Predictors of HFNC Failure in Patients With AHRF Using Diaphragm Ultrasound

Queen Mary Hospital, Hong Kong30 enrolled

Overview

Ultrasound of the diaphragm is an easily reproducible bedside tool that provides a non-invasive measurement of inspiratory muscle function and respiratory efficiency. The diaphragmatic thickness correlates with the strength and muscle shortening and is reflective of its contribution to the respiratory workload. Diaphragm thickening fraction (DTF) has been shown to be predictive of extubation failure in ventilated patients. However, whether measurements of DTF are predictive of high flow nasal cannula (HFNC) outcomes in patients with acute hypoxemic respiratory failure (AHRF) remains unknown. The objective of this study is to identify predictors of HFNC failure by diaphragm ultrasound and to compare its performance with the well-established ROX index.

Study Type

OBSERVATIONAL

Enrollment

Conditions

Acute Hypoxemic Respiratory Failure

Interventions

Diaphragm UltrasoundDIAGNOSTIC_TEST

Diaphragm ultrasound to assess respiratory muscle function and respiratory efficiency

Medical Language ↔ Plain English

Inclusion Criteria: * Age ≧ 18; AND * Acute hypoxemic respiratory failure (AHRF), defined by respiratory rate of greater than 25 breaths per minute and a ratio of the PaO2 to the fraction of inspired oxygen (PaO2 / FiO2) of less than 300, and use of accessory muscles of respiration or paradoxical abdominal motion; AND * Required ventilatory support with high-flow nasal cannula (HFNC) Exclusion Criteria: * Patients suffering from hypercapnic respiratory failure; OR * AHRF secondary to conditions that are indicated for non-invasive ventilation (NIV) (e.g. acute exacerbation of COPD, cardiogenic pulmonary edema); OR * Use of NIV or invasive mechanical ventilation (IMV) prior to HFNC initiation; OR * Patients with imminent need for endotracheal intubation and invasive mechanical ventilation (IMV); OR * Patients with known or suspected diaphragm paralysis; OR * Pregnancy; OR * Patients with abdominal compartment syndrome; OR * Use of HFNC for more than 12 hours prior to ICU admission; OR * Patients with suboptimal diaphragm ultrasound image quality for data processing; OR

Outcomes

Primary Outcomes

High flow nasal cannula (HFNC) therapeutic failure

Predictive value of diaphragm ultrasound in detecting high flow nasal cannula (HFNC)therapeutic failure in patients with acute hypoxemic respiratory failure (AHRF)

Time frame: From the start of recruitment into study (i.e. start of HFNC use), till the date of study endpoint (i.e., step up to non-invasive ventilation, intubation, death on HFNC, or weaned off HFNC, whichever came first), assessed up to 4 weeks.