Serum lipids in Canadian physicians To the editor: In the article "Serum cholesterol and triglyceride measurements in Canadian physicians" (Can Med Assoc J 112: 447, 1975) results were based on 2071 physicians who had volunteered to be tested at 17 medical meetings over a 5-year period. In their discussion the authors state "we did not exclude physicians who volunteered for study at more than one of the meetings". Does this mean that the figure 2071 refers to the total number of blood samples obtained rather than to the number of individuals involved? If so, since some individuals may have been tested two, three or more times, can the authors tell us how many individuals were actually tested and what were the means, percentages, etc. when calculated on the basis of persons rather than samples? T.W. ANDERSON, MA, BM
Department of epidemiology and biometrics University of Toronto Toronto, Ont.
To the editor: The number of individuals tested at each meeting is given and, as we state in the article, an individual physician could have' volunteered at more than one meeting over the 5-year period. Therefore, the figure 2071 refers to the total number of blood samples obtained and not the total number of physicians participating. When we were compiling our data we recognized this limitation but it was not easy to eliminate such duplications from the large data base. Most of the data were not collected on a computerContributions to the Correspondence section are welcomed and if considered suitable win be published as space permits. They should be typewritten double spaced and should not exceed 1½ pages in length.
ized system and they were usually handled by code in order to maintain confidentiality. We believe that the number of individuals contributing more than one sample was relatively small. We also speculated that individuals who were already aware of having hyperlipemia and who were not sufficiently motivated to undertake appropriate preventive health programs would not likely be motivated to have their high serum lipid concentrations documented again. Individuals who did adopt appropriate treatment programs would likely volunteer at a series of medical meetings. We surmise that the errors in the estimations of means and percentages were likely to be small, and were likely to be in the direction of underestimating the extent of the hyperlipemia. Since the results of our study suggested that physicians appear to have surprisingly high serum lipid concentrations, we believe that the limitations in our data handling have not greatly interfered with the overall findings. As pointed out in the paper, the most important limitation in the interpretation of our data involves the manner in which the physicians were selected; that is, this was not a random sample of physicians in Canada. We believe that it would be difficult to undertake such a truly random sampling. R.O. DAVIES, MD, PH D Ayerst Laboratories Montr6al, Qu6.
Food asphyxiation To the editor: In his letters to the Journal (Can Med Assoc J 111: 1186, 1974 and 112: 283, 1975) Dr. Lager has drawn attention to the use of sudden sharp compression of the upper abdomen as a means of relieving pharyngeal
obstruction caused by food, but there has been no scientific evidence that such a maneuver is really effective. The "caf6 coronary" is simply asphyxia from a lump of food too large to enter the esophagus and which, therefore, lodges in the hypopharynx, blocking the glottis. The most effective means of removing the obstruction is the victim's own cough, which will produce several times the pressure of an abdominal squeeze performed by someone else. Because almost everyone in this situation will cough, the chest will be relatively empty of air; it would seem difficult to "pop the cork" if the bottle is empty. A firm squeeze may break ribs, lacerate the liver, lungs or heart, rupture the stomach or cause the regurgitation of food, which would be aspirated into the lungs if the victim were unconscious, even if the squeeze itself were successful. Perhaps one of the greatest complications of vigorous compression of the upper abdomen is "winding" the victim by sudden compression of the celiac plexus. This is an old schoolboy trick and is performed exactly as described by Dr. Heimlich. It can readily cause fainting. It is recommended that if the victim is conscious, one should place his head down, encourage him to cough and administer a sharp blow between the shoulder blades. If he is unconscious, one should remove the block directly by reaching down with two fingers behind the tongue as far as possible and dragging out the material or pushing it down and backward (posteriorly) so that it is out of the airway. Artificial respiration should be performed if needed. If these procedures are unsuccessful, one should slap the victim on the back again and repeat the procedures. If the chest appears to be hyper-
CMA JOURNAL/JUNE 21, 1975/VOL. 112 1381
COMPOSITION: Each uncoated, scored, light tan tablet contains spironolactone, 25 mg. Aldactone offers an entirely new approach to the treatment of essential hypertension, edema and ascites, including resistant states. Aldactone specifically blocks the effects on the kidneys of mineralocorticoids and antagonizes the sodium retaining and water retaining effects of aldosterone which is important in the production of edema. INDICATIONS: Aldactone is indicated in the treatment of edema and ascites of congestive heart failure, hepatic cirrhosis, the nephrotic syndrome, and idiopathic edema as well as that due to malignant effusions especially if not responding well to conventional diuretics. Aldactone is also indicated for lowering blood pressure in essential hypertension, correcting hypokalemic alkalosis in severe hypertension and in the treatment of myasthenia gravis. DOSAGE: Edema-the initial recommended adult dose is one 25 mg tablet four times daily. Rarely a patient may require up to 300 mg per day and others as little as 75 mg per day. If adequate diuresis with Aldactone is not obtained within five days, Aldactizide should be substituted in its usual dosage to obtain the synergistic effect of the spironolactone and the thiazide components. In an occasional patient with severe, resistant edema, it may be necessary to add a glucocorticoid to this combined therapy. In children a dosage providing 1.5 mg of Aldactone per pound of body weight should be employed. Essential hypertension-One tablet four times a day, treatment should be continued at least two weeks. PRECAUTIONS: Other than acute renal insufficiency there are no known contraindications to Aldactone. It should be used judiciously in patients with hyponatremia or hyperkalemia. SIDE EFFECTS: Side effects are mild and infrequent; drowsiness, mental confusion and maculopapular or erythematous eruptions have occurred rarely, subsiding within forty-eight hours on discontinuation of the drug. Gynecomastia and mild androgenic manifestations have also been reported in a few patients. TOXICITY: No reports of fatal overdosage in man. No adverse effects from high dosage in chronic animal studies. Symptoms of Overdosage-True toxicity has not been reported; drowsiness, mental confusion or a maculopapular or erythematous rash has occurred rarely. These manifestations disappear promptly on discontinuance of medication. Hyperkalemia may be exacerbated. Treatment-No specific antidote. No true toxicity has occurred or is expected. Appearance of effects described above require only discontinuance of the drug. For hyperkalemia, reduce potassium intake, administer potassiu m-excreting diuretics, intravenous glucose with regular insulin or oral ion exchange resins. SUPPLY: Bottles of 100, 1,000 and 2,500 tablets. Complete prescribing information available on request.
Aldactone (SRRONOLACTONE)
the only specific, competitive aldosterone antagonist for gradual, sustained diuresis with minimal possibility of potassium loss.. .especially indicated for the digitalized patient. Searle Pharmaceuticals Oakville, Ontario
inflated, a single vigorous squeeze as recommended by Dr. Heimlich could be tried, but if not successful it should not be repeated. Repeated chest compression in this circumstance will only contribute to further depletion of whatever oxygen reserve may still remain in the lungs. Furthermore, effective clearing of the airway in its upper portion requires maximum air flow and repeated attempts will be progressively less effective. Owing to the risk of injury, vomiting, depletion of lung volume and, above all, distraction of the rescuer's attention from directly attending to the cause of the obstruction, the Heimlich maneuver should not be recommended for general use as a first-aid technique at the present time. W.M. BRUMMITF, MD lAIN M. MACKAY, MD
Department of anesthesia University of Toronto Toronto, Ont.
To the editor: In my letter (Can Med Assoc J 111: 1186, 1974) dealing with food-choking asphyxia I emphasized the importance of early diagnosis, quick action, early removal of the food bolus if possible, the Heimlich maneuver, cricothyreotomy and resuscitation, if needed. The advice of Drs. Brummitt and MacKay to have the victim bend over while one encourages him to cough and pounds him on the back may be helpful in some cases, especially in children. However, complete inversion of the victim initiates the effects of gravity and enforced expiration by visceral displacement of the diaphragm. This is relatively easy to do by the fireman's lift. Not every victim can muster an effective cough. A colleague of mine was choking on a chocolate bar while driving to his office. Every time he tried to inspire to cough, the bolus was sucked deeper into his throat. He stopped the car, leaned over quickly to open the door and in doing so compressed his abdomen, which presumably raised his diaphragm and compressed the lungs. He was then able to cough forcibly. In "Respiratory Care" Bendixen and colleagues state: "A normal cough starts generally with a quick deep inspiration of up to 2-2.5 1 of air in adults. Next the glottis is closed for about 0.2 seconds. The chest and abdominal muscles contract and the sphincters tighten in order to build up the intrathoracic and intraabdominal pressures of 100-200 cm water. The glottis opens and air is expired at velocities that approach the speed of sound carrying with it secretions of foreign material." Compare this to the adequate air flow and pressures of the Heimlich maneuver. Drs. Brummitt and MacKay suggest
that if the victim is unconscious one should remove the block with the fingers or push it down the throat. At this stage, it is most likely that the teeth would be tightly clenched. In a parallel situation in the operating room, premature insertion of an oropharyngeal airway may induce severe bronchospasm and result in great difficulty in opening the mouth, which is tightly clenched. The advice to push the bolus down the esophagus past the glottis seems dangerous to me. The food bolus may be a large piece of unchewed meat or may be mushy pie, sticky rice cake, mashed potatoes or spaghetti. Try pushing these items down the throat. The attempt may, however, induce vomiting, thereby producing the effect of a Heimlich maneuver and so dislodge the bolus. I know of a person who has had two cardiovascular accidents. He frequently chokes on meat. By sticking his fingers down his throat he induces vomiting and dislodges the bolus. Grandmother's advice was to drink some water when food went down "the wrong way". With a small bolus, the water treatment is sensible. With the victim unconscious and his teeth tightly clenched the Heimlich maneuver should be used (but preferably before unconsciousness). If this fails a cricothyreotomy should be performed, and I refer the reader to "Airway-Instantly" by Oppenheimer in the Oct. 7, 1974 issue of JAMA. In a dining area the scalpel is usually available (steak knife, broken glass) and so is the airway - for example, part of the ubiquitous ballpoint pen. The timing of the cricothyreotomy is obviously important. If the unconscious victim is supine, he should be rolled to the prone position before the Heimlich maneuver is applied. This will help to avoid aspiration of gastric contents. If one becomes the victim of food-choking asphyxia, consider falling on the edge of some object like a chair, sofa or sink and this will produce the effect of the Heimlich maneuver. Louis H. LAGER, MD, FACA
188 Giles Blvd. E. Windsor, Ont.
To the editor: The procedure for the treatment of food-choking asphyxia that Drs. Brummitt and MacKay write of has no similarity to the maneuver I have described. My maneuver is not a "bear hug.. or "squeeze", either abdominal or chest. These maneuvers could lead to internal injuries and rib fractures - in fact to all the complications they mention. The technique for the Heimlich maneuver was presented to the Society of Thoracic Surgeons in January in Montreal and is to appear
CMA JOURNAL/JUNE 21, 1975/VOL. 112 1383
Department of epidemiology and biometrics University of Toronto Toronto, Ont.
To the editor: The number of individuals tested at each meeting is given and, as we state in the article, an individual physician could have' volunteered at more than one meeting over the 5-year period. Therefore, the figure 2071 refers to the total number of blood samples obtained and not the total number of physicians participating. When we were compiling our data we recognized this limitation but it was not easy to eliminate such duplications from the large data base. Most of the data were not collected on a computerContributions to the Correspondence section are welcomed and if considered suitable win be published as space permits. They should be typewritten double spaced and should not exceed 1½ pages in length.
ized system and they were usually handled by code in order to maintain confidentiality. We believe that the number of individuals contributing more than one sample was relatively small. We also speculated that individuals who were already aware of having hyperlipemia and who were not sufficiently motivated to undertake appropriate preventive health programs would not likely be motivated to have their high serum lipid concentrations documented again. Individuals who did adopt appropriate treatment programs would likely volunteer at a series of medical meetings. We surmise that the errors in the estimations of means and percentages were likely to be small, and were likely to be in the direction of underestimating the extent of the hyperlipemia. Since the results of our study suggested that physicians appear to have surprisingly high serum lipid concentrations, we believe that the limitations in our data handling have not greatly interfered with the overall findings. As pointed out in the paper, the most important limitation in the interpretation of our data involves the manner in which the physicians were selected; that is, this was not a random sample of physicians in Canada. We believe that it would be difficult to undertake such a truly random sampling. R.O. DAVIES, MD, PH D Ayerst Laboratories Montr6al, Qu6.
Food asphyxiation To the editor: In his letters to the Journal (Can Med Assoc J 111: 1186, 1974 and 112: 283, 1975) Dr. Lager has drawn attention to the use of sudden sharp compression of the upper abdomen as a means of relieving pharyngeal
obstruction caused by food, but there has been no scientific evidence that such a maneuver is really effective. The "caf6 coronary" is simply asphyxia from a lump of food too large to enter the esophagus and which, therefore, lodges in the hypopharynx, blocking the glottis. The most effective means of removing the obstruction is the victim's own cough, which will produce several times the pressure of an abdominal squeeze performed by someone else. Because almost everyone in this situation will cough, the chest will be relatively empty of air; it would seem difficult to "pop the cork" if the bottle is empty. A firm squeeze may break ribs, lacerate the liver, lungs or heart, rupture the stomach or cause the regurgitation of food, which would be aspirated into the lungs if the victim were unconscious, even if the squeeze itself were successful. Perhaps one of the greatest complications of vigorous compression of the upper abdomen is "winding" the victim by sudden compression of the celiac plexus. This is an old schoolboy trick and is performed exactly as described by Dr. Heimlich. It can readily cause fainting. It is recommended that if the victim is conscious, one should place his head down, encourage him to cough and administer a sharp blow between the shoulder blades. If he is unconscious, one should remove the block directly by reaching down with two fingers behind the tongue as far as possible and dragging out the material or pushing it down and backward (posteriorly) so that it is out of the airway. Artificial respiration should be performed if needed. If these procedures are unsuccessful, one should slap the victim on the back again and repeat the procedures. If the chest appears to be hyper-
CMA JOURNAL/JUNE 21, 1975/VOL. 112 1381
COMPOSITION: Each uncoated, scored, light tan tablet contains spironolactone, 25 mg. Aldactone offers an entirely new approach to the treatment of essential hypertension, edema and ascites, including resistant states. Aldactone specifically blocks the effects on the kidneys of mineralocorticoids and antagonizes the sodium retaining and water retaining effects of aldosterone which is important in the production of edema. INDICATIONS: Aldactone is indicated in the treatment of edema and ascites of congestive heart failure, hepatic cirrhosis, the nephrotic syndrome, and idiopathic edema as well as that due to malignant effusions especially if not responding well to conventional diuretics. Aldactone is also indicated for lowering blood pressure in essential hypertension, correcting hypokalemic alkalosis in severe hypertension and in the treatment of myasthenia gravis. DOSAGE: Edema-the initial recommended adult dose is one 25 mg tablet four times daily. Rarely a patient may require up to 300 mg per day and others as little as 75 mg per day. If adequate diuresis with Aldactone is not obtained within five days, Aldactizide should be substituted in its usual dosage to obtain the synergistic effect of the spironolactone and the thiazide components. In an occasional patient with severe, resistant edema, it may be necessary to add a glucocorticoid to this combined therapy. In children a dosage providing 1.5 mg of Aldactone per pound of body weight should be employed. Essential hypertension-One tablet four times a day, treatment should be continued at least two weeks. PRECAUTIONS: Other than acute renal insufficiency there are no known contraindications to Aldactone. It should be used judiciously in patients with hyponatremia or hyperkalemia. SIDE EFFECTS: Side effects are mild and infrequent; drowsiness, mental confusion and maculopapular or erythematous eruptions have occurred rarely, subsiding within forty-eight hours on discontinuation of the drug. Gynecomastia and mild androgenic manifestations have also been reported in a few patients. TOXICITY: No reports of fatal overdosage in man. No adverse effects from high dosage in chronic animal studies. Symptoms of Overdosage-True toxicity has not been reported; drowsiness, mental confusion or a maculopapular or erythematous rash has occurred rarely. These manifestations disappear promptly on discontinuance of medication. Hyperkalemia may be exacerbated. Treatment-No specific antidote. No true toxicity has occurred or is expected. Appearance of effects described above require only discontinuance of the drug. For hyperkalemia, reduce potassium intake, administer potassiu m-excreting diuretics, intravenous glucose with regular insulin or oral ion exchange resins. SUPPLY: Bottles of 100, 1,000 and 2,500 tablets. Complete prescribing information available on request.
Aldactone (SRRONOLACTONE)
the only specific, competitive aldosterone antagonist for gradual, sustained diuresis with minimal possibility of potassium loss.. .especially indicated for the digitalized patient. Searle Pharmaceuticals Oakville, Ontario
inflated, a single vigorous squeeze as recommended by Dr. Heimlich could be tried, but if not successful it should not be repeated. Repeated chest compression in this circumstance will only contribute to further depletion of whatever oxygen reserve may still remain in the lungs. Furthermore, effective clearing of the airway in its upper portion requires maximum air flow and repeated attempts will be progressively less effective. Owing to the risk of injury, vomiting, depletion of lung volume and, above all, distraction of the rescuer's attention from directly attending to the cause of the obstruction, the Heimlich maneuver should not be recommended for general use as a first-aid technique at the present time. W.M. BRUMMITF, MD lAIN M. MACKAY, MD
Department of anesthesia University of Toronto Toronto, Ont.
To the editor: In my letter (Can Med Assoc J 111: 1186, 1974) dealing with food-choking asphyxia I emphasized the importance of early diagnosis, quick action, early removal of the food bolus if possible, the Heimlich maneuver, cricothyreotomy and resuscitation, if needed. The advice of Drs. Brummitt and MacKay to have the victim bend over while one encourages him to cough and pounds him on the back may be helpful in some cases, especially in children. However, complete inversion of the victim initiates the effects of gravity and enforced expiration by visceral displacement of the diaphragm. This is relatively easy to do by the fireman's lift. Not every victim can muster an effective cough. A colleague of mine was choking on a chocolate bar while driving to his office. Every time he tried to inspire to cough, the bolus was sucked deeper into his throat. He stopped the car, leaned over quickly to open the door and in doing so compressed his abdomen, which presumably raised his diaphragm and compressed the lungs. He was then able to cough forcibly. In "Respiratory Care" Bendixen and colleagues state: "A normal cough starts generally with a quick deep inspiration of up to 2-2.5 1 of air in adults. Next the glottis is closed for about 0.2 seconds. The chest and abdominal muscles contract and the sphincters tighten in order to build up the intrathoracic and intraabdominal pressures of 100-200 cm water. The glottis opens and air is expired at velocities that approach the speed of sound carrying with it secretions of foreign material." Compare this to the adequate air flow and pressures of the Heimlich maneuver. Drs. Brummitt and MacKay suggest
that if the victim is unconscious one should remove the block with the fingers or push it down the throat. At this stage, it is most likely that the teeth would be tightly clenched. In a parallel situation in the operating room, premature insertion of an oropharyngeal airway may induce severe bronchospasm and result in great difficulty in opening the mouth, which is tightly clenched. The advice to push the bolus down the esophagus past the glottis seems dangerous to me. The food bolus may be a large piece of unchewed meat or may be mushy pie, sticky rice cake, mashed potatoes or spaghetti. Try pushing these items down the throat. The attempt may, however, induce vomiting, thereby producing the effect of a Heimlich maneuver and so dislodge the bolus. I know of a person who has had two cardiovascular accidents. He frequently chokes on meat. By sticking his fingers down his throat he induces vomiting and dislodges the bolus. Grandmother's advice was to drink some water when food went down "the wrong way". With a small bolus, the water treatment is sensible. With the victim unconscious and his teeth tightly clenched the Heimlich maneuver should be used (but preferably before unconsciousness). If this fails a cricothyreotomy should be performed, and I refer the reader to "Airway-Instantly" by Oppenheimer in the Oct. 7, 1974 issue of JAMA. In a dining area the scalpel is usually available (steak knife, broken glass) and so is the airway - for example, part of the ubiquitous ballpoint pen. The timing of the cricothyreotomy is obviously important. If the unconscious victim is supine, he should be rolled to the prone position before the Heimlich maneuver is applied. This will help to avoid aspiration of gastric contents. If one becomes the victim of food-choking asphyxia, consider falling on the edge of some object like a chair, sofa or sink and this will produce the effect of the Heimlich maneuver. Louis H. LAGER, MD, FACA
188 Giles Blvd. E. Windsor, Ont.
To the editor: The procedure for the treatment of food-choking asphyxia that Drs. Brummitt and MacKay write of has no similarity to the maneuver I have described. My maneuver is not a "bear hug.. or "squeeze", either abdominal or chest. These maneuvers could lead to internal injuries and rib fractures - in fact to all the complications they mention. The technique for the Heimlich maneuver was presented to the Society of Thoracic Surgeons in January in Montreal and is to appear
CMA JOURNAL/JUNE 21, 1975/VOL. 112 1383
