A Systemic Review on the Diagnostic Accuracy of Point-of-Care Ultrasound in Patients With Undifferentiated Shock in the Emergency Department

Diagnostic Accuracy of Ultrasound in Intensive Care Patients with Undifferentiated Shock: A Systematic Review and Meta-analysis

Purpose

This systematic review aimed to assess the accuracy of ultrasound in diagnosing shock types among intensive care patients.

Materials and methods

A comprehensive search of PubMed, Embase, Scopus, Cochrane Central Register, and Google Scholar was conducted for controlled trials published up to June 2023. Two intensivists independently screened articles for full-text reviews and abstracts, evaluating study quality using the QUADAS-2 tool. Prospective studies assessing ultrasound for diagnosing shock types in critically ill patients with undifferentiated shock were included.

Results

Among 7287 articles identified, four met the inclusion criteria for meta-analysis. Pooled positive likelihood ratios were 8.8 (95% CI: 2.4-32.37) for distributive shock and 137.56 (95% CI: 27.76-681.64) for obstructive shock. Summary receiver operating characteristic (SROC) curves showed an area under the curve (AUC) of 0.99 for cardiogenic and obstructive shock, 0.5 for hypovolemic and mixed shock, and 0.76 for distributive shock. Pooled negative likelihood ratios ranged from 0.05 (95% CI: 0.010 to 0.24) for cardiogenic shock to 0.22 (95% CI: 0.127-0.38) for mixed-etiology shock.

Conclusion

Ultrasound demonstrates high accuracy in diagnosing obstructive and cardiogenic shock among intensive care patients with undifferentiated shock. However, its utility for other shock types appears limited.

How to cite this article

Karigowda L, Gupta B, Elkady H, Deshpande K. Diagnostic Accuracy of Ultrasound in Intensive Care Patients with Undifferentiated Shock: A Systematic Review and Meta-analysis. Indian J Crit Care Med 2024;28(12):1159-1169.

The association between integrating echocardiography use in the management of septic shock patients and outcomes in the intensive care unit: a systematic review and meta-analysis

OBJECTIVES

Septic shock in critically ill patients can increases morbidity and mortality. We aimed to study the effect on outcomes when integrating point of care (POC) echocardiography in the management of septic shock patients in the Intensive Care Unit (ICU) who are being treated according to the Surviving Sepsis Campaign (SSC) guidelines.

METHODS

An electronic search of MEDLINE through PubMed, clinical trials.gov and google scholar was conducted for the period from January 1990-January 2024 to identify studies of septic shock adult and pediatric patients in the ICU managed according to SSC guidelines with or without POC echocardiography. Three reviewers extracted data independent of each other. Cochrane collaboration tool was used for bias assessment. Random effect meta-analysis used to pool data.

RESULTS

A total of 1701 articles identified. Seven studies included in the final report with a total of 3885 patients. POC echocardiography guided septic shock management was associated with lower in-hospital and 28-day mortality (sOR = 0.82 [95%CI: 0.71-0.95], p = 0.01), more frequent initiation of inotropic support (sOR = 2.42 [95%CI 1.92-3.03], p < 0.0001) and shorter time to achieve lactate clearance (SMD = - 0.87 h [95%CI - 1.23 h to - 0.51 h], p < 0.0001). Summary estimates did not achieve significance for effect of POC echocardiography on 24-h fluid intake (SMD = - 2.11 ml [95%CI - 5.93 ml to 1.72 ml], p = 0.28) on mechanical ventilation-free days (SMD = 0.03 days [95%CI - 0.04 to 0.10], p = 0.94). Shock reversal time analysis was less meaningful due to the small number of studies reporting outcome.

CONCLUSIONS

POC echocardiography guided management in septic shock patients in the ICU can lead to a decrease in mortality, increase in initiation of inotropic support, and a decrease in lactate clearance time. Larger cohort studies and data collection and analysis are needed for further understanding and optimizing standardization of protocols for POC echocardiography use in septic shock patients in the ICU.

Does Point-of-Care Ultrasound Affect Fluid Resuscitation Volume in Patients with Septic Shock: A Retrospective Review

Background

Fixed, large volume resuscitation with intravenous fluids (IVFs) in septic shock can cause inadvertent hypervolemia, increased medical interventions, and death when unguided by point-of-care ultrasound (POCUS). The primary study objective was to evaluate whether total IVF volume differs for emergency department (ED) septic shock patients receiving POCUS versus no POCUS.

Methods

We conducted a retrospective observational cohort study from 7/1/2018 to 8/31/2021 of atraumatic adult ED patients with septic shock. We agreed upon a priori variables and defined septic shock as lactate ≥4 and hypotension (SBP <90 or MAP <65). A sample size of 300 patients would provide 85% power to detect an IVF difference of 500 milliliters between POCUS and non-POCUS cohorts. Data are reported as frequencies, median (IQR), and associations from bivariate logistic models.

Results

304 patients met criteria and 26% (78/304) underwent POCUS. Cardiac POCUS demonstrated reduced ejection fraction in 15.4% of patients. Lung ultrasound showed normal findings in 53% of patients. The POCUS vs. non-POCUS cohorts had statistically significant differences for the following variables: higher median lactate (6.7 [IQR 5.2-8.7] vs. 5.6], p = 0.003), lower systolic blood pressure (77.5 [IQR 61-86] vs. 85.0, p < 0.001), more vasopressor use (51% vs. 34%, p = 0.006), and more positive pressure ventilation (38% vs. 24%, p = 0.017). However, there were no statistically significant differences between POCUS and non-POCUS cohorts in total IVF volume ml/kg (33.02 vs. 32.1, p = 0.47), new oxygen requirement (68% vs. 59%, p = 0.16), ED death (3% vs. 4%, p = 0.15), or hospital death (31% vs. 27%, p = 0.48). There were similar distributions of lactate, total fluids, and vasopressors in patients with CHF and severe renal failure.

Conclusions

Among ED patients with septic shock, POCUS was more likely to be used in sicker patients. Patients who had POCUS were given similar volume of crystalloids although these patients were more critically ill. There were no differences in new oxygen requirement or mortality in the POCUS group compared to the non-POCUS group.

Point-of-Care Ultrasound: A Multimodal Tool for the Management of Sepsis in the Emergency Department

Sepsis and septic shock are life-threatening emergencies associated with increased morbidity and mortality. Hence, early diagnosis and management of both conditions is of paramount importance. Point-of-care ultrasound (POCUS) is a cost-effective and safe imaging modality performed at the bedside, which has rapidly emerged as an excellent multimodal tool and has been gradually incorporated as an adjunct to physical examination in order to facilitate evaluation, diagnosis and management. In sepsis, POCUS can assist in the evaluation of undifferentiated sepsis, while, in cases of shock, it can contribute to the differential diagnosis of other types of shock, thus facilitating the decision-making process. Other potential benefits of POCUS include prompt identification and control of the source of infection, as well as close haemodynamic and treatment monitoring. The aim of this review is to determine and highlight the role of POCUS in the evaluation, diagnosis, treatment and monitoring of the septic patient. Future research should focus on developing and implementing a well-defined algorithmic approach for the POCUS-guided management of sepsis in the emergency department setting given its unequivocal utility as a multimodal tool for the overall evaluation and management of the septic patient.

Intra-and inter-observer variability of point of care ultrasound measurements to evaluate hemodynamic parameters in healthy volunteers

BACKGROUND

Point-of-care ultrasound (POCUS) is a valuable tool for assessing the hemodynamic status of acute patients. Even though POCUS often uses a qualitative approach, quantitative measurements have potential advantages in evaluating hemodynamic status. Several quantitative ultrasound parameters can be used to assess the hemodynamic status and cardiac function. However, only limited data on the feasibility and reliability of the quantitative hemodynamic measurements in the point-of-care setting are available. This study investigated the intra- and inter-observer variability of PoCUS measurements of quantitative hemodynamic parameters in healthy volunteers.

METHODS

In this prospective observational study, three sonographers performed three repeated measurements of eight different hemodynamic parameters in healthy subjects. An expert panel of two experienced sonographers evaluated the images' quality. The repeatability (intra-observer variability) was determined by calculating the coefficient of variation (CV) between the separate measurements for each observer. The reproducibility (inter-observer variability) was assessed by determining the intra-class correlation coefficient (ICC).

RESULTS

32 subjects were included in this study, on whom, in total, 1502 images were obtained for analysis. All parameters were in a normal physiological range. Stroke volume (SV), cardiac output (CO), and inferior vena cava diameter (IVC-D) showed high repeatability (CV under 10%) and substantial reproducibility (ICC 0.61-0.80). The other parameters had only moderate repeatability and reproducibility.

CONCLUSIONS

We demonstrated good inter-observer reproducibility and good intra-observer repeatability for CO, SV and IVC-D taken in healthy subjects by emergency care physicians.

The Incremental Role of Multiorgan Point-of-Care Ultrasounds in the Emergency Setting

Point-of-care ultrasonography (POCUS) represents a goal-directed ultrasound examination performed by clinicians directly involved in patient healthcare. POCUS has been widely used in emergency departments, where US exams allow physicians to make quick diagnoses and to recognize early life-threatening conditions which require prompt interventions. Although initially meant for the real-time evaluation of cardiovascular and respiratory pathologies, its use has been extended to a wide range of clinical applications, such as screening for deep-vein thrombosis and trauma, abdominal ultrasonography of the right upper quadrant and appendix, and guidance for invasive procedures. Moreover, recently, bedside ultrasounds have been used to evaluate the fluid balance and to guide decongestive therapy in acutely decompensated heart failure. The aim of the present review was to discuss the most common applications of POCUS in the emergency setting.

Emerging concepts in heart failure management and treatment: focus on point-of-care ultrasound in cardiogenic shock

Point-of-care ultrasound (POCUS) plays a strategic role in the diagnostic and therapeutic evaluation of critically ill patients and, especially, in those who are haemodynamically unstable. In this context, POCUS allows a more precise identification of the cause, its differential diagnosis, the eventual coexistence with another entity and, finally, guiding of the therapeutic approach. It implies a portable use of ultrasound in acute settings covering different specified protocols, such as echocardiography, vascular, lung or abdominal ultrasound. This article reviews POCUS application in the emergency department or the intensive care unit, focused on severely compromised patients with cardiogenic shock with an emergent bedside assessment. Considering the high mortality rate of this entity, POCUS provides the intensivist/clinician with an appropriate tool for accurate diagnoses and a timely management plan. The authors propose practical algorithms for the diagnosis of patients using POCUS in these settings. This article is part of the Emerging concepts in heart failure management and treatment Special Issue: https://www.drugsincontext.com/special_issues/emerging-concepts-in-heart-failure-management-and-treatment.

Point‑of‑Care Ultrasound - accuracy, education

A review article discussing the reliability of Point-of-Care ultrasound and education in this method in various fields of medicine.