Hospital records clock¶

The clocks of the anaesthesia record and the laboratory system, and the rounding of what was entered.

Stub

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


Type	software
Nominal	Clinical and laboratory systems
Kept by	Clinical records

Description¶

The clocks of the anaesthesia record and the laboratory system, and the rounding of what was entered. Not observable in the release except through events seen in the signals. What its stamps mark is known better than its offset: anaesthesia start comes a median 14 minutes before device-marked induction (Post-induction hypotension, from the charted start and from the devices), entries on 5-minute marks are rounded up, clearly so at anaesthesia end (Anaesthesia record times are rounded up; the value models disagree for the starts and for operation end), and a blood gas's lab time comes a median 7.2 minutes after the draw (Blood gas timestamp after the draw).

Route to UTC¶

The route the atlas trusts most (2 links; its weakest link is assumed apart from the link to UTC that every clock shares):

Hospital records clock

link assumed Hospital records clock against the recorder PC

Recorder PC clock

link assumed Recorder PC against UTC: drift 0.1–10 ppm (assumed); corrected every 8–24 h (assumed)

UTC

Where every route ends.

Plan. Not observable: the clinical and lab times share the case start with the recorder, so any offset cancels, and it is confounded with documentation lag. Signal-side events (drug effects, arterial draws) bound it to minutes. To measure it needs a time from outside the release.

Links to other clocks¶

Link	Clock	Against	Modes	Rate	Corrected every	Status
Hospital records clock against the recorder PC	Hospital records clock	Recorder PC clock	all	—	—	assumed

Variables stamped by this clock¶

Albumin, Alanine transferase, Ammonia, Anesthesia end time, Anesthesia start time, Activated partial thromboplastin time, Asparate transferase, Base excess, Blood urea nitrogen, Case end, Creatinine clearance, Chloride, Creatinine, C-reactive protein, Erythrocyte sedimentation rate, Fibrinogen, Glomerular filtration rate, Glucose, Hemoglobin, Bicarbonate, Hematocrit, Ionized Calcium, Potassium, Lab timestamp (seconds from casestart), Lactate, Sodium, Operation end time, Operation start time, Probably phosphorus (unconfirmed): not in lab_parameters.csv, Partial pressure of CO₂, pH, Platelet count, Partial pressure of O₂, Prothrombin time (%), Prothrombin time (INR), Prothrombin time (sec), Arterial oxygen saturation, Total bilirubin, Total protein, White blood cell count, Admission and discharge, Anaesthesia record events, Blood gas result time, Central lab result time

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.
Op end was filled in from the recording end in 537 cases	established	In 537 cases (8.4%) the op end is exactly 10 minutes before the end of the recording, so it was filled in rather than charted. These cases are concentrated in thoracic surgery and under sedation or spinal anaesthesia.
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 lab time is neither the draw nor the result	established	VitalDB's lab timestamp marks the specimen (logged at the lab, or entered from a theatre analyser): minutes after the draw and before the result, whose time is not recorded.
Some ICU stays are longer than the postoperative stay	likely	In 37 cases the ICU day count reaches or exceeds the days from surgery to discharge, though the release describes it as the postoperative ICU stay. Most are emergencies with long stays before surgery, so the count probably includes ICU days before the operation.

Studies¶

Study	Date	Status	Summary
What the lab timestamp marks	2026-10-13	current	VitalDB's lab time is a per-specimen timestamp: not the draw, and not the result. Blood gases are stamped 3–12 minutes after the draw, central-lab panels about 8–24 minutes after it, and the result follows a turnaround the release does not record.
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.

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