Changes in BP induced by passive leg raising predict response to fluid loading in critically ill patients.
OBJECTIVE
To test the hypothesis that passive leg raising (PLR) induces changes in arterial pulse pressure that can help to predict the response to rapid fluid loading (RFL) in patients with acute circulatory failure who are receiving mechanical ventilation.


METHODS
Prospective clinical study.


METHODS
Two medical ICUs in university hospitals.


METHODS
Thirty-nine patients with acute circulatory failure who were receiving mechanical ventilation and had a pulmonary artery catheter in place.


METHODS
PLR for > 4 min and a subsequent 300-mL RFL for > 20 min.


RESULTS
Radial artery pulse pressure (PPrad), heart rate, right atrial pressure, pulmonary artery occlusion pressure (PAOP), and cardiac output were measured invasively in a population of 15 patients at each phase of the study procedure (i.e., before and during PLR, and then before and after RFL). PPrad, PAOP, and stroke volume (SV) significantly increased in patients performing PLR. These changes were rapidly reversible when the patients' legs were lowered. Changes in PPrad during PLR were significantly correlated with changes in SV during PLR (r = 0.77; p < 0.001). Changes in SV induced by PLR and by RFL were significantly correlated (r = 0.89; p < 0.001). Finally, PLR-induced changes in PPrad were significantly correlated to RFL-induced changes in SV (r = 0.84; p < 0.001). In a second population of 24 patients, we found the same relationship between PLR-induced changes in PPrad and RFL-induced changes in SV (r = 0.73; p < 0.001).


CONCLUSIONS
The response to RFL could be predicted noninvasively by a simple observation of changes in pulse pressure during PLR in patients with acute circulatory failure who were receiving mechanical ventilation.
Boulain
Thierry
T
Service de Réanimation Médicale, Hôpital de Bicêtre, Faculté de Médecine Paris-Sud, Paris, France. boulain@hotmail.com
Achard
Jean-Michel
JM
Teboul
Jean-Louis
JL
Richard
Christian
C
Perrotin
Dominique
D
Ginies
Guy
G
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000502:physiology*; D001810:Blood Volume / Q000502:physiology*; D003422:Critical Care; D005260:Female; D005440:Fluid Therapy; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007866:Leg / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D011187:Posture; D011311:Pressoreceptors / Q000503:physiopathology; D012121:Respiration, Artificial; D012769:Shock / Q000503:physiopathology / Q000628:therapy