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Biomedical subjects

S G Spiro

Publications and source records attributed to S G Spiro.

At least 73 records · Page 4Linked to original sources

Patients at risk of chemotherapy-associated toxicity in small cell lung cancer.

During a clinical trial of duration of chemotherapy in small cell lung cancer (SCLC), 71 of 610 patients (11.6%) died in the first 3 weeks. Chemotherapy consisted of cyclophosphamide 1 g m-2 i.v. day 1, etoposide 100 mg t.d.s. orally days 1-3, vincristine 2 mg i.v. day 1. The time of death was found to be nonrandomly distributed within the first chemotherapy cycle, with a peak incidence between days 7 and 12 after chemotherapy. Patients were matched with controls who were the next cases entered into the study who did not die in the first 3 weeks. Patients dying early were more likely to have clinical hepatomegaly (P less than 0.0001), and ECOG score greater than or equal to 1 (P less than 0.00001). As a group these patients also had a higher alkaline phosphatase (P less than 0.0002), an elevated blood urea (P less than 0.00001) and a lower serum albumin (P less than 0.0001) than controls. It is probable that infection contributes to the death of these already ill patients at a time when the blood count is low. Early deaths have been noted in two other large trials using regimens including etoposide. Prophylactic antibiotics or dosage modification may prevent the early death of these high risk patients.

Adult↗

Respiratory muscle weakness in the Lambert-Eaton myasthenic syndrome.

Respiratory muscle function was assessed in six patients with the Lambert-Eaton myasthenic syndrome. Five had histologically proved small cell carcinoma of the lung; the sixth later developed metastases from an unknown primary site. Two patients had ventilatory failure, one without respiratory symptoms; another, who had emphysema, had dyspnoea and orthopnoea. The remaining three patients had no respiratory symptoms. Four patients had limb muscle weakness as judged by the maximal voluntary contraction of the quadriceps muscle (range for all subjects 32-100% predicted). Transdiaphragmatic pressure (Pdi) was measured during a maximal unoccluded sniff (Pdi: sniff), a maximal sustained inspiratory effort against a closed airway (Pdi: Pimax), and phrenic nerve stimulation (Pdi: twitch). Mild to moderate diaphragmatic weakness was present in all six patients in proportion to the degree of leg weakness (Pdi: sniff 30-64% predicted; r = 0.6; Pdi:Pimax 6-69% predicted, r = 0.8); this was associated with very low or absent Pdi:twitch during phrenic nerve stimulation. Four patients had weakness of the expiratory muscles. Improvement in muscle strength was documented in two patients after tumour chemotherapy and specific treatment with 3,4-diaminopyridine and prednisolone; one patient was still alive five years from first diagnosis. It is concluded that the respiratory muscles may be implicated in this condition more often than has previously been recognised. As the lack of mobility may cause respiratory symptoms to be minimised, the presence of respiratory muscle weakness may remain undiagnosed unless formal measurement of respiratory muscle function is made.

Autoimmune Diseases↗

Pulmonary tuberculosis in Behçet's syndrome.

Pulmonary tuberculosis has rarely been recorded in patients with Behçet's syndrome, but to date no report has convincingly demonstrated any possible association between these two diseases. We describe three cases of pulmonary tuberculosis in patients with Behcet's syndrome and discuss the possible underlying mechanisms.

Adult↗

Influence of breathing pattern on lung deposition and bronchodilator response to nebulised salbutamol in patients with stable asthma.

The influence of breathing pattern on lung deposition and bronchodilator response to nebulised salbutamol is uncertain. Three different breathing patterns were assessed in eight patients with chronic stable asthma. Salbutamol solution (2.5 mg in 4 ml) mixed with technetium-99m labelled human serum albumin was nebulised by an Acorn nebuliser at a flow rate of 6 litres a minute. Particles with a mass median aerodynamic diameter of 4.8 microns were produced for inhalation by (a) tidal breathing, (b) six tidal breaths followed by three deep breaths, and (c) six tidal breaths followed by three deep breaths with a five second breath hold after each breath. Each breathing pattern was continued for four minutes. There was no significant difference in the percentage of radioaerosol deposited in the lung or in the distribution of radioaerosol within the lung as assessed by gamma camera imaging. Changes in bronchodilator responses as measured by peak expiratory flow rate (PEF), forced expiratory volume in one second (FEV1), and forced vital capacity (FVC) 30, 45, and 60 minutes after inhalation were similar for the three studies. The mean (SEM) maximum percentage change in FEV1 was 44 (7.1), 47 (9.2), and 51 (8.4) for studies 1, 2, and 3 respectively. The percentage of nebulised solution deposited in the body was also similar for the three breathing patterns--that is, 11-13%, of which 98% entered the lung. This study shows that inhaling a nebulised aerosol by tidal breathing, the simplest method, is as effective as tidal breathing with deep breaths with or without a breath hold.

Airway Resistance↗

The effect of supplementary oral nutrition in poorly nourished patients with chronic obstructive pulmonary disease.

We carried out a prospective, randomized, controlled trial to investigate the effect of a 3-month period of supplementary oral nutrition in 14 poorly nourished outpatients with COPD. Seven patients were randomized into Group 1 who received their normal diet during Months 1 to 3, a supplemented diet during Months 4 to 6, and their original normal diet during Months 7 to 9. The other 7 patients received their normal diet for the entire 9-month study period (Group 2). Seven well-nourished patients (Group 3) matched for age and severity of air-flow obstruction served as control subjects; they received their normal diet for the 9-month study period. Measurements of nutritional status, respiratory muscle and handgrip strength, sternomastoid muscle function (including frequency/force curves, maximal relaxation rate, and a fatigability test), lung function, arterial blood gas tensions, general well-being and breathlessness scores, and 6-min walking distances were carried out monthly in all patients. At the start of the study, the poorly nourished patients had lower mean daily calorie and protein intakes than did the well-nourished patients. The poorly nourished patients had lower respiratory muscle and handgrip strength, and abnormal contractility and increased fatigability of the sternomastoid muscle compared with those in the well-nourished patients. After 3 months of supplementary oral nutrition, there was a significant improvement in the nutritional status of Group 1 patients, as evidenced by an increase in body weight, triceps skinfold thickness, and midarm muscle circumference. Respiratory muscle and handgrip strength increased in parallel with nutritional status, although there were no significant changes in lung function or arterial blood gas tensions.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Non-surgical therapy of lung cancer--a critical review by a respiratory physician.

The state of the art of radiotherapy and chemotherapy in inoperable lung cancer is described. The possible role of radical and palliative radiotherapy is also discussed. There is an extreme contrast between small cell lung cancer and non small cell lung cancer with regard to prognosis (with and without therapy) and to their sensitivity to chemotherapy. Radiotherapy with curative intent (radical dosage) is disappointing in both cell types, however as a palliative measure it is most useful in the majority of situations in all lung cancer cell types. Small cell cancer is in general extremely sensitive to chemotherapy but the responses are usually of limited duration, probably due to the development of drug resistance. Non small cell lung cancer is insensitive to chemotherapy. New trends in radiotherapy and chemotherapy are described.

Carcinoma, Non-Small-Cell Lung↗

Effect of particle size of bronchodilator aerosols on lung distribution and pulmonary function in patients with chronic asthma.

The particle size of bronchodilator aerosols may be important in determining the site of deposition in the lung and their therapeutic effect. The distribution of aerosols (labelled with technetium-99m diethylene triamine pentacetic acid) of two different particle sizes has been studied by gamma camera imaging. The particles had mass median aerodynamic diameters (geometric standard deviations) of 1.4 (1.4) and 5.5 (2.3) micron, and they were administered from a jet nebuliser to eight patients with chronic severe stable asthma. There was no significant difference in peripheral lung deposition with the two aerosols in any patient. The bronchodilator effect of the two aerosols was determined from cumulative dose-response studies. To avoid large doses that might mask possible differences in effect due to aerosol size, small, precisely determined incremental amounts of salbutamol (25-250 micrograms total lung dose) were used. The two doses were given via a nebuliser on separate occasions and the bronchodilator response was measured from FEV1, forced vital capacity, and peak expiratory flow 30 minutes after each dose. Bronchodilatation was similar with the two aerosols at each dose of salbutamol. There was therefore no difference in distribution within the lung or any difference in bronchodilator effect between an aerosol of small (1.4 micron) particle size and an aerosol of 5.5 microns in patients with severe but stable asthma.

Albuterol↗

Sternomastoid muscle function and fatigue in breathless patients with severe respiratory disease.

In patients with severe respiratory disease, the work of breathing is increased and the respiratory muscles, particularly those of inspiration, may become fatigued. Hitherto, there has been little information on the incidence of respiratory muscle fatigue in acutely breathless patients. We studied 34 patients with severe respiratory disease on admission to hospital when they were most breathless, and then, if possible, 7 to 14 days later after recovery for evidence of sternomastoid muscle fatigue or increased fatigability. Frequency/force curves, numerically expressed as the 20:50 ratio, were carried out in all patients on admission. Three of the 34 patients had evidence of low frequency fatigue (i.e., greater than 15% reduction in 20:50 ratio) in the sternomastoid muscle on admission when first studied (mean +/- SEM 20:50 ratio, 56.3 +/- 1.2%; n = 3). The mean 20:50 ratio in the remaining 31 patients on admission was 75.7 +/- 1.6% (n = 31) compared with 77.8 +/- 1.4% (n = 25) when symptomatically better (p less than 0.05). The mean 20:50 ratio on admission was also significantly lower than the mean 20:50 ratio in a group of age- and sex-matched normal control subjects (i.e., 78.5 +/- 1.4%, n = 25; p less than 0.05). Twenty-five patients were studied completely both on admission and recovery, including a fatigability test that involved the performance of 50 fatiguing head lifts with measurements of the 20:50 ratio 10 and 60 min later. Sternomastoid muscle fatigability was significantly increased on admission when the patients were most breathless, compared with recovery when they were less breathless (p less than 0.001 at both 10 and 60 min).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Diaphragm paralysis causing ventilatory failure in an adult with the rigid spine syndrome.

A syndrome consisting of a rigid spine and myopathy predominantly affecting proximal limb muscles has been previously described in children, and as with most neuromuscular disorders, the respiratory muscles appear to be affected only at an advanced stage in the disease. We describe an adult male with this syndrome who presented with ventilatory failure caused by severe respiratory muscle weakness and who demonstrated profound nocturnal arterial oxygen desaturation, particularly during rapid eye movement sleep. Treatment with negative pressure ventilation initially resulted in only modest improvements in symptoms, blood gas tensions, and nocturnal desaturation. The cause of this only partial improvement was upper airway obstruction provoked by the mode of ventilatory support used. After tracheostomy there was a dramatic and sustained improvement in symptoms and blood gas tensions and complete abolition of nocturnal arterial oxygen desaturation. This is the first report of an adult with the rigid spine syndrome presenting with ventilatory failure and cor pulmonale due to severe respiratory muscle weakness.

Adult↗

Incidence of pulmonary nodules detected by computed tomography in patients with bronchial carcinoma.

Computed tomography (CT) is more sensitive in detecting pulmonary nodules than conventional chest radiography. The incidence of pulmonary nodules on thoracic CT scans, not visible on chest radiographs, in patients with small-cell carcinoma of the bronchus (SCCB) was 27%, and in patients with non-small-cell carcinoma (non-SCCB) the incidence was 28%. Some of these nodules may be malignant. This has implications for the surgical staging of patients with lung cancer in the United Kingdom, where there is a lower incidence of benign granulomatous nodules than in the USA.

Carcinoma, Bronchogenic↗

Nocturnal angina: precipitating factors in patients with coronary artery disease and those with variant angina.

Factors precipitating nocturnal myocardial ischaemia were investigated in 10 patients with frequent daytime and nocturnal angina pectoris. Eight patients had fixed obstructive coronary artery disease or a low exercise threshold or both before the onset of ischaemia. Two patients had variant angina with normal coronary arteries and negative exercise tests. During sleep the electrocardiogram, electroencephalogram, electro-oculogram, electromyogram, chest wall movements, nasal airflow, and oxygen saturation were continuously measured. Forty two episodes of transient ST segment depression were recorded in the eight patients with coronary artery disease and 26 episodes of ST segment depression and elevation in the two patients with variant angina and normal coronary arteries. All episodes of ST segment depression in the former group of patients were preceded by an increase in heart rate as a result of arousal and lightening of sleep, bodily movements, rapid eye movement sleep, or sleep apnoea (one episode). In contrast, in the variant angina group no increase in heart rate, arousal, or apnoea preceded 23 of the 26 episodes of ST segment change. Thus increase in myocardial oxygen demand was important in precipitating nocturnal angina in patients with coronary artery disease and reduced coronary reserve. In the patients with coronary spasm these factors did not often precede the onset of nocturnal myocardial ischaemia.

Aged↗

Chylothorax: a review of 18 cases.

Eighteen patients who had developed a chylothorax during a 25 year period, 1955-80, were reviewed. The chylothoraces occurred as a complication of cardiothoracic surgery in 11 patients, of whom eight were children in the first decade of life. Five cases followed operations for coarctation of the aorta and two occurred as a complication of a Blalock shunt for Fallot's tetralogy. The chylothorax was evident within 48 hours of the operation in all but two patients. In seven cases a second operation was performed to prevent further chylous leakage and in two infants the thoracic duct was ligated. The remainder of the postsurgical chylothoraces responded to either continuous drainage or repeated aspiration and a low fat diet. There were no late sequelae of chylothorax following surgery. Spontaneous chylothorax was identified in seven patients and in five of these it was bilateral. Patients with spontaneous chylothorax were all adults and, despite treatment, had a poor prognosis. Three with malignant disease and two with pulmonary lymphangioleiomyomatosis had died within two years of the appearance of the chylothorax. Two patients with chronic idiopathic chylothoraces survived for more than two years and one of these developed a secondary fibrothorax.

Adult↗

Effect of aminophylline on fatigue of the sternomastoid muscle in man.

The effect of intravenous aminophylline on the contractility of the sternomastoid muscle was measured in the fresh state and after the induction of significant fatigue in five normal subjects. Fatigue was produced by repetitive isometric neck flexion, for two seconds every four seconds at 70% of the maximum voluntary contractile force, continued until exhaustion. Each subject performed three experiments, one to two weeks apart, in random order. In experiment 1 fatiguing exercise and recovery were completed without aminophylline; in experiment 2 intravenous aminophylline was started 30 minutes before exercise and continued throughout the 60 minute recovery period; and in experiment 3 intravenous aminophylline was started immediately after the end of exercise. Aminophylline did not influence the frequency-force relationships, relaxation rate, or maximum voluntary contractile force in the fresh muscle. After fatiguing exercise there was a relatively selective reduction in force response to stimulation frequencies of less than 30 Hz, with little alteration in forces at higher frequencies--that is, low frequency fatigue--and this effect was present for the entire one hour study period. Aminophylline given before or immediately after fatigue did not influence the recovery of either low frequency fatigue or maximum voluntary contractile force. Aminophylline at therapeutic concentrations had no significant effect on the contractility or fatiguability of the normal human sternomastoid muscle.

Adult↗

The effect of low frequency fatigue on endurance exercise in the sternomastoid muscle of normal humans.

It is not certain to what extent low frequency fatigue affects the performance of a muscle. We studied the endurance capacity of the sternomastoid muscle to undergo repetitive isometric neck flexion contractions for 2 s every 4 s at 35% of its maximal voluntary contraction force (MVC) in 5 normal subjects starting with different levels of fatigue. The endurance time, the duration the subjects were able to achieve the target force before exhaustion, was measured in each subject on 3 occasions: Study 1: in the fresh state, with a normal frequency/force curve and 20:50 ratio (ratio of force response at 20 Hz to that at 50 Hz) before the start of the endurance exercise; Study 2: with a moderately reduced 20:50 ratio before the start of endurance exercise (mean +/- SEM reduction in 20:50 ratio 11.4 +/- 0.8%); Study 3: with a substantially reduced 20:50 ratio before the start of the endurance exercise (29.2 +/- 3.7%). These reductions in 20:50 ratio were produced by the subjects performing 150 isometric neck flexion contractions at 50% of their MVC, followed by a period of rest to allow the 20:50 ratio to recover to approximately 10% of the starting value in Study 2, and to within 20 to 40% of the starting value in Study 3. Endurance exercise was then carried out.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗