Identifying Subjects at Risk for Diaphragm Atrophy During Mechanical Ventilation Using Routinely Available Clinical Data

Abstract

BACKGROUND: Diaphragmatic respiratory effort during mechanical ventilation is an important determinant of patient outcome, but direct measurement of diaphragmatic contractility requires specialized instrumentation and technical expertise. We sought to determine whether routinely collected clinical variables can predict diaphragmatic contractility and stratify the risk of diaphragm atrophy. METHODS: We conducted a secondary analysis of a prospective cohort study on diaphragm ultrasound in mechanically ventilated subjects. Clinical variables, such as breathing frequency, ventilator settings, and blood gases, were recorded longitudinally. Machine learning techniques were used to identify variables predicting diaphragm contractility and stratifying the risk of diaphragm atrophy (> 10% decrease in thickness from baseline). Performance of the variables was evaluated in mixed-effects logistic regression and random-effects tree models using the area under the receiver operating characteristic curve. RESULTS: Measurements were available for 761 study days in 191 subjects, of whom 73 (38%) developed diaphragm atrophy. No routinely collected clinical variable, alone or in combination, could accurately predict either diaphragm contractility or the development of diaphragm atrophy (model area under the receiver operating characteristic curve 0.63-0.75). The risk of diaphragm atrophy was not significantly different according to the presence or absence of patient-triggered breaths (38.3% vs 38.6%; odds ratio 1.01, 95% CI 0.05-2.03). Diaphragm thickening fraction < 15% during either of the first 2 d of the study was associated with a higher risk of atrophy (44.6% vs 26.1%; odds ratio 2.28, 95% CI 1.05-4.95). CONCLUSIONS: Diaphragmatic contractility and the risk of diaphragm atrophy could not be reliably determined from routinely collected clinical variables and ventilator settings. A single measurement of diaphragm thickening fraction measured within 48 h of initiating mechanical ventilation can be used to stratify the risk of diaphragm atrophy during mechanical ventilation.

Diaphragm Ultrasound in Critically Ill Patients on Mechanical Ventilation—Evolving Concepts

“…Also, as already demonstrated in previous studies, diaphragmatic atrophy due to disuse can occur even in assisted ventilation [ 37 , 67 , 77 ] indicating that simply triggering the ventilator is not enough to prevent diaphragm atrophy. In addition, clinical variables and ventilator settings are not able to detect contractility and risk of diaphragm atrophy.…”

“…In addition, clinical variables and ventilator settings are not able to detect contractility and risk of diaphragm atrophy. [ 67 ].…”

COVID-19 related to sarcopenia: Current perspectives on etiology, clinical implications, and nutritional rehabilitation

“…In this follow-up, disease progression is reflected by excessive drug administration, multiple organ failure, admission to the intensive care unit (ICU), increased need for mechanical ventilation, and mortality 5 . In addition, prolonged mechanical ventilation can lead to diaphragm atrophy, resulting in a decrease in muscle thickness, accompanied by below-normal respiratory effort 19 . However, because of the pulmonary complications caused by COVID-19, it is often necessary to use mechanical ventilation to avoid even worse prognoses [19][20][21][22] .…”

“…In addition, prolonged mechanical ventilation can lead to diaphragm atrophy, resulting in a decrease in muscle thickness, accompanied by below-normal respiratory effort 19 . However, because of the pulmonary complications caused by COVID-19, it is often necessary to use mechanical ventilation to avoid even worse prognoses [19][20][21][22] . Since the beginning of the SARS-CoV-2 pandemic, other common manifestations have been detected among those affected, such as fever, dry cough, dyspnea, generalized myalgia, migraine, tonsillitis, viral pneumonia, worsened inflammatory response and pathophysiological changes, and reduction in skeletal muscle mass 14,20 .…”

What Can We Learn From Monitoring Diaphragm Activity in Infants?*

“…Yet, clinicians caring for mechanically ventilated patients may not be aware of the presence and magnitude of the respiratory muscle pump action because direct assessment is required. Surrogate markers such as respiratory rate have proven to be very unreliable measures of respiratory drive and effort (1, 2). If respiratory effort is to be known, it must be measured.…”