CLINICAL
PAEDIATRICS
Evaluating growth hormone treatment Barbara Wardhaugh RGN, RSCN. is Research Staff Nurse, Royal Hospital for Sick Children, Edinburgh.
The consequences in later lifefor people whose growth in childhood has been restricted can be profound, often with severe emotional or psychological effects. The author defines the causes of short stature and describes clinical trials being undertaken to evaluate the use of growth hormone in children who do not appear to have growth hormone deficiency.
Disturbing prejudices against people who are short in stature continue to exist: such people may be regarded with contempt, treated as being younger than their years at school and work, and called various derisory nicknames. Children and adults who form the focus of these kinds of attacks may be profoundly affected by them. They may feel that they are not taken seriously by their peers, and are con sidered incapable of doing certain jobs or of being suitable candidates for promotion in the workplace. I have become aware of this prejudice in my work as a research nurse looking into growth in children and the use of growth hormone. This article offers a summary of normal growth in children and the causes of short stature, but concentrates on current clinical research trials on the treatment of children who do not have growth hormone deficiency but who are nev ertheless of short stature - so-called ‘short normal children’. Growth starts at the moment of conception from a single cell, and continues rapidly in the months up to birth. Thereafter, growth can be summarised as having three distinct phases: • There is a period of fast growth during infan cy, although this represents the continuation of deceleration in growth that started after a peak in utero at seven months • There follows a slow decline in rateofgrowth during the prepubertal years (2-10 years),
Fig. 1. Growth promotion and metabolism Hypothalamus releases IRH
GHRIH (somatostatin)
"x Anterior pituitary Growth hormone
^ Growth promotion
Skeletal
Extra-skeletal
^x Intermediary metabolism
y \
Fat
Carbohydrate
although the child usually grows between five and six centimetres per year during this time • The final phase depends on the sex of the child. Girls have their growth spurt at the beginning of puberty (9-14 years), and boys later in puberty (14-16 years). Many factors may affect growth in children, and some of these are noted in Table 1. This article concentrates on the role of growth hormone. The hypothalamus produces growth hor mone releasing hormone (GHRH), which acts on the anterior pituitary. Growth hormone is then produced mainly from somatroph cells located in the lateral wings. This release is reg ulated by two mechanisms: • Growth hormone releasing hormone (GHRH). This is the positive releasing factor and is stimulated by sleep, exercise, physical and emo tional stress, increased protein intake and hypoglycaemia
Table 1. Factors that may affect growth in children.
Genetic: Chromosomal - abnormalities associated with short stature Environmental: Nutrition - adequate, healthy diet is required for normal growth Emotional: For example, secure home background is essential for normal growth Seasons: Rate of growth varies throughout the year Exercise: Long periods of inactivity are restrictive to bone growth Endocrine: Thyroid (promotes growth and maturation of connective tissues, bone, teeth and brain), insulin, sex hormones, growth hormone. August 19/Volunie 6/Number 48/1992 Nursing Standard 33
CLINICAL
l
'AA
Each child is measured on arrival in the clinic using a Ilarpenden Stadiometer.
PAEDIATRICS
• Growth hormone release inhibiting hormone (somatostatin). This is stimulated by rapid eye movement (REM) sleep, psychogenic factors, malnutrition, central nervous system or pituitary trauma, perinatal insults or pharma cological agents. There are two main actions of growth hormone: • Growth promotion (skeletal and tissue) • Metabolism (fat and carbohydrate) (Fig.l). It can therefore be seen that growth hormone has an important role to play in regulating the growth and health of children, and that defi ciency can lead to growth failure. Short stature There are many causes of short stature in children, but they can be divided into five groups: • Familial short stature, that is, normal but short parents • Constitutional delay of growth and puberty • Congenital conditions, such as skeletal dysplasia • Chronic organic or emotional systemic dis orders, for example dietary insufficiency, renal failure, psychosocial deprivation • Endocrine abnormalities, such as growth hormone deficiency. The most useful tools in the assessment of short stature in the slowly growing child arcgrowth charts and the correct measuring equipment and technique. Growth charts show the normal range of centiles tor growth of children aged 1 to 19 years. There are sep arate charts for boys and girls. Any child who falls below the third centile ( bottom line) or who is growing slowly should be referred to a specialist, as should those children who seem inappropriately short considering the height of their parents. Administration of growth hormone has
Two children in the sleep laboratory. Blood samples are taken via the hatch in the wall to avoid disturbing the children. Urine collecting containers are at the bedside.
%
w .
34 Nursing Standard August 19/Volume 6/Number 48/1992
•
Table 2. Research protocols. Group A. Boys and girls less than 10 years old with familial short stature and no growth delay . This is a double blind trial, the treatment con sisting of: growth hormone or placebo for one year, then growth hormone, or two years with no treat ment then growth hormone Group B. Prepubertal boys (less than 14 years) with no growth delay. The treatment consists of: growth hormone or oxandralone (anabolic steroid), or growth hormone and oxandralone, or no treatment for one year then growth hormone Group C. Pre or early puberty boys (more than 14 years). The treatment consists of: growth hormone, or testosterone, or growth hormone and testosterone been proven to be effective in children with growth hormone deficiency and other dis orders such as Turner’s syndrome. Recent controversy has highlighted the risk of adults developing Creutzfeldt-Jakob dis ease (CJD) following administration of human growth hormone as children (1,2). Before 1985, growth hormone was harvested from human cadavers and it is this substance which appears to be implicated in transmitting CJD. Since 1985, the human substance has been replaced by genetically engineered hormone. In Edinburgh, a clinical research trial has been set up to investigate whether growth hor mone has a role to play in the treatment of short normal children, that is, those with familial short stature and constitutional delay of growth and puberty. The ongoing trials are comparing the effect of administering growth hormone with ana bolic and sex steroids singly or in
CLINICAL
Table 3. A guide to accurate measurement. In order ro measure a child accurately, a number of rules should be followed: 1. Remove the child’s shoes and socks. Loose or baggy socks may disguise the fact that a child's heels are lifting off the ground. 2. The child should stand with heels together, legs straight and shoulders relaxed. 3. Heels, buttocks and, if possible, scapulae should be against the wall. 4. Place the headboard on the top of the head and check that the head is in the correct position. The child should look straight ahead with the lower margins of the eyes in the same horizon tal plane as the external auditory meati. 5. Tell the child to ‘breathe in and stand tali’. Apply gentle but firm pressure to the mastoid processes to help the child stretch. Ensure the heels are not lifted from the ground. 6. Tell the child to ‘breathe out and relax’ while the measure maintains pressure on the head. 7. Read the height to the last complete millimetre (do not round up). 8. Plot the height reading on a standard centile chart of height for age and sex.
PAEDIATRICS
combination. A placebo group was also estab lished. The children we were interested in investigating were of various ages, so three protocols were set up (Table 2). Children admitted to one of the protocols underwent: • Assessment of endogenous growth hormone secretion, involving overnight sleep studies, 24-hour urine collection and an insulin toler ance test • Anthropometry, with regular three-month ly visits to the clinic for measuring • Psychological assessment, involving filling in questionnaires to assess behaviour, anxiety and depression status and self concept, family and school assessment and intelligence/ academic tests. Recruitment for the trial took place in the clinic in the outpatient department.
Clinic visit Each child is measured on arrival, standing and sitting, using the Harpender Stadiometer. Measurements are carried out by the same per son at each clinic visit, if possible. The parents are also measured and their heights recorded, as are those of any siblings present. Correct technique must be applied to get accurate results (Table 3). During the initial interview, all the rele vant history is obtained. The child is examined to see if there are any abnormalities, such as the widely spaced nipples commonly found in girls with Turner’s syndrome. The child’s cardiac and gastrointestinal sta tus are checked, and his or her optic disc margins are examined to ensure that the intracranial pressure is not raised, an indica tion of possible intracerebral tumour. Pubertal status is also assessed. During this initial meeting, it may some times be necessary to take a blood sample for some baseline investigations, for example thy roid function tests, and to establish the chromosome karyotype. We also obtain an X-ray of the child’s left hand to assess the bone maturity development. The reason for this is that some short children may simply have ‘used up’ a smaller propor tion of their growth than their peers. A scale is used to measure bone maturity against chronological age: a child with growth delay will show a bone maturity less than the chronological age. On subsequent visits at three-monthly intervals, accurate measurement is carried out and the growth velocity is established to assess if the child is growing appropriately or not. Children with familial short stature and
constitutional delay of growth and puberty who were having problems because of their size were then informed of the ongoing trials. The next stage was to investigate further with overnight profile and an insulin tolerance test. Overnight sleep study This involves the child coming into hospital one evening and staying the night, with blood samples being taken during the night through a cannula. Two patients usually arrive at the sleep laboratory at 6.30pm. The laboratory consists of one room, with two beds, which is connected to another room by a hatch in the wall, allowing blood sam pling without entering the room and disturbing the patients. Before the procedure begins, we explain once again what will happen. Local anaesthetic cream is applied over potential intravenous access sites. While the cream takes effect, the children are examined to make sure they are fit and well. A variety of games and a TV are in the room for the children’s entertainment. It is important to know to what extent chil dren suffer emotionally because of short stature and whether treatment that makes them grow is of psychological benefit. In older children we are looking at the psychological aspects of being small and we use this time to ask whether the children and their parents will complete questionnaires to help us measure possible psychological effects of short stature. Intravenous cannulae are inserted and a ban dage is applied to the well-secured cannula to keep the arm straight. Blood sampling starts at 8pm and continues every 10 or 20 minutes, adjusted according to the size of the child. The children are usually settled in bed by 10pm. The long line attached to the cannula allows the tube to pass through the hatch and leave enough room for the child to move around in the bed. During the test, we also collect the child’s urine so that growth hormone con tained in it can be measured and the results compared with blood levels. Sensitive urinary growth hormone assays could be a useful way of screening short children in the future. In the morning, an insulin hypoglycaemia test and tests of pituitary function are per formed, looking at the thyroid and gonadal axis. All the children recruited into the trial have had an insulin tolerance test to ensure there are no abnormalities with their growth hormone production. This involves giving the child insulin and dropping the blood glucose, stimulating growth hormone release. The child must be very closely observed during this test as it is potentially dangerous. A nurse and preferably a doctor must be pre sent for the first hour and a half while the child August 19/Volume 6/Number 48/1992 Nursing Standard 35
CLINICAL PAEDIATRICS
X-ray of left hand of boy, showing bone maturity of 11.5 years. This corresponded with his chronological age.
is hypoglycaemic. Dextrose 50 per cent and hydrocortisone 1 OOmg must be at hand in case the child collapses because of the effects of hypoglycaemia. After administration of the insulin, blood samples are taken after the first minute, and also after 20, 30, 60, 90, 120 and 150 min utes. Half an hour after the insulin is given the child will show various signs of hypogly caemia and may be sleepy, pale, sweating and irritable. 1 le or she must be kept awake to assess the conscious level and if the child falls into unconsciousness, resuscitativc measures must be taken. This is not common, however; over the past two years we have not had to resort to this response.
Potentially dangerous
References 1. Dyer C. Hormone evidence grew bur penny didn't drop. The Guardian. 1992. July 6,2. 2. Dyer C. Growth aid was refused licence. The Guardian. 1992. July 27, 2. further reading Lewis J G. The Endocrine System. Edinburgh, Churchill Livingstone. 1984. Hughes L.A. Handbook of Endocrine Tests in Children. Bristol, Wright. 1986. Kelnar C J. Pride & prejudice stature in perspective. Acta Paediatr Scand. 1990. 370, suppl, 5-15. Kelnar C J . Growth. Medicine International. 1989- 64, 26.32-2638.
Once the test is finished the children are given breakfast and are usually allowed home two to three hours after the test is completed. The parents are asked to give them regular meals throughout the day. It must be stressed that this test should only be done in specialised centres as it is potentially very dangerous. The results of the tests are then analysed in terms of the amount of growth hormone secreted. A child who produces normal amounts of growth hormone will produce three to four ‘pulses’ of growth hormone dur ing the night. Those who are deficient show small or no pulses. Following insulin hypo glycaemia, if the level of growth hormone reaches more than 15mU/L, the child is not deficient. Severe insufficiency is indicated by a level less than 7mU/L. Children with normal test results are then entered into the trial once informed consent
36 Nursing Standard August 19 Volume 6. Number 48/1992
has been obtained from them and their par ents. This involves a visit to the ward, prefer ably with both parents. They are given infor mation sheets and time to decide whether they think entry into the trial is appropriate. Most parents have decided positively before coming to the clinic and the interview is used to air any worries or questions still unanswered. The child is then allocated randomly into a specific treatment group of the appropriate protocol. The child picks one of a handful of numbered cards, the code is read and he or she is informed what the treatment is to be. If the child is allocated to the growth hor mone treatment group, the home care team is involved. A district nurse will visit the child at home and demonstrate how to carry out the injections and teach the correct method for disposal of needles and syringes. After a few visits the parents or, in most cases, the children are capable of carrying out the injection without supervision from the nurse. The family know they can contact the hospital, nurse or doctor at any time if they have problems. During the trial, follow-up is of great importance. Every three months the child returns to the clinic and accurate measure ments and tests are undertaken to ensure he or she is experiencing no adverse effects. We know from adults who produce excess growth hormone that they can develop high blood pressure and diabetes, so the child’s blood pressure is checked, and the blood is analysed for glucose levels, glycosylated haemoglobin and other biochemical measurements. Recruitment for the trial is almost complete and we now have to wait for results while maintaining careful follow-up. Some interest ing questions have already arisen, however. For example, are we only stimulating growth in the short to medium term, thus achieving predicted adult height sooner? Is it ethical to give growth hormone by daily injections in a child who is ‘normal’ in physical aspects but not functioning normally psychologically, as we have found in many of these children? We hope to answer these questions and oth ers related to growth and psychological assessment. It certainly seems that a child’s morale can improve dramatically with growth promoting treatment. Many of the children are pleased that something is being tried and those receiving growth hormone find the daily injections by no means as daunting as they had expected. Meanwhile, we must continue with careful observation and recording of data and results before the success of growth promot ing treatment in these children can be properly assessed.
PAEDIATRICS
Evaluating growth hormone treatment Barbara Wardhaugh RGN, RSCN. is Research Staff Nurse, Royal Hospital for Sick Children, Edinburgh.
The consequences in later lifefor people whose growth in childhood has been restricted can be profound, often with severe emotional or psychological effects. The author defines the causes of short stature and describes clinical trials being undertaken to evaluate the use of growth hormone in children who do not appear to have growth hormone deficiency.
Disturbing prejudices against people who are short in stature continue to exist: such people may be regarded with contempt, treated as being younger than their years at school and work, and called various derisory nicknames. Children and adults who form the focus of these kinds of attacks may be profoundly affected by them. They may feel that they are not taken seriously by their peers, and are con sidered incapable of doing certain jobs or of being suitable candidates for promotion in the workplace. I have become aware of this prejudice in my work as a research nurse looking into growth in children and the use of growth hormone. This article offers a summary of normal growth in children and the causes of short stature, but concentrates on current clinical research trials on the treatment of children who do not have growth hormone deficiency but who are nev ertheless of short stature - so-called ‘short normal children’. Growth starts at the moment of conception from a single cell, and continues rapidly in the months up to birth. Thereafter, growth can be summarised as having three distinct phases: • There is a period of fast growth during infan cy, although this represents the continuation of deceleration in growth that started after a peak in utero at seven months • There follows a slow decline in rateofgrowth during the prepubertal years (2-10 years),
Fig. 1. Growth promotion and metabolism Hypothalamus releases IRH
GHRIH (somatostatin)
"x Anterior pituitary Growth hormone
^ Growth promotion
Skeletal
Extra-skeletal
^x Intermediary metabolism
y \
Fat
Carbohydrate
although the child usually grows between five and six centimetres per year during this time • The final phase depends on the sex of the child. Girls have their growth spurt at the beginning of puberty (9-14 years), and boys later in puberty (14-16 years). Many factors may affect growth in children, and some of these are noted in Table 1. This article concentrates on the role of growth hormone. The hypothalamus produces growth hor mone releasing hormone (GHRH), which acts on the anterior pituitary. Growth hormone is then produced mainly from somatroph cells located in the lateral wings. This release is reg ulated by two mechanisms: • Growth hormone releasing hormone (GHRH). This is the positive releasing factor and is stimulated by sleep, exercise, physical and emo tional stress, increased protein intake and hypoglycaemia
Table 1. Factors that may affect growth in children.
Genetic: Chromosomal - abnormalities associated with short stature Environmental: Nutrition - adequate, healthy diet is required for normal growth Emotional: For example, secure home background is essential for normal growth Seasons: Rate of growth varies throughout the year Exercise: Long periods of inactivity are restrictive to bone growth Endocrine: Thyroid (promotes growth and maturation of connective tissues, bone, teeth and brain), insulin, sex hormones, growth hormone. August 19/Volunie 6/Number 48/1992 Nursing Standard 33
CLINICAL
l
'AA
Each child is measured on arrival in the clinic using a Ilarpenden Stadiometer.
PAEDIATRICS
• Growth hormone release inhibiting hormone (somatostatin). This is stimulated by rapid eye movement (REM) sleep, psychogenic factors, malnutrition, central nervous system or pituitary trauma, perinatal insults or pharma cological agents. There are two main actions of growth hormone: • Growth promotion (skeletal and tissue) • Metabolism (fat and carbohydrate) (Fig.l). It can therefore be seen that growth hormone has an important role to play in regulating the growth and health of children, and that defi ciency can lead to growth failure. Short stature There are many causes of short stature in children, but they can be divided into five groups: • Familial short stature, that is, normal but short parents • Constitutional delay of growth and puberty • Congenital conditions, such as skeletal dysplasia • Chronic organic or emotional systemic dis orders, for example dietary insufficiency, renal failure, psychosocial deprivation • Endocrine abnormalities, such as growth hormone deficiency. The most useful tools in the assessment of short stature in the slowly growing child arcgrowth charts and the correct measuring equipment and technique. Growth charts show the normal range of centiles tor growth of children aged 1 to 19 years. There are sep arate charts for boys and girls. Any child who falls below the third centile ( bottom line) or who is growing slowly should be referred to a specialist, as should those children who seem inappropriately short considering the height of their parents. Administration of growth hormone has
Two children in the sleep laboratory. Blood samples are taken via the hatch in the wall to avoid disturbing the children. Urine collecting containers are at the bedside.
%
w .
34 Nursing Standard August 19/Volume 6/Number 48/1992
•
Table 2. Research protocols. Group A. Boys and girls less than 10 years old with familial short stature and no growth delay . This is a double blind trial, the treatment con sisting of: growth hormone or placebo for one year, then growth hormone, or two years with no treat ment then growth hormone Group B. Prepubertal boys (less than 14 years) with no growth delay. The treatment consists of: growth hormone or oxandralone (anabolic steroid), or growth hormone and oxandralone, or no treatment for one year then growth hormone Group C. Pre or early puberty boys (more than 14 years). The treatment consists of: growth hormone, or testosterone, or growth hormone and testosterone been proven to be effective in children with growth hormone deficiency and other dis orders such as Turner’s syndrome. Recent controversy has highlighted the risk of adults developing Creutzfeldt-Jakob dis ease (CJD) following administration of human growth hormone as children (1,2). Before 1985, growth hormone was harvested from human cadavers and it is this substance which appears to be implicated in transmitting CJD. Since 1985, the human substance has been replaced by genetically engineered hormone. In Edinburgh, a clinical research trial has been set up to investigate whether growth hor mone has a role to play in the treatment of short normal children, that is, those with familial short stature and constitutional delay of growth and puberty. The ongoing trials are comparing the effect of administering growth hormone with ana bolic and sex steroids singly or in
CLINICAL
Table 3. A guide to accurate measurement. In order ro measure a child accurately, a number of rules should be followed: 1. Remove the child’s shoes and socks. Loose or baggy socks may disguise the fact that a child's heels are lifting off the ground. 2. The child should stand with heels together, legs straight and shoulders relaxed. 3. Heels, buttocks and, if possible, scapulae should be against the wall. 4. Place the headboard on the top of the head and check that the head is in the correct position. The child should look straight ahead with the lower margins of the eyes in the same horizon tal plane as the external auditory meati. 5. Tell the child to ‘breathe in and stand tali’. Apply gentle but firm pressure to the mastoid processes to help the child stretch. Ensure the heels are not lifted from the ground. 6. Tell the child to ‘breathe out and relax’ while the measure maintains pressure on the head. 7. Read the height to the last complete millimetre (do not round up). 8. Plot the height reading on a standard centile chart of height for age and sex.
PAEDIATRICS
combination. A placebo group was also estab lished. The children we were interested in investigating were of various ages, so three protocols were set up (Table 2). Children admitted to one of the protocols underwent: • Assessment of endogenous growth hormone secretion, involving overnight sleep studies, 24-hour urine collection and an insulin toler ance test • Anthropometry, with regular three-month ly visits to the clinic for measuring • Psychological assessment, involving filling in questionnaires to assess behaviour, anxiety and depression status and self concept, family and school assessment and intelligence/ academic tests. Recruitment for the trial took place in the clinic in the outpatient department.
Clinic visit Each child is measured on arrival, standing and sitting, using the Harpender Stadiometer. Measurements are carried out by the same per son at each clinic visit, if possible. The parents are also measured and their heights recorded, as are those of any siblings present. Correct technique must be applied to get accurate results (Table 3). During the initial interview, all the rele vant history is obtained. The child is examined to see if there are any abnormalities, such as the widely spaced nipples commonly found in girls with Turner’s syndrome. The child’s cardiac and gastrointestinal sta tus are checked, and his or her optic disc margins are examined to ensure that the intracranial pressure is not raised, an indica tion of possible intracerebral tumour. Pubertal status is also assessed. During this initial meeting, it may some times be necessary to take a blood sample for some baseline investigations, for example thy roid function tests, and to establish the chromosome karyotype. We also obtain an X-ray of the child’s left hand to assess the bone maturity development. The reason for this is that some short children may simply have ‘used up’ a smaller propor tion of their growth than their peers. A scale is used to measure bone maturity against chronological age: a child with growth delay will show a bone maturity less than the chronological age. On subsequent visits at three-monthly intervals, accurate measurement is carried out and the growth velocity is established to assess if the child is growing appropriately or not. Children with familial short stature and
constitutional delay of growth and puberty who were having problems because of their size were then informed of the ongoing trials. The next stage was to investigate further with overnight profile and an insulin tolerance test. Overnight sleep study This involves the child coming into hospital one evening and staying the night, with blood samples being taken during the night through a cannula. Two patients usually arrive at the sleep laboratory at 6.30pm. The laboratory consists of one room, with two beds, which is connected to another room by a hatch in the wall, allowing blood sam pling without entering the room and disturbing the patients. Before the procedure begins, we explain once again what will happen. Local anaesthetic cream is applied over potential intravenous access sites. While the cream takes effect, the children are examined to make sure they are fit and well. A variety of games and a TV are in the room for the children’s entertainment. It is important to know to what extent chil dren suffer emotionally because of short stature and whether treatment that makes them grow is of psychological benefit. In older children we are looking at the psychological aspects of being small and we use this time to ask whether the children and their parents will complete questionnaires to help us measure possible psychological effects of short stature. Intravenous cannulae are inserted and a ban dage is applied to the well-secured cannula to keep the arm straight. Blood sampling starts at 8pm and continues every 10 or 20 minutes, adjusted according to the size of the child. The children are usually settled in bed by 10pm. The long line attached to the cannula allows the tube to pass through the hatch and leave enough room for the child to move around in the bed. During the test, we also collect the child’s urine so that growth hormone con tained in it can be measured and the results compared with blood levels. Sensitive urinary growth hormone assays could be a useful way of screening short children in the future. In the morning, an insulin hypoglycaemia test and tests of pituitary function are per formed, looking at the thyroid and gonadal axis. All the children recruited into the trial have had an insulin tolerance test to ensure there are no abnormalities with their growth hormone production. This involves giving the child insulin and dropping the blood glucose, stimulating growth hormone release. The child must be very closely observed during this test as it is potentially dangerous. A nurse and preferably a doctor must be pre sent for the first hour and a half while the child August 19/Volume 6/Number 48/1992 Nursing Standard 35
CLINICAL PAEDIATRICS
X-ray of left hand of boy, showing bone maturity of 11.5 years. This corresponded with his chronological age.
is hypoglycaemic. Dextrose 50 per cent and hydrocortisone 1 OOmg must be at hand in case the child collapses because of the effects of hypoglycaemia. After administration of the insulin, blood samples are taken after the first minute, and also after 20, 30, 60, 90, 120 and 150 min utes. Half an hour after the insulin is given the child will show various signs of hypogly caemia and may be sleepy, pale, sweating and irritable. 1 le or she must be kept awake to assess the conscious level and if the child falls into unconsciousness, resuscitativc measures must be taken. This is not common, however; over the past two years we have not had to resort to this response.
Potentially dangerous
References 1. Dyer C. Hormone evidence grew bur penny didn't drop. The Guardian. 1992. July 6,2. 2. Dyer C. Growth aid was refused licence. The Guardian. 1992. July 27, 2. further reading Lewis J G. The Endocrine System. Edinburgh, Churchill Livingstone. 1984. Hughes L.A. Handbook of Endocrine Tests in Children. Bristol, Wright. 1986. Kelnar C J. Pride & prejudice stature in perspective. Acta Paediatr Scand. 1990. 370, suppl, 5-15. Kelnar C J . Growth. Medicine International. 1989- 64, 26.32-2638.
Once the test is finished the children are given breakfast and are usually allowed home two to three hours after the test is completed. The parents are asked to give them regular meals throughout the day. It must be stressed that this test should only be done in specialised centres as it is potentially very dangerous. The results of the tests are then analysed in terms of the amount of growth hormone secreted. A child who produces normal amounts of growth hormone will produce three to four ‘pulses’ of growth hormone dur ing the night. Those who are deficient show small or no pulses. Following insulin hypo glycaemia, if the level of growth hormone reaches more than 15mU/L, the child is not deficient. Severe insufficiency is indicated by a level less than 7mU/L. Children with normal test results are then entered into the trial once informed consent
36 Nursing Standard August 19 Volume 6. Number 48/1992
has been obtained from them and their par ents. This involves a visit to the ward, prefer ably with both parents. They are given infor mation sheets and time to decide whether they think entry into the trial is appropriate. Most parents have decided positively before coming to the clinic and the interview is used to air any worries or questions still unanswered. The child is then allocated randomly into a specific treatment group of the appropriate protocol. The child picks one of a handful of numbered cards, the code is read and he or she is informed what the treatment is to be. If the child is allocated to the growth hor mone treatment group, the home care team is involved. A district nurse will visit the child at home and demonstrate how to carry out the injections and teach the correct method for disposal of needles and syringes. After a few visits the parents or, in most cases, the children are capable of carrying out the injection without supervision from the nurse. The family know they can contact the hospital, nurse or doctor at any time if they have problems. During the trial, follow-up is of great importance. Every three months the child returns to the clinic and accurate measure ments and tests are undertaken to ensure he or she is experiencing no adverse effects. We know from adults who produce excess growth hormone that they can develop high blood pressure and diabetes, so the child’s blood pressure is checked, and the blood is analysed for glucose levels, glycosylated haemoglobin and other biochemical measurements. Recruitment for the trial is almost complete and we now have to wait for results while maintaining careful follow-up. Some interest ing questions have already arisen, however. For example, are we only stimulating growth in the short to medium term, thus achieving predicted adult height sooner? Is it ethical to give growth hormone by daily injections in a child who is ‘normal’ in physical aspects but not functioning normally psychologically, as we have found in many of these children? We hope to answer these questions and oth ers related to growth and psychological assessment. It certainly seems that a child’s morale can improve dramatically with growth promoting treatment. Many of the children are pleased that something is being tried and those receiving growth hormone find the daily injections by no means as daunting as they had expected. Meanwhile, we must continue with careful observation and recording of data and results before the success of growth promot ing treatment in these children can be properly assessed.
