Metabolic vs structural coma in the ED--an observational study.
BACKGROUND
Patients presenting unconscious may reasonably be categorized as suffering from a metabolic or structural condition.


OBJECTIVE
The objective was to investigate if some routinely recorded clinical features may help to distinguish between these 2 main forms of coma in the emergency department (ED).


METHODS
Adults admitted to an ED in Stockholm between February 2003 and May 2005 with a Glasgow Coma Scale (GCS) score less than 11 were enrolled prospectively. The GCS score was entered into a protocol that was complemented with available data within 1 month.


RESULTS
The study population of 875 patients was classified into 2 main groups: one with a metabolic (n = 633; 72%) and one with a structural disorder (n = 242; 28%). Among the clinical features recorded in the ED, 3 were found to be strongly associated with a metabolic disorder, namely, young age, low or normal blood pressure, and absence of focal signs in the neurological examination. Patients younger than 51 years with a systolic blood pressure less than 151 mm Hg who did not display signs of focal pathology had a probability of 96% for having a metabolic coma. The mean GCS score on admission was identical in the groups. Hospital mortality was 14% in the metabolic and 56% in the structural group.


CONCLUSIONS
These findings indicate that unconscious young adults who present without a traumatic incident with a low or normal blood pressure and without signs of focal pathology most probably suffer from a metabolic disorder, wherefore computed tomography of the brain may be postponed and often avoided.
Medical Intensive Care Unit, South Hospital, SE-118 83 Stockholm, Sweden.
Sune
S
Forsberg
Jonas
J
Höjer
Ulf
U
Ludwigs
Harriet
H
Nyström
D000367:Age Factors; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D003128:Coma / Q000145:classification / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D004636:Emergency Service, Hospital; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D008297:Male; D008659:Metabolic Diseases / Q000150:complications / Q000175:diagnosis; D008875:Middle Aged; D011446:Prospective Studies; D012737:Sex Factors