ARTICLES WE TALKED ABOUT THE MOST IN 2015
By Dr Hussain M. Alhashem and Dr Danya Khoujah
2015 has been filled with numerous research articles, updated guidelines, systematic reviews and meta-analyses, and choosing our “favourites” hasn’t been easy! Rather than going for the obvious (such as the updated American Heart Association (AHA) Guidelines – discussed on page 6), we tried to capture the most popular articles that are not quite so obvious, yet are relevant to our daily practice in the emergency department. Many websites and medical blogs have also created their own lists, such as Up To Date, Life in the Fast Lane, QxMD, and Academic Life in Emergency Medicine which served as inspiration for the following ten articles.
Managing Atrial Fibrillation
Clare L. Atzema, MD, MSc; Tyler W. Barrett, MD MSCI
Annals of Emergency Medicine, 2015 May; 65(5): 532-539
This paper was part of the Expert Clinical Management series for Annals of Emergency Medicine, a collection of shorter review articles relevant to daily clinical practice. This particular paper reviews updates about the care of atrial fibrillation from the past 4 years, including nine different guidelines published by American, Canadian and European professional groups.
This paper first addresses the management of the clearly unstable patient, defining instability as either decrease level of consciousness and/or severe hypotension, patients with acute heart failure or patients with acute myocardial infarction. The consensus is giving IV heparin immediately, followed by electrical cardioversion.
It then addresses the more challenging patient, who is conscious, hypotensive and with an unknown duration of atrial fibrillation. Ratecontrolling medications can potentiate the hypotension, as would a sedative given prior to electrical cardioversion, making it a difficult situation. The article proposes preparing for possible electrical cardioversion by putting cardioversion pads before proceeding with a trial of medical rate-control with either amiodarone, digoxin or diltiazem. Any further instability in vital signs should prompt immediate heparinization and electrical cardioversion. The medical provider should be prepared to intubate those patients if needed as well.
As for the stable patients, the treatment options are dependent on the time of onset. If atrial fibrillation started within less than 48 hours, patients can be treated with either rate- or rhythm- control, with no difference in outcome between the two. If the onset of symptoms is more than 48 hours or is unknown, rate-control is the only treatment option due to the risk of stroke.
For rate control, the article suggests targeting a goal resting pulse rate under 100 beats per minute, and discussed various medication options. Either beta blockers or calcium channel blockers, with no strong evidence for one choice over the other, as long as they are not combined. Digoxin is reserved as a second-line treatment due to its inability to control heart rate during exercise.
If electrical cardioversion is chosen, it may be prudent to avoid rate control medications prior to cardioversion, as one study suggests a decreased success rate with this practice. Pads are better placed anterior and posterior (“sandwich” method), with biphasic modes being superior to monophasic.
The decision to discharge patients on anticoagulation should be based on their stroke risk, the assessment of which is relatively similar across different guidelines, with an increased trend towards more anticoagulation over the past few years. One more commonly used coring system is CHA2DS2-VASc, with patients of a score of 2 or more receiving anticoagulants (As opposed to the older CHADS2 score, in which too many patients were categorized as moderate risk and were not necessarily given anticoagulants). The choice of warfarin versus a novel oral anticoagulant (NOAC) depends on various patient factors. However, NOACs should be avoided in patients with renal failure, mechanical heart valves, or significant mitral stenosis. Anticoagulation should also be offered to patients who are successfully cardioverted to sinus rhythm and meet criteria.
Bottom Line: Atrial fibrillation is a common (and frequently challenging) disease, and a quick review of current recommendations is prudent to provide patients with the best care possible.
Intravenous Subdissociative-Dose Ketamine Versus Morphine for Analgesia in the Emergency Department: A Randomized controlled trial
Sergey Motov, et al.
Annals of Emergency Medicine. September 2015; 66(3):222-229
This small prospective, randomized, double-blind trial compared subdissociative dose ketamine (0.1-0.6mg/kg) with morphine (0.1mg/kg) for control of moderate to severe abdominal, back, flank or musculoskeletal pain in adults. Both medications were equally effective in controlling pain at 15 and 30 minutes post-dose, with morphine achieving better pain control at 120 minutes. Fentanyl was available for both groups as a rescue medication, and was used significantly more frequently in the ketamine group at the 120-minute mark.
Side effects (although minor, such as dizziness, nausea, mood changes and disorientation) were more common in the ketamine group at 15 minutes, but not after that. Neither medications had a significant hemodynamic effect at any point.
Bottom Line: Ketamine should be considered as a safe, viable option for short-term management of moderate to severe pain in adults.
The Use of a Video Laryngoscope by Emergency Medicine Residents Is Associated With a Reduction in Esophageal Intubations in the Emergency Department
John C. Sakles, et al.
Academic Emergency Medicine, June 2015; 22(6):700-707
This study was a retrospective analysis of prospectively collected data after intubations at an academic center for 6 years, with a total of over 3,000 intubation attempts. Only intubations performed by residents were included in the study and data was collected about the method used, drugs administered, and any complications that occurred during intubation. The study primarily compared the incidence of esophageal intubation while using video laryngoscopes (VL) such as a GlideScope® or a C-MAC®, versus direct laryngoscopy (DL).
Residents using VL had a significantly lower incidence of esophageal intubations (1%) compared to those using DL (5.1%). Subsequently, the VL patient group had a lower incidence of hypoxemia, aspiration, dysrhythmia and hypotension, yet no different in cardiac arrest.
Bottom Line: VL appears to be a safer intubation method compared to DL when used by residents. This is probably related to the ability of more experienced physicians to provide real-time feedback for trainees in the setting of using a VL rather than innate properties of the VL itself.
Trial of Early Goal-Directed Resuscitation for Septic Shock a.k.a “ProMISe trial”
Paul R. Mouncey, et al.
The New England Journal of Medicine. 2015 April 2; 372(14):1301-1311
After the plethora of sepsis articles in 2014 comparing usual care with early goal directed therapy (EGDT), such as ARISE and ProCESS, comes one more nail in the coffin of EGDT. This multi-center, randomized, controlled trial was conducted in England, and included patients with presumed infections who met systemic inflammatory response syndrome (SIRS) criteria and were persistently
hypotensive despite one liter of IV fluids. All patients were given antibiotics then randomized to either a usual care group, receiving regular assessments and vital signs, or EGDT group, receiving algorithmic care for 6 hours with a provider present during the entire period.
The primary outcome, which was all-cause mortality at 90 days, was not significantly different between both groups, despite the EGDT group requiring more advanced cardiovascular support, a longer length of stay in the intensive care unit (ICU) and incurring higher costs.
Bottom Line: EGDT as we know it is on its way out. Early recognition and care, and having clear goals for management of patients in sepsis remain of utmost importance, but the strict adherence to EGDT guidelines does not seem to be necessary.
Andexanet Alfa for the Reversal of Factor Xa Inhibitor Activity
Deborah M. Siegal, et al.
New England Journal of Medicine; 2015 December; 373(25):2413-2424
With the increased use of Factor Xa inhibitors such as Apixaban and Rivaroxaban, finding a specific effective reversal agent has become a must. This randomized, double-blinded, placebo-controlled study examines the effectiveness of Andexanet as a reversal agent for Factor Xa inhibitors in older healthy volunteers. After taking the calculated doses of either Apixaban or Rivaroxaban to reach the maximum effect, volunteers were blinded to get either Andexanet or placebo. Andexanet was given as a loading dose, which in subgroups was followed by a 2-hour infusion, the doses of which varied between each group. The primary outcome was the percentage of change in anti-factor Xa activity, which was higher in the Andexanat group, indicating a
more rapid reduction in its activity. Secondary outcomes showed that all patients receiving the reversal agent had more than 80% reduction of anti-factor Xa activity, and their thrombin generation was restored within 2-5 minutes of administration. Calculated mean plasma concentration of unbound
Apixaban and Rivaroxaban was significantly lower in the Andexanat group. At the end of both bolus and infusion of Andexanet, unbound medication levels returned to a comparable level with the placebo group. No serious adverse effects were reported. Bottom Line: Andexanat appears to be a promising specific reversal agent for Factor Xa inhibitors, yet the evidence is rather limited regarding the optimal dosage and its true clinical effect.
Rocuronium versus succinylcholine for rapid sequence induction intubation
Diem T Tran, et al.
Cochrane Database Syst Rev, 2015 Oct; Vol. 10
An end has finally come to the never-ending debate of Succinylcholine versus Rocuronium for rapid sequence intubation (RSI).. or has it?
This Cochrane review attempts to answer this question, updating its 2008 review, and including a total of 50 controlled trials from 1966 to February 2015, with a total of 4151 participants. The primary outcome studied was testing excellent intubation conditions during RSI using Goldberg scale, which assigns specific scores to jaw relaxation during laryngoscopy and resistance to blade, vocal cord position, and patient’s response to intubation. The review concluded that there is moderate-quality evidence that succinylcholine is more likely than Rocuronium to produce excellent intubation conditions. That said, both drugs offer clinically acceptable conditions for intubation. An interesting finding as well is that the use of thiopental as an induction agent provides superior intubation conditions, and was used in over half of the participants, raising the possibility of a confounder, especially since newer studies from North America don’t utilize thiopental anymore due to its limited availability. Bottom Line: Succinylcholine remains equivalent to if not superior to Rocuronium.
An Age-Adjusted D-dimer Threshold for Emergency Department Patients With Suspected Pulmonary Embolus: Accuracy and Clinical Implications
Adam L. Sharp, et al.
Annals of Emergency Medicine. February 2016;67(2):249-257
Optimizing the diagnostic accuracy of pulmonary embolism has been a focus of the American College of Emergency Physicians’ (ACEP) Choosing Wisely initiative, and the use of age-adjusted cutoff for D-dimer was encouraged in the 2015 Best Practice Advice for Evaluation of Pulmonary Embolism from the American College of Physicians, but can this be safely applied to daily clinical practice? This retrospective study examined data collected from 14 emergency departments in patients above the age of 50 with suspected pulmonary embolism. Only those who received a d-dimer test were included, with a total of more than 30,000 patients. The primary goal was to test the compare the accuracy of age-adjusted d-dimer (age X 10 in patients above the age of 50) compared to the standard cut-off of 500 ng/dl. The study showed that age-adjusted d-dimer is less sensitive (92.9% compared to 98.0%), but more specific (63.9% compared to 54.4%), than a limit of 500 ng/dl, with a comparable negative predictive value (NPV) (99.8% vs 99.9%). Translated to the clinical setting, the use of age-adjusted cut-off will lead to 20% reduction in false positive values for d-dimer (and subsequent unnecessary imaging and contrast-associated complications). Bottom Line: Using age-adjusted d-dimer offers a higher specificity than a standard cut off of 500ng/dL, with a slight compromise in sensitivity, and a similar NPV.
The Diagnostic Accuracy of Bedside Ocular Ultrasonography for the Diagnosis of Retinal Detachment: A Systematic Review and Meta-Analysis
Michael E. Vrablik, et al.
Annals of Emergency Medicine. February 2015; 65(2):199-203
The increased availability of point-of-care ultrasound offers an attractive diagnostic tool for some ocular emergencies, namely retinal detachment. This systematic review identified 3 prospective observational trials to diagnose retinal detachment using an ultrasound in emergency departments, with a total of 201 patients. The prevalence of retinal detachment in the studies ranged between 15% and 38%, and included traumatic detachment. The sensitivity of the ultrasound studies was between 97% and 100%, with a specificity of 83% to 100%, using an ophthalmologic evaluation as gold standard. The higher sensitivities might be biased by the extensive training that some (not all) participants had, including fellowships.
Bottom Line: Bedside ocular ultrasound can be used to diagnose retinal detachment with a very high accuracy.
The Utility of Inferior Vena Cava Diameter and the Degree of Inspiratory Collapse in Patients With Systolic Heart Failure
Feyzullah Besli, et al.
American Journal of Emergency Medicine. May 2015;33(5):653-657
The relation between the diameter of the inferior vena cava (IVC), central venous pressure (CVP) and volume status has been extensively studied in the past to assess a patientfs fluid responsiveness, especially during resuscitations. This study builds on similar concepts to examine the correlation between elevated right atrial pressure in heart failure and IVC diameter and collapsibility. It compared 3 groups of patients; patients with decompensated heart failure, compensated heart failure and normal subjects. All patients had a transthoracic echo to assess their IVC diameter and degree of inspiratory collapse (.50%, <50% or absent), in addition to NTproBNP levels.
Both inferior vena cava diameters and NT-proBNP levels were higher in patients with heart failure than control subjects, with a strong association between IVC collapsibility and NT-proBNP values; the higher the NT-proBNP levels, the less collapsible the IVC. The study concluded that an IVC diameter of 20.5 mm or more, predicted a diagnosis of compensated heart failure with a sensitivity of 90% and a specificity of 73%.
Bottom Line: IVC measurement and collapsibility may be useful in determining a patient’s volume status in heart failure, in addition to other more commonly used sonographic markers.