​A 'third pathway' in emergency care: the emergency observation ward (EOW). Through specially curated and protocolised care, the EOW can prevent unnecessary inpatient admissions and costs to the patient. The Department of Emergency Medicine (DEM), Singapore General Hospital shares more. 


  • The emergency observation ward (EOW) is a short stay in the ED for a selected group of patients who may benefit from specially curated, protocolised care.

  • The EOW could prevent unnecessary inpatient admissions and costs to the patient.

  • A multidisciplinary approach is increasingly being utilised to bring care to the forefront.

  • A variety of medical conditions are suitable for EOW stay, which is not limited to the below-mentioned conditions.



Since emergency medicine became recognised as a specialty in medicine, there have been developments in the management of specific groups of patients in the emergency department (ED) who would benefit from a ‘third pathway’: the emergency observation ward (EOW).1

The traditional pathways of managing patients in the ED have been dichotomous – either discharge or admission to an inpatient setting. These binary management options are not always the most ideal for the diverse conditions that patients present to the ED with, as they may lead to unnecessary costs, increased duration of hospital stay and other potential complications such as nosocomial infections.


There is a select group of patients and conditions that requires more time in the ED as they cannot be safely discharged within the time frame of approximately 1 to 5 hours (the expected average duration of stay in the ED), or because the main problem they have presented with has not resolved.

These patients have a specific endpoint target to meet, and have to be carefully selected to benefit from their stay in the observation ward.


Such conditions include:

  • Pain syndromes (e.g., renal colic, undifferentiated abdominal pain, mechanical back pain, gout)
  • First-onset seizure
  • Allergies
  • Gastroenteritis
  • Minor trauma
  • Pneumothorax
  • Cellulitis


Types of EOWs

There are four distinct types of observation wards2 or units, as described in Table 1 below.
Table 1 Types of observation wards/units

Observation ward/unit type
​Corresponding approach to patient care
IProtocol-based care

Based in a dedicated observation ward located in the ED

​IIDiscretionary care

Based in a dedicated observation ward typically located in the ED

​IIIProtocol-based care

Any location in the hospital

​IVDiscretionary care

Any location in the hospital 


The Singapore General Hospital (SGH) Department of Emergency Medicine (DEM) adheres only to type I, which is the short-stay protocolised care approach


Patients have to meet the well-defined inclusion criteria to be admitted to the observation ward, and the provider needs to ensure that they do not fall into any of the exclusion criteria. This is important as there could be bad outcomes when a patient is observed in the ED rather than being admitted to an inpatient discipline for definitive workup or management.

For example, in a patient who is being observed for non-specific abdominal pain or gastroenteritis-like symptoms, the presence of unstable hemodynamic parameters such as hypotension could suggest early septic shock and raise suspicion for intra-abdominal infection, such as hepatobiliary sepsis or colitis.

They should be admitted to the surgical discipline and undergo further advanced imaging such as CT scans and even early access to the operating theatre. Hence, careful patient selection is paramount.


In 2004, protocol-based EOW care was launched in SGH DEM. From October 2015 to January 2020 (at which point the COVID-19 pandemic struck), there was an average of 551 admissions per month to the EOW.

The majority of these cases were from the now-defunct chest pain observation protocol, which was discontinued after evolving evidence showed that normal serial two-hour high-sensitivity troponin levels correlated with a major adverse cardiovascular events (MACE) incidence of less than 2%, and patients could be safely discharged.3

EOW protocols, criteria and interventions

As of August 2022, SGH has a total of 23 observation ward protocols, 18 of them being currently operational and the rest undergoing revision with a view to reopen in phases. During the COVID-19 pandemic, the EOW was not functioning for approximately a year due to changes in the workflow of the department and safety measures to segregate infectious patients.

Our protocols include renal colic, pneumothorax, poisoning, smoke inhalation, hyperthyroidism, atrial fibrillation (AF) and bites and stings. A summary of some of these protocols, their entry criteria and treatment interventions are provided in Table 2.

Table 2 Summary of selected EOW protocols at SGH



ProtocolPatient selectionInterventions
GastroenteritisMild-to-moderate dehydration without surgical abdomen or bloody diarrhoea
  • Oral/IV hydration
  • Rehydration salts
CellulitisFailed oral antibiotics but not involving face, neck, perineum and not in overt sepsis
  • IV antibiotics as per SGH antimicrobial guidelines
  • Demarcate the region and review for improvement
Hyperglycaemia Not in diabetic ketoacidosis (DKA) or hyperosmolar hyperglycaemic nonketonic syndrome (HHNK) / hyperosmolar hyperglycaemic syndrome (HHS)
  • Sliding scale Actrapid insulin
  • Oral hypoglycaemic agents as indicated
  • Diabetes mellitus counselling
Minor injuriesMusculoskeletal pain after minor trauma not resolving with initial analgesia
  • Analgesia as per pain ladder
  • Physiotherapy if required
Hypertension Hypertensive urgency without overt end organ damage or illicit drug use
  • Initiate antihypertensives if newly diagnosed or titrate as needed
Atrial fibrillation (AF)
  • Onset of AF >48 hours
  • Hemodynamically stable
  • Absence of both sepsis and hyperthyroidism
  • Continuous cardiac monitoring
  • Starting anticoagulation in the ED
HyperthyroidismHemodynamically stable, clinically not in thyroid storm
  • Start antithyroid medications such as carbimazole plus propranolol
  • Check for AF; follow up with endocrine +/- cardiology if AF is detected


The EOW is an example of how patient care can be transformed with multidisciplinary efforts. The patient journey is shortened, and essential services are brought to the patient's bedside with close follow-up plans on discharge. This has many benefits, including being cost-effective for patients and preventing unnecessary waiting time for inpatient beds and services.

In 2024, SGH will be moving to its new emergency medicine building observation ward with up to 38 beds, which will be opened in phases. With these continued collaborative efforts, it hopes to further enhance its observation medicine practice to improve patient satisfaction and promote positive clinical outcomes.



  1. Observation medicine: A Healthcare's tincture of time. Louis G Graff.

  2. The "ABCs" of Observation Medicine. Michael A. Ross

  3. Ziwei Lin, Swee Han Lim, et al. Comparing conventional and high sensitivity troponin T measurements in identifying adverse cardiac events in patients admitted to an Asian emergency department chest pain observation unit. IJC Heart & Vasculature, Volume 34, 2021.https://doi.org/10.1016/j.ijcha.2021.100758.