Presión media de llenado sistémico: ¿es el parámetro ideal para evaluar precarga óptima? / Mean systemic filling pressure: Is the ideal parameter to evaluate optimal preload?

Uno de los retos para el cardiólogo es conseguir una volemia óptima, es decir, mejorar el gasto cardiaco, evitando un exceso de volemia que pudiera favorecer un pronóstico negativo. Actualmente se sabe que el balance positivo se asocia con un incremento en la mortalidad; en la actualidad contamos con diversos parámetros para evaluar la precarga; sin embargo, ninguno es altamente fidedigno. El objetivo del presente artículo de revisión es dar un recordatorio de este concepto fisiológico así como sus utilidades en el monitoreo del paciente.

One challenge for the cardiologist is to achieve optimal blood volume for to improve cardiac output, and avoid excessive blood volume that could favor a negative prognosis. Now is known that the positive balance is associated with increased mortality; today we have different standards for assessing preload yet none is highly reliable; the objective of this review is to give a reminder of its physiological concept and profits in patient monitoring.

Effects of spontaneous agonal respiration on coronary perfusion pressure during untreated cardiac arrest in swine model / 中华急诊医学杂志

Objective To investigate the effects of spontaneous agonal respiration on coronary perfusion pressure (CPP) during untreated cardiac arrest (ventricular fibrillation) in swine model.Methods Ten male healthy domestic swines (25.0 ± 1.5) kg were anaesthetised,intubated and mechanically ventilated.The catheterizations were separately inserted into the right atrium and thoracic aorta to monitor aortic pressure (AOP) and right atrial pressure (RAP).A pacing electrode was inserted into the right ventricle to induce ventricular fibrillation (VF).VF was induced by intra-ventricular stimulation withalternating electric current and untreated for 8 minutes.AOP and RAP were recorded until respiratory activity ceased.The CPP before and after agonal respiration was calculated and analyzed by paired-sample T test.Results All animals presented with agonal respiration from 1 to 6 minutes after VF during the first attempt.The CPP was (7.18 ±4.22) mmHg at 1 sec before agonal respiration,(11.78 ±5.16) mmHg at 0 sec after agonal respiration,(8.75 t:4.38) mmHg at 5 sec after agonal respiration and (8.23 ± 4.55)mmHg at 6 sec after agonal respiration.The CPP at 0 sec after agonal respiration was higher than that before agonal respiration (t =-3.140,P =0.012).The CPP at 5 sec after agonal respiration was higher than that at 1 sec before agonal respiration (t =-2.828,P =0.020).There was no difference in CPP between at 6 sec after agonal respiration and at 1 sec before agonal respiration (t =-1.778,P =0.109).Conclusions Agonal respiration accompanies ventricular fibrillation.After agonal respiration,the coronary perfusion pressure is increased for 5 seconds being in favor of cardiaopulmonary resuscitation.