Norepinephrine weaning in septic shock patients by closed loop control based on fuzzy logic

Lapostolle Frédéric, Merouani Mehdi, Guignard Bruno, Vincent François, Borron, Karoubi Philippe, Fosse Jean-Philippe, Yves Cohen, Clec'H Christophe, Vicaut Eric, Marbeuf-Gueye Carole, Adnet Frédéric

Description

The rate of weaning of vasopressors drugs is usually an empirical choice made by the treating in critically ill patients. We applied fuzzy logic principles to modify intravenous norepinephrine (noradrenaline) infusion rates during norepinephrine infusion in septic patients in order to reduce the duration of shock. Methods Septic patients were randomly assigned to norepinephrine infused either at the clinician's discretion (control group) or under closed-loop control based on fuzzy logic (fuzzy group). The infusion rate changed automatically after analysis of mean arterial pressure in the fuzzy group. The primary end-point was time to cessation of norepinephrine. The secondary end-points were 28-day survival, total amount of norepinephine infused and duration of mechanical ventilation. Results Nineteen patients were randomly assigned to fuzzy group and 20 to control group. Weaning of norepinephrine was achieved in 18 of the 20 control patients and in all 19 fuzzy group patients. Median (interquartile range) duration of shock was significantly shorter in the fuzzy group than in the control group (28.5 [20.5 to 42] hours versus 57.5 [43.7 to 117.5] hours; P < 0.0001). There was no significant difference in duration of mechanical ventilation or survival at 28 days between the two groups. The median (interquartile range) total amount of norepinephrine infused during shock was significantly lower in the fuzzy group than in the control group (0.6 [0.2 to 1.0] μg/kg versus 1.4 [0.6 to 2.7] μg/kg; P < 0.01). Conclusions Our study has shown a reduction in norepinephrine weaning duration in septic patients enrolled in the fuzzy group. We attribute this reduction to fuzzy control of norepinephrine infusion. Trial registration Trial registration: Clinicaltrials.gov NCT00763906.

Informations

• Publié par: biomed
• Publié le: 01 janvier 2008
• Nombre de lectures: 14
• Langue: English

Extrait

Available onlinehttp://ccforum.com/content/12/6/R155

Vol 12 No 6 Open Access Research Norepinephrine weaning in septic shock patients by closed loop control based on fuzzy logic 1 2 3 4 3 Mehdi Merouani , Bruno Guignard , François Vincent , Stephen W Borron , Philippe Karoubi , 3 3 3 5 6 JeanPhilippe Fosse , Yves Cohen , Christophe Clec'h , Eric Vicaut , Carole MarbeufGueye , 1 1 Frederic Lapostolle and Frederic Adnet

1 Samu 93 – EA 3409, Université Paris 13, Hôpital Avicenne, Rue de Stalingrad, 93000 Bobigny, France 2 Département d'Anesthésie et de Réanimation, Hôpital Ambroise Paré, Avenue CharlesdeGaulle, 92100 Boulogne Billancourt, France 3 Service de Réanimation, Hôpital Avicenne, Rue de Stalingrad, 93000 Bobigny, France 4 Department of Surgery (Emergency Medicine), University of Texas Health Science Center at San Antonio, Medical Drive, San Antonio, TX 78229, USA 5 Unité de Recherche Clinique, Hôpital Fernand Widal, Rue Ambroise Paré, 75475 Paris Cedex, France 6 BioMoCeTi, UMR 7033, UFR SMBH, Université Paris 13, Rue Marcel Cachin, 93000 Bobigny, France

Corresponding author: Frederic Adnet, [e-mail]

Received: 15 Oct 2008 Revisions requested: 12 Nov 2008 Revisions received: 30 Nov 2008 Accepted: 9 Dec 2008 Published: 9 Dec 2008

Critical Care2008,12:R155 (doi:10.1186/cc7149) This article is online at: http://ccforum.com/content/12/6/R155 © 2008 Merouaniet al.; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Introduction The rate of weaning of vasopressors drugs is usually an empirical choice made by the treating in critically ill patients. We applied fuzzy logic principles to modify intravenous norepinephrine (noradrenaline) infusion rates during norepinephrine infusion in septic patients in order to reduce the duration of shock.

Methodspatients were randomly assigned to Septic norepinephrine infused either at the clinician's discretion (control group) or under closedloop control based on fuzzy logic (fuzzy group). The infusion rate changed automatically after analysis of mean arterial pressure in the fuzzy group. The primary endpoint was time to cessation of norepinephrine. The secondary endpoints were 28day survival, total amount of norepinephine infused and duration of mechanical ventilation.

Results Nineteen patients were randomly assigned to fuzzy group and 20 to control group. Weaning of norepinephrine was

Introduction Despite advances in critical care, the death rate from severe sepsis remains approximately 30% to 50%. In 1995, severe sepsis accounted for 9.3% of all deaths in the USA [1]. It is generally agreed that fluid resuscitation and vasopressors should be initiated promptly to treat shock and organ failure,

ICU: intensive care unit; MAP: mean arterial pressure.

achieved in 18 of the 20 control patients and in all 19 fuzzy group patients. Median (interquartile range) duration of shock was significantly shorter in the fuzzy group than in the control group (28.5 [20.5 to 42] hours versus 57.5 [43.7 to 117.5] hours;P< 0.0001). There was no significant difference in duration of mechanical ventilation or survival at 28 days between the two groups. The median (interquartile range) total amount of norepinephrine infused during shock was significantly lower in the fuzzy group than in the control group (0.6 [0.2 to 1.0]μg/kg versus 1.4 [0.6 to 2.7]μg/kg;P< 0.01).

Conclusions Our study has shown a reduction in norepinephrine weaning duration in septic patients enrolled in the fuzzy group. We attribute this reduction to fuzzy control of norepinephrine infusion.

Trial registration NCT00763906.

Trial

registration:

Clinicaltrials.gov

and rapidly restore the mean arterial pressure (MAP) to 60 to 90 mmHg [2,3].

The vasopressor in most common use is norepinephrine (noradrenaline) but, because of its weak inotropic effect and concerns about regional blood flow, dobutamine is often administered concomitantly. As soon as haemodynamic varia

Page 1 of 8 (page number not for citation purposes)