Early neonatal presentations to the pediatric emergency department.

UNLABELLED: As a result of shorter postpartum hospital stays, many medical concerns, which traditionally have been managed in newborn nurseries, are presenting to the pediatric emergency department (PED). We undertook a study to determine the profile of early neonatal visits to the PED. In addition, we examined the influence of maternal factors and length of postpartum hospital stay on PED visits. METHODS: We conducted a retrospective chart review of all neonates < or = 8 days of age who presented to the PED between June 1990 and May 1995. Data gathered from neonatal and corresponding maternal charts included neonatal and maternal demographics, prenatal instruction, length of postpartum stay, source of referral, age at presentation, presenting complaint, diagnosis, disposition, and course in hospital, if admitted. RESULTS: A total of 559 neonatal visits were identified. Neonatal use of the PED increased 245% compared to an overall increase in PED use of 8.7% during the study period. Jaundice, difficulty breathing, feeding problems, and irritability were the most common presenting complaints while the most frequent diagnoses were normal physiology, jaundice, feeding problems, and query sepsis. Our overall admission rate was 33%. Self-referred patients were at a significantly lower risk of serious illness (16% admitted vs 49 % of consult patients). The self-referral rate increased with maternal age less than 21, single marital status, no prenatal classes, and primiparity. The length of postpartum hospital stay was identified in 389 neonates (55 early discharge (ED) and 334 non-early discharge (NED). The ED group had a significant increase in annual PED utilization compared to the NED group changing from 2% of the total population in study year 1 to over 31% in the final year. The ED and NED groups did not differ significantly with respect to the majority of chief complaints, frequency of PED diagnoses, admission rates, or maternal characteristics. CONCLUSIONS: Use of the PED by neonates < or = 8 days of age increased significantly over the study period. The majority of neonates presented by self-referral and were discharged with advice only. Mothers who were young, single, primiparous, or who had not attended prenatal classes presented with neonates who were less seriously ill. Although ED neonates represent an enlarging subset of PED visitors, they do not appear to differ significantly from NED neonates with respect to PED complaints, diagnoses, and disposition.

Reference curves to diagnose cobalt deficiency in sheep using liver and serum vitamin B12 levels.

Reference curves demonstrating the relationship between serum or liver vitamin B12 and weight gain were derived from the examination of 16 published and 48 unpublished N.Z. trials. From these curves probability of obtaining an economic reponse (>10g/day body weight increase) for any serum or liver vitamin B12 can be determined. No significant (P<0.05) weight gain responses occurred to vitamin B12 or cobalt treatment in trials with mean serum vitamin B12 levels above 500 pmol/l or liver vitamin B12 levels greater than 500 nmol/kg. The reference curves were therefore derived from trials with vitamin B12 levels below these levels; 36 trials with serum vitamin B12 and 19 trials with liver vitamin B12 data. The mean vitamin B12 level at the mid point of the weight gain response period was selected from each trial. Examination of serum vitamin B12 reference curves for spring, summer, autumn and winter indicated that curves derived from data closest to the middle of January (summer) adequately reflected response to treatment at any time during the first year of life. Reference curves for liver vitamin B12 also used data closest to middle of January. This was partly because insufficient liver data was available to compare seasonal variations. The fitted response curve approached 0 gram/day at 500 pmol/l for serum vitamin B12 and 375 nmol/kg for liver vitamin B12. The minimum vitamin B12 level at which an economic response to treatment (>10 g/day) is not likely was 336 pmol/l for serum and 282 nmol/kg for liver.

A goat mortality study in the southern North Island.

A study was undertaken to indicate the importance of different causes of death in goats and to investigate the management factors which influence these problems. Over a 15 month period, 324 dead goats were received from 67 farms in the Horowhenua, Wairarapa, Wanganui and Wellington regions. Although a wide range of diseases was encountered in the study, the major causes of mortality could be divided into 4 groups: problems directly related to management, microbial diseases, nematode parasitism, and trace element related deficiencies and toxicities. The highest proportion of deaths related directly to management problems and included deaths from hypothermia, mismothering, premature birth, ruminal acidosis, pregnancy toxaemia, trauma, and plant and chemical toxicities. In larger flocks, microbial diseases including Pasteurella pneumonia and yersiniosis were major problems. Deaths from nematode parasitism were predominantly observed in goats 12 months of age and older. White muscle disease (selenium/vitamin E deficiency) was the major trace element deficiency causing death in goats. The influence of factors including age of goat, flock size and management practices on the major causes of death are discussed.

The efficacy of intraruminal pellets composed of elemental selenium and iron in sheep.

Commercial selenium pellets, manufactured after CSIRO workers drew attention to the significance of grain size on the rate of release of selenium, were tested in 27 sheep grazing a low-selenium New Zealand pasture. The pellets were shown by microscopy to contain mainly 10-20 pm particles of selenium, often agglomerated into larger lumps. There was a considerable variation in the length of time pellets maintained blood selenium levels above the deficiency level of 250 nmol/e (20 microg/l). Whereas four animals given pellets had blood levels below 250 nmol/l after only 343 days, two animals had levels of 375 and 400 nmol/l after 651 days when the level in control sheep was 125 +/- 32 nmol/l. The pellets were recovered from all but one animal and had varying degrees of surface coating which was assumed to be mainly calcium phosphate. Two pellets recovered from sheep at 386 and 484 days, when blood selenium levels were 175 and 1813 nmol/l respectively, were sectioned and examined by light and electron microscopy. Both pellets still contained unreacted selenium but differed in the degree of surface coating. The pellet recovered at 386 days had a solid and continuous coating whereas the coating on the pellet recovered at 484 days was not continuous and consisted of an open lattice of interlocking needles. It appears that it is the extent of this coating which limits the effective life of the pellet in sheep.

The effect of copper on the response of lambs to selenium supplementation when grazing a selenium deficient pasture.

Two trials were undertaken with lambs grazing selenium deficient pasture to determine if copper would enhance liveweight and fleece-weight responses to selenium supplementation. In the first trial, lambs given selenium or selenium plus copper gained significantly more weight and had higher fleece-weights after 260 days than did control lambs or lambs given copper alone. Copper given alone or together with selenium had no significant effect on liveweight or fleece-weight when compared with control lambs and lambs that were given selenium alone respectively. This finding was confirmed in a second trial when growth and fleece-weights of selenium and selenium plus copper treated lambs were compared and no significant differences found. In both trials copper significantly raised liver copper levels. In selenium supplemented but not in selenium deficient sheep, copper significantly increased blood selenium levels.

Selenium levels in the blood, liver, kidney and muscle of sheep after the administration of iron/selenium pellets or soluble-glass boluses.

Slow-release devices composed of elemental selenium and iron or a soluble-glass containing selenium, cobalt and copper were effective in significantly raising blood and tissue selenium levels of sheep at pasture. Three out of six animals given a soluble-glass bolus lost them over the four months of the trial. In contrast, all six animals retained their iron-selenium pellets. Selenium levels in the kidney cortex four months after administration of the devices, when peak levels were most likely to occur, were approximately 12.7 micromol/kg (1mg/kg). This value is 50% of the maximum permitted level in edible tissue in New Zealand. There was no obvious pattern of distribution of selenium throughout the liver. Variations in concentration from one site to another were, in some cases, almost two-fold. Therefore the analysis of liver biopsy samples gives only an approximate assessment of the mean hepatic concentration.

The retention and efficacy of soluble-glass boluses for providing selenium, cobalt and copper to sheep.

The efficacy and retention of prototype and commercial (Cosecure) soluble-glass boluses containing selenium, cobalt and copper and having a similar size, density and composition were evaluated in separate 12-month trials with sheep grazing low selenium pastures but with adequate cobalt and copper levels. In both trials, sheep confirmed by X-ray as containing a bolus grew at a significantly greater rate than control sheep. This was attributed to the correction of a selenium deficiency. Although liver copper, and liver and serum vitamin B12 levels were significantly greater in treated sheep than controls on some occasions, the differences were not as great or consistent as with blood selenium levels. The rate of bolus loss was high and in both trials, approximately 40% of the sheep had lost the bolus after 6 months. No prototype boluses were present after 12 months. Intact Cosecure boluses were recovered from 3 sheep out of 30 after 12 months whilst one animal contained a part bolus. The recovered boluses were approximately 45% lighter than when originally administered. Bolus loss did not appear to be due to complete dissolution. In sheep which had lost the bolus, blood selenium levels fell with a half-life of 43 +/- 10 days.

Changes in blood levels of zinc, copper, selenium, glutathione peroxidase, vitamin B12 and total and free thyroxine in sheep removed from pasture and held without food for 50 hours.

Blood was collected from a group of ten sheep immediately after removal from pasture and thereafter at regular intervals for 50 hours whilst maintaining them without food but with adequate water. The samples were analysed for parameters normally examined as an aid to the diagnosis of zinc, copper, selenium, cobalt and iodine status. Serum vitamin B12 levels increased with time. Mean plasma zinc concentrations and mean serum concentrations of both T4 and fT4 followed significant parabolic trends. Maximum mean zinc levels (50 +/- 10% higher than initial values) were recorded after 30 hours. T4 and fT4 levels peaked at approximately 26 hours. Zinc levels at two hours were 20 +/- 5% lower than the initial values. Whole blood copper, selenium and glutathione peroxidase levels did not change significantly with time the largest differences were 11 +/- 6%, 5 +/- 4% and 10 +/- 8% respectively.

Failure of copper or vitamin D supplements to affect the dental condition of young sheep on two Wairarapa farms.

Regular injections of copper or vitamin D had no overall effect on growth rate, fleece weight, or the amount of wear of the central incisor teeth of sheep on two Wairarapa farms over 26 months. The greatest amount of tooth wear occurred during the period when soil ingestion (measured by acid-insoluble residue, titanium or aluminium in the faeces) was also greatest. Various indicators of copper, calcium or nutritional status were measured in the blood of control sheep and those receiving vitamin D or copper. At no sampling time was there a significant difference for any of these between groups on either farm. Pasture samples were analysed regularly for calcium, cobalt, copper, magnesium, manganese, molybdenum, phosphorus, sulphur, zinc and percentage ash. At most times values were, on the basis of existing criteria, considered normal. Although the pasture calcium/phosphorus ratio fell below one on several occasions this did not result in a change in plasma calcium or phosphorus levels. On the basis of criteria established for pen-fed sheep, dietary available copper levels on both farms were considered low for much of the time. However, liver and blood copper values were adequate at alI times.

A proposed new approach and protocol to defining mineral deficiencies using reference curves. Cobalt deficiency in young sheep is used as a model.

The most conclusive way of determining whether animals are deficient in a trace element is to measure production responses to supplementation in a field trial. However the opportunity, expertise and resources necessary to run such trials are not always readily available and there is often a considerable delay in reaching a diagnosis. Provided the degree of a production response can be closely related to a tissue level of the element or its metabolite then analysis of tissue samples can replace the need for field trials. The paper uses data from a series of cobalt liveweight response trials with lambs to outline a proposed methodology for constructing response curves which, for any specified level of Vitamin B12 in serum, can be used to determine (a) the expected liveweight response to supplementation, and (b) the probability of getting a response at least as great as some given level eg. that considered sufficient to just cover the costs of rectifying the deficiency. A protocol for future production response trials is described. It is planned that all appropriate production response trial data will be used to derive ;response; and ;probability of response; curves for use in diagnosing cobalt, selenium and copper deficiencies in sheep and cattle. It is suggested that the methodology could be applied in many biological systems involving deficiencies.

A simple restrainer for sheep for abdominal radiography.

The construction of a simple, portable restrainer for holding sheep in either the horizontal or vertical position for abdominal radiography is described. Examples of its use in locating slow-release pellets-and needles are given.

A comparison of vitamin B12 levels in the liver and serum of sheep receiving treatments used to correct cobalt deficiency.

The efficacies of four methods, used for the prophylaxis of cobalt deficiency in sheep as measured by the elevation of liver and serum vitamin B12 levels, were compared in marginally deficient sheep over 14 weeks. The methods used were weekly drenches of either cobalt sulphate or cobalt chelate (EDTA) three-weekly injections of hydroxocobalamin, and ruminal cobalt pellets. On the basis of elevated liver and serum vitamin B12 levels, chelated cobalt was shown to be available to rumen microflora for the synthesis of vitamin B12. However, at no stage were liver and serum vitamin B12 levels of sheep receiving the chelate significantly different from those receiving the same amount of cobalt as the sulphate. After five, three-weekly injections of hydroxocabalamin liver vitamin B12 levels were significantly higher (p<0.01) than for the other treatments, with the exception of cobalt sulphate. Cobalt pellets led to an initial rapid and significant rise in serum vitamin B12 when compared with the other treatments. However, at four weeks there was no significant difference between treatment groups for serum vitamin B12. Fourteen weeks after the administration of cobalt pellets, serum and liver.vitamin B12 levels in this group were not significantly different from those of untreated sheep. At this time, three out of 12 sheep had lost their pellets.

Measurement of vitamin B12 in the livers and sera of sheep and cattle and an investigation of factors influencing serum vitamin B12 levels in sheep.

Modifications of a radioassay method for the analysis of vitamin B12 using chicken serum as the binder are described. This obviates the need to use individual serum blanks to correct for non-specific binding in vitamin B12 assays of the sera and livers of sheep and cattle. Samples with high vitamin B12 levels can be diluted prior to assay without loss of linearity. Recoveries of added cyanocobalamin or hydroxocobalamin were better than 95% and results correlated significantly with those obtained using a microbiological assay (Poteriochromonas malhamensis). Sera and liver samples stored for four weeks at temperatures ranging from -20 degrees to 22 degrees showed no change in vitamin B12 levels. Withholding food from sheep for 44 hours led to a marked increase in serum vitamin B12. This effect was also evident in sheep eating a limited amount of cut grass. In sheep at pasture there was no evidence of a diurnal variation in serum vitamin B12 levels. Serum vitamin B12 levels in sheep at pasture were shown to be an unreliable indicator of liver vitamin B12.

Copper metabolism in growing sheep given kale (Brassica oleracea) and ryegrass (Lolium perenne)-clover (Trifolium repens) fresh forage diets.

Kale (Brassica oleracea) and ryegrass (Lolium perenne)-clover (Trifolium repens) pasture grown under similar soil conditions were grazed in the vegetative state by growing lambs of 23.6 kg initial live weight for 24 weeks. Forty-eight lambs grazed each forage. The kale and pasture contained respectively 4 and 14 mg copper/kg dry matter (DM), 7.2 and 3.1 g total sulphur/kg DM and 0.4 and 1.1 mg molybdenum/kg DM. Subcutaneous injections of Cu (12 mg) were given to half the animals grazing each forage during weeks 1, 6, 12 and 18. All ninety-six animals were slaughtered at the end of the experiment and an additional group of twelve animals was slaughtered when the experiment commenced. Liver Cu was determined on all slaughtered animals and heart muscle cytochrome oxidase (EC 1.9.3.1) activity on those slaughtered at week 24. Blood samples removed at 6-week intervals were assayed for activity of superoxide dismutase (EC 1.15.1.1; SOD) and serum Cu concentration determined. Wool growth, live-weight gain and cytochrome oxidase activity of biopsied hind-limb muscle were also measured at 6-week intervals. Control animals grazing pasture showed an accumulation of total liver Cu during the experiment. Animals grazing this diet and given Cu injections showed an additional accumulation of liver Cu equivalent to the supplementary Cu administered, but Cu supplementation did not affect the activity of any of the Cu-containing enzymes measured and did not affect live-weight gain or wool growth. Control animals grazing kale showed a depletion of total liver Cu and reductions in serum Cu concentrations during weeks 18 and 24.(ABSTRACT TRUNCATED AT 250 WORDS)

The distribution of copper, vitamin B12 and zinc in the livers of sheep.

Six livers from one-year-old sheep were each sampled at 27 different sites and the concentrations of copper, vitamin B12 and zinc determined for each sample. The distribution of these components was uniform throughout the liver, indicating that analysis of a single liver biopsy sample would give an accurate assessment of their hepatic concentration.

Failure of orally administered zinc to prevent experimentally induced footrot in sheep.

Two groups of adult Merino sheep, initially grazed on pasture, were dosed daily with zinc sulphate (1 mg Zn/kg LW) or zinc oxide (15 mg Zn/kg LW) for six and seven weeks, respectively. On the 18th day, both groups were transferred to indoor pens together with unmedicated control sheep, and five days later the feet of all animals were infected artificially with a virulent strain of Bacteroides nodosus. By the fourth week after challenge, 85% or more of the feet challenged had developed advanced footrot, and no significant differences in the incidence and severity of lesions between dosed and un-dosed groups were recorded. Plasma zinc concentrations, monitored throughout the experiment, remained at similar levels in sheep receiving the lower dose rate and in the controls. At the higher dose rate, plasma zinc levels increased till Day 23, but thereafter declined to values comparable to those of undosed animals. At post mortem, no evidence of zinc toxicosis was found, and only the kidneys of sheep receiving the higher dosage showed a significant accumulation of zinc compared with the controls.