Association of systolic, diastolic, mean, and pulse pressure with morbidity and mortality in septic ICU patients: a nationwide observational study

Intraoperative hypotension during liver transplantation and postoperative outcomes: Retrospective cohort study

STUDY OBJECTIVES

Evaluation of the association between intraoperative hypotension (IOH) and important postoperative outcomes after liver transplant such as incidence and severity of acute kidney injury (AKI), MACE and early allograft dysfunction (EAD).

DESIGN

Retrospective, single institution study.

SETTINGS

Operating room.

PATIENTS

1576 patients who underwent liver transplant in our institution between January 2005 and February 2022.

MEASUREMENTS

IOH was measured as the time, area under the threshold (AUT), or time-weighted average (TWA) of mean arterial pressure (MAP) less than certain thresholds (55,60 and 65 mmHg). Associations between IOH exposures and AKI severity were assessed via proportional odds models. The odds ratio from the proportional odds model estimated the relative odds of having higher stage of AKI for higher exposure to IOH. Associations between exposures and MACE and EAD were assessed through logistic regression models. Potential confounding variables including patient baseline and surgical characteristics were adjusted for all models.

MAIN RESULTS

The primary analysis included 1576 surgeries that met the inclusion and exclusion criteria. Of those, 1160 patients (74%) experienced AKI after liver transplant surgery, with 780 (49%), 248(16%), and 132 (8.4%) experiencing mild, moderate, and severe injury, respectively. No significant association between hypotension exposure and postoperative AKI (yes or no) nor severity of AKI was observed. The odds ratios (95% CI) of having more severe AKI were 1.02 (0.997, 1.04) for a 50-mmHg·min increase in AUT of MAP <55 mmHg (P = 0.092); 1.03 (0.98, 1.07) for a 15-min increase in time spent under MAP <55 mmHg (P = 0.27); and 1.24 (0.98, 1.57) for a 1 mmHg increase in TWA of MAP <55 mmHg (P = 0.068). The associations between IOH and the incidence of MACE or EAD were not significant.

CONCLUSION

Our results did not show the association between IOH and investigated outcomes.

A comparison of invasive arterial blood pressure measurement with oscillometric non-invasive blood pressure measurement in patients with sepsis

PURPOSE

This study aimed to compare non-invasive oscillometric blood pressure (NIBP) measurement with invasive arterial blood pressure (IBP) measurement in patients with sepsis.

METHODS

We conducted a retrospective study to evaluate the agreement between IBP and NIBP using the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Paired blood pressure measurements of mean arterial pressure (MAP), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were compared using Bland-Altman analysis and paired Student's t test. We also focus on the effect of norepinephrine (NE) on the agreement between the two methods and the association between blood pressure and mortality during intensive care unit (ICU) stay.

RESULTS

A total of 96,673 paired blood pressure measurements from 6060 unique patients were analyzed in the study. In Bland-Altman analysis, the bias (± SD, 95% limits of agreement) was 6.21 mmHg (± 12.05 mmHg, - 17.41 to 29.83 mmHg) for MAP, 0.39 mmHg (± 19.25 mmHg, - 37.34 to 38.12 mmHg) for SBP, and 0.80 mmHg (± 12.92 mmHg, - 24.52 to 26.12 mmHg) for DBP between the two techniques. Similarly, large limits of agreement were shown in different groups of NE doses. NE doses significantly affected the agreement between IBP and NIBP. SBP between the two methods gave an inconsistent assessment of patients' risk of ICU mortality.

CONCLUSION

IBP and NIBP were not interchangeable in septic patients. Clinicians should be aware that non-invasive MAP was clinically and significantly underestimated invasive MAP.

Blood neutrophil to lymphocyte ratio is associated with 90-day mortality and 60-day readmission in Gram negative bacteremia: a multi-center cohort study

INTRODUCTION

The Neutrophil-Lymphocyte Ratio (NLR) in blood has demonstrated its capability to predict bacteremia in emergency departments, and its association with mortality has been established in patients with sepsis in intensive care units. However, its potential concerning mortality and readmission in patients with Gram-negative bacteremia (GNB) is unexplored.

METHODS

This retrospective cohort study included patients with GNB between 2018 and 2022 from six hospitals in the Capital Region of Denmark. Patients who were immunosuppressed or had missing NLR values on the day of blood culture were excluded. Logistic regression models were used to analyze the association between NLR levels and 90-day all-cause mortality, while the logit link interpretation of the cumulative incidence function was used to assess the association between NLR levels and 60-day readmission. Associations were quantified as odds ratios (OR) with corresponding 95% confidence intervals (CI).

RESULTS

The study included 1763 patients with a median age was 76.8 years and 51.3% were female. The median NLR was 17.3 and 15.8% of patients had a quick sequential organ failure assessment score of two or three. Urinary tract infection (UTI) was the most frequent focus and Escherichia coli the most frequent pathogen. Statistically significant differences in median NLR were found by age group and pathogen, and for patients with or without hypertension, liver disease, chronic obstructive pulmonary disease, dementia, and alcohol abuse. 378 patients (21.4%) died before 90 days. 526 (29.8%) patients were readmitted to the hospital within 60 days. For each doubling of the NLR, the OR for all-cause 90-day mortality was 1.15 (95% CI, 1.04-1.27) and 1.12 (95% CI, 1.02-1.24) for 60-day readmission. Analysis of subgroups did not show statistically significant differences between groups in relation to the association between NLR and mortality. The discriminatory ability of NLR for mortality was limited and comparable to blood neutrophil or lymphocyte count, producing receiver operating characteristic curves with an area under the curve of 0.59 (95% CI, 0.56-0.63), 0.60 (95% CI, 0.56-0.65) and 0.53 (95% CI, 0.49-0.56), respectively.

CONCLUSION

Blood neutrophil-lymphocyte ratio was associated with 90-day all-cause mortality and 60-day readmission in patients with GNB. However, the ratio has limited ability in predicting mortality or readmission.

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.

The roles of tissue-resident macrophages in sepsis-associated organ dysfunction

Sepsis, a syndrome caused by a dysregulated host response to infection and characterized by life-threatening organ dysfunction, particularly septic shock and sepsis-associated organ dysfunction (SAOD), is a medical emergency associated with high morbidity, high mortality, and long-term sequelae. Tissue-resident macrophages (TRMs) are a subpopulation of macrophages derived primarily from yolk sac progenitors and fetal liver during embryogenesis, located primarily in non-lymphoid tissues in adulthood, capable of local self-renewal independent of hematopoiesis, and developmentally and functionally restricted to the non-lymphoid organs in which they reside. TRMs are the first line of defense against life-threatening conditions such as sepsis, tumor growth, traumatic-associated organ injury, and surgical-associated injury. In the context of sepsis, TRMs can be considered as angels or demons involved in organ injury. Our proposal is that sepsis, septic shock, and SAOD can be attenuated by modulating TRMs in different organs. This review summarizes the pathophysiological mechanisms of TRMs in different organs or tissues involved in the development and progression of sepsis.

Blood Pressure Goals in Critically Ill Patients

Blood pressure goals in the intensive care unit (ICU) have been extensively investigated in large datasets and have been associated with various harm thresholds at or greater than a mean pressure of 65 mm Hg. While it is difficult to perform interventional randomized trials of blood pressure in the ICU, important evidence does not support defense of a higher pressure, except in retrospective database analyses. Perfusion pressure may be a more important target than mean pressure, even more so in the vulnerable patient population. In the cardiac ICU, blood pressure targets are tailored to specific cardiac pathophysiology and patient characteristics. Generally, the goal is to maintain adequate blood pressure within a certain range to support cardiac function and to ensure end organ perfusion. Individualized targets demand the use of both invasive and noninvasive monitoring modalities and frequent titration of medications and/or mechanical circulatory support where necessary. In this review, we aim to identify appropriate blood pressure targets in the ICU, recognizing special patient populations and outlining the risk factors and predictors of end organ failure.