The unconscious patient can be a challenge in the prehospital setting, where it is not always apparent or obvious what is causing the patient to be unconscious. There is always the potential that the patient is critically ill or injured and it is important to try to anticipate the potential cause of unconsciousness. Following is an overview of select causes of unconsciousness.
Acute Alcohol Intoxication
The amount of alcohol needed for a patient to become unconscious will vary with each case. Contributing factors include the volume of alcohol consumed, the rate of consumption, if the alcohol was ingested on an "empty stomach" and the individual's tolerance to alcohol. It may be reported that the patient was "binge" drinking, which is often associated with consuming an excessive amount of alcohol in a relatively short period of time.
Patients who are taking insulin to manage their diabetes may have taken an excessive amount of insulin resulting in hypoglycemia. This can occur intentionally or accidentally. The patient may also be taking more than one medication that is intended to assist in maintaining a glucose level within a certain range. If the medications are administered incorrectly or out of normal sequence with a schedule, it is possible for the patient's blood glucose level to drop very quickly to an acutely low or abnormally low level and the patient may lose consciousness. Left uncorrected, hypoglycemia, or low blood sugar, can have serious consequences for the patient.
An individual may become unconscious following excessive consumption of a prescribed or over-the-counter medication or as the result of overdosing on a "street" drug, such as heroin. The list of possible scenarios that might be involved in a drug overdose situation is extensive. In some cases it may be unclear as to what drug/medication was taken, when it was taken, or how much was ingested. As an EMS provider, you should recall that routes of ingestion and drug forms vary. Common routes of ingestion include oral, nasal, intravenous and smoke inhalation. Drug forms can include pill, powder, fluid and drugs combined with other substances like a paste or other solutions. Depending on the situation, it might not be possible to determine which drugs are involved until the patient can be evaluated in an emergency department.
In the prehospital setting, in either blunt or penetrating trauma cases, it is not always possible to determine the specific injury or injuries involved. It is, however, essential that you are able to quickly recognize that the patient has a serious injury that may be causing unconsciousness. Examples include hypovolemia from internal and external hemorrhage, organ rupture, injury to the central nervous system (brain and spinal cord) and massive chest injuries. Management of the unconscious trauma patient may be limited in the prehospital setting, as surgical intervention may be necessary. The unconscious trauma patient should always be considered a candidate for a trauma center until proven otherwise.
While some causes of unconsciousness, such as a gunshot wound to the head, may be obvious, psychiatric causes or emergencies may be subtle. In suspected or confirmed cases of psychiatric disorders combined with unconsciousness, you will need to carefully and thoroughly assess the patient. If witnesses or bystanders are available, try to elicit a thorough history of events and ask specific interview questions. This may prove to be invaluable in assisting with a treatment plan. Examples of interview questions, which can be applied in almost any unconscious patient encounter, include: Has the patient been unconscious before? What was the cause? Could substance abuse or trauma be involved? Does the patient have any additional underlying medical conditions? What was the patient doing prior to becoming unconscious?
An acute stroke can result in unconsciousness for any patient. Signs and symptoms will vary based on factors like the nature and location of the stroke. As with any unconscious patient, the patient's underlying health will also be a factor. Stroke can be caused by ischemic cerebral events as well as hemorrhagic events. In the prehospital setting it is not possible to determine the type or location of a stroke when the patient is unconscious.
An infection can result in unconsciousness and may present subtly. EMS may be called to assess an individual who appears lethargic, excessively tired or perhaps "not normal." In these situations, a thorough medical history and patient assessment are important. Subtle findings like febrile skin, tachycardia and tachypnea may be present. The presence of additional injuries, such as open infected wounds, should also be noted. The patient with a systemic infection may require intensive care that exceeds the scope of prehospital care.
When a patient is unconscious, a thorough assessment will be invaluable when attempting to identify a possible cause. A detailed assessment will also assist you in developing a potential treatment plan. Treatment of the unconscious patient will vary with each situation. Providers should always focus on supporting the patient's airway, breathing and circulation, and supplemental oxygen should be administered. Additional treatment, such as establishing an intravenous line and administering medication, should be considered and may be guided by local protocols. In cases where trauma is suspected or confirmed, cervical spine precautions should be taken. Hospital destination will be influenced by a variety of factors, including if the incident is due to a medical or traumatic event.
1. Chapleau W, Burba A, Pons P, Page, P. The Paramedic. Boston, MA: McGraw-Hill, 2008.
2. Hubble M, Hubble J. Principles of Advanced Trauma Care. Albany, NY: Delmar Thompson Learning, 2002.
3. Pons P, Markovchick V. Prehospital Emergency Care Secrets. Philadelphia, PA: Hanley & Belfus, 1998.
Paul Murphy, MSHA, MA, has administrative and clinical experience in healthcare organizations.