Disaster plans must do the greatest good for the greatest number, preserve the medical infrastructure for the sickest and most injured patients and evenly balance medical care across the entire medical spectrum of observation and acute care. Multiple venues for observation, along with limited evaluation and treatment at off-site facilities (e.g. outside the hospital) with attention to an ethical and equitable distribution system for all patients will allow for appropriate, compassionate patient and family centered treatment of individuals including the special health care needs (SHCN) patients/patients with access and functional needs, and provide quality medical care. Plans made in advance, agreements across medical and community and state entities tailored to the unique disaster and in a tiered modular surge system including observation can facilitate the most appropriate distribution and best care possible for the most patients under the difficult situation and constraints of a disaster or pandemic.

This chapter discusses (1) the medical complexity and specialized subspecialty care that is part of the tertiary care hospital which may involve “complex” or “second level” units and (2) academic centers and the inclusion of education and research in academic centers.

Compared to hospitalization, the use of an observation unit (OU) can result in equal to or improved patient care, decreased length of stay, increased patient satisfaction, and lower cost of care and is an efficient and safe utilization of limited health care resources. Treatment of asthmatics in the OU allows time for administered corticosteroids to take effect and for other pharmacologic agents including inhaled short-acting beta-adrenergic agonists and anticholinergics, and magnesium to be administered. Initiation of controller/long-acting medications, patient education and assessment of social determinants of health can occur in the OU.

Patients with electrolyte abnormalities may be appropriate for the observation unit (OU) depending on the severity of the disturbance, the patient’s comorbidities, and the suspected etiology of the imbalance. Patients with potential for requiring life-saving interventions or prolonged treatments are better suited for inpatient admission. Abnormalities, both hyper (high) and hypo (low), of potassium, calcium, magnesium, sodium and phosphate may be treated in the OU.

Vaso-occlusive episodes (VOE) are the most common complication resulting from sickle cell disease (SCD) in adults. VOEs are caused by ischemic tissue injury as a result of occlusion of microvascular beds from abnormal sickle shaped red blood cells (RBCs). Individuals with SCD display a host of complications associated with micro and occasionally macro vascular occlusion, including stroke, leg ulcers, spontaneous miscarriage, and renal insufficiency. The acute pain crisis is the most common reason patients with SCD seek medical care in emergency departments (EDs). Due to the recurrent nature of acute pain crises, possible inadequate knowledge of health care providers about the disease, and the intensity of treatment needed, patients with VOEs may be undermedicated in the ED. This can lead to low patient satisfaction, low provider satisfaction, and increased cost of care. Through the use of an ED observation unit (OU) or clinical pathway, patients experiencing VOEs can be effectively managed to improve outcomes, improve satisfaction, and decrease cost of care.

Observation medicine and its dedicated units provide hospitals with a high quality, safe, and efficient space to provide care while avoiding increased costs. Observation units (OUs) positively impact inpatient capacity, reduce audits, and improve revenue capture making them a value-added asset for hospitals and their administrators. OUs can turn unprofitable admissions into profitable observation stays. Private and government insurance companies benefit from the structure and efficiency of OUs which provide care at an outpatient payment level that is far less than the payments for inpatient care. Furthermore, by freeing up acute care beds for undifferentiated patients within the waiting room, OUs alleviate strains on emergency department resources – a benefit to both physicians and patients. The medical and financial benefits of OUs, and their viability, ultimately requires the support of several key stakeholders including physicians, advanced practice providers, nurses, hospital administrators, payers and patients.

Hypoglycemic patients are often hospitalized for further management. Most of these patients can be successfully managed in an observation unit (OU). OU management includes determining the cause of the hypoglycemia, lab tests (basic metabolic panel and renal function, other tests as indicated), correction of the hypoglycemia, frequent monitoring of serum glucose, administration of medications including dextrose, glucagon, and occasionally octreotide, patient education, and at discharge adjustment of daily medications if needed.

Dehydration is a frequent diagnosis made in the emergency department (ED) and a common pathway in the observation unit (OU). Gastroenteritis and vomiting are two common causes of dehydration. Patients at the extremities of age are particularly vulnerable to dehydration yet still can be managed effectively in an observation setting. The evaluation of dehydration includes physical and laboratory assessment though both can be nonspecific. Management includes non-invasive versus invasive rehydration as well as electrolyte correction. The first-line therapy of intravenous rehydration is isotonic crystalloid solution. The management of dehydration in an OU is straightforward, typical and effective.

OU patients will be on track to better outcomes, reduced length of stay, all while reducing health care costs.

Management of transient ischemic attack (TIA) patients in an observation unit (OU) results in reduced risk for subsequent stroke, greater compliance with diagnostic evaluation, shorter length of stay, lower cost, decreased hospital overcrowding and ambulance diversion. OU management should evaluate TIA mimics, differentiate TIA from stroke, and detect high-risk pathologies that require immediate intervention and admission.

Hyperglycemia ranges from new onset diabetes to nonketotic hyperglycemia (hyperosmolar hyperglycemic state [HHS]) and diabetic ketoacidosis (DKA). The treatment goals in selected patients with DKA and HHS can be achieved in the observation unit (OU) and include frequent monitoring, IV fluids and insulin to correct hypovolemia, hyperglycemia, hyperosmolality, electrolyte abnormalities and in the case of DKA, correct the metabolic acidosis. For new-onset diabetics, medications can be started and education can be provided. The OU provides an opportunity to address related lifestyle and health issues that affect patient outcomes in diabetes; including diet, exercise, weight loss, and smoking cessation. Patients with elevated lipids can be started on statin therapy and those with established cardiovascular risk factors begin a daily aspirin. An OU stay allows for expedited consultation with endocrinology in select patients with poorly controlled diabetes, which has shown to improve quality of care.

Reflecting on the many changes, waivers, and flexibility provided during the COVID-19 Pandemic event, there are numerous lessons from the emergency management arena that may be applied to observation medicine. When considering geographic vs. non-geographic observation units, the use of tele-observation may be a practical option creating an observation unit distant from the emergency department. Here physician services required under Medicare may be substituted using independent licensed practitioners who keep directly in contact with the remote observation service physician using tele-health audio-video devices. Developing Job Action Sheets for key observation unit team members can outline immediate response actions and activities, documentation requirements, communication systems, and disposition determination guidance for admission, discharge, or continuing observation.

The key components mandatory for observation services: hospital site of service, acute care staffing, continuous care in outpatient setting, intensive managerial review and economical service are enumerated.

This chapter discusses the unique opportunities provided by an emergency department-based observation unit in a community hospital based in an urban area. These include the ability to pivot to specific unexpected needs such as a pandemic and providing focused care to a population of geriatric patients. In addition, these units are known to be cost effective and patient customer satisfiers.

Risk management is defined. Processes involved in risk management for the observation unit including care protocols, care team communications, discharge and follow-up care are identified. Tools that can be used for risk management include the plan–do–study–act (PDSA) and the I-CAN handoff.

Social medicine has two components: social determinants of health (SDOH) and issues that can serve as a direct cause of illness, injury, and death. Substance abuse and addiction, and interpersonal violence, are two examples. Many patients who present to the emergency department (ED) with social medicine issues often have a concurrent observable diagnosis for which they can be placed in an ED observation unit (OU), often with their social medicine protocol being secondary to their primary reason for observation. Often patients who present to EDs with complaints related to social medicine issues do not require admission, but discharging them may present a risk in terms of recidivism and repeat visits. ED OUs can provide value by allowing for the engagement of appropriate resources for patients with social medicine-related issues in a slower-paced setting that allows for a more detailed assessment as well as a warm handoff to specialty navigators.

Treatment for acute exacerbation of chronic obstructive pulmonary disease (COPD) in the observation unit (OU) include: bronchodilators, anticholinergic agents, corticosteroids, supplemental oxygen, antibiotics and stabilization and treatment of other medical conditions that may have been exacerbated or a contributing factor and hydration as needed. The bronchitis component of COPD is treated with antibiotics. Recommendation for smoking cessation should be made for those that continue to smoke. A COPD discharge protocol may include provision of prescriptions, a scheduled follow-up appointment and scheduled call backs.

During the COVID-19 pandemic, the small developing island of Barbados instituted measures to minimize the entry of COVID-19 into its lone public hospital. As part of this plan the emergency department formed a virtual observation unit to sort and manage potential cases pending the return of diagnostic investigations. This process was successful in keeping the hospital from being overrun in the pandemic.

The growth of observation units provides a unique opportunity to train residents in a controlled environment and teach them principles of providing sub-acute care beyond the emergency department.

Alcohol causes more harm than any other substance. Despite this, a large majority of patients with alcohol use disorder go untreated.  As emergency medicine providers, we are uniquely positioned to bridge this treatment gap.  As such, the observation unit (OU) can be an effective site to manage the consequences of alcohol use disorder (AUD) and initiate treatment.  This initiation in the emergency department OU has shown to be more effective than a simple referral. OU management may involve OU pathways for the treatment of mild alcohol withdrawal and alcohol intoxication. The OU allows time for initiation of treatment for the AUD including medications (e.g. naltrexone or acamprosate).

Syncope is a common presenting complaint to emergency departments, and can lead to costly and often fruitless inpatient hospitalizations. Observation units can be particularly helpful in the assessment of an unexplained syncopal event by providing a period of monitoring and a chance to obtain further testing in those patients who are not deemed low risk enough for immediate discharge and outpatient follow-up, nor high risk for adverse events. This chapter will discuss some of the tips and pitfalls in the assessment of the syncope patient and some of the traditional diagnostic options during the patient’s evaluation.