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Biomedical subjects

R F Armstrong

Publications and source records attributed to R F Armstrong.

At least 19 recordsLinked to original sources

Epidural and spinal anaesthesia and the use of anticoagulants.

Neurological injuries after epidural/spinal analgesia are a serious but uncommon problem. Spinal haematoma cause a proportion of these complications, and can be minimized by avoiding central nervous blockade in high-risk patients, especially those receiving anticoagulant therapy. Early recognition of spinal haematoma by basic neurological monitoring allows early intervention and improves outcome.

Anesthesia, Epidural↗

Endoreduplication and telomeric association in a choroid plexus carcinoma.

Cytogenetic studies showed a hyperhaploid stemline, (32,XY,+1,+7,+9,+12,+13,+14,+19,+20) in a patient with choroid plexus carcinoma. Endoreduplication and doubling of the stemline to 200-400 chromosomes per cell and variation in numerical changes were also noted. Telomeric association was present in most cells. The 12p and 20q were by far the most frequently involved chromosome arms. Telomeric association is believed to have triggered further structural changes in this case since the 12p and 20q were always involved in the few structural abnormalities identified. A review of the literature suggests that hyperhaploidy may characterize choroid plexus carcinoma and hyperdiploidy choroid plexus papilloma.

Choroid Plexus Neoplasms↗

Cytogenetic evidence that a tumor suppressor gene in the long arm of chromosome 1 contributes to glioma growth.

In a patient with a rare subtype of glioma, pleomorphic xanthoastrocytoma, cytogenetic studies revealed that both homologues of chromosome 1 were involved in translocations at the same band 1q42 but with different partner chromosomes. In addition, 5 glioblastomas out of 25 gliomas karyotyped in our laboratory had lost at least one copy of band 1q42 through deletions, unbalanced rearrangements, or chromosome losses. Twenty-one gliomas that had lost at least one copy of chromosome band 1q42 were identified in the literature; all were astrocytic tumors and the majority were glioblastomas. It indicates a covert tumor suppressor gene in the region that is involved in astrocytic gliomas.

Chromosome Aberrations↗

An audit programme for central venous catheter-associated infections.

Central venous catheters (CVC) are commonly associated with both localized and systemic infection. This paper describes an audit programme which was designed to review clinical practice associated with the insertion and subsequent care of CVC and their possible relationship to the development of infection. The programme was produced by a joint working group of the Hospital Infection Society and the Research Unit of the Royal College of Physicians and is subdivided into an audit of hospital practices and patient management associated with the use of CVC. It consists of a number of questions designed to evaluate all areas of CVC use, including the assessment of the incidence of associated local and systemic infection. Use of the questionnaire should allow policies for CVC insertion and care to be reviewed thereby, facilitating improvements, which may in turn reduce the incidence of infection associated with CVC.

Catheterization, Central Venous↗

The cost of intensive care: a comparison on one unit between 1988 and 1991.

OBJECTIVE: To assess the changes in cost of intensive care in one unit after a 3 year period and to evaluate the relative costs of an integrated high dependency unit. DESIGN: Combined retrospective and prospective audit of all expenditure incurred in an intensive care/high dependency unit over two periods: April 1988-February 1989 and January-July 1991. SETTING: Combined 13-bedded intensive care/high dependency unit of a central London teaching hospital. RESULTS: The overall cost rose by 50%. Hidden costs such as infrastructure maintenance, capital assets, pathology and radiology services accounted for nearly a quarter of total expenditure. Pharmacy and supplies each accounted for some 10% of total expenditure whereas staff costs exceeded 50%. The cost of the intensive care section rose by 14% of 1149 pounds per patient day as increased bed occupancy offset increases in nurse: patient ratios and expenditure on consumables. However, the cost of the high dependency unit section rose by 87% to 437.83 pounds. This was due to a lower bed occupancy (through increased patient turnover), improved staffing ratios, and increased utilisation of equipment and supplies. CONCLUSIONS: Intensive care is an increasingly expensive speciality, the costs for which are rising over and above the rate of general inflation. Staff costs are by far the largest single item of expenditure. Large reductions in spending on drugs and consumables are unlikely to provide considerable savings on the total budget. Hidden costs account for a high proportion of the budget and should be taken into account when evaluating cost. The significantly lower cost of high dependency care should encourage studies into its cost-effectiveness.

Health Services Research↗

Guidelines for good practice in central venous catheterization. Hospital Infection Society and the Research Unit of the Royal College of Physicians.

Central venous catheters (CVC) are commonly used in clinical practice and are associated with several complications, including early and late onset infection. In these guidelines, an outline of good practice for the use of CVC and the prevention of associated infections is presented. Definitions of both localized and systemic catheter-related sepsis are given. Subsequent good practice in relation to the insertion of CVC, including patient preparation, planned duration of catheterization, catheter materials and design of the CVC, are presented. Skin fixation and insertion site care, including the use of dressings and administration sets, as well as an approach to flow obstructions, are also reviewed. The clinical and microbiological diagnosis of catheter-related sepsis and its treatment is next presented. Finally, guidelines for CVC removal and replacement are given. The guidelines are designed to facilitate the development of good practice in the use of CVC, allowing appropriate protocols to be formulated and to reduce infection risk.

Bacteremia↗

Long term effects of smoke inhalation in survivors of the King's Cross underground station fire.

BACKGROUND: In most accidents causing smoke inhalation only a few victims actually inhale the smoke. The fire at King's Cross provided an opportunity to assess the long term effects of smoke inhalation in a larger number of patients. METHODS: Fourteen survivors from the King's Cross underground station fire were assessed for respiratory disability six months after the disaster and 10 were reassessed at two years. All had inhaled substantial quantities of smoke and 10 had skin burns of differing severity. RESULTS: Six months after the fire nine survivors admitted to one or more symptoms, which included hoarseness (two cases), cough (five cases), and breathlessness (six cases); and a survivor with asthma noted a worsening of his symptoms. The remaining five denied new symptoms. Peak expiratory flow, spirometric indices, and transfer factor for carbon monoxide were within the predicted normal ranges. The mean residual volume, however, was greater than the predicted value and the mean maximum expiratory flow at 25% of vital capacity (V25) less than predicted, with no significant differences between smokers (n = 7) and non-smokers (n = 7). At least one of these ventilatory defects, suggesting small airways obstruction, was present in 11 survivors at six months and they had persisted in the seven patients who were reassessed at two years. CONCLUSION: Smoke inhalation may be associated with injury to the small airways.

Adult↗

Fluid requirements of patients with burns and inhalation injuries in an intensive care unit.

We have studied 9 patients with burns (20%-75%) who had inhalation injuries and compared their actual fluid requirements with their requirements calculated from the Muir and Barclay formula. All patients were resuscitated with plasma protein fraction at a rate sufficient to keep their physiological variables within the following range: heart rate less than 120/min, central venous pressure 8-12 cm H2O, urine output greater than 30-50 ml/h, systolic blood pressure greater than 90 mm Hg and diastolic blood pressure greater than 60 mm Hg. The amount of plasma protein fraction needed was 4.38 +/- 1.26 ml/kg/% burn in the first 24 h and 2.15 +/- 0.97 ml/kg/% burn in the second 24 h. This is an increase of 75% and 110% respectively above values predicted from the formula. We suggest that the observed difference is due to a combination of the presence of an inhalation injury which increases fluid requirements by approximately 30% in the first 24 h and the use of plasma protein fraction rather than the dried plasma used in the original Muir and Barclay formula.

Adult↗

Jugular venous bulb catheterization in infants and children.

Cross-brain oxygen extraction may be altered by coma, hyperventilation, hypothermia, or barbiturates, and has been demonstrated in adults and more recently in children to be related to functional neurologic recovery after a variety of brain injuries. However, measurement of cross-brain oxygen extraction in children is currently not a part of routine clinical care, partly because there have been no published attempts relating the technique of jugular venous bulb (JVB) catheterization and its complication in children. We catheterized the JVB to measure cerebral venous oxygen content and calculate cross-brain oxygen extraction in 26 deeply comatose neonates and children ranging in age from a few hours to 14 yr. Bedside catheterization using the Seldinger technique was successful in 25 children, with standard venous cutdown necessary in the remaining child. All JVB catheterizations were performed with parental consent and during continuous monitoring of the intracranial (ICP) or fontanelle, as well as arterial, pressure. ICP was not significantly altered by the cannulation procedure in any of the children studied, although the cannulation occurred early in the child's course when ICP was well controlled. Inadvertent carotid artery puncture with bleeding controlled by local pressure occurred in four children, and catheter malposition was confirmed on lateral skull xray in two others. Jugular venous bulb catheters remained in place for 2 to 7 days (average 3) and malfunction or obstruction of the catheter did not occur. Organisms were grown from three of 26 catheter tips submitted for culture, with peripheral blood cultures also positive for the same organisms in two of these.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗