Surgery – Respiratory method or device – Means for supplying respiratory gas under positive pressure
Patent
1996-07-03
1998-11-24
Weiss, John G
Surgery
Respiratory method or device
Means for supplying respiratory gas under positive pressure
12820423, 12828312, 12820325, A61M 1600
Patent
active
058394338
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to nitric oxide treatment, and concerns in particular the use of nitric oxide in the treatment of certain lung diseases or conditions, and in apparatus for this purpose.
BACKGROUND OF THE INVENTION
There are a number of lung diseases and conditions--suffered both by humans and by other animals, and typified by asthma (an increasingly prevalent and worrying problem)--in which the peripheral parts of the lung, namely those tiny airways and air spaces known respectively as bronchioles and alveoli, constrict to restrict the flow of air therethrough. This can be extremely serious, for it is in these spaces that oxygen in the inhaled air diffuses through the lung tissue into the blood capillaries running therethrough to bind to the haemoglobin in the blood, while carbon dioxide released by the blood diffuses out and is exhaled; obviously, if the movement of air, oxygen and carbon dioxide is significantly reduced by this constriction the situation may become life threatening.
There are additionally a number of lung conditions in which the lung's small peripheral arteries--the pulmonary arteries--also constrict, typically those deep in the lungs where the oxygen tension falls as in an asthmatic attack, pneumonia, or chronic lung diseases like bronchitis and emphysema (and it should also be noted that such constriction often occurs without the causative mechanism being fully explained; this is the so-called primary pulmonary hypertension). Whatever the reason, the result is that the flow of blood to the capillaries is impaired, and the ensuing increase in the resistance to blood flow--the raised pulmonary vascular resistance--may be so severe as to cause the right ventricle of the heart to fail, and death to ensue.
Normally, the flow of blood to the capillaries of the lungs is closely matched by the flow of inhaled air to the alveoli. This allows the oxygen and carbon dioxide to diffuse evenly between blood and air. However, in lung diseases like asthma, pneumonia, bronchitis and emphysema, and where there is acute injury to the lung, such as that following generalised sepsis or the inhalation of smoke and fumes, the flow of air into the alveoli no longer matches with the flow of blood to the capillaries; air goes to parts of the lung no longer receiving blood, while elsewhere the capillaries may be receiving blood but the associated alveoli are not receiving air. It follows that the exchange of oxygen and carbon dioxide is impaired, possibly to the point where death ensues.
The lung tissues concerned are smooth muscle, which operate, to contract or relax, and then to "set" in the state achieved. The actual activator is chemical in nature, and it is usually possible to find, and apply, some other chemical that will either reverse the effect or block the activator's action. Of the several ways in which the constriction of the lung airways can be treated, and the air spaces caused to open up (dilate), effectively all involve the supply to the relevant tissues' smooth muscle of a drug--a chemical--that causes the muscle to relax (and stay relaxed). The most effective treatments for asthma and like conditions involve the inhalation as an aerosol of the chosen chemical in normally inhaled air. However, to deal with the problem of constricted small pulmonary arteries only a few relieving substances are known, and one of the most powerful--that known as prostacyclin, an extremely potent vasodilator--has to be administered on a continuous basis by infusion into a vein and so to the pulmonary arteries.
Another well-known and effective dilating agent for treating both lung problems of the blood-vessel-constriction type and of the asthma airway type is the gas nitric oxide. Nitric oxide (NO) is one of several gaseous oxides of nitrogen commonly found in nature; two others are nitrous oxide (N.sub.2 O), known as "laughing gas", and at one time used as a general anaesthetic, and nitrogen dioxide (NO.sub.2). The latter, to which nitric oxide is converted by a reaction with free o
REFERENCES:
patent: 3612049 (1971-10-01), Mohson
patent: 4681099 (1987-07-01), Sato et al.
patent: 4686974 (1987-08-01), Sato et al.
patent: 5396882 (1995-03-01), Zapol
patent: 5471977 (1995-12-01), Olsson et al.
patent: 5485827 (1996-01-01), Zapol et al.
patent: 5522381 (1996-06-01), Olsson et al.
patent: 5531218 (1996-07-01), Herbs
patent: 5542415 (1996-08-01), Brody
patent: 5570683 (1996-11-01), Zapol
Srivastava V.
Weiss John G
LandOfFree
Nitric oxide treatment does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Nitric oxide treatment, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nitric oxide treatment will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1693822