP) worsens the prognosis of patients with septic shock. Polymyxin B-direct hemoperfusion (PMX-DHP) increases blood pressure and reduces vasopressor doses. However, the modification of PP following administration of PMX-DHP in patients with vasopressor-dependent septic shock have not yet been elucidated. A retrospective exploratory observational study was conducted in patients with septic shock treated with PMX-DHP. Pulse-amplitude index (PAI), vasoactive inotropic score (VIS), and cumulative fluid balance data were extracted at PMX-DHP initiation (T0) and after 24 (T24) and 48 (T48) h. Changes in these data were analyzed in all patients and two subgroups (abnormal PP [PAI < 1] and normal PP [PAI ≥ 1]) based on the PAI at PMX-DHP initiation. Overall, 122 patients (abnormal PP group, n = 67; normal PP group, n = 55) were evaluated. Overall and in the abnormal PP group, PAI increased significantly at T24 and T48 compared with that at T0, with a significant decrease in VIS. Cumulative 24-h fluid balance after PMX-DHP initiation was significantly higher in the abnormal PP group. PMX-DHP may be an effective intervention to improve PP in patients with abnormal PP; however, caution should be exercised as fluid requirements may differ from that of patients with normal PP.

2023 Update on Sepsis and Septic Shock in Adult Patients: Management in the Emergency Department

BACKGROUND

Sepsis/septic shock is a life-threatening and time-dependent condition that requires timely management to reduce mortality. This review aims to update physicians with regard to the main pillars of treatment for this insidious condition.

METHODS

PubMed, Scopus, and EMBASE were searched from inception with special attention paid to November 2021-January 2023.

RESULTS

The management of sepsis/septic shock is challenging and involves different pathophysiological aspects, encompassing empirical antimicrobial treatment (which is promptly administered after microbial tests), fluid (crystalloids) replacement (to be established according to fluid tolerance and fluid responsiveness), and vasoactive agents (e.g., norepinephrine (NE)), which are employed to maintain mean arterial pressure above 65 mmHg and reduce the risk of fluid overload. In cases of refractory shock, vasopressin (rather than epinephrine) should be combined with NE to reach an acceptable level of pressure control. If mechanical ventilation is indicated, the tidal volume should be reduced from 10 to 6 mL/kg. Heparin is administered to prevent venous thromboembolism, and glycemic control is recommended. The efficacy of other treatments (e.g., proton-pump inhibitors, sodium bicarbonate, etc.) is largely debated, and such treatments might be used on a case-to-case basis.

CONCLUSIONS

The management of sepsis/septic shock has significantly progressed in the last few years. Improving knowledge of the main therapeutic cornerstones of this challenging condition is crucial to achieve better patient outcomes.

High-dose vasoactive agents in aeromedical retrievals for septic shock: A role for vasopressin?

OBJECTIVE

To determine the number of patients retrieved by aeromedical teams for septic shock requiring vasopressor support who meet criteria for vasopressin therapy under the Surviving Sepsis Campaign 2021 guidelines.

METHODS

Retrospective chart review of patients transferred by LifeFlight Retrieval Medicine on vasopressors over 2 years.

RESULTS

One thousand one hundred and fifty-eight patients were retrieved on vasopressor therapy, with 428 requiring infusions for septic shock. One hundred and fifteen of these met criteria for administration of vasopressin under Surviving Sepsis Campaign guidelines.

CONCLUSION

A sufficient percentage of patients on vasopressors for septic shock require vasopressin therapy to meet current best treatment guidelines, and the inclusion of vasopressin in retrieval drug kits should be considered by Australian aeromedical services.

Influence of time from admission to norepinephrine administration and volume of fluids received on outcomes of patients meeting sepsis-3 criteria: a retrospective study using the MIMIC-IV database

Objectives

Vasopressors are a cornerstone in the management of sepsis, marked by distributive shock often unresponsive to fluid resuscitation. Prior research and clinician surveys have suggested that earlier usage of vasopressors corresponds to improved outcomes.

Methods

A retrospective cohort was constructed using patient data contained within the Medical Information Mart for Intensive Care-IV database. Analytic cohort included a total of 2079 patients meeting sepsis-3 criteria with a ≥2-point rise in Sequential Organ Failure Assessment score and administered norepinephrine (NE) as first-line vasopressor within 24 hours of admission to the intensive care unit (ICU). Patients receiving other vasopressors or missing documented fluid resuscitation information were excluded. Primary end points included mortality, use of invasive mechanical ventilation and length of stay which were analyzed in a multivariate logistic regression model for the primary effect of time from ICU admission to NE administration using covariates.

Results

Time to NE use was defined as either early, using <6 hours from time of ICU admission or late using >6 hours to ≤24 hours. Patients who received early NE had significantly lower adjusted odds of mortality (0.75, 95% CI 0.57 to 0.97, p=0.026), higher adjusted odds of invasive mechanical ventilation (1.48, 95% CI 1.01 to 2.16, p=0.045), no significant difference in hospital length of stay (difference in days 0.6 (95% CI -3.24 to 2.04)) and lower ICU length of stay (difference in days -0.9 (95% CI -1.74 to -0.01)), as compared with the late NE group.

Conclusion

Among patients admitted to the ICU for sepsis, early use of NE was associated with significantly lower odds of mortality but higher odds of mechanical ventilation, and no significant difference in length of hospital stay but less time in the ICU. Furthermore, the volume of fluids received prior to NE use may have a significant impact on optimal NE timing.

Level of evidence

Level IV-therapeutic care/management.

Modified cardiovascular SOFA score in sepsis: development and internal and external validation

BACKGROUND

The Sepsis-3 criteria introduced the system that uses the Sequential Organ-Failure Assessment (SOFA) score to define sepsis. The cardiovascular SOFA (CV SOFA) scoring system needs modification due to the change in guideline-recommended vasopressors. In this study, we aimed to develop and to validate the modified CV SOFA score.

METHODS

We developed, internally validated, and externally validated the modified CV SOFA score using the suspected infection cohort, sepsis cohort, and septic shock cohort. The primary outcome was 28-day mortality. The modified CV SOFA score system was constructed with consideration of the recently recommended use of the vasopressor norepinephrine with or without lactate level. The predictive validity of the modified SOFA score was evaluated by the discrimination for the primary outcome. Discrimination was assessed using the area under the receiver operating characteristics curve (AUC). Calibration was assessed using the calibration curve. We compared the prognostic performance of the original CV/total SOFA score and the modified CV/total SOFA score to detect mortality in patients with suspected infection, sepsis, or septic shock.

RESULTS

We identified 7,393 patients in the suspected cohort, 4038 patients in the sepsis cohort, and 3,107 patients in the septic shock cohort in seven Korean emergency departments (EDs). The 28-day mortality rates were 7.9%, 21.4%, and 20.5%, respectively, in the suspected infection, sepsis, and septic shock cohorts. The model performance is higher when vasopressor and lactate were used in combination than the vasopressor only used model. The modified CV/total SOFA score was well-developed and internally and externally validated in terms of discrimination and calibration. Predictive validity of the modified CV SOFA was significantly higher than that of the original CV SOFA in the development set (0.682 vs 0.624, p < 0.001), test set (0.716 vs 0.638), and all other cohorts (0.648 vs 0.557, 0.674 vs 0.589). Calibration was modest. In the suspected infection cohort, the modified model classified more patients to sepsis (66.0 vs 62.5%) and identified more patients at risk of septic mortality than the SOFA score (92.6 vs 89.5%).

CONCLUSIONS

Among ED patients with suspected infection, sepsis, and septic shock, the newly-developed modified CV/total SOFA score had higher predictive validity and identified more patients at risk of septic mortality.

Management of sepsis and septic shock in the emergency department

Early management of sepsis and septic shock is crucial for patients' prognosis. As the Emergency Department (ED) is the place where the first medical contact for septic patients is likely to occur, emergency physicians play an essential role in the early phases of patient management, which consists of accurate initial diagnosis, resuscitation, and early antibiotic treatment. Since the issuing of the Surviving Sepsis Campaign guidelines in 2016, several studies have been published on different aspects of sepsis management, adding a substantial amount of new information on the pathophysiology and treatment of sepsis and septic shock. In light of this emerging evidence, the present narrative review provides a comprehensive account of the recent advances in septic patient management in the ED.