Plasma ammonia response to incremental cycling and walking tests in COPD

OBJECTIVE

It is well documented that plasma ammonia accumulates during exercise under conditions of metabolic stress. Metabolic stress (when skeletal muscle ATP supply fails to meet demand) occurs at low work rates during cycling in patients with COPD, but not been described during walking. Walking is an important activity for many patients with COPD and is commonly prescribed in pragmatic outpatient pulmonary rehabilitation programmes. In this study we explored whether metabolic stress occurs during incremental walking at the low work rates these patients achieve.

METHODS

Twenty-nine subjects with stable COPD [mean(SD) age 68(7)years, FEV(1) 50(19)% predicted] performed maximal cardiopulmonary exercise tests on a cycle ergometer and treadmill. Plasma ammonia concentration was measured at rest, 1 and 2min of exercise, peak exercise and 2min recovery.

RESULTS

Subjects achieved mean(SD) cycle work rate of 57(20)W with VO(2max) 15.5(4.6)ml/min per kg, and treadmill distance 284(175)m with VO(2peak) 16.8(4.2)ml/min per kg. Plasma ammonia concentration rose significantly (p<0.001) with walking [mean(SEM) change 24.7(3.8)micromol/l] and cycling [mean(SEM) change 35.2(4.3)micromol/l], but peak exercise ammonia was lower in walking (p<0.01). In a subgroup of subjects (n=7) plasma ammonia did not rise during either cycling or walking despite similar lactate rise and peak exercise indices.

CONCLUSION

Our data indicate that failure of muscle ATP re-synthesis to meet demand and development of metabolic stress can occur during walking in COPD patients at the low work rates these patients achieve. This may therefore be a factor contributing to exercise limitation independent of ventilatory limitation.

Upper critical field, superconducting energy gaps and the Seebeck coefficient in La(0.8)Th(0.2)FeAsO

We report the synthesis and characterization of a new electron-doped La-oxypnictide superconductor by partial substitution of lanthanum by thorium. The superconducting transition temperature at about 30.3 K was observed in La(0.8)Th(0.2)FeAsO, which is the highest in La-based oxypnictide superconductors synthesized at ambient pressure. We find that the decrease in lattice parameters with Th doping in LaOFeAs is more drastic as compared to that obtained by high pressure (6 GPa) synthesis of oxygen-deficient LaOFeAs. The resistivity and magnetic susceptibility measurements yield an upper critical field H(c2)(0) of 47 T. Partial substitution of Th in place of La induces electron doping, as shown by a negative Seebeck coefficient. The temperature-dependent magnetic penetration depth data provides strong evidence for a nodeless low energy gap of 1.4 meV.

Minimum clinically important improvement for the incremental shuttle walking test

BACKGROUND

The incremental shuttle walking test (ISWT) is used to assess exercise capacity in patients with chronic obstructive pulmonary disease (COPD) and is employed as an outcome measure for pulmonary rehabilitation. This study was designed to establish the minimum clinically important difference for the ISWT.

METHODS

372 patients (205 men) performed an ISWT before and after a 7-week outpatient pulmonary rehabilitation programme. After completing the course, subjects were asked to identify, from a 5-point Likert scale, the perceived change in their exercise performance immediately upon completion of the ISWT. The scale ranged from "better" to "worse".

RESULTS

The mean (SD) age was 69.4 (8.4) years, forced expiratory volume in 1 s (FEV(1)) 1.06 (0.53) l and FEV(1)/forced vital capacity (FVC) ratio 50.8 (18.1)%. The baseline shuttle walking test distance was 168.5 (114.6) m which increased to 234.7 (125.3) m after rehabilitation (mean difference 65.9 m (95% CI 58.9 to 72.9)). In subjects who felt their exercise tolerance was "slightly better" the mean improvement was 47.5 m (95% CI 38.6 to 56.5) compared with 78.7 m (95% CI 70.5 to 86.9) in those who reported that their exercise tolerance was "better" and 18.0 m (95% CI 4.5 to 31.5) in those who felt their exercise tolerance was "about the same".

CONCLUSION

Two levels of improvement were identified. The minimum clinically important improvement for the ISWT is 47.5 m. In addition, patients were able to distinguish an additional benefit at 78.7 m.

The plasma ammonia response to cycle exercise in COPD

The plasma ammonia response to exercise in chronic obstructive pulmonary disease (COPD) was examined and the relationship between plasma ammonia concentration and muscle adenine nucleotide metabolism was explored. In total, 25 stable COPD patients and 13 similar-aged controls underwent incremental and constant-work rate cycle exercise tests. Arterialised venous blood was sampled at rest, at 1-min intervals during exercise and <or=5 min after exercise for ammonia and lactate concentration. Peak incremental work rate was significantly less in COPD subjects (67+/-21 W) than similar-aged controls (156+/-46 W). In COPD and control subjects, plasma ammonia concentration increased during incremental exercise until 2 min post-exercise and then declined by 5 min post-exercise. However, two distinct patterns were seen in COPD subjects. In one group (n = 16), ammonia increased (42.8+/-3.3 micromol x L(-1)) by a similar magnitude as the controls (55.5+/-7.0 micromol x L(-1)). In the second COPD group (n = 9), no ammonia increase was observed despite a similar lactate increase. Ammonia change with incremental and constant-work rate exercise strongly correlated in COPD subjects. Plasma ammonia increase correlated with muscle inosine-5'-monophosphate formation after constant-work rate exercise. Plasma ammonia concentration increases during incremental and constant-work rate cycle exercise in chronic obstructive pulmonary disease subjects at lower absolute work rates compared with similar-aged controls. The plasma ammonia response may provide useful information about adenine nucleotide metabolism and, therefore, muscle fatigue during exercise in patients with chronic obstructive pulmonary disease.

Review article: addressing the sexual health of patients with COPD: the needs of the patient and implications for health care professionals

Sexual expression is an important part of our individual identity and yet, this area is rarely addressed by health professionals. This article will explore the possible reasons for this and will also demonstrate the importance of assessing sexuality in patients with chronic obstructive pulmonary disease (COPD).

Osmotic adjustment in chickpea (Cicer arietinum L.) results in no yield benefit under terminal drought

Variation in osmotic adjustment (OA) among chickpea (Cicer arietinum L.) cultivars has been observed when exposed to terminal drought, but some studies suggest that this benefits yield while others suggest it does not benefit yield in water-limited environments. In the present study, parents differing in OA were crossed and a set of advanced breeding lines (ABLs) developed for yield testing. The variation in OA during podding was measured under terminal drought in the F(2), F(3), F(7), and F(8) progeny and in the parents by either rehydrating the leaves before sampling for osmotic potential (OP) or by measuring the relative water content (RWC) and OP on adjacent leaves for the calculation of the OP at full turgor. Yields were measured in the F(8) progeny under terminal drought in Australia and India. While differences in OA were measured in the chickpea lines and parents, OA varied from year to year and did not consistently benefit yield when measured in the field under terminal drought. In Australia, differences in OA were not associated with any yield benefit in any year, while in India early flowering resulted in higher yields at three of the four sites, and OA had an inconsistent effect on seed yields. A comparison of OP at full turgor measured after rehydration and from measurements of RWC and OP showed that the rehydration technique underestimated OA. The lack of contribution of OA to yield of chickpea is discussed.

How long should outpatient pulmonary rehabilitation be? A randomised controlled trial of 4 weeks versus 7 weeks

BACKGROUND

The evidence of benefit for pulmonary rehabilitation (PR) programmes is established. However, the optimal duration of a PR programme is not known. A randomised controlled trial was undertaken in patients with chronic obstructive pulmonary disease (COPD) to assess whether a 4 week PR programme was equivalent to our conventional 7 week PR programme at equivalent time points of 7 weeks and 6 months.

METHODS

One hundred patients (56 men) with stable COPD of mean (SD) age 70 (8) years and forced expiratory volume in 1 second (FEV1) 1.13 (0.50) litres were randomised to either a 7 week (n = 50) or 4 week (n = 50) supervised PR programme. Patients were assessed at baseline, at completion of the supervised PR programme, and 6 months later. Patients randomised to the 4 week group were also assessed at the 7 week time point. Outcome measures were the Incremental Shuttle Walk Test, Endurance Shuttle Walk Test (ESWT), Chronic Respiratory Questionnaire-Self Reported, and the Breathing Problems Questionnaire.

RESULTS

Forty one patients in each group completed the PR programme. Patients made significant within group improvements after supervised rehabilitation. There were no statistically significant differences between the groups for any other measure at the 7 week or 6 month time points, except that patients in the 4 week group attained higher ESWT times (mean difference 124 seconds (95% CI 17.00 to 232.16), p = 0.024) at the 7 week time point.

CONCLUSIONS

A shortened 4 week supervised PR programme is equivalent to a 7 week supervised PR programme at the comparable time points of 7 weeks and 6 months.

A profile of daily activity in chronic obstructive pulmonary disease

BACKGROUND

Little information exists about the pattern of daily activity in patients with chronic obstructive pulmonary disease (COPD), especially in those who are on long-term oxygen therapy (LTOT). The aim of this study was to explore the regular level of domestic physical activity in patients with COPD and to explore differences in activity in those on LTOT.

METHODS

Daily activity was recorded using an activity monitor for 7 consecutive days in 4 groups. Group 1 had severe COPD (FEV1 0.66 [0.42] L) receiving LTOT (n = 9). Group 2 had severe COPD (FEV1 1.07 [0.43] L) and had full knowledge of the activity monitor and the purpose of the study (n = 10). Group 3 had severe COPD (FEV1 1.16 [0.27] L) but were unaware of the precise nature of the study (n = 10). Group 4 (n = 10) were the healthy control group. Participants also completed health status questionnaires.

RESULTS

There were statistically significant differences in the level of daily activity between all groups (P < .001) except between groups 2 and 3. There were no significant differences between days within groups. The activity counts compared to the healthy groups were reduced by 49% in groups 2 and 3 and by 79% in those on LTOT.

CONCLUSION

Patients with COPD demonstrate reduced levels of spontaneous physical activity compared with healthy controls. Furthermore, patients receiving LTOT have an even lower level of domestic activity compared with that of those not on LTOT but with COPD of similar severity.

Adenine nucleotide loss in the skeletal muscles during exercise in chronic obstructive pulmonary disease

BACKGROUND

Skeletal muscle adenine nucleotide loss has been associated with fatigue during high intensity exercise in healthy subjects but has not been studied in patients with chronic obstructive pulmonary disease (COPD). Changes in adenine nucleotides and other metabolites in the skeletal muscles were measured in patients with COPD and age matched healthy volunteers by obtaining biopsy samples from the quadriceps muscle at rest and following a standardised exercise challenge.

METHODS

Eighteen patients with COPD (mean (SD) forced expiratory volume in 1 second 38.1 (16.8)%) and eight age matched healthy controls were studied. Biopsy samples were taken from the vastus lateralis muscle at rest and immediately after a 5 minute constant workload cycle test performed at 80% peak work achieved during a maximal incremental cycle test performed previously.

RESULTS

The absolute workload at which exercise was performed was substantially lower in the COPD group than in the controls (56.7 (15.9) W v 143.2 (26.3) W, p<0.01). Despite this, there was a significant loss of adenosine triphosphate (mean change 4.3 (95% CI -7.0 to -1.6), p<0.01) and accumulation of inosine monophosphate (2.03 (95% CI 0.64 to 3.42), p<0.01) during exercise in the COPD group that was similar to the control group (-4.8 (95% CI -9.7 to 0.08), p = 0.053 and 1.6 (95% CI 0.42 to 2.79), p<0.01, respectively).

CONCLUSIONS

These findings indicate that the ATP demands of exercise were not met by resynthesis from oxidative and non-oxidative sources. This suggests that significant metabolic stress occurs in the skeletal muscles of COPD patients during whole body exercise at low absolute workloads similar to those required for activities of daily living.

Mortality due to constipation and short-segment Hirschsprung's disease

We report a case of mortality secondary to constipation. A 12-year-old child with a history of constipation from the age of 9 years presented in moribund condition with intestinal obstruction secondary to idiopathic constipation. He underwent laparotomy and died within 24 h of operation. At postmortem there was no evidence of abnormalities of the enteric nervous system. A 2nd case of early neonatal death from Hirschsprung's disease is presented to demonstrate that short-segment aganglionosis can be detected at postmortem. Enterocolitis can rapidly progress and be fatal in short-segment Hirschsprung's disease.

Small bowel volvulus due to giant mesenteric lipoma

We report on a 14-year-old girl with acute intestinal obstruction due to volvulus of the small bowel caused by a giant mesenteric lipoma. To the best of our knowledge, this presentation of a mesenteric lipoma is unknown in the previous paediatric literature.

Nutritional enhancement of exercise performance in chronic obstructive pulmonary disease: a randomised controlled trial

BACKGROUND

Pulmonary rehabilitation is effective in improving exercise performance and health status in chronic obstructive pulmonary disease (COPD). However, the role of nutritional support in the enhancement of the benefits of exercise training has not been explored. A double blind, randomised, controlled trial of carbohydrate supplementation was undertaken in patients attending outpatient pulmonary rehabilitation.

METHODS

85 patients with COPD were randomised to receive a 570 kcal carbohydrate rich supplement or a non-nutritive placebo daily for the duration of a 7 week outpatient pulmonary rehabilitation programme. Primary outcome measures were peak and submaximal exercise performance using the shuttle walk tests. Changes in health status, body composition, muscle strength, and dietary macronutrient intake were also measured.

RESULTS

Patients in both the supplement and placebo groups increased shuttle walking performance and health status significantly. There was no statistically significant difference between treatment groups in these outcomes. Patients receiving placebo lost weight whereas supplemented patients gained weight. In well nourished patients (BMI >19 kg/m(2)) improvement in incremental shuttle performance was significantly greater in the supplemented group (mean difference between groups: 27 (95% CI 1 to 53) m, p<0.05). Increases in incremental shuttle performance correlated with increases in total carbohydrate intake.

CONCLUSIONS

When universally prescribed, carbohydrate supplementation does not enhance the rehabilitation of patients with COPD. This study suggests that exercise training results in negative energy balance that can be overcome by supplementation and that, in selected patients, this may improve the outcome of training. The finding of benefit in well nourished patients may suggest a role for nutritional supplementation beyond the treatment of weight loss in COPD.

Health status measurement: sensitivity of the self-reported Chronic Respiratory Questionnaire (CRQ-SR) in pulmonary rehabilitation

BACKGROUND

A self-reported CRQ (CRQ-SR) has recently been developed and found to be a reproducible and reliable measure of health status. This study explores both the sensitivity of the CRQ-SR and relative sensitivity compared with the conventional interviewer led CRQ (CRQ-IL) in patients undergoing pulmonary rehabilitation.

METHODS

Eighty patients with stable chronic obstructive pulmonary disease who had been referred for pulmonary rehabilitation completed the CRQ-SR at initial assessment and at the end of the 7 week programme. A further 35 patients completed both the CRQ-SR and the CRQ-IL, administered 1 week apart, before starting rehabilitation and again at the end of the programme.

RESULTS

There were large statistically and clinically significant changes in mean score per dimension following rehabilitation in all dimensions of the CRQ-SR (dyspnoea mean difference 0.87 (95% CI 0.61 to 1.14); fatigue 0.76 (0.53 to 1.0); emotion 0.60 (0.35 to 0.86); mastery 0.76 (0.52 to 1.0); p<0.001). Similar results were found in the comparison of the sensitivity of the CRQ-SR and the CRQ-IL, with large changes in mean score per dimension following rehabilitation for both versions of the questionnaire (p<0.005). No significant differences were seen in the magnitude of change between the two formats of the questionnaire (p>0.05).

CONCLUSION

The self-reported CRQ is as sensitive to change as the interviewer led CRQ in patients undergoing pulmonary rehabilitation but has the advantage of being less time consuming to administer.

Gastroschisis: determinants of neonatal outcome

This retrospective study elicits information regarding the dependence of neonatal outcome in gastroschisis upon: (1) the mode of delivery, (2) place of birth, (3) time for birth to surgery, (4) method of closure, (5) time from operation to commencement of first enteral feeds. The neonatal intensive care database from five major tertiary centres was used to identify 181 neonates with gastroschisis from 1990 to 2000. There were 8 deaths. There were no significant differences in outcome for infants delivered vaginally (102) versus Caesarean section (79), those born near the tertiary centre (133) as compared to infants born away (48), ones operated within 7 hours (125) compared with those operated after 7 hours (56), with delayed closure (30) versus primary closure (151). Neonates fed within 10 days of operation (85) had significantly lower incidence of sepsis, duration of TPN and hospital stay when compared to those fed after 10 days (96). Early commencement of feeds decreases the incidence of sepsis, duration of total parenteral nutrition (TPN) and hospital stay. Place of delivery, mode of delivery, time to surgery and type of closure do not influence neonatal outcome.

Hirschsprung's disease: the Australian Paediatric Surveillance Unit's experience

Hirschsprung's disease (HD) was introduced into the Australian Paediatric Surveillance Unit (APSU) system in 1996 with the objective to collect data on demographics, incidence, family history, associated anomalies, clinical features, investigation, and surgical treatment in Australia. Children under 15 years of age with HD (confirmed by biopsy) were entered into a database maintained at The Children's Hospital at Westmead in Sydney. Nationwide, 127 children with HD were reported from January 1997 to December 2000, and near-complete information was available on 126. Neonatal presentation was seen in 114 cases (90%), whereas 12 (10%) presented post-neonatally. There was a history of delayed passage of meconium (more than 24 h) in 65 of the 114 patients (57%) who presented in the neonatal period. In those presenting post-neonatally there was no history of delayed passage of meconium. Primary pull-through was performed in 42 of the 82 patients (51%) operated upon. The Soave procedure was performed in 53 of the total 82 (65%) operations and 29 of 42(69%) primary pull-through operations. Pre-operative enterocolitis was seen in 15 of 126 (12%) and postoperative enterocolitis in 17 of 82 (21%) children. The majority of children with HD are diagnosed in the neonatal period (90%). Primary pull-through is becoming more popular (51%). The Soave procedure is the most commonly performed operation (65%) in Australia. Pre- and post-operative enterocolitis is still a significant problem.

Development of a symptom specific health status measure for patients with chronic cough: Leicester Cough Questionnaire (LCQ)

BACKGROUND

Chronic cough is a common condition which has a significant impact on quality of life. Assessment and management are hampered by the absence of well validated outcome measures. The development and validation of the Leicester Cough Questionnaire (LCQ), a self-completed health related quality of life measure of chronic cough, is presented.

METHODS

Patients with chronic cough were recruited from outpatient clinics. The development of the LCQ consisted of three phases: phase 1 (item generation); phase 2 (item reduction, allocation of items to domains and validation of questionnaire); phase 3 (repeatability and responsiveness testing of final version of questionnaire).

RESULTS

Phase 1: Literature review, multidisciplinary team meeting and 15 structured interviews with chronic cough patients generated 44 items (LCQ1) with a 7 point Likert response scale. Phase 2: 104 chronic cough outpatients completed the LCQ1 along with an importance rating for each item. The clinical impact factor method was used for item reduction to 19 items (LCQ2: final version). These items were divided into three domains (physical, psychological and social) following expert opinion. Internal reliability, as assessed using Cronbach's alpha coefficients, varied between 0.79 and 0.89. Concurrent validity was high when the LCQ2 (n=56) was compared with a cough visual analogue score (r=-0.72). There was a moderate relationship with response to the St George's Respiratory Questionnaire (r=-0.54) and SF36 total score (r=0.46). Phase 3: Two week repeatability (n=24) was high with intraclass correlation coefficients for domains varying between 0.88 and 0.96. Responsiveness in nine patients whose cough was successfully treated varied within domains from an effect size of 0.84 to 1.75.

CONCLUSION

The LCQ is a valid, repeatable 19 item self-completed quality of life measure of chronic cough which is responsive to change. It should be a useful tool in clinical trials and longitudinal studies.

Lung volume reduction surgery – a comparison of the long term outcome of unilateral vs. bilateral approaches

OBJECTIVE

Bilateral lung volume reduction surgery (LVRS) is thought to be preferable to unilateral surgery due to greater initial benefit but the subsequent rate of decline may also be greater. We compared the long term physiological and health status outcome of LVRS performed on one or simultaneously on both lungs.

METHODS

Prospective data were collected on a consecutive series of 65 patients undergoing LVRS who were all suitable for bilateral surgery. Twenty-six patients: age 59 (8) years underwent bilateral LVRS by video-assisted thoracoscopy (VAT) or sternotomy and 39 patients: age 60 (6) years underwent unilateral VAT. The perioperative effects of LVRS on spirometry were prospectively recorded at 3, 6, 12 and 24 months.

RESULTS

The unilateral group had similar preoperative lung volumes to the bilateral patients: forced expiratory volume in 1s (FEV(1)) 26 vs. 30% predicted, RV 275 vs. 246% predicted and total lung capacity (TLC) 148 vs. 142% predicted. Unilateral LVRS was associated with significantly lower weight of lung resected: 80 (31) vs. 118 (46) g; hospital stay: 16 (10) days vs. 28 (22) days. Thirty-day mortality was 3% in the unilateral and 8% in the bilateral group (P=0.34). Postoperative ventilation occurred in 5% in the unilateral and in 42% in the bilateral group (P=0.0002). The decline of FEV(1) during the first postoperative year was significant in the bilateral group (-313 ml/y, P=0.04) but not significant in the unilateral group (-50 ml/y, P=0.18). SF 36 scores in all eight domains were similar in both groups preoperatively and at any postoperative interval.

CONCLUSION

We have found no benefit from bilateral simultaneous LVRS and prefer unilateral LVRS because of the lower morbidity, resulting in earlier discharge, and slower decline in physiological benefit.

Duodenal atresia with vascular rings and subglottic stenosis

This case report of duodenal atresia associated with a vascular ring and subglottic stenosis raises some interesting issues of management.

Bedside methods versus dual energy X-ray absorptiometry for body composition measurement in COPD

The measurement of body composition is of value in the nutritional assessment of patients with chronic obstructive pulmonary disease (COPD). The purpose of the present study was to compare two bedside methods for the measurement of body composition using dual energy X-ray absorptiometry (DEXA) as a reference method. Fat-free mass (FFM) was measured using DEXA, bioelectric impedance analysis (BIA) and skinfold anthropometry (SFA) in a cohort of 85 COPD patients accepted for pulmonary rehabilitation. Patients whose body mass index was >30 were excluded. Relative to DEXA, BIA underestimated FFM, whereas it was overestimated by SFA. There was a systematic increase in bias with mean FFM for both DEXA versus BIA and DEXA versus SFA, but this was almost eliminated when results were expressed as FFM index. Significant sex differences in the bias of BIA and SFA measurements of FFM were found. Forty-two (49.4%) patients were identified as nutritionally depleted using DEXA. Compared to DEXA, the sensitivity for detecting nutritional depletion was 86 and 74% for BIA and SFA, respectively, and the specificity 88 and 98%, respectively. There are significant intermethod differences in the measurement of body composition in chronic obstructive pulmonary disease patients. The choice of measurement method will have implications for nutritional assessment in chronic obstructive pulmonary disease.

Excision duodenoplasty: a new technique for congenital duodenal obstruction

Slow anastomotic function is a common problem in the management of congenital duodenal obstruction. We describe a simple technique of excision duodenoplasty (ED) that results in a fixed open anastomosis, which facilitates early commencement of feeds and discharge from hospital. A retrospective case-note review (1981-2000) was undertaken to compare the results of ED with side-to-side duodenoplasty (SSD) and diamond-shaped anastomosis (DD). The outcome measures were days to commencement of feeds, duration of total parenteral nutrition (TPN), and length of hospital stay. In ED a 1.0 to 1.5-cm elliptical segment of dilated duodenum is excised. A longitudinal incision is made in the smaller distal duodenum. A side-to-side one-layer anastomosis is performed. The wall of the proximal duodenal stump is thick, and excision of the ellipse keeps the anastomosis open by preventing apposition of the opposing walls. This facilitates good drainage across the anastomosis. The time to onset of feeding was longer after SSD (median 7 days) compared to ED (5 days) and DD (5 days). The total duration of TPN was also longer for SSD (9 days) in comparison to ED (7 days) and DD (7 days). Although the duration of hospital stay was more for SSD (18 days) than ED (13 days) and DD (16 days), this difference was not statistically significant. The ED technique thus gives an equally good result as DD and a better result than SSD. It is simple to perform and to teach.

How to test the safety of homemade antegrade colonic washout fluid?

Normal saline is commonly used for antegrade colonic washout enemas. The saline solution is usually made at home by adding measured quantities of common salt to tap water. The best method for the carers to check the concentration of salt in these homemade solutions has not been reported. Various concentrations of saline solutions were tested for specific gravity (SG) with an aquarium hygrometer and urine analysis sticks by two blinded independent observers. An aquarium hygrometer can read SG with an accuracy of 0.00046 for saline solutions made in tap water and 0.00051 for those made with sterile water. Urine analysis dipsticks sticks failed to achieve this accuracy. An aquarium hygrometer is a simple and reliable way to measure the SG of homemade saline solutions. Its use may avoid the problems associated with over- or under-concentration of salt in the antegrade enema solution.

The incremental shuttle walking test in elderly people with chronic airflow limitation

BACKGROUND

There is a concern that comorbidity or frailty in older people could limit the usefulness of currently available exercise tests for chronic lung disease. This study evaluated the feasibility and reproducibility of the incremental shuttle walking test (SWT) in people aged 70 years or over, compared exercise tolerance with other disability markers, and assessed whether the SWT is responsive to change after bronchodilators.

METHODS

Fifty elderly patients with chronic airflow limitation (CAL) and 32 controls without airflow limitation attempted the SWT before and after combined nebulised salbutamol/ipratropium bromide. Subjects also completed the Nottingham Extended Activities of Daily Living index (NEADL) and the London Handicap score (LHS).

RESULTS

Forty four subjects with CAL (88%) and 29 controls (84%) completed the SWT, including many with co-morbidities. Two week repeatability was good and the SWT was strongly associated with EADL (r=0.51, p<0.001) and LHS (r=0.43, p<0.004), but only weakly with forced expiratory volume in 1 second (FEV1) (r=0.31, p=0.05). Subjects with CAL walked a mean distance of 177.7 m compared with 243.3 m in controls (p<0.001); following bronchodilator therapy the distance walked increased in the CAL group by 13.2% (p=0.009).

CONCLUSION

The SWT is a feasible and reproducible measure of exercise tolerance in elderly people with and without airflow obstruction and correlates with other markers of disability. It is sensitive to change following bronchodilation in subjects with CAL, although the change correlates less well with improvements in FEV1. Overall, these results suggest that the SWT might be an appropriate measure to assess interventions in elderly people.

Development of a self-reported Chronic Respiratory Questionnaire (CRQ-SR)

BACKGROUND

The Chronic Respiratory Questionnaire (CRQ) is an established measure of health status for chronic obstructive pulmonary disease (COPD). It has been found to be reproducible and sensitive to change, but as an interviewer led questionnaire is very time consuming to administer. A study was undertaken to develop a self-reported version of the CRQ (CRQ-SR) and to compare the results of this questionnaire with the conventional interviewer led CRQ (CRQ-IL).

METHODS

Fifty two patients with moderate to severe COPD participated in the study. Subjects completed the CRQ-SR 1 week after completing the CRQ-IL, and a further CRQ-SR was administered 1 week later. For patients in group A (n=27) the dyspnoea provoking activities that they had previously selected were transcribed onto the second CRQ-SR, while patients in group B (n=25) were not informed of their previous dyspnoea provoking activities when they completed the second CRQ-SR. To assess the short term reproducibility and reliability of the CRQ-SR it was then administered twice at an interval of 7-10 days to a further group of 21 patients. The CRQ-IL was not administered. Longer term reproducibility was examined in 39 stable patients who completed the CRQ-SR at initial assessment and then again 7 weeks later.

RESULTS

Mean scores per dimension, mean differences, and limits of agreement are given for each dimension in the comparison of the two questionnaires. There were no statistically significant differences between the CRQ-IL and CRQ-SR in the mastery and fatigue dimensions (p>0.05). A statistically significant difference between the two scores was found in the dyspnoea dimension (p=0.006) and the emotional function dimension (p=0.04), but these differences were well within the minimum clinically important threshold. No statistically significant difference in the mean dyspnoea score was seen between groups A and B. The CRQ-SR was found to be reproducible both in the short term and after the longer period of 7 weeks, with no statistically or clinically significant differences in any dimension. Test-retest reliability was found to be high in each dimension, both in the short and longer term.

CONCLUSIONS

The CRQ-SR is a reproducible, reliable, and stable measure of health status. It compares well with the CRQ-IL but cannot be used interchangeably. The main advantage of the CRQ-SR over the CRQ-IL is that is quick to administer, reducing assessment time and hence cost.