Contemporary rates of severe hypoglycaemia in youth with type 1 diabetes: variability by insulin regimen

AIMS

To determine incidence rates of severe hypoglycaemia and compare incidence rates by insulin regimen in a diverse sample of youth with Type 1 diabetes from two sites.

METHODS

In this observational study, 255 youth (51% female) aged 9-15 years receiving varied insulin regimens provided data prospectively for a median of 1.2 years. Reported episodes of severe hypoglycaemia, defined as episodes requiring help from another person for oral treatment or episodes resulting in seizure/coma, and current insulin regimens were collected systematically. Incidence rates were calculated and compared according to insulin regimen in bivariate and multivariate analyses.

RESULTS

At first encounter, participants had a median age of 12.2 years (range 9.0-15.0), median diabetes duration of 4.4 years (range 1.0-13.0) and mean HbA(1c) of 67 ± 12 mmol/mol (8.3 ± 1.1%). The incidence rate was 37.6/100 patient-years for all severe hypoglycaemia and 9.6/100 patient-years for seizure/coma. The incidence rate for severe hypoglycaemia was 31.8/100 patient-years on continuous subcutaneous insulin infusion (pump therapy), 34.4/100 patient-years on basal-bolus injections and 46.1/100 patient-years on NPH (NPH vs. pump therapy: P = 0.04). The incidence rate for seizure/coma was 4.5/100 patient-years on pump therapy, 11.1/100 patient-years on basal-bolus injections and 14.4/100 patients-years on NPH (NPH vs. pump therapy: P = 0.004). In the multivariate analysis, the rate of seizure/coma was significantly higher for those on NPH vs. pump therapy (rate ratio 2.9, P = 0.03).

CONCLUSIONS

Rates of severe hypoglycaemia in youth with Type 1 diabetes remain high. Pump therapy was associated with lower rates of all severe hypoglycaemia and seizure/coma in comparison with NPH.

Re-examining a measure of diabetes-related burden in parents of young people with Type 1 diabetes: the Problem Areas in Diabetes Survey - Parent Revised version (PAID-PR)

AIMS

In a pediatric patients, the burden of diabetes lies within the family. In the current era of intensive insulin therapy, perceived parental burden may affect the family's efforts at effective diabetes management. The aims of this study were to re-examine and revise a measure of perceived parental burden associated with caring for a child with diabetes in the current era.

METHODS

A geographically diverse population of young people (N = 376) with Type 1 diabetes and their parents included participants in the Juvenile Diabetes Research Foundation continuous glucose monitoring study and patients from the Joslin Diabetes Center. Participants provided data on demographics, diabetes management, diabetes-specific family conflict, and quality of life at baseline and after 6 months of follow-up.

RESULTS

Young people were 12.9 ± 2.7 years old with diabetes duration of 6.3 ± 3.5 years. Mean HbA(1C) was 8.0 ± 1.2%(64 mmol/mol), 58% received insulin pump therapy, and young people monitored blood glucose 5.2 ± 2.3 times/day. Factor analysis yielded two factors, 'Immediate Burden' and 'Theoretical Burden'. The Problem Areas in Diabetes Survey - Parent Revised version (PAID-PR) demonstrated excellent internal consistency (Cronbach's α = 0.87; factor 1 α = 0.78; factor 2 α = 0.83). Greater parental burden was associated with more frequent blood glucose monitoring, higher HbA(1C) levels, greater diabetes-specific family conflict, and lower quality of life. Test-retest analysis was acceptable (r = 0.62).

CONCLUSIONS

The PAID-PR demonstrated excellent internal consistency, good test-retest reliability, and associations with diabetes-specific family conflict and quality of life. This brief measure may have both clinical and research utility in the management of young people with Type 1 diabetes.

Comparison of longitudinal point-of-care and high-performance liquid chromatography HbA1c measurements in a multi-centre trial

AIMS

Point-of-care HbA(1c) is routine in clinical practice. Comparison of point-of-care HbA(1c) against laboratory measurements across sites and over time is warranted.

METHODS

One hundred and twenty-one young persons with Type 1 diabetes from four centres provided 450 paired samples collected over 10 months for point-of-care HbA(1c) and central laboratory-based high-performance liquid chromatography (HPLC) HbA(1c) determinations. Change in HbA(1c) over time was assessed by difference from initial to final HbA(1c) and by growth modelling with annualized slope calculation. Change in HbA(1c) was categorized as improved (decrease of ≥ 0.5% or negative slope), no change (± 0.4% of initial HbA(1c) or slope = 0) or worsened (increase of ≥ 0.5% or positive slope).

RESULTS

The 450 paired samples (median of four pairs/patient) were highly correlated (r = 0.97, P < 0.0001), as were time-specific and site-specific pairs (r = 0.94 to 0.98, P < 0.0001). Initial-to-final point-of-care HbA(1c) and HPLC HbA(1c) changes were 0.3 ± 1.1% (range -2.7 to 4.1) and 0.4 ± 1.2% (-3.9 to 4.5), respectively, with 21% of patients (n = 26) discordant for change categories. ΔHbA(1c) by point-of-care HbA(1c) vs. HPLC HbA(1c) differed across the HbA(1c) range and by ≥ 0.5% absolute difference in ΔHbA(1c) in 14 (54%) of the 26 patients discordant for HbA(1c) change categories. Mean annual HbA(1c) slope was 0.4 ± 1.5% (-5.4 to 4.8) for point-of-care HbA(1c) and 0.4 ± 1.6% (-6.9 to 5.2) for HPLC HbA(1c), with 18% (n = 22 pairs) discordant for change categories.

CONCLUSIONS

Assessment of absolute HbA(1c) change may not be different for point-of-care HbA(1c) compared with HPLC HbA(1c); however, misclassification of patients by discrete cut-off values may occur with point-of-care HbA(1c) compared with HPLC HbA(1c) determinations.

Validation of an abbreviated adherence measure for young people with Type 1 diabetes

AIMS

Adherence to diabetes-related tasks is an important construct. The Diabetes Self-Management Profile is a validated, semi-structured interview assessing adherence in paediatric patients with Type 1 diabetes. We created and validated a brief questionnaire version of the Diabetes Self-Management Profile called the Diabetes Self-Management Questionnaire.

METHODS

Young people with Type 1 diabetes, ages 9-15 years (n = 338) and their parents provided data from chart review, interview and questionnaires.

RESULTS

Diabetes Self-Management Questionnaire scores correlated significantly with Diabetes Self-Management Profile scores, HbA(1c) , blood glucose monitoring frequency and other measures associated with adherence and/or glycaemic control (P ≤ 0.01 for all). Young people and parent scores were correlated (r = 0.55, P < 0.0001). The Diabetes Self-Management Questionnaire demonstrated modest internal consistency (Cronbach's α = 0.59), adequate for a brief measure of multidimensional adherence. In addition, factor analysis confirmed one factor.

CONCLUSIONS

This brief adherence questionnaire demonstrated construct validity in young people 9-15 years old and their parents and may have utility in clinical and research settings.

Thiopentone elimination in newborn infants: exploring Michaelis-Menten kinetics

BACKGROUND

Thiopentone elimination has been described using Michaelis-Menten pharmacokinetics in adults after prolonged infusion or overdose, but there are few reports of elimination in neonates.

METHODS

Time-concentration profiles for neonates (n=37) given single-dose thiopentone were examined using both first-order (constant clearance) and mixed-order (Michaelis-Menten) elimination processes using nonlinear mixed effects models. These profiles included a 33-week post-menstrual age (PMA) neonate given an overdose. A two-compartment mamillary model was used to fit data. Parameter estimates were standardized to a 70 kg person using allometric models.

RESULTS

There were 197 observations available for analysis from neonates with a mean post-menstrual age of 35 (SD 4.5) weeks and a mean weight of 2.5 (SD 0.9) kg. They were given a mean thiopentone dose of 3 (SD 0.4) mg/kg as a rapid bolus. Clearance at 26 weeks PMA was 0.015 l/min/70 kg and increased to 0.119 l/min/70 kg by 42 weeks PMA. The maximum rate of elimination (V(max)) at 26 weeks PMA was 0.22 mg/min/70 kg and increased to 4.13 mg/min/70 kg by 42 weeks PMA. These parameter estimates are approximately 40% adult values at term gestation. The Michaelis constant (K(m)) was 28.3 [between subject variability (BSV) 46.4%, 95% confidence interval (CI) 4.49-99.2] mg/l; intercompartment clearance was 0.44 (BSV 97.5%, 95% CI 0.27-0.63) l/min/70 kg; central volume of distribution was 46.4 (BSV 29.2%, 95% CI 41.7-59.8) l/70 kg; peripheral volume of distribution was 95.7 (BSV 70.3%, 95% CI 61.3-128) l/70 kg.

CONCLUSIONS

Both first-order and mixed-order processes satisfactorily described elimination. First-order elimination adequately described the time-concentration profile in the premature neonate given an overdose. Clearance is immature in the pre-term neonate although there is rapid maturation around 40 weeks PMA, irrespective of post-natal age.

Influence of obesity on propofol pharmacokinetics: derivation of a pharmacokinetic model

BACKGROUND

The objective of this study was to develop a pharmacokinetic (PK) model to characterize the influence of obesity on propofol PK parameters.

METHODS

Nineteen obese ASA II patients undergoing bariatric surgery were studied. Patients received propofol 2 mg kg(-1) bolus dose followed by a 5-20-40-120 min, 10-8-6-5 mg kg(-1) h(-1) infusion. Arterial blood samples were withdrawn at 1, 3, 5 min after induction, every 10-20 min during propofol infusion, and every 10-30 min for 2 h after stopping the propofol infusion. Arterial samples were processed by high-performance liquid chromatography. Time-concentration data profiles from this study were pooled with data from two other propofol PK studies available at http://www.opentci.org. Population PK modelling was performed using non-linear mixed effects model.

RESULTS

The study involved 19 obese adults who contributed 163 observations. The pooled analysis involved 51 patients (weight 93 sd 24 kg, range 44-160 kg; age 46 sd 16 yr, range 25-81 yr; BMI 33 sd 9 kg m(-2), range 16-52 kg m(-2)). A three-compartment model was used to investigate propofol PK. An allometric size model using total body weight (TBW) was superior to all other models investigated (linear TBW, free fat mass, lean body weight, normal fat mass) for all clearance parameters. Variability in V2 and Q2 was reduced by a function showing a decrease in both parameters with age.

CONCLUSIONS

We have derived a population PK model using obese and non-obese data to characterize propofol PK over a wide range of body weights. An allometric model using TBW as the size descriptor of volumes and clearances was superior to other size descriptors to characterize propofol PK in obese patients.

Combined acetaminophen and ibuprofen for pain relief after oral surgery in adults: a randomized controlled trial

Background

Acetaminophen is often used with a non-steriodal anti-inflammatory drug for acute pain. Hitherto, these drugs have had to be given separately, typically at different time intervals. Maxigesic^® tablets combine acetaminophen and ibuprofen in clinically appropriate doses to simplify administration and dosage regimen. We compared this combination with each of the constituent drugs for the relief of pain after extraction of third molar teeth.

Methods

Adults (more than 16 yr) having one or more wisdom teeth removed under general or local anaesthesia were instructed to take two tablets before operation, then two tablets every 6 h for up to 48 h of: (i) a combination of acetaminophen 500 mg and ibuprofen 150 mg per tablet (Maxigesic^®); (ii) acetaminophen 500 mg per tablet alone; or (iii) ibuprofen 150 mg per tablet alone. The primary outcome measure was the area under the curve (AUC) of the 100 mm visual analogue scale pain measurements taken for up to 48 h after surgery, divided by time, at rest and on activity. Pharmacokinetic data were collected in a subset of patients.

Results

The mean (sem) time-corrected AUC on rest and activity, respectively, were: combination group 22.3 (3.2) and 28.4 (3.4); acetaminophen group 33.0 (3.1) and 40.4 (3.3); and ibuprofen group 34.8 (3.2) and 40.2 (3.4); P<0.01 for each of the four comparisons of combination vs constituent drug. There was no pharmacokinetic interaction between acetaminophen and ibuprofen administered together.

Conclusions

Maxigesic^® tablets provide superior pain relief after oral surgery to acetaminophen or ibuprofen alone.

Dynamics of range margins for metapopulations under climate change

We link spatially explicit climate change predictions to a dynamic metapopulation model. Predictions of species' responses to climate change, incorporating metapopulation dynamics and elements of dispersal, allow us to explore the range margin dynamics for two lagomorphs of conservation concern. Although the lagomorphs have very different distribution patterns, shifts at the edge of the range were more pronounced than shifts in the overall metapopulation. For Romerolagus diazi (volcano rabbit), the lower elevation range limit shifted upslope by approximately 700 m. This reduced the area occupied by the metapopulation, as the mountain peak currently lacks suitable vegetation. For Lepus timidus (European mountain hare), we modelled the British metapopulation. Increasing the dispersive estimate caused the metapopulation to shift faster on the northern range margin (leading edge). By contrast, it caused the metapopulation to respond to climate change slower, rather than faster, on the southern range margin (trailing edge). The differential responses of the leading and trailing range margins and the relative sensitivity of range limits to climate change compared with that of the metapopulation centroid have important implications for where conservation monitoring should be targeted. Our study demonstrates the importance and possibility of moving from simple bioclimatic envelope models to second-generation models that incorporate both dynamic climate change and metapopulation dynamics.

Morphine pharmacokinetics and pharmacodynamics in preterm and term neonates: secondary results from the NEOPAIN trial

BACKGROUND

Relationships between plasma morphine concentrations and neonatal responses to endotracheal tube (ETT) suctioning are unknown in preterm neonates.

METHODS

Ventilated preterm neonates (n=898) from 16 centres were randomly assigned to placebo (n=449) or morphine (n=449). After an i.v. loading dose (100 microg kg(-1)), morphine infusions [23-26 weeks postmenstrual age (PMA) 10 microg kg(-1) h(-1); 27-29 weeks 20 microg kg(-1) h(-1); and 30-32 weeks 30 microg kg(-1) h(-1)] were established for a maximum of 14 days. Open-label morphine (20-100 microg kg(-1)) was given for pain or agitation. Morphine assay and neonatal response to ETT suctioning was measured at 20-28 and 70-76 h after starting the drug infusion and at 10-14 h after discontinuation of the study drug. The concentration-effect response was investigated using non-linear mixed effects models.

RESULTS

A total of 5119 data points (1598 measured morphine concentrations and 3521 effect measures) were available from 875 neonates for analysis. Clearance was 50% that of the mature value at 54.2 weeks PMA (CLmat(50)) and increased from 2.05 litre h(-1) 70 kg(-1) at 24 weeks PMA to 6.04 litre h(-1) 70 kg(-1) at 32 weeks PMA. The volume of distribution in preterm neonates was 190 litre 70 kg(-1) (CV 51%) and did not change with age. There was no relationship between morphine concentrations (range 0-440 microg litre(-1)) and heart rate changes associated with ETT suctioning or with the Premature Infant Pain Profile.

CONCLUSIONS

A sigmoid curve describing maturation of morphine clearance is moved to the right in preterm neonates and volume of distribution is increased compared with term neonates. Morphine does not alter the neonatal response to ETT suctioning.

I.V. acetaminophen pharmacokinetics in neonates after multiple doses

BACKGROUND

Pharmacokinetics of an i.v. prodrug of acetaminophen (propacetamol) in neonates after repeat dosing are reported, with scant data for i.v. acetaminophen formulation.

METHODS

Neonates from an intensive care unit received 6-hourly prn i.v. acetaminophen dosed according to postmenstrual age (PMA): 28-32 weeks, 10 mg kg(-1); 32-36 weeks, 12.5 mg kg(-1); and > or =36 weeks, 15 mg kg(-1). A maximum of five blood samples for assay and liver function tests (LFTs) were collected. A one-compartment linear disposition model (zero-order input; first-order elimination) was used to describe time-concentration profiles using population modelling (NONMEM).

RESULTS

Fifty neonates, median (range) PMA 38.6 (32-45) weeks, mean (SD) weight 2.9 (0.7) kg, received a mean of 15 doses over a median 4 days with 189 serum acetaminophen and 231 LFT measurements. Standardized population parameter estimates for a term neonate were clearance (CL) 5.24 (CV 30.5%) litre h(-1) 70 kg(-1) and volume of distribution (V) 76 (29.6%) litre 70 kg(-1). CL increased with PMA from 4.4 litre h(-1) 70 kg(-1) at 34 weeks to 6.3 litre h(-1) 70 kg(-1) at 46 weeks. The presence of unconjugated hyperbilirubinaemia was associated with reduced CL: 150 micromol litre(-1) associated with 40% CL reduction. Acetaminophen concentrations between 10 and 23 mg litre(-1) at steady state are predicted after 15 mg kg(-1) 6-hourly for a neonate of PMA 40 weeks. Hepatic enzyme analysis of daily samples changed significantly for one patient whose alanine aminotransferase concentration tripled.

CONCLUSIONS

The parameter estimates are similar to those described for propacetamol. There was no evidence of hepatotoxicity. Unconjugated hyperbilirubinaemia impacts upon CL, dictating dose reduction.

Electrical properties of acupuncture points and meridians: a systematic review

According to conventional wisdom within the acupuncture community, acupuncture points and meridians are special conduits for electrical signals. This view gained popularity after anecdotal reports and clinical studies asserted that these anatomical structures are characterized by lower electrical impedance compared to adjacent controls. To ascertain whether evidence exists to support or refute this claim, we conducted a systematic review of studies directly evaluating the electrical characteristics of acupuncture structures and appropriate controls. We searched seven electronic databases until August 2007, hand-searched references, and consulted technical experts. We limited the review to primary data human studies published in English. A quality scoring system was created and employed for this review. A total of 16 articles representing 18 studies met inclusion criteria: 9 examining acupuncture points and 9 examining meridians. Five out of 9 point studies showed positive association between acupuncture points and lower electrical resistance and impedance, while 7 out of 9 meridian studies showed positive association between acupuncture meridians and lower electrical impedance and higher capacitance. The studies were generally poor in quality and limited by small sample size and multiple confounders. Based on this review, the evidence does not conclusively support the claim that acupuncture points or meridians are electrically distinguishable. However, the preliminary findings are suggestive and offer future directions for research based on in-depth interpretation of the data.

Paracetamol (acetaminophen) pharmacodynamics: interpreting the plasma concentration

Interpretation of analgesic and antipyretic responses documented after paracetamol administration is confused because response is not directly related to concentration in the blood, but rather to an effect compartment. The effect compartment does not have real measurable concentrations, but concentrations equate approximately to those observed in the cerebrospinal fluid. A time delay exists before drug reaches the effect compartment, and the equilibration half-time between the central and effect compartment is described by a single first-order parameter (Teq or T(1/2)keo), reported to be approximately 1 h for paracetamol. Paediatric analgesic studies are limited because they have only explored postoperative pain after tonsillectomy or day-stay surgery. Other pain types and pain confounders have not been investigated. Adult studies are also similarly limited. Studies investigating antipyresis have not explored the maximum response, limiting the precision of any EC(50) estimate. The influence of the cyclical nature of fever or initial temperature is seldom accounted for in antipyretic studies. Target effect compartment concentrations of 5 mg/l for fever and 10 mg/l for pain do not seem unreasonable on the basis of current literature. Speed of onset may be shortened by giving a larger initial dose or improving absorption characteristics. Consequent plasma concentration achieved, differences in effect compartment equilibration times, and the shape of the effect compartment concentration-response curve help to explain differences between common analgesic/antipyretic drugs.

Mechanism-based concepts of size and maturity in pharmacokinetics

Growth and development can be investigated using readily observable demographic factors such as weight and age. Size is the primary covariate and can be referenced to a 70-kg person with allometry using a coefficient of 0.75 for clearance and 1 for volume. The use of these coefficients is supported by fractal geometric concepts and observations from diverse areas in biology. Fat free mass (FFM) might be expected to do better than total body weight when there are wide variations in fat affecting body composition. Clearance pathways develop in the fetus before birth. The use of postnatal age as a descriptor of maturation is unsatisfactory because birth may occur prematurely; therefore postmenstrual age is a superior predictor of elimination function. A sigmoid E(max) model (Hill equation) describes gradual maturation of clearance in early life leading to a mature adult clearance achieved at a later age.

In vitro fertilization and acupuncture: clinical efficacy and mechanistic basis

OBJECTIVE

To provide an overview of the use of acupuncture as an adjunct therapy for in vitro fertilization (IVF), including an evidence-based evaluation of its efficacy and safety and an examination of possible mechanisms of action.

DESIGN

Literature review using PubMed, the Science Citation Index, The Cochrane Library (Database of Systematic Reviews and Central Register of Controlled Trials), the New England School of Acupuncture library databases, and a cross-referencing of published data, personal libraries, and Chinese medicine textbooks.

RESULTS

Limited but supportive evidence from clinical trials and case series suggests that acupuncture may improve the success rate of IVF and the quality of life of patients undergoing IVF and that it is a safe adjunct therapy. However, this conclusion should be interpreted with caution because most studies reviewed had design limitations, and the acupuncture interventions employed often were not consistent with traditional Chinese medical principles. The reviewed literature suggests 4 possible mechanisms by which acupuncture could improve the outcome of IVF: modulating neuroendocrinological factors; increasing blood flow to the uterus and ovaries; modulating cytokines; and reducing stress, anxiety, and depression.

CONCLUSIONS

More high-quality randomized, controlled trials incorporating placebo acupuncture controls, authentic acupuncture interventions, and a range of outcome measures representative of both clinical outcomes and putative mechanistic processes are required to better assess the efficacy of acupuncture as an adjunct for IVF.

Re-assessment of risk factors for sporadic Salmonella serotype Enteritidis infections: a case-control study in five FoodNet Sites, 2002-2003

Active surveillance for laboratory-confirmed Salmonella serotype Enteritidis (SE) infection revealed a decline in incidence in the 1990s, followed by an increase starting in 2000. We sought to determine if the fluctuation in SE incidence could be explained by changes in foodborne sources of infection. We conducted a population-based case-control study of sporadic SE infection in five of the Foodborne Diseases Active Surveillance Network (FoodNet) sites during a 12-month period in 2002-2003. A total of 218 cases and 742 controls were enrolled. Sixty-seven (31%) of the 218 case-patients and six (1%) of the 742 controls reported travel outside the United States during the 5 days before the case's illness onset (OR 53, 95% CI 23-125). Eighty-one percent of cases with SE phage type 4 travelled internationally. Among persons who did not travel internationally, eating chicken prepared outside the home and undercooked eggs inside the home were associated with SE infections. Contact with birds and reptiles was also associated with SE infections. This study supports the findings of previous case-control studies and identifies risk factors associated with specific phage types and molecular subtypes.

Recent pharmacological advances in paediatric analgesics

Growth and development are two linked processes that distinguish children from adults. The use of size as the primary covariate during pharmacokinetic (PK) analyses allows exploration of the effects of age. Allometric scaling models have assisted understanding of the developmental clearance changes in common analgesic drugs such as paracetamol, morphine, tramadol and local anaesthetics agents. Single nucleotide polymorphisms (pharmacogenomics [PG]) and their impact on hepatic drug metabolism for opioids, tramadol, non-steroidal anti-inflammatory drugs (NSAIDs) and drug receptor responses are increasingly reported. Altered chemical structure or formulations of common analgesics alter pharmacodynamic (PD) effects enhancing safety and efficacy for NSAIDs by stereoselectivity and the addition of nitric oxide, for intravenous paracetamol by formulation and structural difference from propacetamol and for local anaesthetics through stereoselectivity. This article focuses upon recent data for analgesics used in paediatric pain management including paracetamol, NSAIDs, morphine, tramadol, amide local anaesthetics and ketamine. It centres on PK and clinical studies in neonates, infants and children. PG studies are acknowledged as potentially allowing individual drug therapy tailoring through a decrease in between-patient population variability, although the impact of PG in the very young is less certain. There are few data describing age-related PD changes in children despite recognition that the number, affinity and type of receptors or the availability of natural ligands changes with age.

Fibreoptic intubation skills among anaesthetists in New Zealand

The aim of this study was to investigate methods of practice, assess skill level, and evaluate attitudes towards fibreoptic intubation in the anaesthetic community of New Zealand. A postal survey questionnaire was sent to all vocationally registered anaesthetists in New Zealand and to all New Zealand anaesthetic trainees registered with the Australian and New Zealand College of Anaesthetists. There were 611 survey questionnaires posted and 386 (63%) respondents. Almost all respondents (98% of specialists, 100% of trainees) had access to fibreoptic equipment in public and 92% of respondents performed fibreoptic intubation. The median number of fibreoptic intubations performed per year was 3 for consultants and 4 for trainees. Respondents were either self taught or colleague taught (82%). Most learnt the technique on patients (92%). There were 14% who considered themselves experienced, 30% competent, 34% adequate and 20% novice. Skills were maintained by clinical patient mix in 73%. Fibreoptic intubation was considered a skill required by all anaesthetists in 87%, and 66% considered it the gold standard for expected difficult airways. Lack of clinical cases requiring the skill and lack of practice were identified as the primary barriers to skill development. Consultants had greater opportunity to learn fibreoptic intubation skills during daily practice than trainees. Only 18% of trainees had a formal airway management program available to them at their place of work. There appears to be a need to increase available opportunities to perform fibreoptic intubation to enable maintenance and improvement of fibreoptic skills in our community. A formalized program of teaching fibreoptic intubation may offer greater opportunity for learning and skill development.

Scattering for mixtures of hard spheres: comparison of total scattering intensities with model

The angular dependence of the intensity of x-rays scattered from binary and ternary hard sphere mixtures is investigated and compared to the predictions of two scattering models. Mixture ratio and total volume fraction dependent effects are investigated for size ratios equal to 0.51 and 0.22. Comparisons of model predictions with experimental results indicate the significant impact of the role of particle size distributions in interpreting the angular dependence of the scattering at wave vectors probing density fluctuations intermediate between the sizes of the particles in the mixture.

Prophylactic valacyclovir to prevent outbreaks of primary herpes gladiatorum at a 28-day wrestling camp

Herpes gladiatorum (HG) plagues the sport of wrestling, especially in high school wrestlers and summer camps they attend. This study evaluated the usage of valacyclovir to prevent acquisition of primary HG, due to herpes simplex virus type 1 (HSV-1), in high school wrestlers at a 28-day wrestling camp. At the beginning and end of camp, IgM and IgG anti-HSV-1 antibodies were collected. Out of 332 male wrestlers, aged 13-20, who entered camp, 94 elected to participate in blood sampling. Sixty-four were on antiviral medication. Among the 94 wrestlers, 28 (29.8%) had positive IgG anti-HSV-1 titers. Of this group, 66 of 94, were HSV-1 IgG seronegative. At the end of camp, 55 of these original seronegative individuals elected to participate in blood sampling and none had detectable IgM anti-HSV-1 and -2 antibodies. Compared to previous years without antiviral usage, introducing prophylactic valacyclovir reduced clinical HG outbreaks by 87% at this 28-day wrestling camp. Due to the high prevalence of this virus in high school wrestlers, serological testing should be done at the beginning of each season. HSV-1 seropositive individuals should consider being on antiviral medication throughout the season to minimize the risk of transmitting the virus to other wrestlers.

Impact of ibuprofen administration on renal drug clearance in the first weeks of life

The administration of ibuprofen or any other nonselective cyclooxygenase (COX) inhibitor drug in early neonatal life is associated with a reduction of glomerular filtration, which reduces the elimination of drugs dependent on renal function for clearance. However, the relationship between COX inhibitor drug indication (prophylactic or therapeutic) and the magnitude of this effect remains unclear. Observations collected in two population pharmacokinetic studies, in preterm neonates, investigating amikacin and vancomycin were used to estimate: i) the impact of ibuprofen administration on the clearance of these drugs; and ii) the difference between prophylactic and therapeutic administration of ibuprofen on this clearance. Prophylactic administration of ibuprofen to preterm neonates on the first day of life to enhance closure of an asymptomatic patent ductus arteriosus (PDA) reduced amikacin clearance by 21% while coadministration of ibuprofen to induce closure of a symptomatic PDA resulted in an 18% reduction in vancomycin clearance in the first month of postnatal life. A significant and clinically relevant reduction in drug clearance is observed when ibuprofen is coadministered independent of indication, postmenstrual or postnatal age. Population modeling with covariate analyses can provide us with the tools to further disentangle the impact of nonselective COX-inhibitors on renal drug clearance.

Review of Staphylococcus aureus infections requiring admission to a paediatric intensive care unit

AIMS

To review clinical features and outcome of children with severe Staphylococcus aureus sepsis (SAS) presenting to a paediatric intensive care unit (PICU) with particular focus on ethnicity, clinical presentation, cardiac involvement, and outcome.

METHODS

Retrospective chart review of patients coded for SAS over 10 years (October 1993 to April 2004).

RESULTS

There were 58 patients identified with SAS over the 10 year study period; 55 were community acquired. This accounted for 4% of hospital admissions for SAS over this time; children with staphylococcal illness comprised 1% of all admissions to the PICU. Maori and Pacific children with SAS were overly represented in the PICU (81%) from a paediatric population where they contribute 21.6%. Musculoskeletal symptoms (79%) dominated presentation rather than isolated pneumonia (10%). An aggressive search for foci and surgical drainage of infective foci was required in 50% of children. Most children had multifocal disease (67%) and normal cardiac valves (95%); the few children (12%) presenting with methicillin resistant S aureus (MRSA) had community acquired infection. The median length of stay in the PICU was 3 (mean 5.8, SD 7.6, range 1-44) days. The median length of stay in hospital was 15 (mean 21, SD 22.7, range 2-149) days. Mortality due to SAS was 8.6% (95% CI 1.4-15.8%) compared with the overall mortality for the PICU of 6% (95% CI 5.3-6.7%). Ten children had significant morbidity after discharge.

CONCLUSIONS

Community acquired SAS affects healthy children, is multifocal, and has high morbidity and mortality, in keeping with the high severity of illness scores on admission. It is imperative to look for sites of dissemination and to drain and debride foci. Routine echocardiography had low yield in the absence of pre-existing cardiac lesions, persisting fever, or persisting bacteraemia.