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

Incidence of Deep Vein Thrombosis and Venous Thromboembolism following TKA in Rheumatoid Arthritis versus Osteoarthritis: A Meta-Analysis

This meta-analysis was designed to compare the incidence of deep vein thrombosis (DVT) and venous thromboembolism (VTE) following total knee arthroplasty (TKA) in patients with rheumatoid arthritis (RA) and osteoarthritis (OA). All studies directly comparing the post-TKA incidence of DVT and/or VTE in patients with RA and OA were included. For all comparisons, odds ratios and 95% confidence intervals (CI) were calculated for binary outcomes. Six studies were included in the meta-analysis. The pooled data showed that the combined rates of asymptomatic and symptomatic DVT did not differ significantly in the RA and OA groups (1065/222,714 [0.5%] vs. 35,983/6,959,157 [0.5%]; OR 0.77, 95% CI: 0.57 to 1.02; P = 0.07). The combined rates of asymptomatic and symptomatic DVT and pulmonary embolism (PE) after TKA were significantly lower in the RA than in the OA group (1831/225,406 [0.8%] vs. 63,953/7,018,721 [0.9%]; OR 0.76, 95% CI: 0.62 to 0.93; P = 0.008). Conclusiviely, the DVT rates after primary TKA were similar in RA and OA patients. In contrast, the incidence of VTE (DVT plus PE) after primary TKA was lower in RA than in OA patients, despite patients with RA being at theoretically higher risk of thrombi due to chronic inflammation.

Predicting Central Venous Pressure by Measuring Femoral Venous Diameter Using Ultrasonography

Objectives

The objective of this exploratory study was to find out the correlation of femoral vein diameter (FVD) to central venous pressure (CVP) measurements and to derive a prediction equation to help ascertain the fluid volume status in a critical patient.

Patients and methods

This was a single-centered prospective cohort study designed and conducted by the critical care department of Shifa International hospital in Islamabad, Pakistan. Patients were enrolled from the medical and surgical intensive care units. The inclusion criteria consisted of patients > 18 years of age, and an intrathoracic central venous catheterization (CVC) in place for producing CVP waveform through the transducer. Patients having contraindications to CVP placement and those unable to lie supine were excluded from the study. Critical Care fellows with sufficient training in performing venous ultrasonography measured the FVD. They were blinded to the CVP values of the same patients.

Results

The study included 108 patients. Among these 70/108 (64.8%) were males. Mean age was 53.85 (SD=16.74). The CVP and femoral vein diameter were measured in all patients. Mean CVP was 9.89 cmH2O (SD=3.46) and mean femoral vein diameter was 0.92 cm (SD=0.27). Multiple regression was used to generate a prediction model. FVD, age and sex of the patient were used as predictor variables to predict CVP diameter. The model was statistically significant with a p-value of < 0.000 and an F-value of 104.806. R-squared value for this model came out to be 0.744, thus the model was able to explain about 74.4% of the variance in the values observed for CVP. When controlled for age and sex, FVD was found highly correlated with CVP diameter with a p-value of < 0.000. A regression equation was derived that can be used to generate predicted values of CVP in millimeters of mercury with an R-square of 0.745 if FVD in centimeters is provided; CVP (cmH2O) = -0.039 + 10.718* FVD.

Conclusions

FVD was found highly correlated to CVP measurements and it suggests an alternate non-invasive method of ascertaining the volume status in the critically ill.

Measurement of Femoral Vein Diameter by Ultrasound to Estimate Central Venous Pressure

RATIONALE

Central venous pressure (CVP) can be estimated by ultrasound of the inferior vena cava (IVC), but imaging the IVC is sometimes challenging. The femoral vein is easily imaged by ultrasound and might therefore provide an alternate target for estimating CVP.

OBJECTIVES

To assess femoral vein diameter (FVD) measured by ultrasound imaging for estimating CVP.

METHODS

We prospectively measured CVP and FVD in 97 patients. Receiver operating characteristic curves were used to assess the ability of FVD to predict specific CVP values: less than 10 mm Hg, less than 8 mm Hg (low CVP), and greater than 12 mm Hg (high CVP). Interobserver variability of FVD measurement was assessed in 20 patients.

MEASUREMENTS AND MAIN RESULTS

There was moderate correlation between FVD and CVP (r = 0.66, P < 0.001). FVD less than or equal to 0.8 cm was the best predictor of CVP < 10 mm Hg, with an area under the curve (AUC) of 0.894 and a 95% confidence interval (CI) of 0.82 to 0.97. FVD less than or equal to 0.7 cm performed best for predicting low CVP (AUC = 0.97; 95% CI, 0.94-0.99) and FVD greater than or equal to 1.0 cm for high CVP (AUC = 0.80; 95% CI, 0.72-0.89). However, FVD greater than or equal to 1.2 cm had the greatest specificity (94%) for high CVP. Interobserver variability in FVD measurements was 8.3 ± 7.2%.

CONCLUSIONS

The results of this exploratory study suggest that the accuracy of FVD measured by ultrasound imaging for estimating CVP is comparable to that which has been reported for ultrasound measurement of IVC diameter. FVD may provide an alternative approach when the IVC is difficult to image. Additional studies on other cohorts of patients are warranted to validate our proposed FVD cutoff values for predicting low and high CVP.

Effectiveness of a Critical Care Ultrasonography Course

BACKGROUND

Widespread use of critical care ultrasonography (CCUS) for the management of patients in the ICU requires an effective training program. The effectiveness of national and regional CCUS training courses is not known. This study describes a national-level, simulation-based, 3-day CCUS training program and evaluates its effectiveness.

METHODS

Five consecutive CCUS courses, with a total of 363 people, were studied. The 3-day CCUS training program consisted of didactic lectures, ultrasonography interpretation sessions, and hands-on modules with live models. Thoracic, vascular, and abdominal ultrasonography were taught in addition to goal-directed echocardiography. Learners rotated between hands-on training and interpretation sessions. The teacher-to-learner ratio was 1:3 during hands-on training. Interpretation sessions were composed of interactive small groups that reviewed normal and abnormal ultrasonography images. Learners completed a video-based examination before and after completion of the courses. Hands-on image acquisition skills were tested at the completion of the course.

RESULTS

Average scores on the pretest and posttest were 57% and 90%, respectively (P < .001). The average score on the hands-on test was 86%. Learners aged 20 to 39 years compared with learners ≥ 40 years old scored better on the pretest (64% vs 51%; P < 0.001), posttest (91% vs 88%; P < .010), and hands-on test (90% vs 82%; P < .001).

CONCLUSIONS

Learners demonstrated a significant improvement in written test scores that assessed cognitive and image interpretation abilities. In addition, they demonstrated acquisition of practical skills as evidenced by high scores during hands-on testing. Further studies are needed to determine if a simulation-based CCUS course will translate into effective clinical practice and to measure the durability of training. This 3-day course is an effective method to train large groups of critical care clinicians in the skills requisite for CCUS (image acquisition and image interpretation).

A Whole-Body Approach to Point of Care Ultrasound

Ultrasonography is an essential imaging modality in the ICU used to diagnose and guide the treatment of cardiopulmonary failure. Critical care ultrasonography requires that all image acquisition, image interpretation, and clinical applications of ultrasonography are personally performed by the critical care clinician at the point of care and that the information obtained is combined with the history, physical, and laboratory information. Point-of-care ultrasonography is often compartmentalized such that the clinician will focus on one body system while performing the critical care ultrasonography examination. We suggest a change from this compartmentalized approach to a systematic whole-body ultrasonography approach. The standard whole-body ultrasonography examination includes thoracic, cardiac, limited abdominal, and an evaluation for DVT. Other elements of ultrasonography are used when clinically indicated. Each of these elements is reviewed in this article and are accompanied by a link to pertinent cases from the Ultrasound Corner section of CHEST.

Ultrasonography in the emergency department

Point-of-care ultrasonography (POCUS) is a useful imaging technique for the emergency medicine (EM) physician. Because of its growing use in EM, this article will summarize the historical development, the scope of practice, and some evidence supporting the current applications of POCUS in the adult emergency department. Bedside ultrasonography in the emergency department shares clinical applications with critical care ultrasonography, including goal-directed echocardiography, echocardiography during cardiac arrest, thoracic ultrasonography, evaluation for deep vein thrombosis and pulmonary embolism, screening abdominal ultrasonography, ultrasonography in trauma, and guidance of procedures with ultrasonography. Some applications of POCUS unique to the emergency department include abdominal ultrasonography of the right upper quadrant and appendix, obstetric, testicular, soft tissue/musculoskeletal, and ocular ultrasonography. Ultrasonography has become an integral part of EM over the past two decades, and it is an important skill which positively influences patient outcomes.

Critical Care Basic Ultrasound Learning Goals for American Anesthesiology Critical Care Trainees: Recommendations from an Expert Group

OBJECTIVE

In this review, we define learning goals and recommend competencies concerning focused basic critical care ultrasound (CCUS) for critical care specialists in training.

DESIGN

The narrative review is, and the recommendations contained herein are, sponsored by the Society of Critical Care Anesthesiologists. Our recommendations are based on a structured literature review by an expert panel of anesthesiology intensivists and cardiologists with formal training in ultrasound. Published descriptions of learning and training routines from anesthesia-critical care and other specialties were identified and considered. Sections were written by groups with special expertise, with dissent included in the text.

RESULTS

Learning goals and objectives were identified for achieving competence in the use of CCUS at a specialist level (critical care fellowship training) for diagnosis and monitoring of vital organ dysfunction in the critical care environment. The ultrasound examination was divided into vascular, abdominal, thoracic, and cardiac components. For each component, learning goals and specific skills were presented. Suggestions for teaching and training methods were described.

DISCUSSION

Immediate bedside availability of ultrasound resources can dramatically improve the ability of critical care physicians to care for critically ill patients. Anesthesia--critical care medicine training should have definitive expectations and performance standards for basic CCUS interpretation by anesthesiology--critical care specialists. The learning goals in this review reflect current trends in the multispecialty critical care environment where ultrasound-based diagnostic strategies are already frequently applied. These competencies should be formally taught as part of an established anesthesiology-critical care medicine graduate medical education programs.

Diagnostic accuracy of point-of-care ultrasound for catheter-related thrombosis in children

BACKGROUND

Compared with consultative US performed by the radiology department, point-of-care US performed by non-radiology physicians can accurately diagnose deep venous thrombosis in adults.

OBJECTIVE

In preparation for a multicenter randomized controlled trial, we determined the accuracy of point-of-care US in diagnosing central venous catheter-related thrombosis in critically ill children.

MATERIALS AND METHODS

Children <18 years old with a central venous catheter who were admitted to the intensive care unit were enrolled. Consultative and point-of-care compression ultrasounds with Doppler were done on the vein where the catheter was inserted within 24 h after insertion. Repeat US was obtained within 24 h of removal of the catheter. All images were centrally, blindly and independently adjudicated for thrombosis by a team of pediatric radiologists. Chance-corrected agreement between readings was calculated.

RESULTS

From 84 children, 152 pairs of consultative and point-of-care ultrasounds were analyzed. A total of 38 (25.0%) consultative and 17 (11.2%) point-of-care ultrasounds were positive for thrombosis. The chance-corrected agreement between consultative and point-of-care ultrasounds was 0.17 (standard error: 0.07; P = 0.008). With consultative US as a reference, the sensitivity of point-of-care US was 28.1% (95% confidence interval: 13.7%-46.7%) with a specificity of 91.8% (95% confidence interval: 84.4%-96.4%). A catheter in the subclavian vein was associated with discordant readings (adjusted odds ratio: 4.00; 95% confidence interval: 1.45-13.94).

CONCLUSION

Point-of-care US, when performed by non-radiology physicians and centrally adjudicated by pediatric radiologists in the setting of a multicenter randomized controlled trial, may not accurately diagnose catheter-related thrombosis in critically ill children.

Effects of a Foot Pump on the Incidence of Deep Vein Thrombosis After Total Knee Arthroplasty in Patients Given Edoxaban: A Randomized Controlled Study

We conducted a randomized clinical trial to compare the effectiveness of the A-V Impulse System foot pump for reducing the incidence of deep-vein thrombosis (DVT) after total knee arthroplasty (TKA) in patients under edoxaban thromboprophylaxis. Patients undergoing primary TKA at our institution between September 2013 and March 2015 were enrolled after obtaining informed consent. The patients were randomized to use the foot pump (n = 58) and not to use the foot pump (n = 62). Both groups were given prophylactic edoxaban. Primary outcomes were any DVT as detected by bilateral ultrasonography up to postoperative day 10 (POD10) and pulmonary embolism (PE) up to POD28. The safety outcomes were bleeding and death of any cause up to POD28. Plasma D-dimer levels were measured before TKA and on POD10 after TKA. Immunoglobulin G (IgG)-class anti-PF4/heparin antibodies were measured using an IgG-specific enzyme-linked immunosorbent assay. The incidences of any DVT up to POD28 were 31.0% and 17.7% in patients with or without the foot pump, respectively. The incidences of major bleeding up to POD28 were 5.1% and 4.8% in patients with or without the foot pump, respectively. Foot pump use did not significantly reduce the incidence of DVTs in patients undergoing TKA under edoxaban thromboprophylaxis. Although seroconversion of anti-PF4/heparin antibodies was confirmed in one-fourth of patients, the seroconversion rates did not differ between patients with (20.7%) or without (25.8%) foot pump use. This study shows that the A-V Impulse system foot pump did not affect the incidence of DVT under edoxaban thromboprophylaxis in patients undergoing TKA. Seroconversion of anti-PF4/heparin antibodies was detected in a significant number of patients who underwent TKA under antithrombotic prophylaxis using edoxaban.

Venous thromboembolism in the ICU: main characteristics, diagnosis and thromboprophylaxis

Venous thromboembolism (VTE), including pulmonary embolism (PE) and deep venous thrombosis (DVT), is a common and severe complication of critical illness. Although well documented in the general population, the prevalence of PE is less known in the ICU, where it is more difficult to diagnose and to treat. Critically ill patients are at high risk of VTE because they combine both general risk factors together with specific ICU risk factors of VTE, like sedation, immobilization, vasopressors or central venous catheter. Compression ultrasonography and computed tomography (CT) scan are the primary tools to diagnose DVT and PE, respectively, in the ICU. CT scan, as well as transesophageal echography, are good for evaluating the severity of PE. Thromboprophylaxis is needed in all ICU patients, mainly with low molecular weight heparin, such as fragmine, which can be used even in cases of non-severe renal failure. Mechanical thromboprophylaxis has to be used if anticoagulation is not possible. Nevertheless, VTE can occur despite well-conducted thromboprophylaxis.

Risk of venous thromboembolism after total knee arthroplasty in patients with rheumatoid arthritis

OBJECTIVE

To compare the incidence of venous thromboembolism (VTE) following total knee arthroplasty (TKA) between patients with rheumatoid arthritis (RA) and those with osteoarthritis (OA).

METHODS

The subjects were composed of 1084 Japanese patients with OA and 204 with RA. Primary effectiveness outcomes were any deep vein thrombosis (DVT) as detected by bilateral ultrasonography up to postoperative Day 10 (POD10) and pulmonary embolism (PE) up to POD28. The main safety outcomes were bleeding and death from any cause up to POD28. Plasma D-dimer levels were measured before and at POD10 after TKA.

RESULTS

The study cohort was composed of 1288 patients from 34 hospitals. There was no death up to POD28. PE occurred in 2 patients with OA and in no patients with RA. The incidence of primary effectiveness outcome was 24.3% and 24.0% in patients with OA and RA, respectively. The incidence of major bleeding up to POD28 was 1.3% and 0.5% in patients with OA and RA, respectively. No differences in the incidence of VTE (symptomatic/asymptomatic DVT plus PE) or bleeding were noted between patients with RA and OA. D-dimer levels on POD10 were significantly higher in patients with OA compared with those with RA. Also, D-dimer levels on POD10 were significantly lower in patients receiving fondaparinux than in patients without pharmacological prophylaxis.

CONCLUSION

Despite some differences in demographic data, patients with RA and OA have equivalent risks of VTE and bleeding following TKA.

Point-of-Care Ultrasound for a Deep Venous Thrombosis

Patients presenting to the emergency department with lower extremity symptoms suggestive of venous thromboembolic disease require a diagnostic evaluation. Although contrast venography was the diagnostic standard, this has largely been replaced by duplex ultrasound as the first-line imaging modality. This review presents a summary of the literature on the evolution and performance of B-mode point-of-care compression ultrasound as an alternative to duplex ultrasound evaluation. The 2-point compression and 2-region compression techniques are described. The limitations of point-of-care ultrasound of the lower extremity as a diagnostic modality for this disease entity, the role of a D-dimer assay in the emergency department evaluation and future directions for this diagnostic modality are discussed.

Resident performed two-point compression ultrasound is inadequate for diagnosis of deep vein thrombosis in the critically III

Doppler ultrasonography is a standard in diagnosis of deep vein thrombosis (DVT) but is often delayed. Clinician-performed focused vascular sonography (FVS) has proven to accurately diagnose DVT in the ambulatory and emergency room settings. Whether trained medical residents can perform quality FVS in the critically ill is unknown. Medical residents were trained in a 2-hour module in FVS assessing for complete compressibility of common femoral and popliteal veins. Residents imaged consecutive medical ICU and intermediate care patients awaiting comprehensive, sonographer-performed and radiologist-interpreted examinations. Sensitivity, specificity, positive and negative predictive values of the focused examination were calculated against the comprehensive study. Fleiss Kappa (κ), the degree of agreement between resident and radiologist, was calculated. Time savings was measured. Nineteen residents performed 143 studies on 75 patients. Twelve patients had above-the-knee DVTs, a prevalence of 16 %. All 6 common femoral and 7 of 9 popliteal vein DVTs were identified. None of 6 isolated superficial femoral DVTs were identified. Sensitivity for above-the-knee DVT was 63 %, specificity 97 %. Sensitivity for common femoral and popliteal DVT was 86 %, specificity 97 %. Residents showed substantial agreement with radiologists for diagnosis of DVT (κ = 0.70, SE 0.114, p < 0.001).Time from order of a formal ultrasound to a radiologist's read averaged 14.7 h. The two-point compression ultrasound method demonstrated insufficient sensitivity in a cohort of critically ill medical patients due to a high-incidence of superficial femoral DVT. However, residents demonstrated substantial agreement with radiologists for the diagnosis of clinically relevant DVT after a 2-hour course. FVS should include the superficial femoral vein and is associated with a significant time savings.

The Saudi clinical practice guideline for the diagnosis of the first deep venous thrombosis of the lower extremity

The diagnosis of deep venous thrombosis (DVT) may be challenging due to the inaccuracy of clinical assessment and diversity of diagnostic tests. On one hand, missed diagnosis may result in life-threatening conditions. On the other hand, unnecessary treatment may lead to serious complications. As a result of an initiative of the Ministry of Health of the Kingdom of Saudi Arabia (KSA), an expert panel led by the Saudi Association for Venous Thrombo-Embolism (SAVTE; a subsidiary of the Saudi Thoracic Society) with the methodological support of the McMaster University Working Group, produced this clinical practice guideline to assist healthcare providers in evidence-based clinical decision-making for the diagnosis of a suspected first DVT of the lower extremity. Twenty-four questions were identified and corresponding recommendations were made following the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. These recommendations included assessing the clinical probability of DVT using Wells criteria before requesting any test and undergoing a sequential diagnostic evaluation, mainly using highly sensitive D-dimer by enzyme-linked immunosorbent assay (ELISA) and compression ultrasound. Although venography is the reference standard test for the diagnosis of DVT, its use was not recommended.

Utility of ultrasound in the ICU

PURPOSE OF REVIEW

Use of ultrasound in the acute care setting has become more common in recent years. However, it still remains underutilized in the perioperative management of critical patients. In this review, we aim to increase the awareness of ultrasound as an important diagnostic modality that can be used in the perioperative period to improve patient care. Our main focus will be in describing the diagnostic uses of ultrasound to identify cardiac, pulmonary, airway and vascular diseases commonly encountered in acute care settings.

RECENT FINDINGS

We find that ultrasound can be used in a quick fashion to assess a haemodynamically unstable patient. Protocols are available to use ultrasound as a part of cardiopulmonary resuscitation. Ultrasound can help in deciding fluid vs. pressor treatment by evaluating the inferior vena cava and other cardiac structures.Lung ultrasound can not only help in diagnosing pneumothoracies and effusions but also look at lung recruitment and diaphragmatic movement, hence can aid in deciding extubation strategies. This modality can be utilized for confirmation of endotracheal tube.Recent interest in axillary vein cannulation with ultrasound guidance has gained some momentum.

SUMMARY

This article covers the recent developments and literature available on point of care ultrasound and its utilization in the perioperative period. We have not covered some other important uses of ultrasound such as abdominal examination looking at the aorta and other abdominal organs. This was beyond the scope of this article.

Bedside ultrasonography for the intensivist

Critical care ultrasonography is a bedside technique performed by the frontline clinician at the point of care. Point-of-care ultrasonography is conceptually related to physical examination. The intensivist uses visual assessment, auscultation, and palpation on an ongoing basis to monitor the patient. Ultrasonography adds to traditional physical examination by allowing the intensivist to visualize the anatomy and function of the body in real time. Initial, repeated, and goal-directed ultrasonography is an extension of the physical examination that allows the intensivist to establish a diagnosis and monitor the condition of the patient on a regular basis.

18F-fluorodeoxyglucose positron emission tomography/computed tomography enables the detection of recurrent same-site deep vein thrombosis by illuminating recently formed, neutrophil-rich thrombus

BACKGROUND

Accurate detection of recurrent same-site deep vein thrombosis (DVT) is a challenging clinical problem. Because DVT formation and resolution are associated with a preponderance of inflammatory cells, we investigated whether noninvasive (18)F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) imaging could identify inflamed, recently formed thrombi and thereby improve the diagnosis of recurrent DVT.

METHODS AND RESULTS

We established a stasis-induced DVT model in murine jugular veins and also a novel model of recurrent stasis DVT in mice. C57BL/6 mice (n=35) underwent ligation of the jugular vein to induce stasis DVT. FDG-PET/computed tomography (CT) was performed at DVT time points of day 2, 4, 7, 14, or 2+16 (same-site recurrent DVT at day 2 overlying a primary DVT at day 16). Antibody-based neutrophil depletion was performed in a subset of mice before DVT formation and FDG-PET/CT. In a clinical study, 38 patients with lower extremity DVT or controls undergoing FDG-PET were analyzed. Stasis DVT demonstrated that the highest FDG signal occurred at day 2, followed by a time-dependent decrease (P<0.05). Histological analyses demonstrated that thrombus neutrophils (P<0.01), but not macrophages, correlated with thrombus PET signal intensity. Neutrophil depletion decreased FDG signals in day 2 DVT in comparison with controls (P=0.03). Recurrent DVT demonstrated significantly higher FDG uptake than organized day 14 DVT (P=0.03). The FDG DVT signal in patients also exhibited a time-dependent decrease (P<0.01).

CONCLUSIONS

Noninvasive FDG-PET/CT identifies neutrophil-dependent thrombus inflammation in murine DVT, and demonstrates a time-dependent signal decrease in both murine and clinical DVT. FDG-PET/CT may offer a molecular imaging strategy to accurately diagnose recurrent DVT.

Venous thromboembolism after total joint arthroplasty: results from a Japanese multicenter cohort study

Introduction

Real-world evidence of the effectiveness of pharmacological thromboprophylaxis for venous thromboembolism (VTE) is limited. Our objective was to assess the effectiveness and safety of thromboprophylactic regimens in Japanese patients undergoing joint replacement in a real-world setting.

Method

Overall, 1,294 patients (1,073 females and 221 males) who underwent total knee arthroplasty (TKA) and 868 patients (740 females and 128 males) who underwent total hip arthroplasty (THA) in 34 Japanese national hospital organization (NHO) hospitals were enrolled. The primary efficacy outcome was the incidence of deep vein thrombosis (DVT) detected by mandatory bilateral ultrasonography up to post-operative day (POD) 10 and pulmonary embolism (PE) up to POD28. The main safety outcomes were bleeding (major or minor) and death from any cause up to POD28.

Results

Patients undergoing TKA (n = 1,294) received fondaparinux (n = 360), enoxaparin (n = 223), unfractionated heparin (n = 72), anti-platelet agents (n = 45), or no medication (n = 594). Patients undergoing THA (n = 868) received fondaparinux (n = 261), enoxaparin (n = 148), unfractionated heparin (n = 32), anti-platelet agents (n = 44), or no medication (n = 383). The incidence rates of sonographically diagnosed DVTs up to POD10 were 24.3% in patients undergoing TKA and 12.6% in patients undergoing THA, and the incidence rates of major bleeding up to POD28 were 1.2% and 2.3%, respectively. Neither fatal bleeding nor fatal pulmonary embolism occurred. Significant risk factors for postoperative VTE identified by multivariate analysis included gender (female) in both TKA and THA groups and use of a foot pump in the TKA group. Only prophylaxis with fondaparinux reduced the occurrence of VTE significantly in both groups. Propensity score matching analysis (fondaparinux versus enoxaparin) showed that the incidence of DVT was lower (relative risk 0.70, 95% confidence interval (CI) 0.58 to 0.85, P = 0.002 in TKA and relative risk 0.73, 95% CI 0.53 to 0.99, P = 0.134 in THA) but that the incidence of major bleeding was higher in the fondaparinux than in the enoxaparin group (3.4% versus 0.5%, P = 0.062 in TKA and 4.9% versus 0%, P = 0.022 in THA).

Conclusions

These findings indicate that prophylaxis with fondaparinux, not enoxaparin, reduces the risk of DVT but increases bleeding tendency in patients undergoing TKA and THA.

Trial registration

University Hospital Medical Information Network Clinical Trials Registry: UMIN000001366. Registered 11 September 2008.

Ultrasound assessment of pulmonary embolism in patients receiving CT pulmonary angiography

BACKGROUND

CT pulmonary angiography (CTPA) is considered the gold standard for the diagnosis of pulmonary embolism (PE) and is frequently performed in patients with cardiopulmonary complaints. However, indiscriminate use of CTPA results in significant exposure to ionizing radiation and contrast. We studied the accuracy of a bedside ultrasound protocol to predict the need for CTPA.

METHODS

This was an observational study performed by pulmonary/critical care physicians trained in critical care ultrasonography. Screening ultrasonography was performed when a CTPA was ordered to rule out PE. The ultrasound examination consisted of a limited ECG, thoracic ultrasonography, and lower extremity deep venous compression study. We predicted that CTPA would not be needed if either DVT was found or clear evidence of an alternative diagnosis was established. CTPA parenchymal and pleural findings, and, when available, formal DVT and ECG results, were compared with our screening ultrasound findings.

RESULTS

Of 96 subjects who underwent CTPA, 12 subjects (12.5%) were positive for PE. All 96 subjects had an ultrasound study; two subjects (2.1%) were positive for lower extremity DVT, and 54 subjects (56.2%) had an alternative diagnosis suggested by ultrasonography, such as alveolar consolidation consistent with pneumonia or pulmonary edema, which correlated with CTPA findings. In no patient did the CTPA add an additional diagnosis over the screening ultrasound study.

CONCLUSIONS

We conclude that ultrasound examination indicated that CTPA was not needed in 56 of 96 patients (58.3%). A screening, point-of-care ultrasonography protocol may predict the need for CTPA. Furthermore, an alternative diagnosis can be established that correlates with CTPA. This study needs further verification, but it offers a possible approach to reduce the cost and radiation exposure that is associated with CTPA.

Lemierre syndrome: not so forgotten!

Lemierre syndrome is a rare and life-threatening illness. Often referred to as "the forgotten disease," its incidence is reported to be as low as 1 in a million. The microorganism responsible for Lemierre syndrome is typically Fusobacterium necrophorum. The bacterium starts in the pharynx and peritonsillar tissue, then disseminates through lymphatic vessels. Severe sepsis rapidly develops, as does the hallmark of this syndrome: septic thrombophlebitis of the internal jugular vein. This report describes a case of Lemierre syndrome in a previously healthy 26-year-old man with life-threatening internal jugular vein thrombophlebitis following 2 weeks of an indolent course of pharyngitis. The patient's initial presentation and extensive travel history as an Army veteran were particularly challenging aspects in establishing his diagnosis. The diagnosis of Lemierre syndrome is frequently delayed. Routine use of bedside ultrasonography may aid in rapid diagnosis of the disease.

Ultrasound-based imaging in neurocritical care patients: a review of clinical applications

OBJECTIVE

To analyze the diagnostic, monitoring, and procedural applications of ultrasound (US) imaging in neurocritical care (NCC) patients.

METHOD

US imaging has been extensively validated in various subset of critically ill patients, but not specifically in the NCC population. We reviewed the clinical applications of US imaging for heart, vascular, brain, and lung evaluation and for possible procedural uses in NCC patients. Major neurosurgical books, journals, testimonials, authors' personal experience, and scientific databases were analyzed.

RESULTS

Cardiac US imaging provides accurate information at NCC arrival to stratify risk factors, including presence of atrial septal defect/patent formen ovale, abnormal ventricular function, or pericardial effusion, and to monitor cardiac anatomy and function during the NCC stay for guiding goal-directed therapy. Vascular US in NCC patients has three especially relevant indications: to screen anatomy and flow in extracranial supra-aortic arteries, to diagnose deep vein thrombosis, and to optimize the safety of central venous catheterization. Brain US has important clinical applications in the NCC, including transcranial Doppler and emerging techniques for cerebral blood flow evaluation with contrast-enhanced US imaging. Lung US, as demonstrated in other intensive care unit patients, provides accurate diagnosis of anatomical and functional abnormalities and enables diagnosis of pleural effusion, pneumothorax, lung consolidation, pulmonary abscess and interstitial-alveolar syndrome, and lung recruitment/derecruitment. US imaging can effectively guide percutaneous tracheostomy.

CONCLUSION

In conclusion, US imaging is an important diagnostic tool that provides real-time information at the bedside to stratify risk, monitor for complications, and guide invasive procedures in NCC patients.

[Prevention of venous thromboembolic disease in the critical patient: an assessment of clinical practice in the Community of Madrid]

OBJECTIVE

To analyze measures referred to venous thromboembolic prophylaxis in critically ill patients.

DESIGN

An epidemiological, cross-sectional (prevalence cut), multicenter study was performed using an electronic survey. Comparison of results with quality indexes of the Spanish Society of Intensive Care Medicine, the American College of Chest Physician guidelines and international studies.

SETTING

Intensive Care Units (ICUs) in the Community of Madrid (Spain).

PATIENTS

All patients admitted to the ICU on the day of the survey.

VARIABLES OF INTEREST

General aspects of venous thromboembolic prophylaxis and protocols used (risk stratification and ultrasound screening). A descriptive analysis was performed, continuous data being expressed as the mean or median, and categorical data as percentages.

RESULTS

A total of 234 patients in 18 ICUs were included. Eighteen percent (42/234) received no prophylaxis, and 55% had no contraindication to pharmacological prophylaxis. Of the 192 patients receiving prophylaxis, 84% received pharmacological prophylaxis, 14% mechanical prophylaxis and 2% combined prophylaxis. Low molecular weight heparin was the only pharmacological prophylaxis used, with a majority use of enoxaparin (17 of 18 ICUs). In patients with mechanical prophylaxis (31/192), antiembolic stockings were the most commonly used option (58%). Pharmacological prophylaxis contraindications were reported in 20% of the patients (46/234), the most frequent cause being thrombocytopenia (28% of the cases). Fifty percent of the ICUs used no specific venous thromboembolic prophylaxis protocol.

CONCLUSIONS

Pharmacological prophylaxis with low molecular weight heparin was the most frequently used venous thromboembolic prophylactic measure. In patients with contraindications to pharmacological prophylaxis, mechanical measures were little used. The use of combined prophylaxis was anecdotal. Many of our ICUs lack specific prophylaxis protocols.

Pulmonary embolism

Pulmonary embolism (PE) is responsible for approximately 100,000 to 200,000 deaths in the United States each year. With a diverse range of clinical presentations from asymptomatic to death, diagnosing PE can be challenging. Various resources are available, such as clinical scoring systems, laboratory data, and imaging studies which help guide clinicians in their work-up of PE. Prompt recognition and treatment are essential for minimizing the mortality and morbidity associated with PE. Advances in recognition and treatment have also enabled treatment of some patients in the home setting and limited the amount of time spent in the hospital. This article will review the risk factors, pathophysiology, clinical presentation, evaluation, and treatment of PE.

Core review: physician-performed ultrasound: the time has come for routine use in acute care medicine

The use of ultrasound in the acute care specialties of anesthesiology, intensive care, emergency medicine, and surgery has evolved from discrete, office-based echocardiographic examinations to the real-time or point-of-care clinical assessment and interventions. "Goal-focused" transthoracic echocardiography is a limited scope (as compared with comprehensive examination) echocardiographic examination, performed by the treating clinician in acute care medical practice, and is aimed at addressing specific clinical concerns. In the future, the practice of surface ultrasound will be integrated into the everyday clinical practice as ultrasound-assisted examination and ultrasound-guided procedures. This evolution should start at the medical student level and be reinforced throughout specialist training. The key to making ultrasound available to every physician is through education programs designed to facilitate uptake, rather than to prevent access to this technology and education by specialist craft groups. There is evidence that diagnosis is improved with ultrasound examination, yet data showing change in management and improvement in patient outcome are few and an important area for future research.

An ultrasound study of cerebral venous drainage after internal jugular vein catheterization

Objectives. It has been advocated that internal jugular vein (IJV) cannulation in patients at risk for intracranial hypertension could impair cerebral venous return. Aim of this study was to demonstrate that ultrasound-guided IJV cannulation in elective neurosurgical patients is safe and does not impair cerebral venous return. Methods. IJV cross-sectional diameter and flow were measured using two-dimensional ultrasound and Doppler function bilaterally before and after IJV cannulation with the head supine and elevated at 30°. Results. Fifty patients with intracranial lesions at risk for intracranial hypertension were enrolled in this observational prospective study. IJV diameters before and after ultrasound-guided cannulation were not statistically different during supine or head-up position and the absolute variation of the venous flow revealed an average reduction of the venous flow after cannulation without a significant reduction of the venous flow rate after cannulation. Conclusions. Ultrasound-guided IJV cannulation in neurosurgical patients at risk for intracranial hypertension does not impair significantly jugular venous flow and indirectly cerebral venous return.

Advanced technologies in trauma critical care management

Care of critically injured patients has evolved over the 50 years since Shoemaker established one of the first trauma units at Cook County Hospital in 1962. Modern trauma intensive care units offer a high nurse-to-patient ratio, physicians and midlevel providers who manage the patients, and technologically advanced monitors and therapeutic devices designed to optimize the care of patients. This article describes advances that have transformed trauma critical care, including bedside ultrasonography, novel patient monitoring techniques, extracorporeal support, and negative pressure dressings. It also discusses how to evaluate the safety and efficacy of future advances in trauma critical care.

ICU 2020: five interventions to revolutionize quality of care in the ICU

Intensive care units (ICUs) are an essential and unique component of modern medicine. The number of critically ill individuals, complexity of illness, and cost of care continue to increase with time. In order to meet future demands, maintain quality, and minimize medical errors, intensivists will need to look beyond traditional medical practice, seeking lessons on quality assurance from industry and aviation. Intensivists will be challenged to keep pace with rapidly advancing information technology and its diverse roles in ICU care delivery. Modern ICU quality improvement initiatives include ensuring evidence-based best practice, participation in multicenter ICU collaborations, employing state-of-the-art information technology, providing point-of-care diagnostic testing, and efficient organization of ICU care delivery. This article demonstrates that each of these initiatives has the potential to revolutionize the quality of future ICU care in the United States.