Evaluating Extravascular Lung Water in Sepsis: Three Lung-Ultrasound Techniques Compared against Transpulmonary Thermodilution

Pattarin Pirompanich; Dimitrios Karakitsos; Abdulrahman Alharthy; Lawrence Marshall Gillman; Michael Blaivas; Brian M Buchanan; Peter G Brindley; Anan Wattanathum

doi:10.4103/ijccm.IJCCM_256_18

Evaluating Extravascular Lung Water in Sepsis: Three Lung-Ultrasound Techniques Compared against Transpulmonary Thermodilution

Indian J Crit Care Med. 2018 Sep;22(9):650-655. doi: 10.4103/ijccm.IJCCM_256_18.

Authors

Pattarin Pirompanich¹, Dimitrios Karakitsos^{2

3

4}, Abdulrahman Alharthy³, Lawrence Marshall Gillman⁵, Michael Blaivas², Brian M Buchanan⁶, Peter G Brindley⁶, Anan Wattanathum⁷

Affiliations

¹ Department of Medicine, Division of Pulmonary and Critical Care Medicine, Faculty of Medicine, Thammasat University, Pathumthani, Thailand.
² Department of Medicine, University of South Carolina, School of Medicine, Columbia, SC, USA.
³ Department of ICU, King Saud Medical City, Riyadh, KSA.
⁴ Department of Critical Care Medicine, Keck Medical School, USC, CA, USA.
⁵ Department of Surgery, University of Manitoba, Winnipeg, Manitoba, Canada.
⁶ Department of Critical Care Medicine, University of Alberta, Alberta, Canada.
⁷ Department of Medicine, Phramongkutklao Hospital, Bangkok, Thailand.

Abstract

Background: Excessive extravascular lung water (EVLW) is associated with increased morbidity and mortality. We compared three lung-ultrasound (L-US) techniques against the reference-standard transpulmonary thermodilution (TPTD) technique to access EVLW.

Materials and methods: This was a prospective, single-blind, cross-sectional study. Forty-four septic patients were enrolled. EVLW index was measured by the TPTD method, and an index of ≥10 mL/kg was considered diagnostic of pulmonary edema. EVLW index was then compared to three established bedside L-US protocols that evaluate sonographic B-lines: (1) a 28-zone protocol (total B-line score [TBS]) (2) a scanning 8-region examination, and (3) a 4-point examination.

Results: Eighty-nine comparisons were obtained. A statistically significant positive correlation was found between L-US TBS and an EVLW index ≥10 mL/kg (r = 0.668,P < 0.001). The 28-zone protocol score ≥39 has a sensitivity of 81.6% and a specificity of 76.5% to define EVLW index ≥10 mL/kg. In contrast, the positive 4-point examination and scanning 8-regions showed low sensitivity (23.7% and 50.0%, respectively) but high specificity (96.1% and 88.2%, respectively). Ten patients with a total of 21 comparisons met criteria for acute respiratory distress syndrome (ARDS). In this subgroup, only the TBS had statistically significant positive correlation to EVLW (r = 0.488,P = 0.025).

Conclusion: L-US is feasible in patients with severe sepsis. In addition, L-US 28-zone protocol demonstrated high specificity and better sensitivity than abbreviated 4- and 8-zone protocols. In ARDS, the L-US 28-zone protocol was more accurate than the 4- and 8-zone protocols in predicting EVLW. Consideration of limitations of the latter protocols may prevent clinicians from reaching premature conclusions regarding the prediction of EVLW.

Trial registration: ISRCTN11419081. Registered 4 February 2015 retrospectively.

Keywords: Acute interstitial syndrome; B-lines; extravascular lung water; lung ultrasound; transpulmonary thermodilution.