Service and support needs following pediatric brain injury: perspectives of children with mild traumatic brain injury and their parents.

OBJECTIVE: To provide a qualitative examination of the service and support needs of children who have had a mild traumatic brain injury (mTBI), and their parents, in order to improve clinical services. METHODS: Semi-structured interviews were conducted with 9 children (8-12 years; M = 10.6 years, SD = 0.8) and their parents (n = 9) 29-55 days (M = 34 days; SD = 9.3) after presenting to an Australian Paediatric Emergency Department (PED) for mTBI. Children's post-concussive symptoms (PCS) were additionally measured using the Post-Concussive Symptom Inventory (PCSI). Audio recordings were transcribed, and a thematic analysis was conducted. RESULTS: Post-injury needs were reflected in four main themes: Communication; Family Burden; Continuity of Care; and Social and Community Support. These themes reflected children's and parents' needs for information, emotional/social/community support, and follow-up care. Both the children's and parents' needs, and the extent to which they were met, appeared to be related to the severity and duration of the child's PCS. CONCLUSIONS: Dedicated pediatric mTBI follow-up services that build on family's resources and meet their individual needs for information, emotional support, and referral may assist in optimizing post-injury outcomes.

Further investigation of the use of dimethyl methylphosphonate as a 31P-NMR probe of red cell volume.

We have refined a method for measuring erythrocyte volume using the 31P-NMR spectrum of a probe molecule, dimethyl methylphosphonate. This compound, when added to an erythrocyte suspension, gives rise to two 31P-NMR resonances, and the frequency separation between them is linearly dependent on the intracellular haemoglobin concentration. If, for a given cell sample (under standard conditions), the separation of the two dimethyl methylphosphonate peaks has been measured and an independent estimation of the mean cell haemoglobin content and concentration has been obtained, then changes in the mean cell volume due to altered experimental conditions may be estimated from the peak separation measured under the new conditions. Although the peak separation was independent of extracellular pH, it did vary with (i) a range of extracellular suspension media, (ii) temperature, (iii) dimethyl methylphosphonate concentration, (iv) haemoglobin ligand state and (v) different blood donors.

Intracellular pH in stored erythrocytes. Refinement and further characterisation of the 31P-NMR methylphosphonate procedure.

Methylphosphonate in conjunction with 31P-NMR spectroscopy was used for the measurement of transmembrane delta pH in human erythrocytes stored at 4 degrees C for up to 5 weeks in a nutrient medium. Intra- and extracellular pH was determined using calibration curves based on the pH-dependent separation between the NMR resonances of methylphosphonate and orthophosphate (Pi). A comprehensive statistical procedure is presented for the determination of the variance of NMR-based pH estimates. The entry of methylphosphonate into erythrocytes was more rapid at low pH and uptake was fully inhibited by the band 3 reagent, disodium 4,4-diisothiocyano-2,2'-disulphonic acid stilbene. The distribution ratio of methylphosphonate concentration inside and outside the cells was used to calculate the membrane potential; the analysis depends on a consideration of the Donnan equilibrium for an anion with one or two charges. Furthermore, the analysis does not depend on the pH estimates but relies solely on concentration estimates. The chemical shift of methylphosphonate was not subject to the variations associated with specific intracellular binding encountered with many other phosphorus compounds, including Pi. On the other hand, the ionic strength dependence of the chemical shift of methylphosphonate, contrary to earlier reports, is comparable in magnitude (but opposite in sign) to that of Pi.

The relationship between glucose concentration and rate of lactate production by human erythrocytes in an open perfusion system.

A thermodynamically open system, based on an assembly of capillaries with semi-permeable walls was constructed in order to study glycolysis in human erythrocytes in high haematocrit suspensions. A phenomenological expression for the rate of lactate production as a function of glucose concentration was obtained. The rate was measured under steady-state conditions with low substrate concentrations (approx. 50 mumol/l). In a corresponding closed system, this concentration of glucose would be exhausted within a few minutes. A mathematical model of the whole system consisted of five differential equations, and involved parameters relating to flow rates, volumes of reaction chambers, the rates of lactate efflux from erythrocytes and the expression for the rate of lactate production by red cells. The binding of [14C]pyruvate to haemoglobin and the rate of efflux of [14C]lactate from red cells were measured to yield additional information for the model. The concentrations of ATP and 2,3-bisphosphoglycerate were measured during the perfusion experiments, and a detailed analysis of a model of red cell hexokinase was carried out; the former two compounds inhibit hexokinase and alter the apparent Km and Vmax for glucose in vivo. These steady-state parameters were similar to the glucose concentration at the half-maximal rate of lactate production and the maximal rate, respectively. These findings are consistent with the known high control-strength for hexokinase in glycolysis in human red cells. The practical and theoretical validation of this perfusion system indicates that it will be valuable for NMR-based studies of red cell metabolism using a flow-cell in the spectrometer.

Evaluation of an electrochemical model of erythrocyte pH buffering using 31P nuclear magnetic resonance data.

When erythrocytes are suspended in a solution of known composition the resultant values of such basic cell parameters as volume and pH are difficult to predict. To facilitate such predictions, we developed a mathematical model describing the passive transmembrane distribution of permeant species; three simultaneous equations were produced. Certain essential data required for the model were determined experimentally; these included the pH dependence of the charge on the hemoglobin molecule and the variation of the osmotic coefficient of hemoglobin with cell volume. Finally, cells were added to various solutions, and then titrated to produce a wide pH range (pH 6-8). We measured the resultant cell volume, cellular and extracellular pH using both conventional and 31P NMR methods. The expected equilibrium values of these electrochemical parameters were also calculated by solving (numerically) the three model equations. The accuracy of the model simulations was evaluated by direct comparison of calculated and experimentally determined values.

The difficult hypertensive.

With the wide range of medications available today it should be possible to obtain satisfactory control in the majority of hypertensive patients. However, there are various categories of patients who may present particular problems in management, as for example patients with cerebro-vascular and coronary disease, or with renal failure. A particularly important group is those presenting with severe resistant hypertension, and these patients may constitute about 5 to 10% of the hypertensive population. Considerations relevant to the management of patients presenting with such problems are discussed. Combined drug regimens employing clonidine or beta-blockers with peripheral vasodilators appear to be particularly useful.

Supernatant hemoglobin determinations after prolonged blood storage.

Measurement of extracellular hemoglobin is useful for assessing the relative success of different blood storage strategies. The test is now also included in routine quality assurance procedures. With the recent trend towards transfusion of concentrated red cells resuspended in "additive" solutions, a safe and efficient method for the estimation of hemoglobin in these units is required. We have developed a method suitable for this purpose, based on the formation of cyanomethemoglobin. Tetramethylbenzidine (TMB) methods were also investigated and shown to detect hemoglobin and hemoglobin derivatives quantitatively when present in packed cell supernatants. A close correlation was recorded between the estimates of supernatant hemoglobin using the 2 techniques with 68 stored red cell concentrates. Because of its simplicity, adequate sensitivity and avoidance of carcinogenic benzidine derivatives, we recommend the cyanomethemoglobin method for routine use in the measurement of supernatant hemoglobin in stored modified red cell concentrates.

Red cells suspended in a phosphate-fortified additive: biochemical enhancement and longer storage.

When compared to our current storage regime, an additive solution, with 75 mM inorganic phosphate, improved certain biochemical and morphological parameters measured in suspensions of packed red cells throughout 49 days of liquid storage. In particular, the mean ATP level of 20 donations stored with the high phosphate additive was consistently and significantly higher than in standard (n = 6) suspensions. The increased amount of inorganic phosphate and the higher pH of the new additive stimulated ATP production and provided better pH buffering than the standard solution currently in use. Although survival study results indicated adequate 24h survivals for erythrocytes stored for 42 days with the new solution, after 49 days storage, the mean 24h survival of autologous erythrocytes was only 58 +/- 7% (n = 6).

A young man with hyperimmunoglobulin-E syndrome and IgA and IgG deficiencies.

Hyperimmunoglobulin E syndrome (HIES) with recurrent infection is a rare primary immunodeficiency characterized by the clinical triad of recurrent staphylococcal abscesses, cyst-forming pneumonia and an elevated serum immunoglobulin (Ig)E level. We report an 18-year-old man with recurrent chest infections, skin infections and dermatitis. On examination, he had the characteristic facies of HIES: high arched palate, webbing between his thumb and index finger bilaterally, and extensive scarring from multiple staphylococcal skin abscesses. He had an elevated IgE level of 14 300 kU/L. IgA and IgG deficiencies were also identified, which are rare associations of this syndrome and complicated the patient's treatment. The coexistence of HIES, IgA and IgG deficiencies has, to our knowledge, not been reported previously in the literature.

Verapamil in the long-term treatment of angina pectoris.

A long-term, open clinical trial of verapamil therapy was conducted in 93 patients with coronary artery disease, selected on the basis of having stable angina pectoris and of being unsuitable for treatment with beta-adrenergic blocking drugs. Two-thirds of the patients (58 patients) obtained a good relief which was sustained over a period of one year. There were few major adverse reactions, and the drug was generally well tolerated. The main limiting factor in dosage was hypotension. No adverse effects were observed in patients with obstructive airways disease, controlled cardiac failure, and lower limb arteriosclerosis. Verapamil was considered to be a major advance in the chronic therapy of angina pectoris.

Verapamil in the long-term treatment of angina pectoris.

1. A long-term, open clinical trial of verapamil therapy was conducted in ninety-three patients with coronary artery disease, selected on the basis of having stable angina pectoris and of being unsuitable for treatment with beta-adrenoceptor blocking drugs. 2. Two-thirds of the patients (fifty-eight patients) obtained a good relief which was sustained over a period of 1 y. There were few major adverse reactions and the drug was generally well tolerated. The main limiting factor in dosage was hypotension. No adverse effects were observed in patients with obstructive airways disease, controlled cardiac failure and lower limb arteriosclerosis. 3. Verapamil was considered to be a major advance in the chronic therapy of angina pectoris.

Survival after trauma--experience at an acute-care general hospital.

OBJECTIVE: To assess the effectiveness of the management of acute traumatic illness at an acute-care general hospital. DESIGN: The study was conducted prospectively for the calendar year 1989. The Trauma Score (TS) and the revised Trauma Score (RTS) were calculated on arrival at hospital. These clinical indices were used, with the Injury Severity Score (ISS) and the age, to predict the probability of survival (Ps) and the probability of mortality. The predicted probabilities were compared with the probabilities of survival and mortality derived from a recognised baseline. SETTING: The Trauma Service of The Sutherland Hospital Caringbah, including the Emergency and Intensive Care Departments and the Departments of Surgery and Anaesthetics. PATIENTS: 74 patients of all ages who were brought to the Emergency Department because of acute traumatic illness with an ISS greater than 16. Only patients with signs of life on arrival were included in the study group. Data were complete in all 74 patients. RESULTS: There were 60 survivors and 14 deaths compared to figures predicted using data from the baseline group of 52.6 survivors and 21.4 deaths. There were no preventable deaths. There were five survivors whose probability of survival was less than 0.50. Three cases of late diagnosis were noted; the late diagnoses did not significantly affect the outcomes--they occurred because specialist assessment was delayed. CONCLUSIONS: It is possible, with few resources, to quantitatively and qualitatively assess the effectiveness of a trauma care service.

Emergency management skills of South Australian paediatric trainees.

OBJECTIVE: This article describes a theoretical and practical assessment of the emergency management skills of South Australian paediatric trainees. The aim was to identify strengths and weaknesses so as to optimally orientate future training in this area, and to provide a baseline that could be used to assess effectiveness of future interventions. METHODOLOGY: Thirty-four paediatric trainee medical officers responsible for after hours emergency care in Adelaide were asked to anonymously complete a 24 question theory assessment based on recognized emergency management training programmes, and to perform a mock clinical resuscitation. Response rate was 90% for the theoretical section and 69% for the practical. RESULTS: The average trainee was found to be deficient in one quarter to one third of the theoretical precepts, and required an average of 2 min to establish effective bag-valve-mask ventilation with an infant manikin. CONCLUSIONS: There is a range of theoretical and practical resuscitation deficits that may currently hinder effective emergency management by paediatric trainees.

Effect of intracellular magnesium on calcium extrusion by the plasma membrane calcium pump of intact human red cells.

1. The effect of varying the concentration of intracellular magnesium on the Ca(2+)-saturated Ca(2+)-extrusion rate through the Ca2+ pump (phi max) was investigated in human red blood cells with the aid of the divalent cation ionophore A23187. The aim was to characterize the [Mg2+]i dependence of the Ca2+ pump in the intact cell. 2. The initial experimental protocol consisted of applying a high ionophore concentration to obtain rapid sequential Mg2+ and [45Ca]CaCl2 equilibration, prior to measuring phi max at constant internal [MgT]i by either the Co2+ block method or by ionophore removal. With this protocol, competition between Ca2+ and Mg2+ through the ionophore prevented Ca2+ equilibration at high [Mg2+]o. To provide rapid and comparable Ca2+ loads and maintain intracellular ATP within normal levels it was necessary to separate the Mg2+ and the Ca2+ loading-extrusion stages by an intermediate ionophore and external Mg2+ removal step, and to use different metabolic substrates during Mg2+ loading (glucose) and Ca2+ loading-extrusion (inosine) periods. 3. Intracellular Co2+ was found to sustain Ca2+ extrusion by the pump at subphysiological [Mg2+]i. Ionophore removal was therefore used to estimate the [Mg2+]i dependence of the pump at levels below [MgT]i (approximately 2 mmol (340 g Hb)-1), whereas both ionophore removal and Co2+ block were used for higher [MgT]i levels. 4. [Mg2+]i was computed from measured [MgT]i using known cytoplasmic Mg(2+)-buffering data. The phi max of the Ca2+ pump increased hyperbolically with [Mg2+]i. The Michaelis parameter (K 1/2) of activation was 0.12 +/- 0.04 mmol (1 cell water)-1 (mean +/- S.E.M.). Increasing [MgT]i and [Mg2+]i to 9 mmol (340 g Hb)-1 and 2.6 mmol (1 cell water)-1, respectively, failed to cause significant inhibition of the phi max of the Ca2+ pump. 5. The results suggest that within the physiological and pathophysiological range of [Mg2+]i, from 0.3 mmol (1 cell water)-1 in the oxygenated state to 1.2 mmol (1 cell water)-1 in the deoxygenated state, the Ca(2+)-saturated Ca2+ pump remains unaffected by [Mg2+]i at normal ATP levels.

Goitre causing acute respiratory arrest.

A patient reported symptoms of upper airway obstruction for 4 years. His symptoms worsened with a viral upper respiratory infection and he suffered acute respiratory arrest. He was resuscitated and a large goitre with intrathoracic extension which was compressing the trachea was resected. The mechanisms of upper airway compromise by goitre are discussed. The symptoms of the effect of goitre on the airway are reviewed.

The formation and regression of synapses during the re-innervation of axolotl striated muscles.

1. A study has been made of the formation and regression of synapses formed by spinal nerves 16 and 17 in axolotl hind-limb flexor muscles following the severing of nerve 16, using histological, ultrastructural and electrophysiological techniques. 2. Axolotl hind-limb flexor myofibres possessed 'en plaque' end-plates from either spinal nerve 16 or 17 or both at intervals of about 1000 micronm along their length; the myofibre's length constant was about 700 micronm allowing electrophysiological observations of at least two of these synapses during a single impalement; transmitter release at these synapses could be described by binomial statistics and in a given set of ionic conditions the binomial statistic parameter n was directly proportional to the size of the nerve terminals whilst the binomial statistic parameter p was invariant to changes in nerve terminal size. 3. The distribution of synapses formed by spinal nerves 16 and 17 in different sectors of the axolotl hind-limb flexor muscles was determined from a study of evoked end-plate potentials; the middle and proximal sectors of the flexor muscles contained myofibres which received an innervation from nerve 16 only, whereas the sectors surrounding these contained myofibres innervated either by nerve 16 or nerve 17 or by both nerves. 4. Six days following the severing of spinal nerve 16, evoked transmitter release from the synapses formed by this nerve had failed; transmission was subsequently recorded at a few synapses formed by nerve 17 in the middle and proximal sectors of the flexor muscles which are not normally innervated by this nerve and these synapses had a low n; during the succeeding four weeks the value of n at the synapses increased to a size about 70% that of the terminals normally formed by nerve 16 at these sites. 5. Four weeks after severing nerve 16, myofibres which possessed synapses formed by nerve 17 also possessed synapses from re-innervating nerve 16 and these were sometimes formed at the same synaptic sites as those occupied by nerve 17. 6. In the subsequent sixteen weeks, the n value of synapses formed by nerve 17 declined whilst the n values of synapses formed by re-innervating nerve 16 on the same myofibres matured to their control size. 7. It is suggested that on severing nerve 16 collateral sprouting of nearby intact nerve 17 occurs and these collateral sprouts innervate the denervated synaptic sites, although the sprouts arenot as well matched to the denervated synaptic sites as are the original nerve terminals; thus if nerve 16 returns it preferentially forms synapses at its original synaptic sites, and the collateral synapses formed by nerve 17 regress.

Factors influencing the presentation and care of elderly people in the emergency department.

OBJECTIVE: To provide Australian data from a community setting on the use of the Emergency Department by elderly persons. DESIGN: The paper describes three studies. Study 1 analyses patient admission patterns, and clinical data taken retrospectively from medical records for 1987. Studies 2 and 3 prospectively survey referral, transport, demographic profiles and clinical management practices in two patient samples taken during 1987 and 1988. SETTING: The Emergency Department of Sutherland Hospital, Sydney--a community based hospital of 374 beds. PATIENTS: In study 1, we assessed 4609 hospital admissions of patients aged 60 years or more using ICD-9-CM coding. In Studies 2 and 3, samples of 74 patients aged 65 years or more and 100 patients aged 70 years or more who presented to the Emergency Department were assessed consecutively and prospectively. INTERVENTIONS: No specific interventions outside of usual Emergency Department routines were undertaken except for collection of demographic data. MAIN OUTCOME MEASURES: Demographic characteristics, diagnostic categories, and referral, admissions and hospital separation data. RESULTS: In Study 1, of 4609 patients aged 60 years or more 3182 (69%) entered hospital via the Emergency Department. These 3182 represented 29% of total hospital admissions for that year. In Study 2 the male to female ratio was 32 to 42; the mean age was 78.16 years; 88% were pensioners; 20% had additional private insurance; 76% of women were widowed compared with 32% of men; 84% of the group lived in their own homes but, of these, 51% of women lived alone compared with 7.7% of men. The disease profile was that of acute organic disease in 97% of presentations. Ambulance transport to the Emergency Department was used by 65% of patients and Emergency Department facilities were used mostly during "working hours"; 64% of patients were admitted to hospital. The pre-hospital "activities of daily living" (ADL) functioning was assessed as being independent in 85%. In Study 3, the social and demographic profile was similar to Study 2. Fifty seven of the 100 patients used ambulance transport to the Emergency Department and this was initiated by a general practitioner in 13 instances. The general practitioner was the referring source in 28% of cases. Waiting times in the Emergency Department demonstrated a mean time from arrival to assessment by a medical officer of 30 minutes and a total time spent in the Emergency Department of 3 hours 4 minutes for those discharged home and 4 hours 24 minutes for those admitted. CONCLUSION: These studies demonstrate that the Emergency Department is a major area for care of the elderly and entry into the hospital system. Referral from a general practitioner and the use of ambulance transport from home to the Emergency Department are frequent pathways of care that may have important cost-benefit implications and deserve further study. The elderly in these studies appear to use the Emergency Department appropriately for acute medical/surgical need. The social profiles suggest that widowed women present a special case in terms of discharge plans for management.

Measurement of the distribution of anion exchange function in normal human red cells.

1. The aim of the present work was to investigate cell-to-cell variation in anion exchange turnover in normal human red cells. Red cells permeabilized to protons and K+ dehydrate extremely rapidly by processes that are rate-limited by the induced K+ permeability or by anion exchange turnover. Conditions were designed to render dehydration rate-limited by anion exchange turnover. Cell-to-cell variation in anion exchange function could then be measured from the distribution of delay times required for dehydrating cells to attain resistance to haemolysis in a selected hypotonic medium. 2. Red cells were suspended at 10% haematocrit in a low-K+ solution and, after a brief preincubation with 20 microM SITS at 4 degrees C, were warmed to 24 degrees C, and the protonophore CCCP was added (20 microM) followed 2 min later by valinomycin (60 microM). Delay times for cells to become resistant to lysis were measured from the instant of valinomycin addition by sampling suspension aliquots into thirty volumes of 35 mM NaCl. After centrifugation the per cent lysis was estimated by measuring the haemoglobin concentration in the supernatant. Typical median delay times with this standardized method were 4-5 min. 3. The statistical parameters of the delay time distributions report the population spread in the transport function that was limiting to dehydration. In the absence of SITS and CCCP, dehydration was limited by the diffusional Cl- permeability (PCl). Delay time distributions for PCl- and anion exchange-limited dehydration were measured in red cells from three normal donors. For both distributions, the coefficients of variation ranged between 13.0 and 15.2%, indicating a high degree of uniformity in PCl and anion exchange function among individual red cells.

An epidemiological survey of dog bites presenting to the emergency department of a children's hospital.

German shepherds are the most popular registered breed of dog in South Australia, but are also the most hazardous to children, biting more often and more severely. A study of the victims of dog bites presenting to the Emergency Department of the Adelaide Children's Hospital over an 18 month period revealed that, although many breeds were involved, only German shepherds were implicated more frequently than their prevalence in the community. Attacks occurred most often in a domestic setting involving a friendly dog that was known to the victim. Boys were more often bitten than girls and children aged 1-6 years most commonly involved. Injuries to the face and scalp were frequent and the usual ones to require admission for suture under general anaesthetic. Some scarring was a common sequel and resulting fear of dogs remained with some children. Most attacks were reported to be unprovoked and a previous biting history on the part of the dog was uncommon. Parents who are contemplating obtaining a dog for a family pet should be made aware of these facts and advised regarding the biting hazards and possible prevention. The German shepherd situation especially should be brought to their attention.