Biochemical Education ELSEVIER
Biochemical Education 26 (1998) 317-319
Clinical chemistry in the medical curriculum: from practical to research Frank J.M.F. Dor*, Maud I. Cleton, Gerard de Jong, Henk G. van Eijk Facul~' o]'Medk'ine, D~Tmrtment of Chemical Patholob9', Erasmus Univel:~ity Rotterdam, Rotterdam. p.o. Box 1738, The Netherlands
The haemoglobin levels of a group of healthy students aged 18-3(1 years (n = 216) were determined. These were matched with a test population of 34 wind instrument players. The average haemoglobin level of the wind players was significantly higher. © 1998 IUBMB. Published by Elsevier Science Ltd. All rights reserved. 1. I n t r o d u c t i o n
Clinical Chemistry appears as early as the second year on the curriculum of medical students of the Erasmus University (EUR). The subject is presented in the form of a second-year course in Chemical Pathology, which includes a series of lectures and a practical. In the third year a course in Clinical Chemistry is taught. Students who have passed their first year and first semester of the second year exams in Chemistry and Biochemistry are admitted to the Chemical Pathology lectures (20 hours of chemical/molecular background of pathology) and practical. The practical includes five experiments, each taking half a day to perform. The course objective of the practical is to teach students the following: Clinical chemical tests need not be complicated to be effective; - - some practical biochemical experience in laboratory settings is a necessity; - - biochemical parameters are useful in clinical practice. --
Students are taught that high-precision quantitative chemical data are essential for clinical diagnosis. Student motivation for accurate work is boosted by the fact that they submit their own samples (blood, urine) for testing. In addition, students learn to combine clinical chemical analyses with practical medicine and to estimate the relevance of the acquired data for clinical use. The practical is highly popular among second-year students (for further details see [1,2]).
The third-year course in clinical chemistry not only aims to improve students' laboratory skills, it also draws attention to the contribution of clinical chemistry to the detection, diagnosis and treatment of disease. In addition, it focuses on the relevance--and thus on the choice--of chemical tests in relation to disease and the interpretation of data.
2. F r o m p r a c t i c a l
to r e s e a r c h
In the first experiment of the Chemical Pathology Practical, students are required to determine their own level of haemoglobin, haematocrit and number of erythrocytes. To obtain samples, students perform (supervised) venepunctions on each other. In all, three tubes of blood per student are taken, two of which are sent to the Central Clinical Chemical Laboratory (CKCL) of the Academical Hospital Dijkzigt (AZR Dijkzigt) where all haematological and chemical data are determined. The third tube is used by students for their own experiments. The following day students receive the data analysis from the laboratory for comparison with their own findings. Last year a male student (Frank Dor) noticed an increase in his Hb-level (10.5 retool/l; normal values as used by CKCL: 8.2-10.2mmol/1 for males). Having excluded all known causes for this increase in Hb-level, it occurred to us that this student's intensive clarinet practice might be a clue in our quest for a cause. Inquiry among classmates revealed that indeed all wind instrument players had Hb-levels in or over high-normal values. Since no data on this subject were available in the literature, a research project was set up, in which we
0307-4412/98/$19.00 + 0.00 © 1998 IUBMB. Published by Elsevier Science Ltd. All rights reserved. P I h S 0 3 0 7 - 4 4 1 2 ( 98 )00084-3
E J. M. E Dor et al./Biochemicol Education 26 (1998) 317-319
compared Hb-levels of wind instrument players with those of a well-defined group of healthy second-year medical students.
vegetarian (y/n) - - vegan (y/n)
3.1.5. Donor blood bank 3.
Venepuncture was performed on two matching age groups. We had at our disposal, a large, statistically relevant reference group of young, healthy people, aged 18-311, N = 216:111 fcmale, 105 male. We matched this with a test population of 34 men and 10 women in the same age range, all wind instrument players, some amateurs, others semi-professional, professional or music academy students. All those approached received a letter informing them of our research project. Informed consent was obtained and registered. Venepuncture was followed by a short case history. To prevent bias, the histories were done by one person (Frank Dot) following a protocol (see below). With the help of the histories we could keep the test group free from contamination, excluding virtually all factors that might increase Hb-levels, with the exception of the playing of a wind instrument. In addition, the histories provided data on frequency, history and duration of musical practice. 3.1. The questionnaire 3.1.1. Activities influencing Hb-levels
recent, prolonged stay at high altitude (y/n) sports practised (kind of sport and frequency of practice) - - smoker/non-smoker (number of cigarettes a day) -sports practised night before venepuncture (y/n), or -disco/club visited night before venepuncturc (y/n) - - s t a y e d in smoky area (pub/club) night before venepuncture (y/n) - - amount of alcohol consumed night before venepuncture (number of glasses) ---
3.1.2. Loss of blood
melaena (y/n) bright red blood with bowel motion (y/n) -recent gastroenteritis (y/n) - - women: excessive loss of blood during menstruation (y/n) ---
- - donor blood bank (y/n) 3.1.6. Wind instrument
number of years of practice on wind instrument frequency of practice on wind instrument (number of hours a week)
All values were determined by the Sysmex NE 801) at the Central Clinical Chemical Laboratory (CKCL) of thc Academical Hospital Dijkzigt. This institute uses the following normal values for haemoglobin: - - males: 8.2-10.2 mmol/l - - females: 7.3-9.3 mmol/l
Table 1 shows the Hb-values for wind instrument players and controls. The mean values for Hb-levels in wind instrument players were significantly higher (p < 0.05) than those of the matched controls. However, the difference was marginal. No relevant data on this subject could be found in the literature. However, increased Hb-levels in people living at high altitude are well documented [3-5]. In response to low po,_, erythrocyte production is increased, resulting in a rise of Hb in the blood. Wc may assume certain parallels between wind instrument players and people living at high altitudes. The respiration frequency of a wind instrument player changes during playing, with the musician breathing only three to four times a minute, compared with about 12 times per minute under normal conditions. A deep intake of breath is followed by a period of long, controlled expiration. Playing also influences the pressure in the alveoli [6,7]. Analysis of the histories excluded other factors which could possibly be responsible for the increase in Hb-levels in the test group. We could not demonstrate a dose-effect relationship. It might be that our test group was too small or the information biased. No precise Table I M e a n Hb c o n c e n t r a t i o n in the controls and wind i n s t r u m e n t players
3.1.3. Medication Men
oral anticoagulants (y/n) - - women: oral contraceptives (y/n) -other
0.8 mmol/l (n = 34, sd = 0.07) 8.8 mmol/l (n = 10, sd = 0.14)
9.7 mmol/I (n = 105, sd = 0.06) 8.4 mmol/l (n --- 111, sd = 0,06)
F. J. M. E Dor et al./Biochemicu[ Education 26 (19981 317-319
answers were ever given to the question of frequency and duration of musical practice. People simply offered estimations of the number of hours. A clear negative correlation, however, could be demonstrated between Hb-level and the number of years of musical practice. This same mechanism of adaptation is seen in people staying at high altitudes for a prolonged period of time [8,5]. Comparison within the set of male music academy students yielded the following results. Students under the mean of 12 years of musical practice had significantly higher Hb-lcvels (9.8 retool/l, N = 12) than those over the mean of 12 years of practice (9.5 retool/I, N = 9). In addition, if these same students practised morc than 21.Shrs per week (mean) they showed significantly higher mean Hb-levels (9.8 retool/l, N = 8) than if they practised less than 21.Shrs per week (9.65 retool/l, N = 13). Those who had less than 10 years of practice and played over 22.5 hrs per week (the frequency mean of this subset) showed the highest Hb-lcvels (9.9 retool/l, N = 6). Their less zealous fellow students, practising
under 22.5 hrs per week showed a mean Hb-level of 9.7 mmol/I; N = 5. In short, very zealous students who often expose their bodies to hypoxia show increased levels of Hb in the first 10 years of musical practice. The body seems to compensate for periods of hypoxia, brought on by playing, with a corresponding increase in haemoglobin.
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