The observation unit (OU) is an alternative to hospitalization for selected patients and allows the clinician to assess patient response to therapy, and to detect any other hidden pathology or complications. In the OU, management includes IV antibiotics, antiemetics, IV fluids, and treatment of fever and pain. By reducing the number of hospital admissions for acute cystitis and pyelonephritis there can be significant cost savings for both the patient and the health care system.

Optimal care for the abdominal pain patient includes early diagnosis, urgent surgical consultation when required, and appropriate imaging and disposition. In some cases, patients may require serial re-evaluations, nonoperative treatment and /or further diagnostic workup to determine the severity of their illness and whether they require further inpatient care or can be safely discharged home with follow-up. Emergency department observation units have been shown to provide efficient and effective care while being more cost-effective compared to inpatient care

Hospice is under-utilized, especially for non-cancer illness deaths. People from communities of color are less likely to receive hospice services. Identifying patients with terminal illnesses in the emergency department (ED) and initiating the hospice discussion or process could be one way to rectify this. Most patients have an ED visit within the last 6 months of life. This suggests that EDs are missing opportunities to offer hospice care to patients. When hospice is under consideration, many EDs admit patients to arrange hospice, but this is not necessary. Transition to hospice care can be coordinated out of the ED or ED observation unit (OU). Admission for hospice placement is rarely necessary, and in one ED study, 89% of ED patients qualifying for and wanting hospice had less than a 2-day stay. Creating an ED to hospice protocol for your OU could improve the provision of patient-oriented care and decrease strain on hospital resources by decreasing unnecessary admissions.

Trauma is one of the leading global causes of mortality. In spite of more liberal use of CT scans, some patients will still have occult injuries and require a short period of observation and may need treatment of pain, etc. Emergency department observation units (ED OUs) have been used for the short-term management of trauma patients since the 1980s. OUs have proven to be a cost effective and safe alternative to inpatient admission for patients who need short-term management of their injury. OUs were found to decrease length of stay, increase efficiency, and decrease the utilization of resources.

This chapter provides a general overview of the disease process of atrial fibrillation beginning from the pathophysiology of the disease to the financial impact on the health care system, includes up to date guidelines on the management and treatment of atrial fibrillation, and demonstrates the impact of an emergency department observation unit in the care of patients with atrial fibrillation.

The treatment of pain and painful complaints in the observation unit (OU) is dependent on appropriate assessment, frequent re-assessment, recognition of any underlying medical conditions, and individualized treatment. Patients referred for observation should meet OU criteria. OU protocols should include provisions for the regular assessment of pain. In addition to non-geriatric adults, special populations including pediatric patients and the elderly, with painful conditions may be managed in the OU. Specific conditions that may be managed in the OU include acute low back pain, acute exacerbation of chronic pain, and the pain of malignancy.

We identified three centers in Saudi Arabia that implemented observation units (OUs). The presence of an OU helps with patient flow, reduces overcrowding, enhances patient care, safety and experience, and improves daily key performance indicators. Following this chapter, the authors’ own organizations are keen to develop observation units.

Poisoned patients who present to the emergency department often require a period of observation to determine their ultimate disposition. Most poisoned patients are able to be discharged within 24 hours, which makes them good candidates for observation unit (OU) admission. Data suggests that clinicians using well-defined protocols can safely manage poisoned patients in the OU. Benefits of OU care for this patient population include earlier involvement of multidisciplinary teams, shorter length of stay, conservation of resources and potential cost-savings. Pediatric poisoned patients in particular are excellent candidates for OU protocols. Multiple agents have been managed in the OU, such as acetaminophen, benzodiazepine, carbon monoxide, stimulants, opioids and various envenomations. OU protocols are not limited to single agent ingestions. OUs may also be used for buprenorphine initiation for the opioid addicted patient. The most effective protocols utilize the expertise of medical toxicologists to help risk stratify appropriate patients for OU care. With well-designed protocols, the poisoned patient can be effectively and safely managed in the ED OU.

Efficient and effective utilization of an observation unit (OU) requires the medical director to actively monitor key metrics of OU performance. The medical director should have use of reports or dashboards that can indicate unit census, length of stay, and inpatient conversion percentage. OU patients/bed/day is a useful measure of occupancy. In addition, the medical director should have an idea of how many patients go to the OU as a percentage of emergency department census and total hospital observation cases. These data can be used by the Medical Director to make changes to optimize OU utilization and throughput.

Observation medicine in New Zealand has grown considerably in the last decade, driven by the shorter stays in emergency departments health target and the growth of emergency medicine as a specialty. Evidence that the growth of this service has mostly been appropriate and within suggested guidelines, is indicted by most hospitals admitting < 20% of patients to their emergency medicine governed observation unit and most subsequently admitting < 20% of these to an in-patient ward. Average lengths of stay are less than 12 hours and caseloads commonly include toxicology, low-risk chest pain and abdominal pain although the gamut of minor medical and surgical conditions are seen.

Increasingly outpatient observation services are used to treat patients arriving in emergency departments when the patient is not well enough to be discharged home, the diagnosis has not been substantiated, or therapeutic management has not been completed. Using electronic health record (HER) dashboards and reports assists managing observation patients whether cohorted in specific observation units or scattered through the hospital. Specific observation and admission criteria templates or severity illness indices compliment clinician medical decision making to continue observation, discharge patients home, or transition to admission.

Although the principles of pediatric observation medicine are the same as for adults; e.g. more efficient, safer, cost-effective care with decreased length of stay and equivalent or better patient outcomes; there are differences between pediatric and adult observation unit (OU) patients. The diagnoses are somewhat different with asthma, dehydration, gastroenteritis among the top pediatric diagnoses. Pediatric patients tend to need less cardiac monitoring, fewer medications and fewer laboratory and radiologic studies than adults and have a shorter length of stay. Respiratory illnesses, infections and dehydration/gastroenteritis are the predominant pediatric presenting complaints versus cardiac complaints for adults.

There are many hazards of hospitalization of the older and/or frail adult. Observation units (OUs) are a way of delivering high quality care and an appropriate level of care for older adults, while avoiding a long inpatient hospitalization. Successful intervention in a selected group of elderly patients placed in the geriatric OU from the ED can be achieved with the help of a multidisciplinary team approach.

Of the hyperemesis gravidarum patients who are not ready to be discharged from the emergency department, but are hemodynamically stable, the majority can be successfully managed in the observation unit (OU) with IV fluids and antiemetics. The OU provides an opportunity to inform patients about non-pharmacologic for the nausea/vomiting of pregnancy, including dietary and lifestyle changes.

Pediatric medicine is inherently seasonal, with influenza, respiratory syncytial virus, and other viruses peaking in the winter; this may result in an observation unit (OU) that is full at certain times of the year, while near-empty at others. In order to offset this problem, many pediatric OUs have become hybridized. A hybrid unit is one that serves other functions in addition to the primary role of caring for the typical observation patients. Set standards (including admission criteria, documentation, discharge criteria, length of stay, chain of command and proper staffing) and compliance with these standards is necessary for a pediatric OU to function optimally.

The proportion of the US population over age 65 years has been increasing and is expected to continue to increase. Geriatric patients account for about 20% of emergency department (ED) visits and about 30% of observation unit (OU) patients. A geriatric-focused OU is well suited to serve the needs of the elderly patient. Commonly utilized services include geriatrics, physical therapy, occupational therapy, speech therapy, pharmacists, case managers, and other specialized consultants which may otherwise be difficult to access after-hours or in the ED. Arranging for a comprehensive assessment during a short observation stay avoids an unnecessary and potentially dangerous hospitalization (which exposes vulnerable patients to an increased risk of nosocomial infections, pressure ulcers, deconditioning, deep vein thrombosis, etc.) while still allowing for a period of hospital-based care and observation.

Patients appropriate for the observation unit (OU) include those who are not ready to be discharged home from the emergency department but are not in shock, hemodynamically unstable or will presumptively require a prolonged inpatient stay. Patients who need fluid and/or blood product administration with further evaluation of the cause of the vaginal bleeding are ideal candidates for the OU. A pelvic ultrasound can be performed while the patient is in the OU. If medical management of the bleeding is indicated, then medications can be started in the OU. If a gynecology consult is warranted, it can be done while the patient is in the OU and follow-up arranged.

After completing a fellowship in observation medicine with Dr. Graff in Connecticut, USA, Dr. Mahadevan, started the first observation unit (OU) at National University Hospital in Singapore in 2004. After two additional Singapore physicians completed a fellowship with Dr. Mace in Cleveland, Ohio, USA in 2006-2007, additional OUs were started. Currently, there are seven OUs in Singapore. In 2016, the OU became a “hybrid” unit with the admission of pediatric patients above 6 years of age. During the COVID-19 pandemic in early 2020, the OU was converted into a pandemic isolation ward for suspected COVID + patients in order to increase ED capacity. For reimbursement there needed to be the approval from the government that observation patients could use their medical savings called Medisave). Various protocols have been developed including a protocol on the management of primary spontaneous pneumothorax.. One merit of observation medicine has been a reduction in overall length of stay in the hospital, thus freeing up more inpatient beds for the needy and sicker patients.

Placement in observation is indicated when adequate pain control cannot be achieved, for intractable nausea and vomiting, for dehydrated patients and those with mild acute kidney injury. Medical management consists of supportive measures: pain control, antiemetics, and IV fluids. Medications to promote stone passage may be considered. Follow-up should be arranged with urology, Patients should be given information on prevention, including diet, medications that may predispose to stone formation.

United Kingdom emergency departments (EDs) are subject to complex national performance targets and the recent development of Acute Medicine as a subspeciality branch of general medicine that deals solely with the first 12-72 hours of care of the medically unwell patient. The ‘four-hour rule’, introduced in 2003/4, mandated that 98% of patients presenting to an ED must be seen, treated and then admitted or discharged in under four hours. As a result, many EDs have ED-led observation units (OUs). Given that many UK EDs remain relatively understaffed, OUs tend to be small and take very well-defined low-risk patients. Although the St. Thomas Hospital OU offered a high standard of care, its smooth functioning was often challenged by the demands of the four-hour target, with the OU seen as an option to avoid patients ‘breaching’ their ED length of stay target. In 2012, the model of care was changed, with a focus on goal directed outcomes, for both admission and discharge. Eight beds within the new emergency medical unit (EMU) are now dedicated to goal-directed therapy, with the remainder for rapid goal-directed discharge.