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Biomedical subjects

R Laing

Publications and source records attributed to R Laing.

At least 19 recordsLinked to original sources
PubMed1998

Continuous monitoring of cerebrovascular pressure-reactivity in head injury.

OBJECTIVE: Cerebrovascular vasomotor reactivity reflects changes in smooth muscle tone in the arterial wall in response to changes in transmural pressure or concentration of carbon dioxide in blood. We have investigated whether slow waves in ABP and ICP may be used to derive an index which reflects reactivity of vessels to changes in arterial blood pressure. METHODS: A method for the continuous monitoring of the association between slow spontaneous waves in ICP and AP has been adopted in a group of 98 head injured patients. ABP, ICP and transcranial Doppler blood flow velocity (FV) in the middle cerebral artery was recorded daily (20 to 120 minutes time periods). A Pressure-Reactivity Index (PRx) was calculated as a moving correlation coefficient between 40 consecutive samples of values for ICP and ABP averaged over 5 seconds. A moving correlation coefficient between spontaneous fluctuations of mean FV and CPP (Mx), which was previously reported to describe cerebral blood flow autoregulation, was also calculated. In an additional 25 patients, PRx was calculated and recorded continuously along with mean ICP, ABP and parameters describing ICP waveform. RESULTS: A positive PRx correlated with high ICP (r = 0.366; p < 0.001), low admission GCS (r = 0.29; p < 0.01), and poor outcome at 6 months after injury (r = 0.48; p < 0.00001). During the first two days following injury, PRx was positive (p < 0.05) in patients with unfavourable outcome. The correlation between PRx and Mx (r = 0.63) was highly significant (p < 0.000001). Continuous recordings demonstrated that PRx was able to indicate individual thresholds of vascular reactivity for CPP, ICP, and ventilation parameters. CONCLUSION: Computer analysis of slow waves in ABP and ICP is able to provide a continuous index of cerebrovascular reactivity to changes in arterial pressure, which is of prognostic significance.

Adolescent↗
PubMed1997

Verbally administered Barthel Index as functional assessment in brain tumour patients.

OBJECTIVE: To investigate verbally administered Barthel Index as a measure of functional status in patients with high grade gliomas. BACKGROUND: Barthel Index (BI) is a performance score of activities of daily living which has been validated in patients with neurological disability. While any assessment of quality of life in brain tumour patients should include all the aspects of CNS function we concentrated on measurement of physical performance status and evaluated the role of BI as a measure of palliative effect of treatment in patients with high grade glioma undergoing radiotherapy. METHODS: BI was verbally administered on 504 occasions in 107 patients with high grade glioma. The BI scores were correlated with Karnofsky performance score (KPS), and neurological performance score (NPS) as a measure of inter-index reliability. The BI's prognostic value was assessed using actuarial survival data. RESULTS: BI was sensitive to change and reflected the degree of functional impairment. In patients with high grade glioma BI correlated with KPS, and NPS (R2 = 0.872 and 0.658 respectively). BI score was also of prognostic value in terms of survival. The median survival of patients with functional independence was 9 months with moderate disability 5 months and with severe disability 4 months. CONCLUSION: Verbally administered Barthel Index is easy to use, reliable and sensitive to change and is of prognostic value. It is a useful tool in the management of patients with gliomas, as an objective evaluation of palliative effectiveness of treatment in patients with functional disability.

Activities of Daily Living↗
PubMed1997

Features and outcome of Pneumocystis carinii pneumonia according to risk category for HIV infection.

A retrospective study of Pneumocystis carinii pneumonia (PCP) was undertaken to examine differences between the presentation and outcome of PCP in AIDS patients from different risk categories for HIV infection. There were 176 PCP episodes recorded in 126 patients from the following risk categories: 69 intravenous drug misusers (IDMs), 36 homosexually infected men and 21 heterosexually infected patients. Most clinical features did not differ significantly between the 3 groups but hypercapnia was almost exclusively seen in IDMs and, if recorded, was associated with a poorer survival. Pneumothorax was more likely to complicate PCP in IDMs and, although present in all groups, concomitant bacterial respiratory infections were more common in IDMs. Recovery from PCP and the incidence of adverse events during treatment did not differ according to risk category. Subsequent survival time was shorter amongst IDMs, but the uptake of antiretrovirals in this group was significantly lower. We conclude that there are few differences in the presentation of PCP between IDMs and other risk categories for HIV infection and that these do not influence the outcomes of illness. The lower post-PCP survival in IDMs can be accounted for by a reduced uptake of antiretroviral drugs by this group.

AIDS-Related Opportunistic Infections↗
PubMed1995

Why disease due to Mycobacterium tuberculosis is less common than expected in HIV-positive patients in Edinburgh.

By December 1993, only five cases of tuberculosis were observed in the 1030 HIV-positive patients in Edinburgh, U.K., although, on the basis of historical tuberculin skin test data, between four and eight new cases of tuberculosis were expected per year. Of 310 HIV-positive patients, none of the 19 (6.1%) who were tuberculin skin test positive had developed tuberculosis after 87 months (average) of follow-up. It is suggested that new or re-infection is a more common cause of tuberculosis in HIV-positive patients than reactivation. Restriction fragment length polymorphism typing of Mycobacterium tuberculosis strains could confirm this hypothesis and support currently suggested additional infection control procedures.

Adult↗
PubMed1994

Radiosurgery/stereotactic external beam radiotherapy for malignant brain tumours: the Royal Marsden Hospital experience.

SRT is a high-precision technique of radiotherapy which delivers focused irradiation to small target volumes. In the context of external beam radiotherapy it can be described as stereotactically guided conformal radiotherapy. As the technique originated from neurosurgical technology, it has initially been limited to single fraction treatment. However, with the use of relocatable fixation devices the way ahead particularly in its application in the treatment of brain tumours is in fractionated SRT. Currently, single fraction SRT/radiosurgery is of proven value only in the treatment of small inoperable arteriovenous malformations. It is being exploited in the management of brain tumours but so far remains as experimental treatment. We have demonstrated that fractionated SRT in patients with gliomas is a non-invasive equivalent to brachytherapy and in patients with solitary metastases a non-invasive alternative to surgical excision. However, the treatment is not without side effects, and the long-term effectiveness and toxicity of SRT, particularly with the use of unconventional fractionation, is not defined. The future use of SRT in the treatment of brain tumours should not be guided simply by the technical possibilities but by a rational appraisal of all treatment options to achieve the best disease control, survival and toxicity. Although there is potential for benefit in a number of small tumours, SRT cannot at present be recommended as the primary treatment in any tumour. In addition, its use should be discouraged in the treatment of unbiopsied brain lesions and as the major form of treatment of pineal germinomas. The technology of stereotactic radiotherapy is evolving, and it is likely that SRT will be integrated into conventional radiotherapy practice to become simply a high-precision technique of radiotherapy delivery in everyday use.

Actuarial Analysis↗
PubMed1993

Perceived risks of postoperative analgesia.

This survey aimed to determine what type of information patients want about the risks of postoperative pain management and whether this corresponded to the information that doctors and nurses wished to provide. Seventy-four patients scheduled for elective surgery, 50 nurses and 48 doctors completed a questionnaire asking about perceived risks of analgesia, level of acceptable risk and information that should be provided to patients. Compared to doctors and nurses, patients underestimated the risks associated with postoperative pain relief, except for the risk of drug addiction, which they rated higher. Ninety-one per cent of patients wanted information about the side effects of analgesia. The preferred means of obtaining this information was by discussion with their surgeon or anaesthetist. Doctors were willing to accept a greater risk of minor side effects to achieve excellent pain relief than were patients. In contrast, patients were willing to accept a greater risk of serious side effects. The results obtained in this survey will facilitate the preparation of guidelines for obtaining informed consent from patients to receive postoperative analgesia.

Adult↗
PubMed1992

A strategy for promoting improved pharmaceutical use: the International Network for Rational Use of Drugs.

Over the last decade, pharmaceutical selection, procurement, distribution, and financing have improved as a result of essential drugs programs. However, despite improved availability, pharmaceuticals are frequently used irrationally. The International Network for the Rational Use of Drugs (INRUD) has been established to help address this problem. The Network joins core groups of researchers from four African and three Asian countries with support groups in Boston, Sweden, WHO, and Australia. The activities of the Network are supported by multilateral, bilateral, foundation donors and by Management Sciences for Health. INRUD functions as a participatory organization in which members are involved in decision-making. The primary objective of the Network is to identify through a coordinated set of country-based research projects a set of effective interventions to recommend as policy options for the promotion of rational drug use. In developing these research projects, INRUD stresses the importance of a multi-disciplinary perspective for adequately understanding the reasons underlying inappropriate use of drugs. To better enable country groups to utilize strong research methodologies and to blend the strengths of multiple disciplines effectively, a major activity of the Network thus far has been the building of local research capacity.

Africa↗
PubMed1991

Integration of AIDS program activities into national health systems.

In this paper we have defined integration as being the health unit team acceptance of responsibility for all aspects of care at the health service/community interface level. The health unit functions within a system whose elements (hospitals, laboratory, pharmacy, etc.) function in complementarity with those of the FLHS. Vertical approaches are often adopted because of weaknesses in some elements of the NHS, thereby further undermining such an NHS. The development of innovative community-based approaches in some areas and countries has resulted from this type of situation. However, isolated from the NHS, such approaches cannot be expected to be sustainable or to have long-term impact. Integration is the best choice of approach; it offers a chance to influence the course of the AIDS epidemic and the response of health systems in each country. The basic structure of the NHS and the characteristics of a FLHS are analyzed. The challenge to AIDS programs is to define more exactly objectives and activities at the operational, interface levels. Based on this analysis, planning of operations should be delegated to the district. Weakness of some elements and aspects of the NHS which are relevant to AIDS control program implementation can be overcome, not by organizing the program vertically and independently from the NHS, but rather by sharing resources to strengthen the weak elements. Integration may be more difficult in the early stages of implementation, but in the long term it offers sustainable development of AIDS prevention and control activities.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Iodine deficiency disorders in Zimbabwe. No change in prevalence of endemic goitre in Wedza District, as shown by school surveys carried out 18 years apart.

Goitre prevalence surveys were carried out in 1986 in five primary schools in Wedza District and the results compared with those obtained from the same schools in 1968. Overall, goitre prevalence was 73 percent and there had been no significant change since 1968. In 1986 the visible goitre rate was 14 percent. Goitre was more common in girls on both occasions. Evidence (though not conclusive) of milder forms of endemic cretinism was found. The need for a nationwide iodination programme is emphasised.

Adolescent↗
PubMed1989

Conservative surgery for early breast cancer results from a district hospital.

Wide local excision followed by radiotherapy was offered as an alternative to mastectomy to 93 women on 96 occasions. Complications attributable to the surgery occurred in 4 per cent whilst 37.5 per cent developed complications secondary to the radiotherapy. The complications were generally of a mild nature. Nine patients (9.3%) have developed regional recurrence and seventeen (17.7%) distant metastases with a mean follow up of 53.4 months.

Adult↗