A survey of staffing levels in paediatric diabetes services throughout the UK.

AIMS: To assess staffing levels of healthcare professionals involved in the care of children and young people with diabetes in the UK. METHODS: A web-based questionnaire was distributed to lead consultant paediatricians from all paediatric diabetes services in the UK between October and December 2014. Data on staffing levels and other aspects of diabetes services were collected and differences between the four nations of the UK and across the 10 English diabetes networks were explored. RESULTS: Some 175 services (93%) caring for 29 711 children and young people aged ≤ 24 years with diabetes participated in the survey. Northern Ireland and Wales had the lowest ratio of total staff to patient population. Nursing caseloads per one whole-time equivalent (WTE) nurse ranged from 71 patients in England to 110 patients in Northern Ireland with only 52% of the UK services meeting the Royal College of Nursing recommended nurse-to-patient ratio of > 1 : 70. Scotland and Northern Ireland had the highest ratio of consultants and fully trained doctors per 1000 patients (3.5 WTE). Overall, 17% of consultants had a Certificate of Completion of Training in Endocrinology and Diabetes. Some 44% of dietitians were able to adjust insulin dose. Only 43% of services provided 24-h access to advice from the diabetes team and 82% of services had access to a psychologist. Staffing levels adjusted for volume were not directly related to glycaemic performance of services in England and Wales. CONCLUSIONS: Wide variations in staffing levels existed across the four nations of the UK and important gaps were present in key areas.

Diabetic ketoacidosis in an adolescent and young adult population in the UK in 2014: a national survey comparison of management in paediatric and adult settings.

AIMS: To assess the management of diabetic ketoacidosis in young people, which differs in the UK between paediatric and adult services, and to evaluate outcomes and extent to which national guidelines are used. METHODS: A standardized questionnaire was sent to all paediatric and adult diabetes services in England, requesting details of all diabetic ketoacidosis admissions in young people aged > 14 years in paediatric services ('paediatric' patients), and in young adults up to the age of 22 years in adult services ('adult' patients). RESULTS: A total of 64 adult patients aged ≤ 22 years (mean age 19.2 years) were reported, of whom seven were aged between 10 and 16 years. A total of 71 paediatric patients were reported [mean (range) age 14.9 (11-18) years]. We found that 85% of paediatric and 69% of adult patients were treated according to national guidelines, 99% of paediatric and 89% of adult patients were treated with 0.9% saline and fixed-rate insulin infusions and 16% of adult patients received an insulin bolus. Insulin treatment was initiated later in paediatric patients than in adult patients (100 vs 39 min; P < 0.001). In 23% of adult patients and 8.8% of paediatric patients, potassium levels were < 3.5 mmol/l (P < 0.005). The lowest mean potassium levels were 3.8 mmol/l in paediatric and 3.5 mmol/l in adult patients (P < 0.005). Hypoglycaemia occurred in 42.3% of paediatric and 36% of adult patients. Time to resolution was similar in paediatric and adult patients (16.0 vs 18.2 h), as was duration of hospital stay (2.35 vs 2.53 days). CONCLUSIONS: Young people were treated according to national guidelines, but the quality of monitoring was variable in both paediatric and adult settings. The incidence of hypoglycaemia and hypokalaemia was unacceptably high.

Identifying targets to reduce the incidence of diabetic ketoacidosis at diagnosis of type 1 diabetes in the UK.

BACKGROUND: Diabetic ketoacidosis (DKA) is the leading cause of mortality in childhood diabetes, and at diagnosis might represent delayed presentation. The extent and reasons for delays are unclear, but identifying and targeting factors associated with DKA could reduce this incidence. OBJECTIVE: To compare the patient pathway before diagnosis of type 1 diabetes mellitus (T1DM) in children presenting with DKA and non-acidotic hyperglycaemia. DESIGN, SETTING AND PATIENTS: Over a 3-month period, children newly diagnosed with T1DM were identified on admission to UK hospitals. Parents and medical teams completed a questionnaire about events before diagnosis. RESULTS: Data were available for 261 children (54% male), median age 10.3y (range 0.8-16.6 y). 25% presented with DKA, but more commonly in children <2y (80% vs 23%, p<0.001). Fewer children with DKA reported polyuria (76% vs 86%) or polydipsia (86% vs 94%) (both p<0.05), but more reported fatigue (74% vs 52%) and weight loss (75% vs 54%) (both p<0.01). 24% of children had multiple healthcare professional (HCP) contacts, and these children had lower pH on admission. 46% of children with a delayed presentation to secondary care had non-urgent investigations. 64% of parents had considered a diagnosis of diabetes, and these children were less likely to present with DKA (13% vs 47%, p<0.001). CONCLUSIONS: Multiple HCP contacts increased risk of presentation in DKA, whereas, parental awareness of diabetes was protective. Improved public and health professional education targeting non-classical symptoms, awareness of diabetes in under 2 y, and point-of-care testing could reduce DKA at diagnosis of diabetes.

Care of children with diabetes as inpatients: frequency of admissions, clinical care and patient experience.

AIM: Hospital inpatient care for children with diabetes is frequently mentioned by parents as unsatisfactory. The aim of this study was to examine the reasons for inpatient admission of children with diabetes and to understand patient and carer experience in order to improve services. METHODS: Questionnaires were given to medical teams, parents and children during admissions of children with diabetes under 16 years of age in three regions of England. RESULTS: There were 401 admissions over 6 months from 3247 patients: 334 (83%) emergency admissions and 59 (15%) elective; the reason is unknown in eight (2%). One hundred and forty-three (36%) were emergency admissions with diabetic ketoacidosis/hyperglycaemia. Clinical teams reported adverse events around insulin administration in 25, hypoglycaemia (sometimes recurrent) in 120 and food provision in 14 admissions. Others included seven incidents around elective surgery. Diabetes clinical teams were not always informed about admissions and only 33% were informed within 2 h. Parents and children reported fewer problems: 62% were involved in care most of the time and 87% were able to give insulin. Most negative comments were about poor staff management of out-of-range blood glucose levels, knowledge of insulin pumps and care of children waiting in the emergency department. CONCLUSIONS: There were a large number of admissions and the majority were emergencies. Parents generally felt that they receive good care, although with some lack of knowledge amongst the ward staff. There were an unacceptable number of adverse incidents reported. We recommend that education of ward staff in diabetes is carried out regularly with reference to the standards of care.

Persistent individual tracking within overall improvement in HbA1c in a UK paediatric diabetes clinic over 15 years.

INTRODUCTION: There is some evidence of long-term tracking of HbA(1c) levels within diabetes centres, but little evidence of individual tracking. METHODS: HbA(1c) levels of children in the clinic over a period of 15 years were retrieved from the clinical chemistry laboratory information system. We measured the correlation of HbA(1c) between years (Spearman and Pearson rank correlation), as well as the relationship of HbA(1c) with age and the change over time in the clinic. RESULTS: Data were collected from 362 children and young people [158 female (44%)], aged 0-18 years (median 10.4 years), with 0-13.6 years of follow-up (median 4.7 years). Mean HbA(1c) levels fell from 9.3 ± 1.5% (78 ± 16 mmol/mol) in 2001 to 8.1 ± 1.3% (65 ± 14 mmol/mol) in 2009 in those at least 6 months after diagnosis (P<0.0001). HbA(1c) levels gradually rise with increasing age. HbA(1c) levels from year to year are significantly correlated. This is better for adjacent than subsequent years, but there is a significant correlation up to 9 years from diagnosis. Only 4 of 49 children with a 6-month HbA(1c) level of 9% (75 mmol/mol) or more had a long-term (2-5 years) median HbA(1c) <8% (64 mmol/mol). CONCLUSIONS: HbA(1c) levels track in individuals within an improvement in overall clinic levels, suggesting that, if optimal control can be achieved in the first 6 months, it can persist for up to 9 years.

Can children with Type 1 diabetes and their caregivers estimate the carbohydrate content of meals and snacks?

AIMS: Carbohydrate (CHO) counting allows children with Type 1 diabetes to adjust mealtime insulin dose to carbohydrate intake. Little is known about the ability of children to count CHO and whether a particular method for assessing CHO quantity is better than others. We investigated how accurately children and their caregivers estimate carbohydrate, and whether counting in gram increments improves accuracy compared with CHO portions or exchanges. METHODS: One hundred and two children and adolescents (age range 8.3-18.1 years) on intensive insulin therapy and 110 caregivers independently estimated the CHO content of 17 standardized meals (containing 8-90 g CHO), using whichever method of carbohydrate quantification they had been taught (gram increments, 10-g portions or 15-g exchanges). RESULTS: Seventy-three per cent (n = 2530) of all estimates were within 10-15 g of actual CHO content. There was no relationship between the mean percentage error and method of carbohydrate counting or glycated haemoglobin (HbA(1c)) (P > 0.05). Mean gram error and meal size were negatively correlated (r = -0.70, P < 0.0001). The longer children had been CHO counting the greater the mean percentage error (r = 0.173, P = 0.014). Core foods in non-standard quantities were most frequently inaccurately estimated, while individually labelled foods were most often accurately estimated. CONCLUSIONS: Children with Type 1 diabetes and their caregivers can estimate the carbohydrate content of meals with reasonable accuracy. Teaching CHO counting in gram increments did not improve accuracy compared with CHO portions or exchanges. Large meals tended to be underestimated and snacks overestimated. Repeated age-appropriate education appears necessary to maintain accuracy in carbohydrate estimations.

Children and adolescents on intensive insulin therapy maintain postprandial glycaemic control without precise carbohydrate counting.

AIMS: Carbohydrate (CHO) quantification is used to adjust pre-meal insulin in intensive insulin regimens. However, the precision in CHO quantification required to maintain postprandial glycaemic control is unknown. We determined the effect of a +/-10-g variation in CHO amount, with an individually calculated insulin dose for 60 g CHO, on postprandial glycaemic control. METHODS: Thirty-one children and adolescents (age range 9.5-16.8 years), 17 using continuous subcutaneous insulin infusion (CSII) and 14 using multiple daily injections (MDI), participated. Each subject consumed test lunches of equal macronutrient content, differing only in carbohydrate quantity (50, 60, 70 g CHO), in random order on three consecutive days. For each participant, the insulin dose was the same for each meal, based on their usual insulin : CHO ratio for 60 g CHO. Activity was standardized. Continuous glucose monitoring was used. RESULTS: The CSII and MDI subjects demonstrated no difference in postprandial blood glucose levels (BGLs) for comparable carbohydrate loads (P > 0.05). The 10-g variations in CHO quantity resulted in no differences in BGLs or area under the glucose curves for 2.5 h (P > 0.05). Hypoglycaemic episodes were not significantly different (P = 0.32). The 70-g meal produced higher glucose excursions after 2.5 h, with a maximum difference of 1.9 mmol/l at 3 h (P = 0.01), but the BGLs remained within international postprandial targets. CONCLUSIONS: In patients using intensive insulin therapy, an individually calculated insulin dose for 60 g of carbohydrate maintains postprandial BGLs for meals containing between 50 and 70 g of carbohydrate. A single mealtime insulin dose will cover a range in carbohydrate amounts without deterioration in postprandial control.

Longitudinal screening of serum lipids in children and adolescents with Type 1 diabetes in a UK clinic population.

AIMS: To determine the prevalence of abnormal lipid levels in a large group of children and adolescents with Type 1 diabetes and to examine the changes longitudinally. In addition, to study the relationships of any lipid abnormalities to glycaemic control, age and duration of diabetes. METHODS: Non-fasting blood samples were taken annually from all the patients in the Oxford Children's diabetes clinic and total cholesterol (TC), high-density lipoprotein (HDL) cholesterol, triglycerides (TG) and glycated haemoglobin (HbA(1c)) measured over a period of 8 years. Low-density lipoprotein (LDL) cholesterol and non-HDL were calculated from these values and compared. Tests performed less than 4 months after diagnosis were excluded. RESULTS: A total of 229 children had complete data from more than 1 year and 798 sets of data were examined. TC was lower in males and increased with duration of diabetes and with increasing HbA(1c). HDL cholesterol fell with increasing age, but independently increased with duration, and was not related to HbA(1c). LDL cholesterol and non-HDL cholesterol were highly correlated (r = 0.9). Both were lower in males and increased with duration of diabetes. Non-HDL cholesterol increased with HbA(1c). A total of 23.7% had HDL cholesterol < 1.1 mmol/l and 22.5% had TC > 5.2 mmol/l. Thirty-eight per cent had LDL cholesterol > 2.6 mmol/l and 10.8% > 3.4 mmol/l, the thresholds for lifestyle and drug intervention respectively. CONCLUSIONS: Abnormalities in plasma lipid levels are common in this age group and the prevalence increases with poor glycaemic control and with duration of diabetes. Around 10% of adolescents would fit criteria for lipid-lowering medication in adults, but further study is needed to examine the risks and benefits in this age group.

Can we identify adolescents at high risk for nephropathy before the development of microalbuminuria?

AIMS: To determine whether higher than average albumin excretion during early puberty identifies subjects who will subsequently develop microalbuminuria (MA) and clinical proteinuria. METHODS: Longitudinal data from the Oxford Regional Prospective Study of Childhood Diabetes (ORPS; n = 554, median duration of follow-up 10 years; range 3.0-16.7) with assessment of albumin/creatinine ratios in three early morning urine samples collected annually. An albumin excretion phenotype was derived from longitudinal data, for each individual, defining deviation from the mean of regression models, including covariates gender, age, duration of diabetes and age at assessment. Tracking of the phenotypes was confirmed in a second independent cohort from Perth, Australia. RESULTS: The albumin excretion phenotype showed reasonable correlation between age 11-15 years and age 16-18 years in both cohorts, indicative of good 'tracking'. In the ORPS cohort, tertiles of the albumin excretion phenotype at aged 11-15 years were predictive of subsequent risk for the development of MA. All of the subjects developing clinical proteinuria had an albumin excretion phenotype in the upper tertile or an HbA(1c) > 9% at aged 11-15 years. CONCLUSIONS: Identification of adolescents at risk of diabetic nephropathy using an albumin excretion phenotype is feasible. When combined with elevated HbA(1c), it may identify subjects for trial of early intervention with angiotensin-converting enzyme inhibitors/angiotensin-II receptor antagonists and statins to improve long-term prognosis in these subjects where sustained improvement in glycaemic control may be difficult to achieve.

The UK case-control study of cerebral oedema complicating diabetic ketoacidosis in children.

AIMS/HYPOTHESIS: Cerebral oedema complicating diabetic ketoacidosis (DKA) remains the major cause of morbidity and mortality in children with type 1 diabetes, but its aetiology remains unknown. Our objective was to determine the impact of baseline biochemical factors and of treatment-related variables on risk of the development of cerebral oedema in children with DKA. MATERIALS AND METHODS: This was a national UK case-control study. Through the British Paediatric Surveillance Unit we identified 43 cases of cerebral oedema. Through a parallel reporting system, we also identified 2,940 episodes of DKA and selected 169 control subjects on the basis of comparable age, sex, numbers of new or known cases of diabetes and date of admission. Baseline biochemical data and treatment-related variables were extracted from the clinical notes of cases and control subjects. RESULTS: Allowing for differences in age, sex and new or known diabetes, cases were more acidotic at diagnosis of DKA (odds ratio [OR] for events in the least acidotic compared with the most acidotic tertile=0.02 [95% CI: 0.002-0.15], p<0.001). In addition, cases had higher potassium and urea levels at baseline. Calculated osmolality and baseline glucose were not significantly different. After allowing for severity of acidosis, insulin administration in the first hour (OR 12.7 [1.41-114.5], p=0.02) and volume of fluid administered over the first 4 h (OR 6.55 [1.38-30.97], p=0.01) were associated with risk. Low baseline plasma sodium and an elevated p(a)CO(2) also contributed to risk in the final regression model. Bicarbonate administration was not associated with increased risk of an event when corrected for acidosis. CONCLUSIONS/INTERPRETATION: In this case-control study of DKA, baseline acidosis and abnormalities of sodium, potassium and urea concentrations were important predictors of risk of cerebral oedema. Additional risk factors identified were early administration of insulin and high volumes of fluid. These observations should be taken into account when designing treatment protocols.

Diabetes services in the UK: fourth national survey; are we meeting NSF standards and NICE guidelines?

BACKGROUND: Previous surveys of children's diabetes service provision in the UK have shown gradual improvements but continuing deficiencies. AIM: To determine whether further improvements in services have occurred. METHODS: A questionnaire was mailed to all paediatricians in the UK identified as providing care for children and adolescents with diabetes. Responses were compared with results of three previous surveys, and with recommendations in the Diabetes NSF and the NICE type 1 diabetes guidelines. RESULTS: Replies were received from 187 consultant paediatricians in 169 centres looking after children; 89% expressed a special interest in diabetes, 98% saw children in a designated diabetic clinic, and 95% clinics now have more than 40 patients. In 98% of the clinics there was a specialist nurse (82% now children's trained), but 61% clinics had a nurse:patient ratio <1:100; 39% of clinics did not have a paediatric dietician and in 78% there was no access to psychology/psychiatry services in clinics. Glycated haemoglobin was measured routinely at clinics in 86%, annual screening for retinopathy performed in 80%, and microalbuminuria in 83%. All centres now have local protocols for ketoacidosis, but not for children undergoing surgery (90%) or severe hypoglycaemia (74%). Mean clinic HbA1c levels were significantly lower in the clinics run by specialists (8.9%) than generalists (9.4%). There have been incremental improvements over the last 14 years since the surveys began, but only two clinics met all the 10 previously published recommendations on standards of care. CONCLUSIONS: The survey shows continuing improvements in organisational structure of services for children with diabetes but serious deficiencies remain. Publication and dissemination of the results of the previous surveys may have been associated with these improvements and similar recurrent service review may be applicable to services for other chronic childhood conditions.

Prolonged cardiac repolarisation during spontaneous nocturnal hypoglycaemia in children and adolescents with type 1 diabetes.

AIMS/HYPOTHESIS: It has been postulated that hypoglycaemia-related cardiac dysrhythmia and, in particular, prolonged cardiac repolarisation, may contribute to increased mortality rates in children and adolescents with type 1 diabetes. METHODS: We examined the prevalence of prolonged QT interval on ECG during spontaneous hypoglycaemia in 44 type 1 diabetic subjects (aged 7-18 years), and explored the relationships between serial overnight measurements of QT interval corrected for heart rate (QTc) and serum glucose, potassium and epinephrine levels. Each subject underwent two overnight profiles; blood was sampled every 15 min for glucose measurements and hourly for potassium and epinephrine. Serial ECGs recorded half-hourly between 23.00 and 07.00 hours were available on 74 nights: 29 with spontaneous hypoglycaemia (defined as blood glucose <3.5 mmol/l) and 45 without hypoglycaemia. RESULTS: Mean overnight QTc was longer in females than in males (412 vs 400 ms, p=0.02), but was not related to age, diabetes duration or HbA(1)c. Prolonged QTc (>440 ms) occurred on 20 out of 74 (27%) nights, with no significant differences between male and female subjects, and was more prevalent on nights with hypoglycaemia (13/29, 44%) than on nights without (7/45, 15%, p=0.0008). Potassium levels were lower on nights when hypoglycaemia occurred (minimum potassium 3.4 vs 3.7 mmol/l, p=0.0003) and were inversely correlated with maximum QTc (r=-0.40, p=0.03). In contrast, epinephrine levels were not higher on nights with hypoglycaemia and were not related to QTc. CONCLUSIONS/INTERPRETATION: In young type 1 diabetic subjects, prolonged QTc occurred frequently with spontaneous overnight hypoglycaemia and may be related to insulin-induced hypokalaemia.

Insulin lispro: a potential role in preventing nocturnal hypoglycaemia in young children with diabetes mellitus.

AIMS: The long duration of action of soluble insulin given in the evening could contribute to the high prevalence of nocturnal hypoglycaemia seen in young children with Type 1 diabetes mellitus (T1DM). We examined whether replacing soluble insulin with insulin lispro reduced this risk in children on a three times daily insulin regimen. METHODS: Open crossover study comparing insulin lispro vs. soluble insulin in 23 (16 boys) prepubertal children (age 7-11 years) with T1DM on three injections/day; long-acting isophane insulin remained identical. At the end of each 4-month treatment arm, an overnight 15-min venous sampled blood glucose profile was performed. RESULTS: Despite similar blood glucose levels pre-evening meal (lispro vs. soluble: mean +/- se 6.5 +/- 1.0 vs. 7.1 +/- 1.1 mmol/l, P = 0.5), post-meal (18.00-22.00 h) blood glucose levels were lower on insulin lispro (area under curve 138 +/- 12 vs. 170 +/- 13 mmol min-1 l-1, P = 0.03). In contrast, in the early night (22.00-04.00 h) the prevalence of low blood glucose levels (< 3.5 mmol/l) was lower on lispro (8% of blood glucose levels) than on soluble insulin (13%, P = 0.01). In the early morning (04.00-07.00 h) mean blood glucose and prevalence of low levels were no different between the two treatment groups, and fasting (07.00 h) blood glucose levels were similar (6.1 +/- 0.8 vs. 6.3 +/- 0.9 mmol/l, P = 0.8). At the end of each treatment arm there were no differences in HbA1c (lispro vs. soluble 8.6% vs. 8.4%, P = 0.3), or in insulin doses (mean, range 0.97, 0.68-1.26 vs. 0.96, 0.53-1.22 U/kg per day, P = 0.2). CONCLUSIONS: The shorter duration of action of insulin lispro given before the evening meal may reduce the prevalence of early nocturnal hypoglycaemia without compromising HbA1c in young children with T1DM.

Current methods of transfer of young people with Type 1 diabetes to adult services.

AIMS: To determine the efficacy and patient perception of various transfer procedures from paediatric to adult diabetes services. METHODS: Comparison between four districts in the Oxford Region employing different transfer methods, by retrospective study of case records and interviews of patients recently transferred from paediatric diabetes clinics. The main outcome measures were age at transfer, clinic attendance rates, HbA1c measurements and questionnaire responses. RESULTS: Two hundred and twenty-nine subjects (57% males) > 18 years old in 1998 and diagnosed with Type 1 diabetes < 16 years of age between 1985 and 1995, identified from the regional diabetes register. The notes audit was completed for 222 (97%) and 164 (72%) were interviewed by a single research nurse. Mean age at transfer was 17.9 years (range 13.3-22.4 years). Few young people were lost to follow-up at the point of transfer. There was a high rate of clinic attendance (at least 6 monthly) 2 years pretransfer (94%), but this declined to 57% 2 years post-transfer (P < 0.0005). There was large interdistrict variation in clinic attendance 2 years post-transfer (29% to 71%); higher rates were seen in districts where young people had the opportunity to meet the adult diabetes consultant prior to transfer. The importance of this opportunity was confirmed by questionnaire responses on interview. CONCLUSIONS: Adolescence is a vulnerable period for patients with diabetes. This regional survey demonstrated a marked decline in clinic attendance around the time of transition from paediatric to adult services. The reasons are complex, but mode of transfer may be an important factor.

Cerebral venous thrombosis during diabetic ketoacidosis.

Neurological deterioration during an episode of diabetic ketoacidosis is usually assumed to be caused by cerebral oedema. We present a case of cerebral venous sinus thrombosis presenting in a similar manner, also associated with severe iron deficiency anaemia. Computed tomography scanning provided the correct diagnosis and allowed institution of anticoagulation with improvement in neurological outcome. Neuroimaging should always be performed in suspected cerebral oedema associated with diabetic ketoacidosis in order to exclude other pathologies.

The risk and outcome of cerebral oedema developing during diabetic ketoacidosis.

BACKGROUND: Cerebral oedema is a major cause of morbidity and mortality in children with insulin dependent diabetes. AIMS: To determine the risk and outcome of cerebral oedema complicating diabetic ketoacidosis (DKA). METHODS: All cases of cerebral oedema in England, Scotland, and Wales were reported through the British Paediatric Surveillance Unit between October 1995 and September 1998. All episodes of DKA were reported by 225 paediatricians identified as involved in the care of children with diabetes through a separate reporting system between March 1996 and February 1998. Further information about presentation, management, and outcome was requested about the cases of cerebral oedema. The risk of cerebral oedema was investigated in relation to age, sex, seasonality, and whether diabetes was newly or previously diagnosed. RESULTS: A total of 34 cases of cerebral oedema and 2940 episodes of DKA were identified. The calculated risk of developing cerebral oedema was 6.8 per 1000 episodes of DKA. This was higher in new (11.9 per 1000 episodes) as opposed to established (3.8 per 1000) diabetes. There was no sex or age difference. Cerebral oedema was associated with a significant mortality (24%) and morbidity (35% of survivors). CONCLUSIONS: This first large population based study of cerebral oedema complicating DKA has produced risk estimates which are more reliable and less susceptible to bias than those from previous studies. Our study indicates that cerebral oedema remains an important complication of DKA during childhood and is associated with significant morbidity and mortality. Little is known of the aetiology of cerebral oedema in this condition and we are currently undertaking a case control study to address this issue.

Cerebral oedema during treatment of diabetic ketoacidosis: are we any nearer finding a cause?

Cerebral oedema remains the leading cause of death and morbidity in children with Type 1 diabetes mellitus. Around seven per thousand episodes of diabetic ketoacidosis (DKA) are complicated by cerebral oedema, and one-quarter of those children will die from it. The cause or causes of cerebral oedema are still very poorly understood, but lawyers are already keen to implicate various aspects of the management of DKA. There have been many theories as to the pathophysiology of cerebral oedema, and possible contributing factors may be excessive rate of rehydration, falling plasma osmolality (particularly that due to a reduction in plasma sodium concentration), hypoxia and insulin dosage. There is some supportive evidence for all of these factors in some cases, but there have been no sizeable case-control studies, in part because of the rarity of the condition. Furthermore, cerebral oedema can still occur even when the management of DKA follows current 'best practice' guidelines. As the mechanisms of cell volume regulation within the brain are increasingly understood, different questions may provide greater insights. For example, what is it about children that makes them so much more susceptible to cerebral oedema than adults? And why does one child treated in a certain way develop cerebral oedema whereas another does not? The anxiety over causing cerebral oedema has driven most of the changes in the management of DKA over recent decades, yet there is no evidence that the incidence has reduced. Until the causes are understood, we cannot be dogmatic about treatment recommendations.