Fluids & blood volume
Follow fluid from the bag into the blood, plasma and crystalloid compartments, then distinguish total circulating volume from gradual conversion.
The current volume function returns the combined retained blood, plasma and saline compartments to ACE. Plasma and crystalloid also convert gradually into the blood compartment while blood volume is below 6 L. Those are separate steps.
Calcium during transfusion: Timing for the first and fourth units · Chloride and gluconate delivery rates.
Where each fluid goes
| Fluid | Initial compartment | Additional behavior |
|---|---|---|
Compatible stored blood | Blood | Adds the admitted volume directly to blood and transfused blood totals |
Compatible fresh blood that meets the fresh blood entry condition | Blood | Fresh blood effectiveness can change flow and conversion |
Plasma | Plasma | Adds platelet count credit in this game model |
Normal saline | Saline / crystalloid | Normal saline exposure also feeds the separate chloride load model |
PlasmaLyte | Saline / crystalloid | Reduces the modeled metabolic acidosis component as admitted fluid arrives |
Esmolol, HTS, magnesium and mannitol premixed bags | Saline / crystalloid carrier volume | Medication or osmotherapy is delivered through its accompanying tracker |
Blood rejected by compatibility/fresh blood conditions | Saline compartment with reaction accounting | Also reduces platelet count and records reaction volume; it is not equivalent to compatible blood |
Fresh blood collection kit | Removes blood from the donor | Collection reverses the bag volume direction |
Only admitted volume receives systemic credit. Leakage can make admitted volume much smaller than the amount removed from the bag. The retained compartments are capped within the shared 6 L capacity, and excess fluid is handled by the overload model.
Conversion rates
When the blood compartment is below 6 L, plasma converts at 0.003 L/s and saline compartment fluid at 0.0007 L/s. The conversion modifier doubles when fresh blood effectiveness exceeds 0.83. Conversion is limited by the available fluid in each source compartment.
| Compartment | Ordinary conversion | With doubled modifier | Ideal time for 1 L at ordinary rate |
|---|---|---|---|
Plasma | 180 mL/min | 360 mL/min | 5 min 33 s |
Saline / crystalloid | 42 mL/min | 84 mL/min | 23 min 49 s |
These times assume 1 L is already present, enough room remains in the blood compartment, and no ongoing losses, additional delivery or competing limits change the state. They are conversion times, not bag administration times.
Why blood loss wording can lag behind a bag
| Observation | Check |
|---|---|
Bag volume decreases, but the response is small | Assess infiltration, compromised sites, ongoing bleeding and whether the fluid is reaching circulation |
Several liters administered without the expected recovery | Check total retained volume, compartment distribution, overload and continued losses. Administered volume alone does not establish retained volume |
Blood specific findings remain poor after crystalloid | Some assessments read the blood compartment directly; Feel Skin is one example |
Plasma or crystalloid is present but the blood compartment is rising gradually | That is the configured conversion path. The combined retained compartments are still included in the volume returned to ACE |
Saturation improves while the patient remains unstable | Oxygen saturation and circulating volume describe different parts of the patient state |
Use the volume trend and repeated assessments together. An emptied bag does not prove the same volume is retained or that all blood compartment findings have recovered.
Conservation at the IV site
Systemic medication dose = concentration × drained volume × admission fraction. The volume and medication calculations share the site’s admission fraction.
| Example | Bag loss | Admitted | Local loss |
|---|---|---|---|
Intact line | 100 mL | 100 mL | 0 mL |
Compromised catheter | 100 mL | 20 mL | 80 mL |
Compromised catheter plus native stage-2 infiltration | 100 mL | 16 mL | 84 mL |
For a 1 mg/mL infusion, the final row corresponds to 16 mg systemic delivery and 84 mg local leakage. This is a calculation example, not a dosing target.
Sources and revision
Checked against ACM Extended source revision 5bce47c on 13 September 2026.
Calcium during blood transfusion
ACME game reference. Start indicated replacement early and control the delivery rate. In these examples, one unit means 500 mL of compatible blood actually admitted to the patient.
First unit and fourth unit
First unit: begin during transfusion
If calcium has not already been supplied, start controlled replacement during the first unit. If that unit finishes untreated, begin promptly. There is no extra grace period after the bag empties: the native HR target penalty starts once the uncleared transfusion burden exceeds 50 mL. This does not mean a patient instantly collapses at 50 mL.
Fourth unit: reassess before or during it
Review earlier calcium, actual delivery and the ongoing blood rate as the fourth unit starts. Arrange further replacement when the accumulating burden and remaining credit require it. If no calcium has been given, do not wait for the fourth bag to finish. The code has no special fourth-unit trigger or mandatory extra dose at that bag number.
CautionPrompt treatment still needs controlled delivery
For the same replacement reference, use 1 g calcium chloride or 3 g calcium gluconate, accounting for calcium already given. Both salts contribute to the same toxicity accumulator. Active transfusion does not disable those separate toxicity checks. Giving both as separate full replacement doses doubles that intended replacement and adds their elemental loads.
Continue reassessment throughout later units. A bag count is a reminder to check calcium, not a measurement of the remaining deficit. Follow pulse/rhythm, pressure, bleeding and line function; the debug calcium values, when available, are game model values.
Chloride and gluconate: how fast?
The following five-minute delivery examples stay below the configured fast-rate threshold and have a modeled steady excess below the toxicity threshold from a zero starting excess. Earlier calcium or simultaneous delivery can change that result. These are amounts reaching circulation, not merely leaving the syringe or bag.
| Salt | Replacement reference | Five-minute delivery | Elemental calcium rate | Ten-minute infusion example |
|---|---|---|---|---|
1 g = 10 mL at 100 mg/mL | 200 mg/min; 2 mL/min undiluted | 54.6 mg/min | 100 mg/min salt; 27.3 mg/min elemental | |
3 g = 30 mL at 100 mg/mL | 600 mg/min; 6 mL/min undiluted | 55.8 mg/min | 300 mg/min salt; 27.9 mg/min elemental |
CautionThe 120-second gluconate default is not a full-dose safety limit
The documented Hardcore default is 300 s for chloride and 120 s for gluconate. But 3 g gluconate over 120 s = 139.5 mg/min elemental calcium, above the configured 100 mg/min fast-rate onset. For that full 3 g reference, a 300 s delivery gives 55.8 mg/min instead. Check the actual selected volume and concentration each time.
Rate and total exposure both matter
Fast-rate toxicity starts above 100 mg/min elemental calcium and reaches full rate severity at 280 mg/min. The separate excess accumulator starts causing toxicity above 1 mg/dL of modeled excess; 4 mg/dL reaches full excess severity. The worse effect applies. Those are excess-proxy values, not measured ionized calcium.
Do not use the mathematical boundary as a target
At the 100 mg/min elemental boundary, 1 g chloride takes 2.73 min and 3 g gluconate takes 2.79 min. That only addresses the rate term. It does not establish a safe correction duration, because accumulation and prior doses still apply. The five-minute examples produce lower sustained inputs, 54.6 and 55.8 mg/min.
The Hardcore syringe timer is limited to 300 s. For a longer delivery, use a controlled prepared infusion or deliberately separated measured portions. A diluted bag needs its own concentration and admitted-flow calculation; the undiluted mL/min values above do not transfer to it. See the drip calculator and slow push controls.
What an untreated transfusion changes
Early native HR target penalty
Above 0.05 L of uncleared transfusion burden, the native adjustment is minus burden in liters / 0.05 bpm. Exactly 50 mL does not pass the strict greater-than check. This adjustment feeds the HR update with other effects; it is not a promise that the displayed pulse immediately drops by that exact amount.
Additional ACME calcium deficit
By default, the additional circulation model starts accruing deficit above 1 L of remaining burden: 0.18 normalized calcium per extra liter, offset by 0.12 per gram of cumulative CaCl₂-equivalent credit. Low calcium adds bleeding amplification, pressure suppression and eventually reduced pressor response. These thresholds are separate from the early 50 mL HR rule.
The table assumes no calcium, no prior credit, no burden clearance and 500 mL actually admitted per unit. Pressure entries are the calcium model's suppression targets, applied gradually through circulation, not guaranteed changes on the cuff.
| Blood admitted | Native HR target adjustment | Normalized calcium | Calcium pressure suppression target | Calcium bleeding multiplier |
|---|---|---|---|---|
Unit 1: 0.5 L | −10 bpm | 1.00 | 0 mmHg | 1.00× |
Unit 2: 1.0 L | −20 bpm | 1.00 | 0 mmHg | 1.00× |
Unit 3: 1.5 L | −30 bpm | 0.91 | 3.6 mmHg | 1.08× |
Unit 4: 2.0 L | −40 bpm | 0.82 | 7.2 mmHg | 1.16× |
At the untreated fourth-unit example, calcium also reduces the pressor-response multiplier to about 0.94. Hypothermia, acidosis, shock and other active conditions can add their own effects. If earlier calcium has been delivered, use the remaining burden and credit, not this untreated table.
How long does correction take?
While both transfusion burden and native calcium credit are positive, the native loop removes burden at up to 0.005 L/s = 300 mL/min. Without that calcium credit, this loop has no passive clearance with time. A stopped blood bag therefore does not start a countdown that clears its burden by itself.
| Existing burden | No more blood entering | Blood continues at 100 mL/min |
|---|---|---|
0.5 L | About 1 min 40 s | About 2 min 30 s to catch up |
2.0 L | About 6 min 40 s | About 10 min to catch up |
These arithmetic examples assume enough usable calcium credit throughout and ordinary ticking. They are burden-clearance times, not medication push times or guaranteed patient-recovery times. With incoming blood, the ideal net reduction is 300 minus admitted blood mL/min. At or above 300 mL/min combined admission, this clearance path cannot reduce an existing backlog while that input continues.
A warmer's nominal setting is 100 mL/min, but actual admission still depends on perfusion, line flow and leakage. At an actual 100 mL/min, an untreated line crosses the 50 mL threshold just after 30 seconds and delivers 500 mL in five minutes. Pressure recovery also eases over time, and the medication cards' 5- and 7-minute effect peaks are separate from burden clearance.
Why the next dose depends on reassessment
Native clearing credit
The first gram of CaCl₂-equivalent medication adds 2.5 native calcium-count units; later grams add 2 each, with a count cap of 3 on the native update. The first-gram bonus is spread across partial deliveries. Three grams of gluconate supplies approximately the same replacement credit as one gram of chloride.
Credit is not a fixed number of protected blood bags
While burden is positive, calcium count can be spent at 0.005 per second even when less than 0.005 L of burden is available to remove that tick. A full 2.5-count pool lasts about 8 min 20 s of continuous active clearing. Credit spent during administration reduces what remains afterward. Remaining credit, delivery timing, pauses and the blood rate change the result.
The separate ACME CaCl₂-equivalent total contributes to the normalized calcium calculation; it is not the same variable as the spendable native count or the toxicity excess accumulator. Check the response and cumulative amount before repeating, especially if changing salts. On continued transfusion, a first/fourth-unit reminder is useful for reassessment, but it cannot guarantee adequate replacement or rule out excessive calcium.
Main, Hardcore and actual delivery
In gameCheck the mod build and mode
The reviewed main revision 5416332 uses the recorded manual delivery duration for calcium's custom rate input. The reviewed dev revision a9ae90c includes Hardcore timing: with Hardcore Medications on, the selected duration drives delivery; with it off, the custom bolus rate input uses at least 300 s for chloride and 180 s for gluconate. These internal normal-mode windows are not visible administration timers, and do not guarantee that any amount is safe. Actual infusion-rate and accumulation effects remain active.
Replacement credit starts with medication admitted to the patient. A prepared syringe, leaked dose or dose parked in a flush-required line is not delivered replacement. Check the selected site and flush when required. Persistent Hardcore pushes and their flush handling are explained in the IV access guide.
Sources and revision
Calcium review: main 5416332 and dev a9ae90c, 15 September 2026. The inspected native burden/HR rules, replacement callback and calcium toxicity equations agree between these revisions; manual timing differs as described above. Native HR adjustment · Admitted blood, clearance and warmer flow · Native calcium credit · Deficit defaults · Circulation and excess model · Toxicity defaults · Salt equivalence and flushing · Main manual exposure · Dev normal-mode windows · Hardcore syringe defaults.