Chylothorax: a rare complication of tube thoracostomy

Background: Chylothorax resulting from chest tube injury to the thoracic duct is very rare and underreported. Objective: The purpose of this case report is to exemplify this rare but potentially significant complication of chest tube thoracostomy. Case Report: An 86-year-old woman presented with sepsis and a massive right pleural effusion; she developed a chylous effusion with the pleural fluid triglyceride level of 158 mg/dL 2 days after a traumatic chest tube insertion. All investigations excluded common causes of non-traumatic chylothorax. The chylothorax improved after fasting and implementation of a medium-chain triglyceride diet. Conclusion: The optimal depth of insertion of the chest tube typically ranges from 5 to 15 cm, ensuring all sideports are within the chest and the proximal port is at least 2 cm beyond the rib margin. Traumatic chylothorax secondary to chest tube insertion should be included in the differential diagnosis of patients presenting with chylothorax after a thoracostomy tube.     

In-Flight Thoracic Ultrasound Detection of Pneumothorax in Combat

Background: Ultrasonography is the only portable imaging modality available in the helicopter medical evacuation environment where physical examination is limited, auscultation is impossible, long transport times may occur, and altitude variations are frequent. Although the use of ultrasonography by aviation medical personnel has been documented, minimal literature exists on the contribution of in-flight ultrasonography to patient management. Objectives: This case demonstrates an indication for the use of in-flight ultrasonography. It shows how it can affect in-flight management and direct lifesaving intervention. Case Report: A patient with blast injury developed hemodynamic instability of unclear etiology during transport in the combat aviation environment. To our knowledge, this is the first reported case where in-flight thoracic ultrasonography augmented physical examination and diagnosed an untreated pneumothorax when auscultation was impossible. It directed the decision to perform in-flight procedural intervention with tube thoracostomy. This rapidly improved the patient's hemodynamic stability in a remote and hostile setting. Conclusion: In-flight thoracic ultrasonography is a portable imaging tool that can be used by aviation medical personnel to detect pneumothorax in environments where physical examination is limited and auscultation is impossible.     

The Diagnostic Accuracy of Ultrasonography for the Diagnosis of Rib Fractures in Patients Presenting to Emergency Department With Blunt Chest Trauma

BackgroundRib fractures are the most common complications of blunt chest trauma (BCT). Computed tomography (CT) is the modality of choice for BCT, but with several disadvantages. Ultrasonography (US) is an inexpensive, readily available, and relatively harmless imaging alternative. However, a direct comparison of the sonographic evaluation of the rib as a whole with CT as a reference has not been performed to date.ObjectiveThis study aimed to compare the diagnostic accuracy of US with CT for the detection of rib fractures in patients who presented to emergency department (ED) with BCT.MethodsWe included a convenience sample of adult patients who presented to the ED with thoracic pain after BCT in the last 24 h in this prospective, observational, diagnostic accuracy study. The diagnostic utility of US performed by an emergency physician was compared with thorax CT.ResultsThe final study population included 145 patients. The diagnostic accuracy of US was 80% with a sensitivity of 91.2% and specificity of 72.7% for the detection of any rib fracture (positive likelihood ratio 3.4 and negative likelihood ratio 0.12). If we considered each rib separately, the sensitivity of US decreased to 76.7% and specificity increased to 82.7% (81.3% accuracy).ConclusionsA negative US of the site of the highest tenderness and neighboring ribs in a patient with BCT who presented to the ED with lateralizing pain decreases the possibility of a rib fracture significantly. However, a positive US performs poorly to specify the exact location and number of the fractured ribs.     

Residency Training in Emergency Ultrasound: Fulfilling the Mandate

Although bedside ultrasound is listed in the Model of the Clinical Practice of Emergency Medicine as an integral diagnostic procedure, the manner in which the didactic, hands-on, and experiential components of emergency ultrasound are taught is not specifically prescribed by the Residency Review Committee for Emergency Medicine (RRC-EM) or any single sponsoring group. Seven professional organizations [the American Board of Emergency Medicine (ABEM), the American College of Emergency Medicine (ACEP), the Council of Emergency Medicine Residency Directors (CORD), the Emergency Medicine Residents Association (EMRA), the National Association of EMS Physicians (NAEMSP), the RRC-EM, and the Society for Academic Emergency Medicine (SAEM)] developed the Scope of Training Task Force, with the goal of identifying emerging areas of clinical importance to the specialty of emergency medicine, including emergency department (ED) ultrasound. The Task Force then identified a group of recognized authorities to thoughtfully address the issue of ED ultrasound training. This report represents a consensus of these identified experts on how emergency ultrasound training should be incorporated into emergency medicine residency programs.     

Potential Errors in the Diagnosis of Pericardial Effusion on Trauma Ultrasound for Penetrating Injuries

OBJECTIVE: To evaluate ultrasound error in patients presenting with penetrating injury with a potential for pericardial effusion. METHODS: Residents and faculty from an emergency medicine training program at Level 1 trauma center with an active ultrasound program were asked to view digitized video clips of subxiphoid cardiac examinations in patients with chest trauma. Participants were asked to fill out a standardized questionnaire on each video clip asking whether a pericardial effusion was present. Other questions included size of effusion and presence of tamponade. The study also asked participants to rate their confidence in their impressions. Data were analyzed using interquartile ranges and confidence levels. RESULTS: All participants had difficulty distinguishing between epicardial fat pads and true pericardial effusions. The overall sensitivity was 73% and specificity was 44%. Confidence shown by participants in their answers increased with level of training or experience, regardless of whether they were correct or incorrect. Additional views were frequently requested to help decide whether an effusion was present. CONCLUSIONS: A serious potential exists for misdiagnosing epicardial fat pads as pericardial effusion in critically ill trauma patients. Emergency physicians need to be aware of this and should consider one of two suggested alternative methods to improve the accuracy of diagnosis.     

Sensitivity of Bedside Ultrasound and Supine Anteroposterior Chest Radiographs for the Identification of Pneumothorax After Blunt Trauma

Objectives: Supine anteroposterior (AP) chest radiographs in patients with blunt trauma have poor sensitivity for the identification of pneumothorax. Ultrasound (US) has been proposed as an alternative screening test for pneumothorax in this population. The authors conducted an evidence‐based review of the medical literature to compare sensitivity of bedside US and AP chest radiographs in identifying pneumothorax after blunt trauma. Methods: MEDLINE and EMBASE databases were searched for trials from 1965 through June 2009 using a search strategy derived from the following PICO formulation of our clinical question: patients included adult (18 + years) emergency department (ED) patients in whom pneumothorax was suspected after blunt trauma. The intervention was thoracic ultrasonography for the detection of pneumothorax. The comparator was the supine AP chest radiograph during the initial evaluation of the patient. The outcome was the diagnostic performance of US in identifying the presence of pneumothorax in the study population. The criterion standard for the presence or absence of pneumothorax was computed tomography (CT) of the chest or a rush of air during thoracostomy tube placement (in unstable patients). Prospective, observational trials of emergency physician (EP)‐performed thoracic US were included. Trials in which the exams were performed by radiologists or surgeons, or trials that investigated patients suffering penetrating trauma or with spontaneous or iatrogenic pneumothoraces, were excluded. The methodologic quality of the studies was assessed. Qualitative methods were used to summarize the study results. Data analysis consisted of test performance (sensitivity and specificity, with 95% confidence intervals [CIs]) of thoracic US and supine AP chest radiography. Results: Four prospective observational studies were identified, with a total of 606 subjects who met the inclusion and exclusion criteria. The sensitivity and specificity of US for the detection of pneumothorax ranged from 86% to 98% and 97% to 100%, respectively. The sensitivity of supine AP chest radiographs for the detection of pneumothorax ranged from 28% to 75%. The specificity of supine AP chest radiographs was 100% in all included studies. Conclusions: This evidence‐based review suggests that bedside thoracic US is a more sensitive screening test than supine AP chest radiography for the detection of pneumothorax in adult patients with blunt chest trauma. ACADEMIC EMERGENCY MEDICINE 2010; 17:11–17 © 2010 by the Society for Academic Emergency Medicine     

A Prospective Comparison of Supine Chest Radiography and Bedside Ultrasound for the Diagnosis of Traumatic Pneumothorax

Background: Supine anteroposterior (AP) chest radiography may not detect the presence of a small or medium pneumothorax (PTX) in trauma patients. Objectives: To compare the sensitivity and specificity of bedside ultrasound (US) in the emergency department (ED) with supine portable AP chest radiography for the detection of PTX in trauma patients, and to determine whether US can grade the size of the PTX. Methods: This was a prospective, single‐blinded study with convenience sampling, based on researcher availability, of blunt trauma patients at a Level 1 trauma center with an annual census of 75,000 patients. Enrollment criteria were adult trauma patients receiving computed tomography (CT) of the abdomen and pelvis (which includes lung windows at the authors' institution). Patients in whom the examination could not be completed were excluded. During the initial evaluation, attending emergency physicians performed bedside trauma US examinations to determine the presence of a sliding lung sign to rule out PTX. Portable, supine AP chest radiographs were evaluated by an attending trauma physician, blinded to the results of the thoracic US. The CT results (used as the criterion standard), or air release on chest tube placement, were compared with US and chest radiograph findings. Sensitivities and specificities with 95% confidence intervals (95% CIs) were calculated for US and AP chest radiography for the detection of PTX, and Spearman's rank correlation was used to evaluate for the ability of US to predict the size of the PTX on CT. Results: A total of 176 patients were enrolled in the study over an eight‐month period. Twelve patients had a chest tube placed prior to CT. Pneumothorax was detected in 53 (30%) patients by US, and 40 (23%) by chest radiography. There were 53 (30%) true positives by CT or on chest tube placement. The sensitivity for chest radiography was 75.5% (95% CI = 61.7% to 86.2%) and the specificity was 100% (95% CI = 97.1% to 100%). The sensitivity for US was 98.1% (95% CI = 89.9% to 99.9%) and the specificity was 99.2% (95% CI = 95.6% to 99.9%). The positive likelihood ratio for a PTX was 121. Spearman's rank correlation showed at ρ of 0.82. Conclusions: With CT as the criterion standard, US is more sensitive than flat AP chest radiography in the diagnosis of traumatic PTX. Furthermore, US allowed sonologists to differentiate between small, medium, and large PTXs with good agreement with CT results.     

Confirmation of Endotracheal Tube Placement after Intubation Using the Ultrasound Sliding Lung Sign

Objectives: To evaluate the performance of the ultrasound (US) sliding lung sign as a predictor of endotracheal tube (ETT) placement. Many other tools and examination findings have been used to confirm ETT placement; erroneous placement of the ETT has even been confirmed by US. Methods: This was a laboratory study using fresh, recently dead cadavers. Cadavers were obtained at a medical school anatomy laboratory on the basis of availability during a four‐month period. Subjects who died from significant trauma or after thoracic surgery were excluded. A numerical randomization tool was used to direct where the tube would be placed on intubation. Laryngoscopy was performed, and the ETT was placed in the esophagus, in the trachea, or in the right main stem (RMS) bronchus. Placement was confirmed by direct laryngoscopic visualization of ETT passage through vocal cords or with fiber optic visualization, as needed. US images of the sliding lung sign, sliding of visceral and parietal pleura past each other, were taken on both sides of the chest at the mid axillary line during ventilation with an ambu bag. Two board‐certified emergency physicians with hospital credentialing in emergency US used a 4‐2 MHz micro‐convex transducer on a Sonosite 180 Plus for imaging. The sonologists were blinded to the location of the endotracheal tube and imaged and recorded their results individually. A positive sliding lung sign was taken to signify lung expansion with ventilation in a hemithorax. Endotracheal versus esophageal ETT placement, as well as tracheal versus RMS, was determined on the basis of sliding lung findings on both sides of the chest. Interpreter agreement, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and likelihood ratios (LHR) were calculated for tracheal (including RMS) versus esophageal, as well as main trachea versus RMS intubation. Results: Nine cadavers yielded 68 intubations. For esophageal versus tracheal (including RMS) intubation, sonologist 1 (S1) had a sensitivity of 95.4% (95% CI = 84.2% to 99.4%), a specificity of 100% (95% CI = 86.3% to 100%), an NPV of 92.6% (95% CI = 75.7% to 99.1%), and a PPV of 100% (95% CI = 91.4% to 100%) with an LHR of 0.05 (95% CI = 0.01 to 0.2) for a negative test. Sonologist 2 (S2) had a sensitivity of 100% (95% CI = 91.8% to 100%), a specificity of 100% (95% CI = 86.3% to 100%), an NPV of 100% (95% CI = 86.3% to 100%), and a PPV of 100% (95% CI = 91.8% to 100%); agreement was 97% (κ= 0.94; 95% CI = 0.7 to 1.2). In RMS versus tracheal, S1 had a sensitivity of 69.2% (95% CI = 48.2% to 85.7%), a specificity of 93.3% (95% CI = 68.1% to 99.8%), a PPV of 94.7% (95% CI = 73.9% to 99.9%), and an NPV of 63.6% (95% CI = 40.7% to 82.8%) with an LHR for a positive test of 10.4 (95% CI = 2.2 to 59.1) and of 0.4 (95% CI = 0.2 to 0.6) for negative test. S2 had a sensitivity of 78.6% (95% CI = 59.1% to 91.7%), a specificity of 100% (95% CI = 78.2% to 100%), a PPV of 100% (95% CI = 84.6% to 100%), NPV of 71.4% (95% CI = 47.8% to 88.7%), with an LHR for a negative test of 0.2 (95% CI = 0.1 to 0.4); agreement was 85.9% (κ= 0.6; 95% CI = 0.4 to 0.9). Conclusions: These results show that US imaging of the sliding lung sign in a cadaver model is an accurate method for confirmation of ETT placement. Further, the technique may have some utility in differentiating RMS bronchus from main tracheal intubations.     

Use of Point-of-Care Ultrasound for the Diagnosis of Ovarian Hyperstimulation Syndrome

BackgroundOvarian hyperstimulation syndrome (OHSS) occurs when ovaries are overstimulated and enlarged due to fertility treatments resulting in a shift of serum from the intravascular space to the third space, mainly the abdominal cavity. It is the most serious complication of ovarian hyperstimulation for assisted reproduction.Case ReportWe present the case of a 40-year-old woman who presented with abdominal bloating and nausea 2 weeks after undergoing in vitro fertilization (IVF); she was diagnosed by an outside radiology ultrasound as having a ruptured ovarian cyst. A point-of-care emergency ultrasound performed by the emergency physician made the diagnosis of ovarian hyperstimulation syndrome. This led to more expedient management and obstetrical consultation.Why Should an Emergency Physician Be Aware of This?Abdominal bloating and nausea are common presenting complaints in pregnant women. OHSS is a rare but potentially fatal complication of IVF. Recognition and early diagnosis by the emergency physician can lead to appropriate intervention and consultation.     

Hybrid Simulation Combining a High Fidelity Scenario with a Pelvic Ultrasound Task Trainer Enhances the Training and Evaluation of Endovaginal Ultrasound Skills

Objectives: In this study, an endovaginal ultrasound (US) task trainer was combined with a high‐fidelity US mannequin to create a hybrid simulation model. In a scenario depicting a patient with ectopic pregnancy and hemorrhagic shock, this model was compared with a standard high‐fidelity simulation during training sessions with emergency medicine (EM) residents. The authors hypothesized that use of the hybrid model would increase both the residents’ self‐reported educational experience and the faculty’s self‐reported ability to evaluate the residents’ skills. Methods: A total of 45 EM residents at two institutions were randomized into two groups. Each group was assigned to one of two formats involving an ectopic pregnancy scenario. One format incorporated the new hybrid model, in which residents had to manipulate an endovaginal US probe in a task trainer; the other used the standard high‐fidelity simulation mannequin together with static photo images. After finishing the scenario, residents self‐rated their overall learning experience and how well the scenario evaluated their ability to interpret endovaginal US images. Faculty members reviewed video recordings of the other institution’s residents and rated their own ability to evaluate residents’ skills in interpreting endovaginal US images and diagnosing and managing the case scenario. Visual analog scales (VAS) were used for the self‐ratings. Results: Compared to the residents assigned to the standard simulation scenario, residents assigned to the hybrid model reported an increase in their overall educational experience (Δ VAS = 10, 95% confidence interval [CI] = 4 to 18) and felt the hybrid model was a better measure of their ability to interpret endovaginal US images (Δ VAS = 17, 95% CI = 7 to 28). Faculty members found the hybrid model to be better than the standard simulation for evaluating residents’ skills in interpreting endovaginal US images (Δ VAS = 13, 95% CI = 6 to 20) and diagnosing and managing the case (Δ VAS = 10, 95% CI = 2 to 18). Time to reach a diagnosis was similar in both groups (p = 0.053). Conclusions: Use of a hybrid simulation model combining a high‐fidelity simulation with an endovaginal US task trainer improved residents’ educational experience and improved faculty’s ability to evaluate residents’ endovaginal US and clinical skills. This novel hybrid tool should be considered for future education and evaluation of EM residents.     

B超引导下胸椎旁神经阻滞治疗急性带状疱疹肋间神经痛的研究

目的:探讨B超引导下胸椎旁神经阻滞在治疗急性带状疱疹肋间神经痛中的临床疗效。方法:80例胸背部急性带状疱疹伴肋间神经痛患者随机分为两组,每组各40例。A组(对照组)予常规抗病毒及按需口服镇痛药物治疗,B组(试验组)同时接受在B超引导下选择性胸椎旁神经阻滞治疗。观察治疗后7、14及30天两组患者疼痛视觉模拟评分(VAS)、辅助镇痛药用量、不良反应及后遗神经痛(PHN)发生率。结果:治疗后各观察时间点两组VAS评分均较治疗前降低(P0.009),组间比较差异显著,B组明显低于A组(P0.05)。辅助镇痛药物用量、PHN发生率B组亦显著低于A组(P0.05)。两组均无明显不良反应发生。结论:B超引导下胸椎旁神经阻滞联合抗毒治疗急性带状疱疹肋间神经痛安全有效,明显优于单纯药物治疗,并可减少后遗神经痛的发生率,值得临床推广应用。