RESUMEN
Patients with acute cardiogenic pulmonary edema (ACPE) are commonly seen in the emergency department (ED). Although the majority of patients respond to conventional medical therapy, some patients require at least temporary ventilatory support. Traditionally, this has been accomplished via endotracheal intubation and mechanical ventilation, an approach that is associated with a small but significant rate of complications. The past 2 decades have witnessed increasing interest in methods of noninvasive ventilatory support (NVS), notably continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BiPAP). We review the physiological consequences, clinical efficacy, and practical limitations of CPAP and BiPAP in the management of ACPE.
Asunto(s)
Tratamiento de Urgencia/métodos , Cardiopatías/complicaciones , Respiración con Presión Positiva/métodos , Edema Pulmonar/etiología , Edema Pulmonar/terapia , Enfermedad Aguda , Hemodinámica , Humanos , Intubación Intratraqueal/efectos adversos , Monitoreo Fisiológico , Selección de Paciente , Respiración con Presión Positiva/instrumentación , Circulación Pulmonar , Edema Pulmonar/sangre , Respiración Artificial/efectos adversos , Resultado del TratamientoRESUMEN
OBJECTIVES: To describe and compare national trends in ED use by statistical analyses on data from the 1992 to 1996 National Hospital Ambulatory Medical Care Survey (NHAMCS) with a special interest in factors related to nonurgent visits. METHODS: The NHAMCS collects data for ED visits using a four-stage national probability sample. Data from 135,723 ED visits in 1992-1996 were analyzed using the chi-square test for proportions with logistic regression modeling for multivariate analysis. RESULTS: More than half of the ED visits were considered nonurgent. There was a decreasing trend for nonurgent ED visits over the first three years of the sample (54.0% to 52.1%, p < 0.05). The proportion of ED visits for nonurgent care bounced back in 1995 (54.7%) and 1996 (54.1%). Significant variation existed in the proportion of nonurgent care visit based on disease category, age, race, and insurance coverage status. Marked variation in nonurgent visits also existed among geographic regions and types of hospital ownership. CONCLUSIONS: Analyses of data from the NHAMCS identify trends in ED use. The study of nonurgent ED visits with this database has inherent methodologic problems such as retrospective coding and geographic coding inconsistency. Since the nonurgent visit is clearly linked to certain social-demographic factors, addressing these underlying issues by establishing a comprehensive health care system is a priority.
Asunto(s)
Servicio de Urgencia en Hospital/estadística & datos numéricos , Mal Uso de los Servicios de Salud/estadística & datos numéricos , Adulto , Anciano , Distribución de Chi-Cuadrado , Intervalos de Confianza , Medicina de Emergencia/normas , Medicina de Emergencia/tendencias , Femenino , Encuestas de Atención de la Salud , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Estados UnidosRESUMEN
STUDY OBJECTIVE: To evaluate intramuscular dihydroergotamine in direct comparison with opioid analgesia in the treatment of acute migraine headache. METHODS: This was a prospective, multicenter, double-blind trial performed in the emergency departments of 11 general hospitals in the United States. One hundred seventy-one patients between the ages of 18 and 60 years who presented to the ED with acute migraine headache were enrolled. Patients were randomly assigned to receive either 1 mg dihydroergotamine (DHE) or 1.5 mg/kg meperidine (MEP) by intramuscular injection. The anti-nauseant hydroxyzine (H) was coadministered in both treatment groups. RESULTS: One hundred fifty-six patients were evaluable. Treatment groups were comparable in sample size, demographics, and baseline measurements of headache pain. Reduction of headache pain as measured on a 100-mm visual analog scale was 41+/-33 mm (53.5% reduction) for the DHE group, and 45+/-30 mm (55.7% reduction) for the MEP group at 60 minutes after treatment (difference=2.2%; 95% confidence interval [CI] -10%, 14.5%; P=.81). Reduction in the severity of nausea and improvement in functional ability were similar between treatment groups. Central nervous system adverse events were less common in the DHE group (DHE 23.5% versus MEP 37.6%, difference-14.1%: 95% CI -28%, 0%). In particular, dizziness was reported less commonly with DHE than MEP (2% versus 15%, difference=-13%: 95% CI -21%, -5%). CONCLUSION: In this prospective, double-blind trial of a convenience sample of ED patients randomly assigned to one of two treatment regimens, DHE and MEP were comparable therapies for acute migraine. The use of DHE avoids several problems associated with opioid analgesia, including dizziness.
Asunto(s)
Analgésicos no Narcóticos/uso terapéutico , Analgésicos Opioides/uso terapéutico , Antieméticos/uso terapéutico , Dihidroergotamina/uso terapéutico , Hidroxizina/uso terapéutico , Meperidina/uso terapéutico , Trastornos Migrañosos/tratamiento farmacológico , Enfermedad Aguda , Adolescente , Adulto , Analgésicos no Narcóticos/administración & dosificación , Analgésicos no Narcóticos/efectos adversos , Analgésicos Opioides/administración & dosificación , Analgésicos Opioides/efectos adversos , Antieméticos/administración & dosificación , Antieméticos/efectos adversos , Dihidroergotamina/administración & dosificación , Dihidroergotamina/efectos adversos , Método Doble Ciego , Combinación de Medicamentos , Servicio de Urgencia en Hospital , Femenino , Estudios de Seguimiento , Humanos , Hidroxizina/administración & dosificación , Hidroxizina/efectos adversos , Inyecciones Intramusculares , Masculino , Meperidina/administración & dosificación , Meperidina/efectos adversos , Persona de Mediana Edad , Náusea/tratamiento farmacológico , Dimensión del Dolor , Estudios Prospectivos , Factores de TiempoRESUMEN
Future therapies for septic shock will likely center around the antagonism of toxins released by the infecting organism and the modification of the host response to such toxins. Until such therapies become available, patient salvage will continue to depend on the maintenance of effective circulatory function until the source of infection is eliminated. With the recognition that resuscitation is best directed toward optimization of peripheral oxygen metabolism, reduction of mortality has been achieved in recent years through the early application of invasive hemodynamic monitoring and the aggressive manipulation of the determinants of peripheral oxygen delivery. Volume loading to improve myocardial performance, transfusion to increase the oxygen carrying capacity of the blood, intubation and mechanical ventilation to maximize arterial oxygen saturation, sedation to limit unnecessary peripheral oxygen use, and pharmacologic support of supranormal peripheral perfusion requirements are the essential tenets of successful management.
Asunto(s)
Enfermedades Cardiovasculares/etiología , Sepsis/complicaciones , Choque Séptico/complicaciones , Enfermedades Cardiovasculares/fisiopatología , Causas de Muerte , Humanos , Sepsis/mortalidad , Choque Séptico/mortalidadRESUMEN
Burns represent a major cause of accidental death in industrialized countries. Before the recognition of the key role of aggressive volume resuscitation in successful management, early mortality was common secondary to burn shock. Salvage of patients with major burns is optimized only if the pathophysiology of burn injury and the time course of hemodynamic derangements is understood. The effects of the neuroendocrine response to burning and the release of mediators from the burn wound on intravascular volume status, ventricular function, peripheral vascular tone, and metabolism must be addressed. In the early postburn period, crystalloid should be administered at a rate prescribed by any of several burn resuscitation formulas. The Parkland formula, providing 4 mL/kg/% burn over the first 24 hours, is the most widely used and has met with consistent success when used as a guideline for resuscitation over the early period of management. Colloid may be added to minimize resuscitation volumes and reduce edema once capillary endothelial competency has been restored. Ongoing resuscitation should be modified based on the clinical response of the patient, primarily the urine output, heart rate, and base deficit. In selected high-risk patients and in those failing resuscitation to clinical goals, invasive hemodynamic monitoring should be used to refine fluid management and identify those patients who may benefit from cardiotonic drugs. The potential contribution of carbon monoxide or cyanide intoxication to hemodynamic instability should be considered in all patients with a compatible history, including a history of inadequate response to treatment. With resolution of the phase of potential burn shock, the increased metabolic needs of the patient and the demands imposed by those needs on the cardiovascular system should be anticipated and supported.
Asunto(s)
Quemaduras/complicaciones , Choque Traumático , Antioxidantes/uso terapéutico , Cardiotónicos/uso terapéutico , Fluidoterapia , Hemodinámica/fisiología , Humanos , Oxigenoterapia Hiperbárica , Resucitación , Choque Traumático/etiología , Choque Traumático/fisiopatología , Choque Traumático/terapiaRESUMEN
Electrical injury is uncommon, and cardiac involvement occurs in a minority of patients who are injured. Cardiovascular complications in the electrically injured patient, however, can be devastating. Because the presentation of electrical injury to the heart can be atypical in nature, delayed in onset, or obscured by other trauma, caution must be exercised in the interpretation of initial symptoms, ECGs, monitor strips, and cardiac enzymes. Whenever there is doubt concerning the presence of cardiovascular injury, the patient should be monitored. When cardiac complications are in evidence, expectant management is generally sufficient. When specific management of cardiac arrest, other dysrhythmias, myocardial necrosis, hypertension, or conduction abnormalities is required, standard therapeutic regimens are generally appropriate. In managing apparent acute myocardial infarction, however, the possibility that the injury is not of ischemic origin must be considered. Reperfusion techniques should be applied only when occlusive coronary thrombosis is strongly suspected or angiographically confirmed. The risk of developing chronic cardiac disease after electrical injury to the heart is unknown. Patients who sustain cardiovascular injuries should be followed for at least 12 months and avoid elective surgery for 6 months after the incident.
Asunto(s)
Arritmias Cardíacas/etiología , Traumatismos por Electricidad/complicaciones , Cardiopatías/etiología , Traumatismos por Acción del Rayo/complicaciones , HumanosRESUMEN
STUDY OBJECTIVES: This study tested the hypothesis that serial creatine phosphokinase (CK)-MB sampling in the emergency department can identify acute myocardial infarction (AMI) in patients presenting to the ED with chest pain and nondiagnostic ECGs. DESIGN: Patients more than 30 years old who were evaluated initially in the ED and hospitalized for chest pain were studied. Serial CK-MB levels were analyzed prospectively using a rapid serum immunochemical assay for identification of AMI patients in the ED. Presenting ECGs showing new, greater than 1-mm ST elevation in two or more contiguous leads were considered diagnostic for AMI. All other ECGs were considered nondiagnostic ECGs. CK-MB levels were determined at ED presentation and hourly for three hours (total of four levels). Patients with at least one level of more than 7 ng/mL were considered to have a positive enzyme study. The in-hospital diagnosis of AMI was determined by the development of typical serial ECG changes or separate standard cardiac enzyme changes after admission. SETTING: Eight tertiary-care medical center hospitals. METHODS AND MAIN RESULTS: Of the 616 study patients, 108 (17.5%) were diagnosed in the hospital as AMI; 69 of these AMI patients (63.9%) had nondiagnostic ECGs in the ED. Of the patients with nondiagnostic ECGs, 55 (sensitivity, 79.7%) had a positive ED serial CK-MB enzyme study within three hours after presentation. Combining serial ED CK-MB assay results with diagnostic ECGs yielded an 88.4% sensitivity for AMI detection within three hours of ED presentation. The predictive value of a negative serial ED enzyme study for no AMI was 96.2% (specificity, 93.7%). CONCLUSION: Serial CK-MB determination in the ED can help identify AMI patients with initial nondiagnostic ECGs. Use of serial CK-MB analysis may facilitate optimal in-hospital disposition and help guide therapeutic interventions in patients with suspected AMI despite a nondiagnostic ECG.
Asunto(s)
Dolor en el Pecho/etiología , Creatina Quinasa/sangre , Electrocardiografía , Infarto del Miocardio/diagnóstico , Adulto , Femenino , Humanos , Isoenzimas , Masculino , Infarto del Miocardio/enzimología , Valor Predictivo de las Pruebas , Curva ROC , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
Attempts were made to determine the central projections of ganglion cells innervating individual semicircular ducts in the monkey by implanting or injecting tritiated amino acids (leucine and/or proline), or horseradish peroxidase (HRP), selectively into a single ampulla. Central transport via the vestibular ganglion in animals receiving isotope implants or injections fell into three categories: (1) transport from ganglion cells innervating all receptive elements of the labyrinth, (2) transport from ganglion cells innervating the three semicircular ducts, and (3) transport from cells of the inferior vestibular ganglion innervating the posterior semicircular duct. Transneuronal transport of isotope was observed in secondary vestibular fibers in animals where proline was used and survival exceeded 12 days. Transneuronal labeling of secondary auditory fibers was independent on the [3H]amino acid used, and occurred with survivals of 10 or more days. HRP implanted into the ampulla of the lateral semicircular duct in several animals produced retrograde transport to efferent vestibular and cochlear neurons, but did not result in transganglionic labeling of primary vestibular or auditory fibers. Primary vestibular fibers terminate throughout the superior (SVN) and medial vestibular nuclei (MVN). Within SVN, terminals are most pronounced in its central large-celled portion, but extend into peripheral parts of the nucleus, except for a small medial area near its junction with the oral pole of MVN. Primary projections to MVN are homogenously distributed throughout the nucleus excepting a small circular area of sparse terminals along its ventral margin. Primary vestibular afferents terminate mainly in rostral and caudal portions of the inferior vestibular nucleus (IVN), but do not reach cell group 'f'. Projections to the lateral vestibular nucleus (LVN) are restricted to its ventral part. Primary projections to the accessory vestibular nuclei reach the interstitial nucleus of the vestibular nerve (NIVN) and cell group 'y'. Fibers project beyond the vestibular nuclei (VN) to terminate ipsilaterally in the accessory cuneate nucleus (ACN), the subtrigeminal lateral reticular nucleus (SLRN), and well-defined portions of the reticular formation (RF). Projections to SVN and MVN are derived primarily from ganglion cells innervating the semicircular ducts, while projections to caudal IVN, cell group 'y' and ACN are related mainly to macular portions of the vestibular ganglion. NIVN receives both macular and duct afferents.(ABSTRACT TRUNCATED AT 400 WORDS)
Asunto(s)
Tronco Encefálico/fisiología , Cerebelo/fisiología , Canales Semicirculares/inervación , Vías Aferentes/fisiología , Animales , Autorradiografía , Transporte Axonal , Leucina/metabolismo , Macaca fascicularis , Macaca mulatta , Prolina/metabolismo , Saimiri , Tritio , Núcleos Vestibulares/fisiologíaRESUMEN
Attempts were made to determine the afferent and efferent connections of the medial (MVN), inferior (IVN) and lateral (LVN) vestibular nuclei (VN) in the cat and monkey using retrograde and anterograde axoplasmic transport technics. Injections of HRP and [3H]amino acids were made selectively into MVN, IVN and LVN and into: (1) MVN and IVN, (2) LVN and IVN and (3) all 4 VN. Contralateral afferents to MVN arise from (1) the nuclei prepositus (NPP) and intercalatus (NIC), (2) all parts of MVN and cell group 'y' and (3) parts of the superior vestibular nucleus (SVN), IVN and the fastigial nucleus (FN). Ipsilateral projections to MVN arise from: (1) a central band of the flocculus and the nodulus and uvula, (2) the interstitial nucleus of Cajal (INC), and (3) visceral nuclei of the oculomotor nuclear complex (OMC). Efferent projections of MVN are to: (1) the ipsilateral supraspinal nucleus (SSN), and (2) the contralateral central cervical nucleus (CCN), MVN, SVN, cell group 'y', the rostroventral region of LVN, the trochlear nucleus (TN) and the INC. Projections to the abducens nuclei (AN) and the OMC are bilateral. Some ascending fibers in the cat cross within the OMC. In the monkey fibers from MVN end in a central band of the ipsilateral flocculus. Afferents to IVN arise ipsilaterally from SVN, the nodulus, the uvula and the anterior lobe vermis. Contralateral afferents arise from: (1) parts of CCN, MVN, SVN, IVN and cell group 'y' and (2) the central third of the FN. IVN receives bilateral projections from the perihypoglossal nuclei (PH) and the visceral nuclei of the OMC. Efferents from IVN project: (1) ipsilaterally to nucleus beta of the inferior olive, (2) contralaterally to parts of MVN, SVN and cell group 'y' and (3) bilaterally to the paramedian reticular nuclei. No commissural fibers interconnect cell groups 'f' and 'x'. Ascending fibers from IVN terminate contralaterally in the TN and the OMC. In the monkey fibers from IVN terminate in the ipsilateral nodulus, uvula and anterior lobe vermis; no fibers project to FN in either the cat or the monkey. Afferents to the LVN arise primarily from the ipsilateral anterior lobe vermis and bilaterally from rostral parts of the FN. No commissural fibers interconnect the LVN. Projections of the LVN are primarily to spinal cord via the vestibulospinal tract (VST); collaterals of the VST terminate in the lateral reticular nucleus (LRN). Ascending uncrossed projections from LVN in the cat terminate in the medial rectus subdivision of the OMC.(ABSTRACT TRUNCATED AT 400 WORDS)
Asunto(s)
Gatos/fisiología , Cebidae/fisiología , Saimiri/fisiología , Núcleos Vestibulares/fisiología , Vías Aferentes/fisiología , Animales , Mapeo Encefálico , Vías Eferentes/fisiología , Peroxidasa de Rábano Silvestre , Lectinas , Transmisión Sináptica , Aglutininas del Germen de TrigoRESUMEN
Comparisons were made of projections from the vestibular nuclei (VN) and abducens internuclear neurons (AIN) to cell group A of the medial rectus subdivision (MRS) of the oculomotor nuclear complex. Cell group A, the major component of the MRS, receives projections only from the ipsilateral VN and the contralateral AIN. Neither ipsilateral vestibular projections to cell group A, arising from the medial vestibular nucleus, nor projections from MVN to the opposite abducens nucleus, match the massive projection of AIN to the MRS.
Asunto(s)
Nervio Abducens/citología , Nervio Vestibular/citología , Aminoácidos/metabolismo , Animales , MacacaRESUMEN
Attempts were made to determine the afferent and efferent connections of the subthalamic nucleus (STN) in the monkey using retrograde and anterograde axoplasmic transport technics. Following HRP injections limited to the STN, label was transported to arrays of cells adjacent, and parallel, to the lateral medullary lamina in the rostral two thirds of the lateral pallidal segment (LPS). Only sparse label was transported to cells of the pedunculopontine nucleus (PPN) and the locus ceruleus (LC). No enzyme was transported across the midline, or to the striatum, medial pallidal segment (MPS), thalamus, substantia nigra (SN) or dorsal nucleus of the raphe (DNR). HRP injected into portions of both the STN and SN produced retrograde transport of the enzyme to cells in parallel arrays in the LPS related rostrocaudally to the injection site. Additional enzyme transport was seen in cells of the striatum, the DNR and the PPN. Only a few isolated cells were labeled in the sensorimotor cortex. Efferent connections of the STN were studied in monkeys in which [3H]amino acids were injected hydraulically or iontophoretically into the STN. Isotope traced in serial autoradiographs was distributed to: (1) both segments of the globus pallidus (GP) in arrays parallel to the medullary laminae, and (2) the pars reticulata of SN (SNpr). The greatest number of terminals was found in the MPS. Fibers from the rostral part of the STN descended along the dorsal border of the SN and projected ventrally to terminations in the SNpr. No isotope was transported across the midline, or to the striatum, thalamus, DNR or PPN. Isotope injected into both the STN and SN produced similar transport to the GP and transport via nigral efferent fibers to: (1) portions of the striatum, (2) specific thalamic nuclei (VAmc, VLm, DMpl), (3) deep and middle gray layers of the superior colliculus and (4) PPN. Control studies indicated that [3H]amino acids injected only into the SN were transported to PPN. HRP injected into PPN produced profuse retrograde transport in cells of the MPS and SNpr and distinct label in a few cells of the zona incerta and STN. These data suggest that the STN receives its major subcortical input from cell of the LPS arranged in arrays which have a rostrocaudal organization. No cells of the MPS or SN project to the STN. The output of the STN is to both segments of the GP and SNpr. Major subcortical projections to PPN arise from the MPS and SNpr, but afferents also arise from other sources. The major projection of PPN is to SN.