Ultrasound-guided vascular access in critical illness.

Over the past two decades, ultrasound (US) has become widely accepted to guide safe and accurate insertion of vascular devices in critically ill patients. We emphasize central venous catheter insertion, given its broad application in critically ill patients, but also review the use of US for accessing peripheral veins, arteries, the medullary canal, and vessels for institution of extracorporeal life support. To ensure procedural safety and high cannulation success rates we recommend using a systematic protocolized approach for US-guided vascular access in elective clinical situations. A standardized approach minimizes variability in clinical practice, provides a framework for education and training, facilitates implementation, and enables quality analysis. This review will address the state of US-guided vascular access, including current practice and future directions.

Pediatric macrophagic myofasciitis associated with motor delay.

BACKGROUND: Macrophagic myofasciitis (MMF) is a rare inflammatory myopathy characterized by accumulation of perifascicular macrophages without muscle fiber necrosis. Few sporadic pediatric cases have been described, and MMF is recognized as a possible reaction to intramuscular injections of aluminum-containing vaccines. The association of MMF and motor delay is unclear in the pediatric population. We report the clinical evaluation and follow-up of 4 young children with MMF and review of 4 cases previously reported of sporadic, pediatric MMF to better determine the possible association of sporadic MMF in children presenting with motor delay. PATIENTS AND METHODS: Described our 4 case reports in which we observed children presenting for evaluation of motor delay with unrevealing clinical and laboratory evaluations for common causes of motor delay and histopathological evaluations consistent with macrophagic myofasciitis. Muscle data was obtained by quadriceps muscle biopsy. RESULTS: Clinical presentations were similar in all children and were characterized by motor delay, hypotonia, and failure to thrive with an unrevealing evaluation for central nervous system disease, congenital, and mitochondrial myopathies. CONCLUSIONS: Our cases and those previously reported in the literature demonstrate MMF should be considered in the evaluation of children with failure to thrive, hypotonia, and muscle weakness, as clinical outcome appears to be favorable.

Rasmussen's syndrome and new-onset narcolepsy, cataplexy, and epilepsy in an adult.

We report a case of new-onset seizures and narcolepsy in a previously healthy 40-year-old man. He developed severe daytime somnolence and cataplexy over the course of a few months. Brain MRI was normal, and polysomnography with multiple sleep latency testing confirmed a diagnosis of narcolepsy. His HLA haplotype is DQB1*0602 and cerebrospinal fluid analysis showed no detectable hypocretin. Approximately 18 months later, he developed complex partial seizures. Further MRI showed a progressively enlarging lesion involving the left frontotemporal and insular areas. Pathology from a partial resection was consistent with Rasmussen's syndrome. Evaluation for tumor, infectious, and paraneoplastic etiologies was negative. There was no further progression of the residual lesion on serial MRI. Although the pathophysiologic bases of narcolepsy and Rasmussen's syndrome are unknown, they may have an autoimmune basis. This unique case of both disorders in a single patient suggests the possibility of a common underlying disease process.

Incidence of pericardial effusion in patients presenting to the emergency department with unexplained dyspnea.

OBJECTIVE: To evaluate the frequency of pericardial effusion in patients presenting to the emergency department (ED) with unexplained, new onset dyspnea. METHODS: This prospective observational study took place at an urban community hospital ED with a residency program and an annual census of 65,000 visits. Patients presenting between May 1999 and January 2000 with new-onset dyspnea were eligible if they lacked any pulmonary, infectious, hematological, traumatic, psychiatric, cardiovascular, or neuromuscular explanation for their dyspnea after ED evaluation. Patients received a focused echocardiogram by certified emergency physicians. Data were recorded on standardized data sheets and studies were taped for review. Effusions were categorized as small when the fluid stripe measured less than 10 mm. Moderate-sized effusions measured 10 to 15 mm. Large effusions measured more than 15 mm. RESULTS: One hundred three patients were enrolled. Median age was 56 years (IQR 44, 95% CI = 32 to 67). Fourteen patients (13.6%, 95% CI = 8% to 23%) had effusions. Four had large effusions that explained their dyspnea and were admitted to cardiology; two of these effusions were hemorrhagic, and two were viral in origin. Seven patients with small effusions were treated conservatively at home. Three patients had moderate-sized effusions; all were admitted but treated conservatively. CONCLUSIONS: While limited by small numbers, these preliminary data suggest that patients with unexplained dyspnea should be checked for pericardial effusion when bedside ED ultrasound is available.

Magnetic resonance imaging of ethyl-nitrosourea-induced rat gliomas: a model for experimental therapeutics of low-grade gliomas.

Human low-grade gliomas represent a population of brain tumors that remain a therapeutic challenge. Preclinical evaluation of agents, to test their preventive or therapeutic efficacy in these tumors, requires the use of animal models. Spontaneous gliomas develop in models of chemically induced carcinogenesis, such as in the transplacental N-ethyl-N-nitrosourea (ENU) rat model. However, without the ability to detect initial tumor formation, multiplicity or to measure growth rates, it is difficult to test compounds for their interventional or preventional capabilities. In this study Fisher-334 rats, treated transplacentally with ENU, underwent magnetic resonance imaging (MRI) examination in order to evaluate this approach for detection of tumor formation and growth. ENU-induced intracranial cerebral tumors were first observable in T2-weighted images beginning at 4 months of age and grew with a mean doubling time of 0.487 +/- 0.112 months. These tumors were found histologically to be predominately mixed gliomas. Two therapeutic interventions were evaluated using MRI, vitamin A (all-trans retinol palmitate, RP), as a chemopreventative agent and the anti-angiogenic drug SU-5416. RP was found to significantly delay the time to first tumor observation by one month (P = 0.05). No differences in rates of tumor formation or growth rates were observed between control and RP-treated groups. MRI studies of rats treated with SU-5416 resulted in reduction in tumor growth rates compared to matched controls. These results show that MRI can be used to provide novel information relating to the therapeutic efficacy of agents against the ENU-induced tumor model.

Distinctive molecular profiles of high-grade and low-grade gliomas based on oligonucleotide microarray analysis.

Astrocytomas are heterogeneous intracranial glial neoplasms ranging from the highly aggressive malignant glioblastoma multiforme (GBM) to the indolent, low-grade pilocytic astrocytoma. We have investigated whether DNA microarrays can identify gene expression differences between high-grade and low-grade glial tumors. We compared the transcriptional profile of 45 astrocytic tumors including 21 GBMs and 19 pilocytic astrocytomas using oligonucleotide-based microarrays. Of the approximately 6800 genes that were analyzed, a set of 360 genes provided a molecular signature that distinguished between GBMs and pilocytic astrocytomas. Many transcripts that were increased in GBM were not previously associated with gliomas and were found to encode proteins with properties that suggest their involvement in cell proliferation or cell migration. Microarray-based data for a subset of genes was validated using real-time quantitative reverse transcription-PCR. Immunohistochemical analysis also localized the protein products of specific genes of interest to the neoplastic cells of high-grade astrocytomas. Our study has identified a large number of novel genes with distinct expression patterns in high-grade and low-grade gliomas.

Unexplained exertional limitation: characterization of patients with a mitochondrial myopathy.

Exercise intolerance is a common complaint, the cause of which often remains elusive after a comprehensive evaluation. In this report, we describe 28 patients with unexplained dyspnea or exertional limitation secondary to biopsy-proven mitochondrial myopathies. Patients were prospectively identified from a multidisciplinary dyspnea clinic at a tertiary referral center. All patients were without underlying pulmonary, cardiac, or other neuromuscular disorders. Patients underwent history, physical examination, complete pulmonary function testing, respiratory muscle testing, cardiopulmonary exercise testing, and muscle biopsy. Results were compared with a group of normal control subjects. The estimated period prevalence was 8.5% (28 of 331). Spirometry, lung volumes, and gas exchange were normal in patients and control subjects. Compared with control subjects, the patient group demonstrated decreased exercise capacity (maximum achieved V O(2) 67 versus 104% predicted; p < 0.0001) and respiratory muscle weakness (PI(max) 77 versus 115% predicted; p = 0.001). These patients have a characteristic exercise response that was hyperventilatory (peak VE/V CO(2); 55 versus 42) and hypercirculatory (maximum heart rate - baseline heart rate/V O(2)max - baseline V O(2)max; 91 versus 41) compared to control subjects. Patients stopping exercise due to dyspnea (n = 16) (as compared with muscle fatigue, n = 11) displayed weaker respiratory muscles (Pdi(max) 61 versus 115 cm H(2)O; p = 0.01) and were more likely to reach mechanical ventilatory limitation (V Emax/ MVV 0.81 versus 0.58; p = 0.02). The sensation of dyspnea was related to indices of respiratory muscle function including respiratory rate and inspiratory flow. We conclude that mitochondrial myopathies are more prevalent than previously reported. The characteristic physiological profile may be useful in the diagnostic evaluation of mitochondrial myopathy.

Outcome in cardiac arrest patients found to have cardiac standstill on the bedside emergency department echocardiogram.

UNLABELLED: Patients presenting in cardiac arrest frequently have poor outcomes despite heroic resuscitative measures in the field. Many emergency medical systems have protocols in place to stop resuscitative measures in the field; however, further predictors need to be developed for cardiac arrest patients brought to the emergency department (ED). OBJECTIVE: To examine the predictive value of cardiac standstill visualized on bedside ED echocardiograms during the initial presentations of patients receiving cardiopulmonary resuscitation (CPR). METHODS: The study took place in a large urban community hospital with an emergency medicine residency program and a high volume of cardiac arrest patients. As part of routine care, all patients arriving with CPR in progress were subject to immediate and brief subxiphoid or parasternal cardiac ultrasound examination. This was followed by brief repeat ultrasound examination during the resuscitation when pulses were checked. A 2.5-MHz phased-array probe was used for imaging. Investigators filled out standardized data sheets. Examinations were taped for review. Statistical analysis included descriptive statistics, positive and negative predictive values, and likelihood ratios. RESULTS: One hundred sixty-nine patients were enrolled in the study. One hundred thirty-six patients had cardiac standstill on the initial echocardiogram. Of these, 71 patients had an identifiable rhythm on monitor. No patient with sonographically identified cardiac standstill survived to leave the ED regardless of his or her initial electrical rhythm. Cardiac standstill on echocardiogram resulted in a positive predictive value of 100% for death in the ED, with a negative predictive value of 58%. CONCLUSIONS: Patients presenting with cardiac standstill on bedside echocardiogram do not survive to leave the ED regardless of their electrical rhythms. This finding was uniform regardless of downtime. Although larger studies are needed, this may be an additional marker for cessation of resuscitative efforts.

Triage in the trauma bay with the focused abdominal sonography for trauma (FAST) examination.

Bedside ultrasonography has been applied to the evaluation of blunt trauma patients for over a decade. The Focused Abdominal Sonography for Trauma (FAST) examination has been used to successfully triage blunt trauma patients. Although not traditionally thought to be as useful in penetrating trauma patients, ultrasound can help determine the extent of injury especially of the heart. We present two cases of multiple-stabbing victims who arrived at our Level I trauma center at the same time, when our trauma system was particularly overburdened by multiple consecutive traumas. The FAST examination helped us to accurately determine which of the two patients required operative intervention first, despite that patient's appearance of relative hemodynamic stability in comparison to the other stabbing victim.

Proliferation index is related to patient age in glioblastoma.

Younger patients with glioblastomas have a significantly better prognosis than do older patients. To determine whether patient age might be related to proliferation of glioblastoma cells, glioblastomas from patients of different ages were stained with the Molecular Immunology Borstel number 1 antibody to detect proliferating cells. Younger patient age was a significant predictor of a low Molecular Immunology Borstel number 1 proliferation index (p = 0.0001). This previously unreported association favors an intrinsic difference in the type of glioblastomas that afflict younger patients.

Ultrasound-guided breast abscess aspiration in a difficult case.

Although ultrasound guidance is occasionally used for abscess detection and aspiration by our radiology colleagues, this is still a very uncommon application in the emergency department (ED). A case is presented of a patient with a difficult-to-drain, recurrent breast abscess. The consulting surgeon was unable to localize the abscess after 15 attempts at aspiration in the ED and requested ultrasound guidance from the attending emergency physician for the procedure. Drainage of the abscess was successfully completed in one attempt with real-time visualization and guidance of the needle. The consulting surgeon requested that ultrasound be available at the patient's follow-up visit to the ED.

The gene for the axonal cell adhesion molecule TAX-1 is amplified and aberrantly expressed in malignant gliomas.

The human TAX-1 gene encodes a Mr 135,000 glycoprotein that is transiently expressed on the surface of a subset of neurons during development and is involved in neurite outgrowth. The TAX-1 gene has been mapped to a region on chromosome 1 that has been implicated in microcephaly and the Van der Woude syndrome. Using restriction landmark genome scanning to search for amplified genes in gliomas, we found TAX-1 to be amplified in 2 high-grade gliomas among a group of 26 gliomas investigated. Real-time reverse transcription-quantitative PCR analysis detected high levels of TAX-1 mRNA in glial tumors, even in the absence of TAX-1 gene amplification. Immunohistochemical analysis revealed abundant levels of TAX-1 in neoplastic glial cells of glioblastoma multiforme tumors. Because glial tumors are highly invasive and in view of the role of TAX-1 in neurite outgrowth, we investigated the potential role of TAX-1 in glioma cell migration. Using an in vitro assay, we found that the migration of glioma tumor cells is profoundly reduced in the presence of either an anti-TAX-1 antibody or a TAX-1 antisense oligonucleotide. Our findings suggest that TAX-1 plays a role in glial tumorigenesis and may provide a potential target for therapeutic intervention.

Emergency ultrasonography in the evaluation of the acute scrotum.

Acute scrotal pain accounts for approximately 0.5% of total emergency department (ED) visits. Despite this relatively low percentage, these patients can present a considerable challenge to the treating emergency physician (EP) since the etiologies of acute scrotal pain range from organ-threatening disease to minor idiopathic pain. Few data exist on EP use of bedside ultrasound to evaluate scrotal pain, but there is some suggestion that this may represent a beneficial future application for emergency ultrasonographers. This paper briefly describes the technology and technique involved with the performance of testicular ultrasound examination and briefly discusses its potential application at bedside in the ED.

Emergency evaluation of patients presenting with acute scrotum using bedside ultrasonography.

UNLABELLED: Acute scrotal pain is not a rare emergency department (ED) complaint. Traditional reliance on medical history and physical examination can be precarious as signs and symptoms can overlap in various etiologies of acute scrotal pain. OBJECTIVE: To determine the accuracy with which emergency physicians (EPs) using bedside ultrasonography are able to evaluate patients presenting to the ED with acute scrotal pain. METHODS: The study was performed at an urban community hospital ED with a residency program and an annual census of 70,000. A retrospective chart review identified 36 patients who presented with complaints of acute scrotal pain and were evaluated by EPs using bedside ultrasound. A 5.0- or 7.5-MHz linear-array transducer with color and power Doppler capability was used to scan the scrotum. Patients were seen between July 1998 and September 1999. Diagnoses were verified by radiology or surgery. Sensitivity and specificity with 95% confidence intervals were calculated. RESULTS: The EP ultrasound examinations agreed with confirmatory studies for 35 of 36 patients, resulting in a sensitivity of 95% (95% CI = 0.78 to 0.99) and a specificity of 94% (95% CI = 0.72 to 0.99). Diagnoses included three testicular torsions, six cases of epididymitis, four cases of orchitis, one testicular fracture, three hernias, three hydroceles, and 15 normal examinations. One case of epididymitis was misdiagnosed as an epididymal mass. CONCLUSIONS: This study suggests that EPs using bedside ultrasonography are able to accurately diagnose patients presenting with acute scrotal pain. In addition, they appear able to differentiate between surgical emergencies, such as testicular torsion, and other etiologies.

Polymyositis evolving after rhabdomyolysis associated with HMG-CoA reductase inhibitors: a report of two cases.

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors are commonly used for treatment of hyperlipidemia and its deleterious effects. Myotoxicity has been associated with use of these agents. We report two cases of inflammatory myopathy in patients receiving these agents that did not respond to drug withdrawal and required immunosuppressive treatment. One of these patients developed an antibody to histidyl tRNA synthetase or Jo-1, an autoantibody associated with idiopathic inflammatory myopathies. We suggest that HMG-CoA reductase inhibitor-associated myotoxicity may trigger an immune-mediated inflammatory myopathy. Patients whose muscle abnormalities do not resolve with drug withdrawal should be considered for muscle biopsy.

The pathology of REM sleep behavior disorder with comorbid Lewy body dementia.

A patient with REM sleep behavior disorder who subsequently developed probable Lewy body dementia is now reported to have a definite pathologic diagnosis of Lewy body dementia. Examination of brain revealed Lewy bodies as well as marked neuronal loss in brainstem monoaminergic nuclei-particularly locus coeruleus and substantia nigra-that inhibit cholinergic neurons in the pedunculopontine nucleus mediating atonia during REM sleep.

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.

Do emergency physicians save time when locating a live intrauterine pregnancy with bedside ultrasonography?

OBJECTIVE: To determine whether patients presenting to the emergency department (ED) with first-trimester pregnancy complications have a decreased length of stay (LOS) when a live intrauterine pregnancy (IUP) is diagnosed by emergency physicians (EPs). METHODS: This study was performed at an urban community ED with a residency program and an annual census of 65,000. A retrospective chart review from October 1995 to August 1998 identified 1,419 patients who received ultrasound examinations confirming live IUP in the first trimester with pain and/or bleeding. Two hundred seventy-seven of these patients received their ultrasound examinations from EPs; 1, 142 patients received a study from radiology and were not scanned by EPs. The LOSs for the two groups were compared and defined as the time from being placed into a room to discharge from the ED. Significance was determined using a two-tailed t-test. Median times with confidence intervals were calculated. RESULTS: When patients had a live IUP confirmed by an EP, the median LOS was 21% (59 min) less than those who received an ultrasound examination by radiology (p = 0.0001; 95% CI = 49 min to 1 hr 17 min). When evaluated by time of day, patients who presented after hours (6 PM to 6 AM) and were scanned by EPs spent 28% (1 hr 17 min) less time in the ED (p = 0.0001; 95% CI = 55 min to 1 hr 37 min). CONCLUSIONS: Emergency physicians identifying live IUP with bedside ultrasonography significantly decreased patients' LOSs in the ED. The decrease in LOS was most apparent for patients presenting during evening and nighttime hours.

Sinonasal undifferentiated carcinoma: case series and review of the literature.

OBJECTIVE AND IMPORTANCE: We report on four cases of sinonasal undifferentiated carcinoma (SNUC), a relatively newly described clinicopathological entity of the nasal cavity and paranasal sinuses. SNUC tends to present with advanced-stage disease, often with intracranial invasion, and requires an aggressive treatment approach that includes surgical resection. A review of the literature identified several reports of SNUC in pathology and otolaryngology journals since its initial description in 1986, but no report has yet appeared in the neurosurgery literature. CLINICAL PRESENTATION: Four patients presented with various symptoms related to the nose and/or orbit, including one or more of the following: obstruction, epistaxis, decreased visual acuity, diplopia, and pain. All patients were noted to have masses in the nasal cavity or paranasal sinuses, with or without intracranial extension. INTERVENTION: All four patients underwent multimodal treatment with chemotherapy, radiotherapy (60-65 Gy), and aggressive surgical resection via a combined bifrontal craniotomy and a subcranial approach to the anterior cranial fossa. Three of four patients died as a result of their disease, an average of 15 months after diagnosis. Only one patient remains alive, although with metastatic intracranial disease, at 24 months after diagnosis. CONCLUSION: SNUC is a rare neoplasm with a poor prognosis despite an aggressive multimodal approach to treatment. On the basis of our experience, we advocate radical resection as part of the initial combined therapy for patients who present with locally advanced, nonmetastatic disease but we suggest reserving surgery for patients with early brain invasion until there has been a radiographically proven central nervous system response to adjuvant therapy.