Narrative review of practical aspects of aerosol delivery via high-flow nasal cannula

High-flow nasal cannula and in-line aerosolised bronchodilator delivery during severe exacerbation of asthma in adults: a feasibility observational study

BACKGROUND

Asthma is a common chronic respiratory disease affecting 1-29% of the population in different countries. Exacerbations represent a change in symptoms and lung function from the patient's usual condition that requires emergency department (ED) admission. Recently, the use of a High-Flow Nasal Cannula (HFNC) plus an in-line vibrating mesh nebulizer (VMN) for aerosol drug delivery has been advocated in clinical practice. Thus, this pilot observational study aims to investigate the feasibility of HFNC treatment with VMN for in-line bronchodilator delivery in patients with severe asthma.

METHODS

This study was conducted from May 2022 to May 2023. Subjects ≥18 years old with a previous diagnosis of asthma who were admitted to the ED during severe exacerbation were included. The primary endpoint was the change in peak expiratory flow ratio (PEFR) after 2-h of treatment with bronchodilator delivered by HFNC with in-line VMN. Additional outcomes were changes in forced expiratory volume in 1 s (FEV1) and clinical variables before treatment.

RESULTS

30 patients, mean age of 43 (SD ± 16) years, mostly female (67%) were studied. A significant change in PEFR (147 ± 31 L/m vs. 220 ± 38 L/m; p < 0.001) was observed after treatment with HFNC and in-line VMN with significant improvement in clinical variables. And no subjects required invasive mechanical ventilation (IMV) during the study.

CONCLUSIONS

HFNC treatment with in-line VMN for bronchodilator delivery appears feasible and safe for patients with severe asthma exacerbation. These preliminary promising results should be confirmed with appropriately large-designed studies.

Dos and don'ts to optimize transnasal aerosol drug delivery in clinical practice

INTRODUCTION

Transnasal aerosol drug delivery has become widely accepted for treating acutely ill infants, children, and adults. More recently aerosol administration to wider populations receiving high and low-flow nasal oxygen has become common practice.

AREAS COVERED

Skepticism of insufficient aerosol delivery to the lungs has been tempered by multiple in vitro explorations of variables to optimize delivery efficiency. Additionally, clinical studies demonstrated comparable clinical responses to orally inhaled aerosols. This paper provides essential clinical guidance on how to improve transnasal aerosol delivery based on device-, settings-, and drug-related optimization to serve as a resource for educational initiatives and quality enhancement endeavors at healthcare institutions.

EXPERT OPINION

Transnasal aerosol delivery is proliferating worldwide, but indiscriminate use of excessive-high flows, poor selection and placement of aerosol devices and circuits can greatly reduce aerosol delivery and efficacy, potentially compromising treatment to acute and critically ill patients. Attention to these details can improve inhaled dose by an order of magnitude, making the difference between effective treatment and the progression to more invasive ventilatory support, with greater inherent risk and cost. These revelations have prompted specific recommendations for optimal delivery, driving advancements in aerosol generators, formulations, and future device designs to administer aerosols and maximize treatment effectiveness.

2022 Year in Review: Pediatric Asthma

Asthma is the most common chronic disease in children. Asthma is a heterogeneous disease characterized by variable, reversible airway obstruction and hyper-responsive airways. There is a high economic burden due to a child having poorly controlled asthma with one or more asthma exacerbations resulting in an emergency department visit or hospitalization in a year. Publications on diagnosis, treatment, and management of pediatric asthma are ongoing with over 2,549 papers published from January-November 2022. The intent of this paper is to summarize 8 key topics that have prompted discussions with local, regional, and national asthma experts due to a shift in clinical practice or lessons learned from the recent pandemic that may have future application.

Helmet CPAP bundle: A narrative review of practical aspects and nursing interventions to improve patient's comfort

BACKGROUND

The application of Continuous Positive Airway Pressure (CPAP) with a helmet is increasing around the world, both inside and outside of the intensive care unit. Current published literature focus's on indications, contraindications and efficiency of Helmet CPAP in differing clinical scenarios. Few reports, summarising the available knowledge concerning technical characteristics and nursing interventions to improve patient's comfort, are available.

AIM

To identify the crucial technical aspects in managing patients undergoing Helmet-CPAP, and what nursing interventions may increase comfort.

METHODS

A narrative literature review of primary research published 2002 onwards. The search strategy comprised an electronic search of three bibliographic databases (Pubmed, Embase, CINAHL).

RESULTS

Twenty-three studies met the inclusion criteria and were included in the review. Research primarily originated from Italy. Nine key themes emerged from the review: gas flow management, noise reduction, impact of gas flow and HME filters on delivered FiO₂, filtration of exhaled gas / environmental protection, PEEP monitoring, airway pressure monitoring, active humidification of gas flow, helmet fixation and tips to implement awake prone position during Helmet-CPAP.

CONCLUSIONS

A Helmet-CPAP check-list has been made of nine key interventions based on the available evidence regarding system set up, monitoring and management. Implementation of this check-list may help nurses and physicians to increase the comfort of patients treated with Helmet CPAP and enhance their compliance with long-term treatment.

Inhaled Milrinone via HFNC as a Postextubation Cardiopulmonary Elixir: Case Series and Review of Literature

Pulmonary hypertension (PH) often complicates perioperative course following pediatric cardiac surgery, often presenting unique challenges to the attending cardiac anesthesiologist. Apart from difficult weaning from cardiopulmonary bypass, PH can often compound weaning from mechanical ventilation in this postoperative subset. From pathophysiological standpoint, the former can be attributed to concurrent detrimental cardiopulmonary consequences of PH as a multisystemic syndrome. Therefore, with an objective to address the affected systems, that is, cardiac and pulmonary simultaneously, we report combined use of inhaled milrinone (a pulmonary vasodilator) through high-frequency nasal cannula (oxygen reservoir and continuous positive airway pressure delivery device), purported to complement each other's mechanism of action in the management of PH, thereby hastening postoperative recovery. This article additionally presents a nuanced perspective on the advantages of combining the aforementioned therapies and hence proposing the same as a possible “postoperative cardiopulmonary elixir.”

Inhaled Milrinone via HFNC as a Postextubation Cardiopulmonary Elixir: Case Series and Review of Literature

Pulmonary hypertension (PH) often complicates perioperative course following pediatric cardiac surgery, often presenting unique challenges to the attending cardiac anesthesiologist. Apart from difficult weaning from cardiopulmonary bypass, PH can often compound weaning from mechanical ventilation in this postoperative subset. From pathophysiological standpoint, the former can be attributed to concurrent detrimental cardiopulmonary consequences of PH as a multisystemic syndrome. Therefore, with an objective to address the affected systems, that is, cardiac and pulmonary simultaneously, we report combined use of inhaled milrinone (a pulmonary vasodilator) through high-frequency nasal cannula (oxygen reservoir and continuous positive airway pressure delivery device), purported to complement each other's mechanism of action in the management of PH, thereby hastening postoperative recovery. The article additionally presents a nuanced perspective on the advantages of combining the aforementioned therapies and hence proposing the same as a possible “postoperative cardiopulmonary elixir.”

Aerosolized drug delivery in awake and anesthetized children to treat bronchospasm

Bronchospasm is a common respiratory adverse event in pediatric anesthesia. First-line treatment commonly includes inhaled salbutamol. This review focuses on the current best practice to deliver aerosolized medications to awake as well as anesthetized pediatric patients and discusses the advantages and disadvantages of various administration techniques. Additionally, we detail the differences between various airway devices used in anesthesia. We highlight the unmet need for innovation of orally inhaled drug products to deliver aerosolized medications during pediatric respiratory critical events such as bronchospasm. It is therefore important that clinicians remain up to date with the best clinical practice for aerosolized drug delivery in order to prevent and efficiently treat pediatric patients experiencing life-threatening respiratory emergencies.