diff --git a/addons/medical_treatment/XEH_PREP.hpp b/addons/medical_treatment/XEH_PREP.hpp
index 9d779d3154..a6e460be46 100644
--- a/addons/medical_treatment/XEH_PREP.hpp
+++ b/addons/medical_treatment/XEH_PREP.hpp
@@ -49,6 +49,7 @@ PREP(healTime);
 PREP(isBeingCarried);
 PREP(isBeingDragged);
 PREP(onMedicationUsage);
+PREP(calculateBlood);
 
 // items
 PREP(checkItems);
diff --git a/addons/medical_treatment/functions/fnc_calculateBlood.sqf b/addons/medical_treatment/functions/fnc_calculateBlood.sqf
new file mode 100644
index 0000000000..c1c53265fa
--- /dev/null
+++ b/addons/medical_treatment/functions/fnc_calculateBlood.sqf
@@ -0,0 +1,30 @@
+/*
+ * Author: Zakant
+ * Calculate the blood loost and blood volume for a unit. Used from CPR to simulate a heart rate while in cardiac arrest
+ *
+ * Arguments:
+ * 0: The unit <OBJECT>
+ *
+ * Return Value:
+ * NONE
+ *
+ * Public: No
+ */
+#include "script_component.hpp"
+
+params["_unit"];
+
+// We will just simulate blood flow for now!
+private _lastTimeUpdated = _unit getVariable [QEGVAR(medical,lastTimeUpdated), CBA_missionTime];
+private _deltaT = CBA_missionTime - _lastTimeUpdated;
+
+private _lastTimeValuesSynced = _unit getVariable [QEGVAR(medical,lastMomentValuesSynced), 0];
+private _syncValues = (CBA_missionTime - _lastTimeValuesSynced) >= (10 + floor(random(10)));
+
+_unit setVariable [QEGVAR(medical,lastTimeUpdated), CBA_missionTime];
+if (_deltaT != 0) then {
+  private _change = ([_unit, _deltaT, _syncValues] call EFUNC(medical,getBloodVolumeChange));
+  private _bloodVolume = (_unit getVariable [QEGVAR(medical,bloodVolume), DEFAULT_BLOOD_VOLUME]) + _change ;
+  _bloodVolume = 0 max _bloodVolume min DEFAULT_BLOOD_VOLUME;
+  _unit setVariable  [QEGVAR(medical,bloodVolume), _bloodVolume, _syncValues];
+};