The etiology and outcome of non-traumatic coma in critical care: a systematic review

Abstract

BackgroundNon-traumatic coma (NTC) is a serious condition requiring swift medical or surgical decision making upon arrival at the emergency department. Knowledge of the most frequent etiologies of NTC and associated mortality might improve the management of these patients. Here, we present the results of a systematic literature search on the etiologies and prognosis of NTC.MethodsTwo reviewers independently performed a systematic literature search in the Pubmed, Embase and Cochrane databases with subsequent reference and citation checking. Inclusion criteria were retrospective or prospective observational studies on NTC, which reported on etiologies and prognostic information of patients admitted to the emergency department or intensive care unit.ResultsEventually, 14 studies with enough data on NTC, were selected for this systematic literature review. The most common causes of NTC were stroke (6-54%), post-anoxic coma (3-42%), poisoning (<1-39%) and metabolic causes (1-29%). NTC was also often caused by infections, especially in African studies affecting 10-51% of patients. The NTC mortality rate ranged from 25 to 87% and the mortality rate continued to increase long after the event had occurred. Also, 5-25% of patients remained moderately-severely disabled or in permanent vegetative state. The mortality was highest for stroke (60-95%) and post-anoxic coma (54-89%) and lowest for poisoning (0-39%) and epilepsy (0-10%).ConclusionNTC represents a challenge to the emergency and the critical care physicians with an important mortality and moderate-severe disability rate. Even though, included studies were very heterogeneous, the most common causes of NTC are stroke, post anoxic, poisoning and various metabolic etiologies. The best outcome is achieved for patients with poisoning and epilepsy, while the worst outcome was seen in patients with stroke and post-anoxic coma. Adequate knowledge of the most common causes of NTC and prioritizing the causes by mortality ensures a swift and adequate work-up in diagnosis of NTC and may improve outcome.Electronic supplementary materialThe online version of this article (doi:10.1186/s12871-015-0041-9) contains supplementary material, which is available to authorized users.

Alteración del estado de conciencia en el paciente intoxicado

“…Dentro de todo este manejo es necesario garantizar medidas de protección al personal de salud, si se sospecha una etiología tóxica y hay materiales peligrosos que tienen absorción por piel y mucosas que ponen en riesgo al personal [24][25][26] . Es fundamental un interrogatorio preciso a familiares, testigos y personal de atención pre hospitalaria, indagar sobre el tiempo de inicio de los síntomas para establecer si es un cuadro agudo o crónico, objetos encontrados en la escena como agujas, blíster incompletos, olores extraños, historia de eventos similares, comorbilidades específicamente psiquiátricas, uso de psicofármacos, drogas de abuso, cambios en las prescripciones para establecer interacciones medicamenla etiología tóxica en cuadros súbitos, presencia de un nexo epidemiológico, antecedente de exposición, manifestaciones clínicas compatibles con toxidrome y ausencia de signos neurológicos focales 18,19 . En una revisión sistemática de la literatura sobre la etiología y desenlace de pacientes en coma no traumático entre 1981 y 2013, se observó que la principal causa eran los eventos isquémicos cerebrales, seguido de estados post anoxia y en tercer lugar por las causas tóxicas (prevalencia entre 1% y 39%).…”

“…La mortalidad secundaria al coma de origen tóxico fue del 2.4%. Este último grupo tenía probabilidad de recuperación más rápida una vez pasaba la vida media del xenobiótico, sin mayores secuelas neurológicas 18 .…”

A systematic approach to the unconscious patient

“…14 Non-traumatic unconscious patients presenting with a stroke have the highest mortality, while those presenting with epilepsy and poisoning have the best prognosis. 14,16,17 A Swedish study of coma patients presenting to the Emergency Department found initial inpatient mortality to be 27%, rising to 39% at 1 year. 18 Patients with a lower GCS at presentation, 3-5, have a significantly higher mortality than those with a GCS of 7-10.…”

“…Unconscious patients with an acute neurological condition should be discussed with either a neurosurgeon, neurologist or stroke physician to determine further management. 4,14 Concussion results in neurological signs and symptoms following a force injury to the brain, which may be minor, with the absence of macroscopic neural damage. 15 Specific treatment depends on the underlying aetiology of the coma.…”

“…In patients who remain physiologically unstable or where the cause of coma is not immediately clear or reversible, help from critical care colleagues must be sought at a very early stage. 4,5,14 If raised intracranial pressure is suspected the patient should be managed in a 30° head tilt position. Unconscious patients with an acute neurological condition should be discussed with either a neurosurgeon, neurologist or stroke physician to determine further management.…”