The use and cost of HIV service provision in England in 1996. National Prospective Monitoring System (NPMS) Steering Group and NPMS Working Party on Costs.

OBJECTIVE: The aim of the study was to measure the use and estimate the cost of HIV service provision in England. DESIGN AND SETTING: Standardised activity and case-severity data were collected prospectively in 10 English HIV clinics (5 London and 5 non-London sites) for the periods 1 January 1996 to 30 June 1996 and 1 July 1996 to 31 December 1996 and linked to unit cost data. In total, 5440 patients with HIV infection attended during the first 6 months and 5708 during the second 6 months in 1996. MAIN OUTCOME MEASURES AND RESULTS: The mean number of inpatient days per patient-year for patients with AIDS was 19.7 [95% confidence interval (CI): 13.7 to 25.7] for January to June and 20.8 (95% CI: 15.3 to 26.4) for July to December 1996. The mean number of outpatient visits for asymptomatic patients with HIV infection was 14.8 (95% CI: 11.9 to 17.6) and 13.3 (95% CI: 10.8 to 15.7) for the respective periods and 16.1 (95% CI: 13.21 to 18.97) and 15.7 (95% CI: 11.2 to 20.2), respectively, for patients with symptomatic non-AIDS (i.e. symptomatic patients with HIV infection but without AIDS-defining conditions). Substantial centre-to-centre variation was observed, suggesting that many clinics can continue the shift from an inpatient- to an outpatient-based service. Cost estimates per patient-year for HIV service provision for 1996 varied from 4695 Pounds (95% CI: 3769 Pounds to 5648 Pounds) for asymptomatic patients, to 7605 Pounds (95% CI: 6273 Pounds to 8909 Pounds) for symptomatic non-AIDS patients to 20,358 Pounds (95% CI: 17,681 Pounds to 23,206 Pounds) for patients with AIDS. CONCLUSIONS: Different combinations of antiretroviral therapy affect the cost estimates of HIV service provision differently. Anticipated reduction in inpatient-related activity through the increased use of combination antiretroviral therapy will further shift service provision from an inpatient- to outpatient-based service and reduce costs per patient-year. The extent and duration of such effects are currently unknown. The long term effects of combination treatment on the morbidity and mortality patterns of individuals infected with HIV are also currently unknown, as are their implications on the use and cost of HIV service provision. Multicentre databases like the National Prospective Monitoring System (NPMS) will provide healthcare professionals with information to improve existing services and anticipate the impact of new developments.     

Asbestos-related focal lung masses: manifestations on conventional and high-resolution CT scans

In 260 asbestos-exposed individuals evaluated by means of computed tomography (CT), 43 unsuspected pulmonary masses were found in 27 individuals. The masses included fissural pleural plaques (n = 10), dense fibrotic bands (n = 3), round atelectasis (n = 11), carcinomas (n = 3), and other presumed benign masses (n = 16). The most helpful features in the diagnosis of rounded atelectasis with CT were (a) contiguity to areas of diffuse pleural thickening, (b) a lentiform or wedge-shaped outline, (c) evidence of volume loss in the adjacent lung, and (d) a characteristic "comet tail" of vessels and bronchi sweeping into the margins of the mass. Less advanced areas of focal atelectasis had fewer classic features. Intrafissural pleural plaques were readily identified with high-resolution CT. In asbestos-related masses, the demonstration of stability over time is necessary. Careful interpretation of CT and high-resolution CT features and close surveillance can obviate the need for biopsy in the majority of instances.     

Photons, physiatrics, and physicians: a practical guide to understanding laser light interaction with living tissue, part I

In the past 32 years, lasers have progressed from interesting curiosities to important instruments in medicine and surgery, with a wide variety of wavelengths and medical-surgical applications. Today's physician is faced with a bewildering array of laser types, each touted by its manufacturer as the ultimate surgical tool. This article sets forth in simple, understandable prose, the basic principles of the interaction of laser light with living tissue, so that the physician can decide which type of laser is best suited to a given application, without relying on the manufacturer's sales literature. The topics discussed are the nature of light; reflection, absorption, scattering, and attenuation in living tissue; physical processes by which laser light destroys tissue; relative importance of the three unique properties of laser light in surgery and therapy; temporal modes of lasers; means of delivering laser beams to their targets; and considerations in the selection of laser systems.     

Hypnotizability and recovery from cardiac surgery.

We studied 32 coronary bypass patients to examine the effect of hypnosis on recovery from surgery. The patients were assessed for hypnotizability with the Hypnotic Induction Profile (HIP) and assigned to experimental groups with a random stratification procedure to equate for differences in hypnotizability, age, and severity of illness. We taught patients in groups one and two formal hypnosis with different treatment strategies; patients in group three were not taught formal hypnosis or a treatment strategy. Scores on the HIP were significant predictors of recovery, independent of experimental treatment with formal hypnosis. Patients who scored "Midrange" stabilized more quickly in the intensive care unit (ICU) than those who scored "High" or "Low" (p = < .05). Patients who scored "High" had more labile blood pressure in the ICU compared to the "Midrange" and "Lows" (p = < .05). Measured hypnotizability was associated with the recovery sequence from surgery.     

Dominant lethal assay of 2,4-pentanedione vapor in Fischer 344 rats

2,4-Pentanedione (2,4-PD: CAS No. 123-54-6) is a volatile industrial chemical of moderate acute toxicity, centrally neurotoxic by repeated exposure to high vapor concentrations, fetotoxic, and clastogenic. Its wide use and known toxicology indicated the conduct of a dominant lethal assay. Male Fischer 344 rats, 20 per group, were exposed to 2,4-PD vapor concentrations (mean +/- SD) of 0, 99.1 +/- 2.2, 412 +/- 12.6 and 694 +/- 9.1 ppm, for 6 hr/day for 5 consecutive days. The day following the final exposure they were bred to unexposed female Fischer 344 rats, 2 per week for 8 consecutive weeks. Weight loss occurred with males during 2,4-PD exposure for the 412 and 694 ppm groups, with compensatory increased weight at 694 ppm, for the first two weeks postexposure. No histopathological change was seen in brain, testes or thymus from high concentration males sacrificed after eight weeks of mating. Minor transient reproductive and gestational effects were present at 412 and 694 ppm. At week 2 there was a reduction, not statistically significant, in the number of corpora lutea and total and viable implants per dam at 694 ppm, and a slight increase in preimplantation loss. At week 3 the number of pregnant females was slightly reduced at 412 and 694 ppm, causing a lowered female fertility index. At week 4 there was a slight reduction in the number of total and viable implants per litter and a significant preimplantation loss at 694 ppm. The dominant lethal factor (FL%) was increased slightly at 694 ppm for weeks 2 and 4. Thus, the "no observable effect" level for dominant lethal effects was 99 ppm. The results, although not statistically significant, are dose-related and compatible with a transient slight dominant lethal effect at the spermatid stage of spermatogenesis.     

Asthma and the diver

Self-contained underwater breathing apparatus (scuba) diving has grown in popularity, with nearly 9 million sport divers in the United States alone. Approximately 7% of the population has been diagnosed with asthma, which is similar to the percentage of divers admitting they have asthma. Numerous concerns exist regarding subjects with asthma who choose to participate in recreational diving. Among these concerns are pulmonary barotrauma, pneumomediastinum, pneumothorax, arterial gas embolism, ear barotrauma, sinus barotrauma, and dental barotrauma. Despite these concerns, a paucity of information exists linking asthma to increased risk of diving complications. However, it has long been the norm to discourage individuals with asthma from participating in recreational scuba diving. This article examines the currently available literature to allow for a more informed decision regarding the possible risks associated with diving and asthma. It examines the underlying physiological principles associated with diving, including Henry’s law and Boyle’s law, to provide a more intimate understanding on physiological changes occurring in the respiratory system under compressive stress. Finally, this article offers a framework for guiding the patient with asthma who is interested in scuba diving. Under the right circumstances, the patient with asthma can safely participate in recreational diving without apparent increased risk of an asthma-related event.