Variables¶

Every recorded quantity: a waveform, a numeric, an event, a clinical field, a lab result. Each is described on two axes, time and value, each with its accuracy and its resolution.

Section	Groups
Monitoring	Waveforms (7), Numerics (13)
Clinical record	Times and durations (14), Patient (7), Operation and anaesthesia (7), Preoperative history (4), Airway and lines (11), Fluids and blood (6), Drugs (9), Outcome (3)
Laboratory	Preoperative labs (18), Blood gas (7), Electrolytes and glucose (6), Haematology (5), Coagulation (5), Chemistry (11), Result times (3)

Monitoring¶

Waveforms¶

Variable	Time	Value	Summary
Airway pressure (Primus)	timing	—	Airway pressure from the Primus anaesthesia machine at 62.5 Hz.
Arterial pressure (SNUADC)	chain	—	Invasive arterial pressure, sampled by SNUADC at 500 Hz from the monitor's analogue output.
BIS EEG	chain	—	The raw EEG from the BIS monitor at 128 Hz.
Capnogram (Primus)	timing	—	Sidestream CO₂ from the Primus at 62.5 Hz; the sampling line adds at least 1 s.
CardioQ pressure and flow	timing	—	Arterial pressure and aortic flow waveforms from the CardioQ oesophageal Doppler monitor.
ECG lead II (SNUADC)	chain	—	Lead II of the ECG, sampled by SNUADC at 500 Hz from the monitor's analogue output.
Plethysmogram (SNUADC)	chain	—	The pulse oximeter's plethysmogram, sampled by SNUADC at 500 Hz. It reaches SNUADC through the oximeter's own 30 Hz frame clock and a hardware delay of about 0.4 s.

Numerics¶

Variable	Time	Value	Summary
BIS index	timing	—	The BIS depth-of-anaesthesia index, computed from a window of EEG.
EV1000 mean arterial pressure	timing	—	Mean arterial pressure from the EV1000 platform, updated every 20 s.
FMS rapid infuser	timing	—	Rapid infuser flow and volume.
Infusion pump rates and volumes	timing	—	Drug infusion rates and volumes from the pumps.
Invos regional oxygen saturation	timing	—	Cerebral oximetry; no signal shared with the reference.
Non-invasive blood pressure	timing	—	Cuff blood pressure, recorded after each cuff cycle.
Primus ETCO₂, PIP and RR	timing	—	End-tidal CO₂, peak pressure and respiratory rate from the Primus, polled about every 7 s.
Solar8000 ART and CVP numerics	timing	—	Arterial and central venous pressure values from the Solar8000 monitor.
Solar8000 heart rate	chain	—	Heart rate from the Solar8000, in one of two delay groups per case.
Solar8000 pulse rate (PLETH_HR)	timing	—	Pulse rate from the oximeter, over about 12 beats.
SpO₂	timing	—	Oxygen saturation from the pulse oximeter.
Vigilance continuous cardiac output	timing	—	Continuous cardiac output and averaged HR.
Vigileo SV, CO and SVV	timing	—	Stroke volume, cardiac output and stroke volume variation.

Clinical record¶

Times and durations¶

Variable	Time	Value	Summary
Admission and discharge	timing	—	Hospital admission and discharge, in days.
Admission time from casestart	—	resolution	Admission time from casestart (clinical table).
Anaesthesia duration	—	resolution	Anaesthesia duration (derived table).
Anaesthesia record events	chain	—	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).
Anaesthesia start to incision	—	resolution	Anaesthesia start to incision (derived table).
Anesthesia end time	stamped	model	Anesthesia end time; from casestart (clinical table).
Anesthesia start time	stamped	model	Anesthesia start time; from casestart (clinical table).
Case end	timing	resolution	The end of the recording in the clinical table.
Discharge time from casestart	—	resolution	Discharge time from casestart (clinical table).
Operation duration	—	resolution	Operation duration (derived table).
Operation end time	stamped	model	Operation end time; from casestart (clinical table).
Operation end to anaesthesia end	—	resolution	Operation end to anaesthesia end (derived table).
Operation start time	stamped	model	Operation start time; from casestart (clinical table).
Recording Start Time	stamped	resolution	Recording Start Time; Set to 0 for anonymization (clinical table).

Patient¶

Variable	Time	Value	Summary
Age	—	resolution	Age (clinical table).
ASA Physical status classification	—	—	ASA Physical status classification (clinical table).
Body mass index	—	model	Body mass index (clinical table).
Emergency operation	—	—	Emergency operation (clinical table).
Height	—	model	Height (clinical table).
Sex	—	—	Sex (clinical table).
Weight	—	model	Weight (clinical table).

Operation and anaesthesia¶

Variable	Time	Value	Summary
Anesthesia type	—	—	Anesthesia type (clinical table).
Diagnosis	—	—	Diagnosis (clinical table).
Operation name	—	—	Operation name (clinical table).
Surgery type	—	—	Surgery type (clinical table).
Surgical approach	—	—	Surgical approach (clinical table).
Surgical department	—	—	Surgical department (clinical table).
Surgical position	—	—	Surgical position (clinical table).

Preoperative history¶

Variable	Time	Value	Summary
Preoperative diabetes	—	—	Preoperative diabetes (clinical table).
Preoperative ECG	—	—	Preoperative ECG (clinical table).
Preoperative hypertension	—	—	Preoperative hypertension (clinical table).
Preoperative pulmonary function	—	—	Preoperative pulmonary function (clinical table).

Airway and lines¶

Variable	Time	Value	Summary
Airway route	—	—	Airway route (clinical table).
Cormack's grade	—	—	Cormack's grade (clinical table).
Double lumen tube size	—	—	Double lumen tube size (clinical table).
Endotracheal tube size	—	—	Endotracheal tube size (clinical table).
LMA size	—	—	LMA size (clinical table).
Site of arterial line (1)	—	—	Site of arterial line (1) (clinical table).
Site of arterial line (2)	—	—	Site of arterial line (2) (clinical table).
Site of central line (1)	—	—	Site of central line (1) (clinical table).
Site of central line (2)	—	—	Site of central line (2) (clinical table).
Site of IV line (1)	—	—	Site of IV line (1) (clinical table).
Site of IV line (2)	—	—	Site of IV line (2) (clinical table).

Fluids and blood¶

Variable	Time	Value	Summary
Estimated blood loss	—	model	Estimated blood loss (clinical table).
Intraoperative colloid	—	resolution	Intraoperative colloid (clinical table).
Intraoperative crystalloid	—	model	Intraoperative crystalloid (clinical table).
Intraoperative FFP transfusion	—	resolution	Intraoperative FFP transfusion (clinical table).
Intraoperative RBC transfusion	—	resolution	Intraoperative RBC transfusion (clinical table).
Intraoperative urine output	—	model	Intraoperative urine output (clinical table).

Drugs¶

Variable	Time	Value	Summary
Calcium chloride	—	resolution	Calcium chloride (clinical table).
Ephedrine	—	resolution	Ephedrine (clinical table).
Epinephrine	—	resolution	Epinephrine (clinical table).
Fentanyl	—	resolution	Fentanyl (clinical table).
Midazolam	—	resolution	Midazolam (clinical table).
Phenylephrine	—	resolution	Phenylephrine (clinical table).
Propofol bolus	—	model	Propofol bolus (clinical table).
Rocuronium	—	resolution	Rocuronium (clinical table).
Vecuronium	—	resolution	Vecuronium (clinical table).

Outcome¶

Variable	Time	Value	Summary
ICU days	—	resolution	ICU days (clinical table).
In-hospital Mortality	—	—	In-hospital Mortality (clinical table).
Length of hospital stay (dis - adm)	—	resolution	Length of hospital stay (dis - adm) (derived table).

Laboratory¶

Preoperative labs¶

Variable	Time	Value	Summary
Preoperative albumin	—	resolution	Preoperative albumin (clinical table).
Preoperative aPTT	—	resolution	Preoperative aPTT (clinical table).
Preoperative base excess	—	resolution	Preoperative base excess (clinical table).
Preoperative blood urea nitrogen	—	resolution	Preoperative blood urea nitrogen (clinical table).
Preoperative creatinine	—	resolution	Preoperative creatinine (clinical table).
Preoperative glucose	—	resolution	Preoperative glucose (clinical table).
Preoperative GOT	—	resolution	Preoperative GOT (clinical table).
Preoperative GPT	—	resolution	Preoperative GPT (clinical table).
Preoperative HCO3-	—	resolution	Preoperative HCO3- (clinical table).
Preoperative hemoglobin	—	resolution	Preoperative hemoglobin (clinical table).
Preoperative K	—	resolution	Preoperative K (clinical table).
Preoperative Na	—	resolution	Preoperative Na (clinical table).
Preoperative PaCO₂	—	resolution	Preoperative PaCO₂ (clinical table).
Preoperative PaO₂	—	resolution	Preoperative PaO₂ (clinical table).
Preoperative pH	—	resolution	Preoperative pH (clinical table).
Preoperative platelet count	—	resolution	Preoperative platelet count (clinical table).
Preoperative PT	—	resolution	Preoperative PT (clinical table).
Preoperative SpO₂	—	resolution	Preoperative SpO₂ (clinical table).

Blood gas¶

Variable	Time	Value	Summary
Arterial oxygen saturation	stamped	resolution	Arterial oxygen saturation (lab table).
Base excess	stamped	resolution	Base excess (lab table).
Bicarbonate	stamped	resolution	Bicarbonate (lab table).
Lactate	stamped	resolution	Lactate (lab table).
Partial pressure of CO₂	stamped	resolution	partial pressure of CO₂ (lab table).
Partial pressure of O₂	stamped	resolution	partial pressure of O₂ (lab table).
pH	stamped	resolution	pH (lab table).

Electrolytes and glucose¶

Variable	Time	Value	Summary
Chloride	stamped	resolution	Chloride (lab table).
Glucose	stamped	resolution	Glucose (lab table).
Ionized Calcium	stamped	resolution	ionized Calcium (lab table).
Potassium	stamped	resolution	Potassium (lab table).
Probably phosphorus (unconfirmed): not in lab_parameters.csv	stamped	resolution	Probably phosphorus (unconfirmed): not in lab_parameters.csv; median 3.2, IQR 2.7-3.8, 5th-95th percentile 1.9-5.0, consistent with inorganic phosphorus in mg/dL. Name kept as released. (lab table).
Sodium	stamped	resolution	Sodium (lab table).

Haematology¶

Variable	Time	Value	Summary
Erythrocyte sedimentation rate	stamped	resolution	Erythrocyte sedimentation rate (lab table).
Hematocrit	stamped	resolution	Hematocrit (lab table).
Hemoglobin	stamped	resolution	Hemoglobin (lab table).
Platelet count	stamped	resolution	Platelet count (lab table).
White blood cell count	stamped	resolution	White blood cell count (lab table).

Coagulation¶

Variable	Time	Value	Summary
Activated partial thromboplastin time	stamped	resolution	Activated partial thromboplastin time (lab table).
Fibrinogen	stamped	resolution	Fibrinogen (lab table).
Prothrombin time (%)	stamped	resolution	Prothrombin time (%) (lab table).
Prothrombin time (INR)	stamped	resolution	Prothrombin time (INR) (lab table).
Prothrombin time (sec)	stamped	resolution	Prothrombin time (sec) (lab table).

Chemistry¶

Variable	Time	Value	Summary
Alanine transferase	stamped	resolution	Alanine transferase (lab table).
Albumin	stamped	resolution	Albumin (lab table).
Ammonia	stamped	resolution	Ammonia (lab table).
Asparate transferase	stamped	resolution	Asparate transferase (lab table).
Blood urea nitrogen	stamped	resolution	Blood urea nitrogen (lab table).
C-reactive protein	stamped	resolution	C-reactive protein (lab table).
Creatinine	stamped	resolution	Creatinine (lab table).
Creatinine clearance	stamped	resolution	Creatinine clearance (lab table).
Glomerular filtration rate	stamped	resolution	Glomerular filtration rate (lab table).
Total bilirubin	stamped	resolution	Total bilirubin (lab table).
Total protein	stamped	resolution	Total protein (lab table).

Result times¶

Variable	Time	Value	Summary
Blood gas result time	chain	—	Time stamp of a blood gas result in the lab table.
Central lab result time	chain	—	Time stamp of a central laboratory result in the lab table.
Lab timestamp (seconds from casestart)	stamped	resolution	Lab timestamp (seconds from casestart) (lab table).