by the vigorous popularization and enforcement of preventive measures, whether they are the wearing of automobile seat belts, the wearing of safety glasses and helmets in industry, or the use of safe and well designed ladders in and around the home. Prevention must remain a paramount consideration. A second consideration is encouragement of research into not only prevention but also the epidemiology and causation of trauma. Third, information concerning all aspects of trauma must be effectively disseminated from centres where research is conducted and experience is considerable to practitioners who may be called on to give primary care in cases of trauma. Fourth, physicians particularly must be trained in the fundamental aspects of trauma and emergency care so that hospital emergency rooms can be staffed by personnel well prepared to give competent trauma care. And fifth, medical services - whether ambulance or

helicopter, emergency room or operating room, or city or country location - must be efficient, well equipped and coordinated in order to deliver the appropriate level of care. From the practical viewpoint, once a patient has sustained trauma correct management is essential. It is therefore to be hoped that the present group of papers on trauma supplemented by others (the first being that by Waddell on page 653) to be published, will facilitate discussion of trauma - a disease, regrettably, that has been labelled "the worst treated disease in modern society".4 DAVID A.E. SHEPHARD

References 1. GILL W: Multiple trauma: the wind of change. J R Coil Surg Edinb 20: 151, 1975 2. LOWE RI, BAKER RJ: Organization and function of trauma care units. / Trauma 13: 285, 1973 3. Statistics Canada: Causes of Death, Provinces by Sex and Canada by Sex and Age, cat no 84-203, 1974 4. MULLEN iT: The magnitude of the p:oblem of trauma. / Trauma 14: 1070, 1974

Correct use of aerosol inhalers Most medical equipment is technically sophisticated and efficient - as long as it is used correctly. In many instances such equipment is used in hospital by hospital personnel, and supervision and maintenance facilities are readily available. Often, however, medical equipment is used at home by patients, who may not fully understand how to use it and who do not have access to advice or maintenance; then, if the equipment has a therapeutic purpose, inefficient use may lead to ineffective therapy; for example, full therapeutic benefits are often denied the patient when aerosol inhalers are not used correctly. A recent survey of 100 physicians showed that 50% agreed that the total effectiveness of aerosols is reduced because patients do not administer them correctly. This finding is similar to those of two studies of patient use of aerosol inhalers - one study from France and the other from Scotland. The French study was of 20 asthmatic patients who apparently knew how to use aerosol canisters delivering bronchodilator drugs; only 5, however, used them effectively.1 The Scottish study revealed that 45 (14%) of 321 asthmatic patients were inefficient in using their canisters, and the authors of this study concluded that because "even after initial tuition some patients cannot use an inhaler correctly. .. regular checks of inhalation technique are therefore necessary".2 Aerosol inhalers are effective in directing small quantities of a therapeutic

agent for direct topical action into the lungs, and it is important that patients understand how to use inhalers correctly. For domestic use instructions can and should be given clearly both by the physician who prescribes an inhaler and by the pharmacist from whom the patient purchases it. Use of aerosol inhalers requires more skill on the part of the patient than does any other aspect of drug administration; it is therefore important that physicians as well as pharmacists themselves know how aerosol inhalers work. Essentially an aerosol inhaler is a propellant-powered nebulizer whose contents, which are under pressure of a liquefied or compressed gas, are released through the action of a valve. All aerosols have five features in common: a medicament, a propellant, a container, a metering valve, and an applicator (or actuator). The mechanical and functional aspects of aerosol inhalers are worth brief consideration. The medicament used in an inhaler is either in solution or suspension. A solution provides the advantage of uniform distribution, but most drugs are not soluble in chlorofluorohydrocarbons and so suspensions are more commonly used. These are more difficult to formulate, but they have the advantages of correct particle size (and so accurate control of drug in the spray) and inhalation of the required amount of active ingredient, but only a small amount of propellant. Any propellant used must be nontoxic, nonflammable, chemically inert

584 CMA JOURNAL/MARCH 19, 1977/VOL. 116

The modifier of digestive behaviour Indications: Sub-acute gastritis, chronic gastritis, gastnc sequellae of surgical procedures such as vagotomy and pyloroplasty. Under these conditions, when gastric emptying is delayed, Maxeran may relieve such symptoms as nausea, vomiting, epigastnc distress, bloating, etc. Small bowel intubation- Maxeran may facilitate and accelerate small bowel intubation. Side-effects: Drowsiness and, more rarely, insomnia, fatigue, headaches, dizziness and bowel disturbances have been reported. Parkinsonism and other estra-pyramidal syndromes have been reported infrequently. An increase in the frequency and seventy of seizures has been reported in conjunction with the administration of Maseran to epileptic patients. Precautions: Drugs with atropine-like action should not be used simultaneously with Maseran since they have a tendency to antagonize effect of this drug on gastrointestinal motility. Maxeran should not be used in conjunction with potent ganglioplegic or neuroleptic drugs since potentialion of effects might occur. Maxeran should not be used in patients with epilepsy and estrapyramidal syndromes, unless its espected benefits outweigh the risk of aggravating these symptoms. In view of the risk 01 extrapyramidal manifestations, metoclopramide should not be used in children unless a clear indication has been established. The recommended dosage of Maseran should not be esceeded since a further increase in dosage will not produce a corresponding increase in the clinical response. The dosage recommended for children should not be esceeded. Contraindications: Maseran should not be administered to patients in combination with MAO inhibitors, tricyclic antidepressants, sympathomimetics and foods with high tyramine content, since safety of such an association has not yet been established. As a safety measure, a twoweek period should elapse between using Maseran and administration of any of these drugs. The safety of use of Maseran in pregnancy has not been established. Therefore Maseran should not be used in pregnant women, unless in the opinion of the physician the espected benefits to the patient outweigh the potential risks to the fetus. Dosage and administration: For delayed gastric emptying Adults Tablets: .2 to 1 tablet (5 - 10 mg) three or four times a day before meals. Liquid: 5- lOin) (5-10mg) three or four times a day before meals. Injectable: When parenteral administration is required, 1 ampoule (10 mg) IM. or IV. (slowly) to be repeated 2 or 3 times a day if necessary. Children: (5 to 14 years): Liquid: 2.5 to 5 ml (2.5-5 mg) three times a day before meals. For small bowel intubation: Adults: One ampoule (10 mg) IV. - 15 minutes before intubation. Other routes (oral or IM.) may be used but with a greater period of latency. Children: (Sf0 14 years): 2.5 to 5 ml (2.5 - 5 mg) Availability: Tablets: Each white scored compressed tablet contains 10 mg of Metoclopramide hydrochloride. Bottles of 50 & 500 tablets. Liquid:

Each ml contains 1 mg of Metoclopramide hydrochloride. Available in bottles of 110 ml and 450 ml.

Injectable:

Each 2 ml ampoule contains 10 mg of Metoclopramide hydrochloride in a clear colourless solution. Keep away from light and heat. Available in boxes of 5 and 50 ampoules. Product monograph available upon

c.oc.c.o@ request.

PHARMACEUTIQUES LTEE PHARMACEUTICALS LTD

Laval, Que.

Canada.

and odourless. Commonly three chiorofluorohydrocarbons (propellants 11, 12 and 14) are combined in the ratio that is optimal both for product suspension and particle size. Because only small amounts of propellant are inhaled and then eliminated rapidly, the toxicity of the propellant is low when the inhaler is used according to directions. The container is made of aluminum or glass. The former is preferable because it is light and strong and inert to anhydrous products, whereas glass is heavy and fragile. The metering valve is an integral adjunct to the container for it admits the liquid phase of the aerosol into a chamber during either the up or down stroke and releases it on the reverse stroke, at the same time sealing off the liquid phase in the rest of the container. The applicator is the final part to consider. Through it the aerosol is delivered to the patient's lungs, but for this to be done effectively three requirements must be met in design and use of the applicator: patency of the ap-

plicator itself, rapid evaporation of the propellant without production of a diffuse spray and minimal deposition of spray within the applicator. Understanding of these five elements of an aerosol inhaler will facilitate correct use. In addition to these mechanical considerations, the physician should consider functional aspects of the operation of an inhaler should patients request advice on correct use. These additional points are as follows: 1. The internal pressure of propellant-powered inhalers is determined in part by the environmental temperature. Inhalers should not be used if the ambient temperature is below that of the room. 2. The inhaler should be shaken before each use. 3. The amount of active ingredient remaining in the container may be checked quite simply. If the container is placed in a small bath of water it will sink if it is full and float if empty. 4. Aerosols are usually ineffective if a patient contracts an infection of the respiratory tract.

5. Correct use is predicated on certain maneuvers, of which the patient should be reminded. It is important, for example, that the patient a) exhale fully; b) form an airtight seal between the lips and the mouthpiece of the inhaler; c) inhale deeply and slowly while activating the inhaler by pressing firmly and fully on the canister; and d) remove the inhaler, hold the breath for as long as possible and exhale through the nose. These apparently simple considerations are often not appreciated by patients. The physician can do much to ensure initial and continuing effectiveness of aerosol inhalers by explaining them to patients and checking regularly on correct use. J.R. GRAINGER General manager Allen & Hanburys Barclay Ave. Toronto, Ont.

References I. OREHEK J, GAYRARD P, GRIMAUD C, et al:

Patient error in use of bronchodilator-metered aerosols. Br Med 1 1: 76, 1976 2. PATERSON IC, CROMPTON (1K: Use of pressurized aerosols by asthmatic patients. Ibid. p 76

The climacteric syndrome: an estrogen replacement dilemma The increase in life expectancy for women over the last few generations has not been matched by a prolongation of ovarian endocrine function. In a society that now encourages greater participation by women in public, business, professional and family affairs, the decline in ovarian steroidogenesis occur& at a time when many women are still actiVe. As the waning ovarian estrogen secretion becomes aperiodic, several physical and emotional changes, commonly referred to as the climacteric syndrome, frequently (though not invariably) occur. Consequently, the problems posed by the "climacteric years" (the period during which this syndrome commonly occurs) present a challenge that encompasses many aspects of health care. The population of climacteric women is large: in the United States in 1970, of a total population of 104 million women, 27 million were 50 years of age or more.1 Extrapolating this ratio to Canada's population, approximately 3 million women are in the climacteric years. Furthermore, the North American woman at age 50 has an average life expectancy to 78 years. Although the number of women that may experience a "symptomatic menopause" is large, it is uncertain how many women have symptoms severe

enough to prompt medical care. In Jeffcoate's experience,2 25% of women seek medical advice. The cause of the symptoms constituting this syndrome is not clear. Decreased estrogen production is the most favoured cause displacing the earlier cause of elevated circulating gonadotropin concentrations from the uninhibited hypothalamic pituitary axis. It is this factor of estrogen deprivation combined with the clinical availability of estrogen that generated the medical profession's 40-year turbulent love affair with estrogen replacement as treatment for the climacteric syndrome. Two diametrically opposite beliefs have evolved. According to one, the climacteric years are a normal physiologic period associated with annoying but otherwise harmless symptoms. During this period of readjustment from one physiologic balance to another, routine hormonal therapy is unwarranted. The converse belief is that menopause is an estrogen deficiency state that requires hormone replacement.3 Although proponents of each view persist, most physicians have taken a middle position. Most Canadian women cease menstruation by 50 years of age. For some, perhaps many, this is the only symptom of the climacteric period. Although many diverse symptoms are associated

586 CMA JOURNAL/MARCH 19, 1977/VOL. 116

with the menopause, vasomotor phenomena and vulvovaginal changes are the only certain results of estrogen lack. Hot flushes typically include a sensation of warmth accompanied by a skin blush that begins in the upper chest and radiates centripetally. Sweating may accompany these flushes, or it may be an independent occurrence. The fact that descriptions of hot flushes by some patients do not fit this typical pattern suggests a vascular response to undefined autonomic neural stimulation that may not be unique to the climacteric years. The frequency and severity of hot flushes can be ameliorated by administration of estrogen. The dose of estrogen required to minimize symptoms is often well below the threshold dose required to modify the elevated serum gonadotropin concentrations that characterize ovarian failure. Other drugs may be helpful. In one prospective study, clonidine, a central antihypertensive that decreases vascular reactivity, reduced the number, severity and duration of menopausal flushes.4 Danazol (a synthetic derivative of 17 a-ethinyl testosterone), which has antigonadotropin properties, has been only partially successful in controlling hot flushes.5 Vulvar, vaginal and some urinary symptoms are due to atrophy of the

Correct use of aerosol inhalers.

by the vigorous popularization and enforcement of preventive measures, whether they are the wearing of automobile seat belts, the wearing of safety gl...
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