Diaphragm thickening in cardiac surgery: a perioperative prospective ultrasound study

Pierre Moury (1) , Adrien Cuisinier (2) , Michel Durand (2) , Jean-Luc Bosson (3, 1) , Olivier Chavanon (4, 1) , Jean-François Payen (5) , Samir Jaber (6, 7) , Pierre Albaladejo (3, 1)

1 CHUGA - Centre Hospitalier Universitaire [CHU Grenoble]
2 UGA UFRM - Université Grenoble Alpes - UFR Médecine
3 TIMC-IMAG-ThEMAS - Techniques pour l'Evaluation et la Modélisation des Actions de la Santé
4 Clinique de chirurgie cardiaque
5 GIN - [GIN] Grenoble Institut des Neurosciences
6 CHRU Montpellier - Centre Hospitalier Régional Universitaire [Montpellier]
7 PhyMedExp - Physiologie & médecine expérimentale du Cœur et des Muscles [U 1046]

Background: Diaphragm paresis is common after cardiac surgery and may delay the weaning from the ventilator. Our objective was to evaluate diaphragm thickening during weaning and secondly the muscle thickness as a marker of myotrauma. Methods: Patients undergoing elective cardiac surgery were prospectively included. Ultrasonic index of right hemidiaphragm thickening fraction (TF) was measured as a surrogate criterion of work of breathing. A TF < 20% was defined as a low diaphragm thickening. Measurements of TF were performed during three periods to study diaphragm thickening evolution defined by the difference between two consecutive time line point: preoperative (D − 1), during a spontaneous breathing trial (SBT) in the intensive care unit and postoperative (D + 1). We studied three patterns of diaphragm thickness at end expiration evolution from D − 1 to D + 1: > 10% decrease, stability and > 10% increase. Demographical data, length of surgery, type of surgery, ICU length of stay (LOS) and extubation failure were collected. Results: Of the 100 consecutively included patients, 75 patients had a low diaphragm thickening during SBT. Compared to TF values at D − 1 (36% ± 18), TF was reduced during SBT (17% ± 14) and D + 1 (12% ± 11) (P < 0.0001). Thickness and TF did not change according to the type of surgery or cooling method. TF at SBT was correlated to the length of surgery (both r = − 0.4; P < 0.0001). Diaphragm thickness as continuous variable did not change over time. Twenty-eight patients (42%) had a > 10% decrease thickness, 19 patients (29%) stability and 19 patients (28%) in > 10% increase, and this thickness evolution pattern was associated with: a longer LOS 3 days [2–5] versus 2 days [2–4] and 2 days [2], respectively (ANOVA P = 0.046), and diaphragm thickening evolution (ANOVA P = 0.02). Two patients experience extubation failure. Conclusion: These findings indicate that diaphragm thickening is frequently decreased after elective cardiac surgery without impact on respiratory outcome, whereas an altered thickness pattern was associated with a longer length of stay in the ICU. Contractile activity influenced thickness evolution.

Mots clés: Mechanical ventilation; Weaning; Muscle; Cardiac surgery

Domaines: Cardiologie et système cardiovasculaire; Chirurgie

Pierre Moury, Adrien Cuisinier, Michel Durand, Jean-Luc Bosson, Olivier Chavanon, et al.. Diaphragm thickening in cardiac surgery: a perioperative prospective ultrasound study. Annals of Intensive Care, 2019, 9, pp.50. ⟨10.1186/s13613-019-0521-z⟩. ⟨hal-02112190⟩