[Pressure monitoring in continuous renal replacement therapy]

Continuous renal replacement therapy (CRRT) has experienced significant advances that have lead to an increase of its indications and improved the technology used in continued pressures monitoring.

This study has aimed to discover if there are any associations between the increase of the circuit pressures and their duration.

A prospective, longitudinal analytic pilot study was conducted in an Intensive Care Unit of a university hospital from October 2008 to April 2009. The study analyzed the patient's information with CRRT and the hourly values of entry pressure (EP), comeback pressure (CP), transmembrane pressure (TMP) and pre-filter pressure (PFP). The Spearman correlation and the Student's T test were used.

The study analyzed 44 sets corresponding to 11 patients (45.5% men and 54.5% women) with a life expectancy of 62 years. The same light catheter GamCath (11 French) and Continuous Venovenous Hemodiafiltration (CVVHDF) therapy were used in all patients. The mean duration of the circuits was 39 h. Mean, median, maximum and minimum values of the sample pressures were: EP:-52.17; -52.57; 160; -256 (millimeters of mercury) mmHg]; CP: (98.6; 95.3; 323; -2 mmHg); TMP: (58.57; 58.52; 245; -20 mmHg) and PFP: (161.76; 159.42; 375; -13 mmHg), respectively.

A negative correlation was demonstrated between the duration of the sets and the mean CP and PFP. The sample obtained circuits withdrawn due to finished treatment (72 h), and by coagulation or changes in pressures.