This month’s articles are a little special. Usually, I pick out the articles that catch my eye, but it’s easy to imagine that my biases filter out a lot of interesting medical literature. As there were a number of experts descending on Berlin this month for SMACC, Casey Parker and I invited a few people to suggest a paper and discuss it with us over a beer for our podcast. The conversation was great, and can be found here. These are the articles that were picked:
A monthly collection of the most interesting emergency medical literature I have encountered.
Its that time again. Here are my favorite medical reads of the last month – well, actually, last 2 months. There are some really good papers in this edition. I hope you enjoy…
1 good ECG begets another
Riley RF, Newby LK, Don CW, et al. Diagnostic time course, treatment, and in-hospital outcomes for patients with ST-segment elevation myocardial infarction presenting with nondiagnostic initial electrocardiogram: a report from the American Heart Association Mission: Lifeline program. Am Heart J. 2013;165:(1)50-6. PMID: 23237133
This is a registry study of 41.560 patients diagnosed with a STEMI. Of those patients, 4,566 had an initial ECG that was non-diagnostic. About ⅓ had converted to STEMI within 30 minutes of their first ECG, and 75% within 90 minutes. The groups were otherwise similar.
Bottom line: About 1/10 STEMIs are not evident on the initial ECG. If the story is good, get repeats.
When should we crack the chest?
Seamon MJ, Haut ER, Van Arendonk K. An evidence-based approach to patient selection for emergency department thoracotomy: A practice management guideline from the Eastern Association for the Surgery of Trauma. The journal of trauma and acute care surgery. 79(1):159-73. 2015. PMID: 26091330
This is a systematic review by the EAST group that included 72 studies an 10,238 patients looking to answer the question: should patients who present pulseless after critical injuries undergo emergency department thoracotomy to improve survival and neurologically intact survival?. Their review and recommendations are divided into 6 groups:
- Pulseless, signs of life, penetrating thoracic injury
- Strongly recommend ED thoracotomy (EDT)
- 182/853 patients survived hospitalization, 53/454 neurologically intact
- Pulseless, no signs of life, penetrating thoracic injury
- Strongly favour EDT
- 77/920 survived, 25/641 neurologically intact
- Pulseless, signs of life, penetrating extrathoracic injury
- Conditionally recommend EDT
- 25/160 survived, 14/85 neurologically intact
- Pulseless, no signs of life, penetrating extrathoracic injury
- Conditionally recommend EDT
- 4/139 survived, 3/6 neurologically intact
- Pulseless, signs of life, blunt injury
- Conditionally recommend EDT
- 21/454 survived, 7/298 neurologically intact
- Pulseless, no signs of life, blunt injury
- Conditionally DO NOT recommend EDT
- 7/995 survived, 1/825 neurologically intact
There a definitely a few issues with the data. Systematic reviews are only as good as the studies included, and none of the included studies were great. In case you were wondering, the reason that the denominator for neurologically intact survival and overall survival are different is that some studies didn’t report neurologic status.
Bottom line: This is a procedure we need to be prepared to do in the context of penetrating trauma patients who had signs of life. Even smaller community hospitals should have a plan for these patients before they arrive.
Ultrasound before thoracotomy?
Inaba K, Chouliaras K, Zakaluzny S. FAST Ultrasound Examination as a Predictor of Outcomes After Resuscitative Thoracotomy: A Prospective Evaluation. Annals of surgery. 262(3):512-8. 2015. PMID: 26258320
The criteria for thoracotomy based on ‘signs of life’ always seemed a bit soft to me. Could the omnipresent ultrasound probe help us make the decision to crack the chest? These authors prospectively enrolled all patients at their centre undergoing a resuscitative thoracotomy over the course of 3.5 years. They obtained cardiac views with an ultrasound on all these patients. In total, they performed 187 thoracotomies. 126 patients had cardiac standstill on ultrasound, and ZERO survived. If there was cardiac motion on ultrasound, 9/54 patients survived. The biggest problem with this data is probably the generalizability. 187 thoracotomies in 3 years is A LOT. My guess is these physicians are more skilled at both the thoracotomy (obviously) but also the cardiac ultrasound than I am. Might the ultrasound probe just delay the necessary procedure?
Bottom line: No cardiac activity on ultrasound might be a good reason not to perform a thoracotomy.
Some more trauma: NEXUS CT chest tool
Rodriguez RM, Langdorf MI, Nishijima D. Derivation and Validation of Two Decision Instruments for Selective Chest CT in Blunt Trauma: A Multicenter Prospective Observational Study (NEXUS Chest CT). PLoS medicine. 12(10):e1001883. 2015. PMID: 26440607 [free full text]
This is the second attempt at a NEXUS CT chest tool. This paper covers both the derivation and validation studies of the new tool. It total, they prospectively enrolled 11,477 blunt trauma patients over 14 years of age at 8 level 1 trauma centres. They came up with two different instruments: one just for major injuries and another for major and minor injuries. In the validation, the CT-All tool (designed to catch major and minor injuries) had a 99.2% sensitivity and 20.8% specificity for major injury, and a 95.4% sensitivity and 25.5% specificity for all injuries. One major problem is the validation only occurred in patients who actually had CTs (less than half of the cohort) so it is hard to say how it will work when applied to all comers. The authors think this will decrease CT scanning, but like all decision instruments, the implementation should be specifically studied. If applied to lower risk populations, it could actually increase scanning.
Bottom line: If you have ordered a CT chest for blunt trauma, you could check this rule to see if you could safely cancel the scan
Let’s do a couple papers on SVT. First: The Valsalva to rule them all
This one has been talked about a lot since it came out. It is a multi-centre, non-blinded randomized control trial of 428 adult patients with supraventricular tachycardia comparing the standard Valsalva maneuver to a modified Valsalva. The modified Valsalva was performed by forced blowing for 15 seconds in the sitting position (standard Valsalva), but then patients were immediately laid flat and had their legs elevated to 45 degrees for 15 seconds. (A video of the procedure can be seen here.) At one minute after the procedure 17% of the standard Valsalva group and 43% of the modified group were in sinus rhythm (OR 3.7 95%CI 2.3-5.8 NNT=3.8). This translated into 19% fewer patients requiring adenosine (69% vs 50%, p=0.0002, NNT=5.3). The authors say that blowing into a 10ml syringe will replicate the Valsalva they performed with fancier equipment.
Bottom line: This is a simple, free technique that might save our patient uncomfortable medical interventions. Using it until further research is done seems like a no brainer.
SVT #2: Why I never use adenosine
Lim SH, Anantharaman V, Teo WS, Chan YH. Slow infusion of calcium channel blockers compared with intravenous adenosine in the emergency treatment of supraventricular tachycardia. Resuscitation. 80(5):523-8. 2009. PMID: 19261367
This is a RCT of 206 adult patients with SVT randomized to either adenosine or a calcium channel blocker. The dosing of the CCBs was either verapamil 1mg/min to a max of 20 mg or diltiazem 2.5mg/min to a max of 50mg. Adenosine dosing was 6mg followed by 12 mg if needed. Calcium channel blockers did a better job converting to sinus rhythm (98% vs 86.5% p=0.002). 1 patient in the CCB group developed transient hypotension as compared to none in the adenosine group.
Bottom line: Calcium channel blockers are more effective than adenosine and don’t have the horrible side effects. I always start with a CCB, and my patients have thanked me every single time for not exposing them to the horrors of adenosine.
SVT#3: More adenosine bashing
Holdgate A, Foo A. Adenosine versus intravenous calcium channel antagonists for the treatment of supraventricular tachycardia in adults. The Cochrane database of systematic reviews. 2006. PMID: 17054240
Just to complete the topic, this is the Cochrane review looking at calcium channel blockers versus adenosine in SVT. They found no significant difference in either reversion or relapse. Obviously, minor adverse events (the horrible chest pains, shortness of breath, and headaches) were higher in the adenosine group (10.8 versus 0.6% p<0.001). There was no statistical difference in hypotensive events, but all that occurred were in the calcium channel blocker groups (3/166 patients as compared to 0/171 patients.) There were no major adverse outcomes.
Bottom line: Again, similar efficacy but your patients will love you if you shelf the adenosine.
Apneic oxygenation: does it help in critical care?
The FELLOW trial: Semler MW, Janz DR, Lentz RJ. Randomized Trial of Apneic Oxygenation during Endotracheal Intubation of the Critically Ill. American journal of respiratory and critical care medicine. 2015. PMID: 26426458
This is a randomized, controlled, non-blinded trial comparing apneic oxygenation during intubation to no apneic oxygenation in 150 adult patients in a single ICU. Apneic oxygen was provided by the addition of oxygen through nasal prongs at 15L/min. The primary outcome, lowest achieved oxygen saturation, was not different between the groups (median of 92% with usual care and 90% with apneic oxygenation). There were no differences in any of the secondary outcomes (incidence of hypoxemia, severe hypoxemia, desaturation, or change in saturation from baseline.) Apneic oxygenation has been shown to work in stable surgical patients – why would it be different here? The big reason is that this was not a comparison of apneic oxygenation to apnea, like would occur in a standard RSI. 73% of patients received either BiPAP or BVM during the apneic period. Of course nasal prongs aren’t adding anything to patients receiving positive pressure ventilation. These patients are not at all like the patients I generally intubate.
Bottom line: I will continue to use apneic oxygenation for standard RSI, but if my patient requires BiPAP or bagging for oxygenation, I will forget the nasal prongs.
A 3 wish program to personalize the death experience
Cook D, Swinton M, Toledo F. Personalizing Death in the Intensive Care Unit: The 3 Wishes Project: A Mixed-Methods Study. Annals of internal medicine. 163(4):271-9. 2015. PMID: 26167721
I think one of medicine’s greatest current failures is the way we deal with death. That is a problem, seeing as death is the only certainty in medicine. This is a qualitative description of a program designed to personalize death in the ICU. To honor each patient, they asked dying patients, their families, and the clinicians to make 3 wishes that might provide dignity for the patient. The wishes were mostly simple, but profound, such as using a patient’s nickname, allowing a mother to lie in bed with her dying son, organizing volunteer work for family members, or celebrating a birthday. There were 5 categories of wishes: 1) humanizing the environment; 2) personal tributes; 3) family reconnections; 4) rituals and observances; and 5) “paying it forward”. The authors thought these added value through three domains: dignifying the dying patient, giving the family a voice, and fostering clinician compassion.
Bottom line: I don’t care much about the evidence here: This is a great idea, and if I end up in your ICU I hope this is the kind of care I receive.
Maybe a better summary of this paper is on of my favorite videos by ZDoggMD: https://www.youtube.com/watch?v=NAlnRHicgWs
An end to the low risk chest pain madness?
Mahler SA, Riley RF, Hiestand BC. The HEART Pathway randomized trial: identifying emergency department patients with acute chest pain for early discharge. Circulation. Cardiovascular quality and outcomes. 8(2):195-203. 2015. PMID: 25737484
This is a prospective, randomized control trial of 282 adult patients with symptoms of possible ACS without ST elevation, randomized to the use of the HEART pathway or usual care. The HEART pathway is a combination of the HEART score with 0 and 3 hour troponins. It was a relatively low risk group, with 6.4% of patients having an MI at 30 days. Using the HEART pathway reduced the use of cardiac testing from 69% to 57%, and none of the low risk group had any adverse events. The HEART pathway also increased early discharges and decreased length of stay. The two major problems with this study are its small size and the American setting. Although the score allow more patients to be discharged home in a setting where everyone is admitted, the results might be different if your chest pain admission rate is low to begin with, like it is where I work.
Bottom line: The HEART score may help decrease testing in low risk chest pain patients, but more evidence is required
PRP: All the superstar athletes are all using it, so it must work
Filardo G, Di Matteo B, Di Martino A. Platelet-Rich Plasma Intra-articular Knee Injections Show No Superiority Versus Viscosupplementation: A Randomized Controlled Trial. The American journal of sports medicine. 43(7):1575-82. 2015. PMID: 25952818
This is a randomized, double blind, controlled trial comparing platelet rich plasma (PRP) injections to injections of hyaluronic acid for knee osteoarthritis. Each group got three weekly injections of their study medication. Symptoms and function were identical between the groups at 2,6 and 12 months. Considering that hyaluronic acid has been shown to have essentially no clinically relevant benefit, this comparison may as well have been with placebo. As a side note, it drives me nuts that so many people refer to this as “platelet rich plasma therapy”. “Therapy” implies to patients that it might actually do some good and skews the process of informed choice. So far, there is nothing therapeutic about platelet rich plasma.
Bottom line: Platelet rich plasma therapy sounded good in theory, but it looks like it will be another fruitless intervention.
The “gold standard” for PE isn’t so gold.
Hutchinson BD et al. Overdiagnosis of Pulmonary Embolism by Pulmonary CT Angiography. Am J Roentgenol. 2015; 205(2): 271-7. PMID: 6204274
The patient was low risk, but you decided to order the CT anyway. Thank goodness you did, because it is positive for a PE. Well, not so fast. This is a retrospective look at 937 CTPAs for PE over 1 year at a single center. They had 3 blinded radiologists review each study, using their consensus as the gold standard. Of the 174 studies that were initially read as positive, these radiologists disagreed with that read (thought it was a false positive) in 45 cases (25.9%). This is consistent with multiple other studies.
Bottom line: We are likely harming many patients with unnecessary lifelong anticoagulation. In borderline cases, it might be worth asking for a second opinion on the read of the CT.
How normal is normal saline?
SPLIT trial: Young P, Bailey M, Beasley R. Effect of a Buffered Crystalloid Solution vs Saline on Acute Kidney Injury Among Patients in the Intensive Care Unit: The SPLIT Randomized Clinical Trial. JAMA. 2015. PMID: 26444692
We have been hearing for a while now that normal saline, because of the large excess of chloride and resultant acidosis, is bad for sick patients. This is a multi-centre blinded, randomized trial of 2278 adult ICU patients comparing normal saline to a balanced solution (plasmalyte 148). There was no difference in the primary outcome of acute kidney injury (9.6% with plasmalyte and 9.2% with saline, p=0.77). There was also no difference in renal replacement therapy, ICU days, mechanical ventilation, or mortality. A few weaknesses of this study were that the median amount of fluid given was only 2L per patient and most patients received fluid prior to enrollment, a lot of which was balanced solution. The biggest problem for emergency medicine is that 70% of patients went to the ICU after elective surgeries, so these results are probably not generalizable to our septic patients who start out significantly acidotic.
Bottom line: Despite a lot of theory, there is still no good evidence that we should be giving up on normal saline.
Are delayed antibiotics truly a death sentence?
Sterling SA, Miller WR, Pryor J, Puskarich MA, Jones AE. The Impact of Timing of Antibiotics on Outcomes in Severe Sepsis and Septic Shock: A Systematic Review and Meta-Analysis. Critical care medicine. 43(9):1907-15. 2015. PMID: 26121073
People have been quoting a 7% increased mortality with every hour antibiotics are delayed for a long time. Unfortunately, this is based off a single study, and we seemed to forget somewhere along the line that association does not equal causation. This is a meta-analysis of 11 studies covering 16,178 patients with severe sepsis or septic shock. There was no difference in mortality comparing early and late antibiotics groups. Of course, all of these studies are observational, as no severe sepsis patients are being randomized to delayed antibiotics.
Bottom line: Obviously, give antibiotics if you know a patient has an infection – but there is reason to fight with administrators and government agencies if they try to make time to antibiotics a quality metric.
Turning down the heat: can acetaminophen save lives?
For some reason, people just love to hate on fever. It is present when people are sick, so it must be bad, right? We better rush to treat it. This is a randomized, double blind trial of 690 adult ICU patients with a fever and suspected infection, comparing acetaminophen 1 gram IV every 6 hours to placebo. Not surprisingly (unless you actually believed treating fever was helping patients) there was no difference in the primary outcome of ICU free days. There was also no difference in mortality at 28 or 90 days.
Bottom line: Tylenol is great, but it isn’t needed for febrile patients
Dopamine is having a tough run
Ventura AM, Shieh HH, Bousso A. Double-Blind Prospective Randomized Controlled Trial of Dopamine Versus Epinephrine as First-Line Vasoactive Drugs in Pediatric Septic Shock. Critical care medicine. 43(11):2292-302. 2015. PMID: 26323041
Sure, it’s a small trial – but it was looking at small patients, so that’s OK. This is a double-blind, randomized controlled trial of 120 pediatric patients with severe sepsis comparing epinephrine to dopamine as the first line vasopressor. The study was stopped early due to increased mortality in the dopamine group (20.6% versus 7%). They also note decreased mortality when epinephrine was given early through a peripheral IV or an IO. Mortality was not the primary outcome, and the trial was small, so I wouldn’t be shocked to see contradictory results in the future.
Bottom line: It’s rare to get this kind of RCT in pediatrics – this is definitely enough for me to shelf dopamine for epinephrine for the time being.
Ultrasound for CHF
Pivetta E, Goffi A, Lupia E. Lung Ultrasound-Implemented Diagnosis of Acute Decompensated Heart Failure in the ED: A SIMEU Multicenter Study. Chest. 148(1):202-10. 2015. PMID: 25654562
This is a multicentre, prospective cohort of 1005 ED patients looking to see if lung ultrasound could add to clinical judgement in the diagnosis of acute heart failure. The gold standard of heart failure was determined by a review of the final chart by a cardiologist and an emergency physician. This isn’t perfect, but there isn’t really a better option for CHF, and they were blinded to the ultrasound results and agreed with each other 97% of the time. Physician judgement alone for CHF is really good, with a sensitivity of 85.3% and a specificity of 90%. If you add ultrasound to this physician judgment, the sensitivity rose to 97% (95% CI, 95%-98.3%) and specificity to 97.4% (95% CI, 95.7%-98.6%), translating into positive and negative likelihood ratios of 22.3 and 0.03 respectively. The biggest caveat is that these were non-consecutive patients, because there had to be a doctor around with enough ultrasound skill (>40 scans) to get enrolled.
Bottom line: In trained physicians, lung ultrasound can help rule in and rule out acute CHF.
The new ACLS guidelines are out
The multiple AHA guidelines are in this issue of Circulation
The ERC guidelines are in Resuscitation
There is too much to go through in this format. The quickest summary is that there is nothing really game changing in these guidelines, so keep providing the high quality care you already do, and don’t rush to waste your money on a new ACLS course. If you want more information, I wrote a post about the biggest changes here: https://first10em.com/2015/10/21/acls-2015/
Cheesy Joke of the Month
Patient: Doctor, I broke my arm in 3 places. What should I do?
Doctor: Stop going to those places
#FOAMed of the month
I was incredibly impressed with the capacity for knowledge translation demonstrated by the free, open access medical education community this month when the new ACLS guidelines came out. Within a week, the internet was awash in summaries, podcasts, and infographics. If my quick summary wasn’t enough for you, here are a few other amazing resources: