Comparison of two non-bronchoscopic methods for evaluating inflammation in patients with acute hypoxaemic respiratory failure

Colucci Giuseppe, Domenighetti Guido, Della, Bonilla Josè, Limoni Costanzo, Matthay, Martin

Description

The simple bedside method for sampling undiluted distal pulmonary edema fluid through a normal suction catheter (s-Cath) has been experimentally and clinically validated. However, there are no data comparing non-bronchoscopic bronchoalveolar lavage (mini-BAL) and s-Cath for assessing lung inflammation in acute hypoxaemic respiratory failure. We designed a prospective study in two groups of patients, those with acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) and those with acute cardiogenic lung edema (ACLE), designed to investigate the clinical feasibility of these techniques and to evaluate inflammation in both groups using undiluted sampling obtained by s-Cath. To test the interchangeability of the two methods in the same patient for studying the inflammation response, we further compared mini-BAL and s-Cath for agreement of protein concentration and percentage of polymorphonuclear cells (PMNs). Methods Mini-BAL and s-Cath sampling was assessed in 30 mechanically ventilated patients, 21 with ALI/ARDS and 9 with ACLE. To analyse agreement between the two sampling techniques, we considered only simultaneously collected mini-BAL and s-Cath paired samples. The protein concentration and polymorphonuclear cell (PMN) count comparisons were performed using undiluted sampling. Bland-Altman plots were used for assessing the mean bias and the limits of agreement between the two sampling techniques; comparison between groups was performed by using the non-parametric Mann-Whitney-U test; continuous variables were compared by using the Student t-test, Wilcoxon signed rank test, analysis of variance or Student-Newman-Keuls test; and categorical variables were compared by using chi-square analysis or Fisher exact test. Results Using protein content and PMN percentage as parameters, we identified substantial variations between the two sampling techniques. When the protein concentration in the lung was high, the s-Cath was a more sensitive method; by contrast, as inflammation increased, both methods provided similar estimates of neutrophil percentages in the lung. The patients with ACLE showed an increased PMN count, suggesting that hydrostatic lung edema can be associated with a concomitant inflammatory process. Conclusions There are significant differences between the s-Cath and mini-BAL sampling techniques, indicating that these procedures cannot be used interchangeably for studying the lung inflammatory response in patients with acute hypoxaemic lung injury.

Informations

• Publié par: biomed
• Publié le: 01 janvier 2009
• Nombre de lectures: 11
• Langue: English

Extrait

Available onlinehttp://ccforum.com/content/13/4/R134

Vol 13 No 4 Open Access Research Comparison of two nonbronchoscopic methods for evaluating inflammation in patients with acute hypoxaemic respiratory failure 1 1 2 3 Giuseppe Colucci *, Guido Domenighetti *, Roberto Della Bruna , Josè Bonilla , 4 5 6 Costanzo Limoni , Michael A Matthay and Thomas R Martin

1 Multidisciplinary Intensive Care Unit, Regional Hospital EOC, Via Ospedale 14, Locarno 6600, Switzerland 2 EOLAB, Ente Ospedaliero Cantonale, Viale Officina 3, Bellinzona 6500, Switzerland 3 Cantonal Pathological Institute, Lab for Clinical Cytology, Via A. Franzoni 45, Locarno 6600, Switzerland 4 Department for Social Sciences, University of Applied Sciences and Arts of Southern Switzerland, Le Gerre, Manno 6928, Switzerland 5 Departments of Medicine and Anaesthesia, Cardiovascular Research Institute, University of California, San Francisco, 505 Parnassus Ave, M917, Box 0624, San Francisco, CA 94143, USA 6 Medical Research Service of the VA Puget Sound Medical Center and the Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of Washington, Seattle, 1660 S. Columbian Way, Seattle, WA 98108, USA * Contributed equally

Corresponding author: Guido Domenighetti, [e-mail]

Received: 19 Apr 2009 Revisions requested: 4 Jun 2009 Revisions received: 28 Jul 2009 Accepted: 11 Aug 2009 Published: 11 Aug 2009

Critical Care2009,13:R134 (doi:10.1186/cc7995) This article is online at: http://ccforum.com/content/13/4/R134 © 2009 Colucciet 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

IntroductionThe simple bedside method for sampling undiluted distal pulmonary edema fluid through a normal suction catheter (sCath) has been experimentally and clinically validated. However, there are no data comparing nonbronchoscopic bronchoalveolar lavage (miniBAL) and sCath for assessing lung inflammation in acute hypoxaemic respiratory failure. We designed a prospective study in two groups of patients, those with acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) and those with acute cardiogenic lung edema (ACLE), designed to investigate the clinical feasibility of these techniques and to evaluate inflammation in both groups using undiluted sampling obtained by sCath. To test the interchangeability of the two methods in the same patient for studying the inflammation response, we further compared mini BAL and sCath for agreement of protein concentration and percentage of polymorphonuclear cells (PMNs).

Methodsand sCath sampling was assessed in 30 MiniBAL mechanically ventilated patients, 21 with ALI/ARDS and 9 with ACLE. To analyse agreement between the two sampling techniques, we considered only simultaneously collected mini BAL and sCath paired samples. The protein concentration and

polymorphonuclear cell (PMN) count comparisons were performed using undiluted sampling. BlandAltman plots were used for assessing the mean bias and the limits of agreement between the two sampling techniques; comparison between groups was performed by using the nonparametric Mann WhitneyU test; continuous variables were compared by using the Student ttest, Wilcoxon signed rank test, analysis of variance or StudentNewmanKeuls test; and categorical variables were compared by using chisquare analysis or Fisher exact test.

Results Using protein content and PMN percentage as parameters, we identified substantial variations between the two sampling techniques. When the protein concentration in the lung was high, the sCath was a more sensitive method; by contrast, as inflammation increased, both methods provided similar estimates of neutrophil percentages in the lung. The patients with ACLE showed an increased PMN count, suggesting that hydrostatic lung edema can be associated with a concomitant inflammatory process.

ACLE: acute cardiogenic lung oedema; ALI: acute lung injury; ARDS: acute respiratory distress syndrome; bBAL: bronchoscopic bronchoalveolar lavage; CI: confidence interval; FiO : fraction of inspired oxygen; Fr: French; HR: heart rate; ICU: intensive care unit; IL: interleukin; LIS: Lung Injury 2 Score; LOS: length of stay; miniBAL: nonbronchoscopic bronchoalveolar lavage; PaO : partial pressure of oxygen in arterial blood; PEEP: positive 2 endexpiratory pressure; PMN: polymorphonuclear cell; P : peak pressure; P : plateau pressure; RBC: red blood cell; SAP: systemic arterial pres peak plat sure; SAPS II: Simplified Acute Physiology Score II; sCath: suction catheter; SpO : pulsed oxygen saturation; V : minute ventilation; V : expiratory 2 E t tidal volume; WBC: white blood cell.

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