Grand Rounds Recap - 1/21/15

Evidence-Based Emergency Medicine: Accidental Hypothermia with Drs. Mudd & Riddle

Grading the Severity of Hypothermia

• Mild hypothermia is defined as 32-35 °C and symptoms include confusion and diuresis
• Moderate hypothermia occurs from 28-31°C and is associated with lack of shivering, atrial arrhythmias, and worsening changes in mental status (including paradoxical undressing)
• Severe hypothermia happens when core body temperature is less then 28 °C and is associated with coma, significant decreases in metabolism, and a very low threshold for V-fib

Epidemiology of the Problem

• Hypothermia can be seen in patients throughout the year and while cases of mild/moderate hypothermia increase in winter, mortality occurs in cases throughout the year
• Risk factors for hypothermia include environmental exposures, extremes of age, alcohol use, trauma, water immersion, and infection
• In the US there are between 650-1500 case fatalities annually from hypothermia with a mortality rate of 40%

Keep in mind when diagnosing hypothermia that most standard thermometers are only rated to ~34 degrees so be sure to check if the thermometer your using will actually be effective

• Bladder and esophageal temperature monitors seem to be equally reliable for monitoring core temperatures

By Jer5150 (. ') [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Osborne waves (positive deflections after the QRS) on EKG can be associated with hypothermia but are neither sensitive nor specific

Prognostication in these patients, especially those that arrest, is incredibly difficult as there have been case reports of patients with potassium levels of greater than 12 surviving neurologically intact

• In one retrospective study the only significant prognostic factor was the use of pressors on admission to the ICU

Management of hypothermia is primarily focused on rewarming and can start even in the pre-hospital setting

• Be gentle handling these patients as the V-fib (that can be particularly refractory) threshold is so low that even simple movement can trigger this
• Treatment is a continuum depending on the severity of hypothermia from passive warming with warm blankets to active warming through forced air devices (i.e. Bair Huggers) and warm IV fluids to invasive warming with intra-cavitary warm water lavage
• Seriously consider intubation early in these patients and one retrospective review of >100 intubations in hypothermic patients did not show any increased rates of complications
• Invasive rewarming can occur by placing warm fluid in nearly any body cavity, but the suggested method is using a right-sided hi/lo dual chest tube set-up to connect to a volume infusion device (i.e. Level 1 transfuser)
• ECMO may be effective for this but the evidence is still accumulating
• There are case reports of people surviving neurologically intact after hypothermic arrests to as low as 12 °C, hence the old adage, "you aren't dead until you're warm and dead"
• AHA recommends that compressions should be avoided in patients without a palpable pulse with an organized rhythm on monitor - often they are having adequate perfusion for their metabolic rate and the pulse is particularly hard to palpate in hypothermic patients (though disorganized rhythm, such as V-fib, compressions should be initiated)
• Consider use of advanced monitoring techniques in the pulseless hypothermic patient with organized rhythm, such as end-tital CO2 and arterial lines

Hypothermia in trauma is particularly concerning as it is one arm of the "triad of death" as it can worse acidosis, coagulopathy, and shifts oxygen dissociation curve to the left leading to decreased oxygen delivery to the tissues

By en:User:Cburnett [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons

• Hypothermia in trauma patients is often accidental due to environmental exposures and can be iatrogenic
• In one study trauma patients with temperatures of less than 35 °C had a mortality rate of ~50% and those with core temps of less than 33°C had a mortality rate of greater than 80%!
• Be vigilant to watch out for hypothermia in the trauma patient (always remember to get a complete set of vitals) and be aggressive about rewarming with active and passive methods as even the mild hypothermic traumas have significant mortality

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Leadership Curriculum: Communication Styles & Differences

We all communicate differently and tailoring your style of communication to your audience is a skill set vital to any effective leader

Consider the communication you gravitate towards but also be cognizant of other styles and how to best communicate with them to achieve your goals

A great deal influences our own communication styles including our upbringing, culture, and gender

One continuum of communication styles is focused on gender communication, where masculine communicators tend to be more direct with their language using more declarative statements, project self-confidence by positioning themselves to be able to one up colleagues, and more likely use "I" in their conversations.  Meanwhile feminine communication styles tend to emphasize harmony and building rapport, share credit through utilizing the pronoun "we" and downplay certainty in their speech patterns

Whenever communicating keep your audience and the context central in your mind and utilize your language to leverage your leadership of the situation