Antiretroviral therapy in a thousand patients with AIDS in Haiti

BACKGROUND

The one-year survival rate of adults and children with the acquired immunodeficiency syndrome (AIDS), without antiretroviral therapy, has been about 30 percent in Haiti. Antiretroviral therapy has recently become available in Haiti and in other developing countries. Data on the efficacy of antiretroviral therapy in developing countries are limited. High rates of coinfection with tropical diseases and tuberculosis, along with malnutrition and limited laboratory monitoring of therapy, may decrease the efficacy of antiretroviral therapy in these countries.

METHODS

We studied the efficacy of antiretroviral therapy in the first 1004 consecutive patients with AIDS and without previous antiretroviral therapy who were treated beginning in March 2003 in Port-au-Prince, Haiti.

RESULTS

During a 14-month period, three-drug antiretroviral therapy was initiated in 1004 patients, including 94 children under 13 years of age. At enrollment, the median CD4 T-cell count in adults and adolescents was 131 per cubic millimeter (interquartile range, 55 to 211 per cubic millimeter); in children, a median of 13 percent of T cells were CD4-positive (interquartile range, 8 to 20 percent). According to a Kaplan-Meier survival analysis, 87 percent of adults and adolescents and 98 percent of children were alive one year after beginning treatment. In a subgroup of 100 adult and adolescent patients who were followed for 48 to 56 weeks, 76 patients had fewer than 400 copies of human immunodeficiency virus RNA per milliliter. In adults and adolescents, the median increase in the CD4 T-cell count from baseline to 12 months was 163 per cubic millimeter (interquartile range, 77 to 251 per cubic millimeter). In children, the median percentage of CD4 T cells rose from 13 percent at baseline to 26 percent (interquartile range, 22 to 36 percent) at 12 months. Treatment-limiting toxic effects occurred in 102 of the 910 adults and adolescents (11 percent) and 5 of the 94 children (5 percent).

CONCLUSIONS

This report documents the feasibility of effective antiretroviral therapy in a large number of patients in an impoverished country. Overall, the outcomes are similar to those in the United States. These results provide evidence in support of international efforts to make antiretroviral therapy available to patients with AIDS in developing countries.

Bone mineral decrease in the leg with unilateral chronic occlusive arterial disease

OBJECTIVE

The links between osteoporosis and arteriosclerosis have been established by numerous epidemiological studies. Could arteriosclerosis induce bone mineral loss via ischemia or other pathological process? We carried out a comparative study of bone mineral density in both legs of patients with unilateral arterial disease of the lower limbs.

METHODS

We studied 25 patients, 22 men and 3 women, whose mean age was 62.3 years (range 35-88 years). These patients had unilateral lower limb arterial disease of at least 3 months duration with a systolic index at least 50% lower on the affected than on the healthy side. Bone mineral content (BMC) and bone mineral densities (BMD) of the femoral neck, femur, tibia, foot and ankle of the affected and the unaffected legs were measured by dual x-ray absorptiometry (Lunar DPXL) and the results compared.

RESULTS

Bone mineral density was significantly lower in the femur (-3.7%, p = 0.04), the foot and the ankle (-3%, p = 0.05) of the affected leg. There was a non-significant decrease in BMD of the whole femoral neck (-1.2%) and the trochanter (-4.4%, p = 0.08) on the affected side. Tibial bone mineral density was identical in both legs. Bone mineral content was lower on the affected side (-5.3%, p = 0.05) whereas fat mass and muscle mass were the same in both legs.

CONCLUSION

The ischemia resulting from arterial disease of the lower limbs appears to have a direct deleterious effect on bone mineralization.

Infrastructure, funding and follow-up in a programme of noninvasive ventilation

Originating from centres charged with the care of patients with chronic respiratory insufficiency, noninvasive ventilation (NIV) has been used increasingly in chronic and acute respiratory failure during the last decade. Despite a considerable number of series and randomised studies advocating access to NIV for units that treat acute or chronic ventilatory failure, the number of units and the proportion of total ventilatory support remains poor. This is due to lack of education, as many units treat only a few patients per year. Indication, technique, education, monitoring and home care require special experience and a special environment and there is a wide range throughout Europe. With respect to home care in particular, there are many organisations, which range from totally private to hospital based or run for profit. A concerted action, funded by the European Union, will soon provide valuable information about the practice of home ventilation in Europe based on a European survey.

La Pitié heart transplantation: 30-year single center clinical experience

At La Pitié Hospital, 1,184 patients underwent cardiac transplantation for end-stage cardiac disease (1,122 orthotopic and 62 heterotopic) between April 1968-November 1998. Since April 1986, 140 patients have been supported using several different mechanical assist devices as a bridge to transplantation. Twenty-four retransplantations (2.2%) were performed for primary graft failure in 4 (17%), refractory acute rejection in 7(29%), coronary graft disease in 11 (46%) and others in 2 (8%) patients. In a case-control study, retransplanted patients were matched with first transplant patients and survival rates at one and 5 years were 59.4% and 38.8% compared with survival rates for retransplanted patients of 45.4% and 31.2%, respectively. Seventy-four patients survived more than 10 years (61 males, 13 females). Mortality did not increase after 10 years. Unfortunately many suffered complications: 77% had hypertension, hypercholesterolemia (22%), hyperuricemia (41%), osteoporosis (11%), osteonecrosis (5%) and diabetes (7%). Renal function remains one of the main problems; 16% had a creatinine > 180 mumol/L and patients are on chronic dialysis.

Time-variant spectral analysis of LDF signals on the basis of multivariate autoregressive modelling

Time-variant AR-modelling was used to analyse the non-stationary properties of LDF signals during provocation tests. The procedure for the estimation of time-varying AR parameters based on Kalman filtering is presented. The estimates can be used to calculate instantaneous measures, such as peak frequency, spectral band power and coherence. The resulting course of instantaneous peak frequency of a sinusoidal signal with frequency jump was compared to similar parameters derived from short-time FFT and Hilbert transformation. Univariate time-variant spectral analysis was used to investigate LDF measurements in patients with Raynaud's phenomena. The experimental protocol was splitted into phases of different room temperature. The results demonstrate time-dependent variations of spectral components (amplitude and frequency). By means of time-variant coherence analysis of LDF and diameter measurements of vessels in a hamster skin fold the existence of a main rhythm around 0.1 Hz in the LDF signals which is related to vasomotion is shown.

Spectral analysis of laser-Doppler perfusion signal measured during thermal test

The method of spectral analysis of laser-Doppler perfusion signal measured during thermal test is proposed. During three 20 min phases with 40, 5, and 40 degrees C of thermal test laser-Doppler perfusion signal was recorded. For each signal phase frequency spectra were calculated using the FFT method. Quantitative parameter Spectral Factor for results evaluation was proposed. In total 94 patients were measured: 69 with Raynaud's phenomenon and 25 normal subjects. Additionally in 18 Raynaud's patients the influence of Nifedipine was studied. Results suggest that proposed parameter is able to differentiate between Raynaud's patients and normal subjects and that is useful for evaluation of Nifedipine effectiveness. However, further studies are needed to improve the method to differentiate between primary and secondary Raynaud's patients.

Dynamic characteristics of laser-Doppler flux in normal individuals and patients with Raynaud's phenomenon before and after treatment with nifedipine under different thermal conditions

The study was aimed at choosing an appropriate characteristic of laser-Doppler flux (LDF) data for (1) distinguishing patients with Raynaud's disease from normal controls and (2) evaluating the effect of nifedipine under different thermal conditions. We checked the reliability of three characteristics of nonlinear dynamics as statistical dimension Ds, correlation dimension D2 and power-law index PLI. Their values depended heavily on the thermal condition. The most reliable characteristics that enabled us to distinguish the patients from normal controls and the effect of nifedipine under definite thermal condition proved to be Ds and PLI. The latter is simple for computation and is thus recommendable for clinical practice. Ds and PLI were higher in patients with Raynaud's compared to normal controls and diminished during the transitions from low to high temperature. However, the characteristics used were unable to distinguish significantly Raynaud's I from Raynaud's II patients.

Linear and nonlinear analysis of blood flow in healthy subjects and in subjects with Raynaud's phenomenon

The paper presents analyses of the dynamics contained in the blood flow signals measured on healthy subjects and on subjects with primary Raynaud's phenomenon. Different signal processing methods are presented and discussed. The dynamics was evaluated in the time and frequency domains and in phase space. Additionally, changes in the basal value during temperature provocation were studied using multiresolution analysis. The analyses demonstrate differences between the blood flow dynamics in healthy subjects and subjects with Raynaud's phenomenon. Moreover, the observed decrease in the amplitude of oscillation in regions approximately 0.04 Hz and approximately 0.1 Hz suggests an impairment in the neurogenic and the myogenic regulation of the blood flow. The administration of nifedipine in subjects with Raynaud's phenomenon results in an increase in the basal value and in the amplitude of the blood flow component oscillating with the heart rate. However, it does not restore the dynamics to that found in healthy subjects.

Different flowmotion patterns in healthy controls and patients with Raynaud's phenomenon

Flowmotion was characterized in healthy controls and 61 Raynaud's phenomenon (RP) patients by spectral analysis of laser-Doppler perfusion monitoring (LDPM) tracings. Healthy subjects flowmotion patterns revealed a main frequency of 3 cycles per min (cpm) with another low frequency and heart rate synchronous components. A first group of RP patients presented a low frequency and heart rate frequency component but no significant difference in blood flow. The second group presented the predominating heart rate related frequency with low microvascular perfusion. The third group presented a flowmotion pattern with overlapping of heart rate and low frequency components. Patients with primary and secondary RP show specific changes in flowmotion, probably related to increased sympathetic nervous activity or vessel wall alterations causing disappearance of arteriolar tone and impairment of microvascular perfusion. The group of patients with overlapping frequency components presents an intermediate flowmotion pattern indicating a different grade of alterations in microvasculature.

Higher-order spectral analysis in laser-Doppler flowmetry signal processing

This paper presents an application of higher order statistics and spectra to the problem of laser-Doppler Flowmetry (LDF) for microcirculation monitoring. The proposed signal processing technique computes the bispectra of LDF signals after appropriate pre-processing and extracts features which can be used for classification of the signals to a normal or patient category. Bispectra are defined in terms of the third-order moments or cumulants of signals and are shown to contain valuable information for the above classification of LDF signals. Experimental studies, including (a) a set of 17 normal subjects and 69 patients with Raynaud's phenomenon and (b) 50 LDF-signals separated to four groups from patients that have different pathologic characteristics, are described and results are presented which illustrate the performance of the proposed approach when applied to the LDF signals.

Preventing, minimizing, and managing postoperative bleeding

BACKGROUND

Most bleeding in cardiovascular surgery is biological, not surgical, the result of disseminated intravascular coagulation in its latter phases. Disseminated intravascular coagulation bleeding affects all levels of the coagulation systems, requiring stabilization of the platelet system, balancing the procoagulant system and its regulation, and stopping the fibrinolytic system's activation.

METHODS

The article discusses the multisystem protocol put into place at the Cardiovascular Surgery Department of La Pitié Hospital in Paris to diagnose and treat DIC bleeding so as to slow down causes of its occurrence and prevent further deterioration of the hemostatic systems.

RESULTS

All biological bleeding was controlled, permitting detection of other causes of bleeding and allowing rational use of blood products. No thromboembolic accident occurred. There was an absence of iatrogenic bleeding. The protocol also detects disseminated intravascular coagulation in patients who did not bleed to take early and frequently lifesaving measures.

CONCLUSIONS

This demonstrates the need to treat bleeding through a multisystem approach, monitoring its evolution by means of biological tests to be able to provide appropriate treatment.

Comparative of blood flow to the ankle-brachial index after iliac angioplasty

BACKGROUND

Interest of blood flow and ankle brachial pressure index (ABPI) to evaluate result of iliac angioplasty.

METHODS

ABPI and blood flow rates were measured before and after angioplasty in 22 lower extremities of 16 patients with iliac stenosis. Blood flow rates were determined by means of a nuclear magnetic resonance (NMR) flow meter.

RESULTS

The day after angioplasty, flow and pressure were increasing significantly, whereas a month later, only blood flow was increasing significantly. In a group of patients with near-normal ABPI before angioplasty (ABPI > or = 0.8), there was, on the day following the angioplasty, a significant increase in ABPI and pulsatile blood flow rates; flow rates increased considerably a month after the operation whereas ABPI stay stable. In a group of patients with clearly abnormal ABPI before angioplasty (ABPI <0.80), there was a significant increase in ABPI and blood flow rates the day after angioplasty and again a month later.

CONCLUSIONS

Flow therefore seems to vary independently of pressure. The possible use of flow measurement to detect restenoses is yet to be studied.