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Biomedical subjects

C Feldman

Publications and source records attributed to C Feldman.

At least 37 records · Page 2Linked to original sources
PubMed1993

Determinants of near fatality in acute severe asthma.

PURPOSE: The data extrapolated from cases of acute severe asthma that narrowly miss being fatal may prove valuable in the identification of the factors implicated in mortality. The purpose of this study was, therefore, to identify determinants of near fatality in patients with acute severe asthma. PATIENTS AND METHODS: We studied 81 patients with acute severe asthma in whom mechanical ventilation was required. Near fatality was defined as the occurrence of respiratory arrest and/or coma necessitating emergency tracheal intubation and resuscitation. In the cases that were not regarded as near fatal, tracheal intubation was performed electively because of deteriorating arterial blood gas values and/or the anticipation of exhaustion. Various continuous and categorical variables were compared in these two groups of patients. Patients with a hyperacute attack (period from onset of attack to mechanical ventilation less than 3 hours) were specifically sought and studied to determine the impact of such a course on near fatality. RESULTS: The "attack duration" (period from onset of attack to mechanical ventilation) was an important determinant of near fatality and of the subsequent clinical course. It was shorter in the group with a near-fatal episode (p < 0.03), and hyperacute attacks were uniformly near fatal. The attack duration correlated positively with the duration of the requirement for mechanical ventilation (p < 0.01). A longer attack duration was associated with an increased likelihood of the occurrence of major atelectasis (p < 0.01). There was no evidence of a relationship between near fatality and the side effects of bronchodilators as regards hypokalemia, arrhythmias, or cardiotoxicity. There was evidence of considerable under-treatment in the patient population as a whole, particularly in regard to the use of corticosteroids. CONCLUSIONS: A short attack duration is associated with an increased risk of near fatality in acute severe asthma. This is particularly evident in hyperacute attacks. Hyperacute attacks resolve rapidly once bronchodilator therapy has been instituted, suggesting that smooth muscle spasm is the predominant pathogenetic mechanism. The importance of routine anti-inflammatory therapy in mild to moderate asthma requires re-emphasis but, in addition, all patients should be provided with, and educated in the use of, bronchodilator rescue therapy, which should be available at all times. Despite current trends, the use of regular, prophylactic bronchodilator therapy in strict conjunction with anti-inflammatory agents may still be indicated. There is little evidence in the present data obtained from near-fatal cases to support the concept that cardiotoxicity related to bronchodilators contributes significantly to mortality from asthma.

Acute Disease↗
PubMed1993

A study of acute community-acquired pneumonia, including details of cardiac changes.

We prospectively studied 102 patients, aged 15-50 years, with acute community-acquired lobar pneumonia without underlying cardiorespiratory illness, admitted to Baragwanath Hospital May 1990-April 1991. Demographic, clinical, microbiological and laboratory data and negative prognostic features of these patients are described. In particular, we documented electrocardiographic changes and studied their possible relevance in patients with pneumonia. Electrocardiographic changes occurred in 32 patients (31%). The commonest changes were clockwise rotation (16%), followed by P. pulmonale (9.8%) and S1 Q3 T3 pattern (7.8%) Other changes included right axis deviation (n = 6), right bundle branch block (n = 3), ventricular extrasystoles (n = 2), atrial fibrillation (n = 1) and nodal rhythm (n = 1). These changes returned to normal in survivors after a mean of 2 days. The S1 Q3 T3 pattern was associated with cardiac enzyme leak (CK-MB fraction), hypoxia and a high Simplified Acute Physiology Score (SAPS). In addition, P. pulmonale, right axis deviation and clockwise rotation correlated with hypoxia and a high SAPS score. Clockwise rotation also correlated with serum (including cardiac fraction) enzymes leak (LDH and CK-MB fraction), and pulmonary artery pressure. The overall mortality rate was 10.8%, with no association between electrocardiographic changes and mortality. The negative prognostic factors documented were hypoxia (p < 0.0001), multilobar pulmonary consolidation (p < 0.0001), tachycardia (p = 0.0001), tachypnoea (p = 0.0002), renal dysfunction function (p = 0.0009), hypotension (systolic p < 0.02, diastolic p < 0.003), bacteraemia (p = 0.003), and serum (including cardiac fraction) enzymes leak: LDH (p < 0.02), CK (p < 0.002) and CK-MB fraction (p = 0.0002). These factors, with the exception of renal dysfunction, also correlated with the need for intensive care unit admission. Acute and reversible electrocardiographic changes are common in acute community-acquired lobar pneumonia. Electrocardiographic changes, especially those compatible with acute cor pulmonale and accompanied by cardiac enzyme (CK-MB fraction) leak, correlated with severity of illness but not with mortality.

Adolescent↗
PubMed1993

Decision making in case management of home healthcare clients.

Public health nurses face ethical decision-making dilemmas in their everyday practice, but how well are they prepared to make these decisions? This research study examined the decision-making capabilities of nurses in case management in regard to terminating and maintaining services in difficult client situations. The results showed that nurses varied in their decision-making capabilities and that their beliefs about case management were not always carried out in actual practice.

Adult↗
PubMed1993

Relation of vessel wall shear stress to atherosclerosis progression in human coronary arteries.

The purpose of this study was to determine the relation between vessel wall shear stress and the rate of atherosclerosis progression. Quantitative angiography was used to calculate the change in coronary arterial diameter over 3.0 years in patients enrolled in the Harvard Atherosclerosis Reversibility Project pilot study (n = 20 arterial segments). Vessel wall shear stress was calculated by means of a validated finite-difference model of the Navier-Stokes' equation that assumes a coronary flow rate of 8 ml/sec. The correlation between vessel wall shear stress and the change in arterial diameter at multiple points (mean, 70) along the length of the artery was then calculated for each of the 20 segments with a focal stenosis. In 15 of the 20 arterial segments there was a significant correlation (p < 0.05) between low shear stress and an increased rate of atherosclerosis progression. A Fisher's z transformation was then used to combine the correlation coefficients from all 20 segments. Low shear stress was significantly correlated (z = 0.37 +/- 0.00074, p < 0.0001) with an increased rate of atherosclerosis progression. This serial quantitative evaluation of human coronary arteries is consistent with previous data that have suggested that low shear stress promotes atherosclerosis progression. Variations in local vessel wall shear stress may explain the previously reported near-independent rate of atherosclerosis progression in multiple lesions within the same patient despite exposure to the same circulating lipoprotein values and systemic hemodynamics.

Computer Simulation↗
PubMed1993

Factors associated with airway colonisation and invasion due to Klebsiella spp.

The clinical significance of a heavy growth of Klebsiella spp. in sputum was studied in 54 patients. All but 3 patients had significant factors potentially associated with respiratory tract colonisation or invasion. Risk factors identified for colonisation of the airway and for invasive disease were similar. Patients with community-acquired Klebsiella infections were more likely to have underlying chronic respiratory diseases. Prior antibiotic use was a risk factor for nosocomial infections which occurred more commonly with antibiotic-resistant organisms. The most common diagnoses were airway colonisation, acute community-acquired chest infections, and nosocomial chest infections. Primary acute community-acquired pneumonia was uncommon. The sensitivity and specificity of the sputum Gram stain (in the setting of positive sputum cultures) in suggesting the presence of invasive disease due to Klebsiella spp. were 42% and 69% respectively.

Adolescent↗
PubMed1993

A study of immunoglobulin G subclass levels in black and white patients with various forms of obstructive lung disease.

The association of various respiratory disorders with disturbances in immunoglobulin G (IgG) subclass levels is increasingly being recognised. This was a prospective study of the IgG subclass levels in 71 patients (37 white, 34 black) with various respiratory disorders associated with obstructive airways disease. Ten white patients with adult cystic fibrosis were studied, 4 of whom were colonised with Pseudomonas aeruginosa. Alterations in individual subclass levels were seen in these patients and abnormalities noted included a decrease in IgG3 and/or an increase in IgG1 and/or IgG2 levels. Of the 17 black and 16 white patients with asthma, 2 had absent IgG4 levels associated with severe and recurrent respiratory infections, 2 had deficient IgG3 and 1 decreased IgG1 levels. Several patients had increased levels of several IgG subclasses, of which IgG1 was the most commonly affected. Both atopy and recurrent chest infections occurred most often in the latter group of patients. In the studies of 17 black and 11 white patients with bronchiectasis, all but 3 white patients were shown to have some alteration in IgG subclass levels. The commonest deficiencies were an absence of IgG4 (3 cases), and an absence of all subclasses (2 cases). One of the latter patients had an associated deficiency of total IgG and IgM, and the other demonstrated pan-hypogammaglobulinaemia. Abnormalities of IgG subclass levels appear to be commonly associated with several respiratory disorders including recurrent infections, atopy and bronchiectasis.

Adolescent↗
PubMed1992

The clinical significance of Haemophilus influenzae and H. parainfluenzae isolated from the sputum of adult patients at an urban general hospital.

Fifty-seven patients, from whose sputum Haemophilus influenzae (49 cases) or Haemophilus parainfluenzae (8 cases) was isolated during a 7-month period, were studied. In the majority of cases there were well-defined predisposing factors to respiratory tract colonisation or infection with the isolates, in particular bronchiectasis and chronic obstructive airways disease. Colonisation of the airways, bronchopneumonia in patients with underlying lung disease, acute lobar pneumonia, and postoperative chest infections were the commonest clinical diagnoses. Primary acute lobar pneumonia with these organisms alone was uncommon. All of the H. influenzae isolates were nontypeable, and there was a wide range of biotypes of both organisms. Three H. influenzae isolates produced beta-lactamase, and there was, in general, a low incidence of resistance to a wide range of antimicrobial agents on disc susceptibility testing.

Adult↗
PubMed1992

Effect of immunization with Freund's adjuvant and pneumolysin on histologic features of pneumococcal infection in the rat lung in vivo.

Immunization with Freund's adjuvant and pneumolysin and stimulation with Freund's adjuvant alone both reduced the severity of the pneumonia caused by injections of bacteria into the apical lobe bronchi of rats. Neither protocol influenced the incidence of pneumococcal bacteremia. Illness sufficiently severe to require sacrifice was delayed from 2.8 days in nonimmunized animals to 5.7 days in those immunized with Freund's adjuvant and pneumolysin (P < 0.05) and 4.5 days in those stimulated with Freund's adjuvant alone (P, not significant).

Adjuvants, Immunologic↗
PubMed1992

Does primary Streptococcus viridans pneumonia exist?

In 4 adult black patients admitted to an urban general hospital with community-acquired pneumonia, Streptococcus viridans alone was isolated from blood culture (first subculture), in the absence of any other positive microbiological finding. Sputum examination by Gram staining and culture in 3 cases was reported as negative. Echocardiography was performed in 3 cases and was normal, without evidence of endocarditis. The clinical course of illness in the 4 patients is described. The chest radiograph showed a segmental or subsegmental consolidation in all cases; this appeared 'mass-like' in 2 patients. Viridans streptococci may be a more important, if still uncommon, cause of community-acquired pneumonia than previously suspected. The organism should be considered as a possible cause of chest infection, particularly in patients with appropriately positive blood cultures and no other positive microbiological finding.

Adult↗
PubMed1992

The interaction of Streptococcus pneumoniae with intact human respiratory mucosa in vitro.

The interaction of Streptococcus pneumoniae with human ciliated upper respiratory mucosa was studied in an agar-embedded organ culture of nasal turbinate tissue, which only exposed the intact epithelial surface and its secretion. The ciliary beat frequency, measured along the edge of the organ culture, was slowed by 13% in the presence of S. pneumoniae after 16 h (p less than 0.05) compared with the control, and by 24% after 24 h (p less than 0.01). Light microscopy showed bacteria in a thickened gelatinous layer, which obscured the surface of the organ culture. Transmission and scanning electron microscopy confirmed the association of bacteria with the gelatinous layer above an epithelial surface which showed only minor changes compared to uninfected control organ cultures. Contact between bacteria and normal or damaged epithelial cells was not seen. S. pneumoniae in organ culture developed projections from their surface, which were not present after broth culture. S. pneumoniae interactions with epithelial-derived secretions, the formation of a thickened gelatinous layer, and the effects of bacterial toxins on ciliary motility, may be important during colonization of the respiratory tract.

Cilia↗
PubMed1991

Sarcoidosis in Johannesburg--a comparative study of black and white patients.

Fifty-one black and 31 white patients with histologically proven sarcoidosis were managed in the respiratory units of the Johannesburg and Hillbrow Hospitals between January 1965 and October 1987. A number of differences in the demographic, clinical and laboratory features of the disease were documented in the two groups. While none of the black patients presented with erythema nodosum, direct skin involvement was significantly more common (P less than 0.05), occurring in 59% of these patients. The mean serum angiotensin-converting enzyme level was raised in both groups, but hypercalcaemia occurred infrequently in black patients. Almost 60% of the patients received corticosteroids, and the clinical and objective response to therapy was not significantly different in the two groups. Before referral the diagnosis was often labelled tuberculosis in the black patients who had frequently received antituberculosis chemotherapy. The tuberculin skin test is helpful, since it was negative in all but 2 black patients with sarcoidosis.

Adult↗
PubMed1991

Septic shock in the Intensive Care Unit, Hillbrow Hospital, Johannesburg.

The records of all patients with septic shock admitted to an intensive care unit during a 15-month period were analysed retrospectively. The main purpose of the study was to describe the aetiology and clinical features of illness, and to determine the outcome of the patients, including those factors influencing prognosis. Thirty-five patients (46% medical, 54% surgical) fulfilling the criteria for the diagnosis of septic shock were admitted to the study. There were 21 male and 14 female patients. Most infections were community-acquired (69%). The two most common sources of infection were the respiratory tract and abdomen. All patients required inotropic blood pressure support. Most patients (94%) were mechanically ventilated and 7 required dialysis. Organisms, sometimes multiple, were isolated in 18 patients. Fifty percent of the isolates (12 of 24) were Gram-negative, 10 were Gram-positive and there were 2 associated Candida albicans bacteraemias. The overall mortality rate was 40%. There was no difference in outcome between community or hospital-acquired infections, infections with Gram-positive or Gram-negative organisms, or in patients with differing sources of sepsis. Features associated with a poorer prognosis were older age and higher bilirubin value.

Bacterial Infections↗
PubMed1991

Comparison of bacteraemic community-acquired lobar pneumonia due to Streptococcus pneumoniae and Klebsiella pneumoniae in an intensive care unit.

In a study of 41 consecutive patients with bacteraemia-associated community-acquired lobar pneumonia due to Streptococcus pneumoniae and Klebsiella pneumoniae an attempt was made to determine whether distinguishing criteria of disease due to these organisms could be identified according to demographic features and the results of initial clinical and laboratory investigations. Such information would aid in the early initiation of appropriate antimicrobial therapy. The most significant difference between the two groups of patients was the lower platelet count in the K. pneumoniae group (p less than 0.005). In addition leucopenia (p less than 0.05), higher serum albumin (p less than 0.05), and the male sex (p less than 0.05) featured with an increased frequency in patients with pulmonary infection due to K. pneumoniae. Initial antimicrobial therapy in critically ill patients with community-acquired lobar pneumonia and thrombocytopenia, particularly when associated with leucopenia and in male patients, should include agents effective against K. pneumoniae.

Adult↗
PubMed1991

Pneumolysin induces the salient histologic features of pneumococcal infection in the rat lung in vivo.

Streptococcus pneumoniae infections are common, but how they cause host tissue injury and death is incompletely understood. Immunization with pneumolysin, a thiol-activated toxin produced by the pneumococcus, partially protects animals during subsequent infection. The mechanism by which pneumolysin contributes to disease is not known. The aim of the present investigation was to determine the histologic changes induced by recombinant pneumolysin in the rat lung and to compare them with the changes induced by live organisms. Injection of either toxin (200 or 800 ng) or bacteria into the apical lobe bronchus was associated with the development of a severe lobar pneumonia restricted to the apical lobe. The changes induced by the toxin were greater at the higher concentration, and changes were most severe in those animals in which there was partial ligation of the apical lobe bronchus. The pneumonitis was less severe following injection of a modified toxin with decreased hemolytic activity, generated by site-directed mutagenesis of the cloned pneumolysin gene, indicating that this property of the toxin was important in generating pulmonary inflammation. There was still considerable pneumonitis after injection of a modified toxin with decreased capacity to activate complement.

Animals↗
PubMed1991

Metaproterenol (Alupent) metered dose inhaler in children 5-12 years of age.

This multiclinic study was performed to evaluate the safety and efficacy of metaproterenol sulfate (Alupent) metered dose inhaler in children with asthma ages 5 to 12 years. A total of 268 children completed this study according to the protocol, having received either metaproterenol or placebo for 30 consecutive days. Full spirometric testing was done pre- and postdose on Days 1 and 30 for a total duration of 6 hours on each day. The results showed that metaproterenol was consistently superior to placebo in all pulmonary function parameters measured on Days 1 and 30. This difference was statistically significant for peak values and areas under the curves for both FEV1 and FEF25-75%. There were no significant side effects noted. We conclude that metaproterenol metered dose inhaler is safe and effective in the treatment of asthma in children ages 5 to 12 years.

Administration, Inhalation↗