Biomedical subjects

C Chouaid

Publications and source records attributed to C Chouaid.

At least 37 records · Page 2Linked to original sources

PubMed1998

Polycythemia impairs vasodilator response to acetylcholine in patients with chronic hypoxemic lung disease.

To investigate whether polycythemia associated with chronic hypoxemic lung disease (CHLD) increases vascular resistance by altering endothelium-derived nitric oxide (NO), we examined the responses to acetylcholine (ACh) infusions (5, 10, and 15 mg/min) on hemodynamics and gas exchange in 21 patients with CHLD of varying severity. Patients were classified into two groups based on whether their hemoglobin (Hb) level was less or greater than 15.5 g/dl. In the normocythemic patients (Hb = 13.6 +/- 0.3 g/100 ml, n = 10), ACh decreased pulmonary artery pressure (Ppa) from 30 +/- 2 mm Hg 26 +/- 2 mm Hg (p < 0.01); pulmonary vascular resistance (PVR), from 5.1 +/- 0.4 U/m2 to 3.4 +/- 0.3 U/m2 (p < 0.001); systemic arterial pressure (Psa), from 111 +/- 4 mm Hg to 108 +/- 4 mm Hg (p < 0.05); and systemic vascular resistance (SVR), from 27 +/- 2 U/m2 to 22 +/- 2 U/m2 (p < 0.01); and also increased the cardiac index (CI), from 3.8 +/- 0.2 to 4.7 +/- 0.3 L/min/m2 (p < 0.001). PaO2 fell from 59 +/- 3 mm Hg to 48 +/- 3 mm Hg (p < 0.001) whereas venous admixture (Qs/Qt) rose from 32 +/- 4% to 44 +/- 4% (p < 0.01). In contrast, in patients with polycythemia (17.7 +/- 0.5 g/100 ml, n = 11) ACh failed to produce any changes in PaO2 (49 +/- 2 mm Hg versus 51 +/- 2 mm Hg, p = NS), Ppa (34 +/- 1 mm Hg versus 33 +/- 1 mm Hg, p = NS), PVR (6.7 +/- 0.9 U/m2 versus 6.9 +/- 0.8 U/m2, p = NS) or Psa, but slightly increased the CI, from 3.6 +/- 0.3 L/min/m2 to 3.9 +/- 0.3 L/min/m2 (p < 0.01), and Qs/Qt, from 40 +/- 4% to 45 +/- 3% (p < 0.05). In the 21 patients, negative correlations with Hb concentrations were found for ACh-induced changes in PVR (r = -0.57, p < 0.01), Ppa (r = -0.46, p < 0.01), CI (r = -0.5, p < 0.05), PaO2 (r = -0.79, p < 0.01), and Qs/Qt (r = -0.79, p < 0.01). In the six polycythemic patients who received isovolemic hemodilution, with a decrease in Hb concentration from 18.6 +/- 0.9 g/dl to 15.3 +/- 0.3 g/dl as a result, infusion of ACh, which was without effect before hemodilution, caused decreases in Ppa from 28 +/- 1 mm Hg to 23 +/- 1 mm Hg (p < 0.05) and in PVR from 5.7 +/- 0.8 U/m2 to 3.6 +/- 0.5 U/m2 (p < 0.02), as well as an increase in CI from 3.4 +/- 0.4 L/min/ m2 to 4.1 +/- 0.4 L/min/m2 (p < 0.05). In contrast to ACh, inhaled NO (40 ppm) induced pulmonary vasodilation in both the normocythemic and polycythemic groups. Our results show that high hematocrit (Hct) levels inhibit endothelium-dependent vasodilation in response to ACh in patients with CHLD, possibly through inactivation of endothelial-derived NO by Hb.

Acetylcholine↗

PubMed1998

CPAP titration by an auto-CPAP device based on snoring detection: a clinical trial and economic considerations.

This study aimed to assess the ability of an auto-nasal continuous positive airway pressure (nCPAP) device (REM + auto; NPBFD, Nancy, France) to predict the optimal constant nCPAP level. The apnoea/hypopnoea detection facility of the auto-nCPAP device was deliberately disabled and nasal mask pressure vibration detection was the only mode of pressure setting. The auto-nCPAP device was tested on 10 previously untreated patients with obstructive sleep apnoea during a single night, with ambulatory polysomnography performed in a conventional hospital room; the efficacy of the fixed pressure determined by the auto-nCPAP device was assessed by an ambulatory full polysomnography 2 weeks after the initiation of treatment at home. The fixed nCPAP pressure was effective (apnoea/hypopnoea and arousal indices <10 events x h(-1)) in all but two of the 10 patients studied. When the fixed nCPAP pressure was increased by 2 cmH2O in these two patients, sleep and respiration were normalized. Since only 12 ambulatory polysomnographic recordings were used to determine the effective nasal continuous positive airway pressure level, and as the device restored normal breathing and sleep in all 10 patients, it was concluded that this method of nasal continuous positive airway pressure titration may improve cost-effectiveness and reduce waiting lists in sleep laboratories.

Adult↗

PubMed1998

Routine use of granulocyte colony-stimulating factor is not cost-effective and does not increase patient comfort in the treatment of small-cell lung cancer: an analysis using a Markov model.

PURPOSE: The clinical indications and economic consequences of human granulocyte colony-stimulating factor (G-CSF) prescription during small-cell lung cancer (SCLC) chemotherapy remain controversial. The aim of this study, based on a Markov model, was to assess the impact of routine G-CSF use in the treatment of SCLC on costs and patient comfort. Markov models allow the modeling SCLC chemotherapy, in which the risk of febrile neutropenia (FN) is continuous over time and may occur more than once. PATIENTS AND METHODS: We used a Markov model to compare three strategies: a chemotherapy dose reduction after FN and nonuse of G-CSF ("never" strategy), secondary use of G-CSF ("CSF if FN" strategy) and primary use of G-CSF ("systematic CSF" strategy). Model baseline probabilities were based on a review of medical records for all patients (n = 39) treated for SCLC in our unit during 1993 (when G-CSF was not used) and on published reductions in the incidence of FN obtained by using G-CSF. Two different types of rewards were used: a cost-utility scale that took into account the costs of FN (CFN) episodes and G-CSF (CCSF) courses; and a comfort-utility scale that took into account the discomfort of FN and G-CSF therapy. Costs were analyzed from the health care payer's perspective and utilities were assessed prospectively in standardized interviews with treated SCLC patients. RESULTS: The never strategy was the least costly ($4,875 [United States] versus $5,816 and $7,690 for CSF if FN and systematic CSF) and gave the highest comfort value (378 U v 365 and 327 for CSF if FN and systematic CSF). Sensitivity analyses showed that the never strategy remains the less costly when the probability of a first FN episode was less than 49%, the probability of FN recurrence was less than 60%, or the CFN was less than $6,077, or the CCSF was greater than $863. In terms of patient comfort, the never strategy was the best choice, except for patients who considered that a course of G-CSF caused little or no discomfort, whether or not it prevented FN. CONCLUSION: Routine use of G-CSF during SCLC chemotherapy is not justified by clinical benefits, improved patient comfort, or economic considerations.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1998

[Thiamine deficiency. A cause of cardiac insufficiency not to be ignored].

Thiamine deficiency is one of the classical causes of high out put for heart failure. Deficiency of this vitamin may be nutritional or secondary to alcoholic intoxication. We felt it would be interesting to describe a typical case of cardiac beriberi in order to recall the clinical presentation and the pathophysiology.

Acidosis↗

PubMed1997

[Surgical pulmonary biopsies in patients with HIV infection: results apropos of a series of 21 cases].

This retrospective study reports the results of surgical lung biopsies in 21 patients infected by HIV. Diagnostic was assessed by surgical lung biopsies in 66% of cases with a 5% immediate post-operative mortality and a 80% survival rate after one month. Therapeutic management was modified in 38% of cases. These results are in concordance with previously published literature and emphasize that such a procedure should only be performed after other diagnostic procedures, including at least a bronchial endoscopy associated to a BAL and/or transbronchial biopsies.

Adult↗

PubMed1996

Efficacy and toxicity of mitomycin, ifosfamide, and cisplatin (MIP) in patients with inoperable non-small cell lung cancer.

Seventy-two patients with advanced stage IIIB (42%) or stage IV (58%) non-small cell lung cancer (median age 57 years, Karnofsky PS 60-100) were treated with mitomycin C (6 mg/m2, day 1), ifosfamide (1500 mg/m2, days 1-3), and cisplatin (30 mg/m2, days 1-3) every 4 weeks. The objective response rate was 37% in the overall population; 50% in stage IIIB patients and 29% in stage IV patients. Twenty four patients achieved partial response (33%) and three patients achieved complete response. Despite this relatively high objective response rate, the overall median survival time was 32 weeks. The median survival was significantly better in stage IIIB patients (55 weeks) than in stage IV patients (25 weeks) (P = 0.003). MIP regimen was permanently suspended in 14 patients because of toxic events. Seventeen patients developed grade III or IV febrile neutropenia and two patients died from sepsis. Two patients experienced acute mitomycin peumonitis. Despite increased doses of cisplatin and ifosfamide, compared with the original description for MIC chemotherapy, with probably higher toxicity, no apparent increased response rate or median survival was observed in this study. The MIP regimen could be tested in a randomized trial in comparison with other administration plans in a comparable population.

Adult↗

PubMed1996

Risk factors for isolation of Streptococcus pneumoniae with decreased susceptibility to penicillin G from patients infected with human immunodeficiency virus.

We conducted a retrospective study of all hospitalized human immunodeficiency virus (HIV)-infected patients from whom a strain of Streptococcus pneumoniae was isolated (n = 45) between January 1992 and September 1994, in order to determine the clinical manifestations and outcome of and risk factors for infection by S. pneumoniae with decreased susceptibility to penicillin G. Such strains were isolated from 14 patients (31%), of whom 8 had pneumonia, 2 had bronchial superinfection, 2 had sinusitis, and 2 were colonized. All infected patients made a clinical recovery regardless of the MIC of the isolate. Indexes of HIV disease stage (CD4+ cell count and p24 antigenemia), antiretroviral treatment, and hospital admission in the previous 3 months did not influence the susceptibility of the isolates. For HIV-infected patients, treatment with antibacterial agents--particularly trimethoprim-sulfamethoxazole--in the previous 3 months is associated with an increased risk for isolation of S. pneumoniae with decreased susceptibility to penicillin G (relative risk, 5.0; 95% confidence interval, 1.9-13.3).

AIDS-Related Opportunistic Infections↗

PubMed1996

[Diagnostic strategies of pulmonary pneumocystis infection in patients with HIV infection. Decision analysis and medico-economic consequences].

P. carinii pneumonia is one of the most frequent opportunistic infections in HIV-infected patients. Clinical and radiological manifestations are non-specific and reference diagnostic procedure remains broncho-alveolar lavage which is costly and invasive. Alternative diagnostic strategies have been proposed. We report here our experience as well as literature date in this field with the purpose to show the usefulness of decision analysis techniques in choosing an optimal cost-effective strategy.

AIDS-Related Opportunistic Infections↗

PubMed1995

[Clinical aspects and outcome of COPD].

Chronic obstructive pulmonary disease (COPD) is a frequent disease which is too often diagnosed when already severe. Major known risk factors are tobacco smoking, occupational exposure, and severe respiratory infections during childhood. Diagnostic should be evoked on functional non specific symptoms: chronic cough and sputum, progressive dyspnea. Some physical signs, correlated with the degree of airway obstruction, may be more specific but their diagnostic value remains to be assessed. These signs reflect distension of the chest as well as airway obstruction: pursed lips breathing, increased expiration duration, Hoover and Campbell signs, inspiratory contraction of scalen muscles. COPD results over years in chronic respiratory insufficiency and evolution is associated with episodes of bronchial and parenchymal infections as well as pulmonary emboli which are particularly frequent in these patients.

Adult↗

PubMed1995

Use of the polymerase chain reaction technique on induced-sputum samples for the diagnosis of Pneumocystis carinii pneumonia in HIV-infected patients. A clinical and cost-analysis study.

The purpose of this study was to assess the sensitivity and specificity of the polymerase chain reaction (PCR) on induced sputum (IS) for the diagnosis of Pneumocystis carinii pneumonia (PCP) in HIV-infected patients, as well as its diagnostic value and cost as a routine clinical tool. Forty-nine patients with suspected PCP who had IS were studied and if negative, followed by bronchoalveolar lavage (BAL). Pneumocystis carinii was detected in these samples using standard staining techniques. Polymerase chain reaction was used with IS samples in a blinded fashion. The patients with negative BAL samples were closely monitored for 1 month. In the absence of any clinical or radiologic features of PCP during this period, they were considered as being free of PCP. The cost analysis considered only the direct costs of the various tests in three diagnostic strategies: routine BAL (BAL); IS with standard staining, if negative, followed by BAL (IS); and IS with standard staining followed, if negative, by PCR on IS samples (PCR-IS). Using standard staining P carinii was found in 13 cases (6 IS and 7 BAL). None of the 36 patients with negative BAL developed further signs of PCP. Thus, the prevalence of PCP was 26.5% and the sensitivity and specificity of BAL were 100%. Standard staining of IS had a specificity of 100% and a sensitivity of 46.5%. The sensitivity and specificity of PCR-IS were each 100%. The costs of strategies BAL, IS, and PCR-IS were $14,010, $18,300, and $18,040, respectively. The costs of the BAL strategy depended only on the cost of the relevant tests, whereas the costs of strategies IS and PCR-IS depended on the costs of the tests, the sensitivity of IS with standard staining, and the prevalence of PCP in the test population. The routine clinical use of PCR-IS is currently limited by the time required to obtain the results.

AIDS-Related Opportunistic Infections↗

PubMed1995

Pulmonary cryptococcosis: localized and disseminated infections in 27 patients with AIDS.

We reviewed the records of 85 patients infected with both human immunodeficiency virus and Cryptococcus neoformans. Twenty-seven patients (32%) had pulmonary cryptococcosis. C. neoformans was cultured from bronchoalveolar lavage (BAL) or pleural fluid in 25 cases; the remaining two patients had cryptococcal antigen (CA) detected in BAL fluid and C. neoformans cultured from other sites. All but one of the 27 patients had detectable CA in serum. The CD4+ lymphocyte count was low in all cases (median, 24/mm3). Clinical manifestations of pulmonary cryptococcosis included fever (94%), cough (71%), dyspnea (7%), expectoration (4%), chest pain (2%), and hemoptysis (1%). Diffuse interstitial opacities (70.5%), focal interstitial abnormalities, alveolar opacities, adenopathies, cavitary lesions, and pleural effusions were evident. Outcome was poor (mean survival time, 23 weeks) despite treatment. Patients with localized pulmonary cryptococcosis appeared to have a higher CD4+ lymphocyte count, an earlier diagnosis, lower serum CA titers, fewer previous or concomitant infections, and a better prognosis than patients with disseminated cryptococcosis.

AIDS-Related Opportunistic Infections↗

PubMed1995

Pulmonary toxoplasmosis in HIV-infected patients: usefulness of polymerase chain reaction and cell culture.

Toxoplasmosis is a serious opportunistic infection in patients with acquired immunodeficiency syndrome (AIDS). The lung is a major site of infection after the central nervous system. The aim of the study was to assess the polymerase chain reaction (PCR) and cell culture for the detection of Toxoplasma gondii. One hundred and thirty two human immunodeficiency virus (HIV)-infected patients with respiratory manifestations, who underwent fibreoptic bronchoalveolar lavage, were investigated. Detection of Toxoplasma gondii was compared using three techniques: Giemsa staining; polymerase chain reaction with specific primers derived from the P30 gene; and culture on the MRC5 cell line. Toxoplasma gondii was detected in the same four samples by all three techniques. We conclude that PCR adds little to conventional (and cheaper) tools already used to diagnose pulmonary toxoplasmosis.

AIDS-Related Opportunistic Infections↗

PubMed1995

[Allopurinol hypersensitivity. A possible cause of hepatitis and mucocutaneous eruptions in a patient undergoing antitubercular treatment].

The authors describe a case of drug-induced cytolytic hepatitis probably secondary to hypersensitivity to allopurinol which was prescribed incorrectly for secondary hyperuricaemia during treatment with pyrazinamide. The diagnosis was reviewed in view of the late occurrence of hepatitis in relation to the onset of the antituberculous treatment, the absence of a viral aetiology and the presence of clinical manifestations, biological and histological features which were compatible with hypersensitivity to allopurinol. The authors recalled that the type of uricaemia induced by pyrazinamide is most often asymptomatic and does not require any treatment with uric acid lowering drugs. Cessation of pyrazinamide is justified in cases of symptomatic hyperuricaemia but when the indications for pyrazinamide are imperative, treatment with an eliminator of uric acid is indicated. Allopurinol is contra-indicated in association with pyrazinamide on account of its inhibitory reaction to xanthine oxidase. Xanthine oxidase decreases the level pyrazinoic acid, a metabolite of pyrazinamide, which is responsible for the inhibition of the tubular secretion of uric acid.

Adult↗

PubMed1995

Cost-analysis of four diagnostic strategies for Pneumocystis carinii pneumonia in HIV-infected subjects.

The aim of this study was to analyse the cost-effectiveness ratio of four diagnostic strategies for Pneumocystis carinii pneumonia (PCP) in patients infected with human immunodeficiency virus (HIV). Two hundred and ten HIV-infected patients with suspected PCP underwent induced-sputum (IS) followed, if negative, by bronchoalveolar lavage (BAL); 85 of these patients were able to undergo an exercise test (ET), prior to induced sputum and BAL. The following strategies were analysed: BAL strategy (BAL whenever PCP is suspected); IS strategy (induced sputum followed by BAL if negative); exercise test (ET) strategy, (ET followed by BAL if the results are abnormal); and the ES (exercise sputum) strategy (i.e. BAL only after abnormal ET and negative IS). The cost of each strategy was calculated by taking into account only direct costs; the conditions in which two given strategies would be cost-equivalent were also evaluated. The prevalence of PCP in this population was 31%; IS had 100% specificity and 71% sensitivity, whilst ET had 100% sensitivity and 77% specificity. The costs of BAL, IS, ET and ES strategies were 210,000, 191,940, 140,700 and 112,700 FF, respectively. The ES strategy is, thus, most suitable for our unit. The most economic strategy depends not only on the cost and characteristics of the procedures, but also on the prevalence of PCP in the test population. In conclusion, we developed a model for use by diagnostic centres in choosing the most suitable strategy, on the basis of the local prevalence of PCP.

AIDS-Related Opportunistic Infections↗

PubMed1994

Attitudes to prevention among HIV-infected patients: the case of specific prophylaxis for Pneumocystis carinii pneumonia.

Despite a consensus on the need for Pneumocystis carinii pneumonia (PCP) prophylaxis for HIV-infected patients with fewer than 200 CD4+ lymphocytes/mm3, the number of cases of PCP has remained stable, and about 70% involve patients who are not receiving prophylaxis. The aim of this study was to determine why these patients are not covered by prophylaxis. It was based on a retrospective analysis of semidirective interviews with 32 patients who developed PCP while not receiving prophylaxis. The reasons given were a lack of knowledge of risk factors for HIV infection, the fear of HIV testing, unawareness of the existence of PCP prophylaxis, a refusal to see a doctor in the absence of symptoms, unwillingness to be monitored and in four cases a failure of the doctor to prescribe prophylaxis.

Adult↗

PubMed1994

Usefulness of PCR for detection of Pneumocystis carinii DNA.

Diagnosis of Pneumocystis carinii pneumonia is based on the identification of the various stages of the parasite in lung samples by standard staining techniques. We therefore assessed the value of the PCR for detection of P. carinii in bronchoalveolar lavage, induced sputum, and blood samples relative to that of standard staining techniques.

AIDS-Related Opportunistic Infections↗

PubMed1993

[Consequences of specific prevention on the diagnosis of Pneumocystis carinii pneumonia in patients with HIV infection. Comité SIDA de l'Hôpital Saint-Antoine].

In a prospective study the authors compared the clinical, radiological, biochemical and diagnostic features of Pneumocystis carinii pneumonia (PCP) in HIV-infected patients who were or were not receiving a specific prophylactic treatment. The study included 386 patients with suspected PCP, 201 of whom were under specific prophylactic therapy. Induced expectoration and/or bronchoalveolar lavage provided a diagnosis of PCP in 89 patients, 21 of whom were under specific prophylaxis. Apart from a number of circulating CD4 lymphocytes that was significantly lower in the patients under prophylaxis, there was no significant difference between the two groups. Thus, being under specific prophylaxis should have no effect on the diagnosis of PCP in HIV-infected patients.

AIDS-Related Opportunistic Infections↗

PubMed1993

Cost effectiveness of noninvasive oxygen saturation measurement during exercise for the diagnosis of Pneumocystis carinii pneumonia.

We assessed (1) the sensitivity and specificity of exercise oxygen saturation measurement (EOS) for the diagnosis of Pneumocystis carinii pneumonia (PCP); and (2) the cost of introducing this indirect diagnostic test compared with that of standard diagnostic strategies for PCP. In a prospective study, 85 HIV-infected patients with suspected PCP underwent EOS, followed by induced sputum (IS) and bronchoalveolar lavage (BAL) if IS was negative for P. carinii. The prevalence of PCP was 0.22, the sensitivity of IS was 0.6, and its specificity was perfect. The cost ratios of IS to BAL and EOS to BAL were 0.1 and 0.2, respectively. A desaturation of three points was the best cutoff point, giving perfect sensitivity and a specificity of 0.77. The cost analysis showed that the introduction of EOS into diagnostic strategies for PCP is highly justified when the local prevalence is low. Exercise oxygen saturation measurement is simple and safe, and the results are available rapidly; its sensitivity is perfect and its specificity good. Its economic utility depends on its cost and the local prevalence of PCP in the test population.

AIDS-Related Opportunistic Infections↗