Severe right ventricular contusion mimicking cardiac tamponade: the value of transesophageal echocardiography in blunt chest trauma

Biocompatible propulsion for biomedical micro/nano robotics

Micro/Nano robots have shown enormous potential for diverse biomedical applications, such as targeted delivery, in vivo biosensing, minimally invasive surgery and cell manipulation through extending their area of operation to various previously inaccessible locations. The motion of these small-scale robots can be either self-propelled or remotely controlled by some external power sources. However, in order to use them for biomedical applications, optimization of biocompatible propulsion and precise controllability are highly desirable. In this article, the recent progress about the biocompatible propulsion (e.g. self-propulsion, external stimuli based propulsion and bio-hybrid propulsion) techniques for these micro/nano robotic devices are summarized along with their applications, with a special focus on the advantages and disadvantages of different propulsion techniques. The current challenges and future perspectives of these small-scale devices are discussed in the final section.

Role of Transesophageal Echocardiography in Blunt Chest Trauma

Patients who suffer blunt chest trauma are at risk for injury to the heart, and the thoracic aorta and its branch vessels. Unrecognized injury to the heart or aorta may lead to life threatening complications. Therefore, the physician caring for the trauma patient must be able to accurately and rapidly diagnose cardiac and thoracic aortic injury. Transesophageal echocardiography is an ideal tool to diagnose cardiac and aortic injury in the patient with blunt chest trauma because it provides high quality images of the heart and thoracic aorta and can safely and rapidly be performed in the emergency department, operating suite or intensive care unit. To utilize transesophageal echocardiography most effectively, the echocardiographer must be familiar with the indications, limitations, and piffalls of transesophageal echocardiography in patients with blunt chesttrauma. This review describes the role of transesophageal echocardiography in evaluating the patient with blunt chest trauma for cardiac, thoracic aortic, and mediastinal injury.

[Emergency management of thoracic trauma]

Thoracic injuries are a major cause of mortality during the "golden hour" of trauma. Many patients with chest trauma die after reaching the hospital. Less than 10% of all blunt thoracic injuries require a thoracotomy, and many potentially life-threatening conditions can be relieved by simple procedures, such as chest tube insertion.Thus, many cases of traumatic deaths due to chest injury may be prevented by prompt diagnosis and a standardized therapeutic approach in the emergency room. A high index of suspicion for lethal injury patterns, based on the mechanism of trauma and the clinical presentation, is a crucial prerequisite for an adequate initial assessment and management of patients with chest trauma. The worldwide implementation of standardized diagnostic and therapeutic guidelines, such as the "Advanced Trauma Life Support" (ATLS) protocol, has led to a significant reduction of early deaths attributed to thoracic injuries.

[Diagnosis and immediate therapeutic management of chest trauma. A systematic review of the literature]

OBJECTIVE

Injuries to the chest contribute significantly to the morbidity and mortality in multiple injured patients. This systematic review focuses on evidence based initial diagnostics and emergency room management of chest trauma.

METHODS

Clinical trials was systematically collected (Medline, Cochrane and hand searches) and classified into evidence levels (1 to 5 according to the Oxford system).

RESULTS

There are only a few studies that document the impact of injury mechanism and clinical examination of the patient. There is a positive correlation between crash severity or lateral impact with injury severity. Auscultation was found to be very sensitive in the detection of pneumothorax. Helical CT of the chest is most important in the initial work-up. Aortography is only indicated in selected cases. Whether tube thoracostomy is necessary in patients with occult pneumotharaces is still a matter of discussion. Indications for endotracheal intubation are poorly investigated and predominantly based on expert opinion.

CONCLUSION

Numerous comparative studies (LE 2) dealing with emergency diagnostics and therapy of chest trauma are available, however only a few randomized studies do exist. Based on the available data a rational therapy of chest trauma is possible.

Ultrasound and other imaging technologies in the intensive care unit

As technology advances, more imaging and procedures are performed at the bedside on critically ill patients in ICUs, thereby eliminating the risks of transporting patients. These imaging techniques can serve as diagnostic and therapeutic tools in treating the acute and chronic consequences of injured, critically ill patients. One area of growth is ultrasonography. Critical care applications of ultrasonography are expanding, and the learning curve of surgeons and intensivists performing some of these studies is improving. Ultrasonography can supplement physical examination and provide useful "real-time" information on nearly every body cavity. Other imaging technology is also available in a portable form, enabling imaging directly at the bedside. Images are now becoming readily and easily available with the advancement of teleradiology. Some of the imaging modalities are still in development, and their clinical effectiveness is being studied. In the future, more uses of these various imaging technologies may become evident and cost-effective.

The role of ultrasound in patients with possible penetrating cardiac wounds: a prospective multicenter study

BACKGROUND

Ultrasound is quickly becoming part of the trauma surgeon's practice, but its role in the patient with a penetrating truncal injury is not well defined. The purpose of this study was to evaluate the accuracy of emergency ultrasound as it was introduced into five Level I trauma centers for the diagnosis of acute hemopericardium.

METHODS

Surgeons or cardiologists (four centers) and technicians (one center) performed pericardial ultrasound examinations on patients with penetrating truncal wounds. By protocol, patients with positive examinations underwent immediate operation. Vital signs, base deficit, time from examination to operation, operative findings, treatment, and outcome were recorded.

RESULTS

Pericardial ultrasound examinations were performed in 261 patients. There were 225 (86.2%) true-negative, 29 (11.1%) true-positive, 0 false-negative, and 7 (2.7%) false-positive examinations, resulting in sensitivity of 100%, specificity of 96.9%, and accuracy of 97.3%. The mean time from ultrasound to operation was 12.1+/-5 minutes.

CONCLUSION

Ultrasound should be the initial modality for the evaluation of patients with penetrating precordial wounds because it is accurate and rapid.

Evaluation of the patient with blunt chest trauma: an evidence based approach

The patient who has sustained blunt trauma to the chest can present a diagnostic challenge to the emergency physician. There are several diagnostic modalities available for treating life-threatening injuries to these patients. The authors review published studies to support the use of these tests in diagnosing injuries from blunt thoracic trauma. The article focuses chiefly on two current areas of controversy, the diagnosis of blunt aortic and blunt myocardial injury. Finally, the authors make recommendations for the use of various tests based on the available evidence.

Surgeon-performed ultrasound for the assessment of truncal injuries: lessons learned from 1540 patients

OBJECTIVE

To determine the accuracy of the Focused Assessment for the Sonographic examination of the Trauma patient (FAST) when performed by trauma team members during a 3-year period, and to determine the clinical conditions in which the FAST is most accurate in the assessment of injured patients.

SUMMARY BACKGROUND DATA

The FAST is a rapid test that sequentially surveys the pericardial region for hemopericardium and then the right and left upper quadrants and pelvis for hemoperitoneum in patients with potential truncal injuries. The clinical conditions in which the FAST is most accurate in the assessment of injured patients have yet to be determined.

METHODS

FAST examinations were performed on patients with precordial or transthoracic wounds or blunt abdominal trauma. Patients with a positive ultrasound (US) examination for hemopericardium underwent immediate surgery, whereas those with a positive US for hemoperitoneum underwent a computed tomography scan (if they were hemodynamically stable) or immediate celiotomy (if they were hemodynamically unstable- blood pressure < or = 90 mmHg).

RESULTS

FAST examinations were performed in 1540 patients (1227 with blunt injuries, 313 with penetrating injuries). There were 1440 true-negative results, 80 true-positive results, 16 false-negative results, and 4 false-positive results; the sensitivity was 83.3%, the specificity 99.7%. US was most sensitive and specific for the evaluation of patients with precordial or transthoracic wounds (sensitivity 100%, specificity 99.3%) and hypotensive patients with blunt abdominal trauma (sensitivity 100%, specificity 100%).

CONCLUSIONS

US should be the initial diagnostic modality for the evaluation of patients with precordial wounds and blunt truncal injuries because it is rapid and accurate. Because of the high sensitivity and specificity of US in the evaluation of patients with precordial wounds and hypotensive patients with blunt torso trauma, immediate surgical intervention is justified when those patients have a positive US examination.

The surgeon's use of transesophageal echocardiography

Transesophageal echocardiography has become an instrumental diagnostic modality for the accurate evaluation of cardiac and aortic anatomy and function. Multiplanar technology has facilitated improved visualization of structures and enhanced TEE over TTE in many situations. Care of the trauma patient and critically ill patient is improved with the appropriate and timely performance of TEE. Education, certification, credentialing, and determination of competency are areas that need to be addressed continually in the future.

Chest trauma: the role of transesophageal echocardiography

Aortic and cardiac injury is commonly seen with severe chest trauma and contributes to the morbidity and mortality of automobile accidents. Transesophageal echocardiography is emerging as an important diagnostic tool for the evaluation of cardiovascular injury in the setting of acute chest trauma, and anesthesiologists should be familiar with the echocardiographic features of these traumatic lesions.

Transesophageal echocardiography in the evaluation of cardiothoracic trauma

TEE has been used in the past 13 years to examine the heart and thoracic aorta, and recently the clinical utility of TEE has greatly expanded to include its use in a variety of thoracic trauma injuries. We retrospectively reviewed the use of TEE in our institution from June 1994 to June 1995. Sixteen patients underwent TEE for a variety of indications, including traumatic aortic dissection, penetrating wounds to the precordium, retrieval of a foreign body, valvular trauma, and postoperative evaluation of cardiac repair. TEE affected patient treatment decisions in all of these cases. As a diagnostic modality and as a guide to specific therapy, TEE was safe, expedient, accurate, and highly valuable in the evaluation of patients with trauma to the heart or great vessels.

The role of surgeon-performed ultrasound in patients with possible cardiac wounds

OBJECTIVE

The authors evaluate surgeon-performed ultrasound in determining the need for operation in patients with possible cardiac wounds.

BACKGROUND DATA

Ultrasound quickly is becoming part of the surgeon's diagnostic armamentarium; however, its role for the patient with penetrating injury is less well-defined. Although accurate for the detection of hemopericardium, the lack of immediate availability of the cardiologist to perform the test may delay the diagnosis, adversely affecting patient outcome. To be an effective diagnostic test in trauma centers, ultrasound must be immediately available in the resuscitation area and performed and interpreted by surgeons.

METHODS

Surgeons performed pericardial ultrasound examinations on patients with penetrating truncal wounds but no immediate indication for operation. The subcostal view detected hemopericardium, and patients with positive examinations underwent immediate operation by the same surgeon. Vital signs, base deficit, time from examination to operation, operative findings, treatment, and outcome were recorded.

RESULTS

During 13 months, 247 patients had surgeon-performed ultrasound. There were 236 true-negative and 10 true-positive results, and no false-negative or false-positive results; however, the pericardial region could not be visualized in one patient. Sensitivity, specificity, and accuracy were 100%; mean examination time was 0.8 minute (246 patients). Of the ten true-positive examinations, three were hypotensive. The mean time (8 patients) from ultrasound to operation was 12.1 minutes; all survived. Operative findings (site of cardiac wounds) were: left ventricle (4), right ventricle (3), right atrium (2), right atrium/superior vena cava (1), and right atrium/inferior vena cava (1).

CONCLUSIONS

Surgeon-performed ultrasound is a rapid and accurate technique for diagnosing hemopericardium. Delay times from admission to operating room are minimized when the surgeon performs the ultrasound examination.

Echocardiography in the evaluation of thoracic trauma

Echocardiography has become a useful diagnostic modality in the evaluation of cardiovascular injury after thoracic trauma. Valuable information about cardiac wall motion, valvular function, pericardial effusions, and ventricular volume status can be obtained without significant risk. More recent application for the diagnosis of traumatic aortic disruption provides a safer, easier, less expensive, and more accurate method for detecting these injuries. Cardiac evaluation with TTE is unsuccessful in approximately 20% of examinations and is unable to provide the image resolution of the more invasive transesophageal approach.

Three cases of blunt chest trauma caused by constant compression mechanisms

Three patients (survivors) with isolated blunt chest traumas caused by constant compression mechanisms with known forces are reported on. The low velocity but high compression forces of the accidents, the effect on ventilation and oxygenation, specific early management and follow-up, clinical signs, and underlying complications of these patients are described and discussed.