Invasive arterial pressure monitoring: much more than mean arterial pressure!

Novel pulse pressure pattern monitoring in critical care of elderly sepsis patients

OBJECTIVE

Our research aimed to explore the application of pulse pressure (PP) at the bedside of elderly intensive care unit (ICU) patients with sepsis through a large-scale retrospective cohort study.

METHODS

We obtained data from four heterogeneous datasets, which included information on elderly sepsis patients (≥ 65 years). The data were divided into the inference and validation datasets. Thereby enhancing the generalizability of the study. The primary outcome was mortality at 28 days, and piecewise exponential additive mixed model (PAMM) were employed to estimate the strength of the associations over time.

RESULTS

We included 12,525 elderly patients with sepsis in the initial inference dataset. Based on the PAMM's inference results, we identified a specific low PP phenotype from the time-dependent endpoint dataset. The phenotype indicates an imbalance between the patient's cardiac pumping ability and circulatory resistance, contributing to an increased 28-day mortality (hazard ratio, 2.36; 95% CI, 2.12-2.63). The consistency of these results was validated using data from various sources.

CONCLUSION

Low PP phenotype (PP < 45 mmHg 72 h after intensive care unit admission and lasting for > 3h) may provide an early dynamic warning of the therapeutic effects of resuscitation interventions in long-hospitalized elderly patients with sepsis.

IMPLICATIONS FOR CLINICAL PRACTICE

The results demonstrate acceptable consistency across heterogeneous datasets and hold promise for further development and integration into bedside monitoring systems for elderly sepsis patients.

U shaped relationship between mean arterial pressure and 28 day mortality in ICU patients with acute myocardial infarction

The current study aims to investigate the correlation between mean arterial pressure (MAP) and the risk of 28-day mortality in patients with acute myocardial infarction. This is a retrospective cohort study utilizing data from the eICU database, focusing on patients with acute myocardial infarction. We employed a multivariable logistic regression model to estimate the relationship between MAP and the 28-day mortality rate. Among 8161 patients with a median age of 67 years, 602 (7.38%) died within 28 days of ICU admission. Smooth curve fitting and generalized additive model analysis identified a threshold effect at MAP of 84 mmHg. We found that when MAP is less than 84 mmHg, a 10 mmHg increase in MAP reduces the mortality rate by approximately 40.13%. Specifically, for every 1 mmHg increase in MAP within this range, the mortality rate decreases significantly by 5% (OR = 0.95, 95% CI (0.93, 0.96), p < 0.0001). Conversely, above the threshold (MAP ≥ 84 mmHg), for every 10 mmHg increase, the mortality rate increases by 34.39% (OR = 1.3439, calculated based on the fact that a 1 mmHg MAP increase causes a 3% mortality rise (OR = 1.03, 95% CI (1.02, 1.03), p < 0.0001), showing a U-shaped association between MAP and 28-day mortality. We found that the baseline MAP at ICU admission, when in the range of 57-110 mmHg, was associated with the lowest 28-day all-cause mortality risk. The relationship between MAP and the risk of 28-day mortality forms a U-shaped curve, indicating that both higher and lower MAP levels are associated with an increased risk of 28-day mortality in ICU-admitted patients.

Invasive Arterial BP Measurements in the Emergency Department-When, if Ever, is it Indicated?

PURPOSE OF REVIEW

Extremes of blood pressure (BP) are common among patients that visit emergency departments. In this review article, we discuss the specific indications for invasive blood pressure monitoring in the ED, particularly in the context of undifferentiated shock and hypertensive emergencies.

RECENT FINDINGS

In most cases, non-invasive techniques suffice for blood pressure monitoring, however, in certain patient presentations intermittent automated oscillometry bears significant drawbacks. The most evident drawback is the extended intervals between measurements. Invasive BP (IBP) monitoring offers a pivotal tool for patients with critical illness who require accurate, timely, blood pressure monitoring and indirectly monitors for complications involving vital organ systems. In the management of patients with critical illness or at risk for end organ injury, invasive methods that directly measure BP via arterial cannulation continues to be an established standard. Overall, evaluating patients on an individual basis, with the understanding that patients who present with extreme blood pressure values need closer monitoring, should prompt consideration of invasive methods of blood pressure monitoring.

Blood Pressure Management for Hypotensive Patients in Intensive Care and Perioperative Cardiovascular Settings

Blood pressure is a critical physiological parameter, particularly in the context of cardiac intensive care and perioperative settings. As a primary indicator of organ perfusion, the maintenance of adequate blood pressure is imperative for the assurance of sufficient tissue oxygen delivery. Among critically ill and major surgery patients, the continuous monitoring of blood pressure is performed as a standard practice for patients. Nonetheless, uncertainties remain regarding blood pressure goals, and there is no consensus regarding blood pressure targets. This review describes the determinants of blood pressure, examine the influence of blood pressure on organ perfusion, and synthesize the current clinical evidence from various intensive care and perioperative settings to provide a concise guidance for daily clinical practice.

Resuscitating the macro- vs. microcirculation in septic shock

PURPOSE OF REVIEW

This review summarizes current literature about the relationships between macro and microcirculation and their practical clinical implications in children with septic shock.

RECENT FINDINGS

Current evidence from experimental and clinical observational studies in children and adults with septic shock reveals that the response to treatment and resuscitation is widely variable. Furthermore, there is a loss of hemodynamic coherence, as resuscitation-induced improvement in macrocirculation (systemic hemodynamic parameters) does not necessarily result in a parallel improvement in the microcirculation. Therefore, patient-tailored monitoring is essential in order to adjust treatment requirements during resuscitation in septic shock. Optimal monitoring must integrate macrocirculation (heart rate, blood pressure, cardiac output, and ultrasound images), microcirculation (videomicroscopy parameters and capillary refill time) and cellular metabolism (lactic acid, central venous blood oxygen saturation, and difference of central venous to arterial carbon dioxide partial pressure).

SUMMARY

There is a dire need for high-quality studies to assess the relationships between macrocirculation, microcirculation and tissue metabolism in children with septic shock. The development of reliable and readily available microcirculation and tissue perfusion biomarkers (other than lactic acid) is also necessary to improve monitoring and treatment adjustment in such patients.

Improved prediction of sepsis-associated encephalopathy in intensive care unit sepsis patients with an innovative nomogram tool

Background

Sepsis-associated encephalopathy (SAE) occurs as a result of systemic inflammation caused by sepsis. It has been observed that the majority of sepsis patients experience SAE while being treated in the intensive care unit (ICU), and a significant number of survivors continue suffering from cognitive impairment even after recovering from the illness. The objective of this study was to create a predictive nomogram that could be used to identify SAE risk factors in patients with ICU sepsis.

Methods

We conducted a retrospective cohort study using the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. We defined SAE as a Glasgow Coma Scale (GCS) score of 15 or less, or delirium. The patients were randomly divided into training and validation cohorts. We used least absolute shrinkage and selection operator (LASSO) regression modeling to optimize feature selection. Independent risk factors were determined through a multivariable logistic regression analysis, and a prediction model was built. The performance of the nomogram was evaluated using various metrics including the area under the receiver operating characteristic curve (AUC), calibration plots, Hosmer-Lemeshow test, decision curve analysis (DCA), net reclassification improvement (NRI), and integrated discrimination improvement (IDI).

Results

Among the 4,476 sepsis patients screened, 2,781 (62.1%) developed SAE. In-hospital mortality was higher in the SAE group compared to the non-SAE group (9.5% vs. 3.7%, p < 0.001). Several variables were analyzed, including the patient's age, gender, BMI on admission, mean arterial pressure, body temperature, platelet count, sodium level, and use of midazolam. These variables were used to create and validate a nomogram. The nomogram's performance, assessed by AUC, NRI, IDI, and DCA, was found to be superior to the conventional SOFA score combined with delirium. Calibration plots and the Hosmer-Lemeshow test confirmed the accuracy of the nomogram. The enhanced NRI and IDI values demonstrated that our scoring system outperformed traditional diagnostic approaches. Additionally, the DCA curve indicated the practicality of the nomogram in clinical settings.

Conclusion

This study successfully identified autonomous risk factors associated with the emergence of SAE in sepsis patients and utilized them to formulate a predictive model. The outcomes of this investigation have the potential to serve as a valuable clinical resource for the timely detection of SAE in patients.

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

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

Towards the personalization of septic shock resuscitation: the fundamentals of ANDROMEDA-SHOCK-2 trial

Septic shock is a highly lethal and prevalent disease. Progressive circulatory dysfunction leads to tissue hypoperfusion and hypoxia, eventually evolving to multiorgan dysfunction and death. Prompt resuscitation may revert these pathogenic mechanisms, restoring oxygen delivery and organ function. High heterogeneity exists among the determinants of circulatory dysfunction in septic shock, and current algorithms provide a stepwise and standardized approach to conduct resuscitation. This review provides the pathophysiological and clinical rationale behind ANDROMEDA-SHOCK-2, an ongoing multicenter randomized controlled trial that aims to compare a personalized resuscitation strategy based on clinical phenotyping and peripheral perfusion assessment, versus standard of care, in early septic shock resuscitation.

Haemodynamic support for paediatric septic shock: a global perspective

Septic shock is a leading cause of hospitalisation, morbidity, and mortality for children worldwide. In 2020, the paediatric Surviving Sepsis Campaign (SSC) issued evidence-based recommendations for clinicians caring for children with septic shock and sepsis-associated organ dysfunction based on the evidence available at the time. There are now more trials from multiple settings, including low-income and middle-income countries (LMICs), addressing optimal fluid choice and amount, selection and timing of vasoactive infusions, and optimal monitoring and therapeutic endpoints. In response to developments in adult critical care to trial personalised haemodynamic management algorithms, it is timely to critically reassess the current state of applying SSC guidelines in LMIC settings. In this Viewpoint, we briefly outline the challenges to improve sepsis care in LMICs and then discuss three key concepts that are relevant to management of children with septic shock around the world, especially in LMICs. These concepts include uncertainties surrounding the early recognition of paediatric septic shock, choices for initial haemodynamic support, and titration of ongoing resuscitation to therapeutic endpoints. Specifically, given the evolving understanding of clinical phenotypes, we focus on the controversies surrounding the concepts of early fluid resuscitation and vasoactive agent use, including insights gained from experience in LMICs and high-income countries. We outline the key components of sepsis management that are both globally relevant and translatable to low-resource settings, with a view to open the conversation to the large variety of treatment pathways, especially in LMICs. We emphasise the role of simple and easily available monitoring tools to apply the SSC guidelines and to tailor individualised support to the patient's cardiovascular physiology.

Transpulmonary thermodilution

PURPOSE OF REVIEW

The purpose of this article is to systematically review and critically assess the existing data regarding the use of transpulmonary thermodilution (TPTD), by providing a detailed description of technical aspects of TPTD techniques, appraising the use of TPTD-derived parameters in specific clinical settings, and exploring the limits of this technique.

RECENT FINDINGS

The aim of hemodynamic monitoring is to optimize cardiac output (CO) and therefore improve oxygen delivery to the tissues. Hemodynamic monitoring plays a fundamental role in the management of acutely ill patients. TPTD is a reliable, multiparametric, advanced cardiopulmonary monitoring technique providing not only hemodynamic parameters related to cardiac function, but also to the redistribution of the extravascular water in the thorax. The hemodynamic monitors available in the market usually couple the intermittent measurement of the CO by TPTD with the arterial pulse contour analysis, offering automatic calibration of continuous CO and an accurate assessment of cardiac preload and fluid responsiveness.

SUMMARY

The TPTD is an invasive but well tolerated, multiparametric, advanced cardiopulmonary monitoring technique, allowing a comprehensive assessment of cardiopulmonary condition. Beyond the CO estimation, TPTD provides several indices that help answering questions that clinicians ask themselves during hemodynamic management. TPTD-guided algorithm obtained by pulse contour analysis may be useful to optimize fluid resuscitation by titrating fluid therapy according to functional hemodynamic monitoring and to define safety criteria to avoid fluid overload by following the changes in the extravascular lung water (EVLW) and pulmonary vascular permeability index (PVPI).

The association of diastolic arterial pressure and heart rate with mortality in septic shock: a retrospective cohort study

BACKGROUND

The effects of diastolic arterial pressure (DAP) and heart rate (HR) on the prognosis of patients with septic shock are unclear, and whether these effects persist over time is unknown. We aimed to investigate the relationship between exposure to different intensities of DAP and HR over time and mortality at 28 days in patients with septic shock.

METHODS

In this cohort study, we obtained data from the Medical Information Mart for Intensive Care IV, which includes the data of adult patients (≥ 18 years) with septic shock who underwent invasive blood pressure monitoring. We excluded patients who received extracorporeal membrane oxygenation (ECMO) or glucocorticoids within 48 h of ICU admission. The primary outcome was mortality at 28 days. Piece-wise exponential additive mixed models were used to estimate the strength of the associations over time.

RESULTS

In total, 4959 patients were finally included. The median length of stay in the ICU was 3.2 days (IQR: 1.5-7.1 days), and the mortality in the ICU was 12.9%, with a total mortality at 28 days of 15.9%. After adjustment for baseline and time-dependent confounders, both daily time-weighted average (TWA) DAP and HR were associated with increased mortality at 28 days and strong association, mainly in the early to mid-stages of the disease. The results showed that mortality in patients with septic shock was lowest at a DAP of 50-70 mm Hg and an HR of 60-90 beats per minute (bpm). Throughout, a significant increase in the risk of death was found with daily exposure to TWA-DAP ≤ 40 mmHg (hazard ratio 0.99, 95% confidence interval (CI) 0.94-1.03) or TWA-HR ≥ 100 bpm (hazard ratio 1.16, 95% CI 1.1-1.21). Cumulative and interactive effects of harmful exposure (TWA-DAP ≤ 40 mmHg and TWA-HR ≥ 100 bpm) were also observed.

CONCLUSION

The optimal ranges for DAP and HR in patients with septic shock are 50-70 mmHg and 60-90 bpm, respectively. The cumulative and interactive effects of exposure to low DAP (≤ 40 mmHg) and tachycardia (≥ 100 bpm) were associated with an increased risk of death.