Carbon monoxide-diffusing capacity in intravenous drug abusers: the effect of cigarette smoking and HIV infection.

A reduction in the Dco has been frequently found in intravenous drug addicts (IVDAs) and in subjects with HIV infection. Since also cigarette smoking decreases Dco, we studied a group of street IVDAs, who did not show respiratory symptoms and/or infiltrates on chest x-ray film. Sixty-two patients were presently smoking, 2 had never smoked. Twenty-seven were HIV-negative and 37 HIV-positive. Mean values for Dco (percent of predicted values) were 78 +/- 16.4 in HIV-positives compared to 97.9 +/- 17.6 in HIV-negatives (p < 0.0001) using smoking specific equations and 71.8 +/- 15.4 in HIV-positives compared to 80.7 +/- 13.4 (p < 0.0001) using non-smokers equations. Dco was < 80 percent in 19 of 35 (54.3%) HIV-positive subjects and in 4 of 26 (15.4%) HIV-negative subjects (p < 0.009) using predicted values for smokers, and in 28 of 35 (80%) HIV-positive subjects and in 6 of 26 (23.1%) HIV-negative subjects (p < 0.0001) using predicted values for non-smokers. These data suggest that Dco alterations observed in HIV-positive subjects are due, in absence of respiratory symptoms and/or chest x-ray abnormalities, to an interstitial pneumopathy due to HIV or to a subclinical pulmonary disease. We conclude that the knowing of smoking in IVDAs is useful, but the knowing of seropositivity is much more important, since a marked reduction of Dco in these subjects suggests an HIV-related lymphocytic alveolitis, an opportunistic infection or a malignancy.

Effect of long-term treatment with sodium cromoglycate on non-specific bronchial hyperreactivity in non-atopic patients with chronic bronchitis.

Reduction in non-specific bronchial hyperreactivity has been reported in atopic asthmatic patients as a consequence of long-term treatment with sodium cromoglycate. As bronchial hyperreactivity is an undesirable feature in other forms of obstructive airways disease, we examined the effect of regular treatment with sodium cromoglycate (20 mg, 4 times daily, for 30 days) in a group of non-atopic bronchitic subjects who showed a significant bronchoconstrictor response to the inhalation of ultrasonically nebulised distilled water (fog challenge). After 30 days treatment with sodium cromoglycate, there was a significant reduction in response to fog challenge, compared with pretreatment values. There was a washout period of 12 h between the administration of the last dose of sodium cromoglycate and the second fog challenge. The possible mechanisms involved and the clinical significance of these findings are discussed.

[The effect of respiratory mechanics on the hematocrit. III. Study in patients with bronchopulmonary disease treated with intermittent positive pressure inhalation therapy]. / L'influenza della meccanica respiratoria sul valore ematocrito. Nota III. -- Ricerca su pazienti broncopneumopatici cronici sottoposti a ventiloterapia assistita a pressione positiva intermittente.

The Authors studied the behaviour of lung volumes and mechanics and of haematocrit after intermittent pulmonary positive pressure breathing (IPPB) in patients with chronic obstructive lung disease. An improvement of obstructive sindrome at 10'-20'-40' and a contemporary decreasing of haematocrit were observed. This statistically significant modification was regarded as an expression of a different distribution of blood in lung vessels dued to an increasing of this vascular compliance and to a decrease of alveolar inflation. The Authors postulate the realization of a better circulation in lung vessels which contributes to a lowering of haematocrit in these patients perhaps for a different VA/Ob ratio.

[Changes in the acid-base and water-electrolyte balance induced by salbutamol. "In vivo" studies in patients with chronic broncho-pulmonary disease and "in vitro" by tonometry of venous blood]. / Osservazioni delle modificazioni dell'equilibrio acido-base ed idro-elettrolitico indotte dal salbutamolo. Studio "in vivo" in pazienti broncopneumopatici cronici ed "in vitro" mediante tonometria di sangue venoso.

The Authors studied the effects of e.v. Salbutamol evaluating the acute "in vivo" variations of acid-base and hydro-electrolitic balance in 16 chronic obstructive lung patients undergoing e.v. drug administration, and also ionic variations "in vitro" of venous blood samples incubated and tonometrated with the drug. The results "in vivo" do not show variations of acid-base equilibrium (paO2, paCO2, pH, HCO3-); whereas diminution of haematocrit (Ht), rise of urinary osmolarity and variations of hydro-electrolitic balance (Na+, K+, Cl-) are demonstrated. The results "in vitro" do not show considerable variations on ionic assessment. These data, according to the other latest result, indicate the possible role of haemodilution. We think that the explanation of these phenomena could be a modification of renal water and electrolytes reabsorption, likely under the influence of antidiuretic hormone (ADH), stimulated in the hypothalamus and activated also by the beta-stimulant drug at tubular cell receptors.

[Changes in partial pressures of gases and of pH in the arterial blood of hypocapnic and hypercapnic subjects subjected to oxygen therapy]. / Modificazioni delle tensioni parziali dei gas e del pH nel sangue arterioso di soggetti ipo- ed ipercapnici sottoposti ad ossigenoterapia

The behaviour of partial tensions of respiratory gases and pH in the arterial blood was evaluated in anoxiaemic and hypercapnic (1st group) and hypo-eucapnic (IInd group) subjects undergoing oxygen therapy. The following phenomena were observed: 1) normalization in paO2 values in both groups; 2) statistically significant diminution in paCO2, especially as regards hypercapnic subjects; 3) statistically significant diminution in blood pH; 4) statistically significant diminution in bicarbonates. In the light of these findings, it is considered that other variables, such as the electrolytes, might play an important role in pH diminution during oxygen therapy and that further research should be carried out to look into the possibility.

[Changes in acid-base equilibrium of the arterial blood in hypoxemic-eucapnic subjects subjected to oxygen therapy with and without an antiphosphodiesterase drug]. / Modificazioni dell'equilibrio acido-base del sangue arterioso di soggetti ipossiemici-eucapnici sottoposti ad ossigenoterapia con e senza farmaco antifosfodiesterasico

The behaviour of the partial tensions of respiratory gases and the main parameters of acid base balance in hypoxaemic and eucapnic chronic bronchopneumopathics undergoing oxygen therapy has been assessed. The patiests were subdivided into two groups, the first consisting of subjects undergoing oxygen therapy alone, the second of subjects having oxygen and i.v. theophylline at the same time. Two subgroups were also distinguished. These consisted respectively of normochloraemic and hypochloraemic patients, the purpose being to reveal whether electrolytic changes could be attributed to the concentration of chlorine evaluated in basal conditions. The results obtained showed a disappearance of the hypoxaemic state without appreciable changes in paCO2 in all patients; in those undergoing oxygen therapy only, also observed were: 1) increase in plasmatic H+ and reduction in pH; 2) diminution in HCO3- and plasma Na+; 3) increase in plasma concentration of Cl-; 4) statistical significance of these data; 5) tendency of all values in the parameters considered to return to basal values upon suspension of oxygenation.

[Gasometric changes and acid-base equilibrium of venous blood oxygenated in vitro and incubated with or without a phosphodiesterase inhibitor]. / Osservazioni su le modificazioni gasometriche e dell'equilibrio acido-base di sangue venoso ossigenato "in vitro" ed incubato o non con antifosfodiesterasico

Changes in partial tension of the respiratory gases and in acid-base balance were studied in venous blood subjected to oxygenation, with or without incubation with theophylline. The following modifications were noted: 1) increased pO2; 2) decreased CO2 due to true wash-out caused by tonometry in oxygen; 3)decreased hydrogen ion concentration and bicarbonates following CO2 washing in both experimental models. A smaller reduction in pH and HCO3 was statistically significant in specimens treated with theophylline. This is seen as proof of the view that theophylline inhibits red cell membrane ion exchanges, such as to oppose or at any rate limit metabolic changes in acid-base balance induced by oxygenation.

[Acid-base equilibrium of the arterial blood of subjects with grave hypercapnia subjected to mechanical ventilation with the iron lung (concerning 2 cases of post-hypercapnic alkalosis)]. / Contributo alla conoscenza dell'equilibrio acido-base del sangue arterioso di soggetti con grave ipercapnia sottoposti a ventilazione meccanica con "polmone d'acciaio" (Su due casi di alcalosi post-ipercapnica)

Two cases of severe chronic respiratory insufficiency in severely acute phase with disturbances in acid base balance characterized by serious gaseous acidosis are reported. Therapy was based essentially on controlled ventilotherapy using an iron lung and considerable improvements were achieved clinically with practically total normalization of the acid base imbalance after only a few hours of treatment. In the following days, however, a picture of metabolic alkalosis established itself and this is discussed and interpreted as an expression of post-hypercapnic hypochloraemia.

[Changes in vitro of the electrolyte content and erythrocyte volume of the venous blood of patients with chronic pneumopathy subjected to tonometry in oxygen]. / Modificazioni "in vitro" del contenuto elettrolitico e del volume del globulo rosso del sangue venoso di soggetti broncopneumopatici cronici sottoposto a tonometria in ossigeno

As previously observed in vivo, statistically significant variations characterized by increase in chlorine and diminution in sodium, associated with an increase in red cell volume, have been noted in vitro in samples of venous blood taken from patients undergoing tonometry under oxygen. These variations appear to be independent of the basic concentration of chlorine and do not occur if the blood samples are incubated with theophylline at the same time. These results confirm the hypothesis of a "non respiratory" plasmatic acidifying effect of oxygen therapy inhibited by the antiphosphodiesterasic action of theophylline.

[Changes in paO2 and of acid-base equilibrium of the arterial blood of hypoxemic polyglobulic patients subjected to acute blood depletion]. / Modificazioni della paO2 e dell'equilibrio acido-base del sangue arterioso di soggetti ipossiemici poliglobulici sottoposti a deplezione ematica acuta

Partial respiratory gas tension and acid-base equilibrium patterns were examined in polyglobulic patients subjected to acute blood depletion. The increase in oxyhaemoglobin concentration and fall in haematocrit value already described were confirmed. It was also noted that: 1) pH increased significantly in all subjects; 2) urinary osmolarity increased in all subjects; 3) blood sodium and potassium concentration increased significantly in 14 patients (1st group), but fell in the 2nd group (8 subjects). It is suggested, therefore, that acute blood depletion changes renal reabsorption of the main electrolytes, i.e. increased values in cases where a fall in glomerular arteriolar pressure leads to increased renal medullary osmolarity, and decreased values where a fall in circulation leads to increased arteriolar pressure, hyperosmolarity of the medulla, and retainment of liquids as opposed to electrolytes.

[Influence of the ventilation mechanics on the hematocrit value. II. Research on patients subjected to pleural and pericardial punctures]. / L'influenza dell meccania ventilatoria sul valore dell'ematocrito. Nota II.-Ricerca sull'uomo malato sottoposto a centesi pleuriche e pericardiche

Changes in haematocrit values in rabbits subjected to pleural and pericardial puncture were studied. Highly significant decreases were noted. These are attributed to lung re-expansion with redistribution of the capillary bed, together with improved venous reflux, with predominance of the first or second phenomenon for each group. Better redistribution of the circulating blood mass results from these changes.