Respiratory Elimination

Passive diffusion, carrier-mediated uptake, active uptake, filtration in elimination organs 

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Nomiyama K, Nomiyama H. 1974a. Respiratory elimination of organic solvents in man. Int Arch Arbeitsmed 32 85-91. 

The absorption of inhaled -hexane has been investigated in six healthy male volunteers (Veulemans et al. 1982). Three different trials were performed on each volunteer 4-hour exposure at 102 ppm -hexane 4-hour exposure at 204 ppm, and exposure during exercise on a stationary bicycle ergometer at 102 ppm. Each trial was done at least two weeks apart. Lung clearance (from alveolar air to blood) and retention were calculated from -hexane concentrations in inhaled and expired air. After exposure, /7-hcxane in exhaled air was measured for up to 4 hours to determine respiratory elimination. Retention of -hexane (calculated from lung clearance and respiratory minute volume) was approximately 20-25%... 

Dallas, C. E., Muralidhara, S., Chen, X. M., Ramanathan, R., Varkonyi, P, Gallo, J. M., Bruckner, J. V. (1994). Use of a physiologically based model to predict systemic uptake and respiratory elimination of perchloroethylene. Toxicol Appl Pharmacol 128(1), 60-68. 

Dallas CE, Muralidhara S, Chen XM, et al. 1994c. Use of a physiologically based model to predict systemic uptake and respiratory elimination of perchloroethylene. Tox Appl Pharm 128 60-68. 

At processing temperatures, most polymers emit fumes and vapors that may be irritating to the respiratory tract. This is also tme for PVC and its additives. Such irritation may extend to the skin and eyes of sensitive people. Processing emissions exposure can also be greatly reduced or eliminated by the use of properly designed and maintained exhaust ventilation. 

Elimination of virus in urine, feces, respiratory exudate... 

Industrial environments expose individuals to a plethora of airborne chemical compounds in the form of vapors, aerosols, or biphasic mixtures of both. These atmospheric contaminants primarily interface with two body surfaces the respiratory tract and the skin. Between these two routes of systemic exposure to airborne chemicals (inhalation and transdermal absorption) the respiratory tract has the larger surface area and a much greater percentage of this surface exposed to the ambient environment. Or dinary work clothing generally restricts skin exposures to the arms, neck, and head, and special protective clothing ensembles further limit or totally eliminate skin exposures, but breathing exposes much of the airway to contaminants. 

It should be noted that the primary purpose of the ventilation systems described for abrasive blasting rooms and hospital isolation rooms is to prevent or minimize exposure to hazardous substances in those persons working outside the blasting or isolation room. The ventilation system may also reduce exposure for workers inside these rooms, but often the reduction is not sufficient to eliminate the need for respiratory protection. 

PuAEMACoLOGiCAL AcTiox. Curare is stated to be almost inert when taken by mouth, owing to poor absorption by intestinal mucous membrane and the rapidity of elimination. Injected hypodermically it is a rapid and potent poison, paralysing the motor nerve-endings in striped muscle, so that voluntary movements cease and death occurs from respiratory failure. 

One of the major hazards of narcotic administration is respiratory depression, widi a decrease in the respiratory rate and depth. The most common adverse reactions include light-headedness, dizziness, sedation, constipation, anorexia, nausea, vomiting, and sweating. When diese effects occur, die primary healdi care provider may lower die dose in an effort to eliminate or decrease die intensity of die adverse reaction. Otiier adverse reactions tiiat may be seen witii die administration of an agonist narcotic analgesic include ... 

The nurse withholdsthe drug and notifiesthe primary health care provider if any one or more vital signs significantly varies from the database, if the respiratory rate is 10/min or below, or if the patient appearslethargic. In addition, it is important to determine if there are any factors (eg, noise, lights pain, discomfort) that would interfere with steep and whether these maybe controlled or eliminated. 

Personality variables, state of mind at time of withdrawal, and expectations of severity of symptoms all may affect withdrawal severity (Kleber 1981). One study found that merely providing addicts information about the withdrawal syndrome resulted in lower levels of withdrawal symptoms (Green and Gos-sop 1988). Naloxone rapidly induces a severe withdrawal syndrome, which peaks within 30 minutes and then declines rapidly. Until the antagonist is eliminated, only partial suppression of the withdrawal syndrome is possible, and then only by using very high opioid doses, which may cause respiratory depression when naloxone is metabolized. 

Large or quickly repeating doses over a period of hours can led to extreme anxiety, paranoia and even hallucinations. These effects usually disappear as the drug is eliminated from the body. The after-effects of cocaine and crack use may include fatigue and depression as people come down from the high. Excessive doses can cause death from respiratory or heart failure but this is rare. 

Haemophilus influenzae is a bacterial respiratory pathogen that causes a wide spectrum of disease ranging from colonization of the airways to bacterial meningitis. It causes considerable morbidity and mortality, especially in children less than 5 years of age. H. influenzae is either encapsulated or unencapsulated. The encapsulated strains can be further differentiated into six antigenically distinct serotypes, a through f. H. influenzae type b was primarily found in cerebrospinal fluid and blood of children with meningitis, while the unencapsulated strains were found in the upper respiratory tract of adults. Before the introduction of the vaccine, H. influenzae was responsible for 20,000 to 25,000 cases of invasive disease annually and was the most common cause of bacterial meningitis. Since the introduction of the vaccine, invasive disease due to H. influenzae type b has been nearly eliminated. 

Hypercapnia (abnormally high concentration of carbon dioxide in the blood) can develop as a result of overfeeding with both dextrose and total calories.1,37 Excess carbon dioxide production and retention can lead to acute respiratory acidosis. The excess carbon dioxide also will stimulate compensatory mechanisms, resulting in an increase in respiratory rate in order to eliminate the excess carbon dioxide via the lungs. This increase in respiratory workload can cause respiratory insufficiency that may require mechanical ventilation. Reducing total calorie and dextrose intake would result in resolution of hypercapnia if due to overfeeding. 

All of the organ systems in the body, except the reproductive system, contribute to the maintenance of homeostasis (see Table 1.1). For example, the gastrointestinal tract digests foods to provide nutrients to the body. The respiratory system obtains oxygen and eliminates carbon dioxide. The circulatory system transports all of these materials and others from one part of the body to another. The renal system eliminates wastes and plays a role in regulating blood volume and blood pressure. 

The cells of the body require a continuous supply of oxygen to produce energy and carry out their metabolic functions. Furthermore, these aerobic metabolic processes produce carbon dioxide, which must be continuously eliminated. The primary functions of the respiratory system include ... 

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