TXA Literature Review

Author: Alexandra Murray, DO PGY1
Mercy St. Vincent Medical Center Emergency Medicine

Originally Published: Modern Resident - December-January 2016

What is tranexamic acid (TXA)?
When the body experiences vascular injury, the hemostatic system tries to maintain circulation by balancing the formation and degradation of blood clots. In response to severe blood loss, this balance is challenged and hyper-fibrinolysis can occur. The conversion of plasminogen to plasmin plays a large role in fibrin binding and degradation. Tranexamic acid is a synthetic derivative of lysine that reversibly blocks binding sites on plasminogen and inhibits fibrinolysis.[1] TXA has been approved by the FDA since 1986 as an antifibrinolytic and has been marketed for menorrhagia (Lysteda) and dental hemorrhage in hemophiliacs (Cyklokapron).[2,3] More recently, TXA has been investigated as a treatment for posttraumatic hemorrhage, postpartum hemorrhage and prevention of surgical blood loss.

Diphenhydramine Overdose in the ED

Image Credit: Flickr Andrew Ranta

Author: Kaylinn Dokken, OMSIV
Western University of Health Sciences

You are just at the beginning of your shift when paramedics call in and notify you that they are bringing in a 35 year old female who reports that she took 3,000 mg of diphenhydramine in a suicide attempt. Her BP is 145/80, her pulse is 160 beats per minute (bpm) with sinus tachycardia on the monitor, and her respiratory rate is 24 breaths per minute. Upon presentation, the patient is disoriented, continuously writhing, and having intermittent myoclonic jerks. An initial EKG is obtained and is shown below.

Expanding the Differential: What Else Can an Elevated Troponin Signify?

Author: Shyam Sivasankar, MD
Stanford-Kaiser Emergency Medicine

Originally Published: Modern Resident, December-January 2015

We often underestimate the utility of modern laboratory technology—we become shortsighted and we forget that a lab value can tell us more than what we are naturally used to it representing. One such lab value is cardiac troponin.

Instinctively, we assume that an elevated troponin is a sign of a myocardial infarction (MI), but that is not always the case. Troponin is released by cardiac muscle fibers in the setting of irreversible cell injury.

Occasionally, we can be fooled into thinking that all chest pain with an elevated troponin is a definitive diagnosis of MI, but other life-threatening causes of chest pain such as pulmonary embolism (PE) or aortic dissection can also present with an elevated troponin. The ‘troponin leak’ from PE results from right-sided heart strain and from direct myocardial injury in dissection. Elevated troponin can also be seen in pericarditis (which can also present with ST segment changes), myocarditis, blunt chest trauma and arrhythmias. Patients who have suffered from cardiac arrest and undergone CPR can also have elevated troponin levels.

Clonidine Toxicity: A Brief Review

Image Credit: Flickr Pranjal Mahna

Author: Matt Rosen, MSIV
Georgetown School of Medicine

This post was peer reviewed.
Click to learn more.

Background:
Clonidine was once a popular antihypertensive agent, and while its use as a primary blood pressure agent has declined, it continues to have a role in hypertension management for some patients. Clonidine is also being used in other applications such as treatment of migraines, treatment of vasomotor symptoms associated with menopause or withdrawal, and in a number of pediatric applications such as pre-anesthesia, postoperative pain management, and panic/anxiety disorders.[1, 5]