Proposed Topic (Most preferred): :
Clinical Safety and Quality Service II (Projects aiming to enhance clinical safety and outcomes, clinical governance / risk management)
Proposed Topic (Second preferred): :
Clinical Safety and Quality Service III (Projects aiming at quality service to patients and their carers)
Authors (including presenting author) :
Liu KN(1)(3), Tai CE(2), Dr. Cheung CF (2), Dr. Wong TL (2), Dr. Tang SW (2), Choi WY (3), Fok MY (3), Lung WY(3)
Affiliation :
(1) NTWC Respiratory Nurse Service, (2)Pok Oi Hospital Respiratory Team, (3) Pok Oi Hospital NIV Team
Introduction :
Background
High Flow Oxygen Therapy (HFOT) has emerged as an alternative to oxygenation support in clinical areas during recent decades. In the COVID-19 pandemic, the HFOT has shown its efficacy in managing Acute Respiratory Distress Syndrome (ARDS) in COVID-19 patients. An increasing trend is observed from worldwide data for the application of the HFOT as the management in other diagnoses which may complicated with acute respiratory failure, for example, congestive heart failure, severe pneumonia and fluid overload, etc.
Before the COVID-19 pandemic, the use of HFOT was only in the pilot stage due to limited experience and device availability. The pandemic has expedited the clinical implementation of HFOT along with sufficient devices available at the time. The confidence is built on the clinical use of HFOT as the pandemic progresses. Besides managing acute respiratory failure at the frontline, we have also investigated the role of HFOT as a preventive measure and management of hypoxemia during bronchoscopy procedures.
Conventional Oxygen Therapy (COT) and non-invasive ventilation (NIV) have been considered as the limited options for oxygenation support during the peri- and post-bronchoscopy situation. Studies have proven the advent of the HFOT offered an option for the physician to offer effective hypoxemia management with optimal outcomes.
Objectives :
Advantage of HFOT
High-flow oxygen device equipped with a specialized system to provide a steady fraction of inspired oxygen (FiO2) under a preset flow (up to 60L/min), with heated and moisturized respiratory mixture via the interface. The advantages manifest as:
1. Flush out dead space air in the bronchus and pharyngeal space;
2. Generate a positive end-expiratory pressure to support the lower respiratory tract and prevent alveoli collapse;
3. Enhance secretion clearance after the procedure;
4. Improve patient tolerance with the “nasal cannula-like” interface compared to the NIV full-face mask.
Hypoxemia has been one of the potential complications during peri- and post-bronchoscopic procedures. It is reported that patients with pulmonary complications may occasionally deteriorate and require invasive mechanical ventilation (IMV). In a study that observed stable patients who did not require oxygen support before bronchoscopy, 24% of them observed desaturation in peri-procedure and 14% of them required oxygen support. Some studies have found a high chance (up to 60%) of desaturation even with COT support, despite COT being the common strategy to manage the situation. Multiple studies have shown the application of HFOT in bronchoscopy could reduce hypoxemic events and improve the lowest SpO2 compared to COT. In post-bronchoscopy situations, the enhancement in secretion clearance also reduces the risk of further step-up to NIV or IMV. These benefits of HFOT played an important role in reducing patient suffering from avoidable complications and eventually alleviating the potential after-care to the frontline.
Methodology :
Implementation
HFOT were dispatched to various hospitals in Hong Kong in early 2021 as an alternative option in ventilatory support for COVID-19 patients. This posed a great challenge to the frontline to handle a new device under the critical pandemic situation. We have put great effort into training to transfer knowledge and experience during the early phase, to ensure confidence in the clinical management and nursing care of the HFOT.
From 2021 to 2023, it is recorded annually approximately 450-500 patients undergo bronchoscopy at Pok Oi Hospital (POH). The first implementation of HFOT during bronchoscopy in POH was recorded in March 2021. Around 6 % of bronchoscopy procedures involved HFOT in the first year (2021). As the care experience consolidated with increased clinical applications, the use of HFOT has reached 36% among all bronchoscopies performed in 2022 and up to 51% by the end of 2023.
The HFOT is expected to improve ventilatory support during peri- and post-bronchoscopy. It is targeted to wean off HFOT as soon as (e.g. same day of procedure performed) patient tolerates. It is recorded that 94% of patients offered HFOT have successfully weaned off the device in the same day after bronchoscopy in both 2022 and 2023.
Discussion
The remaining 6% of patients (10 in 2022 and 16 in 2023 respectively) required an average of 3 days of HFOT support after the procedure, ranging from a minimum 1 day to a maximum of 12 days. Among these patients who required extended HFOT support, 40% of them stepped up to non-invasive ventilation (NIV) in 2022, while 13% of patients were recorded in 2023. The improved clinical experience and nursing care on HFOT may contribute to better outcomes. Patients receiving HFOT should be monitored closely for their response to the treatment and may escalate to NIV or intubation if their condition deteriorates. The average HFOT day before NIV changed from 5 days in 2022 to 1 day in 2023 among the group of high-risk patients.
Result & Outcome :
Conclusion
High Flow Oxygen Therapy is a developing treatment strategy in various situations. It is increasingly adopted as an option of ventilatory support before stepping up to NIV or IMV, from acute scenario to peri- and post-procedure support. The observation of this report is limited to the dependence of clinical judgment for the application of HFOT during the recorded period, and variables might contribute effect on the outcome, for example, the progress of the pandemic. A structured guideline on case screening might benefit high-risk patients undergoing bronchoscopy. Moreover, standardized training on HFOT for nursing staff could ensure the quality of care and monitoring of those patients.
