Korst RJ; Ginsberg RJ; Ailawadi M; Bains MS; Downey RJ Jr; Rusch VW; Stover D
Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
Ann Thorac Surg (United States) Sep 1998, 66 (3) p898-902

BACKGROUND: Patients often undergo limited resection instead of lobectomy for non-small cell lung cancer because of a low preoperative forced expiratory volume in 1 second (FEV1). Our goal is to define criteria that will preoperatively identify a group of patients who will not lose further function after lobectomy.

METHODS: Patients who underwent lobectomy with a preoperative FEV1 of less than 80% of predicted were retrospectively identified. Data collected included preoperative and postoperative pulmonary function tests, age, sex, the lobe resected, and preoperative ventilation-perfusion scan result.

RESULTS: Thirty-two patients were included in this study. The median preoperative FEV1 was 60% of predicted (1.65 L) and the mean change in FEV1 was a loss of 7.8% after lobectomy. The patients were divided into two groups. Group 1 (n = 13) had a preoperative FEV1 of less than or equal to 60% of predicted (median, 49%; 1.35 L) combined with an FEV1 to forced vital capacity ratio of less than or equal to 0.6. Group 2 (n = 19) includes all other patients (median preoperative FEV1, 69% of predicted; 1.87 L). The mean changes in FEV1 after lobectomy were +3.7% and -15.7% for groups 1 and 2, respectively (p < 0.005). A chronic obstructive pulmonary disease index was defined and then calculated for each patient. The relationship between this index and the change in FEV1 after lobectomy for all 32 patients appears linear (r = -0.43; p = 0.015).

CONCLUSIONS: Patients with a very low preoperative FEV1 and FEV1 to forced vital capacity ratio are less likely to lose ventilatory function after lobectomy and may actually improve it.

Del Rizzo DF; Boyd WD; Novick RJ; McKenzie FN; Desai ND; Menkis AH
London Health Sciences Centre, University of Western Ontario, Canada.
ddelrizzo@exchange.hsc.mb.ca
Ann Thorac Surg (United States) Sep 1998, 66 (3) p1002-7

BACKGROUND: Myocardial revascularization without cardiopulmonary bypass has been proposed as a potential therapeutic alternative in high-risk patients undergoing coronary artery bypass grafting. To evaluate this possibility we compared 15 high-risk (HR) patients in whom minimally invasive direct coronary artery bypass grafting was used as the method of revascularization with 41 consecutive patients who underwent conventional coronary artery bypass grafting during 1 month.

METHODS: Patients undergoing myocardial revascularization without cardiopulmonary bypass were significantly older than their low-risk (LR) counterparts (72.2 +/- 11.6 versus 63.3 +/- 9.7 years, p = 0.006). The demographic profile for HR versus LR patients was as follows: female patients, 60.0% versus 26.8%, p = 0.02; diabetes, 20.0% versus 24.4%, p = 0.7; prior stroke, 33.3% versus 7.4%, p = 0.03; chronic obstructive pulmonary disease, 60.0% versus 9.8%, p < 0.0001; peripheral vascular disease, 33.3% versus 12.2%, p = 0.03, congestive heart failure, 26.6% versus 9.8%, p = 0.09; impaired left ventricular (ejection fraction < 0.40), 40.0% versus 17.0%, p = 0.07; urgent operation, 86.6% versus 46.3%, p < 0.0001; and redo operation, 20.0% versus 0%, p = 0.003.

RESULTS: There were no deaths in the HR group and one death in the LR group. The average intensive care unit stay was 1.1 +/- 0.5 days in HR patients versus 1.6 +/- 1.6 days in LR individuals (p = 0.2), and the average hospital stay was 6.1 +/- 1.8 versus 7.3 +/- 4.4 days, respectively (p = 0.3). We used an acuity risk score index developed by the Adult Cardiac Care Network of Ontario to predict outcome in the HR group. The expected intensive care unit stay in HR patients was 4.1 +/- 1.2 days (versus the observed stay of 1.1 +/- 0.5 days, p < 0.0001), and the expected hospital stay was 12.5 +/- 1.5 days (versus the observed stay of 6.1 +/- 1.8 days, p < 0.0001). The expected mortality in the HR group was 6.1% versus 0%, p = 0.3. A cost regression model was used to examine predicted versus actual cost (in Canadian dollars) for the HR patient cohort (based on Ontario Ministry of Health funding). The expected cost for the HR cohort would have been $11,997 per patient. In contrast, the average cost for these 15 patients was $5,997 per patient, an estimated cost saving of 50%.

CONCLUSIONS: Myocardial revascularization without cardiopulmonary bypass appears to be a safe and cost-effective therapeutic modality for HR patients requiring myocardial revascularization.

Poole PJ; Brodie SM; Stewart JM; Black PN
Department of Medicine, Faculty of Medicine and Health Sciences, University of Auckland, NZ.
Aust N Z J Med (Australia) Jun 1998, 28 (3) p322-6

BACKGROUND: There is anecdotal evidence that nebulised saline relieves breathlessness at rest in patients with severe chronic obstructive pulmonary disease (COPD). It is unclear whether nebulised beta agonists are any more effective than nebulised saline in relieving breathlessness at rest in these individuals. AIM: To compare the effects of nebulised saline and nebulised terbutaline on breathlessness at rest in patients with severe COPD.

METHODS: We studied 18 patients with severe COPD with a mean age of 71.1 years, forced expiratory volume in 1 second (FEV1) of 0.58 L and vital capacity (VC) of 1.59 L, in a randomised, double-blind, crossover trial. The subjects received three doses of nebulised saline on one study day, and three doses of nebulised terbutaline (cumulative dose 10 mg) on the other. Breathlessness was measured using Likert and Visual Analogue Scales (VAS).

RESULTS: Both treatments led to a significant improvement in breathlessness on VAS and Likert scales but there was no significant difference in breathlessness scores for saline compared with terbutaline. There was a small but significant increase in FEV1 with terbutaline of 74 mL, but no change with saline.

CONCLUSIONS: A saline aerosol has no effect on lung function but reduces breathlessness at rest in subjects with severe COPD. Nebulised saline may be considered as an adjunct to the use of nebulised bronchodilators for the treatment of breathlessness in patients with COPD.

Tsukino M; Nishimura K; Ikeda A; Hajiro T; Koyama H; Izumi T
Chest Disease Research Institute, Kyoto University, Japan.
Thorax (England) Apr 1998, 53 (4) p269-73

BACKGROUND: The effects of theophylline or anticholinergic agents on exercise capacity in patients with chronic obstructive pulmonary disease (COPD) remain controversial. The aim of the present study was to compare the effect of an oral theophylline with an inhaled anticholinergic agent and to examine the effects of combined therapy on exercise performance using progressive cycle ergometry.

METHODS: Twenty one men with stable COPD and a mean (SD) forced expiratory volume in one second (FEV1) of 1.00 (0.40) 1 were studied. Theophylline (600 or 800 mg daily), ipratropium bromide (160 micrograms), a combination of both drugs, and placebo were given in a randomised, double blind, four period crossover design study. Spirometric data, pulse rate, and blood pressure were assessed before and at 90 and 120 minutes after inhalation. Symptom limited progressive cycle ergometer exercise tests (20 watts/min) were performed 90 minutes after each inhalation, and dyspnoea was measured during exercise using the Borg scale.

RESULTS: The mean (SD) serum theophylline concentration was 18.3 (6.3) micrograms/ml, and seven patients had side effects during treatment with theophylline. Theophylline and ipratropium bromide produced greater increases in FEV1, maximal oxygen consumption, maximal minute ventilation, and several dyspnoea ratios than placebo. There were no differences between theophylline and ipratropium bromide except in maximal heart rate. A combination of both drugs produced greater improvements in pulmonary function and exercise capacity than either drug alone.

CONCLUSIONS: Both high dose theophylline and high dose ipratropium bromide improved exercise capacity in patients with stable COPD. Although data based on short term effects cannot be directly applied to long term therapy, theophylline added to an inhaled anticholinergic agent may have beneficial effects on exercise capacity in patients with COPD.

Murata GH; Kapsner CO; Lium DJ; Busby HK
Veterans Affairs Medical Center, and the Department of Medicine, University of New Mexico School of Medicine, Albuquerque 87108, USA.
J Gen Intern Med (United States) Jul 1998, 13 (7) p462-8

OBJECTIVE: To develop and validate a multivariate model for predicting respiratory status in patients with advanced chronic obstructive pulmonary disease (COPD).

DESIGN: Prospective, double-blind study of peak flow monitoring.

SETTING: Albuquerque Veterans Affairs Medical Center.

PATIENTS: Male veterans with an irreversible component of airflow obstruction on baseline pulmonary function tests.

MEASUREMENTS: This study was conducted between January 1995 and May 1996. At entry, subjects were instructed in the use of the modified Medical Research Council Dyspnea Scale and a mini-Wright peak flow meter equipped with electronic storage. For the next 6 months, they recorded their dyspnea scores once daily and peak expiratory flow rates twice daily, before and after the use of bronchodilators. Patients were blinded to their peak expiratory flow rates, and medical care was provided in the customary manner. Readings were aggregated into 7-day sampling intervals, and interval means were calculated for dyspnea score and peak expiratory flow rate parameters. Intervals from all subjects were then pooled and randomized to separate groups for model development (training set) and validation (test set). In the training set, logistic regression was used to identify variables that predicted future respiratory status. The dependent variable was the log odds that the subject would attain his highest level of dyspnea in the next 7 days. The final model was used to stratify the test set into "high-risk" and "low-risk" categories. The analysis was repeated for 3-day intervals.

MAIN RESULTS: Of the 40 patients considered eligible for study, 8 declined to participate, 4 could not master the technique of peak flow monitoring, and 6 had no fluctuations in their dyspnea level. The remaining 22 subjects form the basis of this report. Fourteen (64%) of the latter completed the 6-month protocol. Data from the 8 who were dropped or died were included up to the point of withdrawal. For 7-day forecasts, mean dyspnea score and mean daily prebronchodilator peak expiratory flow rate were identified as predictor variables. The adjusted odds ratio (OR) for mean dyspnea score was 2.71 (95% confidence interval [CI] 1.79, 4.12) per unit. For mean prebronchodilator peak expiratory flow rate, it was 1.05 (95% CI 1.01, 1.09) per percentage predicted. For 3-day forecasts, the model was composed of mean dyspnea score and mean daily bronchodilator response. The ORs for these terms were 2.66 (95% CI 2.06, 3.44) per unit and 0.980 (95% CI 0.962, 0.998) per percentage of improvement over baseline, respectively. For a given level of dyspnea, higher pre-bronchodilator peak expiratory flow rate and lower bronchodilator response were poor prognostic findings. When the models were applied to the test sets, "high-risk" intervals were 4 times more likely to be followed by maximal symptoms than "low-risk" intervals.

CONCLUSIONS: Dyspnea scores and certain peak expiratory flow rate parameters are independent predictors of respiratory status in patients with COPD. However, our results suggest that monitoring is of little benefit except in patients with the most advanced form of this disease, and its contribution to their management is modest at best.

Brown JS; Meecham Jones DJ; Mikelsons C; Paul EA; Wedzicha JA
Department of Respiratory Medicine, London Chest Hospital.
J R Coll Physicians Lond (England) May-Jun 1998, 32 (3) p219-24

OBJECTIVES: To assess the use of nasal intermittent positive pressure ventilation (NIPPV) in treating acute-on-chronic respiratory failure in a general medical ward.

DESIGN: Retrospective analysis of clinical outcome.

SETTING: A general medical ward of a tertiary respiratory medicine referral centre.

SUBJECTS: Altogether 75 patients admitted with acute exacerbations of chronic respiratory failure and treated NIPPV.

MAIN OUTCOME MEASURES: Blood gas tensions determined at admission to hospital and during NIPPV, tolerance of NIPPV and mortality.

RESULTS: During treatment with NIPPV, the mean (SD) PaO2 increased rapidly by 2.31 (3.58) kPa (p < 0.0001), while the mean PaCO2 fell by 1.07 (1.74) kPa (p < 0.0001) and the mean pH increased by 0.03 (0.07) (p = 0.001). Altogether 57 (76%) of patients tolerated NIPPV, and (9.3%) died in hospital. Improvement in PaO2 was more noticeable in patients with chronic obstructive pulmonary disease (+3.13 (3.49) kPa, p < 0.0001) than in those with restrictive chest wall disease (+1.20 (3.07) kPa, p = 0.25) or obstructive sleep apnoea (+0.18 (3.64), p = 0.88). The reduction in PaCO2 was similar in all three groups.

CONCLUSIONS: In routine treatment of unselected patients with acute-on-chronic respiratory failure who are being cared for on a general ward, NIPPV rapidly improves hypoxaemia and hypercapnia, is well tolerated and is associated with low mortality.

Wrigge H; Sydow M; Zinserling J; Neumann P; Hinz J; Burchardi H
Zentrum Anaesthesiologie, Rettungs- u. Intensivmedizin, Gottingen, Germany.
hwrigge@gwdg.de
Intensive Care Med (United States) May 1998, 24 (5) p487-93

OBJECTIVE: Validation of an open-circuit multibreath nitrogen washout technique (MBNW) for measurement of functional residual capacity (FRC). The accuracy of FRC measurement with and without continuous viscosity correction of mass spectrometer delay time (TD) relative to gas flow signal and the influence of baseline FIO2 was investigated.

DESIGN: Laboratory study and measurements in mechanically ventilated patients.

SETTING: Experimental laboratory and anesthesiological intensive care unit of a university hospital.

PATIENTS: 16 postoperative patients with normal pulmonary function (NORM), 8 patients with acute lung injury (ALI) and 6 patients with chronic obstructive pulmonary disease (COPD) were included.

INTERVENTIONS: Change of FIO2 from baseline to 1.0.

MEASUREMENTS AND MAIN RESULTS: FRC was determined by MBNW using continuous viscosity correction of TD(TDdyn), a constant TD based on the viscosity of a calibration gas mixture (TD0) and a constant TD referring to the mean viscosity between onset and end of MBNW (TDmean). Using TDdyn, the mean deviation between 15 measurements of three different lung model FRCs (FRCmeasured) and absolute volumes (FRCmodel) was 0.2%. For baseline FIO2 ranging from 0.21 to 0.8, the mean deviation between FRCmeasured and FRCmodel was -0.8%. However, depending on baseline FIO2, the calculation of FRC using TDmean and TD0 increased the mean deviation between FRCmeasured and FRCmodel to 2-4% and 8-12%, respectively. In patients (n = 30) the average repeatability coefficient was 6.0%. FRC determinations with TDmean and TD0 were 0.8-13.3% and 4.2-23.9% (median 2.7% and 8.7%) smaller than those calculated with TDdyn.

CONCLUSION: A dynamic viscosity correction of TD improves the accuracy of FRC determinations by MBNW considerably, when gas concentrations are measured in a sidestream. If dynamic TD correction cannot be performed, the use of constant TDmean might be suitable. However, in patient measurements this can cause an FRC underestimation of up to 13%.

Klein JJ; van der Palen J; Seydel ER; Kerkhoff AH
Medisch Spectrum Twente, afd. Longziekten, Enschede.
Ned Tijdschr Geneeskd (Netherlands) Mar 28 1998, 142 (13) p711-5

OBJECTIVE: To assess the knowledge of adult asthmatics about medication for self-treatment.

DESIGN: Descriptive.

SETTING: Department of Pulmonary Diseases, Medisch Spectrum Twente, Enschede, the Netherlands.

METHODS: As a part of a larger project aimed at improvement of self-management and self-treatment, all adults aged 18-65 years in Enschede (population 146,000) reported by the city pharmacists as using medication for asthma or chronic obstructive pulmonary disease, in 1994 were sent a questionnaire including 7 items pertaining to knowledge about lung medication. From among those who failed to respond after a written reminder and an appeal in local papers, a random group of 9% were interviewed by telephone. Of the responders who reported that according to their GPs they had asthma and who had answered the questions on medication, the number of questions answered correctly was counted; in addition, the question was investigated whether their level of knowledge was related to sex, education, use of (inhalation) corticosteroids and the form of explanation received.

RESULTS: A total of 4563 questionnaires were sent out: 2259 (50%) usable forms were returned. The responders were better educated than the 192 non-responders interviewed, but did not differ as to age or sex. Of the responders, 1262 (56%) reported that their GPs had told them they had asthma. On average they had answered 2.4 (range: 0-7) out of 7 questions correctly. Previous instruction, number of sources of information, duration of taking medication, use of inhaled steroids, female sex and better education were all positively related with a higher knowledge score in this group.

CONCLUSION: Adult asthmatics did not have sufficient knowledge about their medication. Improving such knowledge should therefore be an important element in the development of a self-management programme.

Boeree MJ; Peters FT; Postma DS; Kleibeuker JH
Dept of Pulmonary Medicine, University Hospital, Groningen, The Netherlands.
Eur Respir J (Denmark) May 1998, 11 (5) p1070-4

Acid gastro-oesophageal reflux may aggravate respiratory symptoms in patients with asthma and chronic obstructive pulmonary disease (COPD) by increasing airway hyperresponsiveness through vagally-mediated pathways. We wanted to determine whether elimination of acid reflux could improve symptoms in such patients. In a randomized, double-blind, placebo-controlled study, 36 allergic and nonallergic subjects (17 males and 19 females, mean age 52 yrs), with airway obstruction and severe airway hyperresponsiveness despite maintenance treatment with an inhaled corticosteroid and with increased acid gastro-oesophageal reflux, were treated either with omeprazole, 40 mg b.i.d., or placebo for 3 months. Primary endpoints were: airway hyperresponsiveness, as determined by the provocative concentration of methacholine producing a 20% fall in forced expiratory volume in one second (PC20); and airway obstruction. Secondary endpoints were: peak expiratory flow variability; reversibility to inhaled ipratropium bromide as a parameter of vagal activity; asthma symptoms scores; and medication used. Reflux was measured by 24 h ambulatory intraoesophageal pH measurement. Omeprazole, 40 mg b.i.d., for 3 months had no beneficial effect on any of the pulmonary parameters, despite its profound effect on acid reflux and improvement of reflux symptoms scores, compared to placebo. The results of this study do not support a role for intensive antireflux therapy to improve pulmonary symptoms and function in patients with asthma and chronic obstructive pulmonary disease, who have severe airway hyperresponsiveness despite maintenance treatment with inhaled corticosteroids.

Jones SE; Packham S; Hebden M; Smith AP
Chest Department, Llandough Hospital & Community NHS Trust, Penarth, South Glamorgan, UK.
Thorax (England) Jun 1998, 53 (6) p495-8

BACKGROUND: There is increasing interest in the use of non-invasive nocturnal intermittent positive pressure ventilation (NIPPV) in the management of patients with chronic hypercapnoeic (type II) respiratory failure. Although this treatment enables patients requiring mechanical ventilatory support to the treated more readily at home, few studies have been done to demonstrate its long term benefits in chronic obstructive pulmonary disease (COPD) and the application of NIPPV in these circumstances remains controversial.

METHODS: Eleven patients in severe stable chronic type II respiratory failure due to COPD who were unresponsive to conventional treatments experienced symptomatic hypercapnia when receiving sufficient supplementary oxygen to result in an arterial oxygen saturation (SaO2) of > 90%. They were assessed for treatment with NIPPV, and its effects were observed for over two years using arterial blood gas tensions, spirometric parameters and body mass index (BMI), survival, hospital admissions, use of general practitioner resources, and patient satisfaction.

RESULTS: Hospital admissions and GP consultations were halved after one year compared with the year before NIPPV and there was a sustained improvement in arterial blood gas tensions at 12 and 24 months when breathing air, despite progressive deterioration in ventilatory function. BMI did not change during the period of observation. The median survival was 920 days, with no patient dying within the first 500 days.

CONCLUSIONS: Domiciliary NIPPV results in improvements in arterial blood gas tensions which are sustained after two years of treatment and reduces both hospital admissions and general practitioner visits by patients with severe COPD in hypercapnoeic respiratory failure. It is well tolerated and, although there was no control group, survival appears to be prolonged when these results are compared with those of the NOTT and MRC (LTOT) trials.

Bourbeau J; Rouleau MY; Boucher S
McGill University Health Centre, McGill University, Montreal, Canada.
Thorax (England) Jun 1998, 53 (6) p477-82

BACKGROUND: Inhaled corticosteroids are known to be beneficial for patients with asthma, but their role in treating patients with stable chronic obstructive pulmonary disease (COPD) remains controversial. A study was undertaken to determine whether inhaled corticosteroids are of functional benefit in patients who did not show improvement with a trial of oral corticosteroids.

METHODS: In phase I patients with stable COPD were given a two week course of oral placebo followed by two weeks of prednisone 40 mg per day in a single blind manner to distinguish between responders and non-responders to oral corticosteroids. In phase II a double blind, randomised, parallel group trial of inhaled budesonide 1600 micrograms per day versus placebo was carried out in 79 nonresponders to oral corticosteroids. The primary outcome measure was forced expiratory volume in one second (FEV1), and secondary outcome measures were exercise capacity, dyspnoea with exertion, quality of life, peak expiration flow rate, and respiratory symptoms.

RESULTS: Randomisation allocated 39 subjects to inhaled corticosteroids and 40 to placebo. There was no difference in the change in FEV1 from baseline between the treatment and placebo groups; mean difference -12 ml (95% CI -88 to 63) at three months and -4 ml (95% CI -95 to 87) at six months. The proportion of patients with a 15% or greater improvement was no higher among those receiving inhaled corticosteroids than in the placebo group at any of the follow up visits. Changes in secondary outcomes were also no different.

CONCLUSIONS: Inhaled corticosteroids, even at high doses, were of no physiological or functional benefit in these patients with advanced COPD.

Gottlieb SS; McCarter RJ; Vogel RA
Department of Medicine, University of Maryland School of Medicine, Baltimore, USA.
N Engl J Med (United States) Aug 20 1998, 339 (8) p489-97

BACKGROUND: Long-term administration of beta-adrenergic blockers to patients after myocardial infarction improves survival. However, physicians are reluctant to administer beta-blockers to many patients, such as older patients and those with chronic pulmonary disease, left ventricular dysfunction, or non-Q-wave myocardial infarction.

METHODS: The medical records of 201,752 patients with myocardial infarction were abstracted by the Cooperative Cardiovascular Project, which was sponsored by the Health Care Financing Administration. Using a Cox proportional-hazards model that accounted for multiple factors that might influence survival, we compared mortality among patients treated with beta-blockers with mortality among untreated patients during the two years after myocardial infarction.

RESULTS: A total of 34 percent of the patients received beta-blockers. The percentage was lower among the very elderly, blacks, and patients with the lowest ejection fractions, heart failure, chronic obstructive pulmonary disease, elevated serum creatinine concentrations, or type 1 diabetes mellitus. Nevertheless, mortality was lower in every subgroup of patients treated with beta-blockade than in untreated patients. In patients with myocardial infarction and no other complications, treatment with beta-blockers was associated with a 40 percent reduction in mortality. Mortality was also reduced by 40 percent in patients with non-Q-wave infarction and those with chronic obstructive pulmonary disease . Blacks, patients 80 years old or older, and those with a left ventricular ejection fraction below 20 percent, serum creatinine concentration greater than 1.4 mg per deciliter (124 micromol per liter), or diabetes mellitus had a lower percentage reduction in mortality. Given, however, the higher mortality rates in these subgroups, the absolute reduction in mortality was similar to or greater than that among patients with no specific risk factors.

CONCLUSIONS: After myocardial infarction, patients with conditions that are often considered contraindications to beta-blockade (such as heart failure, pulmonary disease, and older age) and those with nontransmural infarction benefit from beta-blocker therapy.

Nava S
Respiratory Intensive Care Unit, Centro Medico di Montescano, S. Maugeri Foundation, Italy.
Arch Phys Med Rehabil (United States) Jul 1998, 79 (7) p849-54

OBJECTIVE: Pulmonary rehabilitation has been shown to be of benefit to clinically stable patients with chronic obstructive pulmonary disease (COPD). This study examined the effect of pulmonary rehabilitation on some physiologic variables in COPD patients recovering from an episode of acute respiratory failure.

DESIGN: A prospective, randomized study.

SETTING: A respiratory intensive care unit (RICU).

PATIENTS: Eighty COPD patients recovering from an episode of acute respiratory failure were randomized in a 3:1 fashion to receive stepwise pulmonary rehabilitation (group A, n=60 patients) or standard medical therapy (group B, n=20 patients).

MAIN OUTCOME MEASURES: Improvements in exercise tolerance, sense of breathlessness, respiratory muscle function, and pulmonary function test values were measured, respectively, by exercise capacity (6-minute walking distance [6MWD]), dyspnea score (Visual Analog Scale [VAS]), maximal inspiratory pressure (MIP), forced expiratory volume in 1 second (FEV1), and forced vital capacity (FVC).

INTERVENTIONS: Group A received pulmonary rehabilitation that consisted of passive mobilization (step I), early deambulation (step II), respiratory and lower skeletal muscle training (step III), and if the patients were able, complete lower extremity training on a treadmill (step IV). Group B received standard medical therapy plus a basic deambulation program.

RESULTS: Sixty-one of 80 patients were mechanically ventilated at admission to the unit and most of them were bedridden. Twelve of the 60 group A patients and 4 of the 20 group B patients died during their RICU stay, and 9 patients required invasive mechanical ventilation at home after their discharge. The total length of RICU stay was 38+/-14 days for patients in group A versus 33.2+/-11 days for those in group B. Most patients from both groups regained the ability to walk, either unaided or aided. At discharge, 6 MWD results were significantly improved (p < .001) in Group A only. MIP improved in Group A only (p < .05), while VAS scores improved in both groups, but the improvement was more marked in group A (p < .001) than in group B (p < .05).

CONCLUSIONS: COPD patients who were admitted to a RICU in critical condition after an episode of acute respiratory failure and who, in most cases, required mechanical ventilation benefited from comprehensive early pulmonary rehabilitation, compared with patients who received standard medical therapy and progressive ambulation.

Montner P; Sergent M; Case E; Douglas M; Griego E; Martinez F; Jaramillo B; Tarasenko P
Pulmonary Section, Albuquerque Veterans Affairs Medical Center, NM, USA.
Jt Comm J Qual Improv (United States) Apr 1998, 24 (4) p203-11

BACKGROUND: Long-term oxygen therapy (LTOT) is the only treatment demonstrated to prolong the life of patients with chronic obstructive pulmonary disease . In November 1994, a multidisciplinary total quality improvement (TQI) team composed of the involved hospital services was established to reorganize and improve the LTOT program at the Albuquerque Veterans Affairs Medical Center (AVAMC), Albuquerque.

FROM THE OLD TO THE NEW PROCESS: The LTOT team used a process map to analyze the current process and gather information from patients and staff regarding their satisfaction with the program. It then began working on the identified problems and streamlining the LTOT referral process. A respiratory therapy position with the specific responsibility of serving as the home oxygen (O2) coordinator (HOC) was established and filled. The evaluation process was to be initiated by the AVAMC physicians, following which the HOC would perform a newly standardized evaluation that would establish the patient's need for O2 and result in a specific prescription.

RESULTS: Quality indicators were selected to monitor changes in the program. Data from chart reviews, the Veterans Affairs National Cost Containment Center, and patient surveys were used to evaluate the indicators. Timeliness of referral to the program before inpatient discharge improved, O2 prescriptions in the new program more frequently addressed activity, and the cost per patient was reduced by 37.1%. Patient satisfaction rates also improved .

DISCUSSION: A motivated team with representatives of the services involved was able to analyze and dramatically improve an important but complicated program.

Flintoft VF; Williams JI; Williams RC; Basinski AS; Blackstien-Hirsch P; Naylor CD
Institute for Clinical Evaluative Sciences, Toronto, Ont.
CMAJ (Canada) May 19 1998, 158 (10) p1289-96

BACKGROUND: Previous studies of hospital utilization have not taken into account the use of acute care beds for subacute care. The authors determined the proportion of patients who required acute, subacute and nonacute care on admission and during their hospital stay in general hospitals in Ontario. From this analysis, they identified areas where the efficiency of care delivery might be improved .

METHODS: Ninety-eight of 189 acute care hospitals in Ontario, at 105 sites, participated in a review that used explicit criteria for rating acuity developed by Inter-Qual Inc., Marlborough, Mass. The records of 13,242 patients who were discharged over a 9-month period in 1995 after hospital care for 1 of 8 high-volume, high-variability diagnoses or procedures were randomly selected for review. Patients were categorized on the basis of the level of care (acute, subacute or nonacute) they required on admission and during subsequent days of hospital care.

RESULTS: Of all admissions, 62.2% were acute, 19.7% subacute and 18.1% nonacute. The patients most likely to require acute care on admission were those with acute myocardial infarction (96.2% of 1826 patients) or cerebrovascular accident (84.0% of 1596 patients) and those admitted for elective surgery on the day of their procedure (73.4% of 3993 patients). However, 41.1% of patients awaiting hip or knee replacement were admitted the day before surgery so did not require acute care on admission. The proportion of patients who required acute care on admission and during the subsequent hospital stay declined with age; the proportion of patients needing nonacute care did not vary with age. After admission, acute care was needed on 27.5% of subsequent days, subacute care on 40.2% and nonacute care on 32.3%. The need for acute care on admission was a predictor of need for acute care during subsequent hospital stay among patients with medical conditions. The proportion of patients requiring subacute care during the subsequent hospital stay increased with age, decreased with the number of inpatient beds in each hospital and was highest among patients with congestive heart failure, chronic obstructive pulmonary disease and pneumonia.

INTERPRETATION: In 1995, inpatients requiring subacute care accounted for a substantial proportion of nonacute care days in Ontario's general hospitals. These findings suggest a need to evaluate the efficiencies that might be achieved by introducing a subacute category of care into the Canadian health care system. Generally, efforts are needed to reduce the proportion of admissions for nonacute care and of in-hospital days for other than acute care.

Hom D; Desautel MG; Lumerman JH; Feraren RE; Badlani GH
Department of Urology, Long Island Jewish Medical Center, New Hyde Park, New York 11040, USA.
Urology (United States) May 1998, 51 (5) p708-13

OBJECTIVES: To report preliminary results from a modified pubovaginal sling procedure using polypropylene mesh as the sling suspended by nonabsorbable sutures anchored to the pubic tubercle with Vesica bone anchors.

METHODS: Thirty-five women with type III stress urinary incontinence (SUI) (with or without associated urethral hypermobility) or type II SUI with additional risk factors such as obesity, chronic obstructive pulmonary disease, or failed prior incontinence-correcting procedures underwent this modified pubovaginal sling procedure. Postoperative voiding status was evaluated during office follow-up visits and telephone surveys.

RESULTS: With a mean follow-up of 8.4 months (range 2 to 18), 32 women (91.4%) were dry, 1 improved, and 2 remained incontinent. The pubovaginal sling procedure was the only operation performed in 46% of patients, with a mean operative time of 72 minutes, a mean estimated blood loss of 137 mL, and a mean hospital period of 2.3 days. Patients on whom concomitant gynecologic procedures were performed had a mean duration of surgery of 122 minutes, a mean estimated blood loss of 202 mL, and a mean hospitalization period of 2.9 days. Thirteen women had preoperative urgency that persisted in 31% of patients. De novo urgency developed in 3 patients. Seven women required prolonged suprapubic tube drainage but no patient remained in permanent retention. There has been no infection or erosion.

CONCLUSIONS: Our experience with this modified pubovaginal sling procedure using polypropylene mesh and Vesica bone anchors showed excellent results with greater technical ease, minimal morbidity, and decreased hospitalization period when compared to a traditional pubovaginal sling performed in our hands. Additional follow-up will be needed to assess long-term efficacy.

Kasper CL; Deem S
Respiratory Care Department, Harborview Medical Center, Seattle, Washington 98104-2499, USA.
ckasper@u.washington.edu
Anesthesiology (United States) Apr 1998, 88 (4) p898-902

BACKGROUND: The negative-pressure test using a self-inflating bulb (SIB) during emergency intubation was studied to determine its reliability and predictive value in this setting.

METHODS: The endotracheal tube (ETT) position was tested in 300 consecutive patients undergoing in-hospital emergency endotracheal intubation. Immediately after intubation and before ETT cuff inflation, the following protocol was strictly followed: (1) an SIB was compressed, connected to the ETT, and released. A 10-s period was allowed for the bulb to inflate. (2) The ETT cuff was inflated, and the ETT position was confirmed using colorimetric or infrared carbon dioxide detection, or both, combined with clinical evaluation.

RESULTS: There were 19 esophageal intubations (6% incidence). The SIB correctly identified all patients with esophageal intubation (sensitivity, 100%) and correctly identified all but three ETTs placed in the trachea (specificity, 99%). The three tracheally placed tubes that were misidentified by the bulb syringe occurred during one case each of chronic obstructive pulmonary disease, copious secretions, and obesity; of note were three tracheally placed tubes that were misidentified by the carbon dioxide analyzers during cardiopulmonary resuscitation.

CONCLUSIONS: The SIB proved to be a sensitive and specific test for esophageal intubation in the emergency setting when used according to the protocol described, and it is complementary to carbon dioxide detection. The predictive value of the bulb syringe appears to be improved when a prolonged period for reinflation is allowed. It holds particular promise because of its low cost and portability.

Ketelaars CA; Huyer Abu-Saad H; Halfens RJ; Schlosser MA; Mostert R; Wouters EF
Department of Nursing Science, University of Limburg, Maastricht, The Netherlands.
Heart Lung (United States) Mar-Apr 1998, 27 (2) p109-20

OBJECTIVE: To investigate the effects of specialized respiratory home nursing care after discharge from a pulmonary rehabilitation center.

DESIGN: Pretest-posttest control group design. Patients in the experimental group were visited by a nurse who specializes in respiratory care, whereas the control group received care from nurses who did not specialize in respiratory care.

SETTING: Data were collected on admission, at program discharge, and 4 months and 9 months after discharge from a pulmonary rehabilitation center.

PATIENTS: One hundred fifteen patients were included in the study and observed for 1 year.

OUTCOME MEASURES: Health-related quality of life (HRQL), coping strategies, compliance, hospitalization, and satisfaction with the care provided.

RESULTS: Complete data sets were obtained from 78 patients with severe airflow obstruction (FEV1 = 41%; predicted +/- SD = 15). Corrections were made for the selective nonresponse, but did not lead to adjustments in outcome scores. In both groups, HRQL scores improved between admission and discharge, but deteriorated 4 months and 9 months after discharge. The only statistically significant short-term effect was found on the "activities" component of HRQL in favor of the control group. No differences were found between groups regarding coping, compliance, and hospitalization. Patients in the experimental group, however, were more satisfied with the care provided by the specialized community nurses.

CONCLUSIONS: The treatment intervention of specialized respiratory home nursing might not have been specific or intensive enough to result in outcome benefits . Secondly, the initial benefits from baseline pulmonary rehabilitation alone may have led to positive outcomes in both patient groups.

Hyland ME; Singh SJ; Sodergren SC; Morgan MP
Department of Psychology, University of Plymouth, UK.
mhyland@plymouth.ac.uk
Qual Life Res (England) Apr 1998, 7 (3) p227-33

One hundred and thirty-eight chronic obstructive pulmonary disease (COPD) patients completed the Breathing Problems Questionnaire (BPQ) before and after a comprehensive programme of rehabilitation. Examination of the changes on individual items showed improvement on 22 items, of which four items were significant at p < 0.05 and deterioration on nine items, of which two were significant at p < 0.01. All deteriorating items were consistent with lifestyle adaptations encouraged as part of the rehabilitation programme. We examined the psychometric properties of a reduced ten item version of the BPQ limited to the items most sensitive to change. We recommend the purpose-specific, disease-specific COPD scale for measuring change in pulmonary rehabilitation assessment in contrast to the longer 33 item questionnaire, which, however, may be more useful for cross-sectional assessment.

Chertow GM; Levy EM; Hammermeister KE; Grover F; Daley J
Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.
Am J Med (United States) Apr 1998, 104 (4) p343-8

PURPOSE: To determine whether there is an independent association of acute renal failure requiring dialysis with operative mortality after cardiac surgery.

PATIENTS AND METHODS: The 42,773 patients who underwent coronary artery bypass or valvular heart surgery at 43 Department of Veterans Affairs Medical Centers between 1987 and 1994 were evaluated to determine the association between acute renal failure sufficient to require dialysis and operative mortality, with and without adjustment for comorbidity and postoperative complications. Crude and adjusted odds ratios (OR) and 95% confidence intervals (95% CI) were derived from logistic regression analysis.

RESULTS: Acute renal failure occurred in 460 (1.1%) patients. Overall operative mortality was 63.7% in these patients, compared with 4.3% in patients without this complication. The unadjusted OR for death was 39 (95% CI 32 to 48). After adjustment for comorbid factors related to the development of acute renal failure (surgery type, baseline renal function, preoperative intraaortic balloon pump, prior heart surgery, NYHA class IV status, peripheral vascular disease, pulmonary rales, left ventricular ejection fraction below 35%, chronic obstructive pulmonary disease, systolic blood pressure, and the cross-product of systolic blood pressure and surgery type), the OR was 27 (95% CI 22 to 34). Further adjustment was made for seven postoperative complications (low cardiac output, cardiac arrest, perioperative myocardial infarction, prolonged mechanical ventilation, reoperation for bleeding or repeat cardiopulmonary bypass, stroke or coma, and mediastinitis), that were independently associated with operative mortality. The OR adjusted for comorbidity and postoperative complications associated with acute renal failure was 7.9 (95% CI 6 to 10).

CONCLUSIONS: Acute renal failure was independently associated with early mortality following cardiac surgery, even after adjustment for comorbidity and postoperative complications. Interventions to prevent or improve treatment of this condition are urgently needed.

Goldstein LB; Samsa GP; Matchar DB; Oddone EZ
Center for Clinical Health Policy Research, Division of Neurology, Duke University, Department of Veterans Affairs Medical Center, Durham, NC, USA.
golds004@mc.duke.edu
Stroke (United States) Apr 1998, 29 (4) p750-3

BACKGROUND AND PURPOSE: The benefit of carotid endarterectomy is highly dependent on surgical risk. However, little data are available concerning factors affecting the risk of endarterectomy performed for asymptomatic carotid artery stenosis outside the setting of a randomized controlled trial. The purpose of this study was to analyze the impact of potential preoperative risk factors on the frequency of postoperative complications in patients undergoing the operation for asymptomatic disease in academic medical centers.

METHODS: Data regarding postoperative complications were systematically abstracted from the medical records of a random sample of patients who underwent carotid endarterectomy at 12 academic medical centers.

RESULTS: Of 1160 procedures reviewed, 463 (40%) were performed for asymptomatic disease. Postoperative stroke or death occurred in 13 (2.8%), and myocardial infarction occurred in 8 (1.7%). The rate of postoperative stroke or death was lower in asymptomatic patients than in those with a history of cerebrovascular symptoms in a different vascular distribution, but the difference was not significant (1.8% versus 4.2%; P=.21). There were no significant differences in these rates based on race, a history of angina, recent myocardial infarction, chronic obstructive pulmonary disease, hypertension, the degree of stenosis of the contralateral or ipsilateral carotid artery, or the presence of angiographically recognized ulceration, intraluminal thrombus, or siphon stenosis in the ipsilateral vessel (chi(2); P>.05). Postoperative stroke or death was more frequent in women (5.3% versus 1.6% in men; P=.02), in those aged 75 years or older (7.8% versus 1.8% in those younger than 75 years; P=.01), and in those with a history of congestive heart failure (8.6% versus 2.3% in those without a history of congestive heart failure; P=.03). The risk of stroke or death was higher in the 16 patients who had carotid endarterectomy performed in combination with coronary artery bypass surgery than in those who had only endarterectomy (18.7% versus 2.1%; P<.001).

CONCLUSIONS: The overall risk of postoperative stroke or death was nearly twice that reported by Asymptomatic Carotid Atherosclerosis Study (ACAS) investigators in the setting of a clinical trial but was within acceptable guidelines. Women were at higher postoperative risk than men, which supported ACAS findings. Additional high-risk groups were those aged 75 years or older, those with a history of congestive heart failure, and those undergoing prophylactic endarterectomy for asymptomatic stenosis in combination with coronary surgery. Knowledge of these rates may help to better assess an individual's postoperative risk and therefore the anticipated benefit of surgery.

Nava S; Ambrosino N; Clini E; Prato M; Orlando G; Vitacca M; Brigada P; Fracchia C; Rubini F
Centro Medico di Riabilitazione di Montescano, Italy.
Ann Intern Med (United States) May 1 1998, 128 (9) p721-8

BACKGROUND: In patients with acute exacerbations of chronic obstructive pulmonary disease, mechanical ventilation is often needed. The rate of weaning failure is high in these patients, and prolonged mechanical ventilation increases intubation-associated complications.

OBJECTIVE: To determine whether noninvasive ventilation improves the outcome of weaning from invasive mechanical ventilation.

DESIGN: Multicenter, randomized trial.

SETTING: Three respiratory intensive care units. PATIENTS: Intubated patients with chronic obstructive pulmonary disease and acute hypercapnic respiratory failure.

INTERVENTION: A T-piece weaning trial was attempted 48 hours after intubation. If this failed, two methods of weaning were compared: 1) extubation and application of noninvasive pressure support ventilation by face mask and 2) invasive pressure support ventilation by an endotracheal tube.

MEASUREMENTS: Arterial blood gases, duration of mechanical ventilation, time in the intensive care unit, occurrence of nosocomial pneumonia, and survival at 60 days.

RESULTS: At admission, all patients had severe hypercapnic respiratory failure (mean pH, 7.18+/-0.06; mean PaCO2, 94.2+/-24.2 mm Hg), sensory impairment, and similar clinical characteristics. At 60 days, 22 of 25 patients (88%) who were ventilated noninvasively were successfully weaned compared with 17 of 25 patients (68%) who were ventilated invasively. The mean duration of mechanical ventilation was 16.6+/-11.8 days for the invasive ventilation group and 10.2+/-6.8 days for the noninvasive ventilation group (P = 0.021). Among patients who received noninvasive ventilation, the probability of survival and weaning during ventilation was higher (P = 0.002) and time in the intensive care unit was shorter (15.1+/-5.4 days compared with 24.0+/-13.7 days for patients who received invasive ventilation; P = 0.005). Survival rates at 60 days differed (92% for patients who received noninvasive ventilation and 72% for patients who received invasive ventilation; P = 0.009). None of the patients weaned noninvasively developed nosocomial pneumonia, whereas 7 patients weaned invasively did.

CONCLUSIONS: Noninvasive pressure support ventilation during weaning reduces weaning time, shortens the time in the intensive care unit, decreases the incidence of nosocomial pneumonia, and improves 60-day survival rates.

Sulmasy DP; Terry PB; Weisman CS; Miller DJ; Stallings RY; Vettese MA; Haller KB
Georgetown University Medical Center, Washington, DC 20007, USA.
sulmasyd@gunet.georgetown.edu
Ann Intern Med (United States) Apr 15 1998, 128 (8) p621-9

BACKGROUND: Patients' loved ones often make end-of-life treatment decisions, but the accuracy of their substituted judgments and the factors associated with accuracy are poorly understood.

OBJECTIVE: To assess the accuracy of judgments made by surrogate decision makers; ascertain the beliefs, practices, and clinical and sociodemographic factors associated with accuracy of surrogates' decisions; assess the preferences of patients for life-sustaining treatments; and compare differences in accuracy across diagnoses.

DESIGN: Cross-sectional paired interviews.

SETTING: Outpatient practices of three university hospitals.

PATIENTS: 250 patients with terminal diagnoses of congestive heart failure, AIDS, amyotrophic lateral sclerosis, lung cancer, and chronic obstructive pulmonary disease (50 patient-surrogate pairs in each group) and 50 general medical patients and their surrogates.

MEASUREMENTS: The accuracy of surrogate predictions was measured by using scales based on 10 potential treatments in each of three hypothetical clinical scenarios.

RESULTS: Preferences varied according to mode of treatment and scenario. On average, surrogates made correct predictions in 66% of instances. Accuracy was better for the permanent coma scenario than for the scenarios of severe dementia or coma with a small chance of recovery (P < 0.001). In a binary logit model, the accuracy of substituted judgments was positively associated with the patient having spoken with the surrogate about end-of-life issues (odds ratio [OR], 1.9 [95% CI, 1.6 to 2.3]), the patient having private insurance (OR, 1.4 [CI, 1.1 to 1.7]), the surrogate's level of education (OR, 1.5 [CI, 1.2 to 1.9]), and the patient's level of education (OR, 1.7 [CI, 1.4 to 2.2]). Accuracy was negatively associated with the patient's belief that he or she would live longer than 10 years (OR, 0.6 [CI, 0.5 to 0.7]), surrogate experience with life-sustaining treatment (OR, 0.4 [CI, 0.3 to 0.5]), surrogate participation in religious services (OR, 0.67 [CI, 0.50 to 0.91]), and a diagnosis of heart failure (OR, 0.6 [CI, 0.5 to 0.8]). Age, ethnicity, marital status, religion, and advance directives were not associated with accuracy.

CONCLUSIONS: The accuracy of substituted judgments is associated with multiple clinically apparent patient and surrogate factors. This information can help clinicians identify conditions under which substituted judgments are likely to be accurate or inaccurate and can help target populations for education designed to improve the accuracy of surrogate decision making.

Schellenberg D; Pare PD; Weir TD; Spinelli JJ; Walker BA; Sandford AJ
Respiratory Health Network of Centres of Excellence, University of British Columbia Pulmonary Research Laboratory, St. Paul's Hospital, Vancouver, Canada.
Am J Respir Crit Care Med (United States) Mar 1998, 157 (3 Pt 1) p957-61

Although the development of chronic obstructive pulmonary disease (COPD) in smokers shows genetic susceptibility, only alpha1-antitrypsin deficiency has been identified as a definite genetic risk factor. There have been three previous studies in which associations between Gc-globulin phenotypes and COPD have been investigated. Although some data suggest an association, the were inconclusive. Because smoking is the major risk factor for COPD, it may have been a confounding factor in previous studies. We have investigated Gc-globulin genotypic frequencies among 75 COPD patients and 64 nonobstructed controls. Both groups had significant smoking histories: pack-years (mean +/- SD) of 52 +/- 30 and 48 +/- 27, respectively. The results show that homozygosity for the Gc2 allele is protective against COPD (OR = 0.17, 95% CI = 0.03 to 0.83). There were no differences between genotypes for lung elastic recoil values or for the level of upstream airway resistance. Gc-globulin can enhance complement (C5a)-mediated neutrophil chemotaxis. Because neutrophils play a role in parenchymal destruction and airway inflammation, we examined whether Gc-globulin's ability to enhance neutrophil chemotaxis varied with genotype. We found no difference among genotypes with respect to neutrophil chemotaxis suggesting that the protective effect of the Gc2 allele is mediated through a different mechanism.

Leuppi JD; Zenhausern R; Schwarz F; Frey WO; Villiger B
Thurgauer Schaffhauser Hohenklinik, Davos-Platz.
jorgl@med.usyd.edu.au
Dtsch Med Wochenschr (Germany) Feb 13 1998, 123 (7) p174-8

BACKGROUND AND OBJECTIVE: Patients with COPD often have exertional dyspnoea. They are incapacitated less by impairment of pulmonary function than by deconditioning of the cardiovascular and muscular systems. Pulmonary rehabilitation through the currently customary "low intensity" training programme can at best achieve limited improvement of aerobic capacity. The aim of this study was to clarify whether in the course of in-patient rehabilitation with a medical "high intensity" training regimen patients with COPD can better their endurance capacity (e.c.).

PATIENTS AND METHODS: Eleven patients with mild to moderate COPD (ten men, one woman; average age 59 [54-76] years) participated. In addition to optimal drug treatment they undertook "high intensity" training (to 85-95% of maximally achievable heart rate).

RESULTS: The patients achieved significant (P < 0.05) improvement in maximal oxygen uptake, maximal performance and walking distance in the 6-minute walking test.

CONCLUSION: Medically supervised "high intensity" training can produce a significant rise in endurance capacity even in patients with COPD.

Boulet L.-P.; Turcotte H.; Hudon C.; Carrier G.; Maltais F.
Dr. L.-P. Boulet, Hopital Laval, 2725 Chemin Sainte-Foy, Sainte-Foy, Que. G1V 4G5 Canada
Canadian Respiratory Journal (Canada), 1998, 5/4 (270-277)

OBJECTIVES: To compare clinical features, pulmonary function and high-resolution computed chest tomography (HRCT) findings of asthmatic patients with a component of incomplete reversibility of airflow obstruction (AIRAO) with those of patients with smoking-induced chronic obstructive pulmonary disease (COPD).

METHODS: Thirteen patients with COPD (six males and seven females, mean age 59 years, mean smoking 50.5 pack-years) and 14 patients with AIRAO (six males and eight females, mean age 52 years) despite optimal treatment, with no significant smoking history (mean 1.5 pack-years) and no significant environmental exposure or any other respiratory disease, were studied. Patients had respiratory questionnaires, pulmonary function tests, allergy skin-prick tests and an HRCT to evaluate possible parenchymal or bronchial abnormalities. Eight patients in each group also had exercise tests. All patients were stable at the time of the study.

RESULTS: As expected, atopy was more prevalent in AIRAO (n = 13) than in COPD (n = 1) patients. Mean forced expiratory volume in 1 s (FEV1) and forced vital capacity (percentage of predicted value) were 39% and 61%, respectively, in COPD patients and 49% and 71%, respectively, in AIRAO patients; FEV1 improved by 18% in COPD patients and and by 22% in AIRAO patients after use of inhaled salbutamol. Mean functional residual capacity was greater in COPD patients than in AIRAO patients (178% versus 144% of the predicted value), while the mean carbon monoxide diffusing capacity of the lungs (DLCO) was lower in COPD patients than in AIRAO patients (62% versus 89% of the predicted value). Exercise tolerance was similar in both groups, as were postexercise changes in arterial oxygen pressure (PaO2). Emphysematous changes were observed in COPD patients and AIRAO patients who had evaluable HRCTs (10 versus two patients, although very mild in asthma), bronchial dilations (zero versus six patients), bronchial wall thickening (two versus eight patients) and an acinar pattern (one versus five patients). Mean thickness of the large airway wall to outer diameter (intermediary bronchus) ratio was 0.176 in COPD and 0.183 in AIRAO (P > 0.05).

CONCLUSIONS: Asthma may lead to physiological features similar to COPD but may be distinguished by demonstrating a preserved DLCO and a higher ratio of airway to parenchymal abnormalities on HRCT scan.

Dureuil B.; Matuszczak Y.
B. Dureuil, Departement d'anesthesie-reanimation, Hopital Charles Nicolle, 1 rue de Germont, 76031 Rouen cedex France
Reproduction Nutrition Development (France), 1998, 38/2 (175-180)

Diet-induced undernutrition causes deleterious changes in the structure and function of the diaphragm muscle. Diseases associated with somatic washing cause atrophy of the respiratory muscles. In cachectic subjects, the diaphragm muscle mass and thickness are reduced in proportion to the reduction in body weight. In addition, respiratory muscle strength and endurance are reduced more dramatically than the weight loss. This finding suggests that malnutrition induces a reduction in muscular mass which is associated with a decrease in contractility. Diaphragmatic weakness may increase the risk of respiratory failure in patients with chronic obstructive pulmonary disease (COPD). The primary goal of a successful nutritional programme is to improve the diaphragm strength by correcting the mineral, electrolyte and energetic disturbances at the muscular level, the latter being responsible for the decreased contractability associated with malnutrition.

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