Intensive respiratory care in patients with myasthenic crisis

Six patients received mechanical ventilation for 8 episodes of myasthenic crisis in a two year period. Median duration of ventilation was 8 days. Only one patient required ventilation for more than three weeks and underwent tracheostomy. Atelectasis and pneumonia were the common ventilator associated complications observed, and these responded to therapy. Two patients underwent thymectomy after initial stabilization and while being ventilated. All patients recovered completely.

Development of a simple computer program for spirometry interpretation

OBJECTIVES

To develop and evaluate a computer program for interpretation of spirometry.

METHODOLOGY

The spirometry programme was constructed in Epi Info software using a previously defined algorithm for interpretation. The programme incorporated current American Thoracic Society guidelines on interpretation of spirometry and was based on regression equations for healthy North Indians previously derived by us. The programme was pretested for two months before being put to routine use.

RESULTS

Use of this spirometry programme led to consistent interpretation of spirometry results. There was significant saving of time while preparing reports, without any additional expenditure.

CONCLUSION

The use of such computer programmes accelerate the reporting of pulmonary function test results at little extra cost, and all interpretations are performed in a consistent fashion.

Radiographic patterns in lung cancer

Three hundred seventy three previously diagnosed patients with lung cancer, attending the Lung Cancer Clinic at this institute were studied. Chest radiographs were interpreted in all cases. Radiography was compared in different cell types. Squamous cell carcinoma 158 (42.4%), followed by small cell lung cancer 122 (32.7%), was the commonest histological subtype. Upper zone was involved in maximum number of cases 158 (42%), followed by mid zone 122 (32.7%), lower zone 60 (16%) and the entire lung 33(8.8%). Adenocarcinoma presented as a peripheral mass in 37 (61%) cases and in 23 (38.3%) as a central lesion. Presentation as a central mass (114, 72.2% cases) was more common among squamous cell carcinoma than as a peripheral lesion (44, 27.8% cases). Similarly, small cell cancer also presented more commonly as a central lesion (102, 83.6% cases) than as a peripheral lesion (20, 16.4% cases). Isolated pleural effusion was present in 3.8% in squamous cell lung cancer, 22% in adenocarcinoma and only 4% in small cell lung cancer.

Static lung compliance as an index of early pulmonary disease in systemic sclerosis

Pulmonary function abnormalities constitute the most important cause of morbidity and mortality in patients with systemic sclerosis (SSc). A restrictive ventilatory defect with a reduction in pulmonary carbon monoxide diffusion capacity (DLCO) is the commonest finding. Static lung compliance (Cst) is perhaps the most sensitive parameter for the detection of abnormal pulmonary mechanics. We compared the results of Cst and DLCO in patients with SSc and normal spirometry to identify early pulmonary disease. Sixteen of 50 patients had normal spirometry, eight of whom had abnormal Cst. Four of them also had a reduced DLCO. Two patients had abnormal DLCO but their Cst was normal. One of them had pulmonary hypertension on echocardiography. We conclude that Cst was helpful in diagnosing early pulmonary abnormality in 50% of patients with normal spirometry. Among these patients Cst was a better index of abnormality than DLCO.

Dust-induced interstitial lung disease in the tropics

Inhalation of dusts is an important cause of interstitial lung disease in the tropical countries such as India. While dusts of organic origin, such as the cotton dust causing byssinosis, generally cause bronchial or bronchiolar involvement and hypersensitivity pneumonitis, inorganic metallic dusts cause progressive pulmonary fibrosis. Silicosis, coal workers' pneumoconiosis, and asbestosis are the three most commonly recognized forms of pneumoconiotic pulmonary fibrosis. Pulmonary tuberculosis is an important complication seen in up to 50% of patients of silicosis in some reports from India. The presentation is generally chronic, although acute and accelerated forms of silicosis are known when the exposures are heavy. Breathlessness, dry cough, and general constitutional symptoms are commonly seen. Patients with silicotuberculosis or other forms of infection may also have significant expectoration, hemoptysis, fever, and rapid progression. Respiratory failure and chronic cor pulmonale occur in the later stages. The diagnosis is easily established if the occupational history is available. Dense nodular opacities on chest roentgenograms, which may be large in patients with massive pulmonary fibrosis, are characteristic. Emphysematous changes generally appear in advanced stages or in patients who smoke. Bronchoalveolar lavage and/or lung biopsy may occasionally be required to establish or exclude other causes of interstitial lung disease. Treatment is largely palliative, although a variety of drugs including corticosteroids and procedures such as whole lung lavage have been tried. None of these methods has yet been found successful in the treatment. Preventive safety steps, including removal of the patient from the site of exposure, are the only effective strategies to control disease progression.

Prevalence of bronchial asthma and association with environmental tobacco smoke exposure in adolescent school children in Chandigarh, north India

Prevalence of asthma and its association with environmental tobacco smoke (ETS) exposure were examined among adolescent schoolchildren in Chandigarh, India. Using a previously standardized questionnaire, data from 9090 students in the 9- to 20-year age range were analyzed. There were 4367 (48%) boys, in whom the observed prevalence of asthma was 2.6%. Among 4723 (52%) girls, asthma was present in 90 (1.9%) students. Presence of one or more respiratory symptoms was reported by 31% students. More students with asthma had either parents or other family members smoking at home as compared to nonasthmatics (41% vs. 28%, p<0.0001). The odds ratio for being asthmatic for patients exposed to ETS compared to those not exposed to ETS was 1.78 (95% confidence interval 1.33-2.31). ETS was also positively associated with prevalence of all the respiratory symptoms, with odds ratios varying between 1.6 and 2.25.

A review of population studies from India to estimate national burden of chronic obstructive pulmonary disease and its association with smoking

An attempt has been made to estimate the gross burden of chronic obstructive pulmonary disease (COPD) and its smoking association by reviewing the population studies available from India. Of the 14 studies which were reviewed, there were 11 conducted in general populations. The median values of different prevalence rates (i.e. 5 percent in male and 2.7 percent in female population) were accepted as the most appropriate figures to calculate the overall estimates. The overall M:F ratio was 1.6:1, i.e. 61.6 percent males. The estimated total number of adult patients aged 30 years and above in 1996 were 8.15 million males and 4.21 million females. The smoker:non-smoker ratio in males was assessed at 82.3 percent with an estimated burden of 6.7 millions. When the prevalence rates of COPD and its smoking associations were assessed in three different time periods (before 1970; between 1971-1990; after 1990), the median rates of 1971-1990, when the maximum number of studies were conducted, were nearly the same as the overall rates. However, the total burden as well as the smoking associated COPD, increased with time due to an increase in the eligible base population. In conclusion, these figures can be used to estimate the burden of COPD and its smoking association in India for different statistical analyses.

Evaluation of polymerase chain reaction for detection of Mycobacterium tuberculosis in pleural fluid

OBJECTIVES

Tuberculosis, a reemergent killer, is threatening to assume serious proportions all over the world, particularly in view of the AIDS pandemic. The detection of mycobacterial DNA by polymerase chain reaction (PCR) in clinical samples is a promising approach for the rapid diagnosis of tuberculous infections. The aims of this study were to evaluate PCR for detection of Mycobacterium tuberculosis in pleural fluids and to correlate the results with adenosine deaminase activity (ADA) estimation and acid-fast bacilli (AFB) screening.

METHODS

The sensitivity and specificity of PCR in detection of mycobacterial DNA in 20 samples of tuberculous pleural effusion were evaluated using 40 samples of nontubercular pleural effusion as controls. The results were correlated with the ADA in all 60 pleural fluids. In addition, AFB detection by Ziehl-Neelsen staining on cytospin smears of all pleural fluids was also compared.

RESULTS

Of the 20 samples of tuberculous pleural effusion, mycobacterium could be detected by AFB staining in 4 samples. Fourteen samples were PCR positive. None of the samples from the control group were AFB or PCR positive. The sensitivity of PCR, therefore, was 70.0% with specificity of 100% (positive predictive value, 100%; negative predictive value, 86.95%). The sensitivity of AFB screening was at best 20%. The mean of ADA values in tubercular pleural effusions was 63.21 U/L (SD, 33.01), and the mean in the control samples was 51.1 U/L (SD, 29.71). Taking a cut-off value of 50 U/L, both the sensitivity and specificity of ADA estimation in diagnosing tuberculosis were only 55%.

CONCLUSION

PCR represents a rapid and sensitive method for the detection of mycobacterial DNA in tuberculous pleural effusions. AFB screening has low sensitivity, and ADA estimation has both low sensitivity and specificity. Therefore, when the clinical suspicion is high and smear result is negative, but the signs and symptoms of M tuberculosis are apparent, PCR is the method of choice for identifying the infection.

Assessment of factors predicting outcome of acute respiratory distress syndrome in North India

OBJECTIVES

Information on the spectrum and outcome of acute respiratory distress syndrome (ARDS) in tropical countries is scanty. This study was designed to assess the factors predicting the outcome of ARDS in North India.

METHODOLOGY

Consecutive patients requiring mechanical ventilation for ARDS over a 2 year period at the Respiratory Intensive Care Unit (RICU) of a tertiary referral hospital were studied. Hospital survival was correlated with age, aetiology, disease severity scores (APACHE III, SAPS II, lung injury score) and organ failure using univariate analysis. Factors significantly influencing mortality were examined by multivariate analysis to identify factors independently affecting outcome.

RESULTS

Sepsis (28.6%), followed by malaria (21.4%), were the commonest risk factors. Seven out of eight patients (87.5%) with sepsis died. The presence of sepsis, more than three organ failure prior to admission, APACHE III score > 57 and SAPS II score > 39 were significantly associated with mortality. Only APACHE III score > 57 or SAPS II score > 39 were, however, independently predictive of a poor outcome following multivariate analysis.

CONCLUSIONS

Sepsis, associated with a very poor outcome, and malaria were important risk factors for the development of ARDS. APACHE III score > 57 or SAPS II score > 39 were associated with increased risk of mortality.

Increased nitric oxide production by neutrophils in bronchial asthma

This study was designed to assess the production of nitric oxide (NO) by neutrophils in bronchial asthma. Thirty asthmatic patients (ten each of mild, moderate and severe asthma) and ten healthy controls were included in the study. Neutrophils from peripheral venous blood were stimulated with latex, and production of nitrite (an NO metabolise) and L-citrulline (a co-product of NO) was studied. It was postulated that peripheral blood neutrophils, being in a primed or activated state in asthma, would reflect the changes occurring in bronchial tree neutrophils. Nitrite and L-citrulline production by neutrophils was significantly higher in asthmatics (p < 0.001) and increased with disease severity. A strong negative correlation was observed between peak expiratory flow and both nitrite (r = -0.87, p < 0.001) and L-citrulline (r = -0.88, p < 0.001) production. It is concluded that nitric oxide production by neutrophils is increased in bronchial asthma and can possibly contribute to airway narrowing and disease severity.

Static lung mechanics in patients of progressive systemic sclerosis without obvious pulmonary involvement

Pulmonary fibrosis is a common complication in progressive systemic sclerosis (PSS). Physical examination and/or routine pulmonary function tests can, however, detect only relatively advanced disease. We assessed the utility of static lung pressure-volume analysis in detecting lung involvement in patients of PSS without obvious clinical, radiological or spirographic evidence of pulmonary disease. Static lung volumes were determined and expiratory lung pressure-volume measurements were obtained in 10 patients with PSS, using a computerized whole body plethysmograph. Static pressure-volume data was also subjected to monoexponential analysis. All patients had normal total lung capacity. Three patients had reduced static compliance, of whom one also had reduced value for the shape constant K (calculated from exponential analysis of pressure-volume data). Examination of pressure volume curve showed a pattern consistent with interstitial fibrosis in these patients. We conclude that detailed study of lung mechanics can help identify early pulmonary involvement in patients with PSS.

Risk factors of lung cancer in Chandigarh, India

BACKGROUND & OBJECTIVES

There is a paucity of data from India on the risk factors for lung cancer. In the present paper results of a case-control study on lung cancer undertaken at Chandigarh, north India, are described.

METHODS

Two hundred and sixty five (235 men, 30 women) histologically confirmed patients of lung cancer and 525 (435 men, 90 women) hospital controls matched for age and sex were interviewed according to a pre-designed questionnaire. Effects of individual variables defining the various aspects of tobacco smoking, indoor and outdoor air pollution and occupational exposures were assessed using unconditional logistic regression models.

RESULTS

Eighty nine per cent of men and 33 per cent of women among the patients were ever-smokers as compared to 60 per cent of men and 20 per cent of women among controls. The Odds Ratio (OR) for ever-smoking was 5.0 (CI 3.11-8.04) among men and 2.47 (CI 0.79-7.75) among women. Among the patients, men were found to smoke a higher average number of cigarette-equivalents per day, for longer duration and started at an earlier age as compared to controls. Smoking of bidi and hooka as well as cigarettes had similar ORs for cumulative consumption. ORs for female smokers were lower than those for male smokers. Cumulative exposure of > 45 yr in women to indoor air pollution from use of coal or wood for cooking or heating showed an OR of 1.43 (CI 0.33-6.30). Residence in urban areas did not entail an increased risk for developing lung cancer. Very few subjects studied were employed in high-risk occupations.

INTERPRETATION & CONCLUSIONS

Smoking (cigarettes or bidis) was the principle risk factor for causation of lung cancer among men. In women there could be several other risk factors besides smoking, as the association with smoking was not as strong.

Use of static lung mechanics to identify early pulmonary involvement in patients with ankylosing spondylitis

AIM

To assess if a detailed analysis of lung mechanics could help in early recognition of pulmonary abnormalities in patients with ankylosing spondylitis.

METHODS

Static pulmonary mechanics were studied in 17 patients (16 men and one woman) of ankylosing spondylitis with no obvious clinical or radiological evidence of pulmonary involvement. Lung pressure-volume relationship was generated using a whole body plethysmograph, and a monoexponential equation fitted to this data.

RESULTS

Total lung capacity (TLC) was reduced in one (5.9%) and static lung compliance (Cst) in nine (52.9%) patients. Four (23.5%) patients had normal TLC, yet Cst and shape constant (K) were reduced. Five (29.4%) patients had reduced TLC and Cst; four of them had low K. One (5.9%) patient had normal TLC but elevated Cst and K.

CONCLUSIONS

Pulmonary involvement in patients with ankylosing spondylitis is probably diffuse and begins much earlier than generally presumed. Evaluation of static lung mechanics can identify pulmonary involvement early in the course of disease in several of these patients.

Value of different cut-off points of tuberculin skin test to diagnose tuberculosis among patients with respiratory symptoms in a chest clinic

OBJECTIVE

To assess the utility of various cut-off points of tuberculin skin test in making a diagnosis of tuberculosis in patients with respiratory symptoms.

METHODS

Tuberculin skin test was conducted on consecutive new patients attending chest clinic for various respiratory symptoms. All subjects were then investigated to establish diagnosis, and categorized into tuberculous and nontuberculous groups. Receiver operating characteristic (ROC) curve was plotted to evaluate discrimination by tuberculin skin test. Sensitivity, specificity and predictive value were also calculated at various cut-off points.

RESULTS

Of 250 patients, 59 (23.6%) had tuberculosis on clinical and microbiological criteria (other than the tuberculin test). Sensitivity and specificity of tuberculin test at readings greater than 5, 10 and 15 mm were 0.8136 and 0.7068, 0.6271 and 0.8901, and 0.2034 and 0.9738 respectively. Area under ROC curve for this test was 0.80.

CONCLUSION

A cut-off point of 10 mm is likely to be useful in supporting a diagnosis of tuberculosis in patients with strong clinical suspicion of tuberculosis, in other patients, 15 mm cut-off may be more suitable.

Radioisotope scintigraphy in the diagnosis of hepatic hydrothorax

BACKGROUND

Pleural effusion in cirrhotic patients (hepatic hydrothorax) may result from migration of ascitic fluid across defects in the diaphragm. Biochemical analysis of ascitic and pleural fluid provides only indirect information about the nature and origin of the effusion. The present study was performed in order to demonstrate the presence/absence of peritoneo-pleural communication by radioisotope imaging.

METHODS

Ten patients with cirrhotic ascites and pleural effusion were studied with 99mTc sulfur colloid scintigraphy to look for movement of the radiotracer from the peritoneal to the pleural cavity. Serum-ascitic albumin gradient (SAAG) and serum-pleural fluid albumin gradient (SPAG) values were determined in eight patients to examine the nature of the ascitic and pleural fluids.

RESULTS

Transdiaphragmatic movement of ascitic fluid into the pleural space was demonstrated (generally within 2 h of intraperitoneal injection of the radiotracer) in eight of 10 patients; six on the right side, one on the left and one bilaterally. Two patients in whom pleural fluid was transudative on SPAG values were negative for peritoneo-pleural communications.

CONCLUSIONS

Radionuclide scintigraphy is a simple, safe and relatively non-invasive method to confirm passage of ascitic fluid across the diaphragm.

Management of respiratory failure in severe neuroparalytic snake envenomation

Fourteen patients with severe neuroparalytic snake envenomation, resulting in acute type II respiratory failure, admitted to respiratory critical care unit for mechanical ventilation during one year period, were studied. Ventilatory requirements, amount of anti snake venom (ASV) infused, period of neurological recovery and hospital survival were evaluated. All patients had severe manifestations such as ptosis, extraocular muscle paresis and limb weakness along with dyspnoea. Seven patients (50%) had additional complaints of dysphagia and dysphonia. ASV was administered to all, with a median requirement of 900 ml. Mechanical ventilation was required for a median duration of 17 hours and all except one patient, who had suffered irreversible hypoxic cerebral injury prior to resuscitation, survived with complete neurological recovery. We conclude, that the timely institution of ventilatory support and anti-venom therapy in such patients, is associated with an excellent outcome.

Aggressive atropinisation and continuous pralidoxime (2-PAM) infusion in patients with severe organophosphate poisoning: experience of a northwest Indian hospital

OBJECTIVE

The aim of the study was to find whether continuous pralidoxime (2-PAM) infusion along with aggressive atropinisation improves the outcome in patients with severe organophosphate poisoning who require assisted ventilation.

METHODS

Sixteen patients admitted to the respiratory intensive care unit (RICU) with severe organophosphate poisoning and requiring assisted ventilation were included in the study. The compounds involved were phorate (six), dichlorvos (four), oxydimeton methyl (one), monocrotophos (one), methyl parathion (one) and in three it was unknown. After decontamination, they were given intravenous (iv) bolus atropine 5 mg at onset and then 2.5 mg every 5-10 min till atropinisation was achieved, and then maintained either by intermittent bolus doses or by continuous infusion if the required dose was large. They were also given continuous iv infusion of 2-PAM in dose of 7.5 mg/ kg body weight/h (maximum 500 mg/h) after an initial bolus dose of 2 g.

RESULTS

The mean (+/-S.D.) dose of atropine was 735.02 +/- 742.98 mg (range 85-3000 mg) with maximum dose on day 1. The mean (+/-S.D) duration of 2-PAM infusion was 96.4+/-49.4 h (range 10-216 h). The mean (+/-S.D) duration of mechanical ventilation (MV) was 131.5 +/- 95.65 h (range 4-336 h). Fourteen patients could be successfully extubated and two died of bronchopneumonia and sepsis (mortality 12.5%).

CONCLUSION

Continuous 2-PAM infusion along with aggressive atropinisation after initial decontamination improved the outcome but not the duration of MV in severely intoxicated patients with organophosphate compounds who required assisted ventilation in this case series.

Ultrasound-guided transthoracic co-axial biopsy of thoracic mass lesions

PURPOSE

To compare the diagnostic yield of fine-needle aspiration biopsy (FNAB) and cutting needle biopsy in thoracic lesions.

MATERIAL AND METHODS

Thirty patients with thoracic mass lesions were subjected to ultrasound-guided co-axial FNAB and cutting needle biopsy using 0.7 mm aspirating and 1.0-mm cutting needles, respectively. The diagnostic yield of the individual modalities was compared with the combined yield.

RESULTS

A conclusive diagnosis was obtained in 76.6% (n=23) of patients by FNAB and in 66.6% (n=20) by cutting needle biopsy. The combined diagnostic yield of FNAB and cutting needle biopsy was 93.3% (n=28) with a significant statistical difference (p<0.03) as compared to cutting biopsy alone. Of the patients, 23.2% (n=7) had benign and 76.6% (n=23) malignant aetiologies. The diagnostic yield of FNAB versus cutting needle biopsy in benign lesions was 57.1% (n=4) and 100% (n=7), respectively. The diagnostic yield of FNAB versus cutting needle biopsy in malignant lesions was 82.6% (n=19) and 56.5%, (n=13). Two patients remained undiagnosed by either modality. There were no complications.

CONCLUSION

FNAB and cutting needle biopsy are complementary to each other and attempts should be made to obtain small tissue cores in addition to routine cytologic specimens in diagnosing thoracic lesions, especially in benign pathologies. US provides a safe guidance modality for lesions abutting the chest wall.

Reducing the number of daily measurements results in poor estimation of diurnal variability of peak expiratory flow in healthy individuals

AIM

To determine the effect of reducing number of daily measurements on estimation of diurnal variability (DV) of peak expiratory flow (PEF).

SUBJECTS AND METHODS

PEF was recorded five times daily for three days in 152 healthy adults. Amplitude percent mean (A%M) and standard deviation percent mean (SD%M) were calculated on third day from five, four, three and two daily readings. Proportion of variability explained by partial schedules was calculated and limits of agreement derived to assess if these methods could be used interchangeably.

RESULTS

Four, three and two measurements explained 90-95%, 70-82% and 55% DV respectively using A%M. All schedules of partial measurement using SD%M explained >90% DV. Limits of agreement for A%M and SD%M widened as number of measurements were reduced.

CONCLUSIONS

DV obtained by fewer daily measurements agrees poorly with results obtained from five measurements. SD%M is a better alternative if DV is assessed from fewer readings.

Analysis of static pulmonary mechanics helps to identify functional defects in survivors of acute respiratory distress syndrome

OBJECTIVE

To assess the utility of static lung pressure-volume measurements in identifying and categorizing pulmonary function test defects in survivors of acute respiratory distress syndrome (ARDS).

DESIGN

Cross-sectional.

SETTING

Pulmonary function laboratory at a tertiary referral hospital in northern India.

PATIENTS

Six survivors of ARDS reporting for their first follow-up visit after discharge.

MEASUREMENTS AND MAIN RESULTS

Spirometry and whole body plethysmography were performed to evaluate lung volumes and to collect static lung pressure-volume data; the latter were subjected to monoexponential analysis. Three patients had a restrictive ventilatory defect as evidenced by diminished vital capacity and total lung capacity, but only one had reduced static lung compliance. The other two patients had reduced recoil pressure at total lung capacity, suggestive of respiratory muscle weakness. Two other patients with normal lung volumes had reduced static lung compliance. Exponential analysis of pressure-volume data in the three patients with reduced static lung compliance was consistent with reduced distensibility and loss of lung units in one patient each. Additionally, two patients had high values for shape constant of the exponential curve, indicative of air space distention.

CONCLUSIONS

Detailed analysis of static pressure-volume data can identify pulmonary function abnormality and categorize the dominant mechanism responsible for restrictive ventilatory defects in survivors of ARDS, even in patients with normal lung volumes. In addition to lung fibrosis, neuromuscular weakness also contributes to decline in pulmonary function.

The spectrum of respiratory mycoses in a referral hospital in north-western India

There has been an increasing recognition of respiratory mycoses in this country in the recent past. Candidiasis, aspergillosis and cryptococcosis have been reported from different centres. Occasional cases of histoplasmosis and sporotrichosis have also been reported. Infections with Pneumocystis carinii, which is now classified as a fungus, are being frequently diagnosed, especially in the immuno-compromised patients such as those on prolonged immunosuppressive therapy or with HIV infection. Although the clinical picture of respiratory mycoses resembles that of any other infection, the presentation in several cases is atypical and the diagnosis is delayed. In a review of our patients of respiratory fungal infections seen in the last few years, we found several interesting examples. We report here the general clinical spectrum of respiratory mycoses and some interesting cases seen at our Centre.

Sarcoidosis in developing countries

Sarcoidosis is seen in different parts of India and other developing countries with almost similar frequency as in the West. It was largely due to lack of awareness and non-availability of investigations for diagnosis that the disease was reported to be rare in the past. A combination of clinical, radiologic, and histologic criteria are used to diagnose sarcoidosis. A confident exclusion of other causes of granuloma formation, especially tuberculosis, is required. Absence of mycobacteria and of caseation in the histologic specimens and presence of skin anergy to tuberculin help make a diagnosis. Transbronchial lung biopsy obtained with the help of fiberoptic bronchoscopy is positive in about 80% of patients. Corticosteroids are used to treat patients with symptoms and those showing active organ involvement. Aggressive treatment is required for patients with acute and severe pulmonary, cardiac, ocular, or neurologic involvements.

Statistical estimation of height from arm span in north Indian subjects

We measured height and arm span of 400 males and 231 female subjects between 16-83 years of age. Arm span exceeded height in 82.6% subjects. Mean height to arm span ratio was 0.9711 and 0.9816 in males and females respectively, and was not significantly correlated with age. Linear regression equations were generated for both sexes for prediction of height from arm span and age. The use of height to arm span ratio was found to be a less suitable method than the use of regression equations in estimating height from arm span.

Radioisotope bone scanning in pulmonary alveolar microlithiasis

A 30-year-old woman was examined for a history of exertional breathlessness, swelling of her feet, and a mild dry cough of 4 to 5 months' duration. Her symptoms developed during the last month of her pregnancy, with gradually increasing dyspnea, swelling of the feet, and reduced urinary output. There was no history of expectoration, hemoptysis, chest pain, or tuberculosis. General physical examination showed no evidence of clubbing of the nails or lymphadenopathy. Chest auscultation revealed a few end-inspiratory crepitations at both lung bases. Bronchial alveolar lavage showed calcium particles, whereas results of the transbronchial lung biopsy were consistent with alveolar microlithiasis.

Study of the prevalence of asthma in adults in North India using a standardized field questionnaire

Prevalence of asthma was calculated using a Hindi adaptation of the International Union Against Tuberculosis and Lung Disease (IUATLD)-1984 questionnaire. The questionnaire was administered to patients with and without asthma to select specific items to define asthma. Questionnaire validity was tested against physician-diagnosed asthma in 753 individuals in the field, with sensitivity and specificity of 63.1% and 98.8%, respectively. The field prevalence study was conducted among 958 men and 1158 women. True population prevalence, calculated from the observed prevalence using specificity and sensitivity of the questionnaire, was 3.94% in urban men, 3.99% in rural men, and 1.27% in both urban and rural women.

Impact of lead exposure on pituitary-thyroid axis in humans

Thyroid function tests (serum levels of thyroxine-T4, triiodothyronine-T3 and thyroid stimulating hormone-TSH) were performed in fifty-eight men (mean age: 31.7 +/- 10.6 years; mean duration of lead exposure: 156.9 +/- 122.7 months). These subjects were exposed to lead either as petrol pump workers or automobile mechanics. The mean whole blood lead (Pb-B) levels were 2.49 +/- 0.45 micromole/l (51.90 +/- 9.40 microg/dl) in the lead exposed workers and were approximately 5 times higher than in the control (n = 35) subjects. No significant alteration was seen in their mean T3 and T4 levels as compared with the controls. Interestingly, T3 was significantly lower with the longer (210 months) exposure time in comparison with the group having shorter (29 months) exposure duration. The mean TSH levels were significantly (p < 0.01) higher in workers exposed in comparison with the control group. This rise in TSH was independent of exposure time, but it was definitely associated with the Pb-B levels. The increase being more pronounced with mean Pb-B levels of 2.66 +/- 0.2 micromole/l (55.4 +/- 4.25 microg/dl) when compared with the group having mean levels of 1.51 +/- 0.30 micromole/l (31.5 +/- 6.20 microg/dl). The rise is TSH associated with Pb-B levels was only statistical valid, however, the levels fall within the normal laboratory range. We thus conclude that the Pb-B levels of > or = 2.4 micromole/l (50 microg/dl) could enhance the pituitary release of TSH without having any significant alterations in the circulating levels of T3 and T4.

Assessing severity of asthma: spirometric correlates with visual analogue scale (VAS)

BACKGROUND

Measurements of dyspnoea in asthma are difficult. Peak expiratory flow (PEF) and forced expiratory volume in first second (FEV1) are the most widely used objective measures of bronchial obstruction in asthma. Subjective continuous scales like visual analogue scale (VAS) provide a more flexible means of grading dyspnoea as perceived by the patient.

METHODS

Utility of a VAS in assessing severity of bronchial asthma was evaluated in 195 previously diagnosed adult patients with bronchial asthma. Patients were asked to mark their severity as perceived by them on a continuous vertical VAS of 100 mm anchored at bottom with description no breathlessness' and at top by 'greatest breathlessness'. The distance measured from bottom in mm was taken as VAS score. This was correlated with FEV1 and PEF recorded immediately after the scale was marked.

RESULTS

The mean VAS score was 31.13 (+/- 28.32) mm and had a good negative correlation with FEV1 (r = 0.5255, p < 0.01) and PEF (r = 0.4609, p < 0.01). Patients were also classified into four groups of mild, moderate, severe and acute asthma, and correlation analyzed in each group separately. The correlation was more significant in subgroups of moderate and severe asthma. Educational status of subjects had no impact on this correlation.

CONCLUSION

VAS is a reasonable tool for measurement and monitoring of severity of asthma in individual patients, and may be used when more objective tests are not available.

Tracheobronchial amyloidosis: a report of two cases

We describe here two patients with tracheobronchial involvement by amyloidosis. One of them had presented with discrete tracheobronchial mass lesions simulating bronchogenic carcinoma. The other had intermittent streaky hemoptysis and was found to have diffuse tracheobronchial involvement at bronchoscopy. Both patients are doing well without any definitive therapy.

Familial aggregation of cancer in patients with bronchogenic carcinoma

History of cancer among first degree relatives was obtained in 124 patients with bronchogenic carcinoma [probands] and 248 controls, and differences in familial aggregation evaluated by calculation of odds ratio [OR] and their 95 percent confidence intervals [95% CI]. Probands were more likely than controls to have relatives with cancers [OR 1.27, 95% CI 0.49-3.10], both among smokers and nonsmokers [OR 1.31, 95% CI 0.27-6.79 and OR 1.21, 95% CI 0.12-6.16 respectively]. Sisters of probands were particularly at a higher risk [OR 8.72, 95% CI 0.85-430.08]. A genetic component, possibly independent of smoking habits, may be important in the causation of lung cancer.

Down-regulation of transforming growth factor beta receptors by androgen in ovarian cancer cells

Steroid hormones have been implicated in the etiology and/or progression of epithelial ovarian cancer. As ovarian surface epithelial cells are growth inhibited by transforming growth factor beta (TGF-beta), we tested whether steroid hormones could regulate the expression of TGF-beta1 or its receptors in ovarian cancer cells, as assessed by quantitative reverse transcription-PCR. Treatment of ovarian cancer HEY cells with 500 nM 5alpha-dihydrotestosterone (DHT), but not estradiol-17beta or progesterone, for 60 h down-regulated the expression of mRNA for TGF-beta receptors I and II (TbetaR-I and TbetaR-II), betaglycan, and endoglin but had no effect on TGF-beta1 mRNA levels. Androgen receptor (AR) mRNA expression in HEY cells was compared to other ovarian cancer cell lines. OVCAR-3 cells expressed AR mRNA levels similar to that of androgen-responsive LNCaP prostate cancer cells, whereas SKOV-3 and HEY cells expressed only 3 and 0.01%, respectively. Western blot analysis and saturation binding assays confirmed the expression of AR protein in these three cell lines, but at the limit of detection in SKOV-3 and HEY cells. Treatment of SKOV-3 and HEY cells for 24 h with 1-50 nM DHT resulted in a dose-dependent down-regulation of TbetaR-II mRNA. The AR antagonist hydroxyflutamide did not reverse the effect of DHT on SKOV-3 cells but by itself down-regulated TbetaR-II mRNA. This apparent androgen-mimetic action of hydroxyflutamide and the ability of SKOV-3 and HEY cells to respond to DHT may be due to their expression of AR-associating protein 70, an AR co-activator reported to amplify AR transactivation and to result in agonist activity of AR antagonists. DHT was able to reverse TGF-beta1 growth-inhibitory action in SKOV-3 cells and in a primary culture of ovarian cancer cells derived from ascites. Thus, androgens may promote ovarian cancer progression in part by decreasing TGF-beta receptor levels, thereby allowing ovarian cancer cells to escape TGF-beta1 growth inhibition.

Diurnal variation in peak expiratory flow in healthy young adults

Diurnal variability in peak expiratory flow (PEF) was studied for three days in 152 healthy volunteers aged 20-40 years, and expressed as amplitude percent mean (A%M) and standard deviation percent mean (SD%M). The commonest pattern (74.6%) observed was that of a nadir at waking in morning, a progressive rise upto late afternoon and a plateau or a small decrease at bedtime. Mean diurnal variation in PEF on the third day was 7.23 +/- 3.48 (A%M) and 2.98 +/- 1.31 (SD%M). Both the diurnal variation and the calculated upper limits of normality were found to be lower than those reported previously for Western subjects. This knowledge of diurnal variation is important for any meaningful interpretation of PEF recordings used to monitor patients with asthma.

Acute respiratory distress syndrome complicating typhoid fever

We report a case of a young female patient with typhoid fever whose clinical course was complicated by hypotension, thrombocytopenia, encephalopathy and acute respiratory distress syndrome (ARDS). She recovered with prompt mechanical ventilatory support. ARDS in typhoid fever has generally proved to be fatal in reported cases.

Treatment issues in interstitial lung disease in tropical countries

Management of interstitial lung disease, especially idiopathic pulmonary fibrosis, is both difficult and unsatisfactory. In many patients, only supportive therapy can be instituted. Attempts have been made to use anti-inflammatory therapy to reverse inflammation, provide symptomatic relief, stop disease progression, and prolong survival; the results of such treatment have varied from no improvement to significant prolongation of survival. Corticosteroids are the most frequently used anti-inflammatory agents. Cytotoxic drugs, such as oral azathioprine or intermittent intravenous cyclophosphamide, have also been shown to be effective both alone and in combination with low-dose oral corticosteroids. Of the other antifibrotic drugs that have been used, colchicine seems to provide some benefit. It is especially useful in aged persons and those with corticosteroid-induced problems or concomitant illnesses that are likely to be worsened by steroids. Anti-inflammatory therapy is costly to administer and monitor, particularly in the developing world. It is therefore important to consider these issues before instituting treatment. Younger patients and patients with less-severe disease of recent onset are most likely to respond to treatment. Similarly, patients with lymphocytic alveolitis or desquamative interstitial pneumonia respond better. Despite the use of newer strategies for treatment, the overall prognosis for patients with interstitial lung disease has not really changed, and the median population survival remains almost the same as it was about 30 years ago.

Bronchial hyper-responsiveness of women with asthma exposed to environmental tobacco smoke

Effect of chronic environmental tobacco smoke (ETS) exposure on bronchial responsiveness (BR) was assessed by the measurement of BR in stable, nonsmoker asthmatic women and comparison of the PD20 in the exposed and non exposed groups was also studied. Nonspecific bronchoprovocation test was performed by histamine inhalational challenge. Of fifty patients included in the study, 23 (46%) had history of ETS exposure of 1.22 (+/- 0.61) hours per day for an average of 13.07 (+/- 6.1) years. The PD20 was significantly lower in the ETS exposed group (p < 0.05). When the subjects were compared, based on their cumulative exposure expressed by an exposure index (El = duration of exposure in years multiplied by average number of hours per day), there was a statistically significant difference in PD20 of those with El of less than those with El of more than 15. It is concluded that BR is greater, and reflects the higher morbidity in the ETS exposed patients of asthma.

Physiological deadspace during normocapnic ventilation under anaesthesia

Respiratory physiological deadspace (VDphys) during normocapnic ventilation under anaesthesia was studied in 253 patients scheduled for elective non-thoracic surgery. Subjects were ventilated with SERVO 900B ventilator using CO2 analyser 930 (Siemens-Elema Sweden) to adjust minute volume sufficient to maintain end-tidal carbon dioxide fraction (FECO2) around 5.5kPa with normocapnic confirmation using arterial blood gas analysis. VDphys was calculated using Enghoff's modification of Bohr's equation. VDphys and deadspace to tidal volume ratios (VD/VT) in male patients were 142.6 +/- 28.4 ml and 0.37 +/- 0.068 respectively and were significantly higher than that in females (119.4 +/- 35.6 ml and 0.36 +/- 0.067). Males had significantly higher VDphys/mass (2.5 +/- 0.68 ml.kg) compared with females (2.2 +/- 0.54 ml/kg, P < 0.001) but significantly lower body mass index (BMI) (20.67 +/- 3.2 in males and 22.47 +/- 4.1 in females, P < 0.001). VDphys showed positive correlation with weight, height and body surface area (BSA) but VDphys/kg showed negative correlation with BMI. Multiple regression analysis produced a best fit equation for VDphys = 9.7 + 64.3 x BSA + 13.51S where S = 1 for females and 2 for males.

Diagnosis of tuberculous pleural effusion

Tuberculosis is a common cause of pleural effusion in India. Diagnosis can be made in a majority of patients from the clinical features, pleural fluid examination (including cytology, biochemistry and bacteriology), and pleural biopsy. Adenosine deaminase estimation in pleural fluid is occasionally useful. Newer diagnostic techniques include lysozyme or interferon gamma estimation, immunodiagnostic methods and polymerase chain reaction. Although promising, they still need to be studied further before their routine use can be recommended.

Passive smoking and lung cancer in Chandigarh, India

The aim of this study is to assess the relationship between exposure to environmental tobacco smoke (ETS) and lung cancer in non-smokers, a case-control study among lifetime non-smokers was conducted in Chandigarh, India. Cases consisted of 58 non-smoking histologically confirmed lung cancer patients; two controls for each case were selected, one among other patients admitted to the wards and one among the visitors to hospital patients. Subjects were asked about ETS exposure from different tobacco products in childhood and in adulthood at home, at the work place and in vehicles. Multivariate logistic regression analysis was used to assess the effects of the ETS exposure variables on lung cancer. Exposure to ETS during childhood was strongly associated with lung cancer (odds ratio (OR) = 3.9; 95% confidence interval (CI) = 1.9-8.2), the effect mostly arising from exposure to cigarettes smoke. The excess risk was observed with either a smoking father or mother. An increasing risk was found with increasing number of smokers and duration of exposure. Restricting the analysis to women produced higher estimates of the risk. No increased risk was found with exposure to a smoking spouse, except for those exposed only to cigarette smoke (OR = 5.1; 95% CI = 1.5-17). A weak association was seen between lung cancer and ETS exposure at the workplace, which increased with the number of years of exposure. Exposure in vehicles also was detected as a risk factor for lung cancer in non-smokers. This study suggests that ETS exposure may be a strong risk factor for lung cancer also in India, a country with low prevalence of smoking and, therefore, low rates of lung cancer. Other studies need to be conducted in similar settings to confirm the role played by ETS exposure early in life in the causation of lung cancer.

Interpreting spirometric data: impact of substitution of arm span for standing height in adults from North India

STUDY OBJECTIVE

To evaluate if direct substitution of arm span for height during interpretation of spirometry data leads to any significant statistical or clinical differences in Indian adults, and to compare this method with the use of height estimated indirectly from arm span.

DESIGN

Cross-sectional.

SETTING

Respiratory laboratory of a tertiary referral hospital in North India.

PARTICIPANTS

Two hundred twenty-eight subjects referred for spirometry.

MEASUREMENTS AND RESULTS

Standing height and arm span were measured for all subjects. Spirometry measurements included FVC, FEV1, FEV1/FVC, peak expiratory flow, and maximal midexpiratory flow. Predicted values for each parameter were calculated separately for height, arm span, and height estimated from fixed height:arm span ratio. Results were classified into normal, obstructive, and restrictive defects for each height, arm span, and estimated height measurement, and any abnormality was categorized as mild, moderate, or severe. Arm span exceeded height in 182 (79.82%) subjects. Thirty-seven (16.2%) and 32 (14.0%) results were classified or categorized incorrectly when arm span and estimated height were substituted respectively, for actual height, with a kappa estimate of agreement 0.779 and 0.808, respectively; 17.4% and 11.0% normal results were classified, respectively, as restrictive defects using arm span and estimated height. Limits of agreement, which were almost equally wide for both sets of data, were more than the permissible intraindividual variability for FVC and FEV1.

CONCLUSIONS

The substitution of arm span for height introduces statistically significant changes in spirometry results. Use of height estimated from arm span using fixed ratio also leads to misclassification of data, though less than that caused by use of arm span alone. Height estimated from arm span can be substituted for actual height in patients in whom height cannot be measured reliably. Where racial/ethnic norms for height and arm span correlation are not available, arm span is a reasonable surrogate for standing height.

Determination of ventilatory minute volumes for normocapnic ventilation under anaesthesia in healthy adults

BACKGROUND

Mechanical ventilation under anaesthesia needs to be controlled to maintain normal oxygen and carbon dioxide tensions in the blood and to economize on fresh gas flows. Various ventilation nomograms such as Radford's nomogram and Nunn's CO2 predictor are based on data from studies, some of which do not mimic the conditions which prevail under anaesthesia. We, therefore, planned a study to formulate nomograms for normocapnic ventilation for anaesthetized adult subjects.

METHODS

Two hundred and fifty-three patients with normal pulmonary function tests, scheduled for elective non-thoracic surgery were studied. Subjects were ventilated with a Siemens Servo 900 B ventilator using CO2 analyser 930 (Siemens-Elema Sweden) to adjust the minute volume sufficient to maintain end-tidal carbon dioxide fraction (FE,CO2) at around 5.5 normocapnia (PaCO2 5.06-5.6 kPa). This was confirmed with arterial blood gas analysis.

RESULTS

The mean (SD) ventilation required for male patients was 6.123 (0.91) L [105 (13.1) ml/kg]. This was significantly higher than the requirement for female patients [5.262 (0.82) L; 98.7 (13.3) ml/kg]. The minute volume requirements showed a significant correlation with weight (W), height (H), body surface area, body mass index and other combinations of weight and height such as W x H, W/H, W2, W3 and H/W1/3. Nomograms were constructed for different weights and heights of males and females using multiple regression analysis. These minute volumes were found to be significantly higher than those calculated according to Radford's nomogram as well as Nunn's CO2 predictor and significantly lower than the Adelaide ventilation guide.

CONCLUSION

The differences obtained in our nomograms are probably because the earlier ones were based on minute carbon dioxide production and physiological dead space data obtained from widely differing studies, some of which did not resemble conditions prevailing under anaesthesia. None of these used strict inclusion criteria such as pulmonary function tests. These may also be due to a difference in body structure between the subjects studied. Therefore, minute volume requirements calculated based on available western nomograms should not be applied to Indian subjects for normocapnic ventilation under anaesthesia.

Acute respiratory distress syndrome following nitrogen dioxide exposure

A young laborer was accidentally exposed to toxic nitrogen dioxide fumes following an accidental explosion at work place. He developed acute respiratory distress within few hours of exposure and manifested with severe hypoxemia and permeability edema. Assistance with mechanical ventilation and corticosteroid therapy could be instituted only after 24 hours of exposure. He had shown remarkable recovery and could be weaned off after seven days. At three weeks after discharge, his lung function tests were normal.

Algorithm for diagnosing pulmonary fibrosis in tropical countries

An algorithm for diagnosis of pulmonary fibrosis in the tropical countries has been developed on the basis of the common causes of fibrosis, and the availability and feasibility of different diagnostic techniques in those countries. First, it is important to exclude common diseases such as the atypical or occult forms of bronchiectasis, pulmonary tuberculosis, and chronic bronchitis, which often overshadow interstitial pulmonary fibrosis. A good history and physical examination supplemented with chest radiography and simple lung function tests are generally enough to narrow down the list of causes of diffuse lung disease to interstitial pulmonary fibrosis. The real difficulty lies in identifying the idiopathic or "lone" forms from the secondary forms of pulmonary fibrosis. High-resolution CT is helpful in a large number of patients. Transbronchial lung biopsy is performed in a select population of patients. Open surgical or thoracoscopy guided biopsy is the gold standard, but is rarely required.

Response to steroid therapy in patients of idiopathic pulmonary fibrosis: a retrospective analysis

Fifty four patients of idiopathic pulmonary fibrosis were evaluated retrospectively to see the effect of prednisolone therapy on the course of the disease. The diagnosis was established based on clinical history, physical findings, radiology, HRCT, spirometry and transbronchial biopsy whenever possible. Each patient received prednisolone 1 mg/kg/day for 6 weeks which was then tapered gradually till a maintenance dose was achieved. Six patients (11.1%) died within 3 months (3 within 1 month) of presentation because of rapid progression of the disease and inspite of addition of intravenous methyl prednisolone. Improvement in symptomatology, particularly cough and dyspnoea, were quite variable. Twenty six (48.1%) reported subjective improvement by 20-80% of the initial symptoms. However, in most cases this improvement was for the initial 3-6 months of therapy. Subsequently either they deteriorated or remained stable. There was no clinical improvement in the remaining 20 patients (improvement in symptoms by 0 to less than 20%). There was no radiological improvement in any case. FVC improved at 3 months only after treatment compared to the baseline values (p < 0.01). However, subsequently there was no significant improvement in the lung function. Of the 37 cases whose initial FVC value could be obtained, 8 patients (21.6%) showed an improvement by more than 20% of their baseline values during their follow up period. Of these, 4 had the improvement by 3 months; 3 by 6 months; and one showed improvement at 1 year and 6 months. Five patients (13.5%) had a decrease in FVC by 10% or more during their follow up. One patient developed sputum positive pulmonary tuberculosis nine months after steroid therapy.

Exposure to Parthenium hysterophorous pollen extract leads to bronchospasm in stable patients of bronchial asthma

Role of Parthenium hysterophorous as an allergen evoking bronchial hyper-responsiveness was assessed in twenty five adult patients with stable asthma and ten healthy controls. Assessment was made with the help of skin prick and bronchial provocation tests (BPT) using a commercially available Pathenium extract. Eleven patients (44%) of the study group had a positive skin reaction and 4 (16%) showed a significant fall in FEV1 and PEFR (p < 0.05) on bronchial provocation. In the control group only one patient (10%) had a positive skin test while there was none with a positive bronchial challenge. There was a significant fall in the mean values of FEV1 and PEFR over base line after the BPT in patients of asthma than controls. It is concluded that a significant proportion of bronchial asthma patients are sensitized to Parthenium hysterophorous and it may act as a cofactor in seasonal exacerbation of their symptoms.

Silent gastroesophageal reflux in patients with bronchial asthma

Gastroesophageal reflux (GER) is a common occurrence in patients with asthma. We performed a prospective study to detect GER in patients with asthma using pH monitoring. Twenty consecutive patients (mean age 48 +/- 14 yr, range 23-70; 13 men) with asthma of unexplained etiology were evaluated. Esophageal and gastric pH were studied both while introducing and pulling out pH probe. Upper GI endoscopy was done in all the patients before doing pH monitoring. Esophageal pH was recorded at 25 cm, 30 cm and 35 cm from the incisors. Mean esophageal pH values while introducing pH probe were 2.9 +/- 1.08 (0-5.1), 2.5 +/- 1.2 (0-5) and 1.6 +/- 1.5 (0-4.6) at 25 cm, 30 cm and 35 cm from incisors respectively. The gastric pH was 0.5 +/- 0.4 (0-2). While pulling out pH probe, pH values were 1.5 +/- 1.4 (0-4.7), 2.4 +/- 1.5 (0-5.1) and 2.9 +/- 1.4 (0-5.4) at 35 cm, 30 cm, and 25 cm from incisors respectively. Of 20 patients, 19 had pH of 4 or lower at 25 cm, 30 cm and 35 cm from incisors. The mean pH value was lower at 35 cm than at 30 cm and 25 cm (1.6 +/- 1.5 vs 2.5 +/- 1.2 and 2.9 +/- 1.08, p < 0.04). In conclusion majority of adults with asthma have silent GER as detected on pH monitoring.