The epidemiology and outcome of prehospital respiratory distress.

Objectives Patients with respiratory distress often seek emergency medical care and are transported by emergency medical services (EMS). EMS encounters with patients in respiratory distress have not been well described. The study objective was to characterize the epidemiology of prehospital respiratory distress and subsequent patient outcomes. Methods This was a population-based cohort study of noninjured adults transported by EMS to any of 16 hospitals between 2002 and 2006. EMS records were linked to hospital administrative data for encounters categorized by EMS personnel as primarily “respiratory distress” in nature. The authors described prehospital patient and encounter characteristics, interventions, hospital discharge diagnoses (using ICD-9-CM codes), and patient outcomes. The association between prehospital variables, defined a priori, and hospital admission were described using multivariable logistic regression. Results There were 166,908 EMS encounters, of which 19,858 were for respiratory distress (11.9%, 95% confidence interval [CI] = 11.7% to 12.1%). Half of the patients were admitted to the hospital (n = 9,964), one-third of those required intensive care (n = 3,094), and 10% of hospitalized patients died prior to discharge (n = 948). Fifteen percent of hospitalized patients received invasive mechanical ventilation (n = 1,501), over half of whom were intubated during prehospital care (n = 896). The most common primary discharge diagnoses among prehospital respiratory distress patients admitted to the hospital were congestive heart failure (CHF; 16%), pneumonia (15%), chronic obstructive pulmonary disease (COPD; 13%), and acute respiratory failure (13%). Few EMS patients with respiratory distress were coded with a primary diagnosis of acute myocardial infarction (3.5%, n = 350) or underwent percutaneous coronary intervention (0.7%, n = 71). In a multivariable regression model, prehospital factors that were independently associated with hospital admission included initial respiratory rate (odds ratio [OR] = 1.29 for an increase in respiratory rate of five breaths/min, 95% CI = 1.24 to 1.35) and an encounter that originated at a nursing home (OR = 2.80, 95% CI = 2.28 to 3.43). Conclusions In a population-based cohort, EMS personnel commonly encounter prehospital respiratory distress among medical patients, many of whom require hospital admission to the intensive care unit. These data may help to inform targeted therapy or more efficient triage and transport decisions. Resumen Objetivos Los pacientes con dificultad respiratoria a menudo demandan atencion medica urgente, y son transportados por los Servicios de Emergencias Medicas (SEM). Las atenciones del SEM con los pacientes con dificualtad respiratoria no han sido bien descritas. El objetivo del estudio fue caracterizar la epidemiologia de la dificultad respiratoria extrahospitalaria y los resultados subsiguientes de dichos pacientes. Metodologia Estudio de cohorte de base poblacional de adultos sin lesiones trasladados por SEM a uno de los 16 hospitales entre 2002 y 2006. Las historias clinicas del SEM se vincularon con los datos administrativos hospitalarios para las atenciones clasificadas por el personal de SEM con el diagnostico principal de “dificultad respiratoria”. Los autores describieron las caracteristicas del paciente y de la atencion extrahospitalaria, las intervenciones, los diagnosticos al alta hospitalarios (mediante codigos CIE-9), y los resultados del paciente. La asociacion entre las variables extrahospitalarias, definidas a priori, y el ingreso hospitalario se describio mediante un modelo de regresion logistica multivariable. Resultados Hubo 19.858 atenciones del SEM, de las cuales 166.908 fueron por dificultad respiratoria (11,9%, intervalo de confianza [IC] = 11,7% a 12,1%). La mitad de los pacientes fueron ingresados en el hospital (n = 9.964), de los cuales un tercio requirio cuidados intensivos (n = 3.094), y un 10% fallecieron previamente al alta (n = 948). Un 15% de los pacientes hospitalizados recibieron ventilacion mecanica invasiva (n = 1.501), de los cuales mas de la mitad fueron intubados durante la atencion extrahospitalaria (n = 896). Los diagnosticos principales al alta mas frecuentes entre los pacientes con dificultad respiratoria extrahospitalaria ingresados en el hospital fueron la insuficiencia cardiaca congestiva (16%), la neumonia (15%), la enfermedad pulmonar obstructiva cronica (13%) y la insuficiencia respiratoria aguda (13%). Pocos pacientes del SEM con dificultad respiratoria fueron catalogados con un diagnostico principal de infarto agudo de miocardio (3,5%, n = 350), o sometidos a una intervencion coronaria percutanea (0,7%, n = 71). En un modelo de regresion multivariable, las factores extrahospitalarios que se asociaron independientemente con el ingreso hospitalario incluyeron la frecuencia respiratoria inicial (odds ratio [OR] 1,29 por cada incremento de 5 respiraciones por minuto en la frecuencia respiratoria, IC 95% = 1,24 a 1,35), y la atencion en una residencia (OR 2,80, IC 95% = 2,28 a 3.43). Conclusiones En una cohorte de base poblacional, el personal de SEM halla frecuentemente dificultad respiratoria en los pacientes medicos, muchos de los cuales requieren ingreso hospitalario en la unidad de cuidados intensivos. Estos datos pueden ayudar a asesorar la terapia dirigida o las decisiones de triaje y traslado mas eficientes.