Atrial Fibrillation, You’re a Heart Breaker, Dream Maker, Love Taker:

But At Least There is Low Risk for Thromboembolic Events With Speedy Conversion to Sinus Rhythm…

This post reviews the article from Weigner, Marilyn et al. “Risk for Clinical Thromboembolism Associated with Conversion to Sinus Rhythm in Patients with Atrial Fibrillation Lasting Less Than 48 Hours,” from the Annals of Internal Medicine in 1997 as part of the ongoing 52 article series.

Main Points:

  1. This article reveals only a 0.8% risk of clinical thromboembolic event for patients who were clinically estimated to be in atrial fibrillation for less than 48 hours.
  1. This trial data supports the recommendation for early cardioversion, either pharmacologic or through electric cardioversion, in patients with recent onset of symptoms without the need for prior diagnostic imaging to evaluate for clot burden.

Background:

Atrial fibrillation is a common arrhythmia and responsible for over 250,000 hospital admissions annually. Patients often feel the effects of depressed cardiac output from the loss of atrial systole and seek medical attention in hopes of improved quality of life. Patients may describe a range of symptoms including palpitations, dyspnea, dizziness, angina and fatigue. Studies have demonstrated that patients with atrial fibrillation for more than two days may have a greater than five percent risk of clinical thromboembolism and often require weeks of anticoagulation or screening with transesophageal echocardiography prior to cardioversion. This study sought to answer the question of whether or not patients who experienced only a short duration of symptoms were low risk for thromboembolic disease.

Details:

This was a prospective study of consecutive patients at two academic medical centers, Beth Israel Deaconess Medical Center in Boston, MA and the John Dempsey Hospital and University of Connecticut Health Center in Farmington, CT. 1822 adult patients with a diagnosis of atrial fibrillation were screened and 375 patients who were clinically estimated to have symptoms for less than 48 hours were enrolled. Those patients whose duration of symptoms were unclear or had already initiated long term anticoagulation with warfarin were excluded. Patients with a previous history of thromboembolic events were not excluded, but one patient who had an acute thromboembolism was not enrolled in the trial. Clinical and transthoracic echocardiography data and outcomes were collected from review of the medical records. Clinical embolic events were considered if they occurred during the index hospitalization or within one month after conversion to sinus rhythm. Conditions that may have predisposed patients to atrial fibrillation included: previous history of atrial fibrillation (181 patients, 48.3%), hypertension (156, 41.7%), coronary artery disease (114, 30.4%), infection (25, 6.7%), history of thromboembolism (23, 6.1%), excessive alcohol use (22, 5.9%), rheumatic heart disease (7, 1.9%). Patients were noted to have left atrial dimensions of 4.2 +/- 0.7cm (normal ≤ 4.0cm) and a left atrial length of 5.7 +/- 0.7cm (normal ≤ 5.2cm) based on transthoracic echocardiogram data. 218 out of 280 patients who had echocardiograms performed were noted to have at least some evidence of mitral valve regurgitation with 61 patients noted to have either moderate or severe regurgitation.

Patients converted back to a normal sinus rhythm either spontaneously or through pharmacologic or electric cardioversion methods. Conversion was considered spontaneous if it occurred without the use of medications or electricity or in the setting of use of ventricular rate-controlling agents (digoxin, beta-blockers, and calcium channel blockers).

Three patients (0.8%, 95% CI 0.2-2.4) were noted to have a clinically significant thromboembolism and surprisingly all converted spontaneously. The cases included a left parietal embolic stroked in an 86 year old female with history of hypertension; a right proximal brachial artery embolus in an 83 year old female with coronary artery disease; and a transient ischemic attack in an 89 year old female with a recent diagnosis of pneumonia.

This study was a consecutive series that relied on both real time data gathering as well as retrospective chart review.

Level of Evidence:

This study was graded a level II based on the ACEP Clinical Policy Grading Scheme for prognostic questions and had only minimal methodological flaws.

Surprises:

The three patients in this trial were identified as having increased risk for thromboembolism based of the Stroke Prevention and Atrial Fibrillation Study I and II, however, how best to achieve post conversion anticoagulation in the era of direct oral anticoagulants remains a hot topic for further study and debate.

Relevant articles:

Mookadam, M. Shamoun FE. Mookadam, F. “Novel Anticoagulants in Atrial Fibrillation: A Primer for the Primary Physician.” J Am Board Fam Med, 2015, 28(4):510-22

Source Articles:

Weigner, M. Caulfield, T. Danias, P. et al. “Risk for Clinical Thromboembolism Associated with Conversion to Sinus Rhythm in Patients with Atrial Fibrillation Lasting Less Than 48 Hours.” Annals of Internal Medicine, 1997, (126):615-20.

Faculty Reviewer: Dr. Siket

Spare the Tube, Save a Life

This is part of a recurring series examining landmark articles in Emergency Medicine, in the style of ALiEM’s 52 Articles.

Discussing:

Brochard, L. Mancebo, J. Wtsocki, M. et al. “Noninvasive Ventilation for Acute Exacerbations of Chronic Obstructive Pulmonary Disease.” NEJM 1995, 333(13):817-22.

Main Points:

  1. In this randomized prospective multicenter trial of 85 patients admitted to ICUs throughout Europe with COPD exacerbations, noninvasive ventilation reduced the need for endotracheal intubation, length of stay and in-hospital mortality rate.
  1. 31 of the 42 patients in the standard arm required intubation, compared to 11 of 43 patients in the noninvasive arm (p<0.001). These results were consistent among the five centers studied. The mortality rate and length of stay was similar in the two groups in whom endotracheal intubation was required, suggesting that the benefits observed in noninvasive ventilation resulted from lower rates of intubation.
Figure 1. Mask used to deliver noninvasive ventilation

Figure 1. Mask used to deliver noninvasive ventilation

Background:

COPD exacerbations often manifest as acute hypercapnic ventilatory failure and endotracheal intubation can be a life-saving procedure. This intervention, however, is not without associated risks both during the time of the procedure as well as later in the course of the patient’s care. This patient population is at risk for hemodynamic compromise during intubation and may be difficult to manage on the ventilator due to a multitude of concerns including air trapping and tachypnea. The risk for ventilator associated pneumonia and other complications secondary to being intubated for prolonged periods of time are also worth considering.

Brochard and his colleagues investigated the use of noninvasive ventilation in COPD exacerbations in hopes of reducing mortality through the reduction of intubation. Thiswas a multicenter prospective randomized study that recruited patients in five European ICUs. The primary and secondary outcomes were patient-centered and this article from 1995 has clearly framed the manner in which we manage the sick COPD patient today. The medications used and manner in which noninvasive ventilation is employed has evolved since the publication and a comprehensive review of management was published in 2010 by the American Academy of Family Physicians. ACEP also has published clinical guidelines on use of noninvasive ventilation in 2010.

Details:

This prospective multicenter study enrolled 85 out of 275 patients admitted to the ICU with COPD or a high probability of the disease based on careful history, physical examination and chest x-ray. Patients were selected if they had a respiratory acidosis and elevated bicarbonate level. Additional criteria included dyspnea for less than two weeks and at least two of the following: respiratory rate >30 BPM, partial pressure of arterial O2 <45 mm Hg, arterial pH <7.35 after the patient was breathing room air for at least 10 minutes. The exclusion criteria included: respiratory rate <12 BPM, need for immediate intubation-defined by strict criteria in the paper, already intubated, use of sedative drugs in the past 12 hours, CNS disorder, cardiac arrest in the past five days, cardiogenic pulmonary edema, neuromuscular or skeletal disorder, upper airway obstruction or asthma, clear cause of decompensation requiring treatment, or facial deformity. Patients were either assigned to the standard arm which included treatment with: maximum of 5LPM O2 by nasal prongs with goal O2 saturation >90%, medications such as subcutaneous heparin, antibiotic agents and bronchodilators (subcutaneous terbutaline, aerosolized or intravenous albuterol, corticosteroids or intravenous aminophylline), correction of electrolytes. The noninvasive arm received the same medications with the addition of periods of noninvasive ventilation. The same apparatus was used at all five sites to deliver pressure support of 20 cm H20 with an expiratory pressure that was atmospheric. Patients underwent noninvasive ventilation for at least six hours a day with overall duration determined by clinical criteria and arterial blood gal levels.

In order to standardize care, the authors created major and minor criteria as objective markers for the need to perform endotracheal intubation. The major criteria included: respiratory arrest, respiratory failure with LOC or gasping for air, psychomotor agitation making nursing care impossible and requiring sedation, HR<50 BPM with loss of alertness, hemodynamic instability with SBP <70 mm Hg. There was a series of minor criteria also relating to vital sign instability, mental status changes or arterial pH <7.3. In both groups the presence of one major criterion was an indication for intubation. After the first hour of treatment the presence of two minor criteria was an indication for intubation.

Patients were evaluated at the one hour, three hour and 12 hour mark following the initiation of therapy. The primary outcome examined was the need for endotracheal intubation with secondary end points including length of stay, complications not present on admission (pneumonia, barotrauma, gastrointestinal hemorrhage, renal insufficiency, neurologic events and pulmonary embolism), duration of ventilatory assistance, and mortality rate during hospitalization. 31 of the 42 patients in the standard arm required intubation, compared to 11 of 43 patients in the noninvasive arm (p<0.001). Per the authors, these results were consistent among the five centers studied, however, examining table 2 sites one and two seemed to have high percentages of intubation, 100 and 83 percent respectively, compared to the others. This may be skewed by the overall low numbers studied. Patients who ultimately were intubated both in the standard and noninvasive arms had extended ventilation time with 17 +/- 21 days and 25 +/- 17 days respectively. Complications and events leading to death are shown in Table 4.

Level of Evidence:

This study was graded a level I based on the ACEP Clinical Policy Grading Scheme for therapeutic questions.

Surprises:

The use of pressure support of 20/0 is quite different from the manner in which many providers initiate noninvasive ventilation today. This may be secondary to the limitations of the technology at the time because the photograph in figure 1 (see above) displays a mask that appears different from what you find on modern machines.

Relevant articles:

Ahn, J. Pillow, T. “Focus On: Noninvasive Positive Pressure Ventilation in the Emergency Department.” 2010, http://www.acep.org/Clinical—Practice-Management/Focus-On–Noninvasive-Positive-Pressure-Ventilation-In-the-Emergency-Department/

Evensen, A. “Management of COPD Exacerbation.” Am Fam Physician 2010, 81(5): 607-13. http://www.aafp.org/afp/2010/0301/p607.html

Faculty Reviewer: Dr. Siket

Source Articles:

Brochard, L. Mancebo, J. Wtsocki, M. et al. “Noninvasive Ventilation for Acute Exacerbations of Chronic Obstructive Pulmonary Disease.” NEJM 1995, 333(13):817-22.

Hold the Fluids: Rethinking Early Crystalloid Resuscitation in Penetrating Trauma

By: Dr. Maddie Boyle

This is part of a recurring series examining landmark articles in Emergency Medicine, in the style of ALiEM’s 52 Articles.

This blog post reviews the article by: Bickell WH, et al. Immediate Versus Delayed Fluid Resuscitation for Hypotensive Patients with Penetrating Torso Injuries. NEJM. 1994; 331 (17): 1105 – 1109.

Main Points:

  1. Early, large volume crystalloid resuscitation in the trauma patient with penetrating wounds and hypotension may lead to hydraulic disruption of a formed clot and a dilutional coagulopathy, thereby exacerbating hemorrhage and decreasing survival.
  1. Restricting isotonic fluids in the penetrating trauma patient with hypotension prior to operative intervention (where definitive hemorrhage control can be achieved) lead to higher survival rates when compared to those individuals treated with early, aggressive isotonic fluid resuscitation (70% vs 62%, p=0.04). This paper suggests a potential adverse effect from aggressive crystalloid administration and emphasizes the importance of prioritizing surgical management in the patient with hemorrhagic shock from penetrating trauma.

Background:

Historically, the standard approach for the trauma patient with hypotension has been aggressive volume resuscitation with crystalloid fluids in order to restore circulating volume and maintain organ perfusion. More recent studies suggest that aggressive crystalloid fluid administration prior to definitive hemorrhage control may be detrimental. Aggressive fluids in the bleeding patient may be deleterious for multiple reasons, most notably the risk of dislodging a softly form clot at the injury site with restoration of blood pressure and the risk of increased bleeding secondary to dilution of clotting factors when large volumes of crystalloid fluids are infused. Recent literature such as the PROPPR trial has investigated colloid based transfusion strategies, however, this study predates the data gathered from the recent Iraq and Afghanistan Wars.

The goal of this study was to evaluate fluid administration in hypotensive patients with penetrating torso trauma and determine whether delayed fluid-resuscitation (after operative intervention), compared to an early fluid administration conferred a survival benefit. Researchers performed a prospective, single center trial comparing immediate fluid resuscitation vs. delayed fluid resuscitation in patients with penetrating torso trauma with a pre-hospital systolic BP <90 mmHg requiring operative intervention for hemorrhage control. The study found a mortality benefit favoring delayed resuscitation: 70% of patients enrolled in the delayed-resuscitation group survived vs. 62% of patients in the immediate-resuscitation group (p=0.04). This study highlights numerous important questions regarding fluid strategy in the trauma patients, including the type of resuscitative fluid, the volume and timing of fluid administration. The results of this investigation continued to be queried today as research examines permissive hypotension and damage control resuscitation strategies in the trauma patient.

Strengths:

1: Adequate power.
2: Intention-to-treat analysis.

Criticisms:

1: Semi-randomized, non-blinded.
2: Generalizability: Study population was largely young, healthy adult males.
3: Feasibility: The average time elapsed from ambulance call to operative intervention was approximately 2-hours for each study group. This type of rapid response and expedited time to operative intervention may not be attainable by many hospitals.
4: External validity: study cannot be applied to patients with blunt trauma, traumatic brain injury (where fluid resuscitation to achieve blood pressure control is paramount) or in those penetrating trauma patients with delayed presentation.
5: No mention of neurologic outcome with regards to survival benefit.

Details:

Prospective, single-center trial.

Population: Adults or adolescents (age ≥16 years) with gunshot or stab wounds to the torso who had a SBP ≤ 90 mm Hg in the field, including those patients with no blood pressure at the time of initial paramedic evaluation.

Patients were separated into two treatment groups based on the day of the month. Patients injured on even-numbered days were assigned to the immediate-resuscitation group, whereas those injured on odd-numbered days were treated in the delayed-resuscitation group. Patients in the immediate-resuscitation group received isotonic crystalloid (ringer’s acetate) en route, and those with SBP <100 mm Hg upon arrival in the ED received continuous infusion of crystalloid or pRBCs when necessary as determined by standards established by the American College of Surgeons Committee on Trauma. The delayed-resuscitation group did not receive fluids, regardless of clinical condition, outside of those small infusions required to keep lines patent. Otherwise, the two treatment groups were treated identically in terms of pre-hospital and trauma care. The average time from emergency dispatch to surgical intervention was approximately 130 minutes in both groups.

Surgical interventions were dictated by the injury and included thoracotomy within the ED, thoracotomy in the OR, laparotomy, neck exploration, and groin exploration. During surgical intervention, IV crystalloid and pRBCs were given as needed, independent of study group assignment in order to maintain SBP of 100 mm Hg, hematocrit ≥ 25% and urinary output ≥ 50 cc/hr in both treatment groups. The total volume of crystalloid and colloid fluids provided in the OR was not statistically different between the two study arms, however, the rate of intraoperative fluid administration was noted to be 117 +/- 126 for the immediate resuscitation group and 91+/- 88 for the delayed resuscitation group with a p value of 0.008.

The primary outcome measure was survival, defined as patients who did not die during hospitalization. Secondary outcome measures included six prospectively identified post-operative complications including: sepsis, coagulopathy, acute renal failure, ARDS, pneumonia and wound infection.

598 patients were ultimately considered for the study. 309 were enrolled in the immediate-resuscitation group and 289 in the delayed-resuscitation group. The patients were similar in their baseline demographics and clinical condition. Of the 598 patients, 70 died before operative intervention. The remaining 528 had an operative intervention: 260 patients in the delayed-resuscitation group and 268 patients in the immediate-resuscitation group.

The mean fluid administration prior to operative intervention in the immediate-resuscitation group was 2611 ml. The mean fluid administration prior to operative intervention in the delayed-resuscitation group was 386 ml.

The overall rate of survival was higher in the delayed-resuscitation group vs. immediate-resuscitation (70% vs 62%, p-0.04). The immediate-resuscitation group trended towards more intraoperative fluid loss (p=0.11) and required a higher rate of intraoperative fluid delivery in order to maintain SBP >100 (117 cc/hr vs. 91 cc/hr, p=0.008). There was a trend towards more complications (ARDs, pneumonia, etc.) in the immediate-resuscitation group compared to the delayed-resuscitation group (p-0.08), however, no definitive explanation for why this may have occurred was discussed.

The authors of this study propose that their results suggest that aggressive fluid administration in the patient with penetrating trauma should be delayed until the time of operative intervention. They suggest a risk for greater bleeding, hemodilution and coagulopathy with aggressive fluid administration. The authors acknowledge the limitations of their study, most importantly its inapplicability to blunt trauma patients and patients with severe head injuries, but advise similar studies in these groups in the future.

Level of Evidence:

Class II utilizing the ACEP grading scheme for therapeutic questions

Relevant articles:

Timing and volume of fluid administration for patients with bleeding
Hypotensive resuscitation strategy reduces transfusion requirements and severe postoperative coagulopathy in trauma patients with hemorrhagic shock: preliminary results of a randomized controlled trial.
PROPPR trial

Source Article:

Bickell WH, et al. Immediate Versus Delayed Fluid Resuscitation for Hypotensive Patients with Penetrating Torso Injuries. NEJM 1994; 331 (17): 1105 – 1109.

 

Resident Reviewer: Dr. Anatoly Kazakin
Faculty Reviewer: Dr. Matt Siket

The Central Line Part 2: Technique & Procedural Steps

a blog series on emergency medicine procedures

In the last post (the central line part 1) we focused on the indications/contraindications and anatomic considerations. Here we focus on technique and procedural steps. Enjoy. 

 

HUNTING & GATHERING

*note: images shown in this section are institution-specific (Rhode Island Hospital Emergency Department) 

Find a computer with a functioning Topaz to obtain informed consent:

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Go to this corner in any critical care room (here is a closer look) and obtain a central line kit:

OR

Finally, obtain these items:

  • mayo stand
  • sterile gloves
  • chlorhexidine scrub
  • 2-3 sterile saline flushes
  • non-sterile marking pen
  • ultrasound machine and ultrasound probe cover
  • in kit: hat, gown, facemask

 

PREP

PRE-STERILITY:

  • Open kit and empty sterile contents onto the field
  • ULTRASOUND:
    • Plug in ultrasound machine. It WILL run out of battery if you don’t and the screen will shut off in the middle of the procedure
    • Test your US probe orientation: tap gently on left side of probe…this should match left side of your screen
    • Examine the target vein: is it compressible? Is it plump and easily visualized?
  • PATIENT:
    • Position the patient
    • Scrub target area with chlorhexidine
    • Mark the site

TIMEOUT! 

…and document it:

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STERILIZE.

Watch this video. 

From EMCrit.org, Scott Weingart, RACC Sterile Line Preparation

Continue reading

Time to Abandon Epinephrine for OHCA?

This is part of a recurring series examining landmark articles in Emergency Medicine, in the style of ALiEM’s 52 Articles.

Discussing: Wenzel, K. et al. A comparison of vasopressin and epinephrine for out-of-hospital cardiopulmonary resuscitation. N Engl J Med 2004;350(2):105-113.

Main Points:

  1. For out-of-hospital cardiac arrest (OHCA), vasopressin was similar to epinephrine in patients with ventricular fibrillation or pulseless electrical activity, with regards to survival to hospital admission and survival to hospital discharge. Vasopressin was noted to be superior, in both outcomes, for patients with asystole.
  1. In patients with refractory cardiac arrest and no ROSC, vasopressin followed by epinephrine may be more effective than epinephrine alone.

Background:

With more than 600,000 sudden death in North America and Europe annually, optimization of CPR is crucial to improve a patient’s chance of survival. Epinephrine use has become controversial as it induces increased myocardial consumption and ventricular arrhythmias post-resuscitation. Endogenous vasopressin levels have been known to be elevated in successfully resuscitated patients. In small prior studies, vasopressin has been associated with higher rate of short term survival and improved blood flow to vital organs when compared to epinephrine. Current guidelines recommend the use of epinephrine during cardiac resuscitation, with vasopressin as a secondary alternative.

Details:

This study was a double-blind, prospective randomized clinical trial, conducted in 44 Emergency Medical Service units in three European countries, including those with OHCA unresponsive to defibrillation. 1186/1219 patients with OHCA were included in the trial with randomization to two injections of either 40 IU of vasopressin or 1 mg epinephrine, followed by additional treatment with epinephrine at the discretion of the emergency physician managing the resuscitation. Average age 66 years, 70% men, 61% attributed to cardiac causes, 78% arrests witnessed. 33 patients were excluded due to a missing study drug code. The rates of hospital admission were similar between the two treatment groups for patients with ventricular fibrillation (46.2 vs 43%, p=0.48) and pulseless electrical activity (33.7 vs 30.5%, p=0.65). Patients with asystole treated with vasopressin were more likely to survive to hospital admission (29.0 vs 20.3%, p=0.02) and hospital discharge (4.7 vs 1.5%, p=0.04). Among 732 patients without ROSC, additional treatment with epinephrine resulted in improvement in rates of survival to hospital admission (25.7 vs 16.4%, p=0.002) and discharge (6.2 vs 1.7%, p=0.002) in the vasopressin group, but not the epinephrine group. Continue reading

A True Orthopedic and Vascular Emergency

Case: A 76-year-old male presents after falling down a long flight of stairs. On exam the patient has multiple obvious external injuries, including a grossly deformed right shoulder with a large overlying hematoma. His chest x-ray and shoulder x-ray demonstrate a superiorly and laterally displaced right scapula, as well as a comminuted right scapular fracture and clavicle fracture. On further CT imaging, the patient has subtle widening of the scapulothoracic articulation.

OneQuestion: What potentially devastating injury should be considered in this patient?

Continue reading

52 Articles: Lysis vs Transfer for PCI (NEJM 2003)

ST segments:
fear
a lytic in my hand,
or transfer?

-Unknown, 2015

This is part of a recurring series examining landmark articles in Emergency Medicine, in the style of ALiEM’s 52 Articles.

Discussing:

Andersen et al., NEJM 2003.  A Comparison of Coronary Angioplasty with Fibrinolytic Therapy in Acute Myocardial Infarction.

Main Points:

  1. This prospective randomly-controlled trial investigated whether patients with STEMIs who presented to community hospitals would benefit from transport to specialized centers for percutaneous coronary intervention (PCI) rather than remaining at the local hospital for fibrinolysis. The authors demonstrated an almost 5% reduction in reinfarction rate at 30 days between the two groups.
  1.  STEMI patients that presented to community centers and received aspirin+metoprolol+heparin+PCI within 2 hours, including transfer time, had statistically significantly fewer reinfarctions at 30 days than the STEMI patients who remained at the initial facility andon alteplase+aspirin+metoprolol+heparin.  Ultimately, PCI was shown to be superior to fibrinolytic if available in a timely fashion.

Background:

It is now an established tenet that timely PCI in an experienced center by experienced interventionalists is the best treatment for STEMI.  Historically, with no PCI available at the presenting facility, STEMI patients received anticoagulation and fibrinolytics.  But there were obvious and dangerous concerns in applying a “PCI-or-bust” policy universally, as there are only so many PCI centers to drive patients to, and “time is myocardium.”  So the best treatment for the patient with a STEMI in the middle of the proverbial forest was unknown.  Lyse or transfer?  This study made significant progress towards helping us answer this question.

Methods:

1572 patients were enrolled, 1129 from 24 referral hospitals and 443 from 5 PCI centers.  All of these patients were randomly assigned to receive lysis & anticoagulation (LA) or anticoagulation & PCI (APCI), with the patients from the referral hospitals therefore being transferred for their PCI.  And yes, patients who presented to PCI centers and were assigned LA therefore did not receive PCI.  Risk characteristics of all the patients were similar.  LA patients received 300mg aspirin PO, 20mg metoprolol IV, an “accelerated” alteplase treatment (15mg bolus + 0.75mg/kg over 30min + 0.5mg/kg over the next 60min), and unfractionated heparin for 48h (5000U bolus + infusion titrated to aPTT 70-90sec).  APCI patients received 300mg aspirin IV, 20mg metoprolol IV, unfractionated heparin (10,000U bolus + infusion during procedure to activated clotting time 350-450s).  In patients receiving PCI, GPIIb/IIIa blockers were given at discretion of proceduralist, arteries were treated only if stenosed >30% or if TIMI “flow grade” was <3, non-infarct-related arteries were NOT intervened on, and all patient received Ticlodipine (500mg) or Clopidogrel (75mg) for 1 month afterwards.  The primary endpoint was a composite of death from any cause, clinical reinfarction, or disabling stroke at 30 days follow up.

Results:

  • For patients presenting to PCI centers, there was a 45% reduction in composite outcome with PCI, from 12.3% in the LA group to 6.7% in the APCI group (P = 0.05).
  • For patients presenting to referral hospitals, there was a 40% reduction in the composite outcome with PCI, from 14.2% in the LA group to 8.5% in the APCI group (P = 0.002)
  • Driving the difference within the composite outcome was clinical reinfarction: 1.6% in all APCI vs 6.3% in all LA (P =  0.001).  Differences in death and stroke rates at 30 days were not statistically significantly different between all APCI and all LA patients, whether they were transferred to a PCI center or were already there.
  • The median distance from referral site to PCI center was 50 km
  • Transfer was highly protocolized, with emphasis on shaving-off every precious second of ischemic time.  This cooperation and efficiency resulted in 96% of referral patients landing on the nearest participating PCI table in 2 hours or less.
  • The study was stopped after the 1129 patients, when the third interim analysis showed referral APCIs were reinfarcting less than the referral LAs; this was built into the design as a study cutoff as it implies that APCI is better in both settings.

Discussion:

  • The bottom line is the balance between the proven benefits of PCI and the ischemic time on the myocardium.  There are many variables at play in the “lyse vs transfer (vs both)” decision (see below). These variables include: location and severity of the ischemia, comorbidities and stability of the patient, EMS capabilities, distance, receiving PCI center experience, available medications, etc.  The decision may not always be clear, every patient is probably different, and there is an overwhelming amount of research on this topic.  Do your best.
  • Implementing the airtight transfer logistics they executed here is an obstacle, science aside.
  • In hindsight, your heart has to go out (no pun intended) to the 12.3% of LA patients who presented to a PCI center, got heparin & alteplase, and had a poor outcome.  Their willingness to participate has certainly saved lives.
  • Did you notice that the referred APCI patients did not receive fibrinolysis, only asa, metoprolol, and UFH?  The older research on immediate PCI after fibrinolysis showed no benefit and increased adverse effects.  New and ongoing research on “facilitated PCI,” or PCI after fibrinolysis, using ever-advancing interventional equipment and techniques, may be changing this for some high risk patients for whom PCI is not available within 90 minutes.  For further reading, see these:

Herrmann HC, et al.  Benefit of facilitated percutaneous coronary intervention in high-risk ST-segment elevation myocardial infarction patients presenting to nonpercutaneous coronary intervention hospitals.  JACC Cardiovac Interv.  2009 Oct;2(10):917-24.

Ellis SG, et al.  Facilitated PCI in patients with ST-elevation myocardial infarction.  N Engl J Med. 2008 Maay 22;358(21):2205-17.

Ellis SG, et al. Facilitated percutaneous coronary intervention versus primary percutaneous coronary intervention: design and rationale of the Facilitated Intervention with Enhanced Reperfusion Speed to Stop Events (FINESSE) trial. Am Heart J. 2004; 147: E16.

Level of Evidence:

Based on the ACEP grading system for therapeutic questions this study was graded level I.

Surprises:

The study inclusion criteria was defined as the symptoms for greater than 30 minutes, but less than 12 hours with associated cumulative ST-segment elevation of at least 4mm in at least two contiguous leads.

Resident Reviewer: Dr. Kazakin
Faculty Reviewer: Dr. Siket

The Central Line Part 1: The Basics

a blog series on emergency medicine procedures

In this first installment on central lines, we discuss central line indications/contraindications/alternatives, anatomic considerations, and the upsides and downsides of the 3 major sites (subclavian, internal jugular, and femoral)

Indications specific to the ER

  • Administration of harsh or concentrated fluids
  • High volume, high flow fluid administration
  • Emergency venous access
    • Alternatives: EJ, IO, ultrasound-guided peripheral IV
  • Conduit for transvenous pacer or dialysis catheter

Contraindications

  1. Soft tissue infection overlying site
  2. Traumatic or congenital distortions
  3. Superior vena cava syndrome
  4. Deep venous thrombosis in vessel of choice
  5. Coagulopathies
  6. Combative or uncooperative patients

troubleshooting

TROUBLESHOOTING: How to solve the above contraindications…

  • 1-4: move to another site
  • 5: consider reversal agents
  • 6: consider sedation and/or intubation, depending on the case
LOCATION

SUBCLAVIAN

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From Netter’s Atlas of Human Anatomy, 4th ed, 2006 

Pathway

Subclavian vein and IJ –> brachiocephalic vein + contralateral brachiocephalic vein –> SVC

Where it is

Posterior to medial 1/3 of clavicle AND anterior to 1st rib

Anatomic awareness Continue reading

Overly Traumatic: A Teenager Elbowed in the Stomach

Link

Overly Traumatic: A Teenager Elbowed in the Stomach

Case: 

A 17 yo healthy M presents with abdominal pain and a syncopal episode several hours after getting elbowed in the stomach at a soccer game.

PMH: Intermittent asthma

ROS: Sore throat, cough and fatigue x 1 week.

Physical Exam:

VS: T 98.3 °F | HR 90 | BP 129/60 | RR 16 | SpO2 100%

Pale but comfortable and alert. Abdomen diffusely tender, guarding in the upper quadrants. Exam otherwise unremarkable.

FAST exam: 

RUQ: Free fluid in Morrison’s pouch & at the tip of the liver

LUQ: Free fluid in splenorenal recess & bowel floating in free fluid

Transverse Bladder: Large amount of fluid & clotted blood anterior to the bladder

Click ahead to reveal diagnosis

Continue reading

The Cricothyrotomy Part 3: Pediatric Points

a blog series on emergency medicine procedures

PEDIATRIC POINTS

In our last 2 posts (the cricothyrotomy part 1 and the cricothyrotomy part 2), we focused on adults. That is because the open surgical airway is often contraindicated in children as we discuss below, and there is an alternative method depending on age.

pearl12

PEARL: the cricothyroid membrane in children is significantly different…

Ped cric anat

From Roberts and Hedges’ Clinical Procedures in Emergency Medicine, 6th ed, 2013

  • Smaller
  • More anterior
  • Funnel shape
  • Structures like the larynx are more difficult to stabilize

pearl12

PEARL: in the majority of cases, open surgical cric on children is contraindicated

  • Children younger than 10-12 years old should not have an open surgical cricothyrotomy according to most emergency medicine textbooks
  • Why: risk of injuring important structures due to the anatomical differences listed above
  • Instead, if a non-invasive airway is impossible, perform a percutaneous needle cricothyrotomy

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PEARL: what type of ventilation to use

  • Bag ventilate if the patient is < 5 years old (risk of barotrauma with jet)
  • Jet ventilate if the patient is greater than 5 years old

 

SUMMARY

Child < 10-12 years old, cannot intubate, cannot ventilate, and rescue airway devices not working? Perform percutaneous needle cricothyrotomy (see below).

< 5 years old? Bag ventilate.

> 5 years old? Jet ventilate.

 

TECHNIQUE

  • Percutaneous needle puncture of the cricothyroid membrane
  • Translaryngeal ventilation (PTLV) by jet insufflation OR bag insufflation (age dependent)

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From Roberts and Hedges’ Clinical Procedures in Emergency Medicine, 6th ed, 2013

From Beck et al, Academic Emergency Medicine, Percutaneous Transtracheal Jet Ventilation, 2011 

 

Please also view these resources from our own Brown faculty!

Dr. Valente Sim Video 

Procedurettes Junior Jet Job

 

PLEASE SHARE ANY PEDIATRIC POINTS ON THE CRICOTHYROTOMY IN THE COMMENTS SECTION! 

 

Textbook References

Hebert R, Bose S, Mace. Cricothyrotomy and Percutaneous Translaryngeal Ventilation. Chapter 6, 120-133.e2. In: Roberts J, et al. Roberts & Hedges’ Clinical Procedures in Emergency Medicine. 6th Saunders; 2013.

Smith M. Surgical Airway Management. In: Tintinalli JE, et al. Tintinalli’s Emergency Medicine. 7th ed. New York: McGraw-Hill; 2011.

Walls RM: Airway. In Marx JA, Hockberger RS, Walls RM: Rosen’s Emergency Medicine: Concepts and Clinical Practice, 6th ed, vol. 1. Philadelphia, Elsevier, 2006, pp 2-25.

Image References

Hebert R, et al. Cricothyrotomy. In: Procedures Consult. Elsevier; 2008.

Authorship

Faculty Reviewers: Gita Pensa MD and David Lindquist MD 

Author: Jonathan Ameli MD