Accelerated therapeutic protocols targeting metabolic conditions are ideal for observation unit care. Because many conditions, such as hypokalemia and hyperglycemia, have little to no diagnostic uncertainty, the care in the unit is often straightforward. Additionally, some components of care for the endocrine condition may exhaust services, such as phlebotomy. Hence, this discussion focuses resource utilization and management considerations for the purposes of matching the level of care to the severity of the conditions. When carefully selected candidates are cared for in the observation unit, hospital resources can enable a safe, efficient hospital stay.
Key points
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Accelerated therapeutic protocols targeting metabolic conditions are ideal for observation unit care.
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Because many conditions, such as hypokalemia and hyperglycemia, have little to no diagnostic uncertainty, the care in unit is often straightforward.
- •
Some components of care for the endocrine condition may exhaust services, such as phlebotomy.
Accelerated therapeutic protocols targeting metabolic conditions are ideal for observation unit care. Because many conditions, such as hypokalemia and hyperglycemia, have little to no diagnostic uncertainty, the care in unit is often straightforward. To be sure, candidates for this level of care ideally have a more minor manifestation of their chronic condition, thus being sure about the overall severity of the current problem is paramount in the evaluation of these patients. Additionally, some components of care for the endocrine condition may exhaust services, such as phlebotomy. Hence, this discussion focuses on resource utilization and management considerations for the purposes of matching the level of care to the severity of the conditions. When carefully selected candidates are cared for in the observation unit, hospital resources can enable a safe, efficient hospital stay.
Hyperglycemia
Gerald Wilson is a 52-year-old man who lives in transitional housing. He complains of weakness and thirst. He says that it’s odd that he’s also making multiple trips to the bathroom at night to urinate. He has been rationing his insulin 70/30 mm Hg for it to last until his caseworker provides him with a new identification card. His card was stolen a few weeks ago, along with most of his belongings that he kept in a backpack. In the emergency department (ED) his vital signs are unremarkable. His laboratories are significant for a blood sugar of 469 mg/dL and an anion gap of 13.
Although treatment of hyperglycemia has a wide range of approaches in treatment of the acute phase, the Emergency Department Observation Unit (EDOU) performs well in delivering both rapid and standardized care. Currently, the number of EDOUs using hyperglycemia care pathways is largely unknown; but, in the author’s experience, many, if not most units do use some form of standardized approach to patients with hyperglycemia. Most EDOUs should be capable of treating most forms of hyperglycemia, from new-onset diabetes to mild or moderate diabetic ketoacidosis (DKA).
Patient Evaluation Overview
In the ED setting, patients with hyperglycemia can present in a variety of ways. Classically, patients with hyperglycemia report polyuria, polydipsia, and polyphagia, features that result from increased osmotic burden. Stabilization and evaluation for possible underlying causes of hyperglycemia is the cornerstone of initial management. Hyperglycemia still poses a large mortality burden, particularly in elderly individuals. Laboratory assessment of serum electrolytes will yield several pieces of important information used to direct further care. The typical laboratory findings of DKA and hyperosmolar hyperglycemic state (HHS) are listed in Table 1 . The presence of hyperglycemia should be the initial finding that prompts further evaluation. The level at which there should be concern for hyperglycemic emergencies is generally accepted as more than 250 mg/dL. However, recent data show that in the setting of known diabetes, the threshold should be closer to 300 mg/dL. When the serum glucose levels exceed this threshold, the anion gap (AG) and serum electrolytes are key to choosing which patients may benefit from the observation unit setting.
| Mild DKA | Moderate DKA | Severe DKA | HHS | |
|---|---|---|---|---|
| Arterial pH | 7.25–7.30 | 7.00–7.24 | <7.00 | >7.30 |
| Serum bicarbonate | 15–18 | 10–15 | <10 | >18 |
| Urine ketone | Positive | Positive | Positive | Small |
| Serum ketone | Positive | Positive | Positive | Small |
| Effective serum osmolality | Variable | Variable | Variable | >320 |
| Anion gap | >10 | >12 | >12 | Variable |
| Mental status | Alert | Alert/drowsy | Stupor/coma | Stupor/coma |
Observation Unit Care
A comprehensive discussion of the ED phase of management for hyperglycemia is beyond the scope of this article. There are a wide variety of reasonable approaches in the ED regarding the appropriate care provided and the duration of that care before disposition. There is no clear duration of time that dictates that a patient requires disposition to an inpatient service, an observation unit, or to home. Some conditions are amenable to direct placement in an EDOU from another outpatient setting, such as an office, thus bypassing the ED. The authors do not recommend this practice for patients with hyperglycemia. Even with normal vital signs, the patient may have profound electrolyte abnormalities that could significantly change the disposition and care needs of the patient. Patient selection for EDOU care is dependent on a thorough evaluation in the ED to rule out conditions that warrant a level of care beyond what is available in the EDOU. The following discussion assumes that a thorough ED evaluation has been completed.
Hyperglycemia without evidence of diabetic ketoacidosis or hyperosmolar hyperglycemic state
Most patients with simple hyperglycemia will have an easily identifiable cause for their elevated glucose. Often, this is due to an inability to access medications. Sometimes, there are more insidious factors responsible for hyperglycemia. These factors should be considered in all patients during the initial ED phase of care. The EDOU provider should still remain vigilant regarding other underlying etiologies, as patient conditions may evolve during their time under observation ( Box 1 ). A sample set of patient selection criteria for simple hyperglycemia is provided ( Box 2 ).
- 1.
Infection
- 2.
Infarct
- 3.
Infant
- 4.
Indiscretion (eg, cocaine use)
- 5.
Insulin lack
Inclusion Criteria
Blood sugar greater than 300 mg/dL and less than 600 mg/dL after emergency department treatment
Normal to near normal pH and CO 2 level
Readily treatable cause (eg, noncompliance, urinary tract infection, abscess)
Exclusion Criteria
New-onset hyperglycemia
Diabetic ketoacidosis
Obtundation (especially in the setting of hyperosmolar hyperglycemic state)
Social issues precluding continued outpatient management
In these cases of hyperglycemia with an easily identifiable cause without the complications of AG elevation and unremarkable electrolyte abnormalities, there are multiple ways to manage the elevation in blood sugar. Potential EDOU interventions are listed in Box 3 .
Intravenous hydration using crystalloids at 150 to 250 mL/h
Bedside glucose checks every 2 hours until level less than 300 mg/dL, then every 4 hours
Sliding-scale insulin
Treat precipitating causes
Diabetic counseling
Repeat serum electrolytes every 4 hours until laboratories stable
Most patients placed in an EDOU for simple hyperglycemia will be safely discharged home after a relatively short period of care. There is no established safe threshold for serum glucose. Many providers use the 300 mg/dL cutoff. Recently, a retrospective study by Driver and colleagues showed that the incidence of adverse events within 7 days of discharge is very low even with a higher range of glucose levels at discharge. Even so, it would not be common practice to discharge patients with blood glucose levels higher than 400 mg/dL. A basic set of discharge interventions is listed in Box 4 .
Home
Blood glucose less than 250 mg/dL (see discussion in text)
Resolution of symptoms
Normal vital signs
Tolerating oral fluids
Primary care follow-up in 48 hours
Patient education provided
Admit
Worsening symptoms
Development of diabetic keotacidosis or hyperosmolar hyperglycemic state
Inability to tolerate oral fluids despite appropriate management
Presence of social conditions that preclude safe home management
New-onset diabetes mellitus
Considerations to place a patient with new-onset diabetes in an EDOU include factors related to medication initiation or transition and appropriate education. In the adult population, most patients with new-onset diabetes will have type 2 diabetes, which may or may not require insulin. There are several ways to transition to insulin based on insulin usage in the EDOU setting. A general approach is to obtain an A1c initially and use it to determine if the patient may benefit from insulin at all. If above a threshold of 9%, the patient may benefit from a new insulin start (see the section “Insulin transitioning,” later in this article), as these patients are unlikely to ultimately achieve adequate control.
Diabetes education can be provided in a number of ways, depending on the resources of the hospital. Some institutions have a “diabetic educator” who handles much of the dietary and pharmacy-related questions for these patients. Other options include separating the pharmacy and diet education needs to work with a pharmacist and diabetic educator separately.
Diabetic ketoacidosis
Mild DKA (see Table 1 ) may be appropriate for placement in an EDOU, depending on the resources available and the comfort level of the EDOU providers with managing this condition. Moderate to severe DKA and any patient with significant clinical compromise are not appropriate indications for the observation unit setting because of the necessary intensity of service and low likelihood of discharge in 24 hours. Usually DKA is treated with a regular human insulin infusion until the AG is closed. However, there has been considerable experience with insulin aspart and lispro in successfully closing the gap and resolving DKA without requiring an insulin infusion. In mild DKA, the time to resolution is generally between 10 and 11 hours from presentation, making it ideal for an observation unit. Potential EDOU interventions for the treatment of mild DKA is provided in Box 5 , which lists a sample protocol for insulin administration adapted from these studies including the use of rapid-acting insulin.
During diabetic ketoacidosis
Hydration at 250 mL/h with NS or ½ NS
Electrolyte replacement of magnesium and potassium
Insulin aspart at 0.2 units/kg every 2 hours
Every 2-hour blood sugar level checks
Every 4-hour basic metabolic panel, β-hydroxybutyrate levels, and venous blood gas
When blood sugar is less than 250 mg/dL
Fluids changed to dextrose 5% ½ NS at 125 to 250 mL/h
Insulin decreased to 0.1 units/kg every 2 hours
Discontinue nothing by mouth status
As diabetic ketoacidosis resolves (criteria blood sugar <250 mg/dL, pH >7.3, anion gap <14, bicarbonate >18)
Stop intravenous fluids if tolerating an oral diet and has received home long-acting insulin
Transition to subcutaneous insulin
Abbreviation: NS, normal saline.
An important but sometimes overlooked element in the care of patients with DKA is the administration of subcutaneous long-acting insulin while the patient is still receiving an insulin infusion. The timing of this administration, whether at the time of diagnosis or toward the end of the requirement of insulin infusion, is a matter of debate. Current recommendations state that the insulin infusion should continue at least 30 minutes to 2 hours beyond the administration of long-acting insulin. Other care considerations include education of staff on feeding patients once blood sugars reach the 200 to 250 mg/dL range. In the experience of this author, patients treated for mild DKA are much more likely to become hypoglycemic as a result of overzealous treatment rather than to fail to have the AG close.
Insulin transitioning
Many patients will present to the EDOU on outpatient insulin regimens already and transitioning them back to their home regimen is generally simple. However, some patients with type 2 diabetes placed in an EDOU for a hyperglycemic emergency will only have been on outpatient treatment with oral antihyperglycemic agents. Certain patients with type 2 diabetes will benefit from outpatient treatment with insulin. There are emerging data that support starting insulin in patients with type 2 diabetes if their hemoglobin A1c level is greater than 9.5%. The EDOU can function to initiate this transition through careful patient selection and appropriate education. Other factors that may complicate patient selection for this indication are patient-level issues, such as their access to various resources.
Patients with appropriate access to outpatient resources who require insulin should be started on an optimal regimen that would be basal dosing of long-acting insulin along with a preprandial bolus dosing of rapid-acting insulin. The overall dosing is individualized, but a dosage of 0.5 to 0.8 units/kg per day having 50% divided between the basal dosing and preprandial dosing. Patients with limited access to outpatient resources can be started on a mixed insulin regimen. An advantage of these 70/30 regimens is the decreased cost and these have evidence showing beneficial safety profiles.
Special populations
There have been no clinical research trials on the management of DKA in patients with end-stage renal disease. The presence of this comorbidity leads to difficulty in interpretation of electrolyte levels due to the mixed acid picture that exists. This challenge coupled with the propensity for hyperkalemia and difficulty with fluid administration makes this a patient population that should be excluded from EDOU care. Patients with a history of congestive heart failure (CHF), regardless of the presence or absence of an acute exacerbation, also should be avoided for placement in the EDOU. These patients require judicious fluid administration and have a risk of developing acute pulmonary edema due to the fluid administered for the treatment of DKA. Further, there is well-documented increased length of stay for these patients beyond the usual observation stay period.
Hyperglycemia
Gerald Wilson is a 52-year-old man who lives in transitional housing. He complains of weakness and thirst. He says that it’s odd that he’s also making multiple trips to the bathroom at night to urinate. He has been rationing his insulin 70/30 mm Hg for it to last until his caseworker provides him with a new identification card. His card was stolen a few weeks ago, along with most of his belongings that he kept in a backpack. In the emergency department (ED) his vital signs are unremarkable. His laboratories are significant for a blood sugar of 469 mg/dL and an anion gap of 13.
Although treatment of hyperglycemia has a wide range of approaches in treatment of the acute phase, the Emergency Department Observation Unit (EDOU) performs well in delivering both rapid and standardized care. Currently, the number of EDOUs using hyperglycemia care pathways is largely unknown; but, in the author’s experience, many, if not most units do use some form of standardized approach to patients with hyperglycemia. Most EDOUs should be capable of treating most forms of hyperglycemia, from new-onset diabetes to mild or moderate diabetic ketoacidosis (DKA).
Patient Evaluation Overview
In the ED setting, patients with hyperglycemia can present in a variety of ways. Classically, patients with hyperglycemia report polyuria, polydipsia, and polyphagia, features that result from increased osmotic burden. Stabilization and evaluation for possible underlying causes of hyperglycemia is the cornerstone of initial management. Hyperglycemia still poses a large mortality burden, particularly in elderly individuals. Laboratory assessment of serum electrolytes will yield several pieces of important information used to direct further care. The typical laboratory findings of DKA and hyperosmolar hyperglycemic state (HHS) are listed in Table 1 . The presence of hyperglycemia should be the initial finding that prompts further evaluation. The level at which there should be concern for hyperglycemic emergencies is generally accepted as more than 250 mg/dL. However, recent data show that in the setting of known diabetes, the threshold should be closer to 300 mg/dL. When the serum glucose levels exceed this threshold, the anion gap (AG) and serum electrolytes are key to choosing which patients may benefit from the observation unit setting.
| Mild DKA | Moderate DKA | Severe DKA | HHS | |
|---|---|---|---|---|
| Arterial pH | 7.25–7.30 | 7.00–7.24 | <7.00 | >7.30 |
| Serum bicarbonate | 15–18 | 10–15 | <10 | >18 |
| Urine ketone | Positive | Positive | Positive | Small |
| Serum ketone | Positive | Positive | Positive | Small |
| Effective serum osmolality | Variable | Variable | Variable | >320 |
| Anion gap | >10 | >12 | >12 | Variable |
| Mental status | Alert | Alert/drowsy | Stupor/coma | Stupor/coma |
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