Emergency Medical Providers are programmed to look for the most dangerous or life
threatening disorders and treat them first. We are very good at identifying and intervening
anytime there is an issue with either airway patency, ventilatory insufficiency or perfusion
issues. While this approach serves the majority of our patients very well, this approach can
lead us down a path of overlooking more subtle causes of airway, breathing or perfusion
compromises. Take this situation for example: It’s a cool autumn evening and you are
dispatched to a local gas station to find a 48 yo female semi-responsive and breathing
shallowly in the bathroom. Her pulse is very slow, her breathing is shallow and ineffective, and
she feels cool to the touch. What are your first inclinations to what may be causing her current
condition? Substance use? Opiates? Hypothermia? Cardiac condition? Hypoglycemia? While
all or any of these differential diagnoses may be correct, how many of us would think about an
endocrine disorder, such as hypothyroidism, as one of our initial working diagnoses?
Endocrine emergencies are often overlooked or go unnoticed in the prehospital setting
because their symptomology often mimics more common medical emergencies that we
encounter in the field.
The endocrine system works thousands of times a minute in an attempt to maintain
homeostasis within the body. It regulates body systems to maintain adequate perfusion,
oxygenation, acid/base balance, blood sugar regulation, core body temperature, growth and
development to name just a few. Hormones are the major chemical mediator of the endocrine
system. Hormones are transmitted throughout the human body via the circulatory system.
Problems pertaining to the endocrine system arise when not enough (or too much) of a
hormone is secreted, adequate amounts of a hormone are secreted but the receptor sites on
the target organ are inadequate or non functional or adequate amounts of a hormone are
secreted, but it isn’t delivered to the target organ due to hypo perfusion. Endocrine
emergencies often are a diagnosis of exclusion. Only after more common conditions that
mimic the signs and symptoms are ruled out do providers start looking for endocrine related
issues. The endocrine system was largely misunderstood until the late 1800s to early 1900s.
The hypothalamus is considered the “brain” of the endocrine system as it is responsible
for processing incoming impulses from the nervous system and secreting specific hormones to
either the pituitary gland or to the body itself in response to the information it has received. It is
an almond sized gland, located deep in the lower center of the brain, just above where the
brainstem. The hypothalamus works second to second to maintain body homeostasis but it
also is responsible for our “fight or flight” response to perceived or actual threats to our body.
The “Stress Response” side of the hypothalamus releases hormones such as Corticotropin,
Anti-diuretic hormone (ADH) which causes the pituitary gland to release adrenocorticotropin
hormone (ACTH). ACTH causes an increase in the release of cortisol and androgen into the
body to prepare it for the perceived or actual insult. The “Metabolism Response” side is the
portion of the hypothalamus that is responsible for regulating the day to day metabolism and
growth and development. Thyrotropin Releasing Hormone (TRH) is released by the
hypothalamus to the pituitary gland which, in turn, releases Thyroid Stimulating Hormone
(TSH). TSH then is transported via the circulatory system to the Thyroid gland which in turn
increases the body’s metabolic rate by releasing the hormones T3 and T4.
The endocrine system regulates hormone production and release via a negative
feedback loop system. It works similar to the thermostat in a home. Let’s take the
hypothalamus and its Metabolism Response side and how it works. Once an impulse is
received from the afferent nerve pathways of the central nervous system that metabolic rate
needs to be increased, the hypothalamus releases TRH into the pituitary gland which then
releases TSH into the bloodstream. Once the hormone TSH arrives at the thyroid gland, it
releases T3 and T4 which increases overall metabolic rate. Once the nervous system notices
an overall increase in metabolic rate, it sends another message to the hypothalamus to slow
down the release of TRH to the pituitary gland which then decreases the amount of TSH it
releases. This decrease in the release of TSH into the blood stream then causes the thyroid
gland to release less T3 and T4 which will slow the body’s metabolic rate.