568 Abstracts

PtCO2 increased by 5.0 mm Hg (95% confidence interval [CI]3.1–6.8, P < 0.001) with oxygen compared to room air. Minuteventilation decreased by 1.4 L/min (95%CI 0.11–2.6 L/min; p <0.03), and volume-of-dead-space-to-tidal-volume ratio in-creased by 0.067 (95% CI 0.035–0.1; p < 0.001), with oxygencompared to room air. This study demonstrated that breathing100% oxygen worsens hypercapnia in stable patients with OAH.

[Kristy Rahimi, MD

Denver Health Medical Center Denver, CO]

Comments: This study raises the important concern that theadministration of oxygen may have unintended deleterious con-sequences in patients with OAH. That said, although the labora-tory assessment of pCO2 was found to increase, it was unclear ifthis translated to any important clinical outcomes or if it wouldin an emergent situation. Nonetheless, this is another clinical ex-ample of how oxygen in certain settings can increase dead spaceand contribute to the development of hypercapnia. The emer-gency physician should be mindful of the concern.

, ACUTE ISCHEMIC STROKE IN CHILDREN VER-SUS YOUNGADULTS.Bigi S, Fischer U,Wehrli E, et al. AnnNeurol 2011;70:245–54.

This study from Switzerland compared 128 children (ages 1month to 16 years) to 199 young adults (ages 16-45 years) whosuffered an acute ischemic stroke from January 2000 to Decem-ber 2008. Data for children were collected from the Swiss NeuroPediatric Stroke Registry (a Swiss national registry) and data foryoung adults were collected from the Bernese stroke registry (ahospital-based registry). Children were more likely to be male(62% vs. 49%, p = 0.023) and had fewer risk factors such as hy-pertension (p = 0.001), hypercholesterolemia (p = 0.003), ora family history of stroke (p = 0.048). Stroke etiology in childrenwas more likely to be ‘‘other determined cause’’ (51% vs. 29%,p < 0.001), steno-occlusive arteriopathy (18% vs. 0%, p <0.001), and moyamoya syndrome (5% vs. 0.2%, p = 0.007).Stroke etiology in young adults was more likely to be cervico-cerebral artery dissections (23% vs. 13%, p = 0.005) or cardi-oembolic (37% vs. 17%, p < 0.001). Initial stroke severitygraded using the pediatric version of the National Institutes ofHealth Stroke Scale (PedNIHSS) for children and NIHSS foryoung adults was similar in both groups. There was also no dif-ference in outcome at 3 and 6 months as determined by a mod-ified Rankin scale score. Mortality rates were similar as well(4% in children and 6% in young adults, p = 0.436). Whereas6 of 8 young adults died due to their stroke, 3 of 8 childrendied due to the underlying disease that provoked the stroke. Alow PedNIHSS or NIHSS score was the most important predic-tor of favorable outcome in both groups (p < 0.001).

[Omeed Saghafi, MD

Denver Health Medical Center Denver, CO]

Comment: This study has the limitations inherent to a retro-spective analysis, and is further limited by several other factors.The registries used may not be comparable to other registries orone another, assessment of stroke severity in children ismore dif-ficult and lesswell validated than in young adults, and the recom-mended diagnosticwork-up in children andyoung adults differed

(young adults were more likely to receive transesophageal echo-cardiograms, which were better at diagnosing a cardioembolicorigin for stroke, and young adults were less likely to be screenedfor coagulopathies). Still, this study is valuable in that it suggestsa difference in stroke etiology but no difference in severity, mor-tality, or outcome between children and young adults.

, REDUCING TIME-TO-TREATMENT DECREASESMORTALITY OF TRAUMA PATIENTS WITH ACUTESUBDURAL HEMATOMA. Tien HC, Jung V, Pinto R,Mainprize T, Scales DC, Rizoli SB. Ann Surg 2011;253:1178–83.

The ‘‘golden hour’’ in the treatment of the trauma patient isa well-known concept suggesting that early assessment andtreatment of a trauma patient will maximize the likelihood ofsurvival. Although often cited in textbooks and widely taughtwithin the classroom, there are few objective data demonstratingthat the early treatment of the trauma patient results in improvedoutcomes. This retrospective cohort study from a single large ur-ban Canadian trauma center attempted to determine if there wasa survival benefit with reduced pre-hospital time and time to cra-niotomy in patients sustaining isolated acute subdural hemato-mas. Excluding patients referred from outside hospitals, thosewith penetrating trauma, severe torso injury, and intoxication,the final study population of patients who underwent craniot-omy consisted of 149 patients divided into two groups basedupon their time from injury to first incision, either > or < 4 h.Patients who arrived from the scene of an accident to the emer-gency department (ED) in < 1 h had a decreased mortality ratecompared to patients arriving after an hour (< 1 h 37%mortality,> 1 h 53% mortality), although in a univariate analysis this wasnot statistically significant (p = 0.09). There was also no statis-tical difference in mortality between patients who had early cra-niotomy (< 4 h from time of arrival to time of craniotomy = 42%vs. > 4 h from time of arrival to time of craniotomy = 36%). Ina multivariate analysis, which included the severity of intracere-bral hematoma and herniation demonstrated on computed to-mography, the authors found an association between mortalityand increased age (odds ratio [OR] 1.04; 95% confidence inter-val [CI] 1.02–1.07, p = 0.004), initial on-scene Glasgow ComaScale score (OR 0.78; 95% CI 0.69–0.88, p < 0.001), andincreased pre-hospital time (OR 1.03; 95% CI 1.004–1.06,p = 0.024), but no association between time from the ED tothe operating room (OR 0.995; 95% CI 0.99–1.0, p = 0.056).The authors concluded that the rapid pre-hospital transport ofpatients to the ED is associated with decreased mortality.

[Austin Johnson, MD

Denver Health Medical Center Denver, CO]

Comment:The rule of the ‘‘golden hour’’ has been amainstayin basic trauma care for years. This article demonstrates that therapid transport of isolated subdural hematomas to a trauma cen-ter by emergency medical services results in increased overallsurvival. Unfortunately, the non-blinded bias of the time fromED to operating room, which is likely to be shortest in the pa-tients with the worst disease severity, makes it difficult to deter-mine if rapid surgical decompression of subdural hematomasleads to improved outcomes.