The role of diaphragmatic thickness measurement in weaning prediction and its comparison with rapid shallow breathing index: a single-center experience

Abstract

Background: Acute respiratory failure (ARF) is commonly managed with invasive mechanical ventilation (IMV). The majority of the time that a patient spends on IMV is in the process of weaning. Prediction of the weaning outcome is of paramount importance, as untimely/delayed extubation is associated with a high risk of mortality. Diaphragmatic ultrasonography is a promising tool in the intensive care unit, and its utility in predicting the success of weaning remains understudied. Methods: In this prospective-observational study, we recruited 54 ARF patients on IMV, along with 50 healthy controls. During a spontaneous breathing trial, all subjects underwent diaphragmatic ultrasonography along with a rapid shallow breathing index (RSBI) assessment. Results: The mean age was 41.8±17.0 and 37.6±10.5 years among the cases and control group, respectively. Demographic variables were broadly similar in the two groups. The most common cause of ARF was obstructive airway disease. The average duration of IMV was 5.41±2.81 days. Out of 54 subjects, 45 were successfully weaned, while nine patients failed weaning. Age, body mass index, and severity of disease were similar in the successful and failed weaning patients. The sensitivity in predicting successful weaning of percent change in diaphragmatic thickness (Δtdi%) >29.71% was high (93.33%), while specificity was 66.67%. The sensitivity and specificity of mean diaphragmatic thickness (tdi) end-expiratory >0.178 cm was 60.00% and 77.78%, respectively. RSBI at 1 minute of <93.75 had an equally high sensitivity (93.33%) but a lower specificity (22.22%). Similar results were also found for RSBI measured at 5 minutes. Conclusions: During the weaning assessment, the purpose is to minimize both premature as well as delayed extubation. We found that diaphragmatic ultrasonography, in particular Δtdi%, is better than RSBI in predicting weaning outcomes.

Accuracy of respiratory muscle assessments to predict weaning outcomes: a systematic review and comparative meta-analysis

“…Studies reporting on accuracy to predict weaning outcomes and included in the meta-analysis involved assessment of PImax ( n = 18 studies) [ 24 – 41 ], diaphragm ultrasound assessments with diaphragm excursion (DE, n = 53 studies) [ 6 , 26 , 30 , 31 , 35 , 37 , 39 – 85 ], diaphragm thickening fraction (DTF, n = 48 studies) [ 38 , 40 , 43 – 56 , 62 , 65 – 67 , 69 , 71 – 73 , 75 – 77 , 79 , 81 – 84 , 86 – 101 ] and end-expiratory (Tdi ee , n = 11 studies) [ 45 , 48 , 53 – 55 , 66 , 73 , 89 , 90 , 99 , 100 ], end-inspiratory diaphragm thickness (Tdi ei , n = 8 studies) [ 48 , 53 – 55 , 66 , 73 , 89 , 100 ] and P0.1 ( n = 15 studies) [ 25 , 27 , 29 , 36 , 73 , 81 , 102 – 110 ] (See Additional file 1 : Table S3 for study characteristics). Different weaning outcome definitions were used across studies (Additional file 1 : Table S3).…”

“…At least 4 direct comparative studies reporting on accuracy to predict weaning success were found for the following pairs of assessments: DE versus PImax ( n = 8 studies) [ 30 , 31 , 35 , 37 , 39 – 41 ], DE versus DTF ( n = 28 studies) [ 40 , 43 – 45 , 47 – 52 , 54 , 56 , 62 , 65 – 67 , 69 , 71 – 73 , 75 , 77 , 79 , 81 – 84 , 117 ], DE versus Tdi ee ( n = 5 studies) [ 45 , 48 , 54 , 66 , 73 ], DE versus Tdi ei ( n = 4 studies) [ 48 , 54 , 66 , 73 ], DTF versus Tdi ee ( n = 11 studies) [ 45 , 48 , 53 – 55 , 66 , 73 , 89 , 90 , 99 , 100 ], DTF versus Tdi ei ( n = 8 studies) [ 48 , 54 , 55 , 66 , 73 , 89 , 100 ] and P0.1 versus PImax ( n = 4 studies) [ 25 , 27 , 29 , 36 ]. The SROC curves estimated based on direct comparative studies are presented in Additional file 1 : Fig.…”

Ultrasonography to Access Diaphragm Dysfunction and Predict the Success of Mechanical Ventilation Weaning in Critical Care

“…One study included patients with complicated weaning (who had failed previous attempts of SBT) 3 and one study included patients at high risk of extubation failure 42 . Some studies focused exclusively on patients with chronic obstructive pulmonary disease (COPD) 5 or COVID‐19 41 or patients whose intubation was due to respiratory causes 28,29,36,39 . This aspect could compromise the applicability of the results due to patient selection.…”

“…Diaphragmatic dysfunction was assessed by DE in six studies, DTF in five and both in nine studies. Seven studies compared diaphragmatic US with other methods that have been previously used to predict successful extubation in the ICU: rapid shallow breathing index (RSBI) 33,34,36,37 and Lung US score 11,34,37 in four and three studies, respectively.…”

“…42 Some studies focused exclusively on patients with chronic obstructive pulmonary disease (COPD) 5 or COVID-19 41 or patients whose intubation was due to respiratory causes. 28,29,36,39 This aspect could compromise the applicability of the results due to patient selection. Exclusion criteria mostly included conditions affecting diaphragm function or assessment.…”