Introduction

For prehospital providers, there are several causes for the patient with altered mental status or being unconscious to include the mnemonic AEIOU TIPS for Alcohol and acidosis, Endocrine, Epilepsy, Electrolytes, Encephalopathy, Infection, Opiates, Overdose, Uremia, Underdose, Trauma (head injury and blood loss), Insulin, Poisoning, Psychosis, Stroke, Seizure, and Syncope. Hypoglycemia, or low blood glucose level, is one of the most common causes of altered mental status for patients with and without diabetes. Estimates are that 1 to 2 percent of prehospital encounters and 7% of refusals are for hypoglycemia.[1][2]

Diabetes mellitus often referred to as "diabetes" or "sugar" by laypeople is the most common endocrine disorder where the body does not either produce enough insulin or has a resistance to the circulating insulin, and is characterized by high blood sugar levels over prolonged periods. The three main types of diabetes are type I (previously referred to as insulin-dependent diabetes mellitus (IDDM) or juvenile-onset), type II (formerly referred to as non-insulin-dependent diabetes mellitus (NIDDM) or adult-onset) and gestational.[3] Insulin is an anabolic hormone produced in the beta cells of the pancreatic islets. The primary function of insulin is to regulate the metabolism of carbohydrates, protein, and fat through the absorption of glucose sugar from the blood into the liver, fat, and skeletal muscle cells. These small glucose molecules are then converted into larger molecules and stored for later usage. 

Type 1 Diabetes Mellitus (T1DM) [4]

This condition is commonly referred to as insulin-dependent diabetes or previously as childhood/adolescent-onset diabetes. It accounts for approximately 5% to 10% of all cases of diabetes. It can be related to the autoimmune destruction of insulin-producing beta cells in the islets of the pancreas from different causes, including genetic susceptivity, viral illness, toxins or alcohol-induced pancreatitis, or some dietary factors.  The age group affected is usually children and adolescents, but adults can develop T1DM.  As the name "insulin-dependent" implies, it requires the administration of subcutaneous insulin via intermittent injections or pump infusion.

Type 2 Diabetes Mellitus (T2DM) [4][5]

This variant is commonly referred to as non-insulin diabetes or previously as adult-onset diabetes.  It accounts for approximately 90% of all cases of diabetes.  It is related to the desensitization of insulin/insulin resistance (response to insulin becomes diminished) in various tissues. Initially, there is an increase in insulin production, but this decreases over time. T2DM most commonly presents in persons older than 45 years, but it increasingly occurs in children, adolescents, and younger adults due to rising levels of obesity, physical inactivity, and energy-dense diets.

Gestational Diabetes Mellitus (GDM)

Hyperglycemia first detected during pregnancy is classified as gestational diabetes mellitus (GDM). Although it can occur anytime during pregnancy, GDM generally affects pregnant women during the second and third trimesters. According to the American Diabetes Association (ADA), GDM complicates 7% of all pregnancies. Women with GDM and their offspring have an increased risk of developing type 2 diabetes mellitus in the future. 

Types of Therapies [6]

Therapy for hyperglycemia is dependant upon how much insulin the body is producing, or how well that insulin that is produced is working.  The majority of patients with T2DM will be on an oral type of medication.  Patients with T1DM will be on a combination of either long-acting insulin with short-acting as a sliding scale, intermediate-acting insulin with short-acting insulin as a sliding scale, combination premixed insulin, or be on an insulin pump.

Hypoglycemia 

One of the public health concerns for diabetes mellitus and unintended complications for the reduction in blood glucose levels is hypoglycemia.[1][7][8] Hypoglycemia, by definition, is a plasma glucose concentration below 70 mg/dL, with most patients not having signs or symptoms until the plasma glucose concentrations drop below 55 mg/dL.[9]  Low plasma glucose concentration that requires assistance from another individual qualifies as severe hypoglycemia, and by context, all EMS encounters fall into this category.[1][10]  There has been an increase in morbidity (poor quality of life, series falls or car accidents, dementia, and hospitalization) and mortality related to severe hypoglycemia.[1] 

Based upon 2015 data from NEMSIS, prehospital activation for diabetes-related cases accounts for about 2.3% of all activations, with the primary EMS encounter being hypoglycemia.[11] Patients experiencing severe hypoglycemia or other diabetes-related concerns typically reach out for help by calling 911 who may dispatch a fire department or EMS agency depending on the jurisdiction. Care is then provided by the first on scene provider who may be an emergency medical technician (EMT) intermediate or advanced emergency medical technician (IEMT or AEMT) or paramedic. Treat and release versus transport of patients with hypoglycemia by EMS providers depends on the clinical guidelines or protocols from either the state or regional level by medical directors. It is important to understand that patients with severe hypoglycemia are at a higher risk of having complications related to the hypoglycemic state.  Villani et al. indicated that approximately 50% of patients with severe hypoglycemia required transport to the hospital, and of that group, 41.3% were admitted to the hospital.[12][13][14] 

One of the first studies on the topic of treating and releasing hypoglycemic patients in the field was "Development and Evaluation of Criteria Allowing Paramedics to Treat and Release Patients Presenting with Hypoglycemia: A Retrospective Study" published in Prehospital and Disaster Medicine in 1991.   Their study design proposed five criteria that would allow for appropriate release that would not require additional treatment from prehospital providers to include:

1. The patient has a history of type 1 or type 2 diabetes.
2. Blood sugar prior to treatment is below 4.4 mmol/L or 80 mg/dL.
3. Blood sugar after treatment is equal to or greater than 4.4 mmol/L or 80 mg/dL.
4. The patient has a normal mental status within 10 minutes of treatment. 
5. The patient does not have any other complicating factors that required ED evaluation to such alcohol, chest pain, dyspnea, injuries related to falls, and/or renal dialysis.

A 2016 study by Rostykus et al. reviewed prehospital clinical guidelines for hypoglycemia in 185 EMS agencies in the United States.  It revealed that less than half allowed for non-transport of patients with hypoglycemia after the low plasma glucose level was corrected.[15] A study by Moffet et al. looked at hypoglycemic patients treated by EMS in Alameda County from 2013 to 2015 and found that the transport rate was 13.5%. The demographic trends for those non-transported patients were adult patients < 60 years of age, males, finger stick blood glucose levels > 60 mg/dl, and EMS arrival times between 1800 and 0600.[1]

Issues of Concern

Patients with diabetes have an improvement in the quality of treatment and prognosis with proper education and training of prehospital providers. This training depends on the specific level of education of the prehospital providers (EMT, Advanced EMT, Paramedic, etc.). There are also state variations on the scope of practice, and within the United States of America, prehospital agencies have to have a CLIA waiver to perform blood glucose monitoring. Type 1 diabetic patients who have received previous education and who had symptomatic hypoglycemia at the scene were safe to treat with the potential of release at the scene after the patient was no longer symptomatic.[11] Patient with non-insulin dependant diabetes on oral hyperglycemic medications, specifically sulfonylureas (chlorpropamide, glipizide, glimepiride, glyburide, tolazamide, and tolbutamide) that act by stimulating the beta cells of the pancreas to release insulin, have the potential of continued hypoglycemic states even after the administration of dextrose containing solutions.  

Clinical Significance

Prehospital treatment for hypoglycemia depends upon the level of training for the provider.  2018 National EMS Scope of Practice Model for EMS delineates the ability of emergency medical technician level and above to perform blood glucose monitoring. In the United States of America, prehospital providers have to obtain a Clinical Laboratory Improvement Amendments (CLIA) waiver to perform blood glucose testing.[11]

A review of the literature in prehospital treatment and release of hypoglycemic patients appears to be safe with the caveat that the patient did not have a severe hypoglycemic episode.[2][12][13][14] The National Association of State EMS Officials (NASEMSO) released in February 2019 the National EMS Scope of Practice Model, which delineates the roles for EMS providers with treating patients with hypoglycemia. Emergency Medical Technicians (EMTs), Advanced EMTs, and Paramedic providers are allowed to perform blood glucose monitoring and administer oral glucose for suspected hypoglycemia.  Advanced EMTs and Paramedics under the National Scope of Practice are allowed to initiate peripheral intravenous catheters as well as intraosseous catheters. They are both also allowed to administer non-medicated IV fluids such as those containing dextrose solutions in the treatment of hypoglycemia, but the state scope of practice on this may be variable. Administration of glucagon intramuscularly, a peptide hormone that stimulates the release of glucose, by Advanced EMTs and Paramedics is may also be dependant on the scope of practice for individual states.

The National Association of State EMS Officers (NASEMSO) National Model EMS Clinical Guidelines updated on January 5, 2019, has specific treatment disposition parameters for prehospital providers on the release without transport of the hypoglycemic patient requiring dextrose or glucagon administration.  Obtained from https://nasemso.org/wp-content/uploads/National-Model-EMS-Clinical-Guidelines-2017-PDF-Version-2.2.pdf to include specifically:

1. Disposition
   1. If hypoglycemia with continued symptoms, transport to the closest appropriate receiving facility.
   2. Hypoglycemic patients who have experienced a seizure should be transported to the hospital irrespective of their mental status and therapeutic response.
   3. If symptoms of hypoglycemia resolve following treatment, release without transport should only be a consideration if all of the following are true:
      1. Repeat glucose measurement is greater than 80 mg/dL.
      2. The patient takes insulin or metformin to control diabetes.
      3. The patient returns to normal mental status, with no focal neurologic signs/symptoms after receiving glucose/dextrose.
      4. The patient can promptly obtain and will eat a carbohydrate meal.
      5. The patient or legal guardian refuses transport, and EMS providers agree transport not indicated.
      6. A reliable adult will be staying with the patient.
      7. No significant co-morbid symptoms exist, like chest pain, shortness of breath, seizures, intoxication.
      8. A clear cause of hypoglycemia is identifiable (e.g., missed meal).