The data presented by Breen et al[1] regarding the outcomes of
patients with COPD are encouraging and lend support to the respiratory
physician often faced with nihilistic attitudes towards ventilating these
patients in acute respiratory failure. However, despite the proposition
by the authors that certain patients with likely poor outcomes might have
been excluded, the ICU stays for both gr...
The data presented by Breen et al[1] regarding the outcomes of
patients with COPD are encouraging and lend support to the respiratory
physician often faced with nihilistic attitudes towards ventilating these
patients in acute respiratory failure. However, despite the proposition
by the authors that certain patients with likely poor outcomes might have
been excluded, the ICU stays for both groups (intubated and non-intubated)
are strikingly short.
This suggests that the threshold for intubation as opposed to non-
invasive ventilation (NIV) may have been lower before 1994 than in current
practice. Although the authors explain the reason for the high levels of
PaO2 on admission to the ICU, it could be that the severity of respiratory
acidosis may have reflected excess oxygen therapy rather than the severity
of the underlying mechanical respiratory failure, thus being more readily
reversible and requiring a shorter period of ventilatory support.
Although the decision to intubate is not solely based upon blood gases,
with the increasing availability of NIV, it might be that a subgroup of
these patients would now be managed using controlled oxygen therapy,
respiratory stimulants and NIV[2].
As a result, I suspect that the physiological state of the patient
that we offer to the ICU in our current practice may be worse than in this
study with commensurate outcomes (longer stays and higher mortality).
Despite this, many patients still do well and studies of this type need to
continue to assess predictors of unfavourable end-points.
Luke Howard MA, DPhil, MRCP.
Department of Respiratory Medicine, Norfolk & Norwich University Hospital, Colney Lane, Norwich, NR4 7UY, UK
References
(1) Breen D, Churches T, Hawker F, Torzillo PJ. Acute respiratory failure
secondary to chronic obstructive pulmonary disease treated in the
intensive care unit: a long term follow up study. Thorax;57:29-33.
(2) Plant PK, Owen JL, Elliott MW. Early use of non-invasive ventilation
for acute exacerbations of chronic obstructive pulmonary disease on
general respiratory wards: a multicentre randomised controlled trial.
Lancet;355:1931-1935.
Dr McFadden is putting forward an interpretation of the small non-
significant decrease in asthma episode contacts seen amongst those with
moderate exposure to passive smoking. In our view this is unwise. The
effect could well be due simply to the play of chance. Further we have
shown that non-clinical factors have a dominant influence on visit
frequency and that the frequency of contacts is a poor measu...
Dr McFadden is putting forward an interpretation of the small non-
significant decrease in asthma episode contacts seen amongst those with
moderate exposure to passive smoking. In our view this is unwise. The
effect could well be due simply to the play of chance. Further we have
shown that non-clinical factors have a dominant influence on visit
frequency and that the frequency of contacts is a poor measure of asthma
morbidity. In consequence our study gives no support at all to the idea
that moderate levels of tobacco smoke suppress asthma. We agree that
further research is needed both into the consequences of passive smoking
and also into the determinants of health care utilisation among children
with asthma.
Iain K Crombie, Professor
Linda Irvine, Research Fellow
Department of Epidemiology and Public Health University of Dundee, Dundee DD1 9SY, UK
We fully appreciate Dr Furness's comments on the limitations of the
definition of asthma based on parents' reports of symptoms and we have
contributed on the subject.[1] Epidemiological studies of asthma have to
rely on reported symptoms,[2][3] but a better understanding of what
parents call wheeze would be of great importance, especially in a
multicultural society. The validity of reported asthma symptoms...
We fully appreciate Dr Furness's comments on the limitations of the
definition of asthma based on parents' reports of symptoms and we have
contributed on the subject.[1] Epidemiological studies of asthma have to
rely on reported symptoms,[2][3] but a better understanding of what
parents call wheeze would be of great importance, especially in a
multicultural society. The validity of reported asthma symptoms has been
demonstrated in adults[4] and the symptoms analysed in the validation were
not dissimilar from those used in our study.
We have discussed that parents' perceptions of asthma may vary
according to ethnicity and social background.[5][6] False positive and
false negative responses could arise if parents mislabel other respiratory
symptoms as wheeze or if persistent wheeze is unrecognised.[7] Persistent
wheeze is unrecognised as asthma in a large percentage of children from
the ethnic minorities and inner city areas. We performed the analysis
using either parental reports of persistent wheeze or asthma attacks in
order to overcome these differences and the results were consistent. We
adjusted for ethnicity and study area in the analysis of the inner city
sample to account for the variation in perception.
References
(1) Jones CO, Qureshi S, Rona RJ, et al. Exercise-induced bronchoconstriction by ethnicity and presence of asthma in British nine
year olds. Thorax 1996;51:1134-6.
(2) Burney PGJ, Chinn S, Rona RJ. Has the prevalence of asthma
increased in children? Evidence from the National Study of Health and
Growth 1973-86. BMJ 1990;300:1306-10.
(3) The International Study of Asthma and Allergies in Childhood
(ISAAC) Steering Committee. Worldwide variations in the prevalence of
asthma symptoms: The International Study of Asthma and Allergies in
Childhood (ISAAC). Eur Respir J 1998;12:315-35.
(4) Burney PG, Laitinen LA, Perdrizet S, et al. Validity and
repeatability of the IUATLD (1984) bronchial symptom questionnaire: an
international comparison. Eur Respir J 1989;2:940-5.
(5) Duran-Tauleria E, Rona RJ, Chinn S, Burney P. Influence of ethnic
group on asthma treatment in children in 1990-1: national cross sectional
study. BMJ 1996;313:148-52.
(6) Duran-Tauleria E, Rona RJ. Geographical and socioeconomic
variation in the prevalence of asthma symptoms in English and Scottish
children. Thorax 1999;54:476-81.
(7) Cane RS, Ranganathan SC, McKenzie SA. What do parents of wheezy
children understand by wheeze? Arch Dis Child 2000;82:327-32.
Intravenous interleukin-5 antagonist has great potential and studies
have shown that it may be beneficial in chronic asthmatics for 3 to 6
months.
Now the understanding of cytokines and their beneficial and harmful
effects are well known but still cure of bronchial asthma appears to be a
remote possibility. Non-compliance in patients is very high and once they
feel better they take medicines irre...
Intravenous interleukin-5 antagonist has great potential and studies
have shown that it may be beneficial in chronic asthmatics for 3 to 6
months.
Now the understanding of cytokines and their beneficial and harmful
effects are well known but still cure of bronchial asthma appears to be a
remote possibility. Non-compliance in patients is very high and once they
feel better they take medicines irregularly.
Effort should be made to make use of usefull cytokines and to raise
their level in asthmatics.
I read with great interest the article of Nakayama et al about tuberculin
responses and risk of pneumonia in immobile elderly patients. It is known
that TH1 cells are important in delayed type hypersensitivity responses to
tuberculin. The authors' findings are important in assessment of
pathogenesis of pneumonia in elderly patients. But I have some doubts
about the analysis of data. The groups were compared...
I read with great interest the article of Nakayama et al about tuberculin
responses and risk of pneumonia in immobile elderly patients. It is known
that TH1 cells are important in delayed type hypersensitivity responses to
tuberculin. The authors' findings are important in assessment of
pathogenesis of pneumonia in elderly patients. But I have some doubts
about the analysis of data. The groups were compared by using Student's t
test although the groups were less than 30. So Mann Whitney U test must be
used instead of Student t test.
I was interested to see the work of Figueroa-Munoz and colleagues
showing an association between obesity and wheeze.[1] I would like to
caution against their conclusion. In their study asthma is defined
according to "asthma attack" and parental reports of wheeze. Several
studies have shown parental reporting of wheeze to be unreliable.[2][3][4]
Please can the authors clarify who defined, "asthma att...
I was interested to see the work of Figueroa-Munoz and colleagues
showing an association between obesity and wheeze.[1] I would like to
caution against their conclusion. In their study asthma is defined
according to "asthma attack" and parental reports of wheeze. Several
studies have shown parental reporting of wheeze to be unreliable.[2][3][4]
Please can the authors clarify who defined, "asthma attack?" I see that
their data independent of reported wheeze supports their conclusion but it
would be a stronger argument if parents were not the only ones relied on
to report asthma symptoms. The assumption that all that wheezes is asthma
may lead to the omission of other diagnoses or the inappropriate
prescription of inhaled corticosteroids.
May I be so bold as to suggest an
alternative title for this important work: "Association of obesity and
respiratory symptoms in children"?
References
(1) Figueroa-Munoz JI, Chinn S, Rona RJ. Association of obesity and asthma in 4-11 year old children in the UK Thorax 2001;56:133-7.
(2) Elphick HE, Sherlock P, Foxall G et al. Survey of respiratory sounds in infants. Arch Dis Child 2001;84:35-9.
(3) Cane RS, McKenzie SA. Parents' interpretations of children's respiratory symptoms on video Arch Dis Child 2001;84:31-4.
(4) Cane RS, Ranganathan SC, McKenzie SA. What do parents' of wheezy
children understand by "wheeze". Arch Dis Child 2000;82:327-32.
The observational data presented by Macfarlane et al on the aetiology of
acute lower respiratory tract illness in the community[1] confirm that the
often stated assertion that these illnesses are usually caused by viral
infection is incorrect. The high prevalence of bacteriological and
atypical pathogens, and in particular the high prevalence of C pneumoniae
in these patients is of interest and points to the n...
The observational data presented by Macfarlane et al on the aetiology of
acute lower respiratory tract illness in the community[1] confirm that the
often stated assertion that these illnesses are usually caused by viral
infection is incorrect. The high prevalence of bacteriological and
atypical pathogens, and in particular the high prevalence of C pneumoniae
in these patients is of interest and points to the need for further
studies to clarify the clinical significance of these isolates. The lack
of correlation between indirect evidence of infection (radiographic and
CRP levels), GP assessment of the need for antibiotics and pathogen
isolation are also of great interests and have important messages for
those working in the community.
The outcome conclusions from this study do however need to be treated with
some caution.
The authors state that outcomes were similar whether or not
antibiotics were used, but as this was an unrandomised observational
study, we cannot say that the groups of patients who were and were not
given antibiotics by the GPs in the study were comparable. The experienced
GP researchers in this study may well have had particular reasons for
giving or withholding antibiotics, and the significance of similar
reconsultation rates in these groups is open to interpretation.
In the accompanying editorial,[2] the authors state that systematic
reviews of randomised controlled trials of antibiotic prescription for
acute bronchitis do not support antibiotic treatment, and evidence based
educational initiatives aimed at GPs are advocated as one of the
strategies to alter clinical behaviour.
Having recently reviewed the
literature on this important clinical topic myself,[3] I cannot agree with
their assessment of the current evidence. The more recent review they
quote[4] has been criticised on methodological grounds, and the most
recent and extensive systematic review of this clinical problem, published
on the Cochrane database,[5] comes to very different conclusions,
commenting that "the review confirmed the impression of clinicians that
antibiotics have some beneficial effects in acute bronchitis". The
benefits are probably small and confined to certain patient subgroups, but
the quantification of benefit and the definition of the characteristics of
responder groups need further studies to delineate.
The world literature
currently consists of eight randomised controlled trials of variable
quality, some 20 years old, that use different antibiotic regimens and
different outcome measures. Several of these studies have concluded that
the antibiotic regimens used did improve outcomes.
The recent enquiry into community acquired pneumonia deaths in young
adults published in this journal,[6] revealed that the primary care
management of these patients at the severe end of lower respiratory tract
infection spectrum was deficient in many cases - three quarters of patients
had seen their GP for the illness without a correct diagnoses and few had
received antibiotics from their GP. There are many areas of uncertainty
remaining in this field, and while observational studies such as this help
to bring some clarity into this confused area of daily clinical practice,
well designed randomised controlled trials are still needed to produce the
evidence based guidance that GPs require. The current evidence is
inadequate to meet the challenge identified by Macfarlane et al,[1] that
of identifying the cohort of patients who will benefit from antibiotics.
Dr Mike Thomas
Clinical Research Fellow
Department of Primary Care Respiratory Medicine
University of Aberdeen, UK
References
(1) Macfarlane J, Holmes W, Gard P, Macfarlane R, Rose D, Weston V.
et al. Prospective study of the incidence, aetiology and outcome of lower
respiratory tract illness in the community. Thorax 2001;56:109-14.
(2) Steele K, Gormley G, Webb CH. Management of adult lower
respiratory tract infection in primary care. Thorax 2001;56:88.
(3) Thomas M. The management of acute respiratory tract infection in
adults in primary care. Primary Care Respiratory Journal 200;9:4-7.
(4) Fahey T, Stocks N, Thomas T. Quantitative systematic review of
randomised controlled trials comparing antibiotic with placebo for acute
cough in adults. BMJ 1998;316:910.
(5) Becker L, Glazier R, McIsaac W, and et al. Antibiotics for acute
bronchitis. Douglas R, Bridges-Webb C, Glasziou P, and et al. (1). 1998.
Oxford, Update software. Acute Respiratory Infections Module of the
Cochrane database of systematic reviews.
(6) Simpson JCG, Macfarlane JT, Watson J, Woodhead M. A national
confidential enquiry into community acquired pneumonia deaths in young
adults in England and Wales. Thorax 2000;55:1040-5.
If the abstract indicates correctly that children of totally non-smoking parents were not included in the study, I see that as a significant weakness.
The study found, as might be expected by many, an increase in contacts for asthma episodes among children most heavily exposed to environmental tobacco smoke (ETS).
However, it also found a non-significant but noteworthy decrease in asthma epi...
If the abstract indicates correctly that children of totally non-smoking parents were not included in the study, I see that as a significant weakness.
The study found, as might be expected by many, an increase in contacts for asthma episodes among children most heavily exposed to environmental tobacco smoke (ETS).
However, it also found a non-significant but noteworthy decrease in asthma episode contacts among those with "moderate" exposure as opposed to "low" exposure. If non-smoking parents (which would presumably usually
have children with *extremely* low exposure) had been included as a study group as well, we might have seen a continuation of the U-shaped curve indicating support for the idea that moderate levels of tobacco smoke in
the air might act in some way as a suppressor to asthma or asthma episodes
among children regularly exposed to such. Such a finding would also be in
line with the observed increase in asthma among American children over the
last few decades that seems to form a strikingly inverse relationship with
the exposure of American children to secondary smoke in the home and such
venues as fast-food restaurants and child care facilities.
Such a theory is of course anathema to the standard view that *any* exposure is "bad" for children and others, but it's possible that it could prove correct if properly studied.
I read with interest this article in Thorax and have been worried by the comments in "Pulse" which followed (9 December 2000).
The lack of information about the general practitioner (GP) consultations, and the non-
availability of records is alarming and dispiriting. Particularly when
nowadays much information is computerised and records can in emergency
situations, given the hard work of Health...
I read with interest this article in Thorax and have been worried by the comments in "Pulse" which followed (9 December 2000).
The lack of information about the general practitioner (GP) consultations, and the non-
availability of records is alarming and dispiriting. Particularly when
nowadays much information is computerised and records can in emergency
situations, given the hard work of Health Authorities pass between
practices in days.
It would be helpful to know what physical signs might have been
missed, indeed the selection process does not define presenting clinical
signs (beyond absence of life). So we have no denominator of cases where
we might need to think harder to avoid these events. As an habitual
"examiner" after ten years in general practice (and ten in hospital
medicine) I have been surprised by the paucity of physical signs in
patients with cough fever and purulent sputum. In these days of
evidenced based guidelines leading us away from the use of antibiotics we
need something hard to guide us to avoid the tragic but extremely rare
cases described.
It is a sad fact that subtle physical signs can be missed - even if
they are indeed present. Ten years in general practice has taught me
that serious illness changes quickly from minor symptoms to dire straits.
The only similar case in my recollection was a young woman sent home from
casualty to return moribund to hospital the same day with lobar pneumonia.
Steven Stern, MB ChB BSc MRCP
Principal in General Practice
Dear Editor
The data presented by Breen et al[1] regarding the outcomes of patients with COPD are encouraging and lend support to the respiratory physician often faced with nihilistic attitudes towards ventilating these patients in acute respiratory failure. However, despite the proposition by the authors that certain patients with likely poor outcomes might have been excluded, the ICU stays for both gr...
Dr McFadden is putting forward an interpretation of the small non- significant decrease in asthma episode contacts seen amongst those with moderate exposure to passive smoking. In our view this is unwise. The effect could well be due simply to the play of chance. Further we have shown that non-clinical factors have a dominant influence on visit frequency and that the frequency of contacts is a poor measu...
We fully appreciate Dr Furness's comments on the limitations of the definition of asthma based on parents' reports of symptoms and we have contributed on the subject.[1] Epidemiological studies of asthma have to rely on reported symptoms,[2][3] but a better understanding of what parents call wheeze would be of great importance, especially in a multicultural society. The validity of reported asthma symptoms...
Intravenous interleukin-5 antagonist has great potential and studies have shown that it may be beneficial in chronic asthmatics for 3 to 6 months.
Now the understanding of cytokines and their beneficial and harmful effects are well known but still cure of bronchial asthma appears to be a remote possibility. Non-compliance in patients is very high and once they feel better they take medicines irre...
I read with great interest the article of Nakayama et al about tuberculin responses and risk of pneumonia in immobile elderly patients. It is known that TH1 cells are important in delayed type hypersensitivity responses to tuberculin. The authors' findings are important in assessment of pathogenesis of pneumonia in elderly patients. But I have some doubts about the analysis of data. The groups were compared...
I was interested to see the work of Figueroa-Munoz and colleagues showing an association between obesity and wheeze.[1] I would like to caution against their conclusion. In their study asthma is defined according to "asthma attack" and parental reports of wheeze. Several studies have shown parental reporting of wheeze to be unreliable.[2][3][4]
Please can the authors clarify who defined, "asthma att...
The observational data presented by Macfarlane et al on the aetiology of acute lower respiratory tract illness in the community[1] confirm that the often stated assertion that these illnesses are usually caused by viral infection is incorrect. The high prevalence of bacteriological and atypical pathogens, and in particular the high prevalence of C pneumoniae in these patients is of interest and points to the n...
If the abstract indicates correctly that children of totally non-smoking parents were not included in the study, I see that as a significant weakness.
The study found, as might be expected by many, an increase in contacts for asthma episodes among children most heavily exposed to environmental tobacco smoke (ETS).
However, it also found a non-significant but noteworthy decrease in asthma epi...
I read with interest this article in Thorax and have been worried by the comments in "Pulse" which followed (9 December 2000).
The lack of information about the general practitioner (GP) consultations, and the non- availability of records is alarming and dispiriting. Particularly when nowadays much information is computerised and records can in emergency situations, given the hard work of Health...
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