Why do community health workers volunteer? A qualitative study in Kenya.

OBJECTIVES: Globally, there is a dire shortage of healthcare workers, but the situation is particularly bad in low- and middle-income countries. To address this, task shifting of clinical work to lower-level staff, including volunteer health workers, has been used. Whilst there are examples worldwide of such an approach working, the sustainability of programmes based on a volunteer workforce is less certain. In addition, little is known about the factors that motivate such volunteers. This study sought to ascertain these motivational drivers. STUDY DESIGN: Qualitative study using focus group discussions. METHODS: Qualitative study of volunteer community health workers (CHWs) in a rural district of Western Kenya. Twenty-three CHWs were sampled purposively, and took part in six focus group discussions. Thematic analysis was performed on the transcribed discussions. RESULTS: A variety of factors were identified as important drivers of motivation. These included financial as well as non-financial drivers, such as personal recognition, personal development and working conditions. CONCLUSIONS: There are serious unanswered questions regarding the viability of healthcare programmes founded on a workforce reliant on volunteer CHWs. This study revealed the importance of some form of reward, be it financial or otherwise, in order to retain and maintain the engagement and motivation of volunteer CHWs in these settings.

Displacement of gold marker in immunoelectron microscopy of human respiratory cilia.

Preembedding immunogold electron microscopy was performed to evaluate the position of outer arm dynein heavy chains in normal human respiratory cilia. Anti-dynein antibody (AD2), which is specific for sea urchin sperm flagellar dynein heavy chains, was used as primary antibody. Direct cross-sections of cilia were selected, and the distance between the center of a cilium and the center of a colloidal gold particle attached to the cilium (X) was measured. The distance between the center of a cilium and the farthest edge of an outer dynein arm of the cilium was measured by ordinary electron microscopy (Yo) and by immunoelectron microscopy (Yi). X was significantly longer than Yo and Yi. If it is assumed that the structure of respiratory cilia is dense and that antibodies are located at the outer side of the actual position of the heavy chains, then the average distance difference of approximately 90-120 A may represent the length of two conjugated antibodies. This length should be kept in mind when performing immunoelectron microscopy. The data suggest that AD2 recognizes the outer arm dynein heavy chains of normal human respiratory cilia.

Effects of pH and SO2 on solubility coefficients of inert gases in human whole blood.

We systematically investigated the quantitative importance of pH and O2 saturation (SO2) of hemoglobin on the solubility coefficients (alpha) for six inert gases: sulfur hexafluoride, N2, ethane, cyclopropane, halothane, and diethyl ether. Measurements of alpha were made at 37 degrees C with SO2 of 0-1.0 and pH of 7.2-7.7 by use of whole blood obtained from three healthy subjects. No significant dependence of alpha on pH was demonstrated for sulfur hexafluoride, N2, halothane, or diethyl ether, but an appreciable augmentation of alpha with increasing pH was found for ethane and cyclopropane. No alpha value obtained for oxygenated blood differed statistically from that for deoxygenated blood. In addition to the basic findings on the effects of pH on alpha values of ethane and cyclopropane with the multiple inert gas elimination technique (data obtained from 22 patients with either interstitial pneumonia or chronic obstructive pulmonary disease), we also found that dependence of alpha on blood pH exerted no significant influence on the recovery of ventilation-perfusion distribution in the lung. We concluded that: 1) pH plays an appreciable role in determining gas solubilities in blood, 2) SO2 is not a decisive factor for gas solubilities in blood, and 3) the influence of various pH values in pulmonary capillaries on inert gas exchange is negligible.

Effects of SO2 and pH on blood-gas partition coefficients of inert gases.

Potential effects of SO2 and of pH on blood-gas partition coefficients, lambda, for inert gases, including SF6, ethane, cyclopropane, halothane, diethyl ether, acetone and N2, were systematically investigated using human blood. Measurements on lambda were performed at 37 degrees C in conditions of varied SO2 and pH using gas chromatography. Incorporating the experimental data on lambda, multiple inert gas elimination was applied to 18 patients with varied chronic lung diseases, in order to estimate the effects of SO2 and of pH on both inert gas exchange and resultant recovery of VA/Q distribution in the lung. For this purpose, the data obtained by the procedure of multiple inert gas elimination were analyzed with the classical approach but allowance was made for lambda of the indicator gas to vary according to exchange of O2 and of CO2 in the pulmonary capillary. Among the gases studied, ethane, cyclopropane, halothane and diethyl ether showed significantly smaller lambda values in the oxygenated blood than in deoxygenated blood, whereas SF6, acetone and N2 were little dependent on SO2. An increase in lambda was found for ethane and a decrease for halothane with increasing pH in the blood. The other gases were not significantly influenced by pH. In spite of these experimental findings, regional difference of either SO2 or pH in the lung did not exert important influence on the inert gas exchange or on the predicted VA/Q distribution. In conclusion, blood-gas partition coefficients of some inert gases are consistently altered by SO2 and pH, but their possible effects on inert gas exchange seem to be negligible.

Continuous distributions of ventilation and gas conductance to perfusion in the lungs.

Theoretical analysis and experimental observations were conducted to establish a method allowing to demonstrate the characteristics of distribution of ventilation (VA) as well as of diffusive conductance (G) to perfusion (Q) in the lungs. O2, CO2 and CO binding to hemoglobin molecules within the erythrocyte together with six inert gases including SF6, ethane, cyclopropane, halothane, diethyl ether and acetone, of varied solubility in blood and different diffusivity in lung tissue, were used as indicator gases. 15 patients with interstitial pneumonia of unknown etiology, placed in the supine position, were given a mixture of 21% O2 and 0.1% CO in N2 as the inspired gas and saline containing appropriate amount of the six inert gases was infused via an antecubital vein. After a steady state was established, the expired gas was collected and the samples of both arterial and mixed venous blood were simultaneously taken through catheters inserted into the femoral and pulmonary artery. The concentrations of the indicator gases in the samples were measured by gas chromatography, with electrodes or with the Scholander gas analyzer. Assuming that the mass transfer efficiency of a given indicator gas at each gas exchange unit would be limited by VA/Q and G/Q ratios, the data obtained from the human subjects were analyzed in terms of a lung model having 20 units along the VA/Q and G/Q axes, respectively. The numerical analysis including the procedure of simultaneous Bohr integration for O2, CO2 and CO in a pulmonary capillary and the method of weighted least-squares combined with constrained optimization permitted the data to be transformed into a virtually continuous distribution of Q against VA/Q and G/Q axes. The numerical procedure was strictly tested using various artificial distributions of VA/Q and G/Q ratios, showing that it could characterize the distributions containing up to at least two modes on VA/Q-G/Q field with a substantial accuracy. Analytical results estimated from the patients with interstitial lung disease revealed the following features. (1) There appears to be bimodal distribution of Q along G/Q axis extending to relatively low G/Q less than 10(-3) ml(STPD)/(ml.Torr), which may limit O2 exchange between alveolar gas and capillary blood. This area of low G/Q receives 10% of total Q. (2) Severe diffusion limitation causing disequilibrium of the inert gas across the blood-gas barrier is solely observed in 2 out of 15 patients and an amount of Q associated with this phenomenon is very small (below 1%).(ABSTRACT TRUNCATED AT 400 WORDS)

Attenuation of hypoxic pulmonary vasoconstriction in acute oleic acid lung injury--significance of vasodilator prostanoids.

To assess a significant role of hypoxic pulmonary vasoconstriction, HPV, on maintaining the gas exchange efficiency in acute lung injury, 24 mongrel dogs were treated with intravenously injecting 0.07 ml/kg of oleic acid. Hemodynamic and gas-exchange parameters were investigated at varied inspired O2 concentration, FIO2. To know a possible contribution of vasoactive prostanoids in regulating vascular reactivity under these circumstances, observations were repeated after infusion of indomethacin. The impairment of gas exchange in injured lungs was examined by measuring the fractional retention, R, of the gas in arterial blood. For this evaluation, a normal saline containing five foreign inert gases such as sulfur hexafluoride, SF6, ethane, cyclopropane, halothane and diethyl ether was infused at a constant rate through a peripheral vein. After a steady state was established, the expired gas was collected and the samples of both arterial and mixed venous blood were simultaneously taken for the inert-gas analysis. The concentrations of the indicator gases in the samples were measured in terms of a gas chromatograph equipped with an electron capture detector for SF6 and a flame ionization detector for the other four gases. Although pulmonary vascular resistance, PVR, after injecting oleic acid at FIO2 0.60 was significantly smaller than that obtained at FIO2 0.21, cardiac output, QT as well as extravascular lung water were not different between the two conditions. R value for the indicator gas was consistently lower at FIO2 0.60 irrespective of the gas species. As increasing FIO2, R estimate concerning SF6, RSF6, rational index of the fractional blood flow perfusing shunt area, decreased significantly. Administration of indomethacin caused the rise in PVR without an appreciable change in either QT or extravascular lung water but a considerable diminution in R value for the inert gas. RSF6 after infusion of indomethacin decreased from 0.35 to 0.27, accompanied by a significant rise in arterial PO2 from 84 to 99 Torr. The findings are highly compatible with the idea that HPV is distinctly attenuated in diseases areas induced by oleic acid probably due to a local accumulation of vasodilator prostanoids. Inhibiting prostanoid biosynthesis may selectively enhance the vascular reactivity to O2 in shunt vessels and may redistribute the perfusion from shunt to relatively normal areas, thereby improving gas exchange at alveolar region without altering the total amount of extravascular lung water.

Behavior of stimulated leukocytes in the pulmonary microcirculation of perfused rat lungs.

To investigate the dynamics of activated leukocytes and the roles of CD18-ICAM-1 pathway, we examined the effects of rat IL-8 and monoclonal antibodies (mAbs) against CD18 and ICAM-1 on the behavior of leukocytes in microvessels of perfused rat lungs. Specific pathogen free male Sprague-Dawley rats were used. Perfused rat lungs were prepared so as to obtain stable physiological shear rates. We used a confocal laser scanning microscope equipped with a high speed video analysis system to visualize pulmonary microcirculation. Rat leukocytes were activated with rat IL-8. No rolling leukocytes were observed in either pulmonary arterioles or venules, and leukocytes were sequestered in capillaries. The majority of unstimulated capillary leukocytes moved smoothly. About 50% of stimulated leukocytes, however, showed a transient cessation of movement in pulmonary capillaries. Rat IL-8 decreased the relative leukocyte velocities against mean blood velocities in capillaries (45%) and venules (65%), and increased intracapillary neutrophils. Anti-CD18 and anti-ICAM-1 mAbs attenuated these changes. These results suggest that unique features exist in the interaction between activated leukocytes and pulmonary microvessels, and that CD18-ICAM-1-dependent capillary sequestration is one of the major mechanisms by which activated leukocytes accumulate in lungs.

Clinical presentation of pulmonary tuberculosis associated with acquired immunodeficiency syndrome in metropolitan Tokyo.

The clinical features of pulmonary tuberculosis associated with acquired immunodeficiency syndrome (AIDS) in Japan were surveyed utilizing questionnaires completed by 48 institutes around the Tokyo metropolitan area. We found 11 Japanese and six foreign patients. The average number of patients per institute was 0.37. The Japanese patients had advanced human immunodeficiency virus (HIV) infection. A middle aged man, with fever and cough, nonspecific chest X-ray infiltrates, decreased lymphocyte counts, and a negative tuberculin skin test was the typical presentation of the Japanese patients. The clinical diagnosis was often difficult. The smear positive rate was high among those from whom smears were obtained, suggesting high communicability. None of the isolates indicated multidrug-resistant tuberculosis at the time of diagnosis. In conclusion, sputum smear and culture remain the keys to diagnosing tuberculosis in patients with AIDS, although the clinical picture may be atypical for pulmonary tuberculosis.

Fatal hepatic failure caused by miliary tuberculosis in a hemodialysis patient: case report.

A 57 year-old male dialysis patient died soon after the onset of high fever, hypoglycemia, and disturbance of consciousness. Autopsy revealed granulomatous lesions associated with caseous necrosis mainly found in the liver, despite the absence of pulmonary changes on chest radiographs performed during the patients illness. It appears that tubercle bacilli were hematogenously disseminated mainly to the liver causing miliary tuberculosis without producing typical diffuse lesions in the lungs. Since tuberculosis is a common complication in hemodialysis patients, the potential development of atypical miliary tuberculosis should always be borne in mind.

[A case of infective endocarditis due to Streptococcus agalactiae].

A 60 year-old woman, who was pointed out as having hyperglycemia, was admitted to our hospital, with a two-week history of fever. Blood sugar on admission was 424 mg/dl and blood cultures yielded Streptococcus agalactiae. Systolic and diastolic heart murmurs were heard. Echocardiography showed aortic regurgitation and vegetation on the aortic valve. Penicillin-G (4 million units every 4 hr) iv and streptomycin (1 g every 12 hr) im were started. Chemotherapy was continued for 48 days. After chemotherapy, aortic valve replacement was done. We reported a very rare infective endocarditis case due to Streptococcus agalactiae.

[Respiratory failure: respiratory disorder during sleep in patients with myotonic dystrophy].

Myotonic dystrophy (MyD) patients have been reported to show severe nocturnal desaturation related to sleep respiratory disorders. However, the reason of respiratory failure in MyD has remained unclear. In this study, ten patients with MyD underwent overnight polysomnography to evaluate the mechanisms which would cause respiratory failure, compared with Duchenne muscular dystrophy (DMD) patients in these three views: 1) sleep-related nocturnal desaturation, 2) histopathological evaluation of respiratory muscles, and 3) abnormalities of respiratory center. Nocturnal desaturation was more prominent in MyD rather than DMD. Apnea-hypopnea index (AHI) was higher in MyD than DMD. Type of respiratory disorder during sleep was mainly central apnea-hypopnea pattern, including Cheyne-Stokes respiration. In histopathological findings, central core change in respiratory muscle related to respiratory muscle fatigue was found less frequently in MyD than DMD. In respiratory center function, MyD showed hyporesponse to both alveolar hypercapnic and hypoxic stimulation. However, DMD showed normal response to both stimulations. We concluded that respiratory failure in patients with MyD would be attributed to respiratory center disorder rather than respiratory muscle weakness, which is the main cause of respiratory failure in patients with DMD.

[A case of AIDS with bronchial tuberculosis].

A case is 48 years-old Japanese man who had a history of frequent sexual contact with prostitutes in Thailand and the Philippines. He presented with chief complaint of chest discomfort in April 1995. His chest X-ray film showed right mediastinal lymph node swelling in other hospital and the sputum smear was strongly positive for acid fast bacilli. In May 1995, he was admitted to our hospital and serological tests for HIV were positive both by EIA and Western blot methods. The CD4 lymphocyte count was 167/microliters. He was diagnosed as a case of AIDS according to the criteria proposed by the AIDS surveillance committee of the Japanese Ministry of Health and Welfare. Although numerous tubercule bacilli were detected in sputum, the chest X-ray did not show abnormal shadow in lung fields. So the diagnosis of bronchial tuberculosis was suspected by these apparently contradictory findings and the bronchoscopy was performed. Biopsy specimen of the bronchial mucous membrane obtained by bronchoscopy confirmed the presence of acid fast bacilli by Ziehl-Neelsen's staining method, however, histological findings were atypical of tuberculosis. A month after the initiation of treatment with isoniazid, rifampicin and ethambutol and AZT, his clinical symptoms improved and the sputum smear and the culture tests for tubercule bacilli converted to negative. Complications of AIDS, (Pneumocystis carinii infection, Cytomegalo virus infection, Kaposi's sarcoma, etc) other than tuberculosis have not developed to date. In the past reports, we could not find reports of bronchial tuberculosis with AIDS. Tuberculous granuloma formation was scarce in this case, and it was suspected that bronchial tuberculosis with AIDS would show characteristic sign as same as pulmonary tuberculosis with AIDS.

[Characteristics of impaired gas exchange in patients with chronic obstructive pulmonary disease].

Eleven patients with chronic obstructive pulmonary disease (COPD), placed in a supine position, were given a mixture of 0.1% CO and 21% O2 in N2 as inspired gas and normal saline containing the six inert gases including SF6, ethane, cyclopropane, halothane, diethyl ether and acetone via the antecubital vein. After the steady state was established, the expired gas was collected and both arterial and mixed venous blood were simultaneously sampled through the catheter inserted either into the femoral or pulmonary artery. Assuming that mass transfer efficiency of a given indicator gas at each gas exchange unit would be limited by the ratio of ventilation to perfusion (VA/Q) and by that of diffusive conductance to perfusion (G/Q), the data were analyzed by means of a lung model with 20 units along the VA/Q and G/Q axes, respectively. By application of the method of weighted least-squares combined with the idea of constrained optimization, the data were transformed into a virtually continuous distribution of Q against VA/Q and G/Q axes. Analytical results revealed that: 1) patients with advanced COPD show widening of VA/Q distribution accompanied with a significant contribution of either high VA/Q (emphysematous change) or low VA/Q area (peripheral airway involvement). and 2) their Q distributions along the G/Q axis are unimodal but have an area with a relatively low G/Q, indicating a small but appreciable contribution of diffusion limitation to their hypoxemia. In conclusion, the findings consistently suggest that inhomogeneity of G/Q may partly be responsible for the impaired gas exchange in the cases of COPD.

[Proposal for a new method for evaluation of physical exercise capacity in patients with chronic respiratory disease].

We developed a new method of evaluating the tolerance for physical exercise in patients with chronic respiratory disease. Using a newly developed portable pulse oxymeter, with which we could measure kinetic energy (physical activity), calculated from the vertical acceleration involved in physical movements in the patient's daily life, we considered the correlation between the characteristics of the distribution of oxygen saturation (SpO2) and the degree of physical activity. The characteristics of SpO2 distribution in normal healthy subjects are uniform at all degrees of physical activity. In patients with chronic respiratory disease who complained of dyspnea on exertion, these characteristics became more uneven as physical activity increased. By comparing the characteristics of SpO2 distributions at rest with those at certain degrees of physical activity, we could quantitatively evaluate the exercise tolerance of patients with chronic respiratory disease, while monitoring their physical activity and SpO2 in daily life, without burdening the patients with stress such as would be imposed by the treadmill test. This new method is applicable for determining the indications for home oxygen therapy. Its application in home health care could offer a useful evaluation of a patient's activities of daily living and also early discovery of aggravation of chronic respiratory failure.