Heated humidified high-flow therapy

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High-flow therapy
HFT diagram.png
Illustration of a patient using HFT device
Other namesHigh flow nasal cannula
ICD-10-PCS Z99.81

Heated humidified high-flow therapy, often simply called high flow therapy , is a type of respiratory support that delivers a flow of medical gas to a patient of up to 60 liters per minute and 100% oxygen through a large bore or high flow nasal cannula. Primarily studied in neonates, it has also been found effective in some adults to treat hypoxemia and work of breathing issues. The key components of it are a gas blender, heated humidifier, heated circuit, and cannula. [1]

Contents

History

The development of heated humidified high flow started in 1999 with Vapotherm introducing the concept of high flow use with race horses. [2]

High flow was approved by the U.S. Food and Drug Administration in early 2000s and used as an alternative to positive airway pressure for treatment of apnea of prematurity in neonates. [3] The term high flow is relative to the size of the patient which is why the flow rate used in children is done by weight as just a few liters can meet the inspiratory demands of a neonate unlike in adults [4] It has since become popular for use in adults for respiratory failure [5]

Mechanism

The traditional low flow system used for medical gas delivery is the Nasal cannula which is limited to the delivery of 1–6 L/min of oxygen or up to 15 L/min in certain types. This is because even with quiet breathing, the inspiratory flow rate at the nares of an adult usually exceeds 30 L/min. Therefore, the oxygen provided is diluted with room air during inspiration. [6] Being a high flow system means that it meets or exceeds the flow demands of the patient.

Oxygenation

Since it is a high flow system, it is able to maintain the wearers fraction of inhaled oxygen (FiO2) at the set rate because they shouldn't be entraining ambient air. However, this may not be the case in patients who are poorly compliant with the therapy and are actively breathing through their mouth. [7]

Ventilation

The flow can wash out some of the dead space in the upper airway. This can reduce slightly the amount of carbon dioxide rebreathed. [7]

There is a correlation of the flow rate to mean airway pressure and in some subjects there has been an increase in lung volumes and decrease in respiratory rate. [8] However, positive end expiratory pressure has only been measured at less 3 cmH2O meaning it is not able to provide close to what a closed ventilatory system could provide. [9] In neonates it has been found, however, with a good fit and mouth closed, it can provide end expiratory pressure comparable to nasal continuous positive airway perssure. [10]

Humidification

The higher the flow, the more important proper humidification and heating of the flow becomes to prevent tissue irritation and mucous drying. It has been found that long term use of flows of 20-25 L/min can help reduce symptoms of chronic obstructive pulmonary disease. This is because, heat and humidity help mucociliary clearance. [11] [12] This is the reason why high-flow therapy is assumed to help with mucus clearance better than other less humidified methodologies.

Medical use

Classic Style High Flow Nasal Cannula.png

High-flow therapy is useful in patients that are spontaneously breathing but are in some type of respiratory failure. These are hypoxemic and certain cases of hypercapnic respiratory failure stemming from exacerbations of asthma and chronic obstructive pulmonary disease, bronchiolitis, pneumonia, and congestive heart failure are all possible situations where high-flow therapy may be indicated. [13]

Newborn babies

High-flow therapy has shown to be useful in neonatal intensive care settings for premature infants with Infant respiratory distress syndrome, [14] as it prevents many infants from needing more invasive ventilatory treatments.

Due to the decreased stress of effort needed to breathe, the neonatal body is able to spend more time utilizing metabolic efforts elsewhere, which causes decreased days on a mechanical ventilator, faster weight gain, and overall decreased hospital stay entirely. [15]

High-flow therapy has been successfully implemented in infants and older children. The cannula improves the respiratory distress, the oxygen saturation, and the patient's comfort. Its mechanism of action is the application of mild positive airway pressure and lung volume recruitment. [16]

Hypoxemic respiratory failure

In high-flow therapy, clinicians can deliver higher FiO2 than is possible with typical oxygen delivery therapy without the use of a non-rebreather mask or tracheal intubation. [17] Some patients requiring respiratory support for bronchospasm benefit using air delivered by high-flow therapy without additional oxygen. [18] Patients can speak during use of high-flow therapy. As this is a non-invasive therapy, it avoids the risk of ventilator-associated pneumonia.

Use of nasal high flow in acute hypoxemic respiratory failure does not affect mortality or length of stay either in hospital or in the intensive care unit. It can however reduce the need for tracheal intubation and escalation of oxygenation and respiratory support. [19] [20]

Hypercapnic respiratory failure

Stable patients with hypercapnia on high-flow therapy have been found to have their carbon dioxide levels decrease similar amounts to noninvasive treatment, but evidence is still limited as to its efficacy and currently the practice guideline is still to use noninvasive ventilation for those with exacerbations of chronic obstructive pulmonary disease and acidosis. [21]

Other uses

Heated humidified high-flow therapy has been used in spontaneously breathing patients with during general anesthesia to facilitate surgery for airway obstruction. [22]

High flow therapy is useful in the treatment of sleep apnea. [23]

Related Research Articles

<span class="mw-page-title-main">Sleep apnea</span> Disorder involving pauses in breathing during sleep

Sleep apnea, also spelled sleep apnoea, is a sleep disorder in which pauses in breathing or periods of shallow breathing during sleep occur more often than normal. Each pause can last for a few seconds to a few minutes and they happen many times a night. In the most common form, this follows loud snoring. A choking or snorting sound may occur as breathing resumes. Because the disorder disrupts normal sleep, those affected may experience sleepiness or feel tired during the day. In children, it may cause hyperactivity or problems in school.

<span class="mw-page-title-main">Respiratory failure</span> Inadequate gas exchange by the respiratory system

Respiratory failure results from inadequate gas exchange by the respiratory system, meaning that the arterial oxygen, carbon dioxide, or both cannot be kept at normal levels. A drop in the oxygen carried in the blood is known as hypoxemia; a rise in arterial carbon dioxide levels is called hypercapnia. Respiratory failure is classified as either Type 1 or Type 2, based on whether there is a high carbon dioxide level, and can be acute or chronic. In clinical trials, the definition of respiratory failure usually includes increased respiratory rate, abnormal blood gases, and evidence of increased work of breathing. Respiratory failure causes an altered mental status due to ischemia in the brain.

<span class="mw-page-title-main">Mechanical ventilation</span> Method to mechanically assist or replace spontaneous breathing

Mechanical ventilation or assisted ventilation is the medical term for using a machine called a ventilator to fully or partially provide artificial ventilation. Mechanical ventilation helps move air into and out of the lungs, with the main goal of helping the delivery of oxygen and removal of carbon dioxide. Mechanical ventilation is used for many reasons, including to protect the airway due to mechanical or neurologic cause, to ensure adequate oxygenation, or to remove excess carbon dioxide from the lungs. Various healthcare providers are involved with the use of mechanical ventilation and people who require ventilators are typically monitored in an intensive care unit.

<span class="mw-page-title-main">Obesity hypoventilation syndrome</span> Condition in which severely overweight people fail to breathe rapidly or deeply enough

Obesity hypoventilation syndrome (OHS) is a condition in which severely overweight people fail to breathe rapidly or deeply enough, resulting in low oxygen levels and high blood carbon dioxide (CO2) levels. The syndrome is often associated with obstructive sleep apnea (OSA), which causes periods of absent or reduced breathing in sleep, resulting in many partial awakenings during the night and sleepiness during the day. The disease puts strain on the heart, which may lead to heart failure and leg swelling.

<span class="mw-page-title-main">Positive airway pressure</span> Mechanical ventilation in which airway pressure is always above atmospheric pressure

Positive airway pressure (PAP) is a mode of respiratory ventilation used in the treatment of sleep apnea. PAP ventilation is also commonly used for those who are critically ill in hospital with respiratory failure, in newborn infants (neonates), and for the prevention and treatment of atelectasis in patients with difficulty taking deep breaths. In these patients, PAP ventilation can prevent the need for tracheal intubation, or allow earlier extubation. Sometimes patients with neuromuscular diseases use this variety of ventilation as well. CPAP is an acronym for "continuous positive airway pressure", which was developed by Dr. George Gregory and colleagues in the neonatal intensive care unit at the University of California, San Francisco. A variation of the PAP system was developed by Professor Colin Sullivan at Royal Prince Alfred Hospital in Sydney, Australia, in 1981.

<span class="mw-page-title-main">Bronchiolitis</span> Blockage of the small airways in the lungs due to a viral infection

Bronchiolitis is inflammation of the small airways in the lungs. Acute bronchiolitis is due to a viral infection usually affecting children younger than two years of age. Symptoms may include fever, cough, runny nose, wheezing, and breathing problems. More severe cases may be associated with nasal flaring, grunting, or the skin between the ribs pulling in with breathing. If the child has not been able to feed properly, signs of dehydration may be present.

<span class="mw-page-title-main">Oxygen therapy</span> Use of oxygen as a medical treatment

Oxygen therapy, also referred to as supplemental oxygen, is the use of oxygen as medical treatment. Supplemental oxygen can also refer to the use of oxygen enriched air at altitude. Acute indications for therapy include hypoxemia, carbon monoxide toxicity and cluster headache. It may also be prophylactically given to maintain blood oxygen levels during the induction of anesthesia. Oxygen therapy is often useful in chronic hypoxemia caused by conditions such as severe COPD or cystic fibrosis. Oxygen can be delivered via nasal cannula, face mask, or endotracheal intubation at normal atmospheric pressure, or in a hyperbaric chamber. It can also be given through bypassing the airway, such as in ECMO therapy.

Upper airway resistance syndrome (UARS) is a sleep disorder characterized by the narrowing of the airway that can cause disruptions to sleep. The symptoms include unrefreshing sleep, fatigue, sleepiness, chronic insomnia, and difficulty concentrating. UARS can be diagnosed by polysomnograms capable of detecting Respiratory Effort-related Arousals. It can be treated with lifestyle changes, orthodontics, surgery, or CPAP therapy. UARS is considered a variant of sleep apnea, although some scientists and doctors believe it to be a distinct disorder.

<span class="mw-page-title-main">Nasal cannula</span> Medical device to deliver supplemental oxygen

The nasal cannula (NC) is a device used to deliver supplemental oxygen or increased airflow to a patient or person in need of respiratory help. This device consists of a lightweight tube which on one end splits into two prongs which are placed in the nostrils curving toward the sinuses behind the nose, and from which a mixture of air and oxygen flows. The other end of the tube is connected to an oxygen supply such as a portable oxygen generator, or a wall connection in a hospital via a flowmeter. The cannula is generally attached to the patient by way of the tube hooking around the patient's ears or by an elastic headband, and the prongs curve toward the. The earliest, and most widely used form of adult nasal cannula carries 1–3 litres of oxygen per minute.

<span class="mw-page-title-main">Non-invasive ventilation</span> Breathing support administered through a face mask

Non-invasive ventilation (NIV) is the use of breathing support administered through a face mask, nasal mask, or a helmet. Air, usually with added oxygen, is given through the mask under positive pressure; generally the amount of pressure is alternated depending on whether someone is breathing in or out. It is termed "non-invasive" because it is delivered with a mask that is tightly fitted to the face or around the head, but without a need for tracheal intubation. While there are similarities with regard to the interface, NIV is not the same as continuous positive airway pressure (CPAP), which applies a single level of positive airway pressure throughout the whole respiratory cycle; CPAP does not deliver ventilation but is occasionally used in conditions also treated with NIV.

<span class="mw-page-title-main">Obstructive sleep apnea</span> Sleeping and breathing disorder

Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder and is characterized by recurrent episodes of complete or partial obstruction of the upper airway leading to reduced or absent breathing during sleep. These episodes are termed "apneas" with complete or near-complete cessation of breathing, or "hypopneas" when the reduction in breathing is partial. In either case, a fall in blood oxygen saturation, a disruption in sleep, or both, may result. A high frequency of apneas or hypopneas during sleep may interfere with the quality of sleep, which – in combination with disturbances in blood oxygenation – is thought to contribute to negative consequences to health and quality of life. The terms obstructive sleep apnea syndrome (OSAS) or obstructive sleep apnea–hypopnea syndrome (OSAHS) may be used to refer to OSA when it is associated with symptoms during the daytime.

Apnea of prematurity is a disorder in infants who are preterm that is defined as cessation of breathing by that lasts for more than 20 seconds and/or is accompanied by hypoxia or bradycardia. Apnea of prematurity is often linked to earlier prematurity. Apnea is traditionally classified as either obstructive, central, or mixed. Obstructive apnea may occur when the infant's neck is hyperflexed or conversely, hyperextended. It may also occur due to low pharyngeal muscle tone or to inflammation of the soft tissues, which can block the flow of air though the pharynx and vocal cords. Central apnea occurs when there is a lack of respiratory effort. This may result from central nervous system immaturity, or from the effects of medications or illness. Many episodes of apnea of prematurity may start as either obstructive or central, but then involve elements of both, becoming mixed in nature.

The venturi mask, also known as an air-entrainment mask, is a medical device to deliver a known oxygen concentration to patients on controlled oxygen therapy. The mask was invented by Moran Campbell at McMaster University Medical School as a replacement for intermittent oxygen treatment. Dr. Campbell was fond of quoting John Scott Haldane's description of intermittent oxygen treatment; "bringing a drowning man to the surface – occasionally". By contrast the venturi mask offered a constant supply of oxygen at a much more precise range of concentrations.

<span class="mw-page-title-main">Continuous positive airway pressure</span> Form of ventilator which applies mild air pressure continuously to keep airways open

Continuous positive airway pressure (CPAP) is a form of positive airway pressure (PAP) ventilation in which a constant level of pressure greater than atmospheric pressure is continuously applied to the upper respiratory tract of a person. The application of positive pressure may be intended to prevent upper airway collapse, as occurs in obstructive sleep apnea, or to reduce the work of breathing in conditions such as acute decompensated heart failure. CPAP therapy is highly effective for managing obstructive sleep apnea. Compliance and acceptance of use of CPAP therapy can be a limiting factor, with 8% of people stopping use after the first night and 50% within the first year.

<span class="mw-page-title-main">Acute exacerbation of chronic obstructive pulmonary disease</span> Medical condition

An acute exacerbation of chronic obstructive pulmonary disease, or acute exacerbations of chronic bronchitis (AECB), is a sudden worsening of chronic obstructive pulmonary disease (COPD) symptoms including shortness of breath, quantity and color of phlegm that typically lasts for several days.

In some individuals, the effect of oxygen on chronic obstructive pulmonary disease is to cause increased carbon dioxide retention,

Central sleep apnea (CSA) or central sleep apnea syndrome (CSAS) is a sleep-related disorder in which the effort to breathe is diminished or absent, typically for 10 to 30 seconds either intermittently or in cycles, and is usually associated with a reduction in blood oxygen saturation. CSA is usually due to an instability in the body's feedback mechanisms that control respiration. Central sleep apnea can also be an indicator of Arnold–Chiari malformation.

<span class="mw-page-title-main">Chronic obstructive pulmonary disease</span> Lung disease involving long-term poor airflow

Chronic obstructive pulmonary disease (COPD) is a type of progressive lung disease characterized by long-term respiratory symptoms and airflow limitation. The main symptoms of COPD include shortness of breath and a cough, which may or may not produce mucus. COPD progressively worsens, with everyday activities such as walking or dressing becoming difficult. While COPD is incurable, it is preventable and treatable. The two most common types of COPD are emphysema and chronic bronchitis and have been the two classic COPD phenotypes. However, this basic dogma has been challenged as varying degrees of co-existing emphysema, chronic bronchitis, and potentially significant vascular diseases have all been acknowledged in those with COPD, giving rise to the classification of other phenotypes or subtypes. Emphysema is defined as enlarged airspaces (alveoli) whose walls have broken down resulting in permanent damage to the lung tissue. Chronic bronchitis is defined as a productive cough that is present for at least three months each year for two years. Both of these conditions can exist without airflow limitation when they are not classed as COPD. Emphysema is just one of the structural abnormalities that can limit airflow and can exist without airflow limitation in a significant number of people. Chronic bronchitis does not always result in airflow limitation but in young adults who smoke the risk of developing COPD is high. Many definitions of COPD in the past included emphysema and chronic bronchitis, but these have never been included in GOLD report definitions. Emphysema and chronic bronchitis remain the predominant phenotypes of COPD but there is often overlap between them and a number of other phenotypes have also been described. COPD and asthma may coexist and converge in some individuals. COPD is associated with low-grade systemic inflammation.

Bubble CPAP is a non-invasive ventilation strategy for newborns with infant respiratory distress syndrome (IRDS). It is one of the methods by which continuous positive airway pressure (CPAP) is delivered to a spontaneously breathing newborn to maintain lung volumes during expiration. With this method, blended and humidified oxygen is delivered via short binasal prongs or a nasal mask and pressure in the circuit is maintained by immersing the distal end of the expiratory tubing in water. The depth to which the tubing is immersed underwater determines the pressure generated in the airways of the infant. As the gas flows through the system, it "bubbles" out and prevents buildup of excess pressures.

<span class="mw-page-title-main">Glossary of breathing apparatus terminology</span> Definitions of technical terms used in connection with breathing apparatus

A breathing apparatus or breathing set is equipment which allows a person to breathe in a hostile environment where breathing would otherwise be impossible, difficult, harmful, or hazardous, or assists a person to breathe. A respirator, medical ventilator, or resuscitator may also be considered to be breathing apparatus. Equipment that supplies or recycles breathing gas other than ambient air in a space used by several people is usually referred to as being part of a life-support system, and a life-support system for one person may include breathing apparatus, when the breathing gas is specifically supplied to the user rather than to the enclosure in which the user is the occupant.

References

  1. ↑ Nishimura M (April 2016). "High-Flow Nasal Cannula Oxygen Therapy in Adults: Physiological Benefits, Indication, Clinical Benefits, and Adverse Effects". Respiratory Care. 61 (4): 529–541. doi: 10.4187/respcare.04577 . PMID   27016353. S2CID   11360190.
  2. ↑ Waugh J. "High Flow Oxygen Delivery" (PDF). Trends in Noninvasive Respiratory Support: Continuum of Care. Clinical Foundations. Archived from the original (PDF) on 24 April 2014. Retrieved 24 April 2014.
    • USpatent (expired) 4722334,Blackmer RH, Hedman JW,"Method and apparatus for pulmonary and cardiovascular conditioning of racehorses and competition animals",issued 1988-02-02
  3. ↑ Sreenan C, Lemke RP, Hudson-Mason A, Osiovich H (May 2001). "High-flow nasal cannulae in the management of apnea of prematurity: a comparison with conventional nasal continuous positive airway pressure". Pediatrics. 107 (5): 1081–1083. doi:10.1542/peds.107.5.1081. PMID   11331690.
  4. ↑ Ramnarayan P, Richards-Belle A, Drikite L, Saull M, Orzechowska I, Darnell R, et al. (April 2022). "Effect of High-Flow Nasal Cannula Therapy vs Continuous Positive Airway Pressure Following Extubation on Liberation From Respiratory Support in Critically Ill Children: A Randomized Clinical Trial". JAMA. 327 (16): 1555–1565. doi:10.1001/jama.2022.3367. PMC   8990361 . PMID   35390113.
  5. ↑ Spicuzza L, Schisano M (2020). "High-flow nasal cannula oxygen therapy as an emerging option for respiratory failure: the present and the future". Therapeutic Advances in Chronic Disease. 11: 2040622320920106. doi:10.1177/2040622320920106. PMC   7238775 . PMID   32489572.
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  8. ↑ Parke, Rachael L.; Bloch, Andreas; McGuinness, Shay P. (2015-10-01). "Effect of Very-High-Flow Nasal Therapy on Airway Pressure and End-Expiratory Lung Impedance in Healthy Volunteers". Respiratory Care. 60 (10): 1397–1403. doi: 10.4187/respcare.04028 . ISSN   0020-1324. PMID   26329355.
  9. ↑ Helviz, Yigal; Einav, Sharon (2018-03-20). "A Systematic Review of the High-flow Nasal Cannula for Adult Patients". Critical Care. 22 (1): 71. doi: 10.1186/s13054-018-1990-4 . ISSN   1364-8535. PMC   5861611 . PMID   29558988.
  10. ↑ Dysart K, Miller TL, Wolfson MR, Shaffer TH (October 2009). "Research in high flow therapy: mechanisms of action". Respiratory Medicine. 103 (10): 1400–1405. doi: 10.1016/j.rmed.2009.04.007 . PMID   19467849. (Review).
  11. ↑ Rea H, McAuley S, Jayaram L, Garrett J, Hockey H, Storey L, et al. (April 2010). "The clinical utility of long-term humidification therapy in chronic airway disease". Respiratory Medicine. 104 (4): 525–533. doi: 10.1016/j.rmed.2009.12.016 . PMID   20144858.
  12. ↑ Hasani A, Chapman TH, McCool D, Smith RE, Dilworth JP, Agnew JE (2008). "Domiciliary humidification improves lung mucociliary clearance in patients with bronchiectasis". Chronic Respiratory Disease. 5 (2): 81–86. doi: 10.1177/1479972307087190 . PMID   18539721. S2CID   206736621.
  13. ↑ Veenstra P, Veeger NJ, Koppers RJ, Duiverman ML, van Geffen WH (2022-10-05). "High-flow nasal cannula oxygen therapy for admitted COPD-patients. A retrospective cohort study". PLOS ONE. 17 (10): e0272372. Bibcode:2022PLoSO..1772372V. doi: 10.1371/journal.pone.0272372 . PMC   9534431 . PMID   36197917.
  14. ↑ Shoemaker MT, Pierce MR, Yoder BA, DiGeronimo RJ (February 2007). "High flow nasal cannula versus nasal CPAP for neonatal respiratory disease: a retrospective study". Journal of Perinatology. 27 (2): 85–91. doi: 10.1038/sj.jp.7211647 . PMID   17262040. S2CID   25835575.
  15. ↑ Holleman-Duray D, Kaupie D, Weiss MG (December 2007). "Heated humidified high-flow nasal cannula: use and a neonatal early extubation protocol". Journal of Perinatology. 27 (12): 776–781. doi: 10.1038/sj.jp.7211825 . PMID   17855805.
  16. ↑ Spentzas T, Minarik M, Patters AB, Vinson B, Stidham G (2009-10-01). "Children with respiratory distress treated with high-flow nasal cannula". Journal of Intensive Care Medicine. 24 (5): 323–328. doi:10.1177/0885066609340622. PMID   19703816. S2CID   25585432.
  17. ↑ Roca O, Riera J, Torres F, Masclans JR (April 2010). "High-flow oxygen therapy in acute respiratory failure". Respiratory Care. 55 (4): 408–413. PMID   20406507.
  18. ↑ Waugh JB, Granger WM (August 2004). "An evaluation of 2 new devices for nasal high-flow gas therapy". Respiratory Care. 49 (8): 902–906. PMID   15271229.
  19. ↑ Rochwerg B, Granton D, Wang DX, Helviz Y, Einav S, Frat JP, et al. (May 2019). "High flow nasal cannula compared with conventional oxygen therapy for acute hypoxemic respiratory failure: a systematic review and meta-analysis". Intensive Care Medicine. 45 (5): 563–572. doi:10.1007/s00134-019-05590-5. PMID   30888444. S2CID   83463457.
  20. ↑ Veenstra P, Veeger NJ, Koppers RJ, Duiverman ML, van Geffen WH (2022-10-05). "High-flow nasal cannula oxygen therapy for admitted COPD-patients. A retrospective cohort study". PLOS ONE. 17 (10): e0272372. Bibcode:2022PLoSO..1772372V. doi: 10.1371/journal.pone.0272372 . PMC   9534431 . PMID   36197917.
  21. ↑ Spicuzza, Lucia; Schisano, Matteo (2020). "High-flow nasal cannula oxygen therapy as an emerging option for respiratory failure: the present and the future". Therapeutic Advances in Chronic Disease. 11: 204062232092010. doi:10.1177/2040622320920106. ISSN   2040-6223. PMC   7238775 . PMID   32489572.
  22. ↑ Booth AW, Vidhani K, Lee PK, Thomsett CM (March 2017). "SponTaneous Respiration using IntraVEnous anaesthesia and Hi-flow nasal oxygen (STRIVE Hi) maintains oxygenation and airway patency during management of the obstructed airway: an observational study". British Journal of Anaesthesia. 118 (3): 444–451. doi:10.1093/bja/aew468. PMC   5409133 . PMID   28203745.
  23. ↑ McGinley BM, Patil SP, Kirkness JP, Smith PL, Schwartz AR, Schneider H (July 2007). "A nasal cannula can be used to treat obstructive sleep apnea". American Journal of Respiratory and Critical Care Medicine. 176 (2): 194–200. doi:10.1164/rccm.200609-1336OC. PMC   1994212 . PMID   17363769.
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