or tenderness that could suggest intra‐abdominal conditions associated with AMS such as ascites, or perforated or ischemic bowel.
Neurological
In addition to pupillary findings, any focal neurologic signs suggesting stroke or increased intracranial pressure should be noted. An unresponsive patient with focal neurologic signs or concern for elevated intracranial pressure (e.g., Cushing’s triad of hypertension, bradycardia, and irregular respirations) are especially concerning and may need rapid transport to a specialty center. Seizures or seizure‐like activity also cause altered mental status. Signs of ongoing seizure (fixed gaze, tonic‐clonic movements) or post‐ictal state (AMS with evidence of loss of bowel or bladder tone, tongue trauma) should be noted. Family or friends may be able to validate that the patient’s speech is not normal, providing evidence of altered content of consciousness. EMS personnel should screen for stroke using an established stroke scale, such as the Cincinnati Prehospital Stroke Scale, Los Angeles Prehospital Stroke Screen, or Melbourne Ambulance Stroke Screen [4–6]. To further guide patient care, assessment with a stroke screen that considers large vessel occlusion, such as the Rapid Arterial Occlusion Evaluation (RACE) scale for stroke, or the Stroke Vision, Aphasia, Neglect assessment, should be used in patients with signs of stroke to assist with transport destination decision‐making [7, 8].
Skin
The skin may be used to estimate temperature, which may be increased in infection or heat illness and decreased in cold exposure, dehydration, or alcohol or barbiturate overdose. Rashes potentially indicating infection or allergic reaction should be noted. Track marks consistent with needle injections and drug overdose should be checked for. Signs of a previous suicide attempt, such as healed wrist scars, may be apparent. The undifferentiated patient should be log‐rolled and examined head to toe to observe for transdermal drug patches, insulin pumps, dialysis access, petechiae, occult puncture wounds, and other subtle findings.
Historical and environmental clues
As the situation permits, EMS personnel should systematically obtain from the scene as much information about the patient as possible. Because the patient often cannot provide an adequate history, EMS clinicians should seek additional information from alternative sources, such as bystanders, family, and physical surroundings. Important questions include the patient’s baseline health and past medical history, current prescribed medications, the rapidity of the onset of the symptoms, and any complaints voiced or signs exhibited by the patient. One particularly useful question is whether the patient ever had a complete loss of consciousness or seizure‐like activity.
EMS personnel should search common locations such as bathrooms, medicine cabinets, bedrooms, nightstands, and kitchens for clues about underlying illnesses or possible ingestions. A medical alert bracelet or necklace should be sought. Other household members with similar signs and symptoms, or the presence of multiple patients with AMS, or the presence of sick or deceased pets may point to a toxic environmental exposure such as carbon monoxide poisoning.
If a drug overdose or poisoning is suspected, EMS personnel should gather further pertinent information, including the route of exposure, the type of substance involved, and the time and amount of exposure. Empty pill containers, liquor bottles, syringes, and other drug paraphernalia can greatly facilitate later treatment decisions. In most cases, overdoses will occur by ingestion. If the exact amount of exposure or ingestion is not known, personnel should try to establish the maximum possible quantity. They should also note any actions taken by the patient or bystanders, including the administration of any “antidotes.”
Initial management
The focus of a care protocol for the patient with AMS is to secure the ABCs and rapidly identify and treat reversible conditions. Care for the AMS patient is largely supportive, with evaluation and treatment of abnormal vital signs as noted above. In parallel, EMS clinicians should use the exam, history, and environmental clues to attempt to identify a specific cause or causes of AMS that could benefit from early treatment in the field with a specific remedy or antidote.
Presentations, etiologies, and treatments
The potential presentations and causes of AMS are extensive and complex. Although the definitive treatment for many of these problems may fall outside the scope of practice of EMS clinicians or the duration of the prehospital contact, the focus should be on identifying the primary cause or causes of AMS and beginning specific treatment in the field. As causes of AMS are identified in the individual patient, it is also necessary to determine whether a brief on‐scene interval and expeditious transport are required for time‐critical causes (e.g., STEMI, stroke, trauma), or whether the patient would benefit from further extended on‐scene management. A simple and frequently used mnemonic for the potential causes of AMS is AEIOU TIPPS (Box 15.1)
A major challenge with AMS patients is that they can be easily triaged into the AMS “not otherwise specified” protocol, while instead having a definable process. Dysrhythmia or hypotension associated with inferior MI may present with AMS as the predominant sign, and stroke patients with aphasia may be classified first as AMS. Indeed, all the various classes of shock may present with AMS yet may require different treatments.
Furthermore, patients with AMS may have multiple comorbidities that could be identified in the prehospital environment. For example, it is tempting to assume that a patient with seizures, who may be actively seizing or postictal, has an underlying seizure disorder. However, seizures may be caused by cardiac arrest (ventricular fibrillation), hypoxia, hypoglycemia, trauma, intracranial hemorrhage, stroke, infection, or drug overdose or withdrawal, all etiologies that can separately contribute to the patient’s AMS.
AMS patients with any of multiple etiologies may also be physically aggressive or combative, presenting a challenge as well as a risk to EMS clinicians. Patients with traumatic head injuries, those under the influence of either prescription or illicit drugs or alcohol, and those with medical emergencies such as hypoglycemia, postictal state, decompensated psychiatric disorders, and many others may be violent. The experienced EMS clinician will recognize that such a patient may have combative AMS due to an underlying medical condition, but that does not lessen the risks of physical harm to the patient or the clinician. Care should be taken to ensure both crew and patient safety. For additional information on managing the combative patient, refer to Chapter 58.
Box 15.1 Mnemonic for causes of altered mental status
A – Alcohol
E – Epilepsy, Electrolytes, Encephalopathy
I – Insulin (hypoglycemia)
O – Oxygen (hypoxia), Overdose
U – Uremia
T – Trauma, Temperature
I – Infection
P – Poisons
P – Psychiatric
S – Shock, Sepsis, Stroke, Space‐occupying lesion
Pediatric
