Biomedical subjects

J Kolbe

Publications and source records attributed to J Kolbe.

At least 19 recordsLinked to original sources

PubMed2006

Overnight prescription of oxygen in long term oxygen therapy: time to reconsider the guidelines?

BACKGROUND: Guidelines for long term oxygen therapy (LTOT) recommend increasing oxygen flow by 1 l/min overnight. A study was undertaken in patients with COPD on LTOT to determine the prevalence of overnight desaturation if the usual oxygen flow rate is not increased at night, whether resting oxygen saturation predicts overnight desaturation, and whether overnight desaturation correlates with health related quality of life (HRQL) and sleep quality. METHODS: A cross sectional prospective study was performed on consecutive patients with COPD on LTOT attending our regional outpatient oxygen service. All patients fulfilled standard criteria for LTOT, had been established on LTOT at a flow to achieve resting oxygen saturations >90%, but had not been instructed to increase oxygen flow overnight. Overnight desaturation was defined as <90% for > or =30% of the night on either of two consecutive nights. HRQL was evaluated with the SF-36 Health Survey Questionnaire, Chronic Respiratory Questionnaire, and the Pittsburgh Sleep Quality Index. RESULTS: Thirty eight patients (63% men) of mean (SD) age 73.5 (8.04) years and mean (SD) forced expiratory volume in 1 second 0.77 (0.35) l were evaluated. Overnight desaturation occurred in six (16%; 95% CI 4 to 27). Desaturators had mean (SD) resting oxygen saturation on room air of 88 (4.2)% compared with 90 (4.1)% in non-desaturators (p = 0.15), and corrected saturations of 93 (2.0)% versus 94 (2.0)% (p = 0.18). HRQL and sleep quality were poor but did not differ between desaturators and non-desaturators. CONCLUSIONS: Most patients did not exhibit overnight desaturation despite not increasing their LTOT prescription overnight. These results challenge the recommendation of routinely increasing overnight oxygen flow in patients receiving LTOT.

Aged↗

PubMed2006

Short-burst oxygen therapy for COPD patients: a 6-month randomised, controlled study.

Short-burst oxygen therapy (SBOT) remains widely advocated for patients with chronic obstructive pulmonary disease (COPD), despite a lack of supporting evidence. The aim of this randomised, double-blind, placebo-controlled, parallel group study was to determine whether SBOT improves health-related quality of life (HRQL) or reduces acute healthcare utilisation in patients discharged following an acute exacerbation of COPD. Consecutive patients were screened; 78 of 331 were eligible for randomisation to cylinder oxygen, cylinder air or usual care following discharge. Patients were elderly with high acute healthcare utilisation, forced expiratory volume in one second of <1 L and had dyspnoea limiting daily activity but were not hypoxaemic at rest. Over the 6-month study period, there were no significant differences between patient groups in HRQL (Chronic Respiratory Questionnaire (CRQ), 36-item Short-Form Health Survey, Hospital Anxiety and Depression Scale) except for CRQ emotion domain. There were no significant differences in acute healthcare utilisation. Time to readmission was greatest in the usual care group. Cylinder use was high initially, but rapidly fell to very low levels within weeks in both cylinder oxygen and air groups. In conclusion, the availability of short-burst oxygen therapy for chronic obstructive pulmonary disease patients discharged from hospital following an acute exacerbation did not improve health-related quality of life or reduce acute healthcare utilisation. These results provide no support for the widespread use of short-burst oxygen therapy.

Acute Disease↗

PubMed2006

The endurance shuttle walking test: a responsive measure in pulmonary rehabilitation for COPD patients.

BACKGROUND: The endurance shuttle walk test (ESWT) is a standardized externally controlled constant paced field test for the assessment of endurance capacity in chronic lung disease. The ESWT has been advocated as a simple, acceptable, repeatable and responsive outcome measure for COPD patients undergoing pulmonary rehabilitation, but has not been formally compared with the more commonly used field walking test, the six-minute walk (6MW). We aimed to determine: 1) the responsiveness of the ESWT in COPD patients attending a hospital-based pulmonary rehabilitation programme, and 2) to compare the responsiveness of the ESWT with the 6MW. METHODS: Consecutive COPD patients, referred for a standard 8 week pulmonary rehabilitation programme, were recruited. Outcome parameters studied at baseline and completion of rehabilitation programme (8 weeks) included spirometric lung volumes, resting oxygen saturation, breathlessness scored pre and post exercise (modified Borg dyspnoea score), 6MW, ESWT, health-related quality of life (Chronic Respiratory Questionnaire) and Hospital Anxiety and Depression (HAD) scale. The incremental shuttle was employed to predict VO2 peak; 85% VO2 peak was used to determine the walk speed for the ESWT. RESULTS: Twenty stable COPD patients (11 male), mean (SD), age 71, (9) FEV1 0.95 (0.51), resting SpO2 95% (2) 6MW distance (m) 351 (104) and ESWT distance (m) 313 (193) were studied. Three patients did not complete their rehabilitation programme. Following rehabilitation, there were significant improvements in 6MW, ESWT, total CRQ and anxiety domain (HAD). The 6MW distance increased by 17% (47 m 95%CI 3, 90), while the ESWT increased by 92% (302 m 95%CI 104, 501). CONCLUSION: The ESWT is a simple, acceptable and highly responsive outcome measure for COPD patients undergoing a pulmonary rehabilitation programme. The ESWT has potential advantages in that it may be more responsive than the 6MW.

Aged↗

PubMed2005

Nitric oxide levels and ciliary beat frequency in indigenous New Zealand children.

New Zealand children's morbidity from respiratory disease is high. This study examines whether subclinical ciliary abnormalities underlie the increased prevalence of respiratory disease in indigenous New Zealand children. A prospective study enrolled a group of healthy children who were screened for respiratory disease by questionnaire and lung function. Skin-prick tests were performed to control for atopy. Exhaled and nasal NO was measured online by a single-breath technique using chemiluminescence. Ciliary specimens were obtained by nasal brushings for assessment of structure and function. The ciliary beat frequency (CBF) (median CBF, 12.5 Hz; range, 10.4-16.8 Hz) and NO values (median exhaled NO, 5.6 ppb; range, 2.3-87.7 ppb; median nasal NO, 403 ppb; range, 34-1,120 ppb) for healthy New Zealand European (n=58), Pacific Island (n=61), and Maori (n=16) children were comparable with levels reported internationally. No ethnic differences in NO, atopy, or CBF were demonstrated. Despite an apparently normal ciliary beat, the percentage of ciliary structural defects was 3 times higher than reported controls (9%; range, 3.6-31.3%), with no difference across ethnic groups. In conclusion, it is unlikely that subclinical ciliary abnormalities underlie the increased prevalence of respiratory disease in indigenous New Zealand children. The high percentage of secondary ciliary defects suggests ongoing environmental or infective damage.

Adolescent↗

PubMed2005

The Dartmouth COOP Charts: a simple, reliable, valid and responsive quality of life tool for chronic obstructive pulmonary disease.

The negative impact of chronic obstructive pulmonary disease (COPD) on health-related quality of life (HRQL) is substantial. Measurement of HRQL is increasingly advocated in clinical practice; traditional outcome measures such as lung function are poorly responsive. However many HRQL tools are not user-friendly in the clinic setting. Hence HRQL is often neglected. The Dartmouth Cooperative Functional Assessment Charts (COOP) have the requisite attributes of a tool suitable for routine clinical practice: they are simple, reliable, quick and easy to perform and score and well accepted. We aimed to determine the reliability, validity and responsiveness of the COOP in patients with significant COPD. HRQL was assessed during a prospective, randomised, placebo-controlled, double-blind, 12 week cross-over interventional study of ambulatory oxygen in patients (n = 50) with COPD. Test-retest reliability of the COOP domains was only modest however it was measured over a 2 month period. Significant correlations ranging between 0.4 and 0.8 were observed between all comparable domains of the COOP and the Medical Outcomes Study 36-item Short-form Health Survey, Chronic Respiratory Questionnaire (CRQ) and Hospital Anxiety and Depression (HAD) scale. Following ambulatory oxygen significant improvements were noted in all CRQ and HAD domains. Several domains of the generic SF-36 (role emotional, social functioning, role-physical) showed significant improvements. Comparable domains of the COOP (social activities, feelings) also showed significant improvements. The COOP change in health domain improved very significantly. The COOP is a simple, reliable HRQL tool which proved valid and responsive in our study population of COPD patients and may have a valuable role in routine clinical practice.

Activities of Daily Living↗

PubMed2004

Long-term oxygen therapy improves health-related quality of life.

Guidelines for the prescription of long-term oxygen therapy (LTOT) in hypoxemic COPD patients are based on two landmark studies in which survival was the primary outcome. Such patients are importantly symptomatic with poor health-related quality of life (HRQL) but the effect of LTOT on HRQL remains uncertain. We undertook a prospective longitudinal interventional study of consecutive COPD patients referred to our regional oxygen service; n = 43 fulfilling criteria and commenced on LTOT, n = 25 not fulfilling criteria and continued on standard care. HRQL was measured at baseline, 2 and 6 months. Both patient groups had severe COPD as defined by mean FEV1 < 35% predicted. At baseline the LTOT group demonstrated significantly worse HRQL as defined by the Chronic Respiratory Questionnaire (CRQ) (fatigue, emotional function, mastery and total scores), total generic Dartmouth COOP Charts and anxiety domain of the Hospital Anxiety and Depression scale. Significant improvements in HRQL were noted at 2 and 6 months in the LTOT group. Conversely the non-LTOT group demonstrated a progressive decline in HRQL. Using validated criteria for a minimal clinically significant improvement in CRQ, there were 28 (67%) and 26 (68%) 'responders' at 2 and 6 months respectively in the LTOT group. The introduction of LTOT to patients with severe COPD fulfilling standard criteria was associated with early significant improvements in HRQL with sustained or further response at 6 months.

Aged↗

PubMed2004

Increased risk of adverse events when changing intravenous immunoglobulin preparations.

Intravenous immunoglobulin (IVIG) therapy has represented a major advance in the treatment of patients with primary immune deficiency disorders. In September 2000 a new IVIG formulation, Intragam P, was introduced into clinical use. Intragam P is prepared by delipidation of pooled plasma followed by an ion exchange chromatography step to eliminate immunoglobulin aggregates. It is then pasteurized for 10 h at 60 degrees C for viral inactivation before storage at pH 4.25 in 10% maltose. We report initial clinical experience with this new preparation. The details of adverse reactions of patients who received the new preparation were gathered shortly after it became apparent there was a change in IVIG formulation. Seven of 49 patients receiving Intragam P spontaneously reported adverse effects, which were temporally related to infusions. Subsequently, all seven patients have been able to tolerate the product with prophylactic use of antihistamines and paracetamol. This case series indicates that long-term tolerance of an older IVIG product does not necessarily equate to tolerance to a newer product, even if technically superior. Caution should be exercised when changing IVIG products, as they are not biologically equivalent.

Adult↗

PubMed2003

Short-burst oxygen immediately before and after exercise is ineffective in nonhypoxic COPD patients.

Short-burst oxygen therapy (SBOT) remains an unproven treatment for reduction of exertional dyspnoea in chronic obstructive pulmonary disease (COPD). This study aimed to assess whether SBOT before exercise reduces dyspnoea or improves performance, and whether SBOT after exercise reduces dyspnoea during recovery. Twenty-two clinically stable COPD patients (mean forced expiratory volume in one second 34% predicted, mean resting saturation 94%) attended a respiratory gymnasium and undertook four 6-min walk (6MW) tests at each of two sessions, 1 week apart. Cylinder air or oxygen was administered single-blind in random order for 5 min prior to the first two 6MW and during recovery following the final two 6MW. Dyspnoea was self-rated by subjects using the modified Borg scale. There was no significant difference in mean 6MW distance or final Borg score for air and oxygen given before exercise. There was also no significant difference in mean time-to-resting Borg score for air and oxygen given after exercise. Only two subjects demonstrated a clinically significant and consistent reduction in dyspnoea for oxygen compared with air either before or after exercise. Overall, short-burst oxygen therapy neither reduced dyspnoea nor improved performance. This study does not support the use of short-burst oxygen therapy either immediately before or after exercise.

Aged↗

PubMed2002

Case-control study of severe life threatening asthma (SLTA) in adults: psychological factors.

BACKGROUND: Severe life threatening asthma (SLTA) is important in its own right and as a proxy for asthma death. In order to target hospital based intervention strategies to those most likely to benefit, risk factors for SLTA among those admitted to hospital need to be identified. Adverse psychological factors are purported risk factors for asthma death and SLTA /near fatal asthma. A study was undertaken to determine whether, in comparison with patients admitted to hospital with acute asthma, those with SLTA have specific adverse psychological factors. METHODS: A case-control study was undertaken. Cases (n=77) were admitted to the intensive care unit with SLTA (mean (SD) pH 7.17 (0.15), PaCO(2) 10.7 (5.0) kPa). Controls (n=239) were admitted to general wards with acute asthma and were matched only by date of index attack. An interviewer administered questionnaire was undertaken 24-48 hours after admission. A random sample of community based asthmatics was recruited to provide normative data on asthmatics for comparison with cases and hospital controls. RESULTS: The risk of SLTA increased with age (OR 1.04/year, 95% CI 1.01 to 1.07) and was less for women (OR 0.36, 95% CI 0.20 to 0.68). These variables were controlled for in all further analyses. There was a high prevalence of psychological disorder in both cases and matched controls, but there was no difference in prevalence of caseness for anxiety or depression, total (or individual) life events in last 12 months, availability of general or disease specific social support, nor in any of the domains of the Attitudes and Beliefs about Asthma Questionnaire (emotional (mal) adjustment, doctor-patient relationship, stigma, self-efficacy). Cases (SLTA) were less likely to have had previous emotional counselling (25% v. 35%, p<0.05). However, when comparison was made with a community based group of asthmatic patients, those admitted to hospital with acute asthma (SLTA and hospital controls) had a higher prevalence of anxiety and depression, higher total life events, and higher prevalence of certain specific life events. CONCLUSIONS: There was considerable psychological morbidity generally (and anxiety specifically) in those admitted with acute asthma. Specific adverse psychological factors were not risk factors for SLTA, when comparison was made with those admitted to hospital with acute asthma, but adverse psychological factors were a risk factor for hospitalisation for acute asthma (including SLTA). Psychological risk factors for adverse events in asthma are dependent both on the type of event under study and the comparison group used.

Adolescent↗

PubMed2002

Management of solitary pulmonary nodules: how do thoracic computed tomography and guided fine needle biopsy influence clinical decisions?

BACKGROUND: Computed tomography (CT) and fine needle guided biopsy (FNB) are often used in the assessment of patients with lung nodules. The influence of these techniques on clinical decision making has not been quantified, especially for small solitary pulmonary nodules (SPN) where the probability of malignancy is lower. A study was undertaken to determine the effect of CT and FNB derived information on clinical decision making in patients with a solitary pulmonary nodule < or = 3 cm in diameter on initial chest radiography. METHODS: Clinical, physiological, and outcome data on 114 patients with an SPN < or = 3 cm who had subsequent thoracic CT and FNB were extracted from the records of a specialist cardiorespiratory hospital in Auckland, New Zealand. Chest radiographs and CT scans were reported according to specified criteria by a thoracic radiologist. Computer generated summary sheets were used to present cases to each of six clinicians. Each case was presented three times: (1) with clinical data and chest radiograph only; (2) with the addition of the CT report; and (3) with all data including the result of the FNB. Clinicians were asked to specify their management on each occasion and to estimate the probability of the lesion being malignant. Reproducibility was assessed by re-evaluating 24 cases 1 month later. RESULTS: 33 (29%) nodules were benign, 35 (31%) nodules (malignant) were resected with negative node sampling, and 46 (40%) had a non-curative outcome (radiotherapy, incomplete resection, refused therapy). Intra-clinician decision making was consistent for all three levels of clinical data (median kappa values 0.79-0.89). Agreement between clinicians on the need for surgery was lowest with chest radiography alone (kappa=0.33), rose with CT information (kappa=0.44), and increased further with the addition of the FNB data (kappa=0.57). The proportion of successful decisions on surgical intervention (against the known outcome) increased with the addition of CT reports and further with FNB reports (p=0.006, Friedman's test). The major benefit of the information added by CT and FNB reports was a reduction in unnecessary surgery, especially when the clinical perception of pre-test probability of malignancy was intermediate (31-70%). FNB data contributed most to the benefit (p<0.001). The addition of CT and FNB was cost efficient and can be applied specifically to patients with a low or intermediate probability of malignancy. CONCLUSION: Both CT and FNB make cost effective contributions to the clinical management of SPN < or = 3 cm in diameter by reducing unnecessary operations and increasing agreement between physicians on the need for surgery.

Adult↗

PubMed2002

Ambulatory oxygen improves quality of life of COPD patients: a randomised controlled study.

It is unknown whether acute response to ambulatory oxygen (O2) predicts longer term improvement in health-related quality of life (HRQL) in chronic obstructive pulmonary disease (COPD) patients. The aims of this study were 1) to assess the short-term clinical impact, as determined by HRQL, of ambulatory O2 in a 12-week, double-blind, randomised crossover study of O2 (versus cylinder compressed air) of dyspnoeic but not chronically hypoxic COPD patients with exertional desaturation < or = 88% (n=41), and 2) to determine whether either baseline characteristics or acute response to O2 predicts short-term (12 weeks) response. Primary outcome measures were Chronic Respiratory Questionnaire (CRQ), Hospital Anxiety and Depression scale and the short form (SF)-36. Improvements were seen in all domains of the CRQ for cylinder O2 compared with cylinder air. Significant improvements were also noted in anxiety and depression and in certain domains of the SF-36. There were 28 (68%) acute responders to cylinder O2 (defined as increase in 6-min walk > or = 54 m or decrease in post-Borg dyspnoea > or = 1) and 23 (56%) short-term responders (defined as clinically significant improvement in CRQ). However, acute and short-term responses were not correlated with no predictors of short-term response identified. At study completion, 14 (41%) of acute or short-term responders did not want to continue therapy, with 11 citing poor acceptability or tolerability. Short-term ambulatory oxygen is associated with significant improvements in health-related quality of life. These benefits cannot be predicted by baseline characteristics or acute response. Despite acute or short-term response, a substantial proportion of patients declined ambulatory oxygen.

Aged↗

PubMed2001

Spirometric lung volumes in the adult Pacific Islander population: comparison with predicted values in a European population.

OBJECTIVE: Prediction equations for spirometric lung volumes have been developed mainly in Europe and North America and may not be relevant to Pacific Islanders. This study was undertaken to determine whether currently available prediction equations adequately describe spirometric lung volumes in the asymptomatic adult Pacific Islander population. METHODOLOGY: Healthy asymptomatic Pacific Island adults aged 15-70 years were recruited. Pulmonary function was measured in the laboratory at Green Lane Hospital, Auckland, New Zealand, in accordance with American Thoracic Society standards. Measured results were compared with predicted values derived from four sets of prediction equations relevant to, or currently used in, New Zealand. RESULTS: A total of 101 volunteers took part in the study; mean age 28 years (range 18-66 years), 39% male, body mass index = 32 (range 22-54). For forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC), when measured values were compared with reference values, the slopes of the regression lines were not significantly different from 1 and the intercepts were not significantly different from zero. Prediction equations derived for African-Americans did not provide a better fit than the prediction equations for Caucasians. Predictions were improved when ideal rather than actual bodyweight was used. CONCLUSION: Respiratory parameters (FEV1 and FVC) in healthy asymptomatic adult Pacific Islanders in New Zealand are adequately described by currently available prediction equations and no adjustment for ethnicity is required.

Adolescent↗

PubMed2001

Characteristics of patients with lung cancer under the age of 45 years: a case control study.

OBJECTIVE: The aim of this study was to define the clinical and pathological features associated with lung cancer diagnosed in persons under the age of 45 compared with lung cancer in an older population of greater than 45 years. METHODOLOGY: A case control study was undertaken. Cases were defined as patients diagnosed with lung cancer under the age of 45 years. Controls were lung cancer patients over 45 years matched only for the date of diagnosis. Up to four controls were selected for each case. A retrospective review was undertaken of the records of a single tertiary respiratory institution which served a population of 1.2 million. RESULTS: Forty-eight cases of lung cancer (< 45 years of age) were identified and were compared to 123 matched controls with lung cancer (> 45 years of age). Of the cases 67% were female compared with 32% female cases in the control group (P < 0.01). The rate of adenocarcinoma was significantly higher among cases (48% vs 27%, P=0.001), while squamous cell carcinoma was more common in the controls (35% vs 17% P =0.001). Smoking was common in both groups although less so among cases (79% vs 95%, P=0.001)). There was no difference in survival rates between the cases (11 months) compared with controls (8 months) (P=0.1). CONCLUSIONS: Young lung cancer patients were predominantly female and adenocarcinoma accounted for a disproportionate number of the histological types. Cigarette smoking appears to be the main aetiological agent but as 21% of the patients under 45 years were non-smokers, other factors (genetic/hormonal) may also contribute. This study has not demonstrated a worse outcome in younger patients.

Adenocarcinoma↗

PubMed2000

Cystic fibrosis diagnosed in adult patients.

AIM: To review the presentation, diagnosis and long-term, clinical follow-up of cystic fibrosis in adult patients diagnosed in adulthood at Green Lane Hospital. METHODS: A retrospective review of the case notes of patients with cystic fibrosis diagnosed in adulthood at Green Lane Hospital or referred there for management. Information was collected on diagnostic tests, including sweat tests and genotyping. Relevant family history was documented as were spirometry results and microbial colonisation. RESULTS: Six patients conclusively fulfilled the diagnostic criteria for cystic fibrosis. There was a wide range of ages at diagnosis (18-68) and half of the patients had a positive family history. A single mutation was identified in all, but in only one of the cases was the second mutation identified. All patients had evidence of bronchopulmonary suppuration and all had retained pancreatic function. Colonisation with P aeruginosa was associated with marked impairment in lung function. CONCLUSION: The patients at Green Lane Hospital represent part of the broad-spectrum disease in adult patients diagnosed with cystic fibrosis and highlight the differences between this group and those patients diagnosed in childhood with the more classical phenotype. Patients generally have less severe lung disease and retain pancreatic function. Sweat testing is useful diagnostically but gene testing is of limited value in making the diagnosis.

Adolescent↗

PubMed2000

Inhaled steroids for bronchiectasis.

BACKGROUND: Bronchiectasis is a progressive condition characterised by irreversible destruction and dilatation of airways, generally associated with chronic bacterial infection. The two distinct therapeutic goals are: symptom control and reduction in morbidity; and prevention of progression of the underlying disease. OBJECTIVES: To determine whether regular inhaled corticosteroids produce improvement in symptom control and whether they beneficially influence the natural history of the disease. SEARCH STRATEGY: The Cochrane Airways Group RCT register and Cochrane Controlled Clinical Trials Register were searched using the following search terms; bronchiectasis AND [corticosteroid* OR beclomethasone OR budesonide OR fluticasone OR triamcinolone OR flunisolide]. Bibliographies of each included RCT was searched for additional trials. Pharmaceutical companies that manufacture inhaled corticosteroids were also contacted. SELECTION CRITERIA: Only randomised double blind studies controlled trials were included. Patients with radiographic evidence of bronchiectasis were included, but patients with cystic fibrosis were excluded. DATA COLLECTION AND ANALYSIS: Data was extracted by one of the reviewers (FR). Continuous outcomes were analysed as effect sizes (weighted mean difference or as standardised mean difference with 95% confidence intervals). MAIN RESULTS: Only two trials on a total of 54 patients could be included. The studies were of 4 and 6 weeks duration. Inhaled corticosteroids had no significant effect on any of the outcomes included in this review, however there was a trend towards improving: FEV1, FVC, PEFR, RV and DLco. REVIEWER'S CONCLUSIONS: In bronchiectasis, regular use of inhaled corticosteroids may improve lung function. The available studies were too short and too small to provide any clear evidence to guide practice. Larger and longer studies should include rate of decline of lung function, exacerbation frequency, hospitalisations and healthy status as outcomes.

Administration, Inhalation↗

PubMed2000

Increased nitric oxide production in the respiratory tract in asymptomatic pacific islanders: an association with skin prick reactivity to house dust mite.

BACKGROUND: Exhaled nitric oxide (NO) is increased in asthma and may also be increased in subclinical airway inflammation. The relationship between atopy and subclinical airway inflammation in the pathogenesis of asthma remains unclear. We have evaluated the relationship between exhaled NO levels and skin prick test reactivity to 8 common allergens in 64 asymptomatic adult Pacific Islanders. Pacific Islanders were studied as a racial group with major morbidity from asthma. OBJECTIVE: Our purpose was to determine whether asymptomatic subjects with skin prick test reactivity to common allergens have elevated NO levels. METHODS: All subjects underwent full lung function testing and skin prick testing. Exhaled and nasal NO levels were measured by chemiluminescence (Logan LR2000 analyzer) with use of the single-breath and breath-holding techniques, respectively. RESULTS: House dust mite (HDM) reactivity was seen in 38 of 64 (56%). Exhaled NO levels (median 8.9 ppb, range 2.9-47.3 ppb) and nasal NO levels (527.5 +/- 181.5 ppb) lay above the normal European range in 30% and 25% of subjects, respectively. HDM reactivity was associated with higher exhaled NO levels (P <. 0005) and higher nasal NO levels (P =.01). In HDM-sensitive subjects the wheal size for HDM correlated with exhaled NO levels (r = 0.35, P =.04) and nasal NO levels (r = 0.40, P =.01). On multivariate analysis, exhaled NO levels were independently and positively related to the severity of HDM reactivity (P =.01) and nasal NO levels (P <.02), equation R(2) = 0.27. CONCLUSION: NO levels are elevated in a significant proportion of asymptomatic Pacific Islanders and are associated with HDM sensitivity. This may denote subclinical airway inflammation in this population and suggests that exposure to HDM in atopic individuals might play an important role in the early pathogenesis of asthma.

Adolescent↗

PubMed2000

Simple and inexpensive but highly discriminating method for computer-assisted DNA fingerprinting of Pseudomonas aeruginosa.

We describe here a method for computer-assisted fingerprinting of Pseudomonas aeruginosa. In this method, DNA is digested with SalI, and bands with molecular sizes of >/=9.7 kb are visually scored after electrophoresis on agarose gels. Pattern scores are entered into a Microsoft Excel database. In scoring, the number of bands within each of a set of molecular size ranges is scored, rather than the absolute molecular size of each band, substantially enhancing the speed and reproducibility of the method, while eliminating the need for using expensive gel scanning equipment and software. Pattern scores are used to generate matrices of genetic distance values, which can be visualized in neighbor-joining trees. The method reliably distinguishes two epidemiologically unrelated isolates in 99.3% of all comparisons. The genetic relationships between isolates observed with the method were consistent with those obtained by analysis of two P. aeruginosa genes, indicating that it provides valid estimates of genetic divergence between isolates. Using the method, respiratory tract isolates from cystic fibrosis patients in Green Lane Hospital in Auckland, New Zealand, were shown to be genetically less diverse than epidemiologically unrelated isolates from other patients. This finding was not due to the existence of clusters of related strains specialized toward colonization of the respiratory tract and thus was indicative of transmission between patients. Analysis of multiple isolates from individual cystic fibrosis patients suggested that up to five separate clusters of genetically related strains may simultaneously be present in a patient. The method described should significantly enhance our ability to investigate the epidemiology of P. aeruginosa.

Bacterial Outer Membrane Proteins↗

PubMed2000

Case-control study of severe life threatening asthma (SLTA) in adults: demographics, health care, and management of the acute attack.

BACKGROUND: Severe life threatening asthma (SLTA) is important in its own right and as a proxy for asthma death. In order to target hospital based intervention strategies to those most likely to benefit, risk factors for SLTA among those admitted to hospital need to be identified. A case-control study was undertaken to determine whether, in comparison with patients admitted to hospital with acute asthma, those with SLTA have different sociodemographic and clinical characteristics, evidence of inadequate ongoing medical care, barriers to health care, or deficiencies in management of the acute attack. METHODS: Seventy seven patients with SLTA were admitted to an intensive care unit (pH 7.17 (0.15), PaCO(2) 10.7 (5.0) kPa) and 239 matched controls (by date of index attack) with acute asthma were admitted to general medical wards. A questionnaire was administered 24-48 hours after admission. RESULTS: The risk of SLTA in comparison with other patients admitted with acute asthma increased with age (odds ratio (OR) 1.04/year, 95% CI 1.01 to 1.07) and was less for women (OR 0.36, 95% CI 0.20 to 0.68). These variables were controlled for in all subsequent analyses. There were no differences in other sociodemographic features. Cases were more likely to have experienced a previous SLTA (OR 2.04, 95% CI 1.20 to 3.45) and to have had a hospital admission in the last year (OR 1.86, 95% CI 1.09 to 3.18). There were no differences between cases and controls in terms of indicators of quality of ongoing asthma specific medical care, nor was there evidence of disproportionate barriers to health care. During the index attack cases had more severe asthma at the time of presentation, were less likely to have presented to general practitioners, and were more likely to have called an ambulance or presented to an emergency department. In terms of pharmacological management, those with SLTA were more likely to have been using oral theophylline (OR 2.14, 95% CI 1.35 to 3.68) and less likely to have been using inhaled corticosteroids in the two weeks before the index attack (OR 0.69, 95% CI 0.47 to 0.99). While there was no difference in self-management knowledge or behaviour scores, those with SLTA were more likely to have inappropriately used oral corticosteroids during the acute attack (OR 2.09, 95% CI 1.02 to 4.47). CONCLUSIONS: In comparison with those admitted to hospital with acute severe asthma, patients with SLTA were indistinguishable on sociodemographic criteria (apart from male predominance), were more likely to have had a previous SLTA or hospital admission in the previous year, had similar quality ongoing asthma care, had no evidence of increased physical, economic or other barriers to health care, but had demonstrable deficiencies in the management of the acute index attack. Educational interventions, while not losing sight of the need for good quality ongoing care, should focus on providing individual patients with better advice on self-management of acute exacerbations.

Acute Disease↗