Predicting Weaning Outcome in Mechanically Ventilated ICU Patients Using the Rapid Shallow Breathing Index, Ultrasound-Guided Diaphragm Thickening Fraction, and Their Combination: A Prospective Cohort Study
Keywords:
Weaning; Mechanical ventilation;, Rapid shallow breathing index; Diaphragm thickening fraction; Diaphragm ultrasound; Spontaneous breathing trial.Abstract
Background: Timely liberation from mechanical ventilation is a central goal in intensive care, as both premature and delayed extubation
carry avoidable risk. The rapid shallow breathing index (RSBI) is widely used but limited by low specificity, while diaphragm ultrasound
offers a bedside measure of respiratory muscle performance. We compared RSBI, the diaphragm thickening fraction index (DTFI),
and their combination for predicting weaning outcome.
Methods: This single-centre prospective observational study enrolled 157 adults ventilated for at least 24 hours in a mixed medical–
surgical ICU who were ready for their first spontaneous breathing trial (SBT). After tolerating an SBT, RSBI was recorded and the
diaphragm thickening fraction was measured with ultrasound in the zone of apposition. Weaning success was defined as unassisted
breathing sustained for 48 hours. Diagnostic performance was assessed using receiver operating characteristic (ROC) curves.
Results: Weaning failed in 21 patients (13.4%). Age, BMI, duration of ventilation, ICU stay, haemodynamics and gas-exchange
variables did not differ between groups. RSBI was similar in patients who failed and succeeded (69.94 vs 67.35 breaths/min/L; p =
0.369), whereas DTFI was markedly lower in the failure group (24.98% vs 39.02%; p < 0.001). Areas under the curve were 0.423 for
RSBI, 0.750 for DTFI and 0.765 for the combination. At RSBI ≤ 105, sensitivity was 100% but specificity only 5%; at DTFI ≥ 26%,
sensitivity was 83% and specificity 57%. Combining the two did not improve on DTFI alone.
Conclusion: DTFI predicted weaning outcome substantially better than RSBI and performed comparably to the combined index.
Diaphragm ultrasound is a simple, reproducible bedside adjunct that can strengthen the assessment of weaning readiness in critically
ill patients.
References
Vivier E, Mekontso Dessap A, Dimassi S, Vargas F, Lyazidi A, Thille AW, et al. Diaphragm ultrasonography to estimate the work of breathing during noninvasive ventilation. Intensive Care Med. 2012;38(5):796–803.
Boles JM, Bion J, Connors A, Herridge M, Marsh B, Melot C, et al. Weaning from mechanical ventilation. EurRespir J. 2007;29(5):1033–56.
Yang KL, Tobin MJ. A prospective study of indexes predicting the outcome of trials of weaning from mechanical ventilation. N Engl J Med. 1991;324(21):1445–50.
Wait JL, Nahormek PA, Yost WT, Rochester DP. Diaphragmatic thickness–lung volume relationship in vivo. J Appl Physiol. 1989;67(4):1560–8.
Ferrari G, De Filippi G, Elia F, Panero F, Volpicelli G, Aprà F. Diaphragm ultrasound as a new index of discontinuation from mechanical ventilation. Crit Ultrasound J. 2014;6(1):8.
Karthika M, Al Enezi FA, Pillai LV, Arabi YM. Rapid shallow breathing index. Ann Thorac Med. 2016;11(3):167–76.
Goligher EC, Dres M, Fan E, Rubenfeld GD, Scales DC, Herridge MS, et al. Mechanical ventilation-induced diaphragm atrophy strongly impacts clinical outcomes. Am J RespirCrit Care Med. 2018;197(2):204–13.
Spadaro S, Grasso S, Mauri T, Dalla Corte F, Alvisi V, Ragazzi R, et al. Can diaphragmatic ultrasonography performed during the T-tube trial predict weaning failure? The role of the diaphragmatic rapid shallow breathing index.Crit Care. 2016;20(1):305.
Llamas-Álvarez AM, Tenza-Lozano EM, Latour-Pérez J. Diaphragm and lung ultrasound to predict weaning outcome: systematic review and meta-analysis. Chest. 2017;152(6):1140–50.
Pirompanich P, Romsaiyut S. Use of diaphragm thickening fraction combined with rapid shallow breathing index for predicting success of weaning from mechanical ventilator in medical patients. J Intensive Care. 2018;6:6.
Ghiani A, Paderewska J, Sainis A, Crispin A, Walcher S, Neurohr C. Variables predicting weaning outcome in prolonged mechanically ventilated tracheotomized patients: a retrospective study. J Intensive Care. 2020;8:19.
Trivedi V, Chaudhuri D, Jinah R, Piticaru J, Agarwal A, Liu K, et al. The usefulness of the rapid shallow breathing index in predicting successful extubation: a systematic review and meta-analysis. Chest. 2022;161(1):97–111.
Verceles AC, Diaz-Abad M, Geiger-Brown J, Scharf SM. Testing the prognostic value of the rapid shallow breathing index in predicting successful weaning in patients requiring prolonged mechanical ventilation. Heart Lung. 2012;41(6):546–52.
Song J, Qian Z, Zhang H, Wang M, Yu Y, Ye C, et al. Diaphragmatic ultrasonography-based rapid shallow breathing index for predicting weaning outcome during a pressure support ventilation spontaneous breathing trial. BMC Pulm Med. 2022;22:337.
Rittayamai N, Ratchaneewong N, Tanomsina P, Kongla W. Validation of rapid shallow breathing index displayed by the ventilator compared to the standard technique in patients with readiness for weaning. BMC Pulm Med. 2021;21(1):310.
Lin H, Yao M, Qin Z, Fu S, Wang H. Predictive values of ultrasonic diaphragm thickening fraction combined with integrative weaning index in weaning patients with mechanical ventilation: a retrospective study. J Cardiothorac Surg. 2024;19(1):66.
Medrinal C, Combret Y, Hilfiker R, Prieur G, Aroichane N, Gravier FE, et al. ICU outcomes can be predicted by noninvasive muscle evaluation: a meta-analysis. EurRespir J. 2020;56(4):1902482.
Le Neindre A, Philippart F, Luperto M, Wormser J, Morel-Sapene J, Aho SL, et al. Diagnostic accuracy of diaphragm ultrasound to predict weaning outcome: a systematic review and meta-analysis. Int J Nurs Stud. 2021;117:103890.
Haaksma ME, Smit JM, Boussuges A, Demoule A, Dres M, Ferrari G, et al. EXpert consensus On Diaphragm UltraSonography in the critically ill (EXODUS): a Delphi consensus statement on the measurement of diaphragm ultrasound-derived parameters. Crit Care. 2022;26(1):99.
Esteban A, Frutos F, Tobin MJ, Alía I, Solsona JF, Valverdú I, et al. A comparison of four methods of weaning patients from mechanical ventilation. N Engl J Med. 1995;332(6):345–50.
Downloads
Published
How to Cite
Issue
Section
License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
