Prehospital use of continuous positive airway pressure (CPAP) for presumed pulmonary edema: a preliminary case series.

OBJECTIVE: To describe the prehospital use of a continuous positive airway pressure (CPAP) system for the treatment of acute respiratory failure presumed to be due to cardiogenic pulmonary edema. METHODS: Prospective case-series analysis. Paramedics administered CPAP via face mask at 10 cm H2O to patients believed to be in cardiogenic pulmonary edema and in imminent need of endotracheal intubation (ETI). Data from run sheets and hospital records were analyzed for treatment intervals, vital signs, complications, admitting diagnoses, need for ETI, and mortality. RESULTS: Nineteen patients received prehospital CPAP therapy. Mean duration of therapy was 15.5 minutes. Pre- and post-therapy pulse oximetry was available for 15 patients and demonstrated an increase from a mean of 83.3% to a mean of 95.4%. None of the patients were intubated in the field. Two patients who did not tolerate the CPAP mask required ETI upon arrival in the emergency department (ED); an additional five patients required ETI within 24 hours. There was one death in the series and two additional adverse events (one aspiration pneumonia, one pneumothorax); none of these were attributable to the use of CPAP. The diagnosis of cardiogenic pulmonary edema was corroborated by the ED or in-hospital physician in 13 patients (68%). Paramedics reported no technical difficulties with the CPAP system. CONCLUSION: For patients with acute respiratory failure and presumed pulmonary edema, the prehospital use of CPAP is feasible and may avert the need for ETI. Future controlled studies are needed to assess the utility and cost-effectiveness of prehospital CPAP systems.

Can emergency department triage nurses predict patients' dispositions?

Early recognition of inpatient bed requirements might be helpful in expediting the admission process through the emergency department (ED). With this in mind, we asked whether ED triage nurses could accurately predict patients' in-hospital dispositions. A prediction was recorded for 521 ED patients, of whom 107 (20.5%) were ultimately admitted to the hospital. Nurses correctly anticipated 66 of 107 hospital admissions (sensitivity = 61.7%, PPV = 61.7%). With respect to predicting specific levels of inpatient care, nurses correctly anticipated 17 of 45 floor admissions (sensitivity = 37.8%, PPV = 34.7%), 14 of 33 step-down/monitored unit admissions (sensitivity = 42.4%, PPV = 48.3%), and 12 of 24 intensive care unit admissions (sensitivity = 50.0%, PPV = 66.7%). Lacking in sensitivity and positive predictive value, particularly with regard to specific levels of inpatient care, triage nurses' predictions may have limited potential to expedite the admission process.

Evaluation and management of acutely decompensated chronic heart failure in the emergency department.

A wide range of patients with symptomatic heart failure seek treatment in the emergency department. While there is no single approach to the diversity of patients with acutely decompensated heart failure, certain overarching principles apply. For patients with acute pulmonary edema or cardiogenic shock, the first priority must be rapid stabilization and treatment of reversible problems. For patients with less dramatic presentations, a more systematic search for precipitating factors may be required. Therapy, in general, is directed at reversing dyspnea and/or hypoxemia caused by pulmonary edema, improving systemic perfusion, and reducing myocardial oxygen demand. While morphine and diuretics still have their traditional roles, vasodilators and inotropic agents play an increasingly important part in the modern pharmacologic approach to decompensated heart failure in the emergency department. After evaluation and stabilization in the emergency department, most patients will require hospital admission, although a subset of low-risk patients may be appropriate for discharge to home following a period of observation. Strategies to optimize emergency department care are likely to have an impact upon patient outcomes and upon resource utilization. (c)2001 by CHF, Inc.

Massive hemoperitoneum due to rupture of a retroperitoneal varix.

Intra-abdominal hemorrhage from ruptured varices is an unusual, life-threatening complication of portal hypertension. We present the case of a 58-year-old man with alcoholic cirrhosis who presented with increasing abdominal girth, hypovolemic shock, and profound anemia due to rupture of a retroperitoneal varix into the peritoneal cavity. The clinical presentation of this rare problem is remarkably consistent among published reports. Early recognition may help the treating physician reduce the likelihood of a catastrophic outcome.

Continuous and bilevel positive airway pressure in the treatment of acute cardiogenic pulmonary edema.

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.

Patient refusal of care in the out-of-hospital setting.

A case vignette of out-of-hospital refusal of emergency care is reported with accompanying discussion. This case illustrates the challenges faced by out-of-hospital emergency care personnel in these scenarios and provides guidance to the emergency physician and emergency medical technician. Recommendations are provided for preparing the emergency medical services system to handle these cases.

Proton secretion by the sodium/hydrogen ion antiporter in the human neutrophil.

The reducing equivalents used by the human neutrophil respiratory burst oxidase are derived from NADPH generated by the hexose monophosphate shunt. The CO2 generated by the HMP shunt is spontaneously hydrated and the protons (H+) are secreted upon the dissociation of carbonic acid. The mechanism and significance of H+ secretion by the resting and stimulated neutrophil was investigated. A basal rate of H+ secretion by resting neutrophils observed in a choline buffer was augmented with the addition of sodium (Na+) (Km for Na+ was 3.22 +/- 0.32 mM). Amiloride, a Na+/H+ antiporter inhibitor, reduced H+ secretion in Na+-containing buffers with a Ki = 1.02 microM. This Na+/H+ exchange mechanism was also operative in cells stimulated with a variety of agonists, and an increased H+ flux, relative to resting cells, was observed at higher Na+ concentrations. Cytoplasts incorporating acridine orange were also used to assess Na+-H+ flux. Cytoplasts were used to avoid alteration of the fluorescent pH probe by HOCl formed in intact neutrophils. Alkalinization of the cytoplasm was dependent on extracellular Na+ in concentrations similar to that found to augment H+ secretion in intact cells. Also, amiloride competitively inhibited H+ secretion by the cytoplasts. Both superoxide (O2-) production and lysozyme release in cells stimulated with opsonized zymosan or concanavalin A was significantly inhibited in the absence of Na+, restored to normal with the addition of Na+ in low concentrations, and inhibited again in the presence of amiloride. A Na+/H+ antiporter similar to that found in other cell types is present in the human neutrophil and appears linked to activation of the respiratory burst and degranulation.