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Biomedical subjects

M Lippmann

Publications and source records attributed to M Lippmann.

At least 127 records · Page 7Linked to original sources
PubMed1980

Effects of sulfuric acid aerosol inhalations.

Submicrometer H2SO4 droplets can affect pulmonary functions in humans. The lowest concentration which has been reported to produce a statistically significant effect on pulmonary mechanics is 1 mg/m3. Effects on tracheobronchial mucociliary clearance of inert particles were observed in our laboratory at much lower concentrations. For ten nonsmoking humans exposed for one hour via nasal mask to 0.1 mg/m3 of H2SO4, the mean bronchial clearance half-time was reduced by 38% (p less than 0.02) while for 1 mg/m3, it was increased by 48% (p less than 0.03). Four donkeys exposed for 1 hour daily to 0.1 mg/m3 for six months developed clearance abnormalities which persisted for at least three months after the last exposure. The patterns of mucociliary clearance responses to H2SO4 are similar to those seen previously in humans and donkeys following exposure to cigarette smoke, a known causal factor for chronic bronchitis.

Aerosols↗
PubMed1980

Experimental measurements and empirical modelling of the regional deposition of inhaled particles in humans.

Regional deposition of inhaled particles was studied experimentally in a hollow cast of the human larynx-tracheobronchial tree extending through the first six branching levels, and in twenty-six non-smoker human volunteers in vivo. Results of the hollow cast study indicated a linear dependence of particle deposition efficiency on the Stokes number for aerosols with aerodynamic diameters greater than 2 micrometers. Alveolar and total respiratory tract in vitro deposition in healthy non-smokers was minimal for particles of approximately 0.4 micrometers, and alveolar deposition for mouthpieces inhalations peaked for particles of approximately 3 micrometers. A new anatomic parameter, the bronchial deposition size (BDS), is introduced to permit the classification of various individuals and populations according to their tracheobronchial deposition efficiencies. The average BDS's were 1.20 cm for 26 healthy non-smokers, 1.02 cm for 46 cigarette smokers, 0.90 cm for 19 clinical patients being treated for obstructive lung disease and 0.60 cm for six severely disabled patients.

Aerosols↗
PubMed1980

A variable-opening mechanical larynx for use in aerosol deposition studies.

The realistic study of article deposition in model systems of the tracheobronchial tree requires that respiratory patterns and airflow profiles mimic those occurring in vivo. This paper describes a variable-opening mechanical larynx which was designed for use in deposition studies performed under cyclic flow conditions.

Aerosols↗
PubMed1980

Aerosol generation from a limited liquid medium.

A modified method for nebulization was developed for use with relatively small (20 mL) amounts of feed liquid, in this case, a suspension of radioactively tagged polystyrene (CMD = 2.87 micron, sigma g = 1.25). The method may be easily adapted for use in producing other aerosols where only this quantity of suspension material is available.

Aerosols↗
PubMed1980

Constrictive effect of pancuronium on capacitance vessels.

The effects of pancuronium 0.08 mg kg-1, metocurine 0.4 mg kg-1 and tubocurarine 0.4 mg kg-1 on vascular tone were studied in 26 patients undergoing open heart surgery during total cardiopulmonary bypass. With a fixed rate of perfusion, arterial pressure is related directly to total peripheral resistance, while the volume of blood remaining in the extracorporeal reservoir is related inversely to vascular capacity, which depends primarily on venous tone. Pancuronium increased the reservoir volume (average of 780 +/- SEM 250 ml (P less than 0.01). We conclude that under certain circumstances pancuronium constricts capacitance vessels in man.

Adult↗
PubMed1980

Deposition, retention, and clearance of inhaled particles.

The relation between the concentrations and characteristics of air contaminants in the work place and the resultant toxic doses and potential hazards after their inhalation depends greatly on their patterns of deposition and the rates and pathways for their clearance from the deposition sites. The distribution of the deposition sites of inhaled particles is strongly dependent on their aerodynamic diameters. For normal man, inhaled non-hygroscopic particles greater than or equal to 2 micrometers that deposit in the conducting airways by impaction are concentrated on to a small fraction of the surface. Cigarette smoking and bronchitis produce a proximal shift in the deposition pattern. The major factor affecting the deposition of smaller particles is their transfer from tidal to reserve air. For particles soluble in respiratory tract fluid, systemic uptake may be relatively complete for all deposition patterns, and there may be local toxic or irritant effects or both. On the other hand, slowly soluble particles depositing in the conducting airways are carried on the surface to the glottis and are swallowed within one day. Mucociliary transport rates are highly variable, both along the ciliated airways of a given individual and between individuals. The changes in clearance rates produced by drugs, cigarette smoke, and other environmental pollutants can greatly increase or decrease these rates. Particles deposited in non-ciliated airways have large surface-to-volume ratios, and clearance by dissolution can occur for materials generally considered insoluble. They may also be cleared as free particles either by passive transport along surface liquids or, after phagocytosis, by transport within alveolar macrophages. If the particles penetrate the epithelium, either bare or within macrophages, they may be sequestered within cells or enter the lymphatic circulation and be carried to pleural, hilar, and more distant lymph nodes. Non-toxic insoluble particles are cleared from the alveolar region in a series of temporal phases. The earliest, lasting several weeks, appears to include the clearance of phagocytosed particles via the bronchial tree. The terminal phases appear to be related to solubility at interstitial sites. While the mechanisms and dynamics of particle deposition and clearance are reasonably well established in broad outline, reliable quantitative data are lacking in many specific areas. More information is needed on: (1) normal behaviour, (2) the extent of the reserve capacity of the system to cope with occupational exposures, and (3) the role of compensatory changes in airway sizes and in secretory and transport rates in providing protection against occupational exposures, and in relation to the development and progression of dysfunction and disease.

Aerosols↗
PubMed1980

Cardiovascular effects of anesthetic induction with ketamine.

Anesthetic induction with ketamine has been reported to maintain or improve cardiovascular performance in severely ill patients. Using invasive cardiovascular monitoring, we studied physiologic responses to a single dose of ketamine in 12 critically ill patients. Six patient demonstrated decreases in ventricular contractility, and four had decreases in cardiac output. Mean arterial blood pressure decreased in four patients. Pulmonary venous admixture increased in four of six patients, while oxygen consumption decreased in eight of 11 patients. Thus, a single dose of ketamine produced decreases in cardiac and pulmonary performance and in peripheral oxygen transport in this group of patients. It is proposed that in severely ill patients, preoperative stress may alter the usual physiologic responses to ketamine administration, and adverse effects may predominate. Ketamine, therefore, should be used with caution for induction of anesthesia in critically ill and in acutely traumatized patients until additional studies and further information on cardiovascular responses to ketamine are available.

Anesthesia↗
PubMed1979

Hydrochlorothiazide-induced pulmonary edema. Report of a case and review of the literature.

Immediately following the initial ingestion of hydrochlorothiazide, acute pulmonary edema developed in a patient who previously used bendroflumethiazide. Unlike previously published reports, we studied the patient from immunologic and pulmonary function aspects. Using standard techniques, no significant immunological mechanisms could be demonstrated. The pulmonary function testing disclosed a widened alveolar-arterial oxygen gradient and mildly decreased diffusing capacity that cleared on serial testing. We believe that this demonstrates a rare idiosyncratic reaction that apparently is seen specifically with hydrochlorothiazide and not with other thiazide medications.

Female↗
PubMed1978

[Primary shape change of platelets in vitro (author's transl)].

Studies with interference contrast microscopy reveal that platelets undergo a typical shape change within 30--60' after venepuncture, i.e. swelling, formation of large tentacles, tiny protrusions and vesicles at the platelet surface. This "shape change" can be observed in citrated blood and PRP, heparinized blood and EDTA-blood as well. It is enhanced by low incubation temperatures (4 degrees C, 10 degrees C) and delayed at 37 degrees C as compared with room temperature. An increased number of primarily shape changed platelets is found if platelets are strongly mechanically irritated at blood sampling. The shape change is partly reversible in vitro, it is completely or almost completely reversible in vivo. Some antiaggregating agents inhibit the in vitro shape change at varying degrees (Bencyclan, SH 869 greater than ASA greater than D-Propranolol). The shape change is partly inhibited after oral or i.v. administration of ASA. A typical transformation of platelets into "spheric" forms can be observed following the addition of Bencyclan, SH 869 and D-Propranolol to PRP in vitro. The spontaneous "primary shape change" which occurs in PRP or blood after blood sampling is probably different from the secondary ADP-induced shape change. The primary shape change may influence the results of different platelet function and aggregating tests. The shape change kinetics of "healthy" subjects and patients with Hodgkin's disease differ significantly. The described method may gain more clinical interest in the future.

Aspirin↗
PubMed1978

Effects of short-term exposures to sulfuric acid and ammonium sulfate aerosols upon bronchial airway function in the donkey.

The effects of one-hour inhalation exposures to 0.3-0.6 micrometer H2SO4 and (NH4)2SO4 aerosols in the donkey were studied in terms of alterations in pulmonary flow resistance and dynamic compliance, and changes in the regional deposition and tracheobronchial mucocilliary clearance of an inert test aerosol. Short-term slowing of clearance followed certain single exposures to H2SO4 at 194-1364 microgram/m3 in three of four animals, while two of the four demonstrated a more persistent slowing of their clearance. These exposure levels produced no measurable change in resistance, compliance or regional deposition. Exposures to (NH4)SO4 up to approximately 2000 microgram/m3 had no mearurable effect upon resistance, compliance, regional deposition or mucociliary clearance.

Aerosols↗
PubMed1978

Effects of atropine and methacholine on deposition and clearance of inhaled particles in the donkey.

The influence of sympathetic and parasympathetic controls on regional particle deposition and mucociliary clearance rates was studied in the donkey in vivo. The deposition and clearance characteristics for gamma-tagged monodisperse ferric oxide microspheres were determined for inhalation tests after atropine and methacholine injections and were compared with the characteristics determined for control tests with the same animals and aerosols. Additional tests were performed in which methacholine was injected immediately after the test aerosol inhalation and 2 1/2 h before the particle inhalation. Particle deposition is shifted distally by atropine. Methacholine produces a proximal shift initially and a distal shift 2 1/2 h later. Atropine slows mucociliary transport. Methacholine produces an acceleration in bronchial clearance initially but causes a reduced rate of clearance 2 1/2 h later. Atropine slows mucociliary transport. Methacholine produces an acceleration in bronchial clearance initially but causes a reduced rate of clearance 2 1/2 h later. It also produces an initial surge in tracheal transport, which frequently leads to tracheal mucus refluxing and thereby an increase in average tracheal residence time. The drugs were used to modify the normal deposition and clearance characteristics of a particular animal so that they resembled the normal characteristics of a different animal, suggesting that much of the large intersubject variability may be attributable to different levels of autonomic tone.

Aerosols↗
PubMed1978

Butorphanol and promethazine as pre-anaesthetic medication.

An open evaluation of a combination of butorphanol (1 or 2 mg), promethazine (25 or 50 mg) and atropine (0.5 mg) in 109 adult consenting patients was carried out to determine their safety and efficacy for preanaesthetic medication. All patients were kept under direct surveillance from before intramuscular medication until they were in satisfactory condition post-operatively for discharge from the recovery room. The medications employed did not disturb the blood pressure, pulse rate or respiration rate in any of the patients. None complained of nausea or dizziness while only one was slightly excited. Sedation was rated as satisfactory in 97 per cent, and 90 per cent were free of apprehension. In addition, global evaluation of the premedication by the investigator was rated good to excellent in 99 per cent of the patients. On the basis of these observations, the combination of butorphanol with promethazine and atropine appears safe and useful for pre-anaesthetic medication.

Adolescent↗
PubMed1977

The clinical and physiological effect of whole-lung lavage in pulmonary alveolar proteinosis: a ten-year experience.

We have utilized whole-lung lavage in the successful treatment of 18 patients with pulmonary alveolar proteinosis. Our ten-year experience includes serial evaluations of patients with disabling lung dysfunction who had a total of 49 whole-lung lavages under general anesthesia. Clinical and physiological responses were documented both before and after each lavage. There were no complications or deaths. All patients were radiographically, physiologically, and symptomatically improved within hours after the procedures. Five patients required from two to four repeat lavages one to three years later. The treatment of this disorder has included a wide variety of techniques. We attribute our results to the use of a lung lavage technique that includes: (1) unilateral whole-lung lavages at two to three day intervals; (2) isotonic saline as the lavage solution; (3) use of a mechanical chest percussor during lavage; and (4) measuring the total thoracic compliance of each side in the immediate postlavage period as a guide for extubation. We conclude that whole-lung lavage is a safe, highly effective, repetitively applicable treatment for pulmonary alveolar proteinosis.

Adolescent↗