Effects of inhaled furosemide on exertional dyspnea in chronic obstructive pulmonary disease

The aim of this study is to investigate the effects of inhaled furosemide on the sensation of dyspnea produced during exercise in patients with stable chronic obstructive pulmonary disease (COPD). In a double-blind, randomized, crossover study we compared the effect of inhaled furosemide on dyspneic sensation during exercise testing with that of placebo. Spirometry and incremental and constant-load exercise testing were performed after inhalation of placebo or furosemide on 2 separate days in 19 patients with moderate or severe COPD. Subjects were asked to rate their sensation of respiratory discomfort using a 100-mm visual analog scale. There was significant improvement in mean FEV1 and FVC after inhalation of furosemide (p = 0.038 and 0.005, respectively) but not after placebo. At standardized exercise time during constant-load exercise testing but not during incremental exercise, the mean dyspneic visual analog scale score was lower after inhalation of furosemide compared with placebo (33.7 +/- 25.2 vs. 42.4 +/- 24.0 mm, respectively, p = 0.014). We conclude that inhalation of furosemide alleviates the sensation of dyspnea induced by constant-load exercise testing in patients with COPD and that there is significant bronchodilation after inhalation of furosemide compared with placebo in these patients.     

Effects of furosemide and slow-release furosemide on thoracic fluid volumes

Transthoracic electrical impedance (TEI) was used to assess the relative effectiveness of a 60 mg sustained-release furosemide preparation (FR) and a 40 mg standard furosemide tablet (F), in reducing the fluid content in the thoracic cavity. A double-blind crossover study was performed, in which 12 men with a history of one or more myocardial infarctions and mild left heart failure treated with 40 mg furosemide once daily participated. The trial, lasting 28 days, was divided into two 14-day periods. Each participant received one active drug and one placebo preparation daily, the same regimen being maintained for 14 days, when the active substances were switched. TEI, body weight, serum potassium, sodium, creatinine, and urate were measured immediately prior to the start of the study, after 14 days, and at the end of the study. TEI was measured at frequencies of 1 and 100 kHz with a constant current of 100 microA, during a period of one hour following an intravenous injection of 40 mg furosemide, when the urine volumes were measured also. TEI and urine production after the furosemide injections were similar irrespective of the drug preparation. No evidence of treatment period interaction was seen. No significant differences were demonstrated in body weight and blood chemistry during the trial. These results suggest clinical equipotency of the two preparations in mild left heart failure.     

Colloid osmotic pressure in pulmonary edema clearance with furosemide

After tripling of baseline lung water (EVLW), decreasing wedge pressure (PWP) alone for two hours did not decrease EVLW. In 11 of 16 dogs, triple baseline EVLW and a decrease in plasma colloid osmotic pressure (COP) from 21.1 +/- 0.8 to 17.8 +/- 0.8 mm Hg resulted from left atrial balloon inflation at PWP of 28 to 30 mm Hg. With subsequent lowering of PWP to 10 mm Hg, intravenously administered furosemide (1 mg/kg) was given to these 11 dogs. One half hour after furosemide, shunt decreased slightly without decreasing EVLW in all 11 dogs, but by two hours, seven dogs (group 1) decreased EVLW (from 23.2 +/- 1.8 to 11.1 +/- 1.4 ml/kg) and shunt (37.4 +/- 2.0 to 12.9 +/- 2.9 percent), while four dogs (group 2) did not (EVLW: 22.3 +/- 1.4 to 22.5 +/- 0.6 ml/kg: shunt, 36.8 +/- 1.7 to 36.5 +/- 1.9 percent). Group 1 had diuresis, maintained normal blood urea nitrogen and creatinine levels, and increased COP from 17.7 +/- 0.7 to 23.6 +/- 0.5 mm Hg while group 2 was oliguric with elevated BUN and creatinine values and showed no change in COP (17.9 +/- 0.9 to 18.3 +/- 0.6 mm Hg) after furosemide. After decreasing PWP in massive pulmonary edema (triple baseline EVLW), furosemide appeared to enhance edema clearance by changes in COP with diuresis.     

Rupture of pulmonary aneurysms in association with long-standing Waterston shunts

Anastomosis of the ascending aorta to the right pulmonary artery, the so-called Waterston shunt, was undertaken as a palliative procedure for children with cyanotic congenital heart disease due to obstruction of the pulmonary outflow tract with reduced pulmonary blood flow. We present the clinicopathological correlations in two patients who underwent construction of Waterston shunts as neonates, and subsequently died of ruptured pulmonary aneurysms in adult life. Rupture should, therefore, be recognized as a late complication of this procedure, and be considered in the long-term follow-up of such patients, especially when the shunted lung is hypertensive.     

Effects of intra- and extrahepatic portal systemic shunts on insulin metabolism

To study the effects of intra- and extrahepatic portal-systemic shunts on insulin degradation, 11 patients with liver cirrhosis and 7 noncirrhotic patients with liver disease were studied with percutaneous transhepatic catheterization. Insulin levels in portal and peripheral blood were measured simultaneously for 1-2 hr after intravenous administration of glucose. The degrees of intra- and extrahepatic portal-systemic shunting were measured with this technique using 131I-macroaggregated albumin and 99mTc-macroaggregated albumin. The amount of insulin secreted and insulin degraded were assessed from the areas under blood concentration curves for portal and peripheral blood. Insulin degradation was significantly reduced in cirrhotics compared to noncirrhotics with liver disease, although there was no difference in the amount of insulin secreted between these two groups. It was also correlated significantly with the degree of intrahepatic shunting but not with the degree of extrahepatic shunting. These results suggest that intrahepatic shunting plays an important role in the reduction of insulin degradation in cirrhosis.     

Hemodynamic effects of nifedipine on pulmonary hypertension secondary to congenital heart disease with shunts

Ten patients (pts) with pulmonary hypertension (PAH) secondary to congenital heart diseases (CHD) with left to right and bidirectional shunts were studied by right heart catheterization. After getting the control hemodynamic data, pts were given nifedipine (NIF) capsule 10-20 mg sublingually and their pulmonary artery pressure (PAP), systemic blood pressure (SBP), heart rate (HR) were monitored for 60 minutes and the hemodynamic data were redetermined. The results showed that the PAP as well as SBP was decreased and the quantity index of left to right shunt (L-R QI) was also reduced by NIF in L-R shunt group (3/10). In bidirectional shunts group (7/10), 4/7 cases showed total pulmonary artery resistance index (TPRI), pulmonary artery resistance index (PARI) were decreased by 29% (P less than 0.01) and 30% (P less than 0.05) respectively without seriously increased R-L shunts. The other 3/7 pts' TPRI, PARI were increased while systemic vascular resistance index (SVRI) was lowered by 41% (P less than 0.05). The quantity index of pulmonary blood flow (Qlp) was decreased by 30 (P less than 0.05) quantity index of right to left shunt R-L QI was increased sharply by 138% (P less than 0.05) while L-R QI decreased by 76% (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Multiple pulmonary neurofibromas with hypoxemia. Occurrence due to pulmonary arteriovenous shunts within the tumors

A 62-year-old woman with multiple neurofibromas of the lung was found to have severe hypoxemia due to right-to-left shunting within the tumors. Pulmonary angiograms demonstrated that the major area of shunting was in a large tumor mass in the right lower lobe. Pathologically the neurofibromas were vascular with hyperplastic small arteries and arterioles and large dilated veins. Multiple pulmonary neurofibromas are rare; and, to our knowledge, never previously reported in association with pulmonary arteriovenous shunting.     

Assessment of operability of congenital cardiac shunts with increased pulmonary vascular resistance

Patients with large left to right shunts as a result of congenital heart disease can develop changes in pulmonary vasculature that are initially reversible. It is critical in these patients to determine whether closure of the defect would reverse some of the changes in the pulmonary vasculature. A comprehensive clinical and noninvasive evaluation often allows classification in the extremes of the spectrum, but for borderline situations, cardiac catheterization is traditionally undertaken. It is important to obtain invasive data meticulously and efficiently recognizing that the numbers only offer a snapshot and may not be representative of the usual physiologic state of the patient. There are, in addition, several caveats that need to be considered while calculating flows and resistances in these patients. Currently a holistic approach that combines clinical, noninvasive, and invasive data may be the only realistic way of making a decision regarding operability in this challenging group of patients with shunt lesions and elevated pulmonary vascular resistance. © 2008 Wiley‐Liss, Inc.     

Multiple pulmonary embolism in patients with ventriculoatrial shunts: a report on two cases

Pulmonary embolism occurred in two patients with a Spitz-Holter shunt. One patient had a massive pulmonary embolism which resulted in the development of pulmonary hypertension. The patient suffered another episode of embolism during warfarin therapy and died. Autopsy revealed a massive belateral pulmonary embolism. No thrombi were found in the venous system. The other patient had experienced symptoms that suggested recurrent pulmonary embolism before the established diagnosis. Thereafter she has constantly been treated with oral anticoagulant therapy without the recurrence of emboli.     

Effects of age on radionuclide angiographic detection and quantitation of left-to-right shunts

The usefulness of quantitative radionuclide angiography (RNA) in detecting left-to-right shunts and estimating shunt size in young children was assessed. The total population of 88 patients was divided into 2 groups: 23 patients 2 years of age and younger (mean 0.8 +/- 0.6 [+/- standard deviation] ) and 65 patients older than 2 years (mean 15 +/- 15 years). The accuracy of 2 different RNA shunt estimation techniques, the gamma variate and the Stewart-Hamilton approach, were compared with the estimations obtained at cardiac catheterization using Fick (88 patients) and indocyanine green dye-dilution techniques (20 patients). Automated data processing algorithms were used to determine the RNA estimations, thereby avoiding the effects of operator judgment and subjectivity on shunt estimation. Of the 88 patients, 16 had no shunt by Fick data (that is, estimation less than 20%) but had a left-to-right shunt demonstrated by cardiac catheterization cineangiocardiography. Nine of these patients had no shunt by RNA (that is, estimation less than 20%). For patients 2 years of age and younger, linear regression analysis of the Fick and gamma variate data provided a slope of 0.63 and a correlation coefficient of 0.82; analysis of the Fick and Stewart-Hamilton data provided a slope of 0.59 and a correlation coefficient of 0.79. For patients older than 2 years, analysis of the Fick and gamma variate data provided a slope of 0.63 and a correlation coefficient of 0.79; analysis of the Fick and Stewart-Hamilton data provided a slope of 0.64 and a correlation coefficient of 0.76.(ABSTRACT TRUNCATED AT 250 WORDS)