Critical Ultrasound Journal最新文献

Introduction: This study evaluates the agreement between emergency physician (EP) assessment of diastolic dysfunction (DD) by a simplified approach using average peak mitral excursion velocity (e'_A) and an independent cardiologist's diagnosis of DD by estimating left atrial (LA) pressure using American Society of Echocardiography (ASE) guidelines.

Methods: This was a secondary analysis of 48 limited bedside echocardiograms (LBE) performed as a part of a research study of patients presenting to the Emergency Department (ED) with elevated blood pressure but without decompensated heart failure. EPs diagnosed DD based on e'_A < 9 cm/s alone. A blinded board-certified cardiologist reviewed LBEs to estimate LA filling pressures following ASE guidelines. An unweighted kappa measure was calculated to determine agreement between EP and cardiologist.

Results: Six LBEs were deemed indeterminate by the cardiologist and excluded from the analysis. Agreement was reached in 41 out of 48 cases (85.4%). The unweighted kappa coefficient was 0.74 (95% CI 0.57-0.92). EPs identified 18 out of 20 LBEs diagnosed with diastolic dysfunction by the cardiologist.

Conclusion: There is a good agreement between (e'_A) by EP and cardiologist interpretation of LBEs. Future studies should investigate this simplified approach as a one-step method of screening for LV diastolic dysfunction in the ED.

Background: Recognition of the difficult airway is a critical element of emergency practice. Mallampati score and body mass index (BMI) are not always predictive and they may be unavailable in critically ill patients. Ultrasonography provides high-resolution images that are rapidly obtainable, mobile, and non-invasive. Studies have shown correlation of ultrasound measurements with difficult laryngoscopy; however, none have been performed in the Emergency Department (ED) using a consistent scanning protocol.

Objectives: This study seeks to determine the feasibility of ultrasound measurements of the upper airway performed in the ED by emergency physicians, the inter-rater reliability of such measurements, and their relationship with Mallampati score and BMI.

Methods: A convenience sample of volunteer ED patients and healthy volunteers with no known airway issues, aged > 18 years, had images taken of their airway using a standardized ultrasound scanning protocol by two EM ultrasound fellowship trained physicians. Measurements consisted of tongue base, tongue base-to-skin, epiglottic width and thickness, and pre-epiglottic space. Mean and standard deviation (SD) were used to summarize measurements. Inter-rater reliability was assessed by intraclass correlation coefficients (ICCs). Analysis of variance with linear contrasts was used to compare measurements with Mallampati scores and linear regression with BMI.

Results: Of 39 participants, 50% were female, 50% white, 42% black, with median age 32.5 years (range 19-90), and BMI 26.0 (range 19-47). Mean ± SD for each measurement (mm) was as follows: tongue base (44.6 ± 5.1), tongue base-to-skin (60.9 ± 5.3), epiglottic width (15.0 ± 2.8) and thickness (2.0 ± 0.37), and pre-epiglottic space (11.4 ± 2.4). ICCs ranged from 0.76 to 0.88 for all measurements except epiglottis thickness (ICC = 0.57). Tongue base and tongue base-to-skin thickness were found to increase with increasing Mallampati score (p = .04, .01), whereas only tongue-to-skin thickness was loosely correlated with BMI (r = .38).

Conclusions: A standardized ultrasound scanning protocol demonstrates that the airway can be measured by emergency sonologists with good inter-operator reliability in all but epiglottic thickness. The measurements correlate with Mallampati score but not with BMI. Future investigation might focus on ultrasound evaluation of the airway in patients receiving airway management to determine whether ultrasound can predict challenging or abnormal airway anatomy prior to laryngoscopy.

Background: Early detection of vasospasm is crucial to prevent significant delayed ischemic neurological deficit post subarachnoid hemorrhage. The standard methods of detection, including cerebral angiogram and computed tomography are invasive and not safe to be repeated, as is very often indicated clinically. Transient hyperemic response test has been previously used to predict autoregulation failure in traumatic brain injury and subarachnoid hemorrhage.

Aims: We investigate the usability of transient hyperemic response test as a predictor of clinical vasospasm in a cohort of patients with aneurismal subarachnoid hemorrhage.

Methods: A retrospective review of all THRT examinations done between January 2011 and July 2012 conducted at Montreal Neurological Institute and Hospital and the Montreal General Hospital. Patients diagnosed with aSAH in which the THRT was performed within the first 24-48 h of admission were included in the study. Two-dimensional transcranial Doppler images were obtained and velocities were recorded. A positive response was one in which the velocity was increased by more than 9% of the baseline systolic velocity, indicating an intact cerebral autoregulation. Lindegaard ratio > 3 is considered abnormal and in the context of elevated systolic velocity of the MCA, is highly suggestive of DIND.

Results: Fifteen patients met the inclusion criteria. A total of 6 patients developed clinical and radiological vasospasm. Out of these 6 patients, 5 (83%) had an abnormal THRT in the initial TCD assessment (p = 0.0406). We found that abnormal transient hyperemic response test readings are predictive of subsequent vasospasm development.

Conclusions: The results of this small retrospective study support the notion that transient hyperemic response test has predictive value in vasospasm development and may prove useful in patient monitoring and successful clinical management.

Background: Management of congestive heart failure (CHF) is dependent on clinical assessments of volume status, which are subjective and imprecise. Point-of-care ultrasound (POCUS) is useful in the diagnosis of CHF, but how POCUS findings correlate with therapy remains unknown. This study aimed to determine whether the changes in clinical evaluation of CHF with treatment are mirrored with changes in the number of B lines on lung ultrasound (LUS) and inferior vena cava (IVC) size. In this prospective observational study, investigators performed serial clinical and ultrasound assessments within 24 h of admission (T1), day 1 in hospital (T2) and within 24 h of discharge (T3). Clinical assessments included an evaluation of the jugular venous distension (JVD), hepatojugular reflux (HJR), pulmonary rales and a clinical congestion score was calculated. Ultrasound assessment included the IVC size and collapsibility, and the number of B lines in an 8-point scan.

Results: Fifty consecutive patients were recruited with a mean age of 71.2 years (SD 12.7). Mean clinical congestion score on admission was 5.6 (SD 1.4) and declined significantly over time to 1.3 (0.91), as did the JVP, HJR and pulmonary rales. No significant changes were found in the IVC size between T1 [1.9 (0.65)] and T3 [2.0 (0.50)] or in the IVC collapsibility index [T1 0.3 (0.19) versus T3 0.25 (0.16)]. The mean number of B lines decreased from 11 (6.1) at T1 to 8.3 (5.5) at T3, although this decrease did not reach statistical significance. Spearman correlation between JVP and HJR versus IVC collapsibility and total B lines did not yield significant results.

Conclusions: Clinical exam findings correlate over time during the management of CHF, whereas LUS and IVC results did not. The number of B lines did decrease with therapy, but did not reach statistical significance likely because the sampled population was small and had only mild heart failure. Further studies are warranted to further explore the use of lung ultrasound in this patient population.

Right heart thrombus in transit is an increasingly recognized medical emergency with very high mortality rate. Echocardiography helps to establish the diagnosis and can differentiate between right heart thrombi that result from atrial fibrillation and those originating from deep venous thrombosis. We present two cases of right heart thrombus in transit diagnosed with echocardiography that were managed with different approaches.

Background: The aim of this study is to assess the accuracy of a Fast Doppler protocol for the examination of an injured lower limb, namely 2-Point Fast Doppler (2PFD), in order to rapidly triage arterial lesions after penetrating trauma.

Methods: The presence of flow and the aspects of the Doppler waveform of the dorsalis pedis artery (DPA) and posterior tibial artery (PTA) of the injured lower limb (2PFD) were evaluated immediately before the execution of a standardized Color Duplex Doppler (SD) evaluation in 149 limbs of 140 patients with gunshot penetrating injuries. We considered 2PFD normal exams as the ones with triphasic patterns in both the DPA and PTA, and 2PFD pathologic exams as the ones with absent, biphasic, or monophasic flow patterns in the DPA and/or PTA. 2PFD data were then analyzed to assess accuracy variables, using SD results as matching test reference. According to the trauma center standard protocols, SD positive cases underwent also angiography and surgical exploration, whose findings were used to further match the 2PFD specificity.

Results: The 2PFD protocol showed a sensitivity of 100%, and a specificity of 100% compared with the SD, in the diagnostic workup of arterial injuries of the lower limbs after penetrating trauma. Furthermore, all the pathologic cases that resulted in all true positives (TP), compared with SD, were confirmed as TP also when matched with the angiography evaluation results.

Conclusions: The 2PFD protocol can rapidly identify arterial flow and differentiate between normal and pathologic spectral Doppler analyses in distal arteries. The presence of the normal triphasic flows in DPA and PTA is as sensitive as the standardized Color Doppler Duplex assessment of the entire limb in ruling out arterial lesions in lower-limb penetrating trauma. The absence of flow or the presence of a biphasic or monophasic pathologic flow in DPA and PTA is pathologic and should be always followed by further investigation. 2PFD is faster and easier to perform compared with the SD approach. It could become a new first-line screening technique, both in pre-hospital and hospital critical scenarios, particularly in contexts where advanced diagnostic performance is limited by time concerns or scarce resources.

Background: Ultrasound-guided peripheral intravenous access may present an alternative to central or intraosseous access in patients with difficult peripheral veins. Using venepuncture of a phantom model as a proxy, we investigated whether novice ultrasound users should adopt a cross-sectional or longitudinal approach when learning to access peripheral veins under ultrasound guidance. This result would inform the development of a structured training method for this procedure.

Methods: We conducted a randomised controlled trial of 30 medical students. Subjects received 35 min of training, then attempted to aspirate 1 ml of synthetic blood from a deep vein in a training model under ultrasound guidance. Subjects attempted both the cross-sectional and longitudinal approaches. Group 1 used cross-sectional first, followed by longitudinal. Group 2 used longitudinal first, then cross-sectional. We measured the time from first puncture of the model's skin to aspiration of fluid, and the number of attempts required. Subjects also reported difficulty ratings for each approach. Paired sample t-tests were used for statistical analysis.

Results: The mean number of attempts was 1.13 using the cross-sectional approach, compared with 1.30 using the longitudinal approach (p = 0.17). Mean time to aspiration of fluid was 45.1 s using the cross-sectional approach and 52.8 s using the longitudinal approach (p = 0.43). The mean difficulty score out of 10 was 3.97 for the cross-sectional approach and 3.93 for the longitudinal approach (p = 0.95).

Conclusions: We found no significant difference in effectiveness between the cross-sectional and longitudinal approaches to ultrasound-guided venepuncture when performed on a model. We believe that both approaches should be included when teaching ultrasound-guided peripheral vascular access. To confirm which approach would be best in clinical practice, we advocate future testing of both approaches on patients.

Background: The quantification of B-lines at lung ultrasonography is a valid tool to estimate the extravascular lung water (EVLW) in patients after major cardiac surgery. However, there is still uncertainty about the correlation between B-lines and EVLW in a general population of critically ill.

Aim: To evaluate a simplified lung ultrasonographic assessment as a tool to estimate the EVLW in critically ill patients admitted to a polyvalent intensive care unit (ICU).

Methods: Nineteen consecutive critically ill patients requiring mechanical ventilation and hemodynamic monitoring were enrolled. Lung ultrasonography and the thermodilution methodology (PiCCO system) were performed by two independent operators. The positive scan at lung ultrasound was defined by visualization of at least 3 B-lines. We then compared the number of chest areas positive for B-lines with the EVLW index obtained by the invasive procedure.

Results: A significant correlation was found between the number of lung quadrants positive for B-lines and EVLW indexed using both actual body weight (rho = 0.612 p = 0.0053) and predicted body weight (rho = 0.493 p = 0.032). Presence of more than 3 positive lung quadrants showed a good performance in identifying an EVLW index value >10 ml/kg of actual body weight(area under the ROC 0.894; 95% CI 0.668-0.987 p < 0.0001). Presence of of more than 4 positive lung quadrants indentified an EVLW index value >10 ml/kg of predicted body weight (area under the ROC 0.8; 95% CI 0.556-0.945 p = 0.0048).

Conclusion: A simplified lung ultrasound approach can by used as a reliable noninvasive bedside tool to predict EVLW in emergency and critically ill patients.