Editing Cardiac output (section)

===== Uncalibrated, pre-estimated demographic data-free – PRAM =====
Pressure Recording Analytical Method (PRAM), estimates ''Q'' from the analysis of the pressure wave profile obtained from an arterial catheter—radial or femoral access. This PP waveform can then be used to determine ''Q''. As the waveform is sampled at 1000&nbsp;Hz, the detected pressure curve can be measured to calculate the actual beat-to-beat stroke volume. Unlike FloTrac, neither constant values of impedance from external calibration, nor form pre-estimated [[in vivo]] or [[in vitro]] data, are needed.{{cn|date=July 2024}}

PRAM has been validated against the considered gold standard methods in stable condition<ref>{{cite journal | vauthors = Romano SM, Pistolesi M | title = Assessment of cardiac output from systemic arterial pressure in humans | journal = Critical Care Medicine | volume = 30 | issue = 8 | pages = 1834–41 | date = August 2002 | pmid = 12163802 | doi = 10.1097/00003246-200208000-00027 | s2cid = 12100251 }}</ref> and in various haemodynamic states.<ref>{{cite journal | vauthors = Scolletta S, Romano SM, Biagioli B, Capannini G, Giomarelli P | title = Pressure recording analytical method (PRAM) for measurement of cardiac output during various haemodynamic states | journal = British Journal of Anaesthesia | volume = 95 | issue = 2 | pages = 159–65 | date = August 2005 | pmid = 15894561 | doi = 10.1093/bja/aei154 | doi-access = free }}</ref> It can be used to monitor pediatric and mechanically supported patients.<ref>{{cite journal | vauthors = Calamandrei M, Mirabile L, Muschetta S, Gensini GF, De Simone L, Romano SM | title = Assessment of cardiac output in children: a comparison between the pressure recording analytical method and Doppler echocardiography | journal = Pediatric Critical Care Medicine | volume = 9 | issue = 3 | pages = 310–12 | date = May 2008 | pmid = 18446106 | doi = 10.1097/PCC.0b013e31816c7151 | s2cid = 25815656 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Scolletta S, Gregoric ID, Muzzi L, Radovancevic B, Frazier OH | title = Pulse wave analysis to assess systemic blood flow during mechanical biventricular support | journal = Perfusion | volume = 22 | issue = 1 | pages = 63–66 | date = January 2007 | pmid = 17633137 | doi = 10.1177/0267659106074784 | s2cid = 32129645 }}</ref>

Generally monitored haemodynamic values, fluid responsiveness parameters and an exclusive reference are provided by PRAM: Cardiac Cycle Efficiency (CCE). It is expressed by a pure number ranging from 1 (best) to -1 (worst) and it indicates the overall heart-vascular response coupling. The ratio between heart performance and consumed energy, represented as CCE "stress index", can be of paramount importance in understanding the patient's present and future courses.<ref>{{cite web | vauthors = Scolletta S, Romano SM, Maglioni H |year=2005 |title=Left ventricular performance by PRAM during cardiac surgery |page=S157}} in {{cite journal |year=2005 |title=OP 564–605 |journal=Intensive Care Medicine |volume=31 |issue=Suppl 1 |pages=S148–58 |doi=10.1007/s00134-005-2781-3|s2cid=30752685 }}</ref>