What every intensivist should know about the IVC

Assessment of the IVC by point-of-care ultrasound in the context of resuscitation has been a controversial topic in the last decades. Most of the focus had been on its use as a surrogate marker for fluid responsiveness, with results being equivocal. We review its important anatomical aspects as well as the physiological rationale behind ultrasound assessment and propose a new way to do so, as well as explain its central role in the concept of fluid tolerance.

Bedside Ultrasound in the Management of Cardiorenal Syndromes: An Updated Review

BACKGROUND

Cardiorenal syndromes constitute a spectrum of disorders involving heart and kidney dysfunction modulated by a complex interplay of neurohormonal, inflammatory, and hemodynamic derangements. The management of such patients often poses a diagnostic and therapeutic challenge to physicians owing to gaps in understanding of pathophysiology, paucity of objective bedside diagnostic tools, and individual biases.

SUMMARY

In this narrative review, we discuss the role of clinician who performed bedside ultrasound in the management of patients with cardiorenal syndromes. Novel sonographic applications such as venous excess ultrasound score (VExUS) are reviewed in addition to the lung and focused cardiac ultrasound. Further, underrecognized causes of heart failure such as high-flow arteriovenous fistula are discussed.

KEY MESSAGE

Bedside ultrasound allows a comprehensive hemodynamic characterization of cardiorenal syndromes.

Femoral vein pulsatility: a simple tool for venous congestion assessment

BACKGROUND

Femoral vein Doppler (FVD) is simpler than the VExUS score which is a multimodal scoring system based on combination of IVC diameter, hepatic venous Doppler, portal vein pulsatility and renal vein Doppler, may be useful in assessing right ventricular overload and signs of venous congestion. There is limited data on the relationship between FVD and VExUS score.

RESULTS

Adult post-cardiac surgery patients were assessed for venous congestion using the VExUS score and FVD. Agreement between VExUS and FVD was studied using Kappa test, sensitivity, specificity, PPV and NPV for VExUS and FVD was calculated keeping CVP as gold standard. In total, 107 patients were enrolled, with a mean age of 55.67 ± 12.76. The accuracy of VExUS and FVD for detecting venous congestion was 80.37 (95% CI of 71.5 to 87.4) and 74.7 (95% CI of 65.4 to 82.6), respectively. The level of agreement between FVD and VExUS was moderate (Kappa value of 0.62, P < 0.001) while the agreement between FVD and CVP was weak (Kappa value of 0.49, P < 0.001).

CONCLUSION

FVD has good accuracy for detecting venous congestion and shows moderate agreement with VExUS grading. With potentially easier physical accessibility and a shorter learning curve for novices, it may be a simple and valuable tool for assessing venous congestion.

Multi-organ Evaluation of Perfusion and Congestion Using Ultrasound in Patients with Shock

There is increasing evidence on the role of ultrasound in the evaluation of multi-organ hypoperfusion and congestion in patients with cardiocirculatory shock both to identify the underlying pathophysiological mechanism, to drive and monitor the treatment. The cardiac and lung ultrasound are included as integrated multiparametric approach to the very early phase of patients with hemodynamic instability/ cardiogenic shock. Splanchnic ultrasound has been mainly applied in heart failure and predominant circulatory failure. Although poorly validated in the critically ill, many ultrasound parameters have a strong physiological background to support their use in the acute setting either those that apply for heart/lung and for splanchnic organ evaluation. This review summarizes the ultrasonographic parameters that have shown evidence in literature in the diagnostic/therapeutic pathway to define the congestion/perfusion profile of the organs that are involved in the pathophysiological cascade of cardiocirculatory shock.

The Survival of the Surviving Sepsis Campaign

Even well-intentioned policies have great potential to cause harm. This statement is vividly illustrated by the influential, yet controversial, Surviving Sepsis Campaign guidelines and subsequent CMS benchmarks. Despite low-quality evidence, tendentious industry ties, and rebuke from the Infectious Disease Society of America (IDSA), these benchmarks continue to eschew therapy driven by clinician expertise and individual patient needs in favor of mandating an arbitrary, one-size-fits-all approach that suspends clinical judgment and promotes indiscriminate use of treatments that have the potential to cause great harm.

High sensitivity troponin - Six hours is the magic number

BACKGROUND

High sensitivity troponin assays have become widespread for emergency department evaluation of acute chest pain. We assessed if a high sensitivity troponin under the 99th percentile upper reference limit drawn at 6 h or greater from symptom onset could safely rule out acute coronary syndrome in patients who did not meet the rapid rule-out strategy.

METHODS

We conducted a multicenter retrospective study examining emergency department patients with chest pain who did not meet rapid-rule out criteria and were admitted for further evaluation. Among these admitted patients, we assessed the rate of clinically relevant adverse cardiac events (death, cardiac or respiratory arrest, STEMI, or life-threatening arrhythmia) and NSTEMI in patients with high sensitivity troponin less than the 99th percentile value obtained after at least 6 h of chest pain.

RESULTS

Out of 1187 patients admitted, we found 30 clinically relevant adverse cardiac events, all of which occurred in patients admitted for another compelling reason or ischemic ECG. 36 patients had an NSTEMI, of which 33 were identified with high sensitivity troponin greater than 99th percentile upper reference limit within 6 h of chest pain onset. This left 0 clinically relevant adverse cardiac events and 3 NSTEMI among the 429 patients with high sensitivity troponin less than the 99th percentile at 6 h and nonischemic ECG and no other compelling reason for admission.

CONCLUSION

This study assessed patients with chest pain with high sensitivity troponin values between 3 ng/L and the 99th percentile upper reference limit after 6 h of chest pain and found that they have a low rate of clinically relevant adverse cardiac events and NSTEMI.

Lowering platelet count threshold to 10,000/µL for peripherally inserted central catheter placement safely conserves blood products

Despite the low risk of peripherally inserted central catheter (PICC) insertion-related bleeding, the practice of administering prophylactic platelets varies greatly. Limiting unnecessary blood product transfusions reduces transfusion-related adverse events, financial cost, and delays in care. We assessed the impact of lowering prophylactic platelet administration threshold on blood product utilization patterns and bleeding events. This quasi-experimental study was conducted in an urban academic tertiary medical center. The study population included patients with platelet counts ≥ 10,000/µL and < 50,000/µL undergoing PICC placement in 2018 and 2019 when the minimum platelet thresholds were 50,000/µL and 10,000/µL, respectively. The primary outcome was blood product utilization and the secondary outcome was PICC insertion-related bleeding complications. Thirty-five patients using the 10,000/µL (10 K) platelet threshold and 46 patients using the 50,000/µL (50 K) platelet threshold were enrolled. The 50 K group received more platelets before PICC insertion (0.870 ± 0.885 and 0.143 ± 0.430 pools of platelets-per-person, p < 0.001). No patients experienced clinically significant bleeding. Immediately following PICC insertion, minor bleeding occurred in five patients (two [4.3%] and three [8.6%] in the 50 K and 10 K groups, respectively). Bleeding rates between the two cohorts did not differ (p = 0.647). Lowering the minimum platelet threshold from 50,000/µL to 10,000/µL resulted in less prophylactic platelet and total blood product administration with no appreciable difference in PICC insertion-related bleeding.

Clinical applications of the venous excess ultrasound (VExUS) score: conceptual review and case series

The importance of functional right ventricular failure and resultant splanchnic venous congestion has long been under-appreciated and is difficult to assess by traditional physical examination and standard diagnostic imaging. The recent development of the venous excess ultrasound score (VExUS) and growth of point-of-care ultrasound in the last decade has made for a potentially very useful clinical tool. We review the rationale for its use in several pathologies and illustrate with several clinical cases where VExUS was pivotal in clinical management.

The use of venous Doppler to predict adverse kidney events in a general ICU cohort

Background

Changes in Doppler flow patterns of hepatic veins (HV), portal vein (PV) and intra-renal veins (RV) reflect right atrial pressure and venous congestion; the feasibility of obtaining these assessments and the clinical relevance of the findings is unknown in a general ICU population. This study compares the morphology of HV, PV and RV waveform abnormalities in prediction of major adverse kidney events at 30 days (MAKE30) in critically ill patients.

Study design and methods

We conducted a prospective observational study enrolling adult patients within 24 h of admission to the ICU. Patients underwent an ultrasound evaluation of the HV, PV and RV. We compared the rate of MAKE-30 events in patients with and without venous flow abnormalities in the hepatic, portal and intra-renal veins. The HV was considered abnormal if S to D wave reversal was present. The PV was considered abnormal if the portal pulsatility index (PPI) was greater than 30%. We also examined PPI as a continuous variable to assess whether small changes in portal vein flow was a clinically important marker of venous congestion.

Results

From January 2019 to June 2019, we enrolled 114 patients. HV abnormalities demonstrate an odds ratio of 4.0 (95% CI 1.4–11.2). PV as a dichotomous outcome is associated with an increased odds ratio of MAKE-30 but fails to reach statistical significance (OR 2.3 95% CI 0.87–5.96), but when examined as a continuous variable it demonstrates an odds ratio of 1.03 (95% CI 1.00–1.06). RV Doppler flow abnormalities are not associated with an increase in the rate of MAKE-30

Interpretation

Obtaining hepatic, portal and renal venous Doppler assessments in critically ill ICU patients are feasible. Abnormalities in hepatic and portal venous Doppler are associated with an increase in MAKE-30. Further research is needed to determine if venous Doppler assessments can be useful measures in assessing right-sided venous congestion in critically ill patients.

Fluid Resuscitation: History, Physiology, and Modern Fluid Resuscitation Strategies

Intravenous (IV) fluids are among the most common interventions performed in the emergency department. They are at times lifesaving, but if used recklessly can be harmful. Given their ubiquity, it is important to understand the history, physiology, and current strategies that govern the use of IV fluids during the resuscitation of the critically ill.

Designing dementia treatment studies: Diagnosis, efficacy criteria, and duration

Development of treatments for dementia is beset by special problems in defining the diagnosis, establishing efficacy criteria, and specifying the necessary duration of study. There is need for agreement among clinicians and scientists on diagnostic subgroups of dementia. Similarly, there is a need for harmonization of the regulatory guidelines in Europe, Japan, and the United States regarding the decision set of variables on which to base efficacy claims. The duration of trials must be based upon the intended claim: transient symptomatic benefit, maintained symptomatic benefit, or a therapeutic effect on disease progression. Claims other than transient benefit require long-term trials, suggested to be of at least six months in duration. Problems with long-term studies include slow patient accrual, high dropout rates, changing milieu, low return on investment, and lack of unanimity regarding regulatory requirements. Regulatory authorities must come to some accord, consonant with current clinical/scientific wisdom and consensus, regarding diagnosis, efficacy criteria, and feasible study duration, in order to attract continued sponsor investment in the development of antidementia treatments.

Quantifying systemic congestion with Point-Of-Care ultrasound: development of the venous excess ultrasound grading system

Background

Organ congestion is a mediator of adverse outcomes in critically ill patients. Point-Of-Care ultrasound (POCUS) is widely available and could enable clinicians to detect signs of venous congestion at the bedside. The aim of this study was to develop several grading system prototypes using POCUS and to determine their respective ability to predict acute kidney injury (AKI) after cardiac surgery. This is a post-hoc analysis of a single-center prospective study in 145 patients undergoing cardiac surgery for which repeated daily measurements of hepatic, portal, intra-renal vein Doppler and inferior vena cava (IVC) ultrasound were performed during the first 72 h after surgery. Five prototypes of venous excess ultrasound (VExUS) grading system combining multiple ultrasound markers were developed.

Results

The association between each score and AKI was assessed using time-dependant Cox models as well as conventional performance measures of diagnostic testing. A total of 706 ultrasound assessments were analyzed. We found that defining severe venous congestion as the presence of severe flow abnormalities in multiple Doppler patterns with a dilated IVC (≥ 2 cm) showed the strongest association with the development of subsequent AKI compared with other combinations (HR: 3.69 CI 1.65–8.24 p = 0.001). The association remained significant after adjustment for baseline risk of AKI and vasopressor/inotropic support (HR: 2.82 CI 1.21–6.55 p = 0.02). Furthermore, this severe VExUS grade offered a useful positive likelihood ratio (+LR: 6.37 CI 2.19–18.50) when detected at ICU admission, which outperformed central venous pressure measurements.

Conclusions

The combination of multiple POCUS markers may identify clinically significant venous congestion.

The origins of the Lacto-Bolo reflex: the mythology of lactate in sepsis

The use of lactate as a marker of the severity of circulatory shock was popularized by Dr. Weil in the 1970's. Dr. Weil promoted the idea that blood lactate concentration increased in circulatory shock due to anaerobic metabolism following decreased oxygen delivery. This concept becomes entrenched with 1992 ACCP/SCCM consensus conference definition of sepsis. Since then, the central role of lactate in the definition and management of septic shock has only been expanded and become more ingrained. This review will discuss the wisdom of such an approach, an updated model describing the origins of hyperlactatemia in sepsis, and how such improvements in our knowledge of the underlying physiology should change our approach to resuscitation in patients presenting with septic shock.

Anatomy of resuscitative care unit: expanding the borders of traditional intensive care units

Resuscitation lacks a place in the hospital to call its own. Specialised intensive care units, though excellent at providing longitudinal critical care, often lack the flexibility to adapt to fluctuating critical care needs. We offer the resuscitative care unit as a potential solution to ensure that patients receive appropriate care during the most critical hours of their illnesses. These units offer an infrastructure for resuscitation and can meet the changing needs of their institutions.

Age-Dependent Phenotypic Expression of a Pattern Dystrophy of the Retina

We studied a family with pattern dystrophy of the retina (PDR) in order to elucidate the clinical course of the disorder, relations between the different forms, and the mode of inheritance. Thirty-nine family members, representing three generations, underwent a thorough ophthalmological examination, with fluorescein angiography whenever a macular abnormality was suspected. Of family members over the age of 32 years, 46.7% showed signs of PDR. We classified the clinical forms of PDR in this family into four types: minimal lesion, pseudovitelliform type, butterfly-spider type, and late-stage lesion. These forms were predominant in the order cited in age groups 31-40 years, 41-50, 51-60, and > 60 years. Significant visual loss occurred only after the age of 50 years, when 8 of 14 eyes had visual acuity of less than 20/25. Inheritance was autosomal dominant. PDR presented different clinical forms in members of this family, and in successive age classes patterns of increasing severity prevailed. Thus, the different phenotypic forms apparently represent transient stages related to the age of the patient.

Relationship Between the Subcostal and Right Lateral Ultrasound Views of Inferior Vena Cava Collapse: Implications for Clinical Use of Ultrasonography

BACKGROUND

The collapsibility index of the inferior vena cava is traditionally visualized from the subcostal region in the sagittal plane, referred to here as cIVC_SS. Alternatively, the collapsibility index of the inferior vena cava can be visualized from the right midaxillary line in the coronal plane, referred to here as cIVC_RC. It is unclear whether values of cIVC_RC are comparable with values of cIVC_SS because the inferior vena cava collapses asymmetrically into an elliptical form, quantified as the flat ratio of the inferior vena cava (F-IVC). This study aimed (1) to establish if cIVC_RC is concordant or discordant to cIVC_SS, and (2) to describe how this concordance or discordance is related to F-IVC.

METHODS

This single-center cross-sectional study enrolled 110 spontaneously breathing patients. Values of cIVC_RC were compared with cIVC_SS. Performance of cIVC_RC ≥ 42% in predicting fluid responsiveness, defined as cIVC_SS ≥ 42%, was assessed. F-IVC was also correlated to the difference between cIVC_SS and cIVC_RC.

RESULTS

cIVC_RC ≥ 42% was 61.5% sensitive (95% CI, 31.58%-86.14%) and 67.1% specific (95% CI, 55.81%-77.06%) for predicting cIVC_SS ≥ 42%. cIVC_RC underestimated cIVC_SS. The degree of discordance between cIVC_RC and cIVC_SS was proportional to the value of F-IVC.

CONCLUSIONS

cIVC_RC and cIVC_SS measures are discordant, where cIVC_RC underestimates cIVC_SS. The degree of discordance is directly proportional to the value of F-IVC. Therefore, we recommend that cIVC_RC ≥ 42% be used to rule in, but not to rule out, fluid responsivity. Wherever possible, F-IVC should be assessed to understand the clinical relevance of cIVC_RC.

Psychological Skills to Improve Emergency Care Providers' Performance Under Stress

Stress experienced by emergency medical providers during the resuscitation of critically ill or injured patients can cause cognitive and technical performance to deteriorate. Psychological skills training offers a reasonable and easily implemented solution to this problem. In this article, a specific set of 4 performance-enhancing psychological skills is introduced: breathe, talk, see, and focus. These skills comprise breathing techniques, positive self-talk, visualization or mental practice, and implementing a focus "trigger word." The evidence supporting these concepts in various domains is reviewed and specific methods for adapting them to the environment of resuscitation and emergency medicine are provided.

Quick SOFA Scores Predict Mortality in Adult Emergency Department Patients With and Without Suspected Infection

STUDY OBJECTIVE

The Quick Sequential Organ Failure Assessment (qSOFA) score (composed of respiratory rate ≥22 breaths/min, systolic blood pressure ≤100 mm Hg, and altered mental status) may identify patients with infection who are at risk of complications. We determined the association between qSOFA scores and outcomes in adult emergency department (ED) patients with and without suspected infection.

METHODS

We performed a single-site, retrospective review of adult ED patients between January 2014 and March 2015. Patients triaged to fast-track, dentistry, psychiatry, and labor and delivery were excluded. qSOFA scores were calculated with simultaneous vital signs and Modified Early Warning System scores. Patients receiving intravenous antibiotics were presumed to have suspected infection. Univariate and multivariate analyses were performed to explore the association between qSOFA scores and inpatient mortality, admission, and length of stay. Receiver operating characteristics curve analysis and c statistics were also calculated for ICU admission and mortality.

RESULTS

We included 22,530 patients. Mean age was 54 years (SD 21 years), 53% were women, 45% were admitted, and mortality rate was 1.6%. qSOFA scores were associated with mortality (0 [0.6%], 1 [2.8%], 2 [12.8%], and 3 [25.0%]), ICU admission (0 [5.1%], 1 [10.5%], 2 [20.8%], and 3 [27.4%]), and hospital length of stay (0 [123 hours], 1 [163 hours], 2 [225 hours], and 3 [237 hours]). Adjusted rates were also associated with qSOFA. The c statistics for mortality in patients with and without suspected infection were similarly high (0.75 [95% confidence interval 0.71 to 0.78) and 0.70 (95% confidence interval 0.65 to 0.74), respectively.

CONCLUSION

qSOFA scores were associated with inpatient mortality, admission, ICU admission, and hospital length of stay in adult ED patients likely to be admitted both with and without suspected infection and may be useful in predicting outcomes.