Anaesthesia record events¶

Anaesthesia and operation start and end times in the clinical table. Anaesthesia start marks the start of anaesthesia care, a median 14 minutes before device-marked induction (Post-induction hypotension, from the charted start and from the devices).

Stub

Imported from the time-source table; the full page is still to be written.


Name in the dataset	`clinical_data times`
Type	event
Device	Clinical records
Stamped by	Hospital records clock

Measurement space¶

Time side (5-minute entries): the true time lies between -900 s and -150 s from the stamp: the delay range plus the interval one value describes.

Time¶

From UTC to the stored time stamp¶

The clock path first (UTC to the clock that stamps or spaces the samples), then the signal's own path to its stored time. Each bar: the time shift or error the step introduces (pale) and what is left after the atlas's correction (solid), on a log scale; dashed when estimated or assumed.

UTC

The reference every chain starts from.

Hospital records clock

sync assumed

The laboratory and anaesthesia record systems keep hospital time (KST). Their offset from UTC and from the recorder PC is not observable in the release, which shifts every case to 2100.

Documentation

processing measured 0 ms – 5 min · parameter, Anaesthesia record times are rounded up

Entered in the anaesthesia record with a lag that is not measured separately; entries on a 5-minute mark were rounded up to it, so the event lies in the 5 minutes before, about 2.5 min earlier on average (clearly so at anaesthesia end; for the other times two studies disagree, see Anaesthesia record times are rounded up).

Stored clinical time

stamping measured 60 s – 5 min

On a 1-minute or 5-minute grid, relative to the case start.

Timing¶

Against the working reference. Delay: from the end of the interval a value describes to its stamp. Interval: how wide that interval is.

Form	Delay	Interval	Clock domain	Status	Evidence
5-minute entries (default)	2.5 min – 10 min	5 min	Clinical and lab records	measured	rounded up: 90-290 s later than minute entries; ceiling kernel best in 11/11 device markers (small margin at anaesthesia start, where the value model prefers the nearest mark; op end floor by its value model)
minute entries	30 s – 5 min	60 s	Clinical and lab records	estimated	minute grid, 5-min entries rounded up; anaesthesia start a median 14 min (p10-p90 6-25) before device induction (2,913 cases); per-entry documentation lag not measured

Combine it with other signals in the synchronisation planner.

Value¶

Its value side is still to be described.

Parameters¶

Parameter	Value	Status	From
EMR 5-minute entries, rounding	(t − 300 s, t]; estimate t − 150 s (SD 87 s); observed shift against minute entries −89 to −293 s	measured	Anaesthesia record times are rounded up

Observations¶

Observation	Status	Summary
Anaesthesia record times on 5-minute marks are rounded up	established	An anaesthesia start or end entered on a 5-minute mark was rounded up to it: the event happened in the 5 minutes before, and on average a little earlier still. Clear for anaesthesia end; for anaesthesia start the margin is small, and the value model (How the anesthesia start time was charted) prefers rounding to the nearest mark.
The EMR clock's offset cannot be separated from documentation lag	established	Both routes between the EMR clock and the recorder run through the case start, so any EMR clock offset cancels. Without a time from outside the release it is confounded with how late entries are made.
The EVENT track repeats the clinical table	established	In 411 random cases the recorder EVENT track's four entries equal the clinical table's case start, operation start, operation end and case end exactly: the release generated them from the table.

Studies¶

Study	Date	Status	Summary
Closing loops in the timing graph	2026-10-13	current	Where two independent routes reach the same clock, the offsets around the loop must sum to zero. Three measured loops close within their noise; the BIS loop closes up to a constant latency; the proposed EMR loop is not a loop at all.
Recovering the time of day	2026-10-12	current	The release shifts every case to start at 2100-01-01 00:00 UTC, removing the date and the time of day. The time of day (Korean local time) can be recovered to the minute from the admission date and the seconds of the EMR times.
Anaesthesia record times are rounded up	2026-10-12	current	Anaesthesia start and end entered on a 5-minute mark sit 90–290 s later, against device markers, than entries typed to the minute. Rounding up to the next 5 minutes fits every one of 11 markers better than rounding to the nearest or down.

Worked examples¶

Example	Side	Status	Summary
Post-induction hypotension, from the charted start and from the devices	time	draft	The charted anaesthesia start comes a median 14 minutes before the patient is induced; measured from it, "hypotension within 20 minutes of induction" is found in 27% of 2,913 patients, against 51% from the devices' induction, and the label changes for a quarter of patients.
Time from a vasopressor bolus to the pressure response	both	planned	How quickly arterial pressure responds to a phenylephrine or ephedrine bolus, with the charted dose times' rounding taken into account. Not feasible in VitalDB, which records bolus totals but no bolus times; kept for a dataset that does.

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