Physiological controversies and methods used to determine fluid responsiveness: a qualitative systematic review.

Accurate assessment of intravascular fluid status and measurement of fluid responsiveness have become increasingly important in peri-operative medicine and critical care. The objectives of this systematic review and narrative synthesis were to discuss current controversies surrounding fluid responsiveness and describe the merits and limitations of the major cardiac output monitors in clinical use today in terms of usefulness in measuring fluid responsiveness. We searched the MEDLINE and EMBASE databases (2002-2015); inclusion criteria included comparison with an established reference standard such as pulmonary artery catheter, transthoracic echocardiography and transoesophageal echocardiography. Examples of clinical measures include static (such as central venous pressure) and dynamic (such as stroke volume variation and pulse pressure variation) parameters. The static parameters measured were described as having little value; however, the dynamic parameters were shown to be good physiological determinants of fluid responsiveness. Due to heterogeneity of the methods and patient characteristics, we did not perform a meta-analysis. In most studies, precision and limits of agreement (bias ±1.96SD) between determinants of fluid responsiveness measured by different devices were not evaluated, and the definition of fluid responsiveness varied across studies. Future research should focus on the physiological principles that underlie the measurement of fluid responsiveness and the effect of different volume expansion strategies on outcomes.

Growth parameters and endocrine function in relation to echocardiographic parameters in children with ventricular septal defect without heart failure.

To determine the effect of ventricular function, size of ventricular septal defect (VSD), and endocrine function on linear growth in children with VSD, we studied 88 children with VSD over a period of 1 year. Growth was assessed by determining the height standard deviation scores (HtSDS) and growth velocity (GV) every 4 months. Two hundred age-matched normal children served as controls for the growth data. Endocrine evaluation was performed in 30 randomly selected children with VSD, and 20 age-matched children with constitutional delay of growth (CSS). Growth hormone (GH) response to clonidine provocation was evaluated and circulating free thyroxine (FT4) and insulin-like growth factor-I (IGF-I) concentrations measured. Echocardiographic evaluation of the different cardiac parameters including shunt size and shunt fraction (Qp/Qs) was performed using a colour-coded echodoppler. The HtSDS, body mass index (BMI), and mid-arm circumference (MAC) of children with VSD were significantly decreased compared to those for the normal control group. The dietary intake evaluated by the recall method, appeared to be adequate in the majority of these children (83/88). IGF-I concentrations were reduced in children with VSD (87.5 +/- 29 ng/ml) versus normal age-matched children (169 +/- 42 ng/ml). Basal and clonidine-stimulated GH concentrations were significantly higher in children with VSD (4.6 +/- 2.1 microg/l and 28.8 +/- 7.9 microg/l respectively) versus controls (17.8 +/- 4.2 microg/l). In these patients (n = 88) the HtSDS was correlated negatively with the size of the shunt (r = -0.793, p < 0.001), shunt fraction (Qp/Qs) (r = -0.76, p < 0.001), pulmonary mean gradient (r = -0.4, p = 0.006), and pulmonary maximum velocity (r = -0.32, p = 0.02). Growth velocity (GV) was correlated negatively with pulmonary maximum gradient (r = -0.3, p = 0.02), pulmonary maximum velocity (r = -0.37, p = 0.007), and pulmonary stroke volume (Qp) (r = -0.345, p = 0.01). The BMI and IGF-I concentrations were correlated significantly with the size of the shunt (r = -0.453, p < 0.01), Qp/Qs (r = -0.432, p < 0.01), HtSDS (r = 0.565, p < 0.01), and BMI (r = 0.435, p < 0.01). It appears that in patients with VSD, the size of the left-to-right shunt and the abnormal hemodynamics in the pulmonary circulation are important factors in the etiology of impaired growth. It is suggested that the hypermetabolic status of these patients compromise nutrition and this decreases IGF-I synthesis with subsequent slowing of linear growth and weight gain.

Serum leptin concentrations during severe protein-energy malnutrition: correlation with growth parameters and endocrine function.

Circulating leptin, insulin, insulin-like growth factor-I (IGF-I), cortisol, and albumin concentrations and the growth hormone (GH) response to provocation were measured in 30 children with severe protein-energy malnutrition (PEM), 20 with marasmus and 10 with kwashiorkor, as well as 10 age-matched normal children (body mass index [BMI] >50th and <90th percentile for age and sex) and 10 prepubertal obese children (BMI >95th percentile for age and sex). Patients with PEM had a significantly lower BMI, midarm circumference (MAC), and skinfold thickness (SFT) compared with the age-matched control group. Basal cortisol and GH concentrations were significantly higher in the malnourished groups versus controls. Leptin and IGF-I were significantly lower in the marasmic and kwashiorkor groups versus normal children. Fasting insulin levels were significantly decreased in the kwashiorkor group compared with marasmic and normal children. The BMI correlated significantly with leptin (r = .77, P < .001), basal insulin (r = .61, P < .001), and IGF-I (r = .77, P < .001) and negatively with basal GH (r = -.52, P < .001). These findings suggest that during prolonged nutritional deprivation, the decreased energy intake, diminished subcutaneous fat mass, and declining insulin (and possibly IGF-I) concentration suppress leptin production. In support of this view, serum leptin levels were positively correlated with triceps, scapular, and abdominal SFT (r = .763, .75, and .744, respectively, P < .0001) in all of the children. Moreover, basal insulin and circulating IGF-I were correlated significantly with leptin concentrations (r = .47 and .62, respectively, P < .001). Basal levels of cortisol and GH were significantly elevated in the 2 groups with severe PEM. It is suggested that low leptin levels can stimulate the hypothalamic-pituitary-adrenal (HPA) axis and possibly the hypothalamic-pituitary-GH axis to maintain the high cortisol and GH levels necessary for effective lipolysis to ensure a fuel (fatty acids) supply for the metabolism of brain and peripheral tissue during nutritional deprivation. In summary, during prolonged PEM, the decreased synthesis of IGF-I and the low level of insulin and/or its diminished effect due to an insulin-resistant status in the presence of high circulating GH and cortisol levels ensure substrate diversion away from growth toward metabolic homeostasis. Leptin appears to be an important signal in the process of metabolic/endocrine adaptation to prolonged nutritional deprivation.

Spontaneous and GnRH-provoked gonadotropin secretion and testosterone response to human chorionic gonadotropin in adolescent boys with thalassaemia major and delayed puberty.

To elucidate whether the cause of sexual maturation arrest in thalassaemia is of gonadal or pituitary etiology, 10 males with thalassaemia and delayed puberty and 10 with constitutional delay of growth and pubertal maturation (CSS) were extensively studied. Their spontaneous nocturnal gonadotropin secretion and gonadotropin response to intravenous 100 micrograms gonadotropin-releasing hormone (GnRH) were evaluated. Circulating testosterone concentration and clinical response were evaluated after 3 days, 4 weeks and 6 months of intramuscular administration of human chorionic gonadotropin (HCG) (2500 U/m2/dose). Thalassaemic boys had significantly lower circulating concentrations of testosterone compared to those with constitutional delay of growth and sexual maturation (CSS) at the same pubertal stage. Short- and long-term testosterone response to administrations of HCG was markedly decreased in thalassaemic boys. After 6 months of HCG administration 50 per cent (5/10) of the boys did not show significant testicular enlargement or genital changes. Despite the low circulating concentrations of testosterone, none of the patients had high basal or exaggerated gonadotropin response to gonadotropin releasing hormone (GnRH) stimulation. Luteinizing hormone (LH) peak responses to GnRH were significantly lower as compared to controls. Follicle-stimulating hormone (FSH) peak responses to GnRH did not differ among the two study groups. The mean nocturnal LH and FSH secretion was significantly decreased in all thalassaemic boys as compared to boys with CSS at the same pubertal stage (testicular volume). These data proved that hypogonadotropic hypogonadism is the main cause of delayed/failed puberty in adolescents with thalassaemia major. MRI studies revealed complete empty sella (n = 5), marked diminution of the pituitary size (n = 5), thinning of the pituitary stalk (n = 3) with its posterior displacement (n = 2), and evidence of iron deposition in the pituitary gland and midbrain (n = 8) in thalassaemic patients, denoting a high incidence of structural abnormalities (atrophy) of the pituitary gland. Moreover, in many of the thalassaemic boys, the defective testosterone response to long-term (6 months) HCG therapy denoted significant testicular atrophy and/or failure secondary to siderosis. It appears that testosterone replacement might be superior to HCG therapy in these patients. This therapy should be introduced at the proper time in these hypogonadal patients to induce their sexual development and to support their linear growth spurt and bone mineral accretion.

Growth and pubertal development in transfusion-dependent children and adolescents with thalassaemia major and sickle cell disease: a comparative study.

Despite regular blood transfusion and desferrioxamine treatment, growth impairment and pubertal delay are commonly seen in children and adolescents with transfusion-dependent thalassaemia and sickle cell disease (SCD). We evaluated growth parameters and sexual maturation in a large cohort of children and adolescents with SCD (n = 110) and thalassaemia (n = 72) receiving nearly the same protocol of transfusion and chelation, and compared them with those for 200 normal age-matched children, 30 children with constitutional delay of growth (CSS), and 25 children with growth hormone deficiency (GHD). Before transfusion, haemoglobin concentration had not been less than 9 g/dl in the past 7 years; desferrioxamine was administered for 7-10 years, including by the intramuscular and subcutaneous routes, three times or more per week. The height standard deviation score (HtSDS), growth velocity (GV) (cm/yr), and growth velocity standard deviation score (GVDSD) of children and adolescents with thalassaemia and SCD were significantly decreased compared to normal children (p < 0.01). Forty-nine per cent of thalassaemic patients and 27 per cent of patients with SCD had HtSDS less than -2, and 83 per cent of thalassaemic patients and 67 per cent of SCD patients had HtSDS less than -1. Fifty-six per cent of thalassaemic children and 51 per cent of children with SCD had GVSDS less than -1. The GV of thalassaemic children was significantly slower than that for children with SCD. Children with thalassaemia and SCD had HtSDS and GVSDS comparable to those for children with CSS but higher than those for patients with GHD. Serum ferritin concentration was correlated significantly with the linear GV in all patients (r = 0.45, p < 0.001). The bone age delay did not differ among the three groups with thalassaemia, SCD and CSS, but the delay was significant in the group with GHD. The mid-arm circumference was significantly smaller in children with thalassaemia and SCD than in normal children. The triceps skin-fold thickness of patients with SCD was significantly decreased compared to thalassaemic and normal children. The upper/lower segment ratio was significantly lower in thalassaemic and SCD patients than in normal children. In thalassaemic patients between the ages of 13 and 21 years a complete lack of pubescent changes was present in 73 per cent of boys and 42 per cent of girls. Seventy-four per cent of the thalassaemic girls had primary amenorrhoea. Girls with SCD aged between 13 and 21 years had markedly delayed breast development and menarche. Twenty-five per cent of boys with SCD above the age of 14 years had absence of testicular development. Males with thalassaemia and SCD who had spontaneous testicular development had significantly smaller testicular volume than did normal controls. Short children with thalassaemia and SCD had significantly decreased serum insulin-like growth factor 1 (IGF-1) concentrations compared to children with CSS. Collectively, these data confirm the high prevalence of impaired growth and pubertal delay/failure in children and adolescents with thalassaemia and SCD. The aetiology of impaired growth includes the contributions of lack of pubertal growth spurt due to delayed/absent puberty, decreased synthesis of IGF-1 which might be secondary to a disturbed GH-IGF-1 axis and/or under nutrition, probably due to the hypermetabolic status of these children. It is suggested that newer protocols of treatment, in addition to optimization of transfusion and chelation requirements, should increase the caloric intake of these patients and properly manage their pubertal delay-failure in order to improve their adult height.

Spontaneous and provoked growth hormone (GH) secretion and insulin-like growth factor I (IGF-I) concentration in patients with beta thalassaemia and delayed growth.

Growth retardation in children with thalassaemia major is multifactorial. We studied the growth hormone (GH) response to provocation by clonidine and glucagon, measured the circulating concentrations of insulin, insulin-like growth factor-I (IGF-I), IGF-binding protein-3 (IGFBP3), and ferritin, and evaluated the spontaneous nocturnal (12 h) GH secretion in prepubertal patients with thalassaemia and age-matched children with constitutional short stature (CSS) (height SDS < -2, but normal GH response to provocation). The anatomy of the hypothalamic pituitary area was studied in patients with abnormal GH secretion using MRI scanning. Children with thalassaemia had significantly lower peak GH response to provocation by clonidine and glucagon (8.8 +/- 2.3 micrograms/l and 8.2 +/- 3.1 micrograms/l respectively) than did controls (17.6 +/- 2.7 micrograms/l and 15.7 +/- 3.7 micrograms/l respectively). They had significantly decreased circulating concentrations of IGF-I and IGFBP3 (68.5 +/- 19 ng/ml and 1.22 +/- 0.27 mg/l respectively) compared to controls (153 +/- 42 ng/ml and 2.16 +/- 0.37 mg/l respectively). Seven of the thalassaemic children had a GH peak response of < 7 micrograms/l after provocation. Those with a normal GH response after provocation also had significantly lower IGF-I and IGFBP3 concentrations than controls. Analysis of their spontaneous nocturnal GH secretion revealed lower mean (2.9 +/- 1.77 micrograms/l) and integrated (2.53 +/- 1.6 micrograms/l) concentrations compared to controls (4.9 +/- 0.29 micrograms/l and 5.6 +/- 0.52 micrograms/l respectively). Five of them had mean nocturnal GH concentration < 2 micrograms/l and four had maximum nocturnal peak below 10 micrograms/l. These data denoted defective spontaneous GH secretion in some of these patients. MRI studies revealed complete empty sella (n = 2), marked diminution of the pituitary size (n = 4), thinning of the pituitary stalk (n = 3) with its posterior displacement (n = 2), and evidence of iron deposition in the pituitary gland and midbrain (n = 7) in those patients with defective GH secretion (n = 9). Serum ferritin concentration was correlated significantly with the circulating IGF-I (r = -0.47, p < 0.01) and IGFBP3 (r = -0.43, p < 0.01) concentrations. These data prove a high prevalence of defective GH secretion in thalassaemic children associated with structural abnormality of their pituitary gland.

GH response to provocation and circulating IGF-I and IGF-binding protein-3 concentrations, the IGF-I generation test and clinical response to GH therapy in children with beta-thalassaemia.

The causes of growth retardation of children with thalassaemia major are multifactorial. We studied the GH response to provocation by clonidine and glucagon, measured the circulating concentrations of insulin, IGF-I, IGF-binding protein-3 (IGFBP-3) and ferritin, and evaluated IGF-I generation after a single dose of GH (0.1 mg/kg per dose) in 15 prepubertal patients with thalassaemia, 15 age-matched children with constitutional short stature (CSS) (height standard deviation score less than -2, with normal GH response to provocation) and 11 children with isolated GH deficiency (GHD). Children with thalassaemia had significantly lower peak GH response to provocation by clonidine and glucagon (6.2 +/- 2.3 and 6.8 +/- 2.1 microg/l respectively) than the CSS group (18.6 +/- 2.7 and 16.7 +/- 3.7 microg/l respectively). They had significantly decreased circulating concentrations of IGF-I and IGFBP-3 (47.5 +/- 19 ng/ml and 1.2 +/- 0.27 mg/l respectively) compared with those with CSS (153 +/- 42 ng/ml and 2.06 +/- 0.37 mg/l respectively), but the IGF-I and IGFBP-3 concentrations were not different from those with GHD (56 +/- 25 ng/ml and 1.1 +/- 0.32 mg/l respectively). These data demonstrate that the GH-IGF-I-IGFBP-3 axis in thalassaemic children is defective. Serum ferritin concentration correlated significantly with GH peak response to provocation (r = -0.36, P < 0.05) and circulating IGF-I (r = -0.47, P < 0.01) and IGFBP-3 (r = -0.42, P < 0.01) concentrations. In the IGF-I generation test, after GH injection, the thalassaemic children had significantly lower IGF-I and IGFBP-3 levels 86.7 +/- 11.2 ng/ml and 2.05 +/- 0.51 mg/l respectively) than those in the CSS group (226 +/- 45.4 ng/ml and 2.8 +/- 0.43 mg/l respectively). The IGF-I response was significantly higher in children with GHD (158 +/- 50 ng/ml) than in thalassaemic children. Six short (height standard deviation score less than -2) thalassaemic children who had defective GH response to provocation (< 10 microg/l), all the children with GHD and eight short normal children (CSS) were treated for 1 year with human GH (18 units/m2 per week divided into daily s.c. doses). After 1 year of GH therapy there was a marked acceleration of growth velocity in both thalassaemic children (from 3.8 +/- 0.6 cm/year to 7.2 +/- 0.8 cm/year) and controls. However, the linear acceleration of growth velocity on GH therapy was significantly slower in thalassaemic children (3.3 +/- 0.3 cm/year increment) compared with those with CSS (5.3 +/- 0.4 cm/year increment) and GHD (6.9 +/- 1.2 cm/year increment) (P < 0.05). Their circulating IGF-I concentration (105 +/- 36 ng/ml) was significantly lower than those for CSS (246 +/- 58 ng/ml) and GHD (189 +/- 52 ng/ml) after 1 year of GH therapy. These data prove that some children with beta-thalassaemia major have a defective GH-IGF-I-IGFBP-3 axis and suggest the presence of partial resistance to GH.

Bone mineral density in prepubertal children with beta-thalassemia: correlation with growth and hormonal data.

Patients with beta-thalassemia major (beta-thalassemia) frequently have bone disorders of multifactorial etiology. We attempted to analyze the relationship between the bone mineral density ([BMD] measured by dual-photon absorptiometry) and auxanologic parameters, degree of siderosis, function of the growth hormone (GH)/insulin-like growth factor-I (IGF-I)/IGF-binding protein-3 (IGFBP3) axis, calcium-phosphate balance, parathyroid hormone (PTH), and cytokines (interleukin-1beta [IL-1] and tumor necrosis factor-alpha [TNF-alpha]) in 30 prepubertal children with beta-thalassemia major and 15 age-matched children with constitutional short stature (CSS), who have normal glucose tolerance and thyroid function. Children with beta-thalassemia had a significantly decreased BMD and mean BMD% for age and sex (0.75+/-0.24 g/cm2 and 71%+/-10%, respectively) versus children with CSS (1.06+/-0.3 g/cm2 and 92%+/-7%, respectively). Thalassemic patients had significantly lower circulating concentrations of IGF-I and IGFBP3 (49+/-21 ng/mL and 1.2+/-0.25 mg/L, respectively) compared with control children (153+/-42 ng/mL and 2.1+/-0.37 mg/L, respectively). The GH response to provocation by clonidine and glucagon was defective (peak GH < 7 microg/L) in 12 of the 30 thalassemic children. Serum concentrations of IL-1beta and TNF-alpha did not differ among the two study groups. Hypocalcemia was detected in five of the 30 thalassemic patients: hypoparathyroidism was diagnosed in two of the five and rickets in the other three. BMD was highly correlated with the circulating concentrations of IGF-I and IGFBP3, as well as with the auxanologic parameters (age, weight, height, height standard deviation score [HSDS], and body mass index [BMI]). It is suggested that increasing the circulating IGF-I concentration through aggressive nutritional therapy and/or GH/IGF-I therapy with supplementation with vitamin D and/or calcium might improve bone growth and mineralization and prevent the development of osteoporosis and consequent fractures in these patients. Such therapy requires blinded controlled trials.

Dominantly inherited severe congenital neutropenia.

We report a family with autosomal dominant inherited neutropenia, characterized by maturation arrest of neutrophil precursors and hypergammaglobulinaemia. A mother, two children by her first marriage and two by her second were affected. They suffered recurrent lung, skin, ear and periodontal infections. Four have had appendicitis, and three mastoiditis. One died at 7 years from neutropenic enterocolitis, and a second at 10 years from small bowel infarction. Four who were treated with rhG-CSF responded to 5-14 micrograms/kg/day with normal neutrophil counts. Daily therapy has maintained neutrophil counts above 1000 x 10(9) per litre. Elective appendicectomy and long term G-CSF therapy are indicated.

Cerebrospinal fluid lactate in meningitis and meningococcaemia.

Cerebrospinal fluid (CSF) lactate values were measured in 26 children with meningitis (12 bacterial, 9 aseptic, 5 partially treated) and five children with meningococcaemia without meningitis. A reference range (0.5-3.2 mmol/l) was established from 100 control children. Amounts of lactate were significantly raised in bacterial meningitis (mean 6.5, range 4.5-10.2) compared with aseptic meningitis (mean 2.6, range 1.1-4.0) but this finding gave little practical help as the bacterial origin of the meningitis was clear from other CSF findings. High values (5.7) in a case of tuberculous meningitis (TBM) suggest that the test may be helpful when other CSF findings are inconclusive. Unless the CSF lactate is raised, the test is of minimal value in partially treated meningitis (mean 3.4, range 1.4-6.2). The previously unobserved finding of increased CSF lactate in meningococcaemia without meningitis (mean 3.9, range 3.1-5.0) supports the view that raised CSF lactate values in bacterial meningitis are not solely due to the presence of neutrophils. Literature relating to CSF lactate is reviewed.

Perspectives in the management of central nervous system tumours.

A general review and update in the management of CNS tumours using medulloblastoma as the main model is given in this article. Special emphasis has been placed on the benefits of combined modality treatment for brain tumours. The pathogenesis and management of these tumours is discussed and recommendations made for treatment in developing countries.

Management of gastroenteritis.

Childhood gastroenteritis remains a common reason for admission to British paediatric units, although the severity of the disease appears to be diminishing in recent years. We studied 215 infants and children with gastroenteritis admitted consecutively to four paediatric units in South Wales in order to determine the severity of the disease, the organisms isolated, the frequency of complications, and the adequacy of management before admission. Stool pathogens were isolated in 125 (58%) patients (viruses in 65, bacteria in 30, and protozoa in 19, with multiple infection found in 11). There was a low incidence of morbidity and complications, but prolonged diarrhoea (postenteritis syndrome) was present in 24 (11%) cases and 77 (36%) had received inappropriate treatment before admission. Contemporary gastroenteritis is thus a relatively mild disease in the acute phase, but management before admission to hospital is often inadequate, and prolonged diarrhoea may be a feature in a considerable number of cases.

Acyclovir in the treatment of neonatal varicella.

We describe two cases of neonatal varicella and the role of acyclovir in their treatment.