Ventilating the rectum to support respiration

 

Tokyo, Japan (May 14, 2021) — Oxygen is crucial to many forms of life. Its delivery to the organs and tissues of the body through the process of respiration is vital for most biological processes. Now, researchers at Tokyo Medical and Dental University (TMDU) have shown that oxygen can be delivered through the wall of the intestine to compensate for the reduced availability of oxygen within the body that occurs in lung diseases that cause respiratory failure.

To breathe is to live; for higher animals, respiration involves absorbing oxygen and excreting carbon dioxide at gills or in the lungs. However, some animals have evolved alternative ventilatory mechanisms: loaches, catfish, sea cucumbers and orb-weaving spiders can absorb oxygen through their hindgut to survive in situations where the availability of oxygen is limited. Inspired by these unique adaptations, the team at TMDU devised strategies to allow gas exchange through the lining of the intestine, a process termed as enteral ventilation or EVA.

„The rectum has a mesh of fine blood vessels just beneath the surface of its lining, which means that drugs administered through the anus are readily absorbed into the bloodstream,“ first author Ryo Okabe explains. „This made us wonder whether oxygen could also be delivered into the bloodstream in the same way. We used experimental models of respiratory failure in mice, pigs and rats to try out two methods: delivering oxygen into the rectum in gas form, and infusing an oxygen-rich liquid via the same route.“

The researchers prepared the lining of the rectum by rubbing it to cause inflammation and increase blood flow; these changes were confirmed by increased genetic markers and improved the effectiveness of the oxygen delivery. However, because such a preparation requirement would be unacceptable for human patients, the researchers also tried using oxygenated perfluorodecalin (PFD), a liquid that can be safely used in the human body and is already in selective clinical use, and that can carry large amounts of oxygen and carbon dioxide.

The team demonstrated that delivery of oxygen both as a gas and in liquid form was beneficial: oxygenation levels increased and behavior normalized, while survival was prolonged. The team also confirmed the improvement in oxygenation at the cellular level by immunochemical staining. Furthermore, they found that the minimal amount of PFD that was absorbed along with the oxygen caused no harm, and gut bacteria were not disrupted, indicating the safety of these methods in the animal models.

„Patients in respiratory distress can have their oxygen supply supported by this method to reduce the negative effects of oxygen deprivation while the underlying condition is being treated,“ foresees Takanori Takebe, corresponding author. „Enteral ventilation showed great promise in our asphyxia-like experimental model. The next steps will be to test safety of the EVA approach with more profound mechanistic understanding by which it works; and to establish effectiveness in humans in a clinical setting.“

Conventional therapeutic respiratory support comprises complex technological protocols such as ventilators and artificial lungs. The current SARS-CoV-2 pandemic has highlighted the high need for development of less invasive alternatives such as EVA for short-term support of respiratory function. These new findings from the researchers at TMDU may pave the way for new ventilation strategies in the future.

 

 

 

The article, „Mammalian Enteral Ventilation Ameliorates Respiratory Failure“ was published in Med at DOI:10.1016/j.medj.2021.04.004

 

 

 

Image: Based on the fact that loaches have intestinal respiration under hypoxic conditions, the efficacy of the EVA method was examined in mammals such as mice and pigs. The EVA method may be effective for patients with respiratory failure. Credit: Institute of Research,TMDU

 

 


Tokyo Medical and Dental University, 14.05.2021 (tB).

Schlagwörter: ,

MEDICAL NEWS

IU School of Medicine researchers develop blood test for anxiety
COVID-19 pandemic increased rates and severity of depression, whether people…
COVID-19: Bacterial co-infection is a major risk factor for death,…
Regenstrief-led study shows enhanced spiritual care improves well-being of ICU…
Hidden bacteria presents a substantial risk of antimicrobial resistance in…

SCHMERZ PAINCARE

Hydromorphon Aristo® long ist das führende Präferenzpräparat bei Tumorschmerz
Sorgen und Versorgen – Schmerzmedizin konkret: „Sorge als identitätsstiftendes Element…
Problem Schmerzmittelkonsum
Post-Covid und Muskelschmerz
Kopfschmerz bei Übergebrauch von Schmerz- oder Migränemitteln

DIABETES

Wie das Dexom G7 abstrakte Zahlen mit Farben greifbar macht…
Diabetes mellitus: eine der großen Volkskrankheiten im Blickpunkt der Schmerzmedizin
Suliqua®: Einfacher hin zu einer guten glykämischen Kontrolle
Menschen mit Diabetes während der Corona-Pandemie unterversorgt? Studie zeigt auffällige…
Suliqua® zur Therapieoptimierung bei unzureichender BOT

ERNÄHRUNG

Positiver Effekt der grünen Mittelmeerdiät auf die Aorta
Natriumaufnahme und Herz-Kreislaufrisiko
Tierwohl-Fleisch aus Deutschland nur mäßig attraktiv in anderen Ländern
Diät: Gehirn verstärkt Signal an Hungersynapsen
Süßigkeiten verändern unser Gehirn

ONKOLOGIE

Strahlentherapie ist oft ebenso effizient wie die OP: Neues vom…
Zanubrutinib bei chronischer lymphatischer Leukämie: Zusatznutzen für bestimmte Betroffene
Eileiter-Entfernung als Vorbeugung gegen Eierstockkrebs akzeptiert
Antibiotika als Störfaktor bei CAR-T-Zell-Therapie
Bauchspeicheldrüsenkrebs: Spezielle Diät kann Erfolg der Chemotherapie beeinflussen

MULTIPLE SKLEROSE

Multiple Sklerose: Aktuelle Immunmodulatoren im Vergleich
Neuer Biomarker für Verlauf von Multipler Sklerose
Multiple Sklerose: Analysen aus Münster erhärten Verdacht gegen das Epstein-Barr-Virus
Aktuelle Daten zu Novartis Ofatumumab und Siponimod bestätigen Vorteil des…
Multiple Sklerose durch das Epstein-Barr-Virus – kommt die MS-Impfung?

PARKINSON

Meilenstein in der Parkinson-Forschung: Neuer Alpha-Synuclein-Test entdeckt die Nervenerkrankung vor…
Neue Erkenntnisse für die Parkinson-Therapie
Cochrane Review: Bewegung hilft, die Schwere von Bewegungssymptomen bei Parkinson…
Technische Innovationen für eine maßgeschneiderte Parkinson-Diagnostik und Therapie
Biomarker und Gene: neue Chancen und Herausforderungen für die Parkinson-Diagnose…