The Journal of Emergency Medicine 1209

maximal, and average ETCO2 number for the initial 15 min dur-ing advance life support (ALS) or until return of spontaneouscirculation (ROSC). Capnography was significantly higher onpatients that regained ROSC when compared to those withoutit for any initial rhythm and cause of the arrest (p < 0.001).ETCO2 levels were also significantly higher with respiratorycause of arrest when compared to primary cardiac causes. Thelowest ETCO2 were observed when cardiac arrest resultedfrom pulmonary embolism. Another factor found to influenceETCO2 included initiation of CPR by bystander and the timeof recording after the arrest, the earlier the initiation of CPRby bystander and the earlier the monitoring after arrest, thehigher the ETCO2 levels. The authors concluded that severalfactors complicate the interpretation of ETCO2 during ALS,and no clear cut-off value can be determined whether ROSCwas achieved or not. Previous clinical studies have shown thatETCO2 > 2.4 kPa after 20 min has been shown to predictROSC, and values < 1.3 kPa have been associated with noROSC. The authors warned of the importance of not using strictcut-off values that could mistakenly lead to premature treatmentwithdrawal. Major limitations included the fact that anesthesiol-ogists recorded numbers manually, patients were manually ven-tilated, and epinephrine use was not recorded.

[Sabrina Adams, MD

Denver Health Medical Center, Denver, CO]

Comments: This study raised an important point when itcomes to the interpretation of ETCO2 values during ALS be-cause so many confounding factors play a role. Quality of chestcompressions directly impact ETCO2 numbers and should stillbe used to encourage rescuers to maximize their quality ofCPR.

, EFFECTS OF FLUID RESUSCITATION WITH SYN-THETIC COLLOIDS OR CRYSTALLOIDS ALONE ONSHOCK REVERSAL, FLUID BALANCE, AND PATIENTOUTCOMES IN PATIENTS WITH SEVERE SEPSIS: APROSPECTIVE SEQUENTIAL ANALYSIS. Bayer O,Reinhart K, Khol M, et al. Crit Care Med 2012;40:2543–51.

The best choice of asanguineous fluid to use during severesepsis is still controversial. Some data suggest that the use ofcolloids can improve cardiac performance and were associatedwith lower resuscitation volumewhen compared to crystalloids.This prospective study from Germany assessed shock reversaland required fluid volumes in 1046 patients that presented tothe surgical intensive care unit (ICU) with septic shock overa period of 6 years. Three fluid therapies were used, including6% hydroxyethyl starch (HES), n = 360; 4% gelatin, n = 352;and crystalloids alone, n = 334. Time to shock reversal was de-fined as serum lactate < 2.2 mmol/L or discontinuation of vaso-pressors, and considered the main outcome for the study.Hemodynamic goals included mean arterial blood pressure> 70 mm Hg, central venous pressure > 8, and central venousoxygen saturation > 70%. And safety outcomes included acutekidney injury (AKI) and new need for renal replacement therapy(RRT). There was no significant difference among the threefluid therapies regarding time to shock reversal. More fluidswere needed over the first 4 days to achieve hemodynamic goals

in the crystalloid-alone group (fluid ratios 1.4:1 [crystalloid toHES] and 1.1:1 [crystalloid to gelatin]). However, after day 5,total fluid balance was more negative in the crystalloid groupwhen compared to the other groups. HES and gelatin fluidsuse were independent risk factors for AKI (odds ratio, 95% con-fidence interval: 2.55, 1.76–3.69 and 1.85, 1.31–2.62, respec-tively). It was also noted that patients who received syntheticcolloids received more allogenic blood products when com-pared to crystalloids. Severity scores, hospital length of stay,and ICU or hospital mortality were similar among all groups.Patients in both colloid groups, significantly, spent longer pe-riods of time on the ventilator and had longer ICU lengths ofstay. The authors concluded that shock reversal does not occurfaster when using colloids and there is no fluid saving when us-ing colloids vs. crystalloids alone. The study also showed thatcolloids are not completely safe and lead to a higher numberof renal impairment and higher RRT use. Limitations includeits single-center design and randomization.

[Sabrina Adams, MD

Denver Health Medical Center, Denver, CO]

Comments: New HES clinical trials are currently ongoing incritically ill or septic patients. This study showed important datawhen it comes to fluid selection. Given that crystalloids havesignificantly lower cost and are associated with less complica-tions, at least until more research is done, it should be the fluidof choice when resuscitating septic patients.

, INCREMENTAL PROGNOSTIC VALUE OF DIFFER-ENT COMPONENTS OF CORONARY ATHEROSCLE-ROTIC PLAQUE AT CARDIAC CT ANGIOGRAPHYBEYOND CORONARY CALCIFICATION IN PATIENTSWITH ACUTE CHEST PAIN. Nance JW Jr, Schlett CL,Schoepf UJ, et al. Radiology 2012;264:679–90.

In this single-centered, retrospective cohort study of 458low-to-intermediate-risk patients presenting with acute onsetchest pain and without acute coronary syndrome or non-cardiacetiology of their symptoms on initial work-up, the authors inves-tigated the value of coronary artery calcium (CAC) score andcardiac computed tomography (CT) angiography in predictingthe risk for major adverse coronary events (MACE). Of the458 patients included in the analysis, 70 (15%) had a MACEduring the 24-month follow-up period. Here MACEwas definedby cardiac death (due to myocardial infarction, heart failure, ordysrhythmia), non-fatal myocardial infarction, unstable angina,or need for revascularization procedure (coronary artery bypassgraft or percutaneous coronary intervention). In patients withoutatherosclerotic plaque seen on CT angiography, there were zeroadverse events. Among patients with CAC scores of zero, 5%experienced adverse cardiac events. Among patients withoutcoronary artery stenosis on CT angiography, 10% experienceda MACE. One hundred percent of patients with MACE had ath-erosclerotic plaques by CT angiography, whereas 59% of pa-tients without MACE had atherosclerotic plaques. Of patientswith MACE and atherosclerotic plaque, 74% demonstratedmixed calcified and non-calcified disease, whereas exclusivelycalcified and exclusively non-calcified plaques represent 9%and 17% of atherosclerotic disease associated with MACE.