Perfusion Time Calculator for CPB Workflows
Track case intervals with quick start/end time inputs and automatic elapsed-minute calculations.
Time Calculator
Enter 24-hour start/end times to see elapsed minutes and an H:MM readout.
Tap the clock icon to insert the current time.
Record mode keeps manual entry. Live mode adds per-row Start, Stop, Reset tracking.
Previous case data found. Continue previous timers or start a new case?
Live mode is a workflow timer for documentation support. Verify all times against the heart-lung machine, anesthesia record, and institutional charting workflow. Do not enter patient identifiers. Live timer data is stored only in this browser; use New case / Clear all to remove stored case data.
Cardioplegia reminder
Not startedOptional reminder from dose completion. Verify against pump timer, charting record, and local myocardial protection protocol.
Starts from dose completion. Use as an optional workflow reminder; verify against pump timer and institutional practice.
Case summary
Review and copy completed time events. Do not include patient identifiers.
Copy the summary before starting a new case if needed.
Time calculation notes
1. Purpose
This time calculator is designed to quickly estimate elapsed time in minutes and H:MM format between two clock times. It is intended for tasks such as documenting CPB time, cross-clamp time, cardioplegia intervals, ECMO procedure time blocks, or other peri-operative events where only start and end times are known.
2. Input format
Times are entered in 24-hour format as HH:MM.
Valid range: 00:00–23:59.
Examples: 07:15, 13:40, 21:05.
The fields accept four digits; after four digits are typed (e.g., 1345), the value is auto-formatted to 13:45.
Each row is independent and can be labelled (e.g., “CPB on–off”, “Cross-clamp”, “Circulatory arrest”).
3. Core calculation
For each row:
Convert start and end times to total minutes from midnight:
totalMinutes = 60 × HH + MM
If the end time is later or equal to the start time (same day):
durationMinutes = endMinutes − startMinutes
If the end time is earlier than the start time, the tool assumes the interval crosses midnight and adds 24 hours:
durationMinutes = (endMinutes + 24 × 60) − startMinutes
The result is reported as:
- Minutes (integer), and
- H:MM format, obtained by: hours = floor(durationMinutes ÷ 60) and minutes = durationMinutes mod 60, displayed as H:MM with a leading zero for minutes (e.g., 3:05).
4. Validation and rounding
Inputs outside 00:00–23:59 are rejected.
Seconds are not supported; any sub-minute timing should be rounded to the nearest minute before entry.
All durations are exact in minutes; no additional rounding is applied.
5. Clinical use & limitations
Useful for: CPB pump time, cross-clamp time, circulatory arrest time; cardioplegia dosing intervals or ECMO procedure segments; operating room or ICU workflow time stamps.
The calculator does not store dates and cannot distinguish different calendar days; any interval longer than 24 hours must be split manually.
Results are for documentation and workflow support only and do not replace clinical records, perfusion charts, or institutional time-keeping systems. For educational use only. Not medical advice or a regulated medical device.
Heparin Management (CPB)
Calculate an initial loading dose with weight strategy safeguards and optional flow targets; toggle resistance cues when ACT response is low.
Patient parameters
Adult CPBAuto switches to ABW when BMI ≥ 30 to reduce overdose risk.
Auto logic: BMI < 30 → TBW; BMI 30–39 → ABW (0.4 correction); BMI ≥ 40 → ABW (0.3) with obesity safety cues.
Devine IBW: Male = 50 + 0.91 × (cm − 152.4), Female = 45.5 + 0.91 × (cm − 152.4).
ABW 0.4 / 0.3 rules: ABW = IBW + factor × (TBW − IBW); factor 0.4 when BMI 30–39, factor 0.3 when BMI ≥ 40.
Safety cap: Obesity flows/doses use IBW/ABW and may cap BSA to avoid extreme UFH and hemodilution.
Initial dose (u/kg)
Risk factors (check all)
Selecting risk factors does not automatically change dosing. (Reference only)
Next steps (reference)
- Rule out basics: confirm heparin delivery, sampling/ACT device issues, temperature/hemodilution.
- Recheck ACT at 3–5 min; if below target, consider additional UFH per local protocol.
- If inadequate response persists, consider checking AT activity and/or anti-Xa (or heparin concentration) and prepare AT supplementation (FFP if AT concentrate not available) per protocol.
- Special situations (e.g., HIT) → follow institutional DTI protocol.
Enter patient parameters to calculate
Height, weight, and dose are required.