triage table

The triage table

The triage table contains information about the patient when they were first triaged in the emergency department. Patients are assessed at triage by a single care provider and asked a series of questions to assess their current health status. Their vital signs are measured and a level of acuity is assigned. Based on the level of acuity, the patient either waits in the waiting room for later attention, or is prioritized for immediate care.

All fields in triage were originally free-text. For deidentification purposes, the vital sign and pain fields were converted into a numeric value. As a result, a small number of NULL values were introduced for text entries.

Table source: Emergency department information system.

Table purpose: Store information collected on triage to the emergency department.

Number of rows: 425,087

Links to:

• edstays on stay_id

Important considerations

There is no time associated with triage observations. The closest approximation to triage time is the intime of the patient from the edstays table.

The numeric entries in this table were originally stored as free-text. As a result, the columns required deidentification. Free-text entries which could not be converted trivially were removed. Normally, the application of deidentification in MIMIC-IV is indicated using three underscores (___) to make it clear to users that we have modified the data. However, due to the data type restriction, we were unable to do this in this case. As a result, missing data in the numeric columns indicates either deidentified data or no data recorded. However, this is usually rare. Below is a table demonstrating how often data were removed for deidentification purposes:

Column	Number of NULL values inserted for deidentification	Number of rows missing data in v2.1
temperature	680	23415
heartrate	292	17090
resprate	223	20353
o2sat	414	20596
sbp	238	18291
dbp	214	19091
acuity	0	6987

From the above, we can see that of the 23415 rows missing a temperature value, only 680 had a free-text value which was deleted during deidentification (~3%).

Table columns

Name	Postgres data type
subject_id	INTEGER NOT NULL
stay_id	INTEGER NOT NULL
temperature	NUMERIC(10, 4)
heartrate	NUMERIC(10, 4)
resprate	NUMERIC(10, 4)
o2sat	NUMERIC(10, 4)
sbp	NUMERIC(10, 4)
dbp	NUMERIC(10, 4)
pain	TEXT
acuity	NUMERIC(10, 4)
chiefcomplaint	VARCHAR(255)

subject_id

subject_id is a unique identifier which specifies an individual patient. Any rows associated with a single subject_id pertain to the same individual.

stay_id

An identifier which uniquely identifies a single emergency department stay for a single patient.

temperature

The patient’s temperature in degrees Farenheit. Some temperatures may be incorrectly documented as Celsius.

heartrate

The patient’s heart rate in beats per minute.

resprate

The patient’s respiratory rate in breaths per minute.

o2sat

The patient’s peripheral oxygen saturation as a percentage.

sbp, dbp

The patient’s systolic and diastolic blood pressure, respectively, measured in millimitres of mercury (mmHg).

pain

The level of pain self-reported by the patient, on a scale of 0-10.

acuity

An order of priority based upon acuity utilizing the Emergency Severity Index (ESI) Five Level triage system. This priority is assigned by a registered nurse. Level 1 is the highest priority, while level 5 is the lowest priority. The levels are:

• 1
  • When Level 1 condition or patient meets ED Trigger Criteria, the triage process stops, the patient is taken directly to a room and immediate physician intervention requested.
  • Patient conditions which trigger level 1 include being unresponsive, intubated, apneic, pulseless, requiring a medication/intervention to alter ESI level e.g. narcan/adenosine/cardioversion, trauma, stroke, stemi
• 2
  • When a Level 2 condition is identified, the triage nurse notifies the resource nurse and appropriate placement will be determined.
  • Patient conditions which trigger level 2 include high risk situations, new onset confusion, suicidal/homicidal ideation, lethargy, seizures or disorientation, possible ectopic pregnancy, an immunocompromised patient with a fever, severe pain/distress, or vital sign instability
• 3
  • Includes patients requiring two or more resources (labs, EKG, x-rays, IV fluids, etc) with stable vital signs
• 4
  • Patients requiring one resource only (labs, EKG, etc)
• 5
  • Patients not requiring any resources

chiefcomplaint

A deidentified free-text description of the patient’s chief complaint.