2012 - August R3 Journal Review
Hoffmann U, Truong QA, Schoenfeld DA et al. Coronary CT Angiography versus Standard Evaluation in Acute Chest Pain. N Engl J Med 2012 Jun 26;367:299-308 This was a multicenter, randomized, controlled trial of patients presenting to the ED with chest pain within 24 hours that lasted >5 min and were in sinus rhythm. They were randomized to either standard chest pain workup (to include whatever the current provider deemed necessary) versus having Coronary CT angiography(CCTA) performed. Patient's were excluded if they had known CAD, new ischemic ECG changes, elevated troponin, creatinine >1.5 mg/dl, were hemodynamically unstable, had iodine allergy, BMI >40 or currently symptomatic asthma. They were followed up with a 72 hour and 28 day telephone call.
1000 patients underwent randomization, 501 to CCTA and 499 to standard workup; the groups were well matched. The primary outcome of length of hospital stay(LOS) was statistically significant with mean LOS of CCTA group of 23.2 hours and standard workup group 30.8 hours for a decrease in LOS by about 8 hours. Secondary outcomes included time to diagnosis, which was equally shortened by about 8 hours and the % discharged from the ED, which for the CCTA group was 47% and standard workup group 12%. Additional secondary outcomes included safety variables – they found two periprocedural complications in the CCTA group, one case of perioperative bleeding after cardiothoracic surgery for an identified anomalous coronary artery and one case of transient increase in the creatinine level after CCTA without the need for dialysis in a patient with a urethral stone and hydronephrosis. Neither group had any patients with undetected ACS but there were 8 patients with adverse cardiovascular event during follow up, 6 in standard evaluation group(4 MI, 2 unstable angina requiring PCI) and 2 patients in CCTA group (1 MI, 1 unstable angina requiring PCI). Both adverse events in CCTA group had significant CAD seen on CCTA but were initially medically managed. Radiation exposure was higher in CCTA group (14.3 mSv/patient) than standard evaluation group(5.3 mSv/patient). Costs for each group were similar.
This study shows that CCTA is a faster risk stratification test than our standard workup. It suggests that utilization of CCTA will not miss more ACS than standard workup (no missed cases in either group). Most likely this study, along with the NEJM study published March 26, 2012, will pave the way for higher CCTA utilization in the future. The limitations of this study included lack of blinding of practitioners possibly leading to faster discharge times. The study is fairly generalizable to the average population given the presented demographics, however, a 64 slice CT was required which some smaller EDs may not have access to. They did not include patients younger than 40 or older than 74. Higher rates of radiation exposure will certainly be seen with higher utilization of CCTA. This is certainly a limitation of more use but some proponents of CCTA argue that no prospective study has ever shown that CT increases risk of cancer in adults.
Costantino TG, Satz WA, Dehnkamp W, and Goett H. Randomized Trial Comparing Intraoral Ultrasound to Landmark-based Needle Aspiration in Patients with Suspected Peritonsillar Abscess. Acad Emerg Med. 2012; (6):626-31 This prospective, randomized, controlled clinic trial compared intraoral US to diagnosed and guide drainage of a PTA vs. traditional landmark-based methods of inspection and needle aspiration by EPs. Secondary objectives included successful aspiration of pus from the PTA, the use of CT scans, and ENT consultation rates in each arm.
The study included a convenience sample of hemodyndamically stable adult patients who presented with a constellation of signs and symptoms that treating physicians felt represented a PTA and that they were prepared to perform needle aspiration on. who presented to a single, large, urban university hospital over a two year period. Pt’s were randomized using an internet-based program with a concealed allocation schedule.
A total of 28 patients were enrolled; 14 in each arm (ultrasound [US] vs. Land Mark [LM]). Group characteristics were well matched in respect of age, sex, ED LOS. The primary outcome measure of diagnostic accuracy found US to be 100% accurate vs. 64% in the LM arm. In terms of secondary outcome measures, US led to more successful aspiration of purulent material then LM, lower ENT consult rate (7% vs. 50%), and lower rates of CT scanning (0% vs. 35%). There was only one immediate complication in the US group in which a pt turned cyanotic from methemoglobin following topical anesthetic spray. Both US and LM arms had one pt return at 2 day follow up with a worsening abscess, both of which had had successful aspiration during the initial visit. The study concluded that intraoral US can reliably diagnoses peritonsillar cellulitis and peritonsillar abscess, as well as, allow for greater success with aspiration then tradition LM techniques. Limitations of this study include the following: pts represented a convenience sample, enrollment only occurred when study authors were present, procedures were performed by residents who may be more adept with US then EPs practicing out in the community, and small size of study. Lastly using clinical judgment as the standard for the final diagnosis on the follow up visit instead of CT could have led to an overstatement of occurrence of PTC, as small abscess not seen on US may have resolved with antibiotic treatment.
The Italian Cooling Experience Study Group. Early- versus late-initiation of therapeutic hypothermia after cardiac arrest: Preliminary observations from the experience of 17 Italian intensive care units. Resuscitation. July 2012;83(7):823-828. Mild therapeutic hypothermia (TH) has been shown to be beneficial in improving neurologic outcomes in adult cardiac arrest. However, optimal timing of institution of TH is not known. This observation prospective multicenter (17 site) study by the Italian Cooling Experience study group (ICE) attempted to determine the relationship between timing of institution of TH and mortality and neurologic outcome. 174 patients admitted to one of the 17 center ICUs after cardiac arrest were included other than those below 18 years of age, those with severe hemodynamic instability (SBP<80 despite vasoactive medications), sustained cardiac arrhythmias, severe coagulopathy with active bleeding (need for transfusion >2 PRBCs per day), traumatic arrest, pregnancy, acute intoxication.
70.1% and all those in 8/17 centers received TH. TH was started at median times of 60 and 191.5 min in the early and late groups respectively. Mortality in the ICU was 47.4% and 23.8% for the early and late TH groups respectively (p = 0.01). This was consistent with six-month mortality rates of 60.8% and 40.5% for early and late TH groups (p = 0.04). Neurologic outcomes as determined by cerebral performance category (CPC) showed not difference in neurologic outcomes between survivors in either group.
Limitations of this study are that no standardized hypothermia protocol was used (institution dependent). However, the stated goal temperatures cited in the study are in keeping with typical protocol. Patients were not randomized (decision to do TH left to treating physician) to either treatment group. However, SAPS II scores for early and late TH patients were 64 and 56 respectively (p = 0.03) indicating those in the early group were predicted to have a higher mortality at baseline, which was consistent with the study’s outcomes. Additionally, the early TH group had significantly lower BPs over the first 2 days and a trend towards need for more vasopressors. Authors also note in their discussion that were lactate levels were available, they were higher in the early TH group and lactate levels after ROSC and early clearance has been correlated with outcomes. This likely demonstrates that patients in the early TH were sicker and thus more likely to have poor outcomes irrespective of the time of initiation to therapy. Furthermore, it is possible that there was more urgency on part of the treating physicians to cool the patients as they were predicted to be at higher risk for poor outcomes, thus placing them in the early TH group.
As the time cut off for “early” and “late” hypothermia treatment was arbitrarily decided to be 2 hrs, it is hard to know the clinical significance of this study’s results in the context of these disparities in illness severity between groups. These results would be much more provocative had this been an RCT or even had group demographics and indications of clinical severity been similar. Treatment group differences might have been minimized with a larger study population. Also, it is important to note that a 100% of patients at a number of participating institutions received TH, leaving one to question the disparity in practice patterns amongst participating centers. While this study does suggest an interesting possible connection between timing of TH and mortality, this is an area clearly in need of further investigation and not likely to influence emergency practice for the time being. This research does however support previous findings that survivors of cardiac arrest who have undergone TH can survive with good neurologic recovery.