Vasopressor Therapy in the Intensive Care Unit

Management of the acute on chronic liver failure in the intensive care unit

Acute on chronic liver failure (ACLF) reflects the development of organ failure(s) in a patient with cirrhosis and is associated with high short-term mortality. Given that ACLF has many different 'phenotypes', medical management needs to take into account the relationship between precipitating insult, organ systems involved and underlying physiology of chronic liver disease/cirrhosis. The goals of intensive care management of patients suffering ACLF are to rapidly recognize and treat inciting events (e.g. infection, severe alcoholic hepatitis and bleeding) and to aggressively support failing organ systems to ensure that patients may successfully undergo liver transplantation or recovery. Management of these patients is complex since they are prone to develop new organ failures and infectious or bleeding complications. ICU therapy parallels that applied in the general ICU population in some complications but differs in others. Given that liver transplantation in ACLF is an emerging and evolving field, multidisciplinary teams with expertise in critical care and transplant medicine best accomplish management of the critically ill ACLF patient. The focus of this review is to identify the common complications of ACLF and to describe the proper management in critically ill patients awaiting liver transplantation in our centres, including organ support, prognostic assessment and how to assess when recovery is unlikely.

Longitudinal trend in post-discharge estimated glomerular filtration rate in intensive care survivors

Background

Acute kidney injury (AKI) within the intensive care unit (ICU) is common but evidence is limited on longer-term renal outcomes. We aimed to model the trend of kidney function in ICU survivors using estimated glomerular filtration rate (eGFR), comparing those with and without AKI, and investigate potential risk factors associated with eGFR decline.

Methods

This observational cohort study included all patients aged 16 or older admitted to two general adult ICUs in Scotland between 1st July 2015 and 30th June 2018 who survived to 30 days following hospital discharge. Baseline serum creatinine and subsequent values were used to identify patients with AKI and calculate eGFR following hospital discharge. Mixed effects modelling was used to control for repeated measures and to allow inclusion of several exploratory variables.

Results

3649 patients were included, with 1252 (34%) experiencing in-ICU AKI. Patients were followed up for up to 2000 days with a median 21 eGFR measurements. eGFR declined at a rate of -1.9 ml/min/1.73m2/year (p-value < 0.001) in the overall ICU survivor cohort. Patients with AKI experienced an accelerated rate of post-ICU eGFR decline of -2.0 ml/min/1.73m2/year compared to a rate of -1.83 ml/min/1.73m2/year in patients who did not experience AKI (p-value 0.007). Pre-existing diabetes or liver disease and in-ICU vasopressor support were associated with accelerated eGFR decline regardless of AKI experience.

Conclusions

ICU survivors experienced a decline in kidney function beyond that which would be expected regardless of in-ICU AKI. Long-term follow-up is warranted in ICU survivors to monitor kidney function and reduce morbidity and mortality.

Lactate level is an independent predictor of mortality in patients with hematologic malignancy receiving urgent chemotherapy in intensive care unit

BACKGROUND

Intensive care unit (ICU) survival of cancer patients has improved. Urgent chemotherapy has become feasible in critically ill patients with specific organ dysfunction due to hematological malignancies.

OBJECTIVE

The aim of the study was to assess ICU mortality rates and the factors associated with mortality in patients with hematologic malignancies receiving urgent chemotherapy in the ICU.

METHODS

We retrospectively included all patients admitted to the ICU who received chemotherapy due to hematologic malignancy in 2012-2022.

RESULTS

Of the 129 patients undergoing chemotherapy in the ICU, 50 (38.7 %) died during the ICU follow-up. The following conditions were significantly more common among nonsurvivors: presence of infection at the time of ICU admission (p < 0.001), the requirement for mechanical ventilation during ICU stay (p < 0.001), the need for noninvasive mechanical ventilation during ICU stay (p = 0.014), vasopressor support (p < 0.001), and sepsis (p < 0.001). Logistic regression analysis revealed that among laboratory parameters on ICU admission, lactate (p = 0.008), albumin (p = 0.022), C-reactive protein (p = 0.046), baseline sequential organ failure assessment (SOFA) score (p < 0.001), newly developed heart failure (p = 0.006), and the requirement for vasopressor agents during ICU stay (p < 0.001) significantly influenced the risk of mortality in the univariate analysis. The multivariate analysis revealed lactate levels (p = 0.047) on ICU admission as an independent predictor of mortality.

CONCLUSION

The development of heart failure and lactate levels on admission were the main predictors of mortality. Additionally, higher SOFA scores revealed that illness severity was closely associated with mortality. Future studies should focus on strategies to further reduce these risks and achieve the best outcomes for these patients.

Ten take-home messages on vasopressin use in critically ill patients

The most used vasopressors in critically ill patients are exogenous catecholamines, mainly norepinephrine. Their use can be associated with serious adverse events and even increased mortality, especially if administered at high doses. In recent years, the addition of vasopressin has been proposed to counteract the deleterious effects of high doses of catecholamines (decatecholaminization) with the intention of improving the prognosis of these patients. Currently, vasopressin has two main indications: septic shock and vasoplegic shock in the postoperative period of cardiac surgery. In septic shock, current evidence favors its early initiation before reaching high doses of norepinephrine. In the postoperative period of cardiac surgery, the different benefits of the use of vasopressin have been studied, especially in patients with atrial fibrillation and pulmonary hypertension. When used properly, vasopressin is a safe an effective drug for the indications described above.

Timing of adjunctive vasopressin initiation for septic shock patients and hospital mortality: A multicentre observational study

Objective

The optimal timing of vasopressin initiation as an adjunctive vasopressor remains unclear. We aimed to study the association between the timing of vasopressin commencement, pre-specified physiological parameters, and hospital mortality.

Design

We conducted a multicentre, retrospective, observational study.

Setting

Twelve ICUs in Queensland, Australia between January 2015 and December 2021.

Participants

Adult patients with septic shock who received vasopressin as an adjunctive vasopressor within 72 hours of ICU admission.

Main Outcome

Hospital mortality.

Results

Overall, 2747 patients fulfilled the inclusion criteria. Of these, 1850 (67%) started vasopressin within six hours of vasopressor therapy start, while 897 (33%) started vasopressin between six hours and 72 hours. APACHE III score, peak lactate, and creatinine were higher in the early start group. Early vasopressin start was independently associated with decreased hospital mortality (aOR = 0.69, 95% CI = 0.57-0.83). Vasopressin infusion start was also associated with an immediate decrease in the noradrenaline-equivalent dose regardless of timing. There was a statistically significant favourable breakpoint at vasopressin start for the course of arterial pH, lactate, heart rate and crystalloid infusion rate (p<0.001).

Conclusions

In patients with septic shock, early adjunctive vasopressin initiation was independently associated with lower hospital mortality. Vasopressin starting at any time was also associated with reduced tachycardia, acidosis, and hyperlactatemia.

Perioperative hypotension and use of vasoactive agents in non-cardiac surgery: A scoping review

BACKGROUND

Perioperative hypotension is common and associated with adverse patient outcomes. Vasoactive agents are often used to manage hypotension, but the ideal drug, dose and duration of treatment has not been established. With this scoping review, we aim to provide an overview of the current body of evidence regarding the vasoactive agents used to treat perioperative hypotension in non-cardiac surgery.

METHODS

We included all studies describing the use of vasoactive agents for the treatment of perioperative hypotension in non-cardiac surgery. We excluded literature reviews, case studies, and studies on animals and healthy subjects. We posed the following research questions: (1) in which surgical populations have vasoactive agents been studied? (2) which agents have been studied? (3) what doses have been assessed? (4) what is the duration of treatment? and (5) which desirable and undesirable outcomes have been assessed?

RESULTS

We included 124 studies representing 10 surgical specialties. Eighteen different agents were evaluated, predominantly phenylephrine, ephedrine, and noradrenaline. The agents were administered through six different routes, and numerous comparisons between agents, dosages and routes were included. Then, 88 distinct outcome measures were assessed, of which 54 were judged to be non-patient-centred.

CONCLUSIONS

We found that studies concerning vasoactive agents for the treatment of perioperative hypotension varied considerably in all aspects. Populations were heterogeneous, interventions and exposures included multiple agents compared against themselves, each other, fluids or placebo, and studies reported primarily non-patient-centred outcomes.

Transplantation, bridging, and support technologies in pulmonary hypertension

Despite the progress made in medical therapies for treating pulmonary hypertension (PH), a subset of patients remain susceptible to developing a maladaptive right ventricular phenotype. The effective management of end-stage PH presents substantial challenges, necessitating a multidisciplinary approach and early identification of patients prone to acute decompensation. Identifying potential transplant candidates and assessing the feasibility of such a procedure are pivotal tasks that should be undertaken early in the treatment algorithm. Inclusion on the transplant list is contingent upon a comprehensive risk assessment, also considering the specific type of PH and various factors affecting waiting times, all of which should inform the decision-making process. While bilateral lung transplantation is the preferred option, it demands expert intra- and post-operative management to mitigate the heightened risks of pulmonary oedema and primary graft dysfunction in PH patients. Despite the availability of risk assessment tools, the occurrence of acute PH decompensation episodes can be unpredictable, potentially leading to refractory right ventricular failure even with optimal medical intervention, necessitating the use of rescue therapies. Advancements in right ventricular assist techniques and adjustments to graft allocation protocols for the most critically ill patients have significantly enhanced the survival in intensive care, affording the opportunity to endure while awaiting an urgent transplant. Given the breadth of therapeutic options available, specialised centres capable of delivering comprehensive care have become indispensable for optimising patient outcomes. These centres are instrumental in providing holistic support and management tailored to the complex needs of PH patients, ultimately enhancing their chances of a successful transplant and improved long-term prognosis.

Management of Sepsis in the First 24 Hours: Bundles of Care and Individualized Approach

Early diagnosis and prompt management are essential to enhance the outcomes of patients with sepsis and septic shock. Over the past two decades, evidence-based guidelines have guided appropriate treatment and recommended the implementation of a bundle strategy to deliver fundamental treatments within the initial hours of care. Shortly after its introduction, the implementation of a bundle strategy has led to a substantial decrease in mortality rates across various health care settings. The primary advantage of these bundles is their universality, making them applicable to all patients with sepsis. However, this same quality also represents their primary disadvantage as it fails to account for the significant heterogeneity within the septic patient population. Recently, the individualization of treatments included in the bundle has been suggested as a potential strategy for further improving the prognosis of patients with sepsis. New strategies for the early identification of microorganisms and their resistance patterns, advanced knowledge of antibiotic kinetics in critically ill patients, more conservative fluid therapy in specific patient populations, and early use of alternative vasopressors to catecholamines, as well as tailored source control based on patient conditions and site of infection, are potential approaches to personalize initial care for specific subgroups of patients. These innovative methodologies have the potential to improve the management of septic shock. However, their implementation in clinical practice should be guided by solid evidence. Therefore, it is imperative that future research evaluate the safety, efficacy, and cost-effectiveness of these strategies.

Transient Diabetes Insipidus After Vasopressin Discontinuation

Vasopressin infusion is commonly used in intensive care settings during states of advanced vasodilatory shock for its vasoconstrictive properties. Vasopressin also acts on renal tubular cell receptors in the collecting ducts of kidneys to allow for water reabsorption. The sudden discontinuation of vasopressin infusion can lead to the development of transient diabetes insipidus (DI) with classic findings of polyuria, dilute urine, and hypernatremia. We report the case of a 59-year-old male who underwent an emergent bedside cricothyrotomy procedure secondary to papillary carcinoma of the thyroid and subsequently developed septic shock requiring initiation of vasopressin infusion for hemodynamic support. He remained on vasopressin for five days before the infusion was discontinued after clinical improvement. Within 12 hours of vasopressin discontinuation, the patient developed polyuria (> 3 L/day urine output) with volumes as high as 1 L per hour. His serum sodium levels increased more than 10 mmol/L from 137 to 149 mmol/L. This case is unique from prior reports, as our patient was without any neurological or neurosurgical comorbidities that would predispose him to an organic central cause of DI. Furthermore, the patient's large-volume diuresis and serum abnormalities spontaneously self-improved within 24 hours without significant medical intervention. In conclusion, this case adds to a growing number of reports of transient DI following vasopressin withdrawal, demonstrating the need to formally recognize this occurrence as a potential consequence of vasopressin use in intensive care settings.

Development of a nomogram for predicting in-hospital mortality in patients with liver cirrhosis and sepsis

In this study, we aimed to investigate the risk factors associated with in-hospital mortality in patients with cirrhosis and sepsis, establish and validate the nomogram. This retrospective study included patients diagnosed with liver cirrhosis and sepsis in the Medical Information Mart for Intensive Care IV (MIMIC-IV). Models were compared by the area under the curve (AUC), integrated discriminant improvement (IDI), net reclassification index (NRI) and decision curve analysis (DCA). A total of 1,696 patients with cirrhosis and sepsis were included in the final cohort. Our final model included the following 9 variables: age, heartrate, total bilirubin (TBIL), glucose, sodium, anion gap (AG), fungal infections, mechanical ventilation, and vasopressin. The nomogram were constructed based on these variables. The AUC values of the nomograms were 0.805 (95% CI 0.776-0.833), which provided significantly higher discrimination compared to that of SOFA score [0.684 (95% CI 0.647-0.720)], MELD-Na [0.672 (95% CI 0.636-0.709)] and ABIC [0.674(95% CI 0.638-0.710)]. We established the first nomogram for predicting in-hospital mortality in patients with liver cirrhosis and sepsis based on these factors. This nomogram can performs well and facilitates clinicians to identify people at high risk of in-hospital mortality.

Effect of methylene blue on outcomes in patients with distributive shock: a meta-analysis of randomised controlled trials

OBJECTIVE

This meta-analysis aimed to demonstrate the effect of methylene blue (MB) in patients with distributive shock.

DESIGN

Meta-analysis.

METHODS

According to the Prospective International Register of Systematic Reviews (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, we searched the relevant randomised controlled trials (RCTs) via PubMed, Embase and Cochrane Library from the date of database inception to 19 April 2023. The primary outcome was mortality during follow-up, and secondary outcomes included mean arterial pressure (mm Hg), mechanical ventilation time (hours), intensive care unit (ICU) length of stay (LOS) (days), hospital LOS (days) and heart rate (times/min).

RESULTS

This study included six RCTs with 265 participants. The study showed no significant difference in mortality between the MB and placebo groups (ORs: 0.59; 95% CI 0.32 to -1.06). However, MB reduced the duration of mechanical ventilation (mean difference (MD): -0.68; 95% CI -1.23 to -0.14), ICU LOS (MD: -1.54; 95% CI -2.61 to -0.48) and hospital LOS (MD: -1.97; 95% CI -3.92 to -0.11).

CONCLUSIONS

The use of MB may not reduce mortality in patients with distributive shock, but may shorten the duration of mechanical ventilation, ICU LOS and hospital LOS. More clinical studies are needed to confirm these findings in the future.

TRIAL REGISTRATION NUMBER

CRD42023415938.

Factor analysis based on SHapley Additive exPlanations for sepsis-associated encephalopathy in ICU mortality prediction using XGBoost - a retrospective study based on two large database

Objective

Sepsis-associated encephalopathy (SAE) is strongly linked to a high mortality risk, and frequently occurs in conjunction with the acute and late phases of sepsis. The objective of this study was to construct and verify a predictive model for mortality in ICU-dwelling patients with SAE.

Methods

The study selected 7,576 patients with SAE from the MIMIC-IV database according to the inclusion criteria and randomly divided them into training (n = 5,303, 70%) and internal validation (n = 2,273, 30%) sets. According to the same criteria, 1,573 patients from the eICU-CRD database were included as an external test set. Independent risk factors for ICU mortality were identified using Extreme Gradient Boosting (XGBoost) software, and prediction models were constructed and verified using the validation set. The receiver operating characteristic (ROC) and the area under the ROC curve (AUC) were used to evaluate the discrimination ability of the model. The SHapley Additive exPlanations (SHAP) approach was applied to determine the Shapley values for specific patients, account for the effects of factors attributed to the model, and examine how specific traits affect the output of the model.

Results

The survival rate of patients with SAE in the MIMIC-IV database was 88.6% and that of 1,573 patients in the eICU-CRD database was 89.1%. The ROC of the XGBoost model indicated good discrimination. The AUCs for the training, test, and validation sets were 0.908, 0.898, and 0.778, respectively. The impact of each parameter on the XGBoost model was depicted using a SHAP plot, covering both positive (acute physiology score III, vasopressin, age, red blood cell distribution width, partial thromboplastin time, and norepinephrine) and negative (Glasgow Coma Scale) ones.

Conclusion

A prediction model developed using XGBoost can accurately predict the ICU mortality of patients with SAE. The SHAP approach can enhance the interpretability of the machine-learning model and support clinical decision-making.

Efficacy, Safety and Outcomes of the Laparoscopic Management of Cesarean Scar Ectopic Pregnancy as a Single Therapeutic Approach: A Case Series

A standardized consensus for the management of cesarean scar pregnancy (CSP) is lacking. The study objective is to evaluate the efficacy, safety and outcomes of the laparoscopic management of CSP as a single therapeutic surgical approach without being preceded by vascular pretreatment or vasoconstrictors injection. This is a retrospective bi-centric study, a case series. Eight patients with a future desire to conceive underwent the laparoscopic treatment of unruptured CSPs. Surgery consisted of "en bloc" excision of the deficient uterine scar with the adherent tissue of conception, followed by immediate uterine repair. The data collected for each patient was age, gestity, parity, number of previous c-sections, pre-pregnancy isthmocele-related symptoms, gestational age, fetal cardiac activity, initial β-human chorionic gonadotropin levels, intra-operative blood loss, blood transfusion, operative time and the postoperative complications, evaluated according to Clavien-Dindo classification. The CSP was successfully removed in all patients by laparoscopy. The surgical outcomes were favorable. All patients with histories of isthmocele-related symptoms reported postoperative resolution of symptoms. The median residual myometrium thickness increased significantly from 1.2 mm pre-operatively to 8 mm 3 to 6 months after surgery. The laparoscopic management seems to be an appropriate treatment of CSP when performed by skilled laparoscopic surgeons. It can be safely proposed as a single surgical therapeutic approach. Larger series and further prospective studies are needed to confirm this observation and to affirm the long-term gynecological and obstetrical outcomes of this management.

Effect of intravenous low-dose norepinephrine on blood loss in non-tourniquet total knee arthroplasty under general anesthesia: a randomized, double-blind, controlled, single-center trial

OBJECTIVE

This prospective trial aimed to evaluate the effects of low-dose intravenous norepinephrine (NE) on intraoperative blood loss and bleeding from osteotomy sites during non-tourniquet total knee arthroplasty (TKA) under general anesthesia.

METHODS

A total of 120 patients who underwent TKA between December 2020 and May 2022 were enrolled and randomly assigned to the intravenous low-dose NE Group (NE Group) or the control group (C Group). During surgery, NE Group received 0.05-0.1 μg/(kg min) of NE intravenously to raise and maintain the patient's mean arterial pressure (MAP). C Group received the same dose of saline as placebo. Intraoperative blood loss, bleeding score at osteotomy sites, Δlactate levels (Lac), postoperative complications, and transfusion rate during hospitalization were compared between groups.

RESULTS

Intraoperative and osteotomy blood loss was significantly lower in the NE Group than in the C Group (P < 0.001). No significant difference was observed in ΔLac between groups (P > 0.05). There was no significant difference in complications between the groups 3 days after surgery (P > 0.05). In addition, there was no significant difference in blood transfusion rates between the two groups during hospitalization (P > 0.05).

CONCLUSION

In non-tourniquet TKA under general anesthesia, low-dose intravenous NE safely and effectively reduced intraoperative blood loss and provided a satisfactory osteotomy site while maintaining a higher MAP.

Analysis of the Association Between the Number of Intensivists and the Use of Cardiovascular Agonists: An Ecological Study Using Data From National Databases of Japan

Background Previous studies have demonstrated a correlation between management by intensivists and a decrease in hospital stay and mortality, yet the underlying reason remains unknown. Using open data from the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) and other databses, the present study aimed to explore the relationship between inotrope and vasoconstrictor use and the number of intensivists. Materials and methods Cardiovascular agonists listed in the 2020 NDB for which the total dose was known were included for analysis. Trends in cardiovascular agonist use over six years were then graphically assessed, and a linear regression model with the use of each target drug per prefecture as the objective variable in the 2020 data was created to analyze the impact of intensivists on drug use. Results A total of 61 drugs were classified into eight groups based on their composition, and drug use in each of the 47 prefectures was tabulated. Both the rate of use and cost showed a yearly decrease for dopamine but a yearly increase for norepinephrine. Multivariable analysis indicated that the number of intensivists was only significant for dopamine, which had a coefficient of -310 (95% CI: -548 to -72, p = 0.01) but that no such trend was evident for the other drugs. Conclusions The results demonstrated that an increasing number of intensivists in each prefecture correlated with decreasing use of dopamine, possibly explaining the improved outcomes observed in closed ICUs led by intensivists. Further research is warranted to establish causality.

Exploring disease axes as an alternative to distinct clusters for characterizing sepsis heterogeneity

PURPOSE

Various studies have analyzed sepsis subtypes, yet the reproducibility of such results remains unclear. This study aimed to determine the reproducibility of sepsis subtypes across multiple cohorts.

METHODS

The study examined 63,547 sepsis patients from six distinct cohorts who had similar sepsis-related characteristics (vital signs, lactate, sequential organ failure assessment score, bilirubin, serum, urine output, and Glasgow coma scale). Identical cluster analysis techniques were used, employing 27 clustering schemes, and normalized mutual information (NMI), a metric ranging from 0 to 1 with higher values indicating better concordance, was employed to quantify the clustering solutions' reproducibility. Principal component analysis (PCA) was utilized to obtain the disease axis, and its uniformity across cohorts was evaluated through patterns of feature loading and correlation.

RESULTS

The reproducibility of sepsis clustering subtypes across the various studies was modest (median NMI ranging from 0.08 to 0.54). The top-down transfer learning method (model trained on cohorts with greater severity was transferred to cohorts with lower severity score) had a higher NMI value than the bottom-up approach (median [Q1, Q3]: 0.64 [0.49, 0.78] vs. 0.23 [0.2, 0.31], p < 0.001). The reproducibility was greater when the transfer solution was performed within United States (US) cohorts. The PCA analysis revealed that the correlation pattern between variables was consistent across all cohorts, and the first two disease axes were the "shock axis" and "systemic inflammatory response syndrome (SIRS) axis."

CONCLUSIONS

Cluster analysis of sepsis patients across various cohorts showed modest reproducibility. Sepsis heterogeneity is better characterized through continuous disease axes that coexist to varying degrees within the same individual instead of mutually exclusive subtypes.

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.

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.

Low and Highly Variable Exposure to Prophylactic LMWH Nadroparin in Critically Ill Patients: Back to the Drawing Board for Prophylactic Dosing?

BACKGROUND AND OBJECTIVE

Low-molecular-weight heparins are routinely administered to patients in the intensive care unit to prevent venous thromboembolisms. There is considerable evidence that low-molecular-weight heparin doses should be personalised based on anti-Xa levels, but pharmacokinetic data in intensive care unit patients are lacking. This study aimed to characterise the pharmacokinetics and associated variability of the low-molecular-weight heparin nadroparin in critically ill patients.

METHODS

Critically ill adult patients who were admitted to the intensive care unit and received nadroparin for prophylaxis of venous thromboembolism were included in a study. Population pharmacokinetic analysis was performed by means of parametric non-linear mixed-effects modelling (NONMEM).

RESULTS

A total of 30 patients were enrolled with 12 patients undergoing continuous veno-venous hemodialysis and 18 patients not undergoing continuous veno-venous hemodialysis. Very high variability in pharmacokinetics was observed with an inter-individual variability in the volume of distribution of 63.7% (95% confidence interval 46.5-90.6), clearance of 166% (95% confidence interval 84.7-280) and relative bioavailability of 40.2% (95% confidence interval 29.5-52.6). We found that standard doses of 2850 IE and 5700 IE of nadroparin resulted in sub-prophylactic exposure in critically ill patients.

CONCLUSIONS

Low exposure and highly variable pharmacokinetics of nadroparin were observed in intensive care unit patients treated with a prophylactic dose. It can be debated whether nadroparin is currently dosed optimally in intensive care unit patients and our findings encourage the investigation of higher and tailored dosing of nadroparin in the critically ill.

Evaluation of the Addition of Angiotensin II in Patients With Shock After Cardiac Surgery at a Veterans Affairs Medical Center

BACKGROUND

Vasoplegic shock occurs in up to 37% of cardiac surgery patients. We investigated the use of angiotensin II for treating vasoplegic shock in these patients.

OBJECTIVES

We assessed clinical outcomes and mortality in patients undergoing cardiac surgery at our center between March 1, 2018 and October 31, 2020 who developed vasoplegic shock, comparing those who received angiotensin II with those who did not.

METHODS

This was a retrospective chart review. Response to angiotensin II was defined as increase in or maintenance of mean arterial pressure (MAP) and decrease in background vasopressor dosage.

RESULTS

Angiotensin II was administered to 7 patients (postoperatively in 4 patients [57.1%]) with vasoplegic shock and baseline norepinephrine equivalent (NEE) of 0.49 ± 0.08 μg/kg/min; 12 patients with vasoplegic shock did not receive angiotensin II. Within 3 hours of angiotensin II administration, NEE decreased by 38.0 ± 33.1%. Angiotensin patients were more likely to newly require renal replacement therapy (66.7% vs 9.1%, P = 0.03) and had a longer, although not statistically significant, postoperative stay (23.1 vs 14.0 days, P = 0.16). Despite higher NEE requirements at baseline (0.49 vs 0.30, P = 0.03) and over the next 48 hours in the angiotensin group, no between-group differences in 7-day mortality (14.3% vs 0.0%, P = 0.37) or 30-day mortality (28.6% vs 8.3%, P = 0.52) were noted.

CONCLUSION AND RELEVANCE

In patients who developed vasoplegic shock after cardiac surgery, angiotensin II administration allowed immediate dosage reductions of other vasopressors while maintaining MAP. Despite its small sample size, this study adds to the paucity of data in these patients and highlights future research needs.

Use of vasoactive agents in non-cardiac surgery: Protocol for a scoping review

BACKGROUND

An increasing number of patients undergo surgical procedures worldwide each year, and despite advances in quality and care, morbidity and mortality rates remain high. Perioperative hypotension is a well-described condition, and is associated with adverse outcomes. Both fluids and vasoactive agents are commonly used to treat hypotension, however, whether one vasoactive agent is preferable over another has yet to be explored.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) statement, we plan to conduct a scoping review of studies assessing the use of vasoactive agents in patients undergoing non-cardiac surgery. We will provide an overview of indications, agents used and outcomes assessed. We will assess and report the certainty of evidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

RESULTS

We will provide descriptive analyses of the included studies accompanied by tabulated results.

CONCLUSION

The outlined scoping review will provide a summary of the body of evidence on the use of vasoactive agents in the non-cardiac surgical population.

Acute liver injury in COVID-19 patients hospitalized in the intensive care unit: Narrative review

In recent years, humanity has been confronted with a global pandemic due to coronavirus disease 2019 (COVID-19), which has caused an unprecedented health and economic crisis worldwide. Apart from the respiratory symptoms, which are considered the principal manifestations of COVID-19, it has been recognized that COVID-19 constitutes a systemic inflammatory process affecting multiple organ systems. Across the spectrum of organ involvement in COVID-19, acute liver injury (ALI) has been gradually gaining increasing attention by the international scientific community. COVID-19 associated liver impairment can affect a considerable proportion of COVID-19 patients and seems to correlate with the severity of the disease course. Indeed, COVID-19 patients hospitalized in the intensive care unit (ICU) run a greater risk of developing ALI due to the severity of their clinical condition and in the context of multi-organ failure. The putative pathophysiological mechanisms of COVID-19 induced ALI in ICU patients remain poorly understood and appear to be multifactorial in nature. Several theories have been proposed to explain the occurrence of ALI in the ICU setting, such as hypoperfusion and ischemia due to hemodynamic instability, passive liver congestion as a result of congestive heart failure, ischemia-reperfusion injury, hypoxia due to respiratory failure, mechanical ventilation itself, sepsis and septic shock, cytokine storm, endotheliitis with concomitant coagulopathy, drug-induced liver injury, parenteral nutrition and direct cytopathic viral effect. It should be noted that no specific therapy for COVID-19 induced ALI exists. Therefore, the therapeutic approach lies in preventive measures and is exclusively supportive once ALI ensues. The aim of the current review is to scrutinize the existing evidence on COVID-19 associated ALI in ICU patients, explore its clinical implications, shed light on the underlying pathophysiological mechanisms and propose potential therapeutic approaches. Ongoing research on the particular scientific field will further elucidate the pathophysiology behind ALI and address unresolved issues, in the hope of mitigating the tremendous health consequences imposed by COVID-19 on ICU patients.

The Heart as a Target of Vasopressin and Other Cardiovascular Peptides in Health and Cardiovascular Diseases

The automatism of cardiac pacemaker cells, which is tuned, is regulated by the autonomic nervous system (ANS) and multiple endocrine and paracrine factors, including cardiovascular peptides. The cardiovascular peptides (CPs) form a group of essential paracrine factors affecting the function of the heart and vessels. They may also be produced in other organs and penetrate to the heart via systemic circulation. The present review draws attention to the role of vasopressin (AVP) and some other cardiovascular peptides (angiotensins, oxytocin, cytokines) in the regulation of the cardiovascular system in health and cardiovascular diseases, especially in post-infarct heart failure, hypertension and cerebrovascular strokes. Vasopressin is synthesized mostly by the neuroendocrine cells of the hypothalamus. There is also evidence that it may be produced in the heart and lungs. The secretion of AVP and other CPs is markedly influenced by changes in blood volume and pressure, as well as by other disturbances, frequently occurring in cardiovascular diseases (hypoxia, pain, stress, inflammation). Myocardial infarction, hypertension and cardiovascular shock are associated with an increased secretion of AVP and altered responsiveness of the cardiovascular system to its action. The majority of experimental studies show that the administration of vasopressin during ventricular fibrillation and cardiac arrest improves resuscitation, however, the clinical studies do not present consisting results. Vasopressin cooperates with the autonomic nervous system (ANS), angiotensins, oxytocin and cytokines in the regulation of the cardiovascular system and its interaction with these regulators is altered during heart failure and hypertension. It is likely that the differences in interactions of AVP with ANS and other CPs have a significant impact on the responsiveness of the cardiovascular system to vasopressin in specific cardiovascular disorders.

The Potential Synergistic Risk of Albuterol and Vasoactives in Acute Lung Injury Trials

Background:

Critically ill patients are often prescribed both inhaled beta-agonists and intravenous vasoactive; however, the interaction of the additive beta-agonist effects of these 2 agents remains largely uncharacterized.

Objective:

The purpose of this study was to evaluate how concomitant use of albuterol and vasoactive or inotropes affected ventilator-free days (VFDs) by re-analyzing the data from the Albuterol to Treat Acute Lung Injury (ALTA) trial.

Methods:

In this study, subjects were grouped to albuterol-vasoactive (n = 84) versus (vs) placebo-vasoactive (n = 62). Ventilator-free days, intensive care unit (ICU)-free days, organ failure-free days, cardiovascular adverse events, and 90-day mortality were compared. The primary outcome was VFDs.

Results:

Patients in the albuterol-vasoactive group had significantly fewer VFDs than patients in the placebo-vasoactive group (11 vs 19, P = 0.05). Patients in the albuterol-vasoactive group also had significantly fewer ICU-free days (9.5 vs 18.5, P = .006). The 90-day mortality was similar between groups (36.9% vs 27.4%, P = .20). Similarly, no significant difference in cardiac adverse events between the groups (14.3% vs 11.3%, P = 0.59).

Conclusion and Relevance:

This study has shown fewer VFDs for patients who received both vasoactive and albuterol. There were also fewer ICU-free days when compared to those on vasoactive only. Given the common use of both agents, a prospective evaluation of the additive adverse effects of beta-agonism is warranted.

Characterization of Pediatric Patients with Rheumatological Diseases Admitted to a Single Tertiary Health Hospital's Pediatric Intensive Care Unit in Latin America

Most autoimmune diseases (AIDs) during childhood debut with more severe and aggressive forms, with life-threatening conditions that increase the need for intensive care therapy. This study describes the clinical, laboratory, and health outcome features of pediatric patients with AIDs admitted to the pediatric intensive care unit (PICU). This is a retrospective cross-sectional study that included the clinical records of all pediatric patients with AIDs admitted to the PICU between 2011 and 2020 in Cali, Colombia. In total, 225 PICU admissions from 136 patients were evaluated. Median age was 13 (11–15) years, and the median disease duration was 15 (5–38.5) months. Systemic lupus erythematosus was the most prevalent disease (91, 66.9%), followed by vasculitis (27, 19.8%). The leading cause of PICU admission was AID activity (95, 44.3%). C-reactive-protein levels were associated with infections (p <0.0394). Mortality occurred in 12 (8.8%) patients secondary to AID activity, primarily, diffuse alveolar hemorrhage (6, 50%). A longer disease duration was associated with mortality (p <0.00398). AID activity was the leading cause of PICU admission and mortality. Pulse steroid therapy, mechanical ventilation, and inotropic and vasopressor support were associated with nonsurvival.

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.

Alternatives to norepinephrine in septic shock: Which agents and when?

Vasopressors are the cornerstone of hemodynamic management in patients with septic shock. Norepinephrine is currently recommended as the first-line vasopressor in these patients. In addition to norepinephrine, there are many other potent vasopressors with specific properties and/or advantages that act on vessels through different pathways after activation of specific receptors; these could be of interest in patients with septic shock. Dopamine is no longer recommended in patients with septic shock because its use is associated with a higher rate of cardiac arrhythmias without any benefit in terms of mortality or organ dysfunction. Epinephrine is currently considered as a second-line vasopressor therapy, because of the higher rate of associated metabolic and cardiac adverse effects compared with norepinephrine; however, it may be considered in settings where norepinephrine is unavailable or in patients with refractory septic shock and myocardial dysfunction. Owing to its potential effects on mortality and renal function and its norepinephrine-sparing effect, vasopressin is recommended as second-line vasopressor therapy instead of norepinephrine dose escalation in patients with septic shock and persistent arterial hypotension. However, two synthetic analogs of vasopressin, namely, terlipressin and selepressin, have not yet been employed in the management of patients with septic shock, as their use is associated with a higher rate of digital ischemia. Finally, angiotensin Ⅱ also appears to be a promising vasopressor in patients with septic shock, especially in the most severe cases and/or in patients with acute kidney injury requiring renal replacement therapy. Nevertheless, due to limited evidence and concerns regarding safety (which remains unclear because of potential adverse effects related to its marked vasopressor activity), angiotensin Ⅱ is currently not recommended in patients with septic shock. Further studies are needed to better define the role of these vasopressors in the management of these patients.

Vasopressors and Risk of Acute Mesenteric Ischemia: A Worldwide Pharmacovigilance Analysis and Comprehensive Literature Review

Vasodilatory shock, such as septic shock, requires personalized management which include adequate fluid therapy and vasopressor treatments. While these potent drugs are numerous, they all aim to counterbalance the vasodilatory effects of a systemic inflammatory response syndrome. Their specific receptors include α- and β-adrenergic receptors, arginine-vasopressin receptors, angiotensin II receptors and dopamine receptors. Consequently, these may be associated with severe adverse effects, including acute mesenteric ischemia (AMI). As the risk of AMI depends on drug class, we aimed to review the evidence of plausible associations by performing a worldwide pharmacovigilance analysis based on the World Health Organization database, VigiBase®. Among 24 million reports, 104 AMI events were reported, and disproportionality analyses yielded significant association with all vasopressors, to the exception of selepressin. Furthermore, in a comprehensive literature review, we detailed mechanistic phenomena which may enhance vasopressor selection, in the course of treating vasodilatory shock.

Vasopressin and Its Analogues: From Natural Hormones to Multitasking Peptides

Human neurohormone vasopressin (AVP) is synthesized in overlapping regions in the hypothalamus. It is mainly known for its vasoconstricting abilities, and it is responsible for the regulation of plasma osmolality by maintaining fluid homeostasis. Over years, many attempts have been made to modify this hormone and find AVP analogues with different pharmacological profiles that could overcome its limitations. Non-peptide AVP analogues with low molecular weight presented good affinity to AVP receptors. Natural peptide counterparts, found in animals, are successfully applied as therapeutics; for instance, lypressin used in treatment of diabetes insipidus. Synthetic peptide analogues compensate for the shortcomings of AVP. Desmopressin is more resistant to proteolysis and presents mainly antidiuretic effects, while terlipressin is a long-acting AVP analogue and a drug recommended in the treatment of varicose bleeding in patients with liver cirrhosis. Recently published results on diverse applications of AVP analogues in medicinal practice, including potential lypressin, terlipressin and ornipressin in the treatment of SARS-CoV-2, are discussed.

Comparison of push-dose phenylephrine and epinephrine in the emergency department

BACKGROUND

There is limited evidence to support the efficacy and safety of push-dose vasopressor (PDP) use outside of the operating room (OR). Specifically, there are few head-to-head comparisons of different PDP in these settings. The purpose of this study was to compare the efficacy and safety of push-dose phenylephrine (PDP-PE) and epinephrine (PDP-E) in the Emergency Department (ED).

METHODS

This retrospective, single-center study evaluated adults given PDP-PE or PDP-E in the ED from May 2017 to November 2020. The primary outcome was a change in heart rate (HR). Secondary outcomes included changes in blood pressure, adverse effects, dosing errors, fluid and vasopressor requirements, ICU and hospital lengths of stay (LOS), and in-hospital mortality.

RESULTS

Ninety-six patients were included in the PDP-PE group and 39 patients in the PDP-E group. Median changes in HR were 0 [-7, 6] and - 2 [-15, 5] beats per minute (BPM) for PDP-PE and PDP-E, respectively (p = 0.138). PDP-E patients had a greater median increase in systolic blood pressure (SBP) (33 [24, 53] vs. 26 [8, 51] mmHg; p = 0.049). Dosing errors occurred more frequently in patients that received PDP-E (5/39 [12.8%] vs. 2/96 [2.1%]; p = 0.021). PDP-E patients more frequently received continuous epinephrine infusions before and after receiving PDP-E. There were no differences in adverse effects, fluid requirements, LOS, or mortality.

CONCLUSION

PDP-E provided a greater increase in SBP compared to PDP-PE. However, dosing errors occurred more frequently in those receiving PDP-E. Larger head-to-head studies are necessary to further evaluate the efficacy and safety of PDP-E and PDP-PE.

Vasopressor-Sparing Strategies in Patients with Shock: A Scoping-Review and an Evidence-Based Strategy Proposition

Despite the abundant literature on vasopressor therapy, few studies have focused on vasopressor-sparing strategies in patients with shock. We performed a scoping-review of the published studies evaluating vasopressor-sparing strategies by analyzing the results from randomized controlled trials conducted in patients with shock, with a focus on vasopressor doses and/or duration reduction. We analyzed 143 studies, mainly performed in septic shock. Our analysis demonstrated that several pharmacological and non-pharmacological strategies are associated with a decrease in the duration of vasopressor therapy. These strategies are as follows: implementing a weaning strategy, vasopressin use, systemic glucocorticoid administration, beta-blockers, and normothermia. On the contrary, early goal directed therapies, including fluid therapy, oral vasopressors, vitamin C, and renal replacement therapy, are not associated with an increase in vasopressor-free days. Based on these results, we proposed an evidence-based vasopressor management strategy.