The clinical advantage of nasal high-flow in respiratory management during procedural sedation: A scoping review on the application of nasal high-flow during dental procedures with sedation.

Structured summary: Rationale: Nasal high-flow (NHF), a new method for respiratory management during procedural sedation, has greater advantages than conventional nasal therapy with oxygen. However, its clinical relevance for patients undergoing oral maxillofacial surgery and/or dental treatment remains uncertain and controversial, due to a paucity of studies. This scoping review compared and evaluated NHF and conventional nasal therapy with oxygen in patients undergoing oral maxillofacial surgery and/or dental treatment. Materials and methods: A literature search of two public electronic databases was conducted, and English writing randomized controlled trials (RCTs) of nasal high flow during dental procedure with sedation reviewed. The primary and secondary outcomes of interest were the incidence of hypoxemia and hypercapnia during sedation and the need for intervention to relieve upper airway obstruction, respectively. Results: The search strategy yielded 7 studies, of which three RCTs met our eligibility criteria, with a total of 78 patients. Compared with conventional nasal therapy with oxygen, NHF significantly reduced the incidence of hypoxemia and hypercapnia during procedural sedation. Conclusion: NHF can maintain oxygenation and possibly prevent hypercapnia in patients undergoing dental treatment. Additional RCTs are needed to clarify and confirm these findings.

Efficacy of nasal high flow therapy on the coordination between breathing and swallowing of saliva during daytime nap in chronic obstructive pulmonary disease patients: A single center, randomized crossover controlled study.

BACKGROUND: There are some clinical reports on dysphagia in patients with chronic obstructive pulmonary disease (COPD); however, its pathophysiology remains largely unknown.Changes in respiratory function occur in patients with COPD causing a decrease in tidal volume and an increase in respiratory rate (tachypnea). In addition, it leads to lack of coordination between respiration and swallowing.A new treatment called nasal high flow (NHF) has been introduced for patients with COPD, replacing the traditional non-invasive ventilation (NIV) procedure. The NHF therapy involves inhalation of high flow of humidified air, which reduces respiratory effort in patients with COPD. Furthermore, NHF therapy facilitates swallowing of saliva even during respiratory management. A recent clinical study reported that high-flow nasal cannula oxygen therapy for 6 weeks improved the health-related quality of life and reduced hypercapnia in patients with stable COPD. Taken together, NHF therapy is gaining attention in the clinical management of patients with COPD.Therefore, in this study, we aim to examine the efficacy of NHF therapy on the coordination between breathing and swallowing of saliva during daytime nap in patients with COPD. METHODS/DESIGN: This open-label, investigator-initiated, single center study will evaluate the efficacy of NHF therapy on the coordination between breathing and swallowing of saliva during the daytime nap in COPD patients with forced expiratory volume in 1 second (FEV1%) of <70% during treatment at the Nagasaki University Hospital Respiratory Rehabilitation Center. Evaluations will be performed during the 90 to 180 minute "daytime nap" in the measurement room of the hospital. The primary endpoint will be the rate of appearance of the expiratory phase after swallowing of saliva and the frequency of swallowing during the measurement period. DISCUSSION: The purpose of this study is to obtain evidence regarding the utility of NHF as a potential therapeutic device for COPD patients to prevent aspiration of saliva during the sleep stage of daytime nap. The utility will be assessed by comparing the decrease in incidence rates of the expiratory phase after swallowing of saliva in the NHF device group and the control group, wherein this device was not used.

Study on prevention of hypercapnia by nasal high flow in patients undergoing endoscopic retrograde cholangiopancreatography during intravenous anesthesia.

BACKGROUND: For relatively invasive upper gastrointestinal endoscopy procedures, such as an endoscopic retrograde cholangiopancreatography (ERCP), and also lower gastrointestinal endoscopy procedures, intravenous anesthesia is routinely used to reduce patient anxiety. However, with the use of intravenous anesthesia, even at mild to moderate depth of anesthesia, there is always a risk of upper airway obstruction due to a relaxation of the upper airway muscles.With the advent of nasal high flow (NHF) devices that allow humidified high flow air through the nasal cavity, can be used as a respiratory management method in the context of anesthesia. AIRVO is commonly used for patients with obstructive sleep apnea and other respiratory disorders. This device uses a mild positive pressure load (several cmH2O) that improves carbon dioxide (CO2) washout and reduces rebreathing to improve respiratory function and therefore is widely used to prevent hypoxemia and hypercapnia.This study aims to maintain upper airway patency by applying NHF with air (AIRVO) as a respiratory management method during intravenous anesthesia for patients undergoing an ERCP. In addition, this study investigates whether the use of an NHF device in this context can prevent intraoperative hypercapnia and hypoxemia. METHODS/DESIGN: This study design employed 2 groups of subjects. Both received intravenous anesthesia while undergoing an ERCP, and 1 group also used a concurrent nasal cannula NHF device. Here we examine if the use of an NHF device during intravenous anesthesia can prevent hypoxemia and hypercapnia, which could translate to improved anesthesia management.Efficacy endpoints were assessed using a transcutaneous CO2 monitor (TCM). This device measured the changes in CO2 concentration during treatment. Transcutaneous CO2 (PtcCO2) concentrations of 60 mm Hg or more (PaCO2 > 55 mm Hg) were considered marked hypercapnia. PtcCO2 concentrations of 50 to 60 mm Hg or more (equivalent to PaCO2 > 45 mm Hg) were considered moderate hypercapnia.Furthermore, the incidence of hypoxemia with a transcutaneous oxygen saturation value of 90% or less, and whether the use of NHF was effective in preventing this adverse clinical event were evaluated. DISCUSSION: The purpose of this study was to obtain evidence for the utility of NHF as a potential therapeutic device for patients undergoing an ERCP under sedation, assessed by determining if the incidence rates of hypercapnia and hypoxemia decreased in the NHF device group, compared to the control group that did not use this device. TRIAL REGISTRATION: The study was registered in the jRCTs 072190021.URL https://jrct.niph.go.jp/en-latest-detail/jRCTs072190021.

Study on prevention of hypercapnia by Nasal High Flow in patients with endoscopic submucosal dissection during intravenous anesthesia.

BACKGROUND: For relatively invasive upper gastrointestinal endoscopy procedures, such as an endoscopic submucosal dissection (ESD), intravenous anesthesia is routinely used to reduce patient anxiety. However, with the use of intravenous sedation, even at mild to moderate depth of anesthesia, there is always a risk of upper airway obstruction due to a relaxation of the upper airway muscles.With the advent of Nasal High Flow (NHF) devices that allow humidified high flow air through the nasal cavity, can be used as a respiratory management method in the context of anesthesia. AIRVO is commonly used for patients with obstructive sleep apnea and other respiratory disorders. This device uses a mild positive pressure load (several cmH2O) that improves carbon dioxide (CO2) washout and reduces rebreathing to improve respiratory function and therefore is widely used to prevent hypoxemia and hypercapnia.This study aims to maintain upper airway patency by applying NHF with air (AIRVO) as a respiratory management method during intravenous anesthesia for patients undergoing an ESD. In addition, this study investigates whether the use of an NHF device in this context can prevent intraoperative hypercapnia and hypoxemia. METHODS/DESIGN: This study design employed 2 groups of subjects. Both received intravenous anesthesia while undergoing an ESD, and 1 group also used a concurrent nasal cannula NHF device. Here we examine if the use of an NHF device during intravenous anesthesia can prevent hypoxemia and hypercapnia, which could translate to improved anesthesia management.Efficacy endpoints were assessed using a transcutaneous CO2 monitor. This device measured the changes in CO2 concentration during treatment. Transcutaneous CO2 (PtcCO2) concentrations of 60 mmHg or more (PaCO2 > 55 mmHg) were considered marked hypercapnia. PtcCO2 concentrations of 50 to 60 mmHg or more (equivalent to PaCO2 > 45 mmHg) were considered moderate hypercapnia.Furthermore, the incidence of hypoxemia with a transcutaneous oxygen saturation value of 90% or less, and whether the use of NHF was effective in preventing this adverse clinical event were evaluated. DISCUSSION: The purpose of this study was to obtain evidence for the utility of NHF as a potential therapeutic device for patients undergoing an ESD under anesthesia, assessed by determining if the incidence rates of hypercapnia and hypoxemia decreased in the NHF device group, compared to the control group that did not use of this device. TRIAL REGISTRATION: The study was registered the jRCTs 072190022.URL https://jrct.niph.go.jp/en-latest-detail/jRCTs072190022.

Nasal high flow improves ventilation during propofol sedation: A randomized cross-over study in healthy volunteers.

OBJECTIVE: Hypoventilation and carbon dioxide (CO2) retention are common during sedation. The current study investigated the ventilation responses to nasal high flow (NHF) during sedation with propofol. METHODS: NHF of 30 L/min and 60 L/min with room air was applied during wakefulness and sedation in 10 male volunteers. Ventilation was monitored by respiratory inductance plethysmography, transcutaneous partial pressure of CO2 (TcCO2), and SpO2. RESULTS: During sedation, NHF of 30 L/min and 60 L/min reduced the TcCO2 by 2.9 ± 2.7 mmHg (p = 0.025) and by 3.6 ± 3.4 mmHg (p = 0.024) without affecting SpO2 and reduced the mean respiratory rate by 3 ± 3 breaths/min (p = 0.011) and by 4 ± 3 breaths/min (p = 0.003), respectively. CONCLUSION: During sedation with propofol, NHF without supplemental oxygen attenuated CO2 retention and reduced the respiratory rate. The findings show that NHF can improve ventilation during sedation, which may reduce the risk of complications related to hypoventilation.