FACTORS INFLUENCING THE ARTERIAL OXYGEN TENSION DURING ANAESTHESIA WITH ARTIFICIAL VENTILATION

Factors influencing oxygenation of the arterial blood were studiedin 26 patients, during routine anaesthesia with artificial ventilation.The mean minute volume was 10 1./min and the arterial Pco₂ 27mm Hg. The mean oxygen consumption was 215 ml/min (STPD) andthe physiological deadspace 36 per cent of tidal volume (noallowance being made for the volume of the air passages bypassedby the endotracheal tube). At high levels of inspired oxygenconcentration, the mean alveolar-arterial Po₂ gradient was 145mm Hg, corresponding to a calculated shunt of 11 per cent. Atan alveolar Po₂, of 155 mm Hg the gradient was 52 mm Hg, correspondingto a calculated venous admixture of 9 per cent. There was noprogressive increase in venous admixture during anaesthesiain patients under the age of 43 but most of the older patientsshowed falls and their mean change was significant. Attemptswere made to reduce the venous admixture by hyperinflation ofthe lungs. This was successful in some patients, when a pressureof 40 cm H₂O was maintained for 40 seconds. Lower pressures,and the use of a sustained expiratory pressure of 5 cm H₂O werenot effective. Indices of disordered respiratory function foundin this study were not significantly different from those ina comparable study of anaesthetized patients breathing spontaneously. Present addresses: ^* Department of Anaesthesia, University ofLeeds, 24 Hyde Terrace, Leeds, 2. Present addresses: Veterans Administration Hospital, Salt LakeCity, Utah, U.S.A. Present addresses: University of Natal, Durban, South Africa.     

Treatment of Goodpasture syndrome with cyclophosphamide, prednisone and plasma exchange transfusions.

Repeated plasm exchanges were performed in a 44-year-old man with Goodpasture syndrome, also treated with cyclophosphamide and prednisone. Improvement was observed within 3 weeks of starting the protocol, and by the 76th week, endogenous creatinine clearance had increased from 30 to 56 ml/min/1.73 M2 and serum albumin from 2.7 to 3.7 g/dl. Prior treatment with immunosuppressive drugs had not significantly influenced circulating antibody levels. But sustained suppression of antibody was achieved after the plasma exchanges were begun, suggesting that physical removal of circulating antibody combined with antiproliferative drug treatment may be a useful way to control undesirable humoral immune responses.     

Schwefelkohlenstoff-Einwirkungen auf die rhino-otologischen Funktionen der BeschÄftigten in der Kunstfaser-Industrie

Zusammenfassung Im Rahmen von Reihenuntersuchungen verschiedener Altersgruppen CS₂-Exponierter in der Kunstfaser-Industrie werden unter Berücksichtigung dort herrschender LautstÄrken die rhino-otologischen Funktionen untersucht. Bei den Exponierten zeigten sich vermehrt trockene NasenschleimhÄute sowie ein olfaktorisches Funktionsdefizit. Bei den otologischen Funktionen fanden sich Reduzierung der Tonschwellen in den hohen Frequenzen, überwiegen des calorisch bedingten Nystagmus bei der Warmspülung und vermehrte pathologische Nystagmusformen. Die Vestibularisbefunde gehen anderen klinischen Erscheinungen voraus und sind als Frühsymptom einer Intoxikation zu werten. Die Vestibularisprüfung wird in den FÄllen empfohlen, wo die Anwendung des EEG auf Schwierigkeiten stö\t. Die Auswirkungen im Bereich der Cochlea führen weder durch CS₂ allein noch in Kombination mit den in der Kunstfaser-Industrie herrschenden LautstÄrken zu einer EinschrÄnkung der akustischen Information.

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CS₂-effects upon olfactory and auditory functions of employees in the synthetic-fiber industry

Summary Examinations of nasal and auditory functions were performed on a number of different age groups of people exposed to CS₂ in the synthetic-fiber industry. In people thus exposed, dry nasal mucous membranes as well as a deficit in olfactory functioning was evident. The auditory examinations showed a reduction of thresholds in the high frequences, a predominance of calorically caused nystagmus, and an increase in pathological forms of nystagmus.The vestibular symptoms precede other clinical evidence and are to be regarded as early symptoms of an intoxication. These vestibular examinations are recommended in all cases where it is difficult to use the EEG. It seems that neither exposure to CS₂ alone nor such exposure in combination with the prevailing noise levels in the synthetic-fiber industry led to a reduction of the acoustic information in the cochlea.

     

屏气相位对比MRI评价正常人冠状动脉血流储备

目的　研究屏气相位对比ＭＲ（ＰＣＭＲ） 技术测定正常人冠状动脉血流储备（ＣＦＲ） 的可行性。方法　健康志愿者１５ 例（男１２ 例,女３ 例）。采用快速屏气Ｋ空间分段ＰＣＭＲ技术,测定冠状动脉左前降支（ＬＡＤ）静息状态和静注潘生丁负荷状态下的舒张期峰值血流速度、容积流率及ＣＦＲ。结果基础状态ＬＡＤ容积流率为（３５－４±１３－３） ｍｌ／ｍｉｎ,静注潘生丁后明显增加至（１５５－４ ±６６－８） ｍｌ／ｍｉｎ（Ｐ＜０－０１）, 平均ＣＦＲ为４－４±０－７３。基础状态ＬＡＤ峰值流速为（２２－５±３－９）ｃｍ ／ｓ, 静注潘生丁后明显增加至（６３－８±１６－７）ｃｍ／ｓ（ Ｐ＜ ０－０１）, 两者比值为２－９±０－７２ 。结论　该研究表明采用屏气ＰＣＭＲＩ流速编码技术可以定量测定正常人冠状动脉容积流率、峰值流速,从而评价ＣＦＲ。     

Addition of inhaled salmeterol to inhaled corticosteroids in patients with poorly controlled nocturnal asthma

The effect of adding inhaled salmeterol to inhaled corticosteroids was studied in patients with poorly controlled nocturnal asthma. In a double-blind, cross-over study, 20 patients were randomized to receive either salmeterol 50 micrograms twice daily or placebo via a Diskhaler after a 1-week run-in period. After 4 weeks of treatment, patients were subsequently crossed over to receive the other treatment for a further 4 weeks with a 2-week wash-out period in between. The response to treatment was assessed by peak expiratory flow rates (PEF) measured in the morning and evening, symptom scores of asthma, number of bronchodilators used, forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) at regular intervals. Patients' preference for the Diskhaler or metered-dose inhaler was assessed at the last visit. The results showed that morning PEF was significantly higher while on salmeterol than on placebo (296.9 +/- 70.2 vs 274.6 +/- 77.4 L/min). Evening PEF showed a trend towards a higher value while on salmeterol than on placebo (321.1 +/- 73.4 vs 288.7 +/- 79.4 L/min), but the difference was not significant. There was no statistically significant improvement in symptom scores, number of rescue bronchodilators used and FEV1 or FVC between the two treatment groups. The occurrence of side effects in terms of tremors and palpitations between treatment and placebo were similar. There were more patients who preferred Diskhaler to metered-dose inhaler (70% vs 30%). We conclude that salmeterol 50 micrograms twice daily produces significant improvement in morning PEF and is well tolerated in patients with nocturnal asthma. Diskhaler is a device which is easy to use and preferred to a metered-dose inhaler.     

Quality of medicines stored together in multi‐compartment compliance aids

Background and Objective: Dispensing medicines into compliance aids is a common practice in pharmacy contrary to manufacturers’ advice and studies have shown the appearance of light‐sensitive tablets is compromised by such storage; we previously found evidence of reduced bioavailability at elevated temperature and humidity. Our objective was to examine the physicochemical stability of two generic atenolol tablets in different compliance aids and with aspirin co‐storage at room temperature and at 40 °C/75% relative humidity. Methods: The physicochemical stability of atenolol tablets was evaluated after 28 days of storage and compared with controls by examining visual appearance, weight, disintegration, dissolution, friability and hardness to accepted standards and using a previously validated HPLC method for chemical assay. Results and Discussion: The response to storage was brand‐dependent and not straightforward. With one make of atenolol (Alpharma), storage in compliance aids even at room temperature impacted on physical stability, reducing tablet hardness, with storage in Dosett^® exerting a greater impact than storage in Medidos^® (t‐test P < 0·001). Co‐storage at elevated temperature and humidity also impacted on the appearance of non‐coated aspirin tablets (Angette?). The chemical stability of atenolol was not affected and we did not find evidence of changes to bioavailability with either make. Certainly data for one atenolol make (CP Pharmaceuticals) co‐stored with aspirin (Angette? and Nu‐Seals) in both compliance aids at room temperature provided evidence of short‐term stability. But medicines are dispensed into compliance aids in multi‐factorial ways so our study highlights not only the lack of evidence but also a realization that evidence to support real practice may not be accomplished through research. Conclusion: Reassuring practitioners of the continued stability of medicines in compliance aids under the countless condition in which they are dispensed in practice may requires a different approach involving medical device regulators and more definitive professional guidance.