Background: The electrocardiogram (ECG) is one of the most useful diagnostic studies for identification of acute coronary syndrome (ACS) and acute myocardial infarction (AMI). The classic teaching is ST-segment elevation myocardial infarction (STEMI) is defined as symptoms consistent with acute coronary syndrome (ACS) + new ST-segment elevation at the J point in at least 2 anatomically contiguous leads of at least 2mm (0.2mV) in men or at least 1.5mm in women in leads V2 – V3 and/or at least 1mm (0.1mV) in other contiguous leads or the limb leads, in the absence of a left bundle branch block, left ventricular hypertrophy, or other non-acute MI ST-segment elevation presentations. Unfortunately, the ECG may be non-diagnostic in nearly half of all patients who initially present with AMI. There are also STEMI equivalent patterns that are caused by occlusion of the coronary arteries that place a significant portion of the left ventricle at jeopardy and result in poor outcomes. This review article focused on 5 under recognized high-risk ECG patterns in the ACS patient that result in poor outcomes including malignant dysrhythmias, higher rates of cardiogenic shock, and death. Read more →
Background: Although non-contrast head CT (NCHCT) has near perfect sensitivity (98-100%) in detecting aneurysmal subarachnoid hemorrhage (SAH) when performed within 6 hours of headache onset, sensitivity declines after 6 hours. As a result of declining sensitivity, lumbar puncture (LP) continues to be part of the workup in suspected SAH. An LP gives providers the ability to perform CSF analysis for red blood cells and detect xanthochromia by visual inspection or spectrophotometry. In most of the world, including the United States, the predominant approach to identifying xanthochromia is visual detection. However, this technique is subjective and considered unreliable by many. Spectrophotometry is a more objective test but, has lower specificity, carries a higher cost and is unavailable in the majority of hospitals.
In patients with SAH diagnosed by NCHCT or suspected based on LP results, angiography (CTA or MRA) is typically performed to investigate for an aneurysm that requires neurosurgical intervention. Angiography is considered to be the “gold standard” test for looking for aneurysmal SAH although it is not without it’s own limitations (a small minority of the population will have benign aneurysms and these increase with age). Read more →
One of the major reasons contributing to dismal survival rates in out-of-hospital cardiac arrest (OHCA) is the lack of bystander initiated cardiopulmonary resuscitation (CPR). Even though the majority of OHCA is witnessed, only 1 in 5 patients will receive bystander initiated CPR . Survey studies have shown that bystanders are not wanting to do mouth-to-mouth resuscitation on strangers. Outside of early defibrillation, only early bystander initiated CPR has consistently been shown to improve neurologically intact survival in OHCA. So what about Cardiocerebral Resuscitation, also known as “Hands-Only” CPR? Read more →
Background: CT scans are frequently done after minor head injury to evaluate for intracranial hemorrhage. While CT scans are an excellent tool for diagnosing or ruling out this disorder, they are not without harms including radiation exposure, cost and department delays. Much of the time, CTs are negative, or find injuries for which no intervention is ever done and do not clinically affect the patient. Clinical Decision Instruments may aid clinicians in determining which patients are higher risk and require imaging and which do not. Read more →
The Ontario Prehospital Advanced Life Support (OPALS) Study
Background: Sudden cardiac arrest is common and, obviously, very bad. In the US, there are about 500,000 cardiac arrests each year. About half of these cardiac arrests are OHCA and the survival rate is pretty poor. The most recent survival estimates put it at 7 – 9.5% in most communities. About 10-12 years ago, the American Heart Association built the 4-step “chain-of-survival.”
- Step One – Early access to emergency care
- Step Two – Early CPR
- Step Three – Early defibrillation
There is little debate about these three steps as the sum of the data supports that they lead to better outcomes.
The 4th step in the chain, however, is slightly more controversial; early advanced care. This basically means rapid access to ACLS type resuscitation skills (intubation and intravenous drug therapy). Despite it being the 4th step, ACLS has little evidence to defend it. Read more →
Background: Left Bundle Branch Block (LBBB) on the ECG makes accurate recognition of ST-Elevation Myocardial Infarction (STEMI) rather difficult. The 1996 and 2004 American College of Cardiology/American Heart Association (ACC/AHA) STEMI guidelines recommended immediate reperfusion therapy for patients with potentially ischemic symptoms and new, or presumed new, LBBB. In 2013, this recommendation was removed from the guidelines. Historically, reperfusion decisions in LBBB have been determined by the original Sgarbossa criteria published in 1996, but there are three key limitations to the original study by Sgarbossa et al:
- The original Sgarbossa criteria (i.e. the “weighted” Sgarbossa criteria) depends on a point system that rely on 3 findings, only 2 of which would provide enough points (i.e. 3) to make the diagnosis of AMI. Using the Sgarbossa criteria without the point system (i.e. the “unweighted” Sgarbossa criteria) increases sensitivity but decreases specificity.
- Sgarbossa et al diagnosed AMI by creatine kinase MB (CK-MB) elevations instead of angiographic evidence of acute coronary occlusion (ACO), which limits the sensitivity of the rule because it combines NSTEMI and STEMI patients in the outcome definition
- Finally, Sgarbossa et al used an absolute criterion (5mm) rather than a proportional criterion for excessively discordant ST elevation lowering the sensitivity of the criteria.
The modified Sgarbossa criteria replaces the absolute 5mm discordant ST elevation with a proportion (ST elevation/S-wave amplitude ≤ -0.25). In other words, the modified Sgarbossa criteria only changes the last of the original Sgarbossa criteria with the first two criteria staying intact. Now, if any of these criteria are met, the cardiac catheterization lab should be activated. We have written on REBEL EM before about the modified Sgarbossa criteria and one of our conclusions was this rule looked very promising, but needed an external validation study. Well that study is now here and for full disclosure I am one of the authors on the paper. Read more →
Background: The traditional standard workup for ruling out subarachnoid hemorrhage (SAH) has been a non-contrast head CT and, if negative, a lumbar puncture. The thought behind this is that the sensitivity of head CT to rule out SAH is not 100% and declines over time and missing a SAH is potentially devastating. There has been a series of studies published in the past few years looking at the value of a negative head CT scan performed within 6 hours of headache onset in ruling out SAH. I have heard many say that if they have a negative Head CT at 6 hours or less in a neurologically intact patient they would not perform a lumbar puncture. Read more →
Background: Sudden cardiac arrest has very poor outcomes; less than 11% of patients in cardiac arrest in the Emergency Department survive to discharge from the hospital. The management of cardiac arrest is algorithmic because providers have limited tools at their disposal and limited knowledge of the patient’s past medical history. EKG is limited in its evaluation of cardiac function. Pulses are often difficult to palpate. The blood pressure cuff is often unreliable. As a result, there is a sense of futility when running resuscitations.
Transthoracic echocardiography (TTE) in the Emergency Department gave providers another tool to help guide management through direct visualization of cardiac activity, tamponade physiology, right heart strain, etc . It also offers prognostic value if there is no cardiac activity upon arrival to the Emergency Department on TTE, there is a near 0% chance of survival. However, TTE has its limitations: obesity, emphysema, poor windows, interrupts compressions, gel gets everywhere.
Transesophageal echocardiography (TEE) provides significant benefits when compared to TTE in the management of cardiac arrest in the emergency department. Read more →
I know, I know. We here at REBEL EM are normally very clinically oriented. We take recent articles or hot topics and give you the breakdown and clinical take home points. But a recent event happened that made me look at my own practice, and now on the other side, I feel that I am a better doctor. The hospital I was working at as medical director of the Emergency Department (ED) closed its doors. This was a hospital that had been in the community for more than 60 years. I won’t go into the reasons for closure, but rather, I would like to tell the story from the side of the ED provider and what I had to change until the lights were turned out. Read more →
Background: Fingertip amputations are not an uncommon injury seen in the emergency department. Treatment options range from healing by secondary intention to flap coverage or replantation. Selection of the appropriate treatment modality depends on the nature of the injury, the physical demands of the patient, and the patient’s co-morbidities. Prophylactic antibiotic use in patients with fingertip amputations is controversial. The routine use of prophylactic antibiotics is universally recommended on grossly contaminated wounds, in immunocompromised patients, and in injuries with extensively destroyed/devitalized tissue as it is thought the infection risk is high in these circumstances. However, many reflexively prescribe antibiotics prophylactically in all distal tip amputations. Moreover, there is often an underlying tuft fracture and we reflexively give these patients antibiotics because we were all taught that any open fractures require antibiotics in addition to usual fracture care. Prior studies on distal fingertip amputations and the use of prophylactic antibiotics suggest no change in infection risk with the routine use of antibiotics but these studies were small and have done little to inspire an antibiotic-restrictive approach universally. Read more →