Fisher & Paykel Healthcare Corporation Limited (FPH) is a manufacturer, designer and marketer of products and systems for use in respiratory care, acute care, and the treatment of obstructive sleep apnea. Based in New Zealand, their products and systems are sold in around 120 countries worldwide. FPH is primarily an exporting company, with just 1 percent of revenue coming from New Zealand sales.
Purpose:Nasal high flow (NHF) is increasingly used in COPD patients with chronic respiratory failure. An asymmetrical cannula interface (AI) may enhance these benefits by combining increased airway pressure with reduced rebreathing from anatomical dead space. The aim of this study was to compare the effects of NHF using an AI versus a conventional symmetrical interface (SI) on tidal volume (Vt), respiratory rate (RR), minute ventilation (MV), gas exchange, and neuro-respiratory drive (NRD). Methods:Following a 15-minute baseline period, COPD patients recovering from acute exacerbation underwent two randomized 45-minute sessions of NHF therapy using either the AI or SI. All sessions were conducted during daytime in a semi-recumbent position. Ventilation was recorded using calibrated respiratory inductance plethysmography, and transcutaneous CO2 (TcCO2) and oxygen saturation (SpO2) were continuously monitored. In addition, intercostal surface electromyography (sEMG) of the parasternal muscles was performed to assess NRD. Results:In a group of 18 patients NHF significantly reduced RR and TcCO2, regardless of the interface used. AI significantly reduced MV compared with both baseline and SI (p = 0.048), while SpO2 increased. sEMG activity increased compared with baseline without a corresponding rise in tidal volume; however, no difference was observed between the two interfaces. Conclusion:NHF reduced RR by increasing both expiratory and inspiratory times without altering the duty cycle. The lower MV during NHF with AI, accompanied by higher SpO2, may indicate improved gas exchange efficiency. The use of AI could enhance the respiratory support effects of NHF in patients with advanced COPD.
Background: Aerosol delivery during nasal high-flow (NHF) therapy occurs within a heated and humidified environment where formulation composition, NHF rate, and Next Generation Impactor (NGI)/system temperature may jointly influence aerosol behavior. However, their combined effects following NHF-conditioned transport remain incompletely characterized. Methods: A balanced 4 × 2 × 2 full-factorial design evaluated NGI/system temperature (5, 21, 37, and 40 °C), formulation (isotonic and 3% hypertonic salbutamol formulations), and NHF rate (30 and 50 L·min−1). Aerosols generated using a vibrating mesh nebulizer integrated within an NHF system were transported through an adult nasal replica coupled to an NGI. Particle-size, fine-particle, delivery-efficiency, and regional-deposition metrics were analyzed using factorial ANOVA. Results: NHF rate exerted the greatest influence on downstream aerosol delivery, with increasing NHF rate reducing delivery efficiency, Fine Particle Dose (FPD), and NGI deposition while increasing NHF circuit retention. Significant Temperature × Formulation × Flow interactions were observed for MMAD (p = 0.0055), D16 (p < 0.0001), GSD (p = 0.0009), Fine Particle Fraction (FPF) (p = 0.0042), and dose-normalized FPD (p = 0.0149). The hypertonic formulation exhibited greater thermal sensitivity across several particle metrics. Although increasing NGI/system temperature generally reduced MMAD, D16, and D84, similar reductions in MMAD frequently produced markedly different responses in FPF, FPD, delivery efficiency, and regional deposition. All aerosols remained within ranges commonly associated with pulmonary deposition. Conclusions: Aerosol characteristics during NHF are governed by interacting effects of flow, formulation, and NGI/system temperature. Measurements conducted at NGI/system temperatures approaching body temperature provide additional mechanistic insight, particularly for hypertonic aerosols, and support integrated assessment of particle-size, delivery, and deposition outcomes rather than APSD metrics alone.
Objectives Evaporative cooling of surgical wounds during surgery was overlooked as a modifiable factor in reducing surgical site infections (SSIs). HumiGard TM is a system which delivers warm and humidified air to the wound bed intraoperatively to prevent tissue cooling and drying. This study investigated the potential for HumiGard™ to reduce bacterial load in a porcine model of spine surgery. Methods Open spine surgery was simulated in a porcine model. The wound surface was inoculated with ~10 6 CFU/mL of Staphylococcus aureus and remained exposed for 180 minutes to the ambient theatre conditions (control) or warm humidified air (HumiGard) (n=6 per group). Wounds were re-opened three days post-surgery and biopsies were collected for bacterial enumeration and histological analyses. Results The growth of Staphylococcus aureus was 84% less in the HumiGard muscles than control at Day 3 post-surgery (p=0.031). Large bacterial colonies infiltrated the deeper muscle tissues in control, while the HumiGard muscles had smaller bacterial colonies confined to the superficial zone. Neutrophil proportion in the HumiGard group (34% ± 5.1%) was lower than control (65% ± 6.1%) (p=0.005). In contrast, the proportion of mononuclear cells was higher in HumiGard tissues (66% ± 5.1%) than control (35% ± 6.1%) (p=0.005), implying a transition from the pro-inflammatory to the reparative stage of wound healing. Conclusions In this animal study, maintaining physiological temperature and humidity of open wounds during surgery reduced bacterial growth and advanced the wound healing process. HumiGard may offer a protective benefit by reducing the risk of SSIs following orthopaedic surgery.
Background: Dental treatment often requires prolonged mouth opening. This may compromise comfort during spontaneous nasal breathing and saliva swallowing, leading to stress or anxiety. A high-flow nasal cannula (HFNC) delivers warmed and humidified air at high flow rates and may improve breathing comfort; however, the feasibility of its routine use during dental treatment has not been established. Objectives: The primary objective of this pilot study is to evaluate the feasibility of conducting a definitive clinical trial to investigate the use of a HFNC during dental treatment. The secondary objective is to explore preliminary patient-centered outcomes related to stress and comfort to inform the design of future clinical trials. Methods: This single-center, open-label pilot feasibility study will be conducted at Nagasaki University Hospital, with adult patients undergoing routine full-mouth periodontal treatment participating in two treatment sessions, one without a HFNC and one with a HFNC, separated by at least four weeks. The primary feasibility outcomes include recruitment and retention rates, patient tolerance and acceptability of the HFNC, completeness of data collection, and device-related adverse events. The secondary outcomes are exploratory and include physiological stress-related parameters (pulse rate, respiratory rate, autonomic nervous system indices, and electroencephalographic alpha wave activity) and patient-reported comfort assessed using a questionnaire. Conclusions: This pilot study was designed to assess the feasibility and safety of HFNC use during full-mouth periodontal treatment and to inform the design of future definitive clinical trials. In particular, the resultant exploratory patient-centered outcomes and preliminary data may be used to guide outcome selection and sample size estimation.
Background Surgical site infection remains a serious postoperative complication following orthopedic spine surgery. Current preventative strategies aim to minimize airborne particle contamination within the operating room theatre; however additional measures have been investigated to further lower infection risk. Surgical humidification (F&P HumiGard ™ ) is designed to provide a warm humidified wound environment, and aims to minimize the effects of tissue cooling and reduce airborne particles from entering the surgical site. This study aims to evaluate the effectiveness of HumiGard to deflect airborne particles under a static wound and during a dynamic simulation of open spine surgery. Methods A cadaveric simulation of a lumbar laminectomy and L4-L5 posterolateral fusion surgery was performed under a conventional laminar downflow system. HumiGard was adhered to the surgical site prior to the incision and airborne particles (0.3 µm to 10 µm) were continuously measured at the wound using an Optical Particle Sizer. Static wound particle counts were assessed using a HumiGard ON/OFF cycling protocol to evaluate the device specific effects of HumiGard on wound particle counts. In addition, particle counts during the surgical procedure were measured. Particle counts under standard care (control) and HumiGard conditions (intervention) were compared using non-parametric statistical analysis. Results Activation of HumiGard produced immediate and pronounced reductions in particle counts under both static wound and procedural conditions. Median airborne particle counts were reduced by 96% compared to control conditions in a static wound (p < 0.0001). Under dynamic open spine surgery, median airborne particle counts were reduced by 72% compared to control conditions (p < 0.0001), excluding particle counts during diathermy use. Conclusion This study demonstrates active deflection of exogenous particles with HumiGard during a static wound and dynamic cadaveric model of open spine surgery. These findings suggest that HumiGard may be a valuable tool to minimize airborne wound contamination and infection risk during orthopedic surgery, in addition to current infection prevention protocols.
