Risk of hypotension during apnea testing.

OBJECTIVE: To determine the safety of apnea testing. DESIGN: Prospective, consecutive study. SETTING: Inner-city trauma center. PATIENTS: A total of 70 apnea tests were performed on 61 comatose patients as part of the determination of brain death. RESULTS: Only 43 examinations (61%) were well tolerated. During 27 examinations (39%) patients either developed marked hypotension (> or = 15% drop in mean arterial pressure) (n = 23) or required prophylactic vasopressor manipulation (n = 4). Of the 27 examinations in which hypotension developed, 14 were aborted, two were tolerated despite marked hypotension, four were tolerated after administration of prophylactic epinephrine (n = 1) or dopamine hydrochloride (n = 3), and seven were successfully completed after increases in the rate of dopamine infusion during the test. CONCLUSIONS: Hypotension can pose a significant risk to patients undergoing apnea testing. Constant monitoring of vital signs throughout the test is essential to its safe completion.

Clinical predictors of abnormality disclosed by computed tomography after mild head trauma.

We prospectively studied 712 consecutive patients during a 1-year period who presented with amnesia or loss of consciousness after nonpenetrating head trauma and who had a perfect Glasgow Coma Scale score of 15. Of the 67 (9.4%) patients with acute traumatic lesions disclosed by computed tomography (CT) of the head, 2 required neurosurgical intervention and 1 died. Four factors were statistically correlated (P < 0.05) with abnormal CT findings: Older age, white race, signs of basilar skull fracture, and being either a pedestrian hit by a motor vehicle or a victim of an assault. Sex, length of antero- or retrograde amnesia, forward and reverse digit spans, object recall, focal abnormality on the general neurological exam, and subjective complaints were not statistically correlated with CT abnormality. Using step-wise discriminant function analysis, no single item or combination of items could be used to classify 95% of the patients into either the normal or abnormal CT group. Therefore, regardless of age, mechanism of injury, or clinical findings, intracranial lesions cannot be completely excluded clinically on head-trauma patients who have loss of consciousness or amnesia, even if the Glasgow Coma Scale score is 15. However, only two patients (0.3%) required neurosurgical intervention.

Clinicopathological findings associated with agenesis of the corpus callosum.

Seven hundred five cases of agenesis of the corpus callosum (ACC) are reviewed from the literature (n = 660) and from our own observations (n = 45). The diagnosis was made or confirmed using neuroradiological techniques (n = 519) and necropsy or surgery (n = 231). Association with abnormalities often of chromosomes 8, 11, 13-15 and 18 suggests their involvement in abnormal corpus callosum (CC) morphogenesis. Four syndromes (e.g. Aicardi, acrocallosal, Andermann and Shapiro) are characterized by ACC, while others are only sporadically associated (e.g. fetal alcohol syndrome, Dandy-Walker syndrome, Leigh disease, Arnold-Chiari II syndrome). In non-Aicardi patients, the male-to-female ratio was 3:2 and X-linked recessive inheritance is postulated to play a role in some cases. Common abnormalities in acallosal patients included: mental retardation (MR), 73% [corrected]; seizures, 42%; ocular anomalies, 42%; gyral abnormalities, 32%; hydrocephalus, 23%; other central nervous system (CNS) lesions, 29%; costovertebral defects, 24%. Developmental disabilities are not attributable to absence of the CC per se, but due to other CNS malformation or dysfunction, which may be genetic or non-genetic. Future research using recombinant DNA techniques will enable isolation and identification of specific chromosomal defects in those cases with a genetic abnormality.