|Pediatric Emergency Medicine|
BACKGROUND: People with supraventricular tachycardia (SVT) frequently are symptomatic and present to the emergency department for treatment. Although vagal manoeuvres may terminate SVT, they often fail, and subsequently adenosine or calcium channel antagonists (CCAs) are administered. Both are known to be effective, but both have a significant side effect profile. This is an update of a Cochrane review previously published in 2006.
OBJECTIVES: To review all randomised controlled trials (RCTs) that compare effects of adenosine versus CCAs in terminating SVT.
SEARCH METHODS: We identified studies by searching CENTRAL, MEDLINE, Embase, and two trial registers in July 2017. We checked bibliographies of identified studies and applied no language restrictions.
SELECTION CRITERIA: We planned to include all RCTs that compare adenosine versus a CCA for patients of any age presenting with SVT.
DATA COLLECTION AND ANALYSIS: We used standard methodological procedures as expected by Cochrane. Two review authors independently checked results of searches to identify relevant studies and resolved differences by discussion with a third review author. At least two review authors independently assessed each included study and extracted study data. We entered extracted data into Review Manager 5. Primary outcomes were rate of reversion to sinus rhythm and major adverse effects of adenosine and CCAs. Secondary outcomes were rate of recurrence, time to reversion, and minor adverse outcomes. We measured outcomes by calculating odds ratios (ORs) and assessed the quality of primary outcomes using the GRADE approach through the GRADEproGDT website.
MAIN RESULTS: We identified two new studies for inclusion in the review update; the review now includes seven trials with 622 participants who presented to an emergency department with SVT. All included studies were RCTs, but only three described the randomisation process, and none had blinded participants, personnel, or outcome assessors to the intervention given. Moderate-quality evidence shows no differences in the number of people reverting to sinus rhythm who were treated with adenosine or CCA (89.7% vs 92.9%; OR 1.51, 95% confidence interval (CI) 0.85 to 2.68; participants = 622; studies = 7; I(2) = 36%). Low-quality evidence suggests no appreciable differences in major adverse event rates between CCAs and adenosine. Researchers reported only one case of hypotension in the CCA group and none in the adenosine group (0.66% vs 0%; OR 3.09, 95% CI 0.12 to 76.71; participants = 306; studies = 3; I(2) = 0%). Included trials did not report length of stay in hospital nor patient satisfaction.
AUTHORS' CONCLUSIONS: Moderate-quality evidence shows no differences in effects of adenosine and calcium channel antagonists for treatment of SVT on reverting to sinus rhythm, and low-quality evidence suggests no appreciable differences in the incidence of hypotension. A study comparing patient experiences and prospectively studied adverse events would provide evidence on which treatment is preferable for management of SVT.
As an emergency medicine physician, I find the review insightful in the sense that it provides validation of practice with either medication, with no significant superiority or inferiority demonstrated. Further studies are needed.
This is an updated review of comparison of CCB and Adenosine in treating SVT. Verapamil was used in most of the studies. The literature is only of moderate quality, but confirmed that there was no advantage of one agent over the other. Side effects were also comparable; although, the data is less reliable for this metric.
There is no explicit mention of age group of patients studied making, thus it difficult to know if the results apply to children. Also Calcium channel blockers are a diverse group of medications; it would be useful to know if one or any of them can be used effectively for this indication.
I'm not sure why this is categorized under pediatric EM since 6/7 included studies involved adults. While the review is well-done, because of lack of data in the included studies, it can't tell us about the things I'd really like to know about clinically: adverse events (a typical problem in systematic reviews), and patient satisfaction, which is one area where anecdotally, calcium channel blockers seem to be the winner.