Diagnostics in the Unconscious Patient

eight to twelve; mild impairment is a GCS of thirteen or more. Things that impact the scoring without being from a CNS source is the presence of a facial injury that prohibits speech or the presence of an intubated patient that, by definition, cannot speak.

The GCS is a good scale for adults but is not a good scale for semi-conscious children under the age of thirty-six months. Using the adult GCS would yield abnormal test results in even healthy children because they have limited speech. In such cases, there is a pediatric GCS scale used instead for children under the age of three years.

Diagnostics in the Unconscious Patient

The ultimate goal in dealing with the unconscious patient is to identify the underlying cause and treat it. There is no true diagnostic help in stating that the patient is “unconscious” because a wide variety of things could be causing what looks like roughly the same illness. This is where the diagnostic skills of the practitioner are important.

There are three major diagnostic categories that could result in a rapid decline into death in a comatose patient. These include cardiac arrest, airway obstruction, and apnea. These can easily be assessed by checking for a pulse, assessing the degree of spontaneous respirations, and checking to make sure air is moving (which doesn’t require a stethoscope necessarily). These are quick and easy evaluations that can be done in a few seconds. It is important to open the airway manually with a head-tilt maneuver or a jaw-thrust maneuver (or an oral or nasal airway). The unconscious patient may not be able to maintain an open airway but this is easily remedied.

There are three things that could result in death within a few minutes to a half an hour. These are not as serious as those listed previous to this but still can result in an early death. These include the patient with an overdose, one with hypoglycemia, and one with increased intracranial pressure and imminent herniation. For this reason, getting a blood sugar is crucial in any unconscious patient as is a quick and focused initial survey.

What should be included in a quick primary survey? These things include the following:

• Pupillary reflex—assesses intracranial pressure • Corneal reflex • Extremity movement • Muscle tone and posturing • Vital signs • Capillary refill • Abdominal palpation • Overall trauma assessment—looking for obviously traumatized body parts

This type of evaluation takes only about a minute and can lead to the first treatment decision to be made in the care of the unconscious patient. This means that, within a minute, about three things could be diagnosed and treated:

1. Hypoglycemic coma: Give one to two amps of intravenous D50W. This will not hurt the patient who is not hypoglycemic but will save the life of a patient severely affected by low blood sugar. 2. Opioid syndrome: Give the patient a dose of intravenous naloxone. This will not hurt the patient who does not have opioid syndrome but will save the life of a person with an opioid overdose. 3. Herniation syndrome: Elevate the head of the bed, intubate the patient, hyperventilate, and give IV mannitol. This will quickly save the life of a head injury patient if done before the herniation actually happens.

If these things are not a part of the differential diagnosis, there is still a list of things that could kill the patient within the first ten to fifteen minutes of their evaluation. These things can usually be looked out for in the primary survey and include the following:

• Aortic dissection or rupture • Myocardial infarction • Hyperkalemia • Anaphylaxis • Hypotension • Arterial blood gas abnormalities

As these things sometimes need more advanced testing than a simple survey, it is a good idea to go beyond the simple survey and do an arterial blood gas measurement and a basic metabolic panel, which will usually involve repeating the blood sugar level, which should be done by means of a glucometer as soon as possible after encountering an unconscious person.

Airway should continually be assessed and, unless the patient awakens quickly, decisions around making a more stable airway should be undertaken—even before an IV is established. Diagnostically, an EKG and an ultrasound device should be the first tests undertaken. The EKG can rule out an MI or arrhythmia, while an ultrasound can evaluate the abdomen and the aorta.

As the above things are placed into or out of the differential, treatments can be started. Besides oxygen, D50W, and naloxone, which are routine things to start ASAP, the primary survey can lead to several different treatments. Evidence of hypotension can lead to an urgent fluid bolus, followed by blood products. Anaphylaxis symptoms suggest the idea of giving epinephrine. The

EKG can suggest an arrhythmia or electrolyte disturbance, which might prompt the giving of calcium gluconate boluses empirically.

The next several things in the differential diagnosis of the unconscious patient involve a group of things that may still kill the patient but won’t generally kill the patient for a few hours. These include the following:

• Disorders of metabolism, such as diabetic hyperglycemic disorders, hyponatremia, adrenal insufficiency, and thyroid storm • Severe abdominal injuries or a ruptured viscus with septicemia • Necrotizing fasciitis, which can be on any part of the skin • Status epilepticus • Alcohol withdrawal syndrome • Intracranial bleed • Sepsis/septicemia

Most patients need a CT scan of the head, abdomen, or chest as part of the entire workup. For this reason, they should be completely resuscitated with a definitive airway and relatively stable vital signs. This should be done and blood work should be drawn and may be pending at the time of the CT scan. Antibiotics should be started empirically on everyone with acyclovir started only if viral encephalitis is felt to be the cause. Care should be made to recognize non-convulsive status epilepticus as this requires the same treatment as the actively convulsing patient.

The first few things listed above include those things that can quickly kill the unconscious patient and need urgent ruling in or ruling out. After this is done, a complete differential diagnosis can be made of the various causes of unconsciousness. This involves a much longer list and includes things that will shortly kill the patient and things that may take hours to days to be deadly if not treated. The full differential includes the following:

• Alcohol poisoning/overdose • Metabolic acidosis • Hepatic encephalopathy with hyperammonemia • Arrhythmia • Endocrine disorder like myxedema or adrenal crisis • Electrolyte abnormality • Anoxic encephalopathy • Septicemia/severe infection • Hypoxia • Drug overdose • Uremic encephalopathy