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Observation Medicine - Clinical Decision Unit

Traditionally, patients who require services beyond the first hours in the emergency department (ED) have been admitted to the acute care hospital. Economic pressures for efficiency in health care have led to the need for new strategies for the care of patients with acute chest pain and similar difficult to rapidly diagnose ED presentations. Thus, observation units are increasingly becoming an important component of the modern ED. Observation is by definition the use of appropriate monitoring, diagnostic testing, therapy, and assessment of patient symptoms, signs, laboratory tests, and response to therapy for the purpose of determining whether a patient will require further treatment as an inpatient or can be discharged form the hospital setting.

The goal of the observation unit is to lower health care costs by creating incentives for efficient, effective health care. In general, hospitals try to limit costs by preventing complications and prolonged hospitalizations, since the hospital is paid a lump sum based on the patient's diagnosis (DRG) irrespective of the length of stay. To putatively avoid abuse of the system (admitting of patients who are not "sick"), the hospital is not reimbursed for an admitted Medicare patient who fails to meet intensity of service and severity of illness criteria (Medicare Admission Criteria). With the observation status bed, the patient is billed on an outpatient basis, while those requiring over 24 hours of observation must meet inpatient DRG criteria for reimbursement and must be billed as inpatients.

The duration of observation status is expected to be from 8-24 hours. Prior studies indicate that observation unit care can improve outcomes and improve cost effectiveness compared to routine care. Chest pain observation units have been developed in many hospitals, and are widely considered to have the potential to provide rapid and safe evaluations for low-risk patients with acute chest pain. Studies have shown that use of a chest pain observation unit reduces the proportion of patients admitted by 17%, and the proportion discharged with acute coronary syndrome from 14% to 6%. Care in the chest pain observation unit has been associated with improved health utility during follow up, 0.0137 quality adjusted life years gained. A conservative estimate from these studies is that more than $1000 in health care charges is saved per patient.

The Clinical Decision Unit or CDU is the observation unit in the emergency department. It is designed to provide appropriate physician and nurse staffing and diagnostic/treatment capabilities to allow observation for the presenting clinical complaint in an efficient, safe, effective and comfortable environment.

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The Philosophy of CDU care

  • To provide an area to care for any patient who has not been admitted but whose condition necessitates a lengthy observation, not to exceed 24 hours.
  • To provide an area for observation for testing when a patient does not meet screening criteria for an acute care setting.
  • Deliver excellence in clinical care by correctly diagnosing heart attack (Myocardial Infarction or MI) or patients and more rapidly diagnosing acute coronary syndromes so that therapy may be implemented expediently. undefined
  • Allow additional time to make difficult disposition decisions and, thus, allow more certainty of diagnosis. To create new research opportunities and increase overall knowledge in implementation of care in the ED.
  • Benefits to patients
  • Observation services are an extension of ED evaluation and stabilization services beyond the traditional two- to three-hour limit. A benefit of this continued patient management is better definition of the patient's problem with reduction in both costs and inappropriate dispositions.
  • Ultimate goal is to improve the quality of medical care to patients through extended evaluation and treatment while reducing inappropriate admissions and health care costs
  • Help minimize patient delays in seeking medical care and delays in the ED itself.
  • Cost saving compared with an in-hospital evaluation to rule-out life threatening disease such as acute MI.
  • Deliver excellence in clinical care by appropriately identifying MI patients and more rapidly diagnosing acute coronary syndromes so that therapy may be implemented expediently.

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CDU admissions are limited to those patients specifically deemed appropriate for short-term evaluation and the therapy (up to 24 hours), and whose care can be better managed in the CDU. For example, chest pain patients to be admitted with a somewhat limited workup needed, i.e. r/o with enzymes and treadmill testing.

At the discretion of the ED attending and resource nurse, at time of high ED volume, criteria may be expanded to include those patients admitted and awaiting inpatient bed placement.

The severity of illness must not preclude the expectation that the patient will be discharged within established time limits thus patients must have an 85% likelihood of discharge within a 24 hour observation period.
Patients should not be admitted to an observation bed if the physician can not identify a goal of patient care that can reasonably be expected to be met within a time limit.

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Specific Admitting Diagnoses

  • Chest pain or similar symptoms suggestive but not diagnostic of an acute MI
  • Hyperosmolar nonketotic state or diabetic ketoacidosis (uncomplicated)
  • Acute asthmatic attack
  • Acute exacerbation of chronic lung disease
  • Uncontrolled hypertension
  • Drug reactions
  • Allergic reactions
  • Dehydration requiring intravenous repletion (e.g., secondary to vomiting, diarrhea, anorexia, etc.)
  • Short term therapy such as seizure disorder requiring anticonvulsant loading, sickle cell pain crisis, transfusion of blood,
  • Psychosocial need, i.e. alcohol intoxication, depression, psychosis, social disposition problems
  • Abdominal pain suggesting an acute abdominal process, but not readily defined
  • Gastrointestinal bleeding of uncertain nature of significance, etc.
  • Infections, requiring short-term parenteral antibiotic therapy (e.g., pneumonia, cellulites, urinary tract infection)

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CDU Volume and Length of Stay

Since its inception in the fall of 2002, the CDU census has steadily risen each year. In 2006, 3576 patients were admitted to the CDU for observation. This represents approximately 7% of all ED visits for that year. Sixteen percent of these patients subsequently were admitted to the hospital - a number very close to our expressed target of 15%. Fewer than 0.1% of the observed patients were ultimately admitted to an intensive care unit.

On average in 2006, 69 patients were admitted per week or approximately 10 patients admitted daily were placed in the CDU for an 8-24 hour observation period. Thus, the 24 hours census was at 125% occupancy. About 50% of these patients were admitted to rule acute cardiac ischemia. Of these, 6% were subsequently diagnosed with an acute coronary syndrome. The remaining 50% of patients were observed in descending order of frequency for cellulitis, dehydration, other infections, drug or allergic reactions, asthma/COPD, psychosocial needs, trauma, or other diverse diagnoses. Cellulitis was the most common CDU diagnosis, which subsequently required hospital admission.

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Patient Satisfaction Goals

  • To reduce hospitalization and health care costs for patients.
  • To provide a more comfortable area for medical care while the patient is in an observation setting.
  • To deliver outstanding patient care with high levels of patient satisfaction. 
  • The CDU repeatedly elicits letters from patients reiterating high levels of satisfaction
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Contact Information

Shumai Grossman, MD
Director, Clinical Decision Unit
Department of Emergency Medicine
West Campus Clinical Center
190 Pilgrim Road
Boston, MA 02215

Locating a Patient

Call the Emergency Room at 617-754-2450.

Our Emergency Room is located on the WEST CAMPUS of BIDMC at 190 Pilgrim Rd.

Directions to the ER