Early versus delayed administration of norepinephrine in patients with septic shock

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.

Safety and efficacy of peripheral metaraminol infusion in patients with neurological conditions: a single-center retrospective observational study

Introduction

Metaraminol is a sympathomimetic amine vasopressor that can be administrated through a peripheral venous access. However, limited evidence restricts its application in critically ill patients. This study aimed to investigate the safety and efficacy of peripheral metaraminol infusion in patients with neurological conditions.

Methods

Patients who received peripheral metaraminol infusion between May 2019 and April 2022 were recruited. Data on baseline characteristics, clinical parameters, and infusion-related complications were retrospectively collected and analyzed.

Results

273 patients who received metaraminol were enrolled. Of these, 35 (12.8%) patients required central venous catheter insertion due to inability in achieving hemodynamic stability following peripheral metaraminol monotherapy. In 29,574.2 hours of vasopressor infusion, metaraminol infusion resulted achievement of the target blood pressure 73.4% of the time. Meanwhile, adverse events occurred in 5 patients and resolved after local tissue treatment.

Discussion

Metaraminol could provide hemodynamic support and avoid complications associated with a central venous catheter and delay in vasopressor administration. Through careful and close monitoring, peripheral metaraminol infusion is safe and feasible for patients with neurological conditions. Future large-scale, prospective, multicenter studies are needed to evaluate the safety and efficacy of metaraminol infusion through a peripheral intravenous catheter.

The effect of an intraoperative patient-specific, surgery-specific haemodynamic algorithm in improving textbook outcomes for hepatobiliary-pancreatic surgery: a multicentre retrospective study

Background

The concept of a "textbook outcome" is emerging as a metric for ideal surgical outcomes. We aimed to evaluate the impact of an advanced haemodynamic monitoring (AHDM) algorithm on achieving a textbook outcome in patients undergoing hepatobiliary-pancreatic surgery.

Methods

This retrospective, multicentre observational study was conducted across private and public teaching sectors in Victoria, Australia. We studied patients managed by a patient-specific, surgery-specific haemodynamic algorithm or via usual care. The primary outcome was the effect of using a patient-specific, surgery-specific AHDM algorithm for achieving a textbook outcome, with adjustment using propensity score matching. The textbook outcome criteria were defined according to the International Expert Delphi Consensus on Defining Textbook Outcome in Liver Surgery and Nationwide Analysis of a Novel Quality Measure in Pancreatic Surgery.

Results

Of the 780 weighted cases, 477 (61.2%, 95% CI: 57.7%-64.6%) achieved the textbook outcome. Patients in the AHDM group had a higher rate of textbook outcomes [n = 259 (67.8%)] than those in the Usual care group [n = 218 (54.8%); p < 0.001, estimated odds ratio (95% CI) 1.74 (1.30-2.33)]. The AHDM group had a lower rate of surgery-specific complications, severe complications, and a shorter hospital length of stay (LOS) [OR 2.34 (95% CI: 1.30-4.21), 1.79 (95% CI: 1.12-2.85), and 1.83 (95% CI: 1.35-2.46), respectively]. There was no significant difference between the groups for hospital readmission and mortality.

Conclusions

AHDM use was associated with improved outcomes, supporting its integration in hepatobiliary-pancreatic surgery. Prospective trials are warranted to further evaluate the impact of this AHDM algorithm on achieving a textbook impact on long-term outcomes.

Surviving Sepsis Campaign Research Priorities 2023

OBJECTIVES

To identify research priorities in the management, epidemiology, outcome, and pathophysiology of sepsis and septic shock.

DESIGN

Shortly after publication of the most recent Surviving Sepsis Campaign Guidelines, the Surviving Sepsis Research Committee, a multiprofessional group of 16 international experts representing the European Society of Intensive Care Medicine and the Society of Critical Care Medicine, convened virtually and iteratively developed the article and recommendations, which represents an update from the 2018 Surviving Sepsis Campaign Research Priorities.

METHODS

Each task force member submitted five research questions on any sepsis-related subject. Committee members then independently ranked their top three priorities from the list generated. The highest rated clinical and basic science questions were developed into the current article.

RESULTS

A total of 81 questions were submitted. After merging similar questions, there were 34 clinical and ten basic science research questions submitted for voting. The five top clinical priorities were as follows: 1) what is the best strategy for screening and identification of patients with sepsis, and can predictive modeling assist in real-time recognition of sepsis? 2) what causes organ injury and dysfunction in sepsis, how should it be defined, and how can it be detected? 3) how should fluid resuscitation be individualized initially and beyond? 4) what is the best vasopressor approach for treating the different phases of septic shock? and 5) can a personalized/precision medicine approach identify optimal therapies to improve patient outcomes? The five top basic science priorities were as follows: 1) How can we improve animal models so that they more closely resemble sepsis in humans? 2) What outcome variables maximize correlations between human sepsis and animal models and are therefore most appropriate to use in both? 3) How does sepsis affect the brain, and how do sepsis-induced brain alterations contribute to organ dysfunction? How does sepsis affect interactions between neural, endocrine, and immune systems? 4) How does the microbiome affect sepsis pathobiology? 5) How do genetics and epigenetics influence the development of sepsis, the course of sepsis and the response to treatments for sepsis?

CONCLUSIONS

Knowledge advances in multiple clinical domains have been incorporated in progressive iterations of the Surviving Sepsis Campaign guidelines, allowing for evidence-based recommendations for short- and long-term management of sepsis. However, the strength of existing evidence is modest with significant knowledge gaps and mortality from sepsis remains high. The priorities identified represent a roadmap for research in sepsis and septic shock.

[Guideline-conform treatment of sepsis]

The time to administration of broad-spectrum antibiotics and (secondarily) to the initiation of hemodynamic stabilization are the most important factors influencing survival of patients with sepsis and septic shock; however, the basic prerequisite for the initiation of an adequate treatment is that a suspected diagnosis of sepsis is made first. Therefore, the treatment of sepsis, even before it has begun, is an interdisciplinary and interprofessional task. This article provides an overview of the current state of the art in sepsis treatment and points towards new evidence that has the potential to change guideline recommendations in the coming years. In summary, the following points are critical: (1) sepsis must be diagnosed as soon as possible and the implementation of a source control intervention (in case of a controllable source) has to be implemented as soon as (logistically) possible. (2) In general, intravenous broad-spectrum antibiotics should be given within the first hour after diagnosis if sepsis or septic shock is suspected. In organ dysfunction without shock, where sepsis is a possible but unlikely cause, the results of focused advanced diagnostics should be awaited before a decision to give broad-spectrum antibiotics is made. If it is not clear within 3 h whether sepsis is the cause, broad-spectrum antibiotics should be given when in doubt. Administer beta-lactam antibiotics as a prolonged (or if therapeutic drug monitoring is available, continuous) infusion after an initial loading dose. (3) Combination treatment with two agents for one pathogen group should remain the exception (e.g. multidrug-resistant gram-negative pathogens). (4) In the case of doubt, the duration of anti-infective treatment should rather be shorter than longer. Procalcitonin can support the clinical decision to stop (not to start!) antibiotic treatment! (5) For fluid treatment, if hypoperfusion is present, the first (approximately) 2L (30 ml/kg BW) of crystalloid solution is usually safe and indicated. After that, the rule is: less is more! Any further fluid administration should be carefully weighed up with the help of dynamic parameters, the patient's clinical condition and echo(cardio)graphy.

Use of peripherally inserted central catheters with a dedicated vascular access specialists team versus centrally inserted central catheters in the management of septic shock patients in the ICU

OBJECTIVES

Peripherally inserted central catheters (PICCs) are increasingly recognized as an alternative to centrally inserted central catheters (CICCs) in critical care, yet the data regarding the safety and feasibility of this choice in septic shock management is growing but still lacking. In this study, we aimed to determine the feasibility, safety, and impact on outcomes of using dedicated vascular access specialist (VAS) teams to insert PICCs versus CICCs on patients admitted to the ICU with septic shock.

DESIGN

Retrospective cohort study.

SETTING

Mayo Clinic Rochester Medical ICU and Mayo Clinic Arizona Multidisciplinary ICU from 2013 to 2016.

PATIENTS

All adult patients hospitalized with diagnosis of septic shock excluding patients who declined authorization for review of their medical records, mixed shock states, and readmissions.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

Comprehensive data regarding septic shock diagnosis and resuscitation were abstracted from electronic medical records. A total of 562 patients with septic shock were included in the study; 215 patients were resuscitated utilizing a PICC and 347 were resuscitated using a CICC. On univariate analysis, the time to central line insertion and time to vasopressor initiation were found to be reduced in those who received PICC at time of ICU admission versus CICC. Other favorable outcomes were also observed in those who received PICC versus CICC including shorter ICU length of stay and lower unadjusted hospital mortality. A multivariable analysis for hospital mortality showed that after adjusting for important covariates, neither the time to central line insertion nor the time to vasopressor initiation was associated with a lower hospital mortality.

CONCLUSIONS

Across two tertiary referral centers within the same enterprise, use of a dedicated VAS team for insertion of PICCs for initial resuscitation in patients with septic shock was feasible and associated with shorter time to central venous access and initiation of vasopressors; however, adjusted hospital mortality was not different between the two groups.

Early sepsis in Australia and New Zealand: A point-prevalence study of haemodynamic resuscitation practices

OBJECTIVE

Optimal resuscitation of sepsis-induced hypotension is uncertain, particularly the role of restrictive fluid strategies, leading to variability in usual practice. The objective of this study is to understand resuscitation practices in patients presenting to ED with early sepsis.

METHODS

Design, participants and setting: Prospective, observational, multicentre, single-day, point-prevalence study enrolling adult patients present in 51 Australian and New Zealand ICUs at 10.00 hours, 8 June 2021.

MAIN OUTCOME MEASURES

Site-level data on sepsis policies and patient-level demographic data, presence of sepsis and fluid and vasopressor administration in the first 24 h post-ED presentation.

RESULTS

A total of 722 patients were enrolled. ED was the ICU admission source for 222 of 722 patients (31.2%) and 78 of 222 patients (35%) met the criteria for sepsis within 24 h of ED presentation. Median age of the sepsis cohort was 61 (48-72) years, 58% were male and respiratory infection was the commonest cause (53.8%). The sepsis cohort had a higher severity of illness than the non-sepsis cohort (144/222 patients) and chronic immunocompromise was more common. Of 78 sepsis patients, 55 (71%) received ≥1 fluid boluses with 500 and 1000 mL boluses equally common (both 49%). In the first 24 h, 2335 (1409-3125) mL (25.3 [13.2-42.9] mL/kg) was administered. Vasopressors were administered in 53 of 78 patients (68%) and for 25 patients (47%) administration was peripheral.

CONCLUSIONS

ICU patients presenting to the ED with sepsis receive less fluids than current international recommendations and peripheral vasopressor administration is common. This finding supports the conduct of clinical trials evaluating optimal fluid dose and vasopressor timing for early sepsis-induced hypotension.

INITIATION TIMING OF VASOPRESSOR IN PATIENTS WITH SEPTIC SHOCK: A SYSTEMATIC REVIEW AND META-ANALYSIS

ABSTRACT

Background: Vasopressor plays a crucial role in septic shock. However, the time for vasopressor initiation remains controversial. We conducted a systematic review and meta-analysis to explore its initiation timing for septic shock patients. Methods: PubMed, Cochrane Library, Embase, and Web of Sciences were searched from inception to July 12, 2023, for relevant studies. Primary outcome was short-term mortality. Meta-analysis was performed using Stata 15.0. Results: Twenty-three studies were assessed, including 2 randomized controlled trials and 21 cohort studies. The early group resulted in lower short-term mortality than the late group (OR [95% CI] = 0.775 [0.673 to 0.893], P = 0.000, I2 = 67.8%). The significance existed in the norepinephrine and vasopressin in subgroup analysis. No significant difference was considered in the association between each hour's vasopressor delay and mortality (OR [95% CI] = 1.02 [0.99 to 1.051], P = 0.195, I2 = 57.5%). The early group had an earlier achievement of target MAP ( P < 0.001), shorter vasopressor use duration ( P < 0.001), lower serum lactate level at 24 h ( P = 0.003), lower incidence of kidney injury ( P = 0.001), renal replacement therapy use ( P = 0.022), and longer ventilation-free days to 28 days ( P < 0.001). Conclusions: Early initiation of vasopressor (1-6 h within septic shock onset) would be more beneficial to septic shock patients. The conclusion needs to be further validated by more well-designed randomized controlled trials.

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.

Vasopressin in Sepsis and Other Shock States: State of the Art

This review of the use of vasopressin aims to be comprehensive and highly practical, based on the available scientific evidence and our extensive clinical experience with the drug. It summarizes controversies about vasopressin use in septic shock and other vasodilatory states. Vasopressin is a natural hormone with powerful vasoconstrictive effects and is responsible for the regulation of plasma osmolality by maintaining fluid homeostasis. Septic shock is defined by the need for vasopressors to correct hypotension and lactic acidosis secondary to infection, with a high mortality rate. The Surviving Sepsis Campaign guidelines recommend vasopressin as a second-line vasopressor, added to norepinephrine. However, these guidelines do not address specific debates surrounding the use of vasopressin in real-world clinical practice.

The Timing of Initiating Hydrocortisone and Long-term Mortality in Septic Shock

BACKGROUND

Previous studies on the association between the timing of corticosteroid administration and mortality in septic shock focused only on short-term mortality and produced conflicting results. We performed a retrospective review of a large administrative database of intensive care unit (ICU) patients to evaluate the association between the timing of hydrocortisone initiation and short- and long-term mortality in septic shock. We hypothesized that a longer duration between the first vasopressor use for sepsis and steroid initiation was associated with increased mortality.

METHODS

Data were extracted from the Medical Information Mart in the Intensive Care-IV database. We included adults who met Sepsis-3 definition for septic shock and received hydrocortisone. The exposure of interest was the time in hours from vasopressor use to hydrocortisone initiation (>12 as late and ≤12 as early). The primary outcome was 1-year mortality. Secondary outcomes included 28-day mortality, 90-day mortality, in-hospital mortality, and length of hospital stay. Cox proportional hazard models were used to estimate the association between exposure and mortality. Competing risk regression models were used to evaluate the association between exposure and length of hospital stay.

RESULTS

A total of 844 patients were included in this cohort: 553 in the early group and 291 in the late group. The median time to hydrocortisone initiation was 7 hours (interquartile range, 2.0-19.0 hours). After multivariable Cox proportional hazard analysis, we found that hydrocortisone initiation >12 hours after vasopressor use was associated with increased 1-year mortality when compared with initiation <12 hours (adjusted hazard ratio, 1.39; 95% confidence interval, 1.13-1.71; P = .002, E-value = 2.13). Hydrocortisone initiation >12 hours was also associated with increased 28-day, 90-day, and in-hospital mortality and prolonged length of hospital stay.

CONCLUSIONS

In patients with septic shock, initiating hydrocortisone >12 hours after vasopressor use was associated with an increased risk of both short-term and long-term mortality, and a prolonged length of hospital stay.

Should we initiate vasopressors earlier in patients with septic shock: A mini systemic review

Septic shock treatment remains a major challenge for intensive care units, despite the recent prominent advances in both management and outcomes. Vasopressors serve as a cornerstone of septic shock therapy, but there is still controversy over the timing of administration. Specifically, it remains unclear whether vasopressors should be used early in the course of treatment. Here, we provide a systematic review of the literature on the timing of vasopressor administration. Research was systematically identified through PubMed, Embase and Cochrane searching according to PRISMA guidelines. Fourteen studies met the eligibility criteria and were included in the review. The pathophysiological basis for early vasopressor use was classified, with the exploration on indications for the early administration of mono-vasopressors or their combination with vasopressin or angiotensinII. We found that mortality was 28.1%-47.7% in the early vasopressors group, and 33.6%-54.5% in the control group. We also investigated the issue of vasopressor responsiveness. Furthermore, we acknowledged the subsequent challenge of administration of high-dose norepinephrine via peripheral veins with early vasopressor use. Based on the literature review, we propose a possible protocol for the early initiation of vasopressors in septic shock resuscitation.

Safety and Outcomes of Peripherally Administered Vasopressor Infusion in Patients Admitted with Shock to an Intensive Cardiac Care Unit-A Single-Center Prospective Study

BACKGROUND

Vasopressors are frequently utilized for blood pressure stabilization in patients with cardiogenic shock (CS), although with a questionable benefit. Obtaining central venous access is time consuming and may be associated with serious complications. Hence, we thought to evaluate whether the administration of vasopressors through a peripheral venous catheter (PVC) is a safe and effective alternative for the management of patients with CS presenting to the intensive cardiovascular care unit (ICCU).

METHODS

A prospective single-center study was conducted to compare the safety and outcomes of vasopressors administered via a PVC vs. a central venous catheter (CVC) in patients presenting with CS over a 12-month period.

RESULTS

A total of 1100 patients were included; of them, 139 (12.6%) required a vasopressor treatment due to shock, with 108 (78%) treated via a PVC and 31 (22%) treated via a CVC according to the discretion of the treating physician. The duration of the vasopressor administration was shorter in the PVC group compared with the CVC group (2.5 days vs. 4.2 days, respectively, p < 0.05). Phlebitis and the extravasation of vasopressors occurred at similar rates in the PVC and CVC groups (5.7% vs. 3.3%, respectively, p = 0.33; 0.9% vs. 3.3%, respectively, p = 0.17). Nevertheless, the bleeding rate was higher in the CVC group compared with the PVC group (3% vs. 0%, p = 0.03).

CONCLUSIONS

The administration of vasopressor infusions via PVC for the management of patients with CS is feasible and safe in patients with cardiogenic shock. Further studies are needed to establish this method of treatment.

Hemodynamic management of septic shock: beyond the Surviving Sepsis Campaign guidelines

Although the Surviving Sepsis Campaign guidelines provide standardized and generalized guidance, they are less individualized. This review focuses on recent updates in the hemodynamic management of septic shock. Monitoring and intervention for septic shock should be personalized according to the phase of shock. In the salvage phase, fluid resuscitation and vasopressors should be given to provide life-saving tissue perfusion. During the optimization phase, tissue perfusion should be optimized. In the stabilization and de-escalation phases, minimal fluid infusion and safe fluid removal should be performed, respectively, while preserving organ perfusion. There is controversy surrounding the use of restrictive versus liberal fluid strategies after initial resuscitation. Fluid administration after initial resuscitation should depend upon the patient's fluid responsiveness and requires individualized management. A number of dynamic tests have been proposed to monitor fluid responsiveness, which can help clinicians decide whether to give fluid or not. The optimal timing for the initiation of vasopressor agents is unknown. Recent data suggest that early vasopressor initiation should be considered. Inotropes can be considered in patients with decreased cardiac contractility associated with impaired tissue perfusion despite adequate volume status and arterial blood pressure. Venoarterial extracorporeal membrane oxygenation should be considered for refractory septic shock with severe cardiac systolic dysfunction.

Long-term temporal trends in incidence rate and case fatality of sepsis and COVID-19-related sepsis in Norwegian hospitals, 2008-2021: a nationwide registry study

OBJECTIVES

To estimate temporal trends in incidence rate (IR) and case fatality during a 14-year period from 2008 to 2021, and to assess possible shifts in these trends during the COVID-19 pandemic.

SETTING

All Norwegian hospitals 2008-2021.

PARTICIPANTS

317 705 patients ≥18 year with a sepsis International Classification of Diseases 10th revision code retrieved from The Norwegian Patient Registry.

PRIMARY AND SECONDARY MEASURES

Annual age-standardised IRs with 95% CIs. Poisson regression was used to estimate changes in IRs across time, and logistic regression was used to estimate ORs for in-hospital death.

RESULTS

Among 12 619 803 adult hospitalisations, a total of 317 705 (2.5%) hospitalisations in 222 832 (70.0%) unique patients met the sepsis criteria. The overall age-standardised IR of a first sepsis admission was 246/100 000 (95% CI 245 to 247), whereas the age-standardised IR of all sepsis admissions was 352/100 000 (95% CI 351 to 354). In the period 2009-2019, the annual IR for a first sepsis episode was stable (IR ratio (IRR) per year, 0.999; 95% CI 0.994 to 1.004), whereas for recurrent sepsis the IR increased (annual IRR, 1.048; 95% CI 1.037 to 1.059). During the COVID-19 pandemic, the IRR for a first sepsis was 0.877 (95% CI 0.829 to 0.927) in 2020 and 0.929 (95% CI 0.870 to 0.992) in 2021, and for all sepsis it was 0.870 (95% CI 0.810 to 0.935) in 2020 and 0.908 (95% CI 0.840 to 0.980) in 2021, compared with the previous 11-year period. Case fatality among first sepsis admissions declined in the period 2009-2019 (annual OR 0.954 (95% CI 0.950 to 0.958)), whereas case fatality increased during the COVID-19 pandemic in 2020 (OR 1.061 (95% CI 1.001 to 1.124) and in 2021 (OR 1.164 (95% CI 1.098 to 1.233)).

CONCLUSION

The overall IR of sepsis increased from 2009 to 2019, due to an increasing IR of recurrent sepsis, and indicates that sepsis awareness with updated guidelines and education must continue.

The Eight Unanswered and Answered Questions about the Use of Vasopressors in Septic Shock

Septic shock is mainly characterized-in addition to hypovolemia-by vasoplegia as a consequence of a release of inflammatory mediators. Systemic vasodilatation due to depressed vascular tone results in arterial hypotension, which induces or worsens organ hypoperfusion. Accordingly, vasopressor therapy is mandatory to correct hypotension and to reverse organ perfusion due to hypotension. Currently, two vasopressors are recommended to be used, norepinephrine and vasopressin. Norepinephrine, an α₁-agonist agent, is the first-line vasopressor. Vasopressin is suggested to be added to norepinephrine in cases of inadequate mean arterial pressure instead of escalating the doses of norepinephrine. However, some questions about the bedside use of these vasopressors remain. Some of these questions have been well answered, some of them not clearly addressed, and some others not yet answered. Regarding norepinephrine, we firstly reviewed the arguments in favor of the choice of norepinephrine as a first-line vasopressor. Secondly, we detailed the arguments found in the recent literature in favor of an early introduction of norepinephrine. Thirdly, we reviewed the literature referring to the issue of titrating the doses of norepinephrine using an individualized resuscitation target, and finally, we addressed the issue of escalation of doses in case of refractory shock, a remaining unanswered question. For vasopressin, we reviewed the rationale for adding vasopressin to norepinephrine. Then, we discussed the optimal time for vasopressin administration. Subsequently, we addressed the issue of the optimal vasopressin dose, and finally we discussed the best strategy to wean these two vasopressors when combined.

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.

Effect of Peripherally Infused Norepinephrine on Reducing Central Venous Catheter Utilization

The purpose of this retrospective study was to evaluate the impact of peripherally administered norepinephrine on avoiding central venous catheter insertion while maintaining safety of the infusion. An institutional guideline allows peripheral infusion of norepinephrine via dedicated, 16- to 20-gauge, mid-to-upper arm intravenous (IV) catheters for up to 24 hours. The primary outcome was the need for central venous access in patients initially started on peripherally infused norepinephrine. A total of 124 patients were evaluated (98 initially on peripherally infused norepinephrine vs 26 with central catheter only administration). Thirty-six (37%) of the 98 patients who were started on peripheral norepinephrine avoided the need for central catheter placement, which was associated with $8,900 in direct supply cost avoidance. Eighty (82%) of the 98 patients who started peripherally infused norepinephrine required the vasopressor for ≤12 hours. No extravasation or local complications were observed in any of the 124 patients, regardless of site of infusion. Administration of norepinephrine via a dedicated peripheral IV site appears safe and may lead to a reduction in the need for subsequent central venous access. To achieve timely resuscitation goals, as well as to minimize complications associated with central access, initial peripheral administration should be considered for all patients.

Effect of Early versus Delayed Use of Norepinephrine on Short-Term Outcomes in Patients with Traumatic Hemorrhagic Shock: A Propensity Score Matching Analysis

Background

Guidelines recommend norepinephrine (NE) for the treatment of fatal hypotension caused by trauma. However, the optimal timing of treatment remains unclear.

Objective

We aimed to investigate the effect of early versus delayed use of NE on survival in patients with traumatic haemorrhagic shock (HS).

Materials and Methods

From March 2017 to April 2021, 356 patients with HS in the Department of Emergency Intensive Care Medicine of the Affiliated Hospital of Yangzhou University were identified using the emergency information system and inpatient electronic medical records for inclusion in the study. Our study endpoint was 24 h mortality. We used a propensity score matching (PSM) analysis to reduce bias between groups. Survival models were used to evaluate the relationship between early NE and 24 h survival.

Results

After PSM, 308 patients were divided equally into an early NE (eNE) group and a delayed NE (dNE) group. Patients in the eNE group had lower 24 h mortality rates than those in the dNE group (29.9% versus 44.8%, respectively). A receiver operating characteristic analysis demonstrated that a cut-off point for NE use of 4.4 h yielded optimal predictive value for 24 h mortality, with a sensitivity of 95.52%, a specificity of 81.33% and an area under the curve value of 0.9272. Univariate and multivariate survival analyses showed that the survival rate of patients in the eNE group was higher (p < 0.01) than those in the dNE group.

Conclusion

The use of NE within the first 3 h was associated with a higher 24 h survival rate. The use of eNE appears to be a safe intervention that benefits patients with traumatic HS.

CHARACTERISTICS AND PREDICTORS OF PATIENTS WITH SEPSIS WHO ARE CANDIDATES FOR MINIMALLY INVASIVE APPROACH OUTSIDE OF INTENSIVE CARE UNIT

ABSTRACT

Objective: To identify and describe characteristics of patients with sepsis who could be treated with minimally invasive sepsis (MIS) approach without intensive care unit (ICU) admission and to develop a prediction model to select candidates for MIS approach. Methods: A secondary analysis of the electronic database of patients with sepsis at Mayo Clinic, Rochester, MN. Candidates for the MIS approach were adults with septic shock and less than 48 hours of ICU stay, who did not require advanced respiratory support and were alive at hospital discharge. Comparison group consisted of septic shock patients with an ICU stay of more than 48 hours without advanced respiratory support at the time of ICU admission. Results: Of 1795 medical ICU admissions, 106 patients (6%) met MIS approach criteria. Predictive variables (age >65 years, oxygen flow >4 L/min, temperature <37°C, creatinine >1.6 mg/dL, lactate >3 mmol/L, white blood cells >15 × 10 9 /L, heart rate >100 beats/min, and respiration rate >25 breaths/min) selected through logistic regression were translated into an 8-point score. Model discrimination yielded the area under the receiver operating characteristic curve of 79% and was well fitted (Hosmer-Lemeshow P = 0.94) and calibrated. The MIS score cutoff of 3 resulted in a model odds ratio of 0.15 (95% confidence interval, 0.08-0.28) and a negative predictive value of 91% (95% confidence interval, 88.69-92.92). Conclusions: This study identifies a subset of low-risk septic shock patients who can potentially be managed outside the ICU. Once validated in an independent, prospective sample our prediction model can be used to identify candidates for MIS approach.

Emerging concepts in the care of patients with cirrhosis and septic shock

Septic shock impacts approximately 6% of hospitalized patients with cirrhosis and is associated with high rates of morbidity and mortality. Although a number of landmark clinical trials have paved the way for incremental improvements in the diagnosis and management of septic shock in the general population, patients with cirrhosis have largely been excluded from these studies and critical knowledge gaps continue to impact the care of these individuals. In this review, we discuss nuances in the care of patients with cirrhosis and septic shock using a pathophysiology-based approach. We illustrate that septic shock may be challenging to diagnose in this population in the context of factors such as chronic hypotension, impaired lactate metabolism, and concomitant hepatic encephalopathy. Furthermore, we demonstrate that the application of routine interventions such as intravenous fluids, vasopressors, antibiotics, and steroids should be carefully considered among those with decompensated cirrhosis in light of hemodynamic, metabolic, hormonal, and immunologic disturbances. We propose that future research should include and characterize patients with cirrhosis in a systematic manner, and clinical practice guidelines may need to be refined accordingly.

How I personalize fluid therapy in septic shock?

During septic shock, fluid therapy is aimed at increasing cardiac output and improving tissue oxygenation, but it poses two problems: it has inconsistent and transient efficacy, and it has many well-documented deleterious effects. We suggest that there is a place for its personalization according to the patient characteristics and the clinical situation, at all stages of circulatory failure. Regarding the choice of fluid for volume expansion, isotonic saline induces hyperchloremic acidosis, but only for very large volumes administered. We suggest that balanced solutions should be reserved for patients who have already received large volumes and in whom the chloremia is rising. The initial volume expansion, intended to compensate for the constant hypovolaemia in the initial phase of septic shock, cannot be adapted to the patient's weight only, as suggested by the Surviving Sepsis Campaign, but should also consider potential absolute hypovolemia induced by fluid losses. After the initial fluid infusion, preload responsiveness may rapidly disappear, and it should be assessed. The choice between tests used for this purpose depends on the presence or absence of mechanical ventilation, the monitoring in place and the risk of fluid accumulation. In non-intubated patients, the passive leg raising test and the mini-fluid challenge are suitable. In patients without cardiac output monitoring, tests like the tidal volume challenge, the passive leg raising test and the mini-fluid challenge can be used as they can be performed by measuring changes in pulse pressure variation, assessed through an arterial line. The mini-fluid challenge should not be repeated in patients who already received large volumes of fluids. The variables to assess fluid accumulation depend on the clinical condition. In acute respiratory distress syndrome, pulmonary arterial occlusion pressure, extravascular lung water and pulmonary vascular permeability index assess the risk of worsening alveolar oedema better than arterial oxygenation. In case of abdominal problems, the intra-abdominal pressure should be taken into account. Finally, fluid depletion in the de-escalation phase is considered in patients with significant fluid accumulation. Fluid removal can be guided by preload responsiveness testing, since haemodynamic deterioration is likely to occur in patients with a preload dependent state.

Feasibility of intelligent drug control in the maintenance phase of general anesthesia based on convolutional neural network

Background

The growth and aging process of the human population has accelerated the increase in surgical procedures. Yet, the demand for increasing operations can be hardly met since the training of anesthesiologists is usually a long-term process. Closed-loop artificial intelligence (AI) model provides the possibility to solve intelligent decision-making for anesthesia auxiliary control and, as such, has allowed breakthroughs in closed-loop control of clinical practices in intensive care units (ICUs). However, applying an open-loop artificial intelligence algorithm to build up personalized medication for anesthesia still needs to be further explored. Currently, anesthesiologists have selected doses of intravenously pumped anesthetic drugs mainly based on the blood pressure and bispectral index (BIS), which can express the depth of anesthesia. Unfortunately, BIS cannot be monitored at some medical centers or operational procedures and only be regulated by blood pressure. As a result, here we aim to inaugurally explore the feasibility of a basic intelligent control system applied to drug delivery in the maintenance phase of general anesthesia, based on a convolutional neural network model with open-loop design, according to AI learning of existing anesthesia protocols.

Methods

A convolutional neural network, combined with both sliding window sampling method and residual learning module, was utilized to establish an "AI anesthesiologist" model for intraoperative dosing of personalized anesthetic drugs (propofol and remifentanil). The fitting degree and difference in pumping dose decision, between the AI anesthesiologist and the clinical anesthesiologist, for these personalized anesthetic drugs were examined during the maintenance phase of anesthesia.

Results

The medication level established by the "AI anesthesiologist" was comparable to that obtained by the clinical anesthesiologist during the maintenance phase of anesthesia.

Conclusion

The application of an open-loop decision-making plan by convolutional neural network showed that intelligent anesthesia control is consistent with the actual anesthesia control, thus providing possibility for further evolution and optimization of auxiliary intelligent control of depth of anesthesia.

Balanced Salt Solutions for Critically Ill Patients: Nonplused and Back to Basics

OBJECTIVES

The purpose of this article is to summarize the results of major randomized controlled trials (RCTs) comparing clinical outcomes of critically ill patients treated with normal saline (NS) or balanced salt solutions (BSSs), address discordant results of these studies, and provide direction for future investigations.

DATA SOURCES

PubMed (2011 to January 2022) with bibliographies of retrieved articles searched for additional articles.

STUDY SELECTION AND DATA EXTRACTION

RCTs comparing NS and BSSs in critically ill adult patients.

DATA SYNTHESIS

Recently published large RCTs comparing NS with BSSs in heterogeneous populations of intensive care unit patients did not find significant differences in mortality, despite positive findings in some end points in prior RCTs. However, there were a number of methodologic issues common to the RCTs including: varying study designs and end points, clinician discretion for the majority or all treatments other than the primary intervention fluid, heterogeneous patients with varying levels of acuity, and lack of power to investigate potential subgroup differences. In addition, there were problematic issues related to blinding and use of nonstudy fluids.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Intravenous fluids are a mainstay of supportive care for critically ill patients. Similar to the so-called crystalloid-colloid debate, there has been a long-standing debate among critical care clinicians and researchers concerning the preferred crystalloid solution, NS versus one of the available BSSs.

CONCLUSIONS

Despite the recent publication of large multicenter RCTs, the preferred resuscitation fluid, NS or a BSS, for critically ill patients is still open for debate, although the available investigations do provide some direction for clinicians and for future investigations.

Fluids or vasopressors for the initial resuscitation of septic shock

Intravenous fluid resuscitation is recommended first-line treatment for sepsis-associated hypotension and/or hypoperfusion. The rationale is to restore circulating volume and optimize cardiac output in the setting of shock. Nonetheless, there is limited high-level evidence to support this practice. Over the past decade emerging evidence of harm associated with large volume fluid resuscitation among patients with septic shock has led to calls for a more conservative approach. Specifically, clinical trials undertaken in Africa have found harm associated with initial fluid resuscitation in the setting of infection and hypoperfusion. While translating these findings to practice in other settings is problematic, there has been a re-appraisal of current practice with some recommending earlier use of vasopressors rather than repeated fluid boluses as an alternative to restore perfusion in septic shock. There is consequently uncertainty and variation in practice. The question of fluids or vasopressors for initial resuscitation in septic shock is the subject of international multicentre clinical trials.

An interpretable RL framework for pre-deployment modeling in ICU hypotension management

Computational methods from reinforcement learning have shown promise in inferring treatment strategies for hypotension management and other clinical decision-making challenges. Unfortunately, the resulting models are often difficult for clinicians to interpret, making clinical inspection and validation of these computationally derived strategies challenging in advance of deployment. In this work, we develop a general framework for identifying succinct sets of clinical contexts in which clinicians make very different treatment choices, tracing the effects of those choices, and inferring a set of recommendations for those specific contexts. By focusing on these few key decision points, our framework produces succinct, interpretable treatment strategies that can each be easily visualized and verified by clinical experts. This interrogation process allows clinicians to leverage the model’s use of historical data in tandem with their own expertise to determine which recommendations are worth investigating further e.g. at the bedside. We demonstrate the value of this approach via application to hypotension management in the ICU, an area with critical implications for patient outcomes that lacks data-driven individualized treatment strategies; that said, our framework has broad implications on how to use computational methods to assist with decision-making challenges on a wide range of clinical domains.

Effective hemodynamic monitoring

Hemodynamic monitoring is the centerpiece of patient monitoring in acute care settings. Its effectiveness in terms of improved patient outcomes is difficult to quantify. This review focused on effectiveness of monitoring-linked resuscitation strategies from: (1) process-specific monitoring that allows for non-specific prevention of new onset cardiovascular insufficiency (CVI) in perioperative care. Such goal-directed therapy is associated with decreased perioperative complications and length of stay in high-risk surgery patients. (2) Patient-specific personalized resuscitation approaches for CVI. These approaches including dynamic measures to define volume responsiveness and vasomotor tone, limiting less fluid administration and vasopressor duration, reduced length of care. (3) Hemodynamic monitoring to predict future CVI using machine learning approaches. These approaches presently focus on predicting hypotension. Future clinical trials assessing hemodynamic monitoring need to focus on process-specific monitoring based on modifying therapeutic interventions known to improve patient-centered outcomes.

Adherence to Pediatric Sepsis Treatment Recommendations at Emergency Departments: A Multicenter Study in Latin America

OBJECTIVE

Sepsis is one of the most urgent health care issues worldwide. Guidelines for early identification and treatment are essential to decrease sepsis-related mortality. Our aim was to collect data on the epidemiology of pediatric septic shock (PSS) from the emergency department (PED) and to assess adherence to recommendations for its management in the first hour.

METHODS

A multicenter, prospective, cross-sectional study was conducted evaluating children with PSS seen at the PED of 10 tertiary-care centers in Latin America. Adherence to guidelines was evaluated.

RESULTS

We included 219 patients (median age, 3.7 years); 43% had comorbidities, 31% risk factors for developing sepsis, 74% clinical signs of "cold shock," and 13% of "warm shock," 22% had hypotension on admission. Consciousness was impaired in 55%. A peripheral line was used as initial access in 78% (median placement time, 10 minutes). Fluid and antibiotics infusion was achieved within a median time of 30 minutes (interquartile range [IQR], 20-60 minutes) and 40 minutes (IQR, 20-60 minutes), respectively; 40% responded inadequately to fluids requiring vasoactive drugs (median time at initiation, 60 minutes; IQR, 30-135 minutes). Delay to vasoactive drug infusion was significantly longer when a central line was placed compared to a peripheral line (median time, 133 minutes [59-278 minutes] vs 42 minutes [30-70 minutes], respectively [ P < 0.001]). Adherence to all treatment goals was achieved in 13%. Mortality was 10%. An association between mortality and hypotension on admission was found (26.1% with hypotension vs 4.9% without; P < 0.001).

CONCLUSIONS

We found poor adherence to the international recommendations for the treatment of PSS in the first hour at the PED in third-level hospitals in Latin America.

The pharmacotherapeutic options in patients with catecholamine-resistant vasodilatory shock

INTRODUCTION

Septic and vasoplegic shock are common types of vasodilatory shock (VS) with high mortality. After fluid resuscitation and the use of catecholamine-mediated vasopressors (CMV), vasopressin, angiotensin II, methylene blue (MB) and hydroxocobalamin can be added to maintain blood pressure.

AREAS COVERED

VS treatment utilizes a phased approach with secondary vasopressors added to vasopressor agents to maintain an acceptable mean arterial pressure (MAP). This review covers additional vasopressors and adjunctive therapies used when fluid and catecholamine-mediated vasopressors fail to maintain target MAP.

EXPERT OPINION

Evidence supporting additional vasopressor agents in catecholamine resistant VS is limited to case reports, series, and a few randomized control trials (RCTs) to guide recommendations. Vasopressin is the most common agent added next when MAPs are not adequately supported with CMV. VS patients failing fluids and vasopressors with cardiomyopathy may have cardiotonic agents such as dobutamine or milrinone added before or after vasopressin. Angiotensin II, another class of vasopressor is used in VS to maintain adequate MAP. MB and/or hydoxocobalamin, vitamin C, thiamine and corticosteroids are adjunctive therapies used in refractory VS. More RCTs are needed to confirm the utility of these drugs, at what doses, which combinations and in what order they should be given.

Vasopressor Administration via Peripheral Intravenous Access for Emergency Department Stabilization in Septic Shock Patients

Background

Septic shock is commonly treated in the emergency department (ED) with vasopressors. Prior data have shown that vasopressor administration through a peripheral intravenous line (PIV) is feasible.

Objectives

To characterize vasopressor administration for patients presenting to an academic ED in septic shock.

Materials and methods

Retrospective observational cohort study evaluating initial vasopressor administration for septic shock. ED patients from June 2018 to May 2019 were screened. Exclusion criteria included other shock states, hospital transfers, or heart failure history. Patient demographics, vasopressor data, and length of stay (LOS) were collected. Cases were grouped by initiation site: PIV, ED placed central line (ED-CVL), or tunneled port/indwelling central line (Prior-CVL).

Results

Of the 136 patients identified, 69 were included. Vasopressors were initiated via PIV in 49%, ED-CVL in 25%, and prior-CVL in 26%. The time to initiation was 214.8 minutes in PIV and 294.7 minutes in ED-CVL (p = 0.240). Norepinephrine predominated all groups. No extravasation or ischemic complications were identified with PIV vasopressor administration. Twenty-eight-day mortality was 20.6% for PIV, 17.6% for ED-CVL, and 61.1% for prior-CVL. Of 28-day survivors, ICU LOS was 4.44 for PIV and 4.86 for ED-CVL (p = 0.687), while vasopressor days were 2.26 for PIV and 3.14 for ED-CVL (p = 0.050).

Conclusion

Vasopressors are being administered via PIVs for ED septic shock patients. Norepinephrine comprised the majority of initial PIV vasopressor administration. There were no documented episodes of extravasation or ischemia. Further studies should look at the duration of PIV administration with potential avoidance of central venous cannulation altogether in appropriate patients.

How to cite this article

Kilian S, Surrey A, McCarron W, Mueller K, Wessman BT. Vasopressor Administration via Peripheral Intravenous Access for Emergency Department Stabilization in Septic Shock Patients. Indian J Crit Care Med 2022;26(7):811-815.

Utilisation of peripheral vasopressor medications and extravasation events among critically ill patients in Rwanda: A prospective cohort study

Introduction

In high-income settings, vasopressor administration to treat haemodynamic instability through a central venous catheter (CVC) is the preferred standard. However, due to lack of availability and potential for complications, CVCs are not widely used in low- and middle-income countries. This prospective cohort study evaluated the use of peripheral vasopressors and associated incidence of extravasation events in patients with haemodynamic instability at the Centre Hospitalier Universitaire Kigali, Rwanda.

Methods

Patients ≥18 years of age receiving peripheral vasopressors in the emergency centre (EC) or intensive care unit (ICU) for >1 hour were eligible for inclusion. The primary outcome was extravasation events. Patients were followed hourly until extravasation, medication discontinuation, death, or CVC placement. Extravasation incidence with 95% confidence intervals (CI) were calculated using Poisson exact tests.

Results

64 patients were analysed. The median age was 49 (Interquartile Range [IQR]:33-65) and 55% were female. Distributive shock was the most frequent aetiology (47%). Intravenous (IV) location was most commonly antecubital fossa/upper arm (31%) and forearm/hand (43%). IV gauges ≤18 were used in 58% of locations. Most patients were treated with adrenaline (66%) and noradrenaline (41%), and 11% received multiple vasopressors. The median treatment duration was 19 hours (IQR:8.5-37). Treatment discontinuation was predominantly due to mortality (41%) or resolution of instability (36%). There were two extravasation events (2.9%), both limited to soft tissue swelling. Extravasation incidence was 0.8 events per 1000 patient-hours (95% CI:0.2-2.2).

Conclusion

Extravasation incidence with peripheral vasopressors was low, even with long use durations, suggesting peripheral infusions may be an acceptable approach when barriers exist to CVC placement.

Vasopressors in Septic Shock: The Quest for Refinement

How to cite this article: Pichamuthu K. Vasopressors in Septic Shock: The Quest for Refinement. Indian J Crit Care Med 2022;26(6):659–660.

Timing of vasoactive agents and corticosteroid initiation in septic shock

Septic shock remains a health care concern associated with significant morbidity and mortality. The Surviving Sepsis Campaign Guidelines for Management of Sepsis and Septic Shock recommend early fluid resuscitation and antimicrobials. Beyond initial management, the guidelines do not provide clear recommendations on appropriate time to initiate vasoactive therapies and corticosteroids in patients who develop shock. This review summarizes the literature regarding time of initiation of these interventions. Clinical data regarding time of initiation of these therapies in relation to shock onset, sequence of treatments with regard to each other, and clinical markers evaluated to guide initiation are summarized. Early-high vasopressor initiation within first 6 h of shock onset is associated with lower mortality. Following norepinephrine initiation, the exact dose and timing of escalation to adjunctive vasopressor agents are not well elucidated in the literature. However, recent data indicate that timing may be an important factor in initiating vasopressors and adjunctive therapies, such as corticosteroids. Norepinephrine-equivalent dose and lactate concentration can aid in determining when to initiate vasopressin and angiotensin II in patients with septic shock. Future guidelines with clear recommendations on the time of initiation of septic shock therapies are warranted.

Pathophysiology, mechanisms, and managements of tissue hypoxia

Oxygen is needed to generate aerobic adenosine triphosphate and energy that is required to support vital cellular functions. Oxygen delivery (DO₂) to the tissues is determined by convective and diffusive processes. The ability of the body to adjust oxygen extraction (ERO₂) in response to changes in DO₂ is crucial to maintain constant tissue oxygen consumption (VO₂). The capability to increase ERO₂ is the result of the regulation of the circulation and the effects of the simultaneous activation of both central and local factors. The endothelium plays a crucial role in matching tissue oxygen supply to demand in situations of acute drop in tissue oxygenation. Tissue oxygenation is adequate when tissue oxygen demand is met. When DO₂ is severely compromised, a critical DO₂ value is reached below which VO₂ falls and becomes dependent on DO₂, resulting in tissue hypoxia. The different mechanisms of tissue hypoxia are circulatory, anaemic, and hypoxic, characterised by a diminished DO₂ but preserved capacity of increasing ERO₂. Cytopathic hypoxia is another mechanism of tissue hypoxia that is due to impairment in mitochondrial respiration that can be observed in septic conditions with normal overall DO₂. Sepsis induces microcirculatory alterations with decreased functional capillary density, increased number of stopped-flow capillaries, and marked heterogeneity between the areas with large intercapillary distance, resulting in impairment of the tissue to extract oxygen and to satisfy the increased tissue oxygen demand, leading to the development of tissue hypoxia. Different therapeutic approaches exist to increase DO₂ and improve microcirculation, such as fluid therapy, transfusion, vasopressors, inotropes, and vasodilators. However, the effects of these agents on microcirculation are quite variable.

Prehospital norepinephrine administration reduces 30-day mortality among septic shock patients

Background

Despite differences in time of sepsis recognition, recent studies support that early initiation of norepinephrine in patients with septic shock (SS) improves outcome without an increase in adverse effects. This study aims to investigate the relationship between 30-day mortality in patients with SS and prehospital norepinephrine infusion in order to reach a mean blood pressure (MAP) > 65 mmHg at the end of the prehospital stage.

Methods

From April 06th, 2016 to December 31th, 2020, patients with SS requiring prehospital Mobile Intensive Care Unit intervention (MICU) were retrospectively analysed. To consider cofounders, the propensity score method was used to assess the relationship between prehospital norepinephrine administration in order to reach a MAP > 65 mmHg at the end of the prehospital stage and 30-day mortality.

Results

Four hundred and seventy-eight patients were retrospectively analysed, among which 309 patients (65%) were male. The mean age was 69 ± 15 years. Pulmonary, digestive, and urinary infections were suspected among 44%, 24% and 17% patients, respectively. One third of patients (n = 143) received prehospital norepinephrine administration with a median dose of 1.0 [0.5–2.0] mg h⁻¹, among which 84 (69%) were alive and 38 (31%) were deceased on day 30 after hospital-admission. 30-day overall mortality was 30%. Cox regression analysis after the propensity score showed a significant association between prehospital norepinephrine administration and 30-day mortality, with an adjusted hazard ratio of 0.42 [0.25–0.70], p < 10^–3. Multivariate logistic regression of IPTW retrieved a significant decrease of 30-day mortality among the prehospital norepinephrine group: ORa = 0.75 [0.70–0.79], p < 10^–3.

Conclusion

In this study, we report that prehospital norepinephrine infusion in order to reach a MAP > 65 mmHg at the end of the prehospital stage is associated with a decrease in 30-day mortality in patients with SS cared for by a MICU in the prehospital setting. Further prospective studies are needed to confirm that very early norepinephrine infusion decreases septic shock mortality.

[Vasoactive drugs in the treatment of septic shock]

Septic shock is a high mortality complication frequently associated with sepsis. Early initiation of vasopressor treatment, even before completion of initial fluid resuscitation, is a determining factor in prognosis. In this sense, norepinephrine continues to be the drug of first choice, although there is increasing evidence of benefit combining it with other non-adrenergic drugs, such as vasopressin, instead of escalating norepinephrine doses. The pathophysiology of septic shock is multifactorial, and sometimes is associated with a situation of myocardial dysfunction that contributes to hemodynamic instability. It is essential to identify this situation since it worsens the prognosis and may benefit from combined treatment with inotropic drugs. There are novel vasoactive agents under study, more selective than the classic ones that in a next future could help to design more individualized and precise treatments. In the present work, the current knowledge about vasoactive drugs and their use in the management of septic shock is summarized according to the most recent scientific evidence.

Safety of Vasopressor Medications through Peripheral Line in Pediatric Patients in PICU in a Resource-Limited Setting

Objective

Central venous catheter (CVC) placement in children in resource-limited settings (RLSs) can be a difficult task. Timely administration of vasopressor medications (VMs) through peripheral intravenous line (PIV) can help overcome this limitation. We aim to determine the safety of administration of vasopressor medications through PIVs in children admitted to pediatric intensive care unit (PICU) in a RLS.

Design

Prospective observational study. Setting. An eight-bedded PICU of a tertiary care hospital. Patients. Children aged 1 month to 18 years admitted to the PICU. Intervention. None. Measurements and Main Results. All children (aged 1 month–18 years) who received VMs through PIV line from January 2019 to December 2019 were prospectively followed for the development of extravasation, conversion to CVC, duration of infusion, maximum dose of VMs used, maximum vasopressor inotropic score (VIS), and coadministration of vasopressor medication through PIV line. Results are presented as means with standard deviation and frequency with percentages. A total of 369 patients were included in the study, 221 (59.9%) were males, and the median age of the study population was 24 months (IQR; 6–96). Epinephrine was the most frequently used vasopressor medication (n = 279, 75.6%), followed by milrinone (n = 93, 25.2%), norepinephrine (n = 42, 11.4%), and dopamine (n = 32, 8.7%). The maximum dose of vasopressor medication was 0.25 µg/kg/min (epinephrine), 0.2 µg/kg/min (norepinephrine), 15 µg/kg/min (dopamine), and 0.8 µg/kg/min (milrinone). Extravasation was observed in 8 (2.2%) patients, while PIV line was converted to CVC in 127 (34.4%) children. Maximum dose of epinephrine, norepinephrine, VIS score, and PRISM Score was associated with conversion to CVC (p < 0.001), while none of them was associated with risk for extravasation.

Conclusion

Vasopressor medication through PIV line is a safe option in patients admitted to the PICU.

Vasopressor Choice and Timing in Vasodilatory Shock

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2022. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2022 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from https://link.springer.com/bookseries/8901 .

A Standardized Step-by-Step Approach for the Diagnosis and Treatment of Sepsis

Sepsis is the major culprit of death among critically ill patients who are hospitalized in intensive care units (ICUs). Although sepsis-related mortality is steadily declining year-by-year due to the continuous understanding of the pathophysiological mechanism on sepsis and improvement of the bundle treatment, sepsis-associated hospitalization is rising worldwide. Surviving Sepsis Campaign (SSC) guidelines are continuously updating, while their content is extremely complex and comprehensive for a precisely implementation in clinical practice. As a consequence, a standardized step-by-step approach for the diagnosis and treatment of sepsis is particularly important. In the present study, we proposed a standardized step-by-step approach for the diagnosis and treatment of sepsis using our daily clinical experience and the latest researches, which is close to clinical practice and is easy to implement. The proposed approach may assist clinicians to more effectively diagnose and treat septic patients and avoid the emergence of adverse clinical outcomes.

Influence of Timing and Catecholamine Requirements on Vasopressin Responsiveness in Critically ill Patients with Septic Shock

Introduction: Despite its widespread use, there is a paucity of data to guide the optimal use of arginine vasopressin (AVP) in critically ill patients with septic shock. Methods: This multicenter retrospective cohort study conducted in critically ill adults sought to evaluate the role of catecholamine requirements and timing on responsiveness to AVP. Responsiveness was defined as both a decrease in ≥ 50% of catecholamine requirements and no decrease in mean arterial pressure (MAP) at 4 hours post-AVP initiation. Primary outcomes of interest included the proportion of patients who started AVP within 4 hours after starting catecholamine therapy, as well as baseline norepinephrine (NE) equivalents (< 15, 15-39, or ≥ 40 mcg/min). Multivariate analyses and logistic regression were performed to identify other factors associated with AVP responsiveness. Results: There were 300 patients included in this study, with 74 patients being responders and 226 being non-responders. There was no significant difference in the number of patients who received AVP within 4 hours from catecholamine initiation between responders and non-responders (35% vs. 42%, P = 0.29). There were more patients in the non-responder group requiring ≥ 40 mcg/min of NE equivalents at AVP initiation (30% vs. 16%, P = 0.023). Stress dose steroid use was less common in responders (35% vs. 52%, P = 0.011), which was consistent with logistic regression analysis (OR 0.56, 95% 0.32-0.98, P = 0.044). Clinical outcomes between responders and non-responders were similar, apart from ICU (5.4% vs. 19.5%) and hospital (5.4% vs. 20.4%) mortality being lower in responders (P = 0.0032 and P = 0.0002, respectively). Conclusion: Shorter times to AVP initiation was not associated with responsiveness at 4 hours post-catecholamine initiation, although non-responders tended to require higher doses of NE equivalents at time of AVP initiation. Concomitant corticosteroids were associated with a lower likelihood of AVP responsiveness.

Use of Inotropics by Peripheral Vascular Line in the First Hour of Treatment of Pediatric Septic Shock: Experience at an Emergency Department

OBJECTIVE

Mortality in pediatric septic shock remains unacceptably high. Delays in vasopressor administration have been associated with an increased risk of mortality. Current treatment guidelines suggest the use of a peripheral vascular line (PVL) for inotropic administration in fluid-refractory septic shock when a central vascular line is not already in place. The aim of this study was to report local adverse effects associated with inotropic drug administration through a PVL at a pediatric emergency department setting in the first hour of treatment of septic shock.

METHODS

A prospective, descriptive, observational cohort study of patients with septic shock requiring PVL inotropic administration was conducted at the pediatric emergency department of a tertiary care pediatric hospital. For the infusion and postplacement care of the PVL for vasoactive drugs, an institutional nursing protocol was used.

RESULTS

We included 49 patients; 51% had an underlying disease. Eighty-four percent of the children included had a clinical "cold shock." The most frequently used vasoactive drug was epinephrine (72%). One patient presented with local complications.

CONCLUSIONS

At our center, infusion of vasoactive drugs through a PVL was shown to be safe and allowed for adherence to the current guidelines for pediatric septic shock.

Major Publications in the Critical Care Pharmacotherapy Literature: 2020

OBJECTIVES

To summarize selected meta-analyses and trials related to critical care pharmacotherapy published in 2020.

DATA SOURCES

The Clinical Pharmacy and Pharmacology Pharmacotherapy Literature Update group screened 36 journals monthly for impactful publications.

STUDY SELECTION

The group reviewed a total of 119 articles during 2020 according to relevance for practice.

DATA EXTRACTION

Articles were selected with consensus and importance to clinical practice from those included in the monthly Clinical Pharmacy and Pharmacology Pharmacotherapy Literature Update. The group reviewed articles according to Grading of Recommendations, Assessment, Development, and Evaluations criteria. Articles with a 1A grade were selected.

DATA SYNTHESIS

Several trials were summarized, including two meta-analyses and five original research trials. Original research trials evaluating vitamin C, hydrocortisone, and thiamine versus hydrocortisone in sepsis, the use of nonsedation strategies, dexmedetomidine in cardiac surgery, remdesivir for severe acute respiratory syndrome coronavirus 2, and thrombectomy in acute ischemic stroke. Two meta-analyses determining the impact of norepinephrine initiation in patients with septic shock and the use of corticosteroids in severe acute respiratory syndrome coronavirus 2 was included.

CONCLUSIONS

This clinical review provides summary and perspectives of clinical practice impact on influential critical care pharmacotherapy publications in 2020.

Hemodynamic resuscitation with fluids bolus and norepinephrine increases severity of lung damage in an experimental model of septic shock

OBJECTIVE

Hemodynamic resuscitation is considered a cornerstone of the initial treatment of septic shock. However, there is growing concern about its side effects. Our objective was to assess the relationship between fluid administration and norepinephrine infusion and the development of lung injury.

DESIGN

Randomized in vivo study in rabbits.

SETTING

University animal research laboratory.

PATIENTS

Eighteen New Zealand rabbits. Control group (SHAM, n=6), Sepsis group with or without hemodynamic resuscitation (ETX-R, n=6; ETX-NR, n=6).

INTERVENTIONS

Sepsis was induced by intravenous lipopolysaccharide administration and animals were followed-up for 4h. Hemodynamic resuscitation with Ringer lactate (20mL·kg^-1) was administered and later norepinephrine was initiated 3h after sepsis induction. At the end, the left lung was excised.

MAIN VARIABLES OF INTEREST

An indwelling arterial catheter and an esophageal Doppler were placed. Lung mechanics were monitored with side stream spirometry. Lung damage was analyzed by histopathological examination.

RESULTS

The SHAM group did not show hemodynamic or respiratory changes. Lipopolysaccharide administration aimed an increase in cardiac output and arterial hypotension. In the ETX-NR group, animals remained hypotensive until the end of the experiment. Resuscitation with fluids and norepinephrine reversed arterial hypotension. Compared to the ETX-NR group, the remaining lung of the ETX-R group showed greater accumulation of neutrophils and reactive type-II pneumocytes, thicker alveolar wall, alveolar hemorrhage and non-aerated pulmonary areas. Lung injury score was larger in the ETX-R group.

CONCLUSIONS

In our experimental study, following a strategy with bolus fluids and late norepinephrine used in the early phase of endotoxic septic shock has a negative influence on the development of lung injury.

Combining fluids and vasopressors: A magic potion?

Early detection and prompt reversal of sepsis-induced tissue hypoperfusion are key elements while treating patients with septic shock. Fluid administration is widely accepted as the first-line therapy followed by vasopressor use in persistently hypotensive patients or in those with insufficient arterial pressure to ensure adequate tissue perfusion. Recent evidence suggests a beneficial effect of combining fluids with vasopressors in the early phase of sepsis. Compared with fluids alone, combining fluids and vasopressors increases mean systemic pressure and venous return and corrects hypotension better. This approach also limits fluid overload, which is an independent factor of poor outcomes in sepsis. It produces less hemodilution than fluids alone. As a consequence of these effects, combined treatment may improve outcomes in septic shock patients.