procedureevents

The procedureevents table

Table source: MetaVision ICU database.

Table purpose: Contains procedures for patients

Number of rows: 696,092

Links to:

• patients on subject_id
• admissions on hadm_id
• icustays on stay_id
• d_items on itemid

Important considerations

This table is not a required documentation field during routine care. As a result, existence of procedures here indicates their presence, but absence does not indicate the procedure was not conducted. The consistency of documentation varies by the type of procedure. For example, invasive ventilation tends to be documented, whereas non-invasive documentation is less consistently documented.

Table columns

Detailed Description

subject_id, hadm_id, stay_id

Identifiers which specify the patient: subject_id is unique to a patient, hadm_id is unique to a patient hospital stay and stay_id is unique to a patient ICU stay.

caregiver_id

caregiver_id uniquely identifies a single caregiver who documented data in the ICU information system.

starttime, endtime

starttime and endtime record the start and end time of an event.

storetime

storetime specifies the time when the event was recorded in the system.

itemid

Identifier for a single measurement type in the database. Each row associated with one itemid (e.g. 212) corresponds to a type of measurement (e.g. heart rate). The d_items table may be joined on this field. For any itemid appearing in the procedureevents table, d_items linksto column will have the value ‘procedureevents’.

value

In the procedureevents table, this identifies the duration of the procedure (if applicable). For example, if querying for itemid 225794 (“Non-invasive Ventilation”), then the value column indicates the duration of ventilation therapy.

valueuom

The unit of measurement for the value. Most frequently “None” (no value recorded); otherwise one of “day”, “hour”, or “min”. A query for itemiid 225794 (“Non-invasive Ventilation”) returning a value of 461 and valueuom of ‘min’ would correspond to non-invasive ventilation provided for 461 minutes; this value is expected to match the difference between the starttime and endtime fields for the record. A procedure with valueuom equal to “None” corresponds to a procedure which is instantaneous (e.g. intubation, patient transfer) or whose duration is not relevant (e.g. imaging procedures). For these records, there will be a difference of one second between starttime and endtime values.

location , locationcategory

location and locationcategory provide information about where on the patient’s body the procedure is taking place. For example, the location might be ‘Left Upper Arm’ and the locationcategory might be ‘Invasive Venous’.

orderid, linkorderid

These columns link procedures to specific physician orders. Unlike in the mimic_icu.inputevents table, most procedures in procedureevents are ordered independently.

There are a limited number of records for which the same procedure was performed again at a later date under the same original order. When a procedure was repeated under the same original order, the linkorderid field of the record for the later procedure will be set to the orderid field of the earlier record. In all other cases, orderid = linkorderid.

ordercategoryname, ordercategorydescription

These columns provide higher level information about the medication/solution order. Categories represent the type of administration.

patientweight

The patient weight in kilograms.

isopenbag

Whether the order was from an open bag.

continueinnextdept

If the order ended on patient transfer, this field indicates if it continued into the next department (e.g. a floor).

statusdescription

statusdescription states the ultimate status of the procedure referred to in the row. The statuses appearing on the procedureevents table are:

• Paused - The current delivery has been paused.
• FinishedRunning - The delivery of the item has finished (most frequently, the bag containing the compound is empty).
• Stopped - The delivery of the item been terminated by the caregiver.

Nearly all procedures recorded in procedureevents have a status of FinishedRunning.

originalamount, originalrate

These fields are present in the table and never null, but have no clear meaning. In particular, “originalrate” is either 0 or 1 for all records.