stitute for mammography for routine screening in these projects and recommend that thermography be discontinued as a routine procedure in the projects for all ages. During the past 5 years I have been a member of three expert committees reviewing procedures for breast cancer screening, two in Canada and one in the United States, and have discussed thermography with a number of expert and enthusiastic thermographers in North America. I therefore have no hesitation in agreeing with Dr. Wexier that "the value of thermography has been most seriously affected by problems of reliability and reproducibility of technique and interpretation." I also agree that further study of thermography is appropriate but I believe that it should not be considered as an initial simple screening tool unless thermographers are able to overcome the problems we both acknowledge to ensure that, in routine practice, thermography or its successors can demonstrate substantially improved reliability and reproducibility as well as sensitivity and specificity. I have, therefore, concluded in my recommendations to the National Cancer Institute and Health and Welfare Canada for a national study of breast cancer screening in Canada that thermography at its present stage of development should not be a part of the study. A.B. MILLER, MB, FRCP[C] Epidemiology unit National Cancer Institute of Canada University of Toronto Toronto, Ont.
Reference 1. New breast x-ray rules. Am Coil Radiol Bull 33: 1, 1977
Accidents in endotracheal intubation To the editor: Tracheal stenosis is probably the most common complication of endotracheal intubation, and its prevention by the use of a tube equipped with an atraumatic umbrella valve has been advocated in a previous communication (Can Med Assoc J 102: 875, 1970). However, there are other associated accidents and because these are highly unusual and unexpected they can be dangerous. The tube may become kinked and completely obstructed, as in the case described below. Prior to cholecystectomy a patient received meperidine hydrochloride, 50.0 mg, and atropine sulfate, 0.6 mg. With an intravenous infusion running satisfactorily a sleep dose of thiopentone, 0.35 g, was followed by an injection of succinylcholine chloride, 80.0 mg. Endotracheal intubation was accomplished under direct vision without difficulty and the lungs were inflated gently with oxygen and nitrous oxide. Auscultation confirmed that
the endotracheal tube was positioned correctly. After a few minutes were allowed for the effect of the short-acting relaxant to wear off, a long-acting relaxant, intended as the main basis of anesthesia, was administered. It was expected that spontaneous respiration would become established, albeit shallow owing to the effect of nitrous oxide and oxygen and the residual traces of thiopentone and meperidine. Instead, the patient became restless and slightly cyanotic, as though the nitrous oxide/oxygen mixture was not reaching the lungs. Oxygen was administered without delay, first via the tube, with only slight improvement, then by a mask over the tube. The patient became even more restless and finally the endotracheal tube was removed. A second dose of succinylcholine chloride, 80.0 mg, was given and another tube was introduced, after which the long-acting relaxant produced the expected effect and the operation proceeded. Recovery from anesthesia was complete and no untoward effects were noticed. Casual inspection of the first tube showed nothing unusual, but closer inspection discovered a long spiral slit. Binding the tube produced two openings above and below a crease where the tubal lumen was occluded totally. The reason for the difficulty in inducing anesthesia was apparent. This experience demonstrates that even the most simple and sturdy piece of apparatus may be damaged and fail to act as it should. It is a reminder that any unexpected occurrence during anesthesia demands immediate investigation regardless of the inconvenience that may be caused. N. JACKSON, MB, BS P0 Box 850 Biggar, Sask.
Survival rates in cancer patients To the editor: When assessing the merits of treatment, be it of cancer or of other disease, we need a standard for comparison. Anecdotal reports were succeeded by 5-year survival rates, and in the last decade these have been supplanted by the randomized clinical trial. Somewhere along the line we seem to have missed the point. As physicians we do not create immortality; our lot is a humble one - to alleviate suffering. We should know that our patients are going to die at a finite rate; living creates an attrition rate that can be assessed by the collection of vital statistics. Life insurance companies could not exist without such information. Without going into a lot of detail, it is possible to compare the "expected survival" of a group of patients with that achieved by cancer treatment provided that they are matched for age, sex and the era of the study. When the data are plotted on a semilogarithmic scale the expected survival is a straight line and thus becomes the standard for
Emprace&30 Acetaminophen + Codeine Analgesic-AntipyreticAntitussive
kidications: To provide enhanced analgesia in a wide variety of conditions requiring the control of moderate to severe acute or chronic pain, especially when other analgesics are insufficient: also as a non-salicylate analgesic-antipyretic-antitussive in acute cold and in other acute respiratory diseases. Adverse Effects: When used as directed, acetaminophen is virtually tree of severe toxicity or side effects.The incidence of gastrointestinal upset is less than after salicylate administration, If a rare sensitivity reaction occurs, discontinue the drug. Hypersensitivity to acetaminophen is usually manifested by a rash or urticaria. Acetaminophen poisoning can result in severe hepatic damage. Phenobarbital increases the activity of microsomal enzymes which produce a toxic metabolite and therefore acetaminophen's hepatotoxicity is enhanced. Thus, concomitant ingestion of phenobarbital may increase the likelihood of liver necrosis in acetaminophen overdose. Overdose: The literature has reported that some adults who have ingested doses in excess 0110 g should be closely monitored until it is ascertained that there is no hepatotoxicity. Symptoms: Nausea, vomiting and upper abdominal pain. Initially, CNS stimulation may be noted followed by somnolence, lethargy, or stupor. In the most severe cases a 24 hour latent period may be followed by drowsiness progressing to coma due to hepatic necrosis; in these cases death may occur 2 to 4 days following ingestionThe chief biochemical changes noted in the blood are gross elevation of liver enzymes, some elevation of bilirubin level, prolongation of prothrombin time and possibly hypoglycemia or hyperglycemia. The codeine phosphate in sufficient overdosage produces narcosis, sometimes preceded by a feeling of exhilaration and followed by convulsions. Nausea and vomiting are usually prominent symptoms.The pupils are contracted and the pulse rate is usually increased. Cardiorespiratory depression accompanied by cyanosis occurs, followed by a fall in body temperature, circulatory collapse, coma, and death. Treatment: When the possibility of an overdosage exists (approx. lOg of acetaminophen) treatment should be immediate. Although no specific treatment has been developed or accepted, ipecac-or apomorphineinduced emesis followed by 50 g of activated charcoal given orally to decrease absorption of the drug, is the best available treatment. If this is not quickly available, administer the universal antidote. Since there is no specific antidote, treatment is primarily supportive. Once overdosage with acetaminophen is established, liver studies should be carried out and followed carefully for a period of 7 days.The possibility of liver damage may be suspected by the presence of a leukocytosis in conjunction with a low erythrocyte sedimentation rate. CNS stimulation may be controlled by cautious use of an intermediate-acting barbiturate such as sodium butabarbital. If signs of codeine overdosage are present a specific antagonist such as nalorphine or levallorphan should be administered immediately. In the unconscious patient, give nalorphine in i.v. doses of 5 to 10 mg to adults or ito 2 mg to children, depending on the severity of narcosis and respiratory depression. Levallorphan is given in doses one-tenth that of nalorphine. Maintain a patent airway through the use of an oropharyngeal airway or endotracheal tube, oxygen should be administered, and respiration should be assisted by artificial respiration. Circulatory collapse and shock may be counteracted by use of dextran, plasma, or concentrated albumin and vasopressor drugs, e.g. norepinephrine. Short-acting barbiturates, e.g. thiopental, may
be used cautiously to control convulsions. Avoid the use of analeptic drugs. Dosage: ito 2 tablets every 6 hours as required. Supplied: Each round peach coloured tablet contains acetaminophen 300 mg and 30 mg of codeine phosphate. In bottles of 100. Code Number Welicome K90 Additional prescribing information available on request.
© Calmic Limited LaSalle, 0u.. *Trade Mark
C-6002
CMA JOURNAL/MARCH 4, 1978/VOL. 118 483
Reference 1. New breast x-ray rules. Am Coil Radiol Bull 33: 1, 1977
Accidents in endotracheal intubation To the editor: Tracheal stenosis is probably the most common complication of endotracheal intubation, and its prevention by the use of a tube equipped with an atraumatic umbrella valve has been advocated in a previous communication (Can Med Assoc J 102: 875, 1970). However, there are other associated accidents and because these are highly unusual and unexpected they can be dangerous. The tube may become kinked and completely obstructed, as in the case described below. Prior to cholecystectomy a patient received meperidine hydrochloride, 50.0 mg, and atropine sulfate, 0.6 mg. With an intravenous infusion running satisfactorily a sleep dose of thiopentone, 0.35 g, was followed by an injection of succinylcholine chloride, 80.0 mg. Endotracheal intubation was accomplished under direct vision without difficulty and the lungs were inflated gently with oxygen and nitrous oxide. Auscultation confirmed that
the endotracheal tube was positioned correctly. After a few minutes were allowed for the effect of the short-acting relaxant to wear off, a long-acting relaxant, intended as the main basis of anesthesia, was administered. It was expected that spontaneous respiration would become established, albeit shallow owing to the effect of nitrous oxide and oxygen and the residual traces of thiopentone and meperidine. Instead, the patient became restless and slightly cyanotic, as though the nitrous oxide/oxygen mixture was not reaching the lungs. Oxygen was administered without delay, first via the tube, with only slight improvement, then by a mask over the tube. The patient became even more restless and finally the endotracheal tube was removed. A second dose of succinylcholine chloride, 80.0 mg, was given and another tube was introduced, after which the long-acting relaxant produced the expected effect and the operation proceeded. Recovery from anesthesia was complete and no untoward effects were noticed. Casual inspection of the first tube showed nothing unusual, but closer inspection discovered a long spiral slit. Binding the tube produced two openings above and below a crease where the tubal lumen was occluded totally. The reason for the difficulty in inducing anesthesia was apparent. This experience demonstrates that even the most simple and sturdy piece of apparatus may be damaged and fail to act as it should. It is a reminder that any unexpected occurrence during anesthesia demands immediate investigation regardless of the inconvenience that may be caused. N. JACKSON, MB, BS P0 Box 850 Biggar, Sask.
Survival rates in cancer patients To the editor: When assessing the merits of treatment, be it of cancer or of other disease, we need a standard for comparison. Anecdotal reports were succeeded by 5-year survival rates, and in the last decade these have been supplanted by the randomized clinical trial. Somewhere along the line we seem to have missed the point. As physicians we do not create immortality; our lot is a humble one - to alleviate suffering. We should know that our patients are going to die at a finite rate; living creates an attrition rate that can be assessed by the collection of vital statistics. Life insurance companies could not exist without such information. Without going into a lot of detail, it is possible to compare the "expected survival" of a group of patients with that achieved by cancer treatment provided that they are matched for age, sex and the era of the study. When the data are plotted on a semilogarithmic scale the expected survival is a straight line and thus becomes the standard for
Emprace&30 Acetaminophen + Codeine Analgesic-AntipyreticAntitussive
kidications: To provide enhanced analgesia in a wide variety of conditions requiring the control of moderate to severe acute or chronic pain, especially when other analgesics are insufficient: also as a non-salicylate analgesic-antipyretic-antitussive in acute cold and in other acute respiratory diseases. Adverse Effects: When used as directed, acetaminophen is virtually tree of severe toxicity or side effects.The incidence of gastrointestinal upset is less than after salicylate administration, If a rare sensitivity reaction occurs, discontinue the drug. Hypersensitivity to acetaminophen is usually manifested by a rash or urticaria. Acetaminophen poisoning can result in severe hepatic damage. Phenobarbital increases the activity of microsomal enzymes which produce a toxic metabolite and therefore acetaminophen's hepatotoxicity is enhanced. Thus, concomitant ingestion of phenobarbital may increase the likelihood of liver necrosis in acetaminophen overdose. Overdose: The literature has reported that some adults who have ingested doses in excess 0110 g should be closely monitored until it is ascertained that there is no hepatotoxicity. Symptoms: Nausea, vomiting and upper abdominal pain. Initially, CNS stimulation may be noted followed by somnolence, lethargy, or stupor. In the most severe cases a 24 hour latent period may be followed by drowsiness progressing to coma due to hepatic necrosis; in these cases death may occur 2 to 4 days following ingestionThe chief biochemical changes noted in the blood are gross elevation of liver enzymes, some elevation of bilirubin level, prolongation of prothrombin time and possibly hypoglycemia or hyperglycemia. The codeine phosphate in sufficient overdosage produces narcosis, sometimes preceded by a feeling of exhilaration and followed by convulsions. Nausea and vomiting are usually prominent symptoms.The pupils are contracted and the pulse rate is usually increased. Cardiorespiratory depression accompanied by cyanosis occurs, followed by a fall in body temperature, circulatory collapse, coma, and death. Treatment: When the possibility of an overdosage exists (approx. lOg of acetaminophen) treatment should be immediate. Although no specific treatment has been developed or accepted, ipecac-or apomorphineinduced emesis followed by 50 g of activated charcoal given orally to decrease absorption of the drug, is the best available treatment. If this is not quickly available, administer the universal antidote. Since there is no specific antidote, treatment is primarily supportive. Once overdosage with acetaminophen is established, liver studies should be carried out and followed carefully for a period of 7 days.The possibility of liver damage may be suspected by the presence of a leukocytosis in conjunction with a low erythrocyte sedimentation rate. CNS stimulation may be controlled by cautious use of an intermediate-acting barbiturate such as sodium butabarbital. If signs of codeine overdosage are present a specific antagonist such as nalorphine or levallorphan should be administered immediately. In the unconscious patient, give nalorphine in i.v. doses of 5 to 10 mg to adults or ito 2 mg to children, depending on the severity of narcosis and respiratory depression. Levallorphan is given in doses one-tenth that of nalorphine. Maintain a patent airway through the use of an oropharyngeal airway or endotracheal tube, oxygen should be administered, and respiration should be assisted by artificial respiration. Circulatory collapse and shock may be counteracted by use of dextran, plasma, or concentrated albumin and vasopressor drugs, e.g. norepinephrine. Short-acting barbiturates, e.g. thiopental, may
be used cautiously to control convulsions. Avoid the use of analeptic drugs. Dosage: ito 2 tablets every 6 hours as required. Supplied: Each round peach coloured tablet contains acetaminophen 300 mg and 30 mg of codeine phosphate. In bottles of 100. Code Number Welicome K90 Additional prescribing information available on request.
© Calmic Limited LaSalle, 0u.. *Trade Mark
C-6002
CMA JOURNAL/MARCH 4, 1978/VOL. 118 483
