Prescribing in the prehospital environment: a review of the pharmaceutical Module 501 on UK Military Exercise SAIF SAREEA 3. Can such analysis assist with the scaling of healthcare assets?

INTRODUCTION

Module 501 provides core medications which are fundamental to the capability of a prehospital treatment team (PHTT). The quantities of each medication in the module inventory undergo regular review, but these do not correspond to a population at risk (PAR) figure or deployment length for which they intend to be used. This article proposes how the quantities of Module 501 drugs can be scaled for a given deployment, in this example using statistics taken from static PHTTs on Exercise Saif Sareea 3 (SS3).

METHODS

The statistics were gathered using a custom-built search of electronic records from the Deployed Defence Medical Information Capability Programme in addition to written record-keeping, which were aligned to the weekly PAR at each PHTT location throughout their full operational capability periods. A quotient was then derived for each module item using a formula.

RESULTS

Among the 10 most commonly prescribed drugs were four analgesics and three antimicrobials. 42 of the 110 studied drugs were not prescribed during SS3.

DISCUSSION

The data from SS3 reflect the typical scope of disease encountered in the deployed land setting. Employing these data, the use of a formula to estimate the drug quantities needed to sustain a Strike Armoured Infantry Brigade over a 28-day period is demonstrated.

RECOMMENDATIONS

Further study of Module 501 across varied deployment environments would be valuable in evolving this approach to medicinal scaling if proven effective for the warm desert climate. It could then be applied to other modules to further inform future Strike medical planning.

LIMITATIONS

Several considerations when drawing deductions from the data are mentioned, including the inaccuracy of predictor variables taken from the EpiNATO-2 reports.

CONCLUSION

The proposed formula provides an evidence-based framework for scaling drug quantities for a deployment planning. This may improve patient safety and confer logistical, storage and fiscal benefits.

Sample size determination for a t test given a t value from a previous study: A FORTRAN 77 program

When uncertain about the magnitude of an effect, researchers commonly substitute in the standard sample-size-determination formula an estimate of effect size derived from a previous experiment. A problem with this approach is that the traditional sample-size-determination formula was not designed to deal with the uncertainty inherent in an effect-size estimate. Consequently, estimate-substitution in the traditional sample-size-determination formula can lead to a substantial loss of power. A method of sample-size determination designed to handle uncertainty in effect-size estimates is described. The procedure uses the t value and sample size from a previous study, which might be a pilot study or a related study in the same area, to establish a distribution of probable effect sizes. The sample size to be employed in the new study is that which supplies an expected power of the desired amount over the distribution of probable effect sizes. A FORTRAN 77 program is presented that permits swift calculation of sample size for a variety of t tests, including independent t tests, related t tests, t tests of correlation coefficients, and t tests of multiple regression b coefficients.

An on-line exact small-sample test of significance for extended matching tasks

An extension of the traditional matching paradigm that enables researchers to test a variety of new experimental hypotheses is outlined. An on-line computer program that provides an exact small-sample test of hypotheses in the extended matching paradigm is described. The program, which has an intuitive graphical interface, may be accessed and executed via the Internet by using an ordinary browser.

Testing hypotheses about working memory capacity

When an individual is engaged in sampling from a finite population, an assessment of their working memory for previously sampled objects is often desired. An extension of the classical occupancy distribution provides a framework for testing hypotheses about working memory capacity, based on a general model of working memory in which the individual retains a record of m previous inspections (and hence does not make the mistake of resampling these objects) and samples with replacement objects outside the current memory set. The buffer size m provides a common metric for assessing the effect of variables on performance in search tasks involving different numbers of items, or locations.

Problems in the diagnosis of pituitary adenoma (Cushing's syndrome) in horses

Thyrotropin releasing hormone (TRH) stimulation tests were carried out on a number of horses, including one clinically affected horse whose age and clinical signs suggested that a pituitary adenoma was most unlikely. The results of these tests indicated that, according to criteria published overseas, the majority of these horses had pituitary adenomas. The fact that clinically normal or affected horses may have marked increases in cortisol concentrations indicates that the TRH stimulation test is not suitable for the diagnosis of pituitary adenoma. Other tests, including alterations in glucose metabolism and, if available, ACTH measurements, are probably more useful for diagnosis. However, most diagnoses will probably rely upon the characteristic clinical signs.

Choice autonomy and memory for spatial locations in six-year-old children

Six-year-old children were presented with 12 identically labelled locations in a room and required to search non-redundantly for the six that contained rewards. On each day they could commit Across-Trial Memory (ATM) errors by visiting non-rewarded locations, or Within-Trial Memory (WTM) errors by revisiting locations previously visited that day. Groups were trained for nine days, either walking or pushed in a wheelchair, and with or without freedom of choice. They were then tested, walking with freedom of choice. Performance of the task improved significantly across training days in groups allowed free choice, whether walking or transported, and was superior at test to that of non-choosing groups. Throughout training and testing, the ATM component of performance was superior in groups allowed free choice. WTM was more accurate than would be expected by chance in all subjects at all stages of the experiment, but did not differ between groups. The problem of comparing WTM scores in groups differing in ATM accuracy was discussed. It was concluded that the primary benefit of free choice in spatial memory tasks is that it promotes accurate environmental segmentation, and that WTM is little affected by training or environmental familiarity.

Prescriptions for medical research. I--Management within the Medical Research Council

In their submission to the government in advance of the white paper on science policy in the United Kingdom the Medical Research Council commends the MRC's own approach to managing directly funded research. But a series of semi-structured interviews with the directors of some of the MRC's units suggests a gap between the MRC's model of managed research and the reality. Although such units are theoretically managed from MRC head office (and units are charged an overhead for this), in practice each unit runs its own affairs. Between major reviews average contact time with the head office contact person is seven hours a year. The first paper argues that a purchaser-provider split would recognise the benefits of decentralisation and allow units to bid for research funds from several sources, the successful ones guaranteeing their survival through a rolling series of research programmes. The second paper criticises the MRC's cumbersome peer review system. Reliance on outside experts atrophies the scientific skills of head office staff and builds delays into decision making. A purchaser-provider model would allow the head office scientific staff to act like commercial research and development managers, commissioning research, and using the outcome, rather than peer review, as a criterion for continued funding.

The nature of the inflammatory infiltrates in childhood gingivitis, juvenile periodontitis and adult periodontitis: immunocytochemical studies using a monoclonal antibody to HLADr

Routinely fixed and processed gingival biopsies from childhood gingivitis, juvenile periodontitis and chronic adult periodontitis patients have been stained immunocytochemically with a monoclonal anti HLADr antibody to aid in the identification and quantification of cell types in the inflammatory infiltrates. Using immunoperoxidase staining and morphological criteria, 9 cell types were quantified in 30 patients. Lesions in the 3 groups were found to differ widely both in size and composition. In the small childhood gingivitis lesions, most cells were small lymphocytes, over half of which were HLADr positive, whereas in juvenile periodontitis biopsies, well over half the infiltrate was plasma cells. The chronic adult periodontitis samples showed greater variability in composition between these 2 extremes, perhaps reflecting differences in disease activity. These results suggest that, when disease is quiescent, the volume of inflamed gingival connective tissue is small and is dominated by B-small lymphocytes, whilst on activation, the lesion increases in size and much of the B-lymphocyte population is transformed to plasma cells. This view corroborates the results of other workers with regard to juvenile periodontitis, but suggests a different interpretation of the quiescent lesion of childhood gingivitis from that current in the literature.

An ultrastructural and enzyme cytochemical study of the response of the neutrophil series to a local inflammatory stimulus in the rat

Changes in neutrophil precursor populations in the bone marrow and their alkaline phosphatase reactivity following an inflammatory stimulus were studied in the rat using an osmiophilic method. Seven groups each of 3 Sprague-Dawley rats received subcutaneous injections of turpentine, and femoral marrow was examined at intervals up to 72 hr. Depletion of mature neutrophils resulted in an increased first in the myeloblast-promyelocyte compartment and at 48-72 hr in the myelocyte-metamyelocyte population. By 72 hr replenishment of the mature neutrophil marrow population had begun. Within 6 hr marked acceleration of cytoplasmic maturation was evident, together with accelerated synthetic activity, manifested by marked dilatation of the rough endoplasmic reticulum and an enlarged Golgi. Together with these changes there was an increase in the number of alkaline phosphatase reactive cells, which was evident first in the myeloblast-promyelocyte population at 2 hr. An absolute increase in the amount of enzyme reaction product associated with individual cells was also seen.

Bacterial invasion of the periodontium in a case of juvenile periodontitis

A case of juvenile periodontitis is described where biopsy material taken from a lower right incisor during periodontal surgery revealed plaque-derived bacteria present within the periodontal connective tissue. The gingival connective tissue contained an inflammatory infiltrate which exhibited a profound loss of collagen and was dominated by plasma cells, many of which had a bizarre cytoplasmic morphology, The invading bacteria were morphologically heterogeneous but mainly gram-negative. Some were found in a patchy distribution in the apical margins of the inflammatory infiltrate and more numerous groups of organisms were in the collagenous connective tissue apical to the infiltrated area. Polymorphonuclear neutrophils (PMN) were seen in association with the bacteria and some PMN showed phagocytosis of bacteria without significant degranulation. This is the first description of bacterial penetration of the periodontium in juvenile periodontitis; it is not known how frequently this occurs but it is an interesting finding in a condition where there is known impairment of one branch of the host's defence mechanisms, namely pMN phagocytosis and degranulation.

Benign thyroid inclusions within cervical lymph nodes: an alarming incidental finding

Small clusters of microscopically normal thyroid follicles within cervical lymph nodes are very occasionally encountered during histological examination. We support the view that provided the thyroid gland is not palpable and a technetium thyroid scan is normal, these should be regarded as benign thyroid inclusions and do not represent small metastatic lesions from thyroid carcinoma. We report an example of these inclusions in a cervical lymph node which was removed incidentally during the excision of a branchial cyst in a 25-year-old woman. The inclusion was too small to be noticed macroscopically and consisted of a small aggregation of histologically normal thyroid follicles situated in the subcapsular region of the lymph node.

Scanning electron microscopic observations of the surface of the initial lesion in experimental streptococcal endocarditis in the rabbit

The surfaces of vegetations in the first 24 h after initiation of experimental streptococcal endocarditis in rabbits were examined systematically using the scanning electron microscope (SEM). Most of the observed fields were occupied by amorphous material but with the SEM very small features of interest could be identified. Erythrocytes were more frequent before 6 h and leukocytes were rarely seen. Bacteria were significantly more frequent at 10/15 min and at 20 h. It is suggested that bacteria lodge on the vegetation surface following inoculation and that after a lag phase colonies are formed within the vegetation which reach the surface again at about 20 h.

Light microscope and electron microscope alkaline phosphatase cytochemistry of rat bone marrow leukocytes

An enzyme cytochemical method yielding an osmiophilic reaction product, visible at both the light and electron microscope levels, has been applied to the study of alkaline phosphatase in rat bone marrow cells. The enzyme is present in both eosinophils and, in much smaller amounts, in neutrophils. In both cases it is present on the plasma membrane, and in eosinophils intracellular aggregations of reaction product are also seen. The specific granules in both cell types fail to react and the enzyme is first detectable at the promyelocyte stage. Thus the enzyme is demonstrable before specific granule formation begins in the neutrophil, indicating that they are not a significant site of alkaline phosphatase activity in the rat.

Ultrastructural localization of alkaline phosphatase in rat eosinophil leucocytes

The ultrastructural localization of alkaline phosphatase in eosinophil leucocytes, obtained from experimentally-induced peritoneal exudates in rats, has been studied using an osmiophilic technique with 2-naphthylthiolphosphoryl dichloride as substrate, fast Blue BBN as diazonium salt and postosmication with 1% aqueous osmium tetroxide. With this method identical incubation procedures could be used for both light and electron microscope examination. Eosinophils were the only cells which contained alkaline phosphatase. The enzyme was predominantly associated with the outer surface of the plasma membrane, being present in much lower concentrations in cytoplasmic cisternae. Eosinophil granules only rarely showed reaction product. The plasma membrane location of alkaline phosphatase in eosinophil leucocytes is identical to that recently demonstrated in the human neutrophil.

Differential leucocyte counts: a comparison of results using light and electron microscopy

A method is described for handling leucocytes from an inflammatory peritoneal exudate prior to electron microscopy, which allows differential counts from ultra-thin sections to be made. The results of counts from ultrathin sections, viewed on the electron microscope, are compared with samples from the same cell populations prepared on a cytocentrifuge and counted by light microscopy. The results from several cell populations of widely different compositions show clearly that with suitable care taken over preparation and orientation, ultrathin sections can yield comparable differential counts to those obtained by standard light microscope procedures. Possible sources of error are discussed and the advantages of ultrastructural counting assessed. The method has a wide application wherever accurate differential counts are required from cell suspensions processed for electron microscopy.

Rapid modification of the morphology of cell contact sites during the aggregation of limpet haemocytes

Haemocytes suspended in the blood of the limpet Patella vulgata rapidly form microspikes and aggregate in response to withdrawal from the haemocoel. It has previously been suggested that the contacts between colliding cells in shaken suspension are stabilized by the rapid spreading of participant cells over each other's surfaces by a microspike-dependent process. In this communication we report that an electron-microscopic study of the contacts formed between cells in the early stages of aggregation suggests that intercellular contact elicits a rapid response from the organelles concerned with cell motility. This response leads to the rapid progression of each initial collision through 3 major categories of contact morphology, namely cell body/lamella, lamella/lamella and cell body/cell body. There is a concomitant increase in the area of mutually contacting surface between participating cells. On the basis of these results, a model is constructed for the participation of sub-surface components in the process of cellular aggregation. The sequence of development of contact found between aggregating cells is envisaged to be a consequence of cellular locomotory activities resembling those by which these cells spread on to a solid substrate. Included in this process is an element of intercellular recognition. It is suggested that the involvement of motile elements in cell aggregation is a general feature of aggregating cells. This would permit a re-interpretation of aggregation experiments which show specificity of cell adhesion, for total adhesive interactions between cells would depend not only on the adhesiveness per unit area of contacting cell surface but also on the extent or rate of formation of flat contact areas. The latter element could be regulated by a recognition system between contacting cells independently of the force per unit area which holds the 2 surfaces together.

Hodgkin's disease presenting with hypoadrenalism

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Distilled glutaraldehyde: its use in an improved fixation regime for cell suspensions

A method is described for the sequential fixation of cell suspensions, suitable for use at room or culture temperatures. Though an adequate method for fixing cell suspensions does exist in the literature (Hirsch & Fedorko, 1968), it involves the use of a mixed glutaraldehyde-osmium tetroxide fixative. Since these two components inter-react, this method has many drawbacks. Previously described weaknesses of a sequential fixation regime (Hirsch & Fedorko, 1968; Jones, Yeh & Hirsch, 1972) with glutaraldehyde and osmium tetroxide have been overcome by the use of vacuum distilled glutaraldehyde as the primary fixative. The results, using a mixed glutaraldehyde-osmium tetroxide fixative and using the two components sequentially on a variety of cell types, are compared. The advantages of a sequential fixation made possible by the use of vacuum distilled glutaraldehyde rather than commercial glutaraldehyde are discussed.

The post-mortem diagnosis of influenzal infection by fluorescent IgG, IgA and IgM antibody studies on necropsy blood

Necropsy blood from cases diagnosed as dying from influenza A was examined for specific antibody in the IgG, IgA and IgM fractions and a specific diagnosis of recent infection was made if either IgM or IgA antibody and low titres of IgG antibody were found. By these criteria a diagnostic rate of 77% was found in those cases from whom no virus was isolated. The use of infected cell monolayers grown on polytetrafluoroethylene-coated slides gave a simple method of carrying out these antibody assays, and the use of necropsy blood did not require any special methods of transport of specimens to the virus laboratory.

Barbiturate blood levels found at necropsy in proven cases of acute barbiturate poisoning

In order to determine whether blood barbiturate levels could be used to ascertain that death had been caused by barbiturate overdose, samples of blood from 128 subjects of coroners' necropsies were examined for barbiturate content. Sixty of these were well authenticated cases of barbiturate overdosage, and barbiturates were implicated, together with other factors such as alcohol and carbon monoxide, in a further 16 cases. The remaining 52 cases were of an eliminatory nature, 10 of which had low barbiturate blood levels considered to be within the therapeutic range.The results indicate that when the accepted levels producing loss of consciousness are exceeded, and maintained, death will ensue if treatment is not given. These results may be of value in assessing findings in necropsies requested by the coroner, and are in no way applicable to the living patient in whom it is well established that recovery from higher blood levels may take place if adequate treatment is available.