Faculty Bibliography

BACKGROUND:Penetrating trauma patients in shock often require urgent operative intervention. Studies have demonstrated that variables obtained in the emergency department, such as lactate levels, can help the physician determine the presence of hemorrhagic shock, leading to more rapid intervention and improve prognosis in trauma patients. The purpose of the study is to determine if end-tidal (ET) CO2 correlates with serum lactate levels, a measure of tissue hypoxia and subsequently shock, in penetrating trauma patients. Secondarily, we sought to determine whether ET CO2 could be used to determine the patient's odds of requiring operative intervention. METHODS:A prospective observational cohort study was undertaken at an urban Level 1 trauma center. Baseline ET CO2 from nasal cannula and serum lactate level were recorded in all patients in whom the trauma team was activated. Outcomes defined were whether operative intervention was needed. Pearson correlation (R), correlation coefficient (r(2)), and odds ratio were calculated. RESULTS:One hundred five patients were enrolled. Pearson correlations and coefficients calculated for serum lactate level to ET CO2 were R = -0.86 (r(2) = 0.74, p < 0.0001). Of patients requiring operative intervention, 81.97% had abnormally low ET CO2 and 54.1% had abnormally high serum lactate levels. Odds ratios of patients needing an emergent operation with abnormally low ET CO2 was 20.4 (95% confidence interval, 7.47-55.96) and with abnormally high serum lactate levels was 4 (95% confidence interval, 1.68-5.93). CONCLUSION/CONCLUSIONS:ET CO2 has a strong inverse correlation to serum lactate levels. Abnormally low ET CO2 values were associated with greater increased odds compared with serum lactate levels of penetrating trauma patients requiring operative intervention. LEVEL OF EVIDENCE/METHODS:Prognostic/diagnostic study, level I.

Posterior reversible encephalopathy syndrome (PRES) is a central nervous system pathology characterized by headaches, altered mental status, seizures, and visual loss. The syndrome is a clincoradiologic diagnosis, which mandates neuroimaging. The aim of this study is to describe a case of asymptomatic PRES in which the only sign was incidental papilledema found on ophthalmologic examination. A thin 19-year-old female G1P1 s/p natural spontaneous vaginal delivery was referred to our emergency department (ED) by the ophthalmology clinic after finding bilateral papilledema on fundoscopic examination. She denied any fevers, chills, nausea, vomiting, as well as headache, lightheadedness, visual changes, or blurriness. Lumbar puncture was performed, and opening pressure was found to be greater than 55 cmH2O. After collecting Cerebrospinal fluid (CSF) for routine analysis, approximately 15 to 20 mL of CSF was drained. After several revisits to the ED, the neurology clinic was consulted. The magnetic resonance imaging ordered by the neurology clinic, as read by the radiologist, showed a focal lesion in splenium of the corpus callosum and diffusion restriction suggestive of acute infarction (although the anatomical location and age would be unusual). This is an atypical manifestation of PRES. The myriad of clinical symptoms and presentations of PRES has become more identifiable as more case reports of the syndrome are published. This case demonstrates that this atypical syndrome may present in an atypical way. The patient may be asymptomatic, and although imaging defines the diagnosis, a complete physical examination must not be ignored because the only sign may be papilledema.