A systematic review of the epidemiology, immunopathogenesis, diagnosis, and treatment of pleural TB in HIV-infected patients.

BACKGROUND: High HIV burden countries have experienced a high burden of pleural TB in HIV-infected patients. OBJECTIVE: To review the epidemiology, immunopathogenesis, diagnosis, and treatment of pleural TB in HIV-infected patients. METHODS: A literature search from 1950 to June 2011 in MEDLINE was conducted. RESULTS: Two-hundred and ninety-nine studies were identified, of which 30 met the inclusion criteria. The immunopathogenesis as denoted by cells and cytokine profiles is distinctly different between HIV and HIV-uninfected pleural TB disease. Adenosine deaminase and interferon gamma are good markers of pleural TB disease even in HIV-infected patients. HIV-uninfected TB suspects with pleural effusions commonly have a low yield of TB organisms however the evidence suggests that in dually infected patients smear and cultures have a higher yield. The Gene Xpert MTB/RIF assay has significant potential to improve the diagnosis of pleural TB in HIV-positive patients. CONCLUSIONS: Pleural TB in HIV-infected patients has a different immunopathogenesis than HIV-uninfected pleural TB and these findings in part support the differences noted in this systematic review. Research should focus on developing an interferon gamma-based point of care diagnostic test and expansion of the role of Gene Xpert in the diagnosis of pleural TB.

Mechanisms of dyspnoea relief and improved exercise endurance after furosemide inhalation in COPD.

BACKGROUND: This study examined the effects of inhaled furosemide on the ventilatory and perceptual response to high-intensity constant-load cycle exercise in chronic obstructive pulmonary disease (COPD). METHODS: In a randomised, double-blind, placebo-controlled, crossover study, 20 patients with COPD (mean (SD) forced expiratory volume in 1 s 45 (15)% predicted) received either nebulised furosemide 40 mg or placebo on two separate days. Thirty minutes after each treatment, patients performed pulmonary function tests and a symptom-limited cycle exercise test at 75% of their maximum incremental work rate. Changes in spirometry, plethysmographic lung volumes, dynamic operating lung volumes, ventilation, breathing pattern, cardiovascular function, dyspnoea intensity and exercise endurance time were compared between treatments. RESULTS: Compared with placebo, treatment with furosemide resulted in a mean (SD) decrease in dyspnoea intensity at the highest equivalent exercise time (ie, isotime for each patient) of 0.9 (1.0) Borg units (p<0.01) and an increase in exercise endurance time of 1.65 (0.63) min (p<0.05). These improvements were associated with increases in dynamic inspiratory capacity, tidal volume and mean tidal expiratory flow rates at isotime (p<0.01). The eight patients whose exercise endurance time improved by >1 min had greater changes in operating lung volumes (p<0.05), submaximal oxygen pulse (p<0.05) and oxygen uptake (p = 0.05) than those in whom exercise endurance time did not improve. CONCLUSION: Alleviation of exertional dyspnoea after single-dose furosemide inhalation in COPD is multifactorial but improvements in dynamic ventilatory mechanics are contributory in some individuals.

Mechanisms of exertional dyspnea in patients with cancer.

Exertional dyspnea is an important symptom in cancer patients, and, in many cases, its cause remains unexplained after careful clinical assessment. To determine mechanisms of exertional dyspnea in a variety of cancer types, we evaluated cancer outpatients with clinically important unexplained dyspnea (CD) at rest and during exercise and compared the results with age-, sex-, and cancer stage-matched control cancer (CC) patients and age- and sex-matched healthy control participants (HC). Participants (n = 20/group) were screened to exclude clinical cardiopulmonary disease and then completed dyspnea questionnaires, anthropometric measurements, muscle strength testing, pulmonary function testing, and incremental cardiopulmonary treadmill exercise testing. Dyspnea intensity was greater in the CD group at peak exercise and for a given ventilation and oxygen uptake (P < 0.05). Peak oxygen uptake was reduced in CD compared with HC (P < 0.05), and breathing pattern was more rapid and shallow in CD than in the other groups (P < 0.05). Reduced tidal volume expansion during exercise correlated with reduced inspiratory capacity, which, in turn, correlated with reduced inspiratory muscle strength. Patients with cancer had a relatively reduced diffusing capacity of the lung for carbon monoxide, reduced skeletal muscle strength, and lower ventilatory thresholds during exercise compared with HC (P < 0.05). There were no significant between-group differences in measurements of airway function, pulmonary gas exchange, or cardiovascular function during exercise. In the absence of evidence of airway obstruction or restrictive interstitial lung disease, the shallow breathing pattern suggests ventilatory muscle weakness as one possible explanation for increased dyspnea intensity at a given ventilation in CD patients.

Stenting allows weaning and extubation in ventilator- or tracheostomy dependency secondary to benign airway disease.

Central airway obstruction can cause severe respiratory insufficiency leading to mechanical ventilation (MV) or artificial airway (AA) dependency. Interventional bronchoscopic procedures have been reported to be of help in weaning patients with malignant airway stenoses from mechanical ventilation, whereas their use in benign disease is only anecdotal. The objectives of this study are to evaluate early, intermediate and long-term outcome of interventional bronchoscopy and stent placement in the treatment of MV/AA dependency due to benign airway obstruction. In a retrospective cohort analysis for the period 1999-2004, we evaluated 15 consecutive ICU patients with documented benign central airway obstruction, who were referred for bronchoscopic management of their condition after multiple failed attempts at weaning from MV or decannulation of the AA. Indications for bronchoscopic treatment were surgery refusal, medical or surgical inoperability, or absence of alternative treatment options. Malacia, post-intubation stenosis and goiter were the main causes of airway obstruction and MV/AA dependency. All patients were treated by means of rigid bronchoscopy, dilatation procedures and stent insertion. All but one patient (93.3%) were successfully and permanently extubated/decanulated immediately after the bronchoscopy. Minor complications occurred in 6 patients (40%) leading to a second intervention. All complications could be managed endoscopically and long-term follow up was uneventful. Interventional bronchoscopy with stent insertion can allow successful withdrawal from MV/AA and can offer longstanding airway patency in selected ventilator- or tracheostomy-dependant individuals with benign airway stenoses,when surgery in not feasable or contra-indicated.

Anterior rectal duplication: a diagnostic challenge.

The authors present an anterior rectal cyst in a 14-month-old girl. This rare variant of rectal duplications presented with recurrent urinary infections. The diagnosis was challenging in view of the multiple differential diagnoses to be considered. Magnetic resonance imaging appeared to be the most accurate preoperative investigation. The cyst was removed uneventfully by partial excision and mucosal ablation. An awareness of this variant can lead to early diagnosis and curative resection.

Familial occurrence of pseudoexfoliation in Canada.

BACKGROUND: Genetic factors may play an important role in pseudoexfoliation syndrome. We describe the familial occurrence of pseudoexfoliation in Canadian families. METHODS: Probands with pseudoexfoliation were referred to a tertiary care glaucoma service in Ottawa because of a family history of pseudoexfoliation or glaucoma, or both. Probands and family members who agreed to participate underwent a systematic interview and eye examination. The pseudoexfoliation status was classified as affected, suspect or unknown based on preestablished criteria for the diagnosis of pseudoexfoliation and glaucoma. RESULTS: Thirty-four members of 10 families were assessed (18 affected, 2 suspect and 14 status unknown). Six families had two or more generations with pseudoexfoliation, and four families had one generation affected. There was a predominance of females among the affected subjects (17:1), and transmission in all cases appeared to be maternal. Eight of the families were of Irish/Scottish ancestry. Nine (50%) of the affected subjects had cardiovascular disease. Affected subjects tended to be older than suspects and those whose status was unknown (mean age 77, 67 and 55 years respectively). Seven subjects were affected unilaterally and 11 bilaterally. Affected subjects had moderate angle pigmentation in both eyes (mean +2.7, where 0 = no pigment and +4 = dense homogeneous pigment). The mean intraocular pressure in both eyes was higher for the affected subjects (23.1 [standard deviation (SD) 8.6] mm Hg) than for the suspects (16.8 [SD 6.1] mm Hg) and those of unknown status (16.8 [SD 2.9] mm Hg). An enlarged cup:disc ratio was seen in the affected subjects (mean 0.62). Eleven (61%) of the affected subjects had open angles on gonioscopy, and five had occludable angles and required peripheral iridectomy. Ten (56%) of the affected subjects were classified as having glaucoma, and 14 (78%) had evidence of cataract formation in at least one eye. INTERPRETATION: Pseudoexfoliation appears to be transmitted matrilineally, which raises the possibility of mitochondrial inheritance, X-linked inheritance or autosomal inheritance with genomic imprinting. A larger study of families with pseudoexfoliation is necessary to clarify the mode of transmission and to identify the gene(s) involved in the etiology of this disorder.