Accuracy of ultrasonography performed by critical care physicians for the diagnosis of DVT

Defining Intensivists: A Retrospective Analysis of the Published Studies in the United States, 2010-2020

OBJECTIVES

The Society of Critical Care Medicine last published an intensivist definition in 1992. Subsequently, there have been many publications relating to intensivists. Our purpose is to assess how contemporary studies define intensivist physicians.

DESIGN

Systematic search of PubMed, Embase, and Web of Science (2010-2020) for publication titles with the terms intensivist, and critical care or intensive care physician, specialist, or consultant. We included studies focusing on adult U.S. intensivists and excluded non-data-driven reports, non-U.S. publications, and pediatric or neonatal ICU reports. We aggregated the study title intensivist nomenclatures and parsed Introduction and Method sections to discern the text used to define intensivists. Fourteen parameters were found and grouped into five definitional categories: A) No definition, B) Background training and certification, C) Works in ICU, D) Staffing, and E) Database related. Each study was re-evaluated against these parameters and grouped into three definitional classes (single, multiple, or no definition). The prevalence of each parameter is compared between groups using Fisher exact test.

SETTING

U.S. adult ICUs and databases.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 657 studies, 105 (16%) met inclusion criteria. Within the study titles, 17 phrases were used to describe an intensivist; these were categorized as intensivist in 61 titles (58%), specialty intensivist in 30 titles (29%), and ICU/critical care physician in 14 titles (13%). Thirty-one studies (30%) used a single parameter (B-E) as their definition, 63 studies (60%) used more than one parameter (B-E) as their definition, and 11 studies (10%) had no definition (A). The most common parameter "Works in ICU" (C) in 52 studies (50%) was more likely to be used in conjunction with other parameters rather than as a standalone parameter (multiple parameters vs single-parameter studies; 73% vs 17%; p < 0.0001).

CONCLUSIONS

There was no consistency of intensivist nomenclature or definitions in contemporary adult intensivist studies in the United States.

Point-of-Care Ultrasound: A Moving Picture Is Worth a Thousand Tests

The effective utilization of point-of-care ultrasound may decrease the utilization of conventional diagnostic modalities. This review describes the various pathologies that can be effectively and rapidly identified with point-of-care cardiac, lung, abdominal, vascular airway, and ocular ultrasonography.

Integrated Assessment of Heart, Lung and Lower Extremity Veins Using Hand-Held Ultrasound Device in COVID-19 Patients: Feasibility and Clinical Application

The emergence of the COVID-19 pandemic caused a significant shortage of medical personnel and the prioritization of life-saving procedures on internal medicine and cardiology wards. Thus, the cost- and time-effectiveness of each procedure proved vital. Implementing elements of imaging diagnostics into the physical examination of COVID-19 patients could prove beneficial to the treatment process, providing important clinical data at the moment of admission. Sixty-three patients with positive COVID-19 test results were enrolled into our study and underwent physical examination expanded with a handheld ultrasound device (HUD)-performed bedside assessment included: right ventricle measurement, visual and automated LVEF assessment, four-point compression ultrasound test (CUS) of lower extremities and lung ultrasound. Routine testing consisting of computed-tomography chest scanning, CT-pulmonary angiogram and full echocardiography performed on a high-end stationary device was completed in the following 24 h. Lung abnormalities characteristic for COVID-19 were detected in CT in 53 (84%) patients. The sensitivity and specificity of bedside HUD examination for detecting lung pathologies was 0.92 and 0.90, respectively. Increased number of B-lines had a sensitivity of 0.81, specificity 0.83 for the ground glass symptom in CT examination (AUC 0.82; p < 0.0001); pleural thickening sensitivity 0.95, specificity 0.88 (AUC 0.91, p < 0.0001); lung consolidations sensitivity 0.71, specificity 0.86 (AUC 0.79, p < 0.0001). In 20 patients (32%), pulmonary embolism was confirmed. RV was dilated in HUD examination in 27 patients (43%), CUS was positive in two patients. During HUD examination, software-derived LV function analysis failed to measure LVEF in 29 (46%) cases. HUD proved its potential as the first-line modality for the collection of heart-lung-vein imaging information among patients with severe COVID-19. HUD-derived diagnosis was especially effective for the initial assessment of lung involvement. Expectedly, in this group of patients with high prevalence of severe pneumonia, HUD-diagnosed RV enlargement had moderate predictive value and the option to simultaneously detect lower limb venous thrombosis was clinically attractive. Although most of the LV images were suitable for the visual assessment of LVEF, an AI-enhanced software algorithm failed in almost 50% of the study population.

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.

Point-of-Care Ultrasound in the Intensive Care Unit: Applications, Limitations, and the Evolution of Clinical Practice

The use of point-of-care ultrasonography in the intensive care unit has been rapidly advancing over the past 20 years. This review will provide a broad overview of the discipline spanning lung ultrasonography to advanced critical care echocardiography. It will highlight new research that questions the utility of the inferior vena cava for determining volume responsiveness and will introduce the reader to cutting-edge technology including artificial intelligence, which is likely to revolutionize ultrasound teaching and image interpretation, increasing the reach of this modality for the frontline clinician.

The wedge sign: A possible lung ultrasound sign for pulmonary thromboembolism

OBJECTIVE

To describe the finding of the lung ultrasound (LUS) "wedge sign" in dogs with presumptive pulmonary thromboembolism (PTE).

CASE SERIES SUMMARY

This case series describes 2 dogs with predisposing risk factors of (1) right transvenous pacemaker terminating in its right ventricle, severe protein-losing nephropathy, and glucocorticoid therapy, and (2) caval syndrome, each having the LUS "wedge sign" in upper lung regions, a sign consistent with pulmonary infarction and peripheral PTE.

NEW OR UNIQUE INFORMATION PROVIDED

Historically, the diagnosis of canine PTE has been made through supportive findings because the gold standard test, computed tomography pulmonary angiography (CTPA), poses limitations. The use of LUS has shown promise in people for detecting PTE, with the advantages of availability, being radiation- and contrast medium-sparing, rapid (<90 s), point-of-care, real-time information. Our cases suggest a possible new first-line approach for suspecting canine PTE by using LUS and the finding of the "wedge sign" in nongravity-dependent caudodorsal and perihilar lung regions.

Ten Influential Point-of-Care Ultrasound Papers: 2021 in Review

The ongoing rapid expansion of point-of-care ultrasound (POCUS) and its corresponding supporting literature leaves the frontline clinician in a difficult position when trying to keep abreast of the latest developments. Our group of POCUS experts has selected ten influential POCUS-related papers from the past twelve months and provided a short summary of each. Our aim is to give to emergency physicians, intensivists, and other acute care providers key information, helping them to keep up to date on rapidly evolving POCUS literature.

Thromboembolic Events and Role of Point of Care Ultrasound in Hospitalized Covid-19 Patients Needing Intensive Care Unit Admission

BACKGROUND

Covid-19 associated coagulopathy (CAC) is associated with prothrombotic state and thromboembolism. However, true incidence of thromboembolic events is difficult to determine in the ICU setting. The aim of our study was to investigate the cumulative incidence of thromboembolic events in Covid-19 patients needing intensive care unit (ICU) admission and assessing the utility of point of care ultrasound (POCUS) to screen for and diagnose lower extremity deep venous thrombosis (DVT).

METHODS

We conducted a prospective observational study between April 22nd and May 26th, 2020 where all adult patients with the diagnosis of Covid-19 pneumonia admitted to 8 ICUs of Montefiore Medical Center were included. POCUS exam was performed on all patients at day 1 of ICU admission and at day 7 and 14 after the first exam.

RESULTS

The primary outcome was to study the cumulative incidence of thromboembolic events in Covid-19 patients needing ICU admission. A total of 107 patients were included. All patients got POCUS exam on day 1 in the ICU, 62% got day 7 and 41% got day 14 exam. POCUS diagnosed 17 lower extremity DVTs on day 1, 3 new on day 7 and 1 new on day 14. Forty patients developed 52 thromboembolic events, with the rate of 37.3%. We found a high 45-day cumulative incidence of thromboembolic events of 37% and a high 45-day cumulative incidence of lower and upper extremity DVT of 21% and 10% respectively. Twelve (30%) patients had failure of therapeutic anticoagulation. Occurrence of a thromboembolic event was not associated with a higher risk of mortality (HR 1.08, p value = .81).

CONCLUSIONS

Covid-19 patients in ICU have a high cumulative incidence of thromboembolic events, but not associated with higher mortality. POCUS is an excellent tool to help screen and diagnose DVT during a pandemic.

Right Ventricle Dilation Detected on Point-of-Care Ultrasound Is a Predictor of Poor Outcomes in Critically Ill Patients With COVID-19

Background

During the COVID-19 pandemic, the need for judicious use of diagnostic tests and to limit personnel exposure has led to increased use and dependence on point-of-care ultrasound (POCUS) examinations. We reviewed POCUS findings in patients admitted to the intensive care unit (ICU) for acute respiratory failure with COVID-19 and correlated the findings to severity of illness and 30-day outcomes.

Methods

Patients admitted to the ICU in March and April 2020 were reviewed for inclusion (acute hypoxemic respiratory failure secondary to COVID-19 pneumonia; documentation of POCUS findings).

Results

Forty-three patients met inclusion criteria. B lines and pleural thickening were associated with a lower PaO₂/FiO₂ by 71 (P = .005; adjusted R ² = 0.24). Right ventricle (RV) dilation was more common in patients with 30-day mortality (P = .02) and was a predictor of mortality when adjusted for hypertension, diabetes mellitus, and age (odds ratio, 12.0; P = .048). All patients with RV dilation had bilateral B lines with pleural irregularities.

Conclusions

Although lung ultrasound abnormalities are prevalent in patients with severe disease, RV involvement seems to be predictive of outcomes. Further studies are needed to discern the etiology and pathophysiology of RV dilation in COVID-19.

The Utility of Point-of-Care Ultrasound in the Pediatric Intensive Care Unit

Objectives: Point of care ultrasound (POCUS) in adult critical care environments has become the standard of care in many hospitals. A robust literature shows its benefits for both diagnosis and delivery of care. The utility of POCUS in the pediatric intensive care unit (PICU), however, is understudied. This study describes in a series of PICU patients the clinical indications, protocols, findings and impact of pediatric POCUS on clinical management. Design: Retrospective analysis of 200 consecutive POCUS scans performed by a PICU physician. Patients: Pediatric critical care patients who required POCUS scans over a 15-month period. Setting: The pediatric and cardiac ICUs at a tertiary pediatric care center. Interventions: Performance of a POCUS scan by a pediatric critical care attending with advanced training in ultrasonography. Measurement and Main Results: A total of 200 POCUS scans comprised of one or more protocols (lung and pleura, cardiac, abdominal, or vascular diagnostic protocols) were performed on 155 patients over a 15-month period. The protocols used for each scan reflected the clinical question to be answered. These 200 scans included 133 thoracic protocols, 110 cardiac protocols, 77 abdominal protocols, and 4 vascular protocols. In this series, 42% of scans identified pathology that required a change in therapy, 26% confirmed pathology consistent with the ongoing plans for new therapy, and 32% identified pathology that did not result in initiation of a new therapy. Conclusions: POCUS performed by a trained pediatric intensivist provided useful clinical information to guide patient management.

The Use of POCUS to Manage ICU Patients With COVID-19

Since the advent of SARS-CoV-2, the virus that causes COVID-19, clinicians have had to modify how they provide high-value care while mitigating the risk of viral spread. Routine imaging studies have been discouraged due to elevated transmission risk. Patients who have been diagnosed with COVID-19 often have a protracted hospital course with progression of disease. Given the need for close follow-up of patients, we recommend the use of ultrasonography, particularly point-of-care ultrasound (POCUS), to manage patients with COVID-19 through their entire ICU course. POCUS will allow a clinician to evaluate and monitor cardiac and pulmonary function, as well as evaluate for thromboembolic disease, place an endotracheal tube, confirm central venous catheter placement, and rule out a pneumothorax. If a patient improves sufficiently to perform weaning trials, POCUS can also help evaluate readiness for ventilator liberation.

Residual Lung Injury in Patients Recovering From COVID-19 Critical Illness: A Prospective Longitudinal Point-of-Care Lung Ultrasound Study

Scarce data exist regarding the natural history of lung lesions detected on ultrasound in those who survive severe COVID-19 pneumonia.

OBJECTIVE

We performed a prospective analysis of point-of-care ultrasound (POCUS) findings in critically ill COVID-19 patients during and after hospitalization.

METHODS

We enrolled 171 COVID-19 intensive care unit patients. POCUS of the lungs was performed with phased array (2-4 MHz), convex (2-6 MHz) and linear (10-15 MHz) transducers, scanning 12 lung areas. Chest computed tomography angiography was performed to exclude suspected pulmonary embolism. Survivors were clinically and sonographically evaluated during a 4 month period for evidence of residual lung injury. Chest computed tomography angiography and echocardiography were used to exclude pulmonary hypertension (PH) and chest high-resolution-computed-tomography to exclude interstitial lung disease (ILD) in symptomatic survivors.

RESULTS

Cox regression analysis showed that lymphocytopenia (hazard ratio [HR]: 0.88, 95% confidence intervals [CI]: 0.68-0.96, p = .048), increased lactate (HR: 1.17, 95% CI: 0.94-1.46, p = 0.049), and D-dimers (HR: 1.21, 95% CI: 1.03-1.44, p = .03) were mortality predictors. Non-survivors had increased incidence of pulmonary abnormalities (B-lines, pleural line irregularities, and consolidations) compared to survivors (p < .05). During follow-up, POCUS with clinical and laboratory parameters integrated in the semi-quantitative Riyadh-Residual-Lung-Injury scale had sensitivity of 0.82 (95% CI: 0.76-0.89) and specificity of 0.91 (95% CI: 0.94-0.95) in predicting ILD. The prevalence of PH and ILD (non-specific-interstitial-pneumonia) was 7% and 11.8%, respectively.

CONCLUSION

POCUS showed ability to monitor the evolution of severe COVID-19 pneumonia after hospital discharge, supporting its integration in clinical predictive models of residual lung injury.

The Use of Point-of-Care Ultrasound (POCUS) in the Diagnosis of Deep Vein Thrombosis

Acute lower extremity proximal deep venous thrombosis (DVT) requires accurate diagnosis and treatment in order to prevent embolization and other complications. Point-of-care ultrasound (POCUS), a clinician performed, and clinician interpreted bedside ultrasound examination has been increasingly used for DVT evaluation mainly in the urgent and critical care setting, but also in the ambulatory clinics and the medical wards. Studies have demonstrated that POCUS has excellent diagnostic accuracy for acute proximal DVT when performed by well-trained users. However, there is significant heterogeneity among studies on the necessary extent of training and universally acceptable standardized education protocols are needed. In this review, we summarize the evidence that supports the use of POCUS to diagnose acute proximal DVT and focus on methodology and current technology, sensitivity and specificity, pre-test probability and the role of D-dimer, time and resources, education, limitations, and future directions.

Thromboprophylaxis in critically ill patients: balancing on a tightrope

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, is a common and potentially fatal complication in the intensive care unit (ICU). Critically ill patients have some special characteristics that increase the risk for VTE and complicate risk stratification and diagnosis. Given the positive effect of thromboprophylaxis on main outcomes, its use is mandatory in these patients, which is documented by various studies and recommended by all published guidelines. However, anticoagulation management is not an easy issue in clinical practice, as the critical patient may be at high risk for thrombosis or, conversely, at increased risk of bleeding or may balance between thrombotic and bleeding risk. Thrombotic and bleeding risk scoring should be evaluated daily in order to select the appropriate form of thromboprophylaxis. The selection depends on the degree of bleeding risk and the subgroup of ICU patients involved, such as patients with sepsis, acute brain injury, major trauma or coronavirus disease-2019. If there is no bleeding risk or other contraindication, the patient should receive pharmacologic thromboprophylaxis with unfractionated heparin or low molecular weight heparins, weighing the advantages of each agent. If the patient is at high risk of bleeding or there is a contraindication to pharmacologic prophylaxis, he should receive mechanical thromboprophylaxis mainly with intermittent pneumatic compression or graduated compression stockings. Thromboprophylaxis compliance with the guidelines is a prerequisite for moving from theory to practice. Direct oral anticoagulants have been studied in ICU patients and have no place at present in VTE prophylaxis requiring further research.

Diagnosis and Treatment of Deep Vein Thrombosis in the Emergency Department: Results of an Italian Nominal Group Technique Study

Early diagnosis and treatment of deep vein thrombosis (DVT) is a main issue in the Emergency setting. With the aim of assisting clinicians in the diagnosis and the subsequent management of DVT in the Emergency Departments, a Nominal Group Technique (NGT) study was conducted. A panel of 5 Italian experts developed 21 consensus statements based on available evidence and their clinical experience. The agreed consensus statements may assist clinicians in applying the results of clinical studies and clinical experience to routine care settings, providing guidance on all aspects of the risk assessment, prophylaxis, early diagnosis and appropriate treatment of DVT in the EDs.

How I Do It: Point-of-Care Ultrasound for Bedside Diagnosis of Lower Extremity DVT

The point-of-care ultrasound (POCUS) DVT examination can facilitate rapid bedside diagnosis and treatment of lower extremity DVT. Awaiting radiology-performed Doppler ultrasonography and interpretation by radiologists can lead to delays in lifesaving anticoagulation, and the POCUS DVT examination can provide timely diagnostic information in the patient with lower extremity symptoms. This article outlines accepted techniques for the POCUS DVT examination, discusses the historical context from which the current recommendations have evolved, and provides illustrations alongside ultrasound images of relevant venous anatomy to orient the clinician. Finally, common pitfalls and methods to avoid them are described.

2021 John N. Insall Award: Aspirin is effective in preventing propagation of infrapopliteal deep venous thrombosis following total knee arthroplasty

AIMS

The optimal management of an infrapopliteal deep venous thrombosis (IDVT) following total knee arthroplasty (TKA) remains unknown. The risk of DVT propagation and symptom progression must be balanced against potential haemorrhagic complications associated with administration of anticoagulation therapy. The current study reports on a cohort of patients diagnosed with IDVT following TKA who were treated with aspirin, followed closely for development of symptoms, and scanned with ultrasound to determine resolution of IDVT.

METHODS

Among a cohort of 5,078 patients undergoing TKA, 532 patients (695 TKAs, 12.6%) developed an IDVT between 1 January 2014 to 31 December 2019 at a single institution, as diagnosed using Doppler ultrasound at the first postoperative visit. Of the entire cohort of 532 patients with IDVT, 91.4% (486/532) were treated with aspirin (325 mg twice daily) and followed closely. Repeat lower limb ultrasound was performed four weeks later to evaluate the status of IDVT.

RESULTS

Follow-up Doppler ultrasound was performed on 459/486 (94.4%) patients and demonstrated resolution of IDVT in 445/459 cases (96.9%). Doppler diagnosed propagation of IDVT to the popliteal vein had occurred in 10/459 (2.2%) cases. One patient with an IDVT developed a pulmonary embolus six weeks postoperatively.

CONCLUSION

The results of this study demonstrate a low rate of IDVT propagation in patients managed with aspirin. Additionally, no significant bleeding episodes, wound-related complications, or other adverse events were noted from aspirin therapy. Cite this article: Bone Joint J 2021;103-B(6 Supple A):18-22.

Point of care ultrasound screening for deep vein thrombosis in critically ill COVID-19 patients, an observational study

BACKGROUND

Deep vein thrombosis (DVT) is common in critically ill patients with Coronavirus disease 2019 (COVID-19) and may cause fatal pulmonary embolism (PE) prior to diagnosis due to subtle clinical symptoms. The aim of this study was to explore the feasibility of bedside screening for DVT in critically ill COVID-19 patients performed by physicians with limited experience of venous ultrasound. We further aimed to compare inflammation, coagulation and organ dysfunction in patients with and without venous thromboembolism (VTE).

METHODS

This observational study included patients with COVID-19 admitted to the intensive care unit (ICU) of a tertiary hospital in Sweden and screened for DVT with proximal compression ultrasound of the lower extremities between April and July 2020. Screening was performed by ICU residents having received a short online education and one hands-on-session. Pathological screening ultrasound was confirmed by formal ultrasound whereas patients with negative screening underwent formal ultrasound on clinical suspicion. Clinical data, laboratory findings and follow-up were extracted from medical records.

RESULTS

Of 90 eligible patients, 56 were screened by seven ICU residents with no (n = 5) or limited (n = 2) previous experience of DVT ultrasound who performed a median of 4 (IQR 2-19) examinations. Four (7.1%) patients had pathological screening ultrasound of which three (5.6%) were confirmed by formal ultrasound. None of the 52 patients with negative screening ultrasound were diagnosed with DVT during follow-up. Six patients were diagnosed with PE of which four prior to negative screening and two following negative and positive screening respectively. Patients with VTE (n = 8) had higher median peak D-dimer (24.0 (IQR 14.2-50.5) vs. 2.8 (IQR 1.7-7.2) mg/L, p = 0.004), mean peak C-reactive protein (363 (SD 80) vs. 285 (SD 108) mg/L, p = 0.033) and median peak plasma creatinine (288 (IQR 131-328) vs. 94 (IQR 78-131) μmol/L, p = 0.009) compared to patients without VTE (n = 48). Five patients (63%) with VTE received continuous renal replacement therapy compared to six patients (13%) without VTE (p = 0.005).

CONCLUSION

ICU residents with no or limited experience could detect DVT with ultrasound in critically ill COVID-19 patients following a short education. VTE was associated with kidney dysfunction and features of hyperinflammation and hypercoagulation.

TRIAL REGISTRATION

ClinicalTrials ID: NCT04316884 . Registered 20 March 2020.

Prospective Longitudinal Evaluation of Point-of-Care Lung Ultrasound in Critically Ill Patients With Severe COVID-19 Pneumonia

OBJECTIVES

To perform a prospective longitudinal analysis of lung ultrasound findings in critically ill patients with coronavirus disease 2019 (COVID-19).

METHODS

Eighty-nine intensive care unit (ICU) patients with confirmed COVID-19 were prospectively enrolled and tracked. Point-of-care ultrasound (POCUS) examinations were performed with phased array, convex, and linear transducers using portable machines. The thorax was scanned in 12 lung areas: anterior, lateral, and posterior (superior/inferior) bilaterally. Lower limbs were scanned for deep venous thrombosis and chest computed tomographic angiography was performed to exclude suspected pulmonary embolism (PE). Follow-up POCUS was performed weekly and before hospital discharge.

RESULTS

Patients were predominantly male (84.2%), with a median age of 43 years. The median duration of mechanical ventilation was 17 (interquartile range, 10-22) days; the ICU length of stay was 22 (interquartile range, 20.2-25.2) days; and the 28-day mortality rate was 28.1%. On ICU admission, POCUS detected bilateral irregular pleural lines (78.6%) with accompanying confluent and separate B-lines (100%), variable consolidations (61.7%), and pleural and cardiac effusions (22.4% and 13.4%, respectively). These findings appeared to signify a late stage of COVID-19 pneumonia. Deep venous thrombosis was identified in 16.8% of patients, whereas chest computed tomographic angiography confirmed PE in 24.7% of patients. Five to six weeks after ICU admission, follow-up POCUS examinations detected significantly lower rates (P < .05) of lung abnormalities in survivors.

CONCLUSIONS

Point-of-care ultrasound depicted B-lines, pleural line irregularities, and variable consolidations. Lung ultrasound findings were significantly decreased by ICU discharge, suggesting persistent but slow resolution of at least some COVID-19 lung lesions. Although POCUS identified deep venous thrombosis in less than 20% of patients at the bedside, nearly one-fourth of all patients were found to have computed tomography-proven PE.

Point-of-Care Ultrasound (POCUS) for the Cardiothoracic Anesthesiologist

Point-of-Care Ultrasound (POCUS) is a valuable bedside diagnostic tool for a variety of expeditious clinical assessments or as guidance for a multitude of acute care procedures. Varying aspects of nearly all organ systems can be evaluated using POCUS and, with the increasing availability of affordable ultrasound systems over the past decade, many now refer to POCUS as the 21^st-century stethoscope. With the current available and growing evidence for the clinical value of POCUS, its utility across the perioperative arena adds enormous benefit to clinical decision-making. Cardiothoracic anesthesiologists routinely have used portable ultrasound systems for nearly as long as the technology has been available, making POCUS applications a natural extension of existing cardiothoracic anesthesia practice. This narrative review presents a broad discussion of the utility of POCUS for the cardiothoracic anesthesiologist in varying perioperative contexts, including the preoperative clinic, the operating room (OR), intensive care unit (ICU), and others. Furthermore, POCUS-related education, competence, and certification are addressed.

Prevention, diagnosis, and management of venous thromboembolism in the critically ill surgical and trauma patient

PURPOSE OF REVIEW

Venous thromboembolism (VTE), which encompasses deep vein thrombosis and pulmonary embolism, is common among trauma patients and critically ill surgical patients admitted to the ICU. Critical care surgical patients are at an extremely high risk for VTE and the related morbidity and mortality associated with it. The present review aims to provide an overview of the importance of identifying risk factors, prescribing effective prohylaxis, accurate diagnosis, and timely appropriate treatment for trauma and critically ill surgical patients with VTE in the ICU.

RECENT FINDINGS

VTE is a healthcare burden among critically ill surgical patients that is mostly preventable through adherence to prophylactic protocols that aim to recognize VTE risk factors while simultaneously providing guidance to appropriate timing and administration prophylaxis regimens. Newer pharmacologic therapies for prophylaxis and treatment, diagnostic modalities, and indications for therapy of VTE have continued to evolve.

SUMMARY

Critical care surgical and trauma patients represent a population that are at a heightened risk for VTE and associated complications. Appropriate screening, prevention strategies, accurate diagnosis, and timely administration of appropriate treatment must be utilized to reduce morbidity and mortality.

A preliminary study of intensivist-performed DVT ultrasound screening in trauma ICU patients (APSIT Study)

Background

Multiple screening Duplex ultrasound scans (DUS) are performed in trauma patients at high risk of deep vein thrombosis (DVT) in the intensive care unit (ICU). Intensive care physician performed compression ultrasound (IP-CUS) has shown promise as a diagnostic test for DVT in a non-trauma setting. Whether IP-CUS can be used as a screening test in trauma patients is unknown. Our study aimed to assess the agreement between IP-CUS and vascular sonographer performed DUS for proximal lower extremity deep vein thrombosis (PLEDVT) screening in high-risk trauma patients in ICU.

Methods

A prospective observational study was conducted at the ICU of Alfred Hospital, a major trauma center in Melbourne, Australia, between Feb and Nov 2015. All adult major trauma patients admitted with high risk for DVT were eligible for inclusion. IP-CUS was performed immediately before or after DUS for PLEDVT screening. The paired studies were repeated twice weekly until the DVT diagnosis, death or ICU discharge. Written informed consent from the patient, or person responsible, or procedural authorisation, was obtained. The individuals performing the scans were blinded to the others’ results. The agreement analysis was performed using Cohen’s Kappa statistics and intraclass correlation coefficient for repeated binary measurements.

Results

During the study period, 117 patients had 193 pairs of scans, and 45 (39%) patients had more than one pair of scans. The median age (IQR) was 47 (28–68) years with 77% males, mean (SD) injury severity score 27.5 (9.53), and a median (IQR) ICU length of stay 7 (3.2–11.6) days. There were 16 cases (13.6%) of PLEDVT with an incidence rate of 2.6 (1.6–4.2) cases per 100 patient-days in ICU. The overall agreement was 96.7% (95% CI 94.15–99.33). The Cohen’s Kappa between the IP-CUS and DUS was 0.77 (95% CI 0.59–0.95), and the intraclass correlation coefficient for repeated binary measures was 0.75 (95% CI 0.67–0.81).

Conclusions

There is a substantial agreement between IP-CUS and DUS for PLEDVT screening in trauma patients in ICU with high risk for DVT. Large multicentre studies are needed to confirm this finding.

Ultrasonography in the Critical Care Unit

Purpose of Review

This article summarizes the utility and evidence supporting the use of ultrasound exams in the intensive care unit.

Recent Findings

Point-of-care ultrasonography (POCUS) is widely used by intensivists managing critically ill patients whereby they can accurately and rapidly assess for many pathologies such as pneumothorax, pulmonary edema, hydronephrosis, hemoperitoneum, and deep vein thrombosis among others. Basic and advanced critical care echocardiography, including transesophageal echocardiography, are routinely performed to determine the etiology of hemodynamic instability in undifferentiated shock and to guide subsequent therapy. The use of POCUS in the assessment of volume status is controversial with studies demonstrating that respiratory variation of the IVC is not reliable and with analysis of aortic blood flow velocity after passive leg raising maneuvers being the most promising.

Summary

Point-of-care ultrasonography allows frontline clinicians to make real-time diagnoses and treatment decisions. This article will provide the reader with a broad overview of this important topic.

Electronic supplementary material

The online version of this article (10.1007/s11886-020-01393-z) contains supplementary material, which is available to authorized users.

A proposed lung ultrasound and phenotypic algorithm for the care of COVID-19 patients with acute respiratory failure

Pulmonary complications are the most common clinical manifestations of coronavirus disease (COVID-19). From recent clinical observation, two phenotypes have emerged: a low elastance or L-type and a high elastance or H-type. Clinical presentation, pathophysiology, pulmonary mechanics, radiological and ultrasound findings of these two phenotypes are different. Consequently, the therapeutic approach also varies between the two. We propose a management algorithm that combines the respiratory rate and oxygenation index with bedside lung ultrasound examination and monitoring that could help determine earlier the requirement for intubation and other surveillance of COVID-19 patients with respiratory failure.

Elevated risk of venous thromboembolism among post-traumatic brain injury patients requiring pharmaceutical immobilization

Traumatic brain injury (TBI) patients are known to have a high rate of venous thromboembolism (VTE), and additional neuromuscular blockade or barbiturate coma therapy has the theoretical risk of exacerbating baseline hemostasis and elevating the incidence of thromboembolic events. We conducted a single-institution retrospective review of patients surviving severe TBI, as determined by need for intracranial pressure (ICP) monitoring, who further required paralytics or barbiturate therapy to maintain ICP control. Patients were administered VTE prophylaxis as clinically appropriate. Predictors for VTE were subsequently determined with univariate and logistic multivariate regression analyses. The main cohort includes 144 patients, 34 of whom received pharmaceutical immobilization for ICP control. Mean ISS and GCS at intake were 31.9 and 5.2, respectively. Among those receiving vs not-receiving paralytics and/or barbiturate therapy, there was a statistical difference of 12/34 (35.3%) vs 18/110 (16.4%, p = 0.0280) in VTE events, at a mean time greater than two weeks from the time of trauma. Multivariate logistics regression indicated 3.2 times increased odds of developing a VTE (log odds = 1.17, p = 0.023). No pediatric patients were positive for an event (0/12 vs 7/22, p = 0.0356), and infections were only documented among those with VTE (0/22 vs 4/12, p = 0.0107). Overall, paralytics and barbiturate therapy were correlated with a higher incidence of VTE among TBI patients. Although the need for ICP control will outweigh an increase in thromboembolic risk, there is value for increased surveillance and screening during the prolonged inpatient stay of these patients.

Better With Ultrasound: Detection of DVT

Ultrasound studies to detect DVT are traditionally performed and interpreted by sonographers and radiologists, respectively, but the growth of point-of-care ultrasound is putting this powerful tool in the hands of front-line physicians. Literature from ambulatory patients in the ED suggests this tool performs well in the hands of nonconventional users, and it is now being commonly deployed to aid in the management of critically ill patients. This article presents an approach for incorporating these tools into bedside practice, including illustrative figures and narrated video presentations to demonstrate the techniques described.

Point-of-care ultrasound for deep venous thrombosis of the lower limb

The incidence and morbidity of deep venous thrombosis (DVT) and pulmonary embolus are high. Although efforts to increase screening for DVT have been recommended, this is limited by resources. Venous duplex ultrasound has replaced venography as the first-line investigation of choice for DVT, increasing availability and reducing patient exposure to radiation and intravenous contrast. Furthermore, an abbreviated ultrasound where DVT is inferred from incomplete venous compressibility has an equivalent accuracy to venous duplex, requiring less time and training enabling its widespread use by emergency, critical care and anaesthesia clinicians. In this review, the evolution and method of lower limb venous compression ultrasound is described along with evidence for its use in patients at high risk for DVT in these clinical settings.

Hospitalist-Operated Compression Ultrasonography: a Point-of-Care Ultrasound Study (HOCUS-POCUS)

BACKGROUND

Venous thromboembolism includes deep vein thrombosis (DVT) and pulmonary embolism. Compression ultrasonography is the most common way to evaluate DVT and is typically performed by sonographers and interpreted by radiologists. Yet there is evidence that ultrasound examinations can be safely and accurately performed by clinicians at the bedside.

OBJECTIVE

To measure the operating characteristics of hospital medicine providers performing point-of-care ultrasound (POCUS) for evaluation of DVT.

DESIGN

This is a prospective cohort study enrolling a convenience sample of patients. Hospital medicine providers performed POCUS for DVT and the results were compared with the corresponding formal vascular study (FVS) interpreted by radiologists.

PARTICIPANTS

Hospitalized non-ICU patients at four tertiary care hospitals for whom a DVT ultrasound was ordered.

MAIN MEASURES

The primary outcomes were the sensitivity, specificity, and predictive values of the POCUS compression ultrasound compared with a FVS. The secondary outcome was the elapsed time between order and the POCUS study compared with the time the FVS was ordered to when the formal radiology report was finalized.

KEY RESULTS

One hundred twenty-five limbs from 73 patients were scanned. The prevalence of DVT was 6.4% (8/125). The sensitivity of POCUS for DVT was 100% (95% CI 74-100%) and specificity was 95.8% (95% CI 91-98%) with a positive predictive value of 61.5% (95% CI 35-84%) and a negative predictive value of 100% (95% CI 98-100%). The median time from order to POCUS completion was 5.8 h versus 11.5 h median time from order until the radiology report was finalized (p = 0.001).

CONCLUSION

Hospital medicine providers can perform compression-only POCUS for DVT on inpatients with accuracy similar to other specialties and settings, with results available sooner than radiology. The observed prevalence of DVT was lower than expected. POCUS may be reliable in excluding DVT but further study is required to determine how to incorporate a positive POCUS DVT result into clinical practice.

Point of care ultrasound in thoracic malignancy

Ultrasonography is a safe, efficient and cost-effective mode of imaging that can assist clinicians with important treatment decisions and provide procedural guidance. Today, point of care ultrasound plays an essential role in the assessment of benign and malignant conditions of chest, both in the outpatient and inpatient setting. Small, ultra-portable, affordable units can now be carried in the coat pocket. Advanced lung cancer, metastatic diseases to the lungs or thoracic malignancies can present with pleural effusion, pulmonary edema, post-obstructive pneumonia, or ascites that can be assessed by the clinician with ultrasound. It can be used to evaluate the extent of thoracic tumors beyond the parenchyma to the parietal pleura or chest wall, assess cervical, supraclavicular lymphadenopathy prior to fine needle aspiration or to determine venous thromboembolism (VTE) associated with malignancy. Thoracic ultrasound is currently being practiced by the pulmonologists, thoracic surgeons and intensivists to provide guidance during placement of pleural catheters, chest tubes or to evaluate the pleural cavity before thoracoscopy. Point of care ultrasound can improve efficiency in procedures by decreasing complications, increasing success and reducing financial strain on the health care system.

Venous thromboembolism in the critically ill: A prospective observational study of occurrence, risk factors and outcome

BACKGROUND

The aim of the study was to explore occurrence, risk factors and outcome of venous thromboembolism (VTE) in intensive care unit (ICU) patients.

METHODS

Prospective observational study of ICU patients receiving thromboprophylaxis at Oslo University Hospital in Norway. Adult medical and surgical patients with ICU length of stay (LOS) longer than 48 hours were included. For detection of VTE, Doppler ultrasound screening of neck, upper and lower extremity veins was used, and computed tomography angiography when clinically indicated for any medical reason.

RESULTS

Among 70 included patients, 79% were males and mean age was 62 (±12.1) years. All received thromboprophylaxis with dalteparin, and 44 (63%) used graduated compression stockings. VTE was found in 19 (27%) patients; deep vein thrombosis in 15 (21%) and pulmonary embolism in 4 (6%). Among the VTEs, 11 (58%) presented within the first 48 hours after admission, two (11%) were located in the lower limbs and five (26%) were symptomatic. Risk factors for VTE in multivariable analyses were malignancy, abdominal surgery and SAPS II score <41 with an AuROC (95% CI) of 0.72 (0.58-0.85, P = 0.01). Patients with and without VTE had comparable ICU LOS (13 vs 11 days, P = 0.27) and mortality (16% vs 20%, P = 0.72).

CONCLUSION

Venous thromboembolism was observed in 27% of ICU patients receiving thromboprophylaxis. Factors associated with increased risk of VTE were malignancy, abdominal surgery and SAPS II score <41. Presence of VTE did not impact on patient outcome.

Comparison of 2-point and 3-point point-of-care ultrasound techniques for deep vein thrombosis at the emergency department: A meta-analysis

BACKGROUND

To our knowledge, so far, no studies have comprehensively examined the performance of 2-point and 3-point point-of-care compression ultrasound (POCUS) in the diagnosis of lower extremity deep vein thrombosis (DVT). The aim of this meta-analysis was to compare the performance of 2-point and 3-point POCUS techniques for the diagnosis of DVT and evaluate the false-negative rate of each POCUS method.

METHODS

A computerized search of the PubMed, EMBASE, and Cochrane library databases was performed to identify relevant original articles. Bivariate modeling and hierarchical summary receiver operating characteristic modeling were performed to compare the diagnostic performance of 2-point and 3-point POCUS. The pooled proportions of the false-negative rate for each POCUS method were assessed using a DerSimonian-Laird random-effects model. Meta-regression analyses were performed according to the patient and study characteristics.

RESULTS

Seventeen studies from 16 original articles were included (2-point, 1337 patients in 9 studies; 3-point, 1035 patients in 8 studies). Overall, 2-point POCUS had similar pooled sensitivity [0.91; 95% confidence interval (95% CI), 0.68-0.98; P = .86) and specificity (0.98; 95% CI, 0.96-0.99; P = .60) as 3-point POCUS (sensitivity, 0.90; 95% CI, 0.83-0.95 and specificity, 0.95; 95% CI, 0.83-0.99). The false-negative rates of 2-point (4.0%) and 3-point POCUS (4.1%) were almost similar. Meta-regression analysis showed that high sensitivity and specificity tended to be associated with an initial POCUS performer (including attending emergency physician > only resident) and separate POCUS training for DVT (trained > not reported), respectively.

CONCLUSION

Both 2-point and 3-point POCUS techniques showed excellent performance for the diagnosis of DVT. We recommend that POCUS-trained attending emergency physicians perform the initial 2-point POCUS to effectively and accurately diagnose DVT.

Point-of-Care Ultrasound in the Intensive Care Unit

Spreading beyond the realm of tertiary academic medical centers, point-of-care ultrasound in the intensive care unit is an important diagnostic tool. The real-time feedback garnered can lead to critical and clinically relevant changes in management and decrease potential complications. Bedside ultrasound evaluation in the intensive care setting with a small, portable equipment is well-suited for placement of central lines, lumbar puncture, thoracentesis or other bedside ICU procedures and in the evaluation of cardiac activity, pleural and abdominal cavity and the overall fluid volume. Formalized curriculums centering on point-of-care ultrasound are emerging that will enhance its applicability and relevance.

Brief report of a novel advanced practice provider-led course for ultrasound novices

BACKGROUND AND PURPOSE

Formal training for ultrasound use is essential for critical care providers. Despite a national increase in the utilization of advanced practice providers in critical care, ultrasound education is not routinely provided in their training programs. This study describes and evaluates a 1-day advanced care provider (APP)-led course designed to provide fellow APPs with the skills to obtain and evaluate basic ultrasound images.

METHODS

A 15-question pretest was administered via anonymous use of a clicker response system. Participants had didactic lectures followed by hands-on experience with live models and instructor. Posttest was administered after achievement of basic ultrasound views. Postcourse evaluations were also administered.

CONCLUSIONS

Pretest and posttest questions included identifying anatomy, pathology, quantifying cardiac function, and clinical decision making. Scores improved from 58% on the pretest to 78% on the posttest. All participants acknowledged the need for the course and their ability to transfer the course into practice.

IMPLICATIONS FOR PRACTICE

This course established that APPs can both teach and learn from their peers in a formal setting. In addition, this course demonstrated that an APP-led course with a combined hands-on and didactic approach is an effective method for critical care ultrasound skills acquisition in ultrasound-novice APPs.

Diagnostic Accuracy of Point-of-Care Ultrasound Performed by Pulmonary Critical Care Physicians for Right Ventricle Assessment in Patients With Acute Pulmonary Embolism

OBJECTIVES

Risk stratification for acute pulmonary embolism using imaging presence of right ventricular dysfunction is essential for triage; however, comprehensive transthoracic echocardiography has limited availability. We assessed the accuracy and timeliness of Pulmonary Critical Care Medicine Fellow's performance of goal-directed echocardiograms and intensivists' interpretations for evaluating right ventricular dysfunction in acute pulmonary embolism.

DESIGN

Prospective observational study and retrospective chart review.

SETTING

Four hundred fifty bed urban teaching hospital.

PATIENTS

Adult in/outpatients diagnosed with acute pulmonary embolism.

INTERVENTIONS

Pulmonary critical care fellows performed and documented their goal-directed echocardiogram as normal or abnormal for right ventricular size and function in patients with acute pulmonary embolism. Gold standard transthoracic echocardiography was performed on schedule unless the goal-directed echocardiogram showed critical findings. Attending intensivists blinded to the clinical scenario reviewed these exams at a later date.

MEASUREMENTS AND MAIN RESULTS

Two hundred eighty-seven consecutive patients were evaluated for acute PE. Pulmonary Critical Care Medicine Fellows performed 154 goal-directed echocardiograms, 110 with complete cardiology-reviewed transthoracic echocardiography within 48 hours for comparison. Pulmonary Critical Care Medicine Fellow's area under the curve for size and function was 0.83 (95% CI, 0.75-0.90) and 0.83 (95% CI, 0.75-0.90), respectively. Intensivists' 1/2 area under the curve for size and function was (1) 0.87 (95% CI, 0.82-0.94), (1) 0.87 (95% CI, 0.80-0.93) and (2) 0.88 (95% CI, 0.82-0.95), (2) 0.88 (95% CI, 0.82-0.95). Median time difference between goal-directed echocardiogram and transthoracic echocardiography was 21 hours 18 minutes.

CONCLUSIONS

This is the first study to evaluate pulmonary critical care fellows' and intensivists' use of goal-directed echocardiography in diagnosing right ventricular dysfunction in acute pulmonary embolism. Pulmonary Critical Care Medicine Fellows and intensivists made a timely and accurate assessment. Screening for right ventricular dysfunction using goal-directed echocardiography can and should be performed by pulmonary critical care physicians in patients with acute pulmonary embolism.