Predicted values of cardiopulmonary exercise testing in healthy individuals [a pilot study]

Cardiopulmonary exercise testing evaluates the ability of one's cardiovascular and respiratory system in maximal exercise. This was a descriptive cross-sectional pilot study conducted at Masih Daneshvari Hospital in order to determine predicted values of cardiopulmonary exercise testing in individuals with normal physical activity patterns. Thirty four individuals [14 women, 20 men] between 18-57 years of age were chosen using simple sampling method and evaluated with an incremental progressive cycle-ergometer test to a symptom-limited maximal tolerable work load. Subjects with a history of ischemic heart disease, pulmonary disease or neuromuscular disease were excluded from the study. Smokers were included but we made sure that all subjects had normal FEV1 and FEV1/FVC. This study aimed to compare measured values of VO[2], VCO[2], VO[2]/Kg, RER, O[2]pulse, HRR, HR, Load, Ant, BF, BR, VE, EQCO[2], and EQO[2] with previously published predicted values. We found that our obtained values for VO[2] max, HRR max and HR max were different from standard tables but such difference was not observed for other understudy variables. Multiple linear regression analysis was done for height, weight and age [due to the small number of samples, no difference was detected between males and females]. VO[2] max and load max had reverse correlation with age and direct correlation with weight and height [P<0.05] but the greatest correlation was observed for height. Due to the small number of samples and poor correlations it was not possible to do regression analysis for other variables. In the next study with a larger sample size predicted values for all variables will be calculated. If the future study also indicates a significant difference between the predicted values and the reference values, we will need standard tables made specifically for our own country, Iran

Methacoline challenge test as an evaluator of response to statins in bronchial hyperresponsiveness

3-hydroxy-3-methylglutaryl-CoA reductase inhibitors [statins], are effective serum cholesterol-lowering agents which also have anti-inflammatory properties. The objective of this study was to evaluate the effect of atorvastatin on bronchial hyperresponsiveness. Adult patients [age 14 to 65 years] with bronchial hyperresponsiveness [BHR] diagnosis based on the spirometry with methacholine challenge test were entered into the study. The study was conducted in the National Research Institute of Tuberculosis and Lung Disease. Patients were randomized to receive either atorvastatin 20 mg/day or placebo for 4 weeks. Spirometric parameters were determined at baseline and at completion of the study. Twenty two patients with the age of 32.95 +/- 10.30 years completed the trial. Changes in airway responsiveness categories [moderate to severe, mild, borderline, normal] after the intervention were not significant in atorvastatin group as in placebo group [p-value= 0.131 for atorvastatin group and p-value = 0.305 for placebo group]. Also, changes in methacholine solution number [different concentrations of methacholine] which caused at least 20% decrease in FEV1 were not significant between groups [p-value = 0.089]. Although we could not find a significant difference, the patients' fall in FEV1 in atorvastatin group was observed in higher concentrations of methacholine. Median before treatment versus after treatment in atorvastatin group was 1 versus 4 mg/mL, while those were 2 versus 1 mg/mL in placebo group. This study showed a better but not significant hyperresponsiveness control in the treatment group. The result might be presented more pronounced, if we could increase the sample size

Assessing the performance of two clinical severity scoring systems in the ICU of a tertiary respiratory disease center

The aim of this study is to compare the performance of five applied general severity scoring systems and their ability to predict mortality rate for the intensive care unit patients: Simplified Acute Physiology Score II [SAPS II], Mortality Probability Model II at admission [MPM II[0]], at 24 hours [MPM II[24]], at 48 hours [MPM II[48]] and over time [MPM II[over time]]. These scoring systems have been developed in response to an increased emphasis on the evaluation and monitoring of health care services; and also making cost-effective decisions. In this historical cohort study, all of the scoring systems were applied to 114 patients and the predicted mortality rate and the Standardized Mortality Ratio [SMR] were calculated for them. Calibration of each model and discriminative powers were evaluated by using Hosmer-Lemeshow goodness of fit test and ROC curve analysis, respectively. The predicted mortalities were not significantly deviated from the main systems [SMR for SAPS II: 0.79, MPM II[0]: 1.10, MPM II[24]: 1.32, MPM II[48]: 1.08 and MPM[Over time]: 1.02]. The Hosmer-Lemeshow statistics had the least value for MPM II[48] [C=2.922, p-value=0.939]; and the discrimination was best for MPM II[24] [AUC=0.927] followed by SAPS II [AUC=0.903], MPM II[0] [AUC=0.899], MPM II[48] [AUC=0.848] and MPM II[over time] [AUC=0.861]. All five general ICU morality predictors showed accurate standardized mortality ratio. MPM II[24] had the best discrimination, MPM II[0] had the best SMR before 24 hours and MPM[over time] had the best SMR after 24 hours. Performance of MPM II and its ease of use make it an efficient model for mortality prediction in our study

Relationship between the severity of airway obstruction and inspiratory muscles dysfunction in COPD patients

COPD is known as the main cause of morbidity and mortality in the world. Morbidity in COPD patients is mainly due to the respiratory muscle dysfunction especially diaphragm and chest wall muscles. Respiratory muscle dysfunction is mostly seen in severe and progressive stages of the disease. COPD results in increased functional residual capacity [FRC]. In severe cases of COPD, respiratory muscle dysfunction and FRC raise lead to the deterioration of hyperinflation. In our study, 30 COPD patients [28 males, 2 females] referred to Masih Daneshvari Hospital were evaluated. All cases were studied with the exact same body plethysmography equipment and the same technician. The average age, height, weight and BMI of cases were 53 +/- 11 yrs,168.86 +/- 6.33 cm, 65.44 +/- 16.78 kg and 23.56 +/- 6.32, respectively. The mean FEV1 according to the GOLD criteria was in the range of moderate to severe. Hyperinflation noted characterized by RV and reverse RV/TLC, was clearly noticed in our study [RV=225.9 +/- 82.11, RV/TLC%= 195 +/- 34.49]. Based on our study results, there was a significant correlation between FEV1, hyperinflation [RV/TLC, RV], respiratory muscle function [PImax/P1] and respiratory time cycle Ti/Ttot .It should be mentioned that there was a significant correlation between PImax and Tension Time Index as well

Assessment of wells criteria in patients with pulmonary embolism

Pulmonary embolism [PE] is one of the most important emergencies in internal medicine. Wells criteria are used to predict the presence of pulmonary embolism on the basis of clinical manifestations. The aim of this study was to assess Wells criteria in patients with pulmonary embolism. Materials and Ninety-nine patients with the diagnosis of PE underwent anticoagulant therapy during 2002-2006. Data were collected using a questionnaire and then analyzed by using SPSS software. The most common symptoms were dyspnea [70.7%] and chest pain [60.6%]. Wells criteria included "an alternative diagnosis less likely than PE" [84%], hemoptysis [34%], leg pain or swelling [30%], tachycardia [29%], recent surgery or immobilization [27%], previous deep vein thrombosis [22%] and malignancy [2%]. Eight percent, 69% and 23% of patients had Wells scores less than 2 points, 2-6 and >6 points, respectively. Among the patient group with modified Wells criteria, 36 patients [36.4%] had scores <4 points and 63 [63.6%] had scores greater than 4 points. The majority of patients with PE had Wells score of 2-6 points and those patients with Wells score less than 4 had a positive CT-angiogram

Effect of nutrition on inspiratory muscles and FEV1 in patients with emphysema

Malnutrition is an effective factor in respiratory muscles dysfunction in patients with chronic obstructive pulmonary disease [COPD]. The present study was performed to evaluate the effect of improved nutrition on inspiratory muscles in patients with advanced COPD. Total of 33 patients suffering from emphysema were studied during a 3-year period using a quasi experimental [before- after study] method. All of them had forced expiratory volume in one second [FEV1] < 30% and had received Atrovent, Salmeterol, Becotide [in maximum doses] and oxygen therapy for at least one year. Initially, FEV1 and airways resistance of patients were measured using body plethysmography .After a 35 Kcal/kg diet including 20-40% fat, 40% protein and 20% carbohydrates, these patients were followed by monthly scheduled visits. Spirometric parameters were measured again 3 and 6 months later and the results were analyzed using Freedman method. Pulmonary function tests of the under study patients at the beginning, 3 and 6 months later were as follows respectively; FEV1; 18.3%, 19.57%, 20.95%, airways resistance; 65.3%, 63.7%, 64.9% and maximal inspiratory pressure [MIP]; 2.59, 3.062 and 3.29 cmH2O. There was a significant difference in FEV1 and MIP of patients in 3 and 6 months period [P < 0.05]. Meanwhile, there was no significant difference in airways resistance of patients [P=0.08]. Improved nutrition results in increased MIP and FEV1 without changing in other indices [i.e. constant airways resistance indicates constant treatment status of the patient]. Thus, an appropriate nutritional diet including sufficient calorie with small frequent meals at least for six months can increase FEV1 by reinforcing inspiratory muscles resulting in improved pulmonary function