Whole-lung lavage: a successful treatment for restoring acinar ventilation distribution in primary acquired pulmonary alveolar proteinosis.

A 51-year-old active smoker with primary acquired pulmonary alveolar proteinosis (PAP) diagnosed by biopsy and anti-GM-CSF antibodies was treated safely with whole-lung lavage (WLL). This resulted in a rapid improvement of symptoms and arterial blood oxygenation, but not of standard lung function parameters. However, we also performed the multiple-breath nitrogen washout (MBW) test to determine the lung clearance index (LCI) as well as indices of acinar ventilation heterogeneity (S(acin)) and conductive ventilation heterogeneity (S(cond)). At baseline, a distinct abnormality was seen for S(acin) and LCI, while S(cond) was at the upper limit of normal for this subject. S(acin), in particular, was in excess of the S(acin) abnormality corresponding to a 20-pack-year smoking history. Immediately after WLL, S(acin) and S(cond) both fell to within a normal range while LCI also decreased but remained abnormal. The S(acin) decrease was much greater than the S(cond) decrease, which was to be expected after 1 week of smoking cessation at the hospital (smoking was resumed after release from hospital). A follow-up visit 7 weeks after WLL revealed a spectacular improvement on CT scan and improvements in standard lung function. Another follow-up visit 14 weeks after WLL showed further improvements in standard lung function, and both S(acin) and S(cond) remained well within the normal range, and LCI was above the upper limit of normal. We conclude that in this patient, removal of excess surfactant by WLL resulted in a restored ventilation distribution in most of the distal air spaces.

Forced vital capacity and forced expiratory volume in six seconds as predictors of reduced total lung capacity.

The present study aims to derive guidelines that identify patients for whom spirometry can reliably predict a reduced total lung capacity (TLC). A total of 12,693 lung function tests were analysed on Caucasian subjects, aged 18-70 yrs. Restriction was defined as a reduced TLC. Lower limits of normal (LLN) for TLC were obtained from the European Respiratory Society recommended reference equations. Reference equations from the National Health and Nutrition Examination Survey III were used for forced vital capacity (FVC) and forced expiratory volume in six seconds (FEV(6)). The performance of FVC and FEV(6) to predict the presence of restriction was studied as follows: 1) using two-by-two (2x2) tables; and 2) by logistic regression analysis. Both analyses were performed in obstructive (defined as forced expiratory volume in one second (FEV(1))/FVC or FEV(1)/FEV(6) 100% pred (males) or >85% pred (females). In obstructive patients, spirometry cannot reliably diagnose a concomitant restrictive defect, but it can rule out restriction for patients with forced vital capacity or forced expiratory volume in six seconds >85% pred (males) or >70% pred (females).

Chest physiotherapy in cystic fibrosis: short-term effects of autogenic drainage preceded by wet inhalation of saline versus autogenic drainage preceded by intrapulmonary percussive ventilation with saline.

BACKGROUND: Chest physiotherapy has been used for many years to assist in the removal of abnormal viscid bronchial secretions in cystic fibrosis (CF) patients. OBJECTIVES: This study compared the short-term effects of two physiotherapy regimens in patients with CF: autogenic drainage (AD) preceded by either saline inhalation ('saline(NEB) + AD') or by intrapulmonary percussive ventilation (IPV) with saline ('saline(IPV) + AD'). METHODS: In a randomized crossover design, 20 clinically stable CF patients with similar pulmonary function at baseline received either 'saline(NEB) + AD' or 'saline(IPV) + AD' on 2 consecutive days. Transcutaneous oxygen saturation, heart rate, Borg dyspnea score and mucus wet weight were evaluated after 15 min of either saline(NEB) or saline(IPV), and after a subsequent 30 min of AD. RESULTS: There were no significant changes in oxygen saturation, heart rate or Borg score at any point of either physiotherapy intervention. There was no significant difference in sputum wet weight recovered with either saline(NEB) (2.2 +/- 1.8 g, mean +/- SD) or saline(IPV) (1.7 +/- 1.9 g) alone. Subsequent AD did produce significantly greater amounts of sputum wet weight (p < 0.0001 for both) than in the initial saline delivery period, yet the amount of wet weight was similar irrespective of whether AD was preceded by saline(NEB) (9.7 +/- 6.5 g) or saline(IPV) (11.6 +/- 7.3 g). CONCLUSIONS: Recovered sputum weight is similar whether AD is preceded by saline(NEB) or saline(IPV). The much greater amount of mucus obtained during the AD period than during the saline delivery period warrants further investigation.

Impact of a single 10 min education session on asthma control as measured by ACT.

BACKGROUND: Aim: Despite the availability of effective treatments for asthma, many patients still suffer from uncontrolled asthma. This study evaluates whether a single educational session could improve asthma control assessed by Asthma Control Test (ACT) score as well as knowledge of the inhaler device, knowledge of medication and inhalation technique. METHODS: This prospective single blinded randomized controlled trial of 160 adults with asthma, examined the effectiveness of a single standardized, educational intervention, performed by a respiratory nurse specialist. The education provided to the intervention group consisted of basic information about asthma treatment and instructions on inhalation technique for about 10min. This additional education was not offered to the control group. In both groups ACT scores, knowledge of medication, knowledge of inhaler device and inhalation technique were assessed at baseline and after three months. Asthma was considered well-controlled when the ACT score exceeded 19. RESULTS: At baseline there were no significant differences in patient demographics, degree of asthma control, knowledge of medication or device and inhalation technique between the intervention group and the control group. In the intervention group the educational session resulted in a significantly higher proportion of well-controlled asthma patients with an ACT>19 (43% versus 77%) (p < 0.001) after three months. In the control group this proportion remained similar (57% versus 67%) (p > 0.1). We also observed improvements in knowledge of medication (p < 0.001), knowledge of device (p < 0.001) and inhalation technique (p = 0.004) in the intervention group and not in the control group. CONCLUSION: A single 10 min, educational session provided by a respiratory nurse specialist can substantially improve asthma control determined by the ACT score after three months.

Increase in ventilated air spaces after eradication of chronic methicillin-resistant Staphylococcus aureus infection in cystic fibrosis patients.

Effective microbiogical eradication of methicillin-resistant Staphylococcus aureus (MRSA) in patients with cystic fibrosis (CF) can be obtained, but its effect is not always clear-cut in terms of spirometric indices. The aim of this observational prospective cohort study was to study the potential effect of eradication of chronic MRSA infection on lung function including ventilation distribution. Six CF patients, chronically colonized with MRSA (median age: 21 years (range 14-46); median FEV1: 76 (95%CI 58-98)%pred) were successfully eradicated using oral rifampicin and fusidic acid in combination with topical decolonization measures. Lung function and multiple breath washout test were performed at the start and at the end of the eradication protocol and after an average follow-up period of 7·5±1·5(SD) months. One patient cultured MRSA again 4 months after successful eradication. All patients reported reduced sputum production and viscosity. By the end of the follow-up period, there was an increase in ventilated FRCMBW and no change in plethysmographic FRCPL. This resulted in a significant decrease of trapped air by half a litre (from 579 to 40 ml; P = 0·013). Lung clearance index (LCI) also showed a small but significant decrease (from 7·2 to 6·7; P = 0·014) after eradication of MRSA. We conclude that MRSA eradication can be successful, also in terms of recruitment of previously unventilated air spaces, potentially due to reduced sputum production and/or viscosity.

Saline aerosol bolus dispersion. I. The effect of acinar airway alteration.

We explored the possibility of using a saline aerosol for bolus dispersion measurements to detect peripheral airway alterations in smokers. Indexes of ventilation inhomogeneity in conductive (S(cond)) and acinar (S(acin)) lung zones, as derived from the multiple-breath N(2) washout (Verbanck S, Schuermans D, Van Muylem A, Noppen M, Paiva M, and Vincken W, J Appl Physiol 83: 1807-1816, 1997), were also measured. The saline bolus test consisted of inhaling 60-ml saline aerosol boluses to different volumetric lung depths (VLD) in the 1.1 liter volume above functional residual capacity. In the never-smoker group (n = 12), saline boluses showed bolus dispersion values consistent with normal values reported in the literature for 0.5- to 1-microm aerosols. In the smoker group (n = 12; 28 +/- 9 pack years, mean +/- SD), significant increases were seen on dispersion and skew of the most peripherally inhaled saline boluses (VLD = 800 ml; P < 0.05) as well as on S(acin) (P = 0.007) with respect to never-smokers. Shallow inhaled boluses (VLD = 200 ml) and S(cond) did not reveal any significant differences between smokers and never-smokers. This study shows the consistent response of two conceptually independent tests, in which both saline aerosol and gas-derived indexes point to a heterogeneous distribution of smoking-induced structural alterations in the lung periphery.

Saline aerosol bolus dispersion. II. The effect of conductive airway alteration.

In a companion study (Verbanck S, Schuermans D, Vincken W, and Paiva M, J Appl Physiol 90: 1754-1762, 2001), we investigated whether saline aerosol bolus tests could also be used to detect proximal, as opposed to peripheral, airway alterations. We studied 10 never-smokers before and after histamine challenge, obtaining, for various volumetric lung depths (VLD), saline bolus-derived indexes computed by discarding aerosol concentrations below either 50% of the exhaled bolus maximum (half-width, H) or below cutoffs ranging from 5 to 25% (standard deviation, sigma(5%)-sigma(25%)) and skew (sk(5)-sk(25%)). Multiple-breath N(2) washout-derived indexes of conductive (S(cond)) and acinar (S(acin)) ventilation inhomogeneity were also determined. After histamine, S(cond) significantly increased (P = 0.008) whereas S(acin) remained unaffected, indicating purely conductive airway alteration. Consistent with this observation, sk(5%) (or sk(25%)) was increased to the same extent at all VLD, and sigma(5%) was increased preferentially at low VLD. By contrast, H and sigma(25%) displayed preferential increases at high VLD, a pattern similar to that induced by peripheral alterations. The present work shows that proximal airway alteration can be reliably identified by saline bolus tests only if these include measurements at low and high VLD and if bolus dispersion is quantified as a standard deviation with a low cutoff.

Methacholine versus histamine: paradoxical response of spirometry and ventilation distribution.

We investigated the differential effect of histamine and methacholine on spirometry and ventilation distribution (where indexes S(cond) and S(acin) represent conductive and acinar ventilation heterogeneity; Verbanck S, Schuermans D, Van Muylem A, Noppen M, Paiva M, and Vincken W. J Appl Physiol 83: 1807-1816, 1997). Thirty normal subjects were challenged with cumulative doses of 6.52 micromol histamine and, on a separate day, with either 6.67 micromol methacholine (equal-dose group; n = 15) or 13.3 micromol methacholine (double-dose group; n = 15). Largest average forced expiratory volume in 1 s (FEV(1)) decreases or S(cond) increases obtained in either group were -9% and +286%, respectively; S(acin) remained unaffected at all times. In the equal-dose group, a smaller FEV(1) decline (P = 0.002) after methacholine was paralleled by a smaller S(cond) increase (P = 0.041) than with histamine. However, in the double-dose group, methacholine maintained a smaller FEV(1) decline (P = 0.009) while inducing a larger S(cond) increase (P = 0.006) than did histamine. The differential action of histamine and methacholine is confined to the conductive airways, where histamine likely causes the greatest overall airway narrowing and methacholine induces the largest parallel heterogeneity in airway narrowing, probably at the level of the large and small conductive airways, respectively. The observed ventilation heterogeneities predict a risk for dissociation between ventilation-perfusion mismatch and spirometry, particularly after methacholine challenge.

Ventilation distribution during histamine provocation.

We investigated ventilation inhomogeneity during provocation with inhaled histamine in 20 asymptomatic nonsmoking subjects. We used N2 multiple-breath washout (MBW) to derive parameters Scond and Sacin as a measurement of ventilation inhomogeneity in conductive and acinar zones of the lungs, respectively. A 20% decrease of forced expiratory volume in 1 s (FEV1) was used to distinguish responders from nonresponders. In the responder group, average FEV1 decreased by 26%, whereas Scond increased by 390% with no significant change in Sacin. In the nonresponder group, FEV1 decreased by 11%, whereas Scond increased by 198% with no significant Sacin change. Despite the absence of change in Sacin during provocation, baseline Sacin was significantly larger in the responder vs. the nonresponder group. The main findings of our study are that during provocation large ventilation inhomogeneities occur, that the small airways affected by the provocation process are situated proximal to the acinar zone where the diffusion front stands, and that, in addition to overall decrease in airway caliber, there is inhomogeneous narrowing of parallel airways.

Obstructive and restrictive spirometric patterns: fixed cut-offs for FEV1/FEV6 and FEV6.

The purpose of this study was to determine fixed cut-off points for forced expiratory volume in one second (FEV(1))/FEV(6) and FEV(6) as an alternative for FEV(1)/forced vital capacity (FVC) and FVC in the detection of obstructive and restrictive spirometric patterns, respectively. For the study, a total of 11,676 spirometric examinations, which took place on Caucasian subjects aged between 20-80 yrs, were analysed. Receiver-operator characteristic curves were used to determine the FEV(1)/FEV(6) ratio and FEV(6) value that corresponded to the optimal combination of sensitivity and specificity, compared with the commonly used fixed cut-off term for FEV(1)/FVC and FVC. The data from the current study indicate that FEV(1)/ FEV(6) <73% and FEV(6) <82% predicted can be used as a valid alternative for the FEV(1)/FVC <70% and FVC <80% pred cut-off points for the detection of obstruction and restriction, respectively. The statistical analysis demonstrated very good, overall, agreement between the two categorisation schemes. For the spirometric diagnosis of airway obstruction (prevalence of 45.9%), FEV(1)/FEV(6) sensitivity and specificity were 94.4 and 93.3%, respectively; the positive and negative predictive values were 92.2 and 95.2%, respectively. For the spirometric detection of a restrictive pattern (prevalence of 14.9%), FEV(6) sensitivity and specificity were 95.9 and 98.6%, respectively; the positive and negative predictive values were 92.2 and 99.3%, respectively. This study demonstrates that forced expiratory volume in one second/forced expiratory volume in six seconds <73% and forced expiratory volume in six seconds <82% predicted, can be used as valid alternatives to forced expiratory volume in one second/forced vital capacity <70% and forced vital capacity <80% predicted, as fixed cut-off terms for the detection of an obstructive or restrictive spirometric pattern in adults.

Evidence of acinar airway involvement in asthma.

We investigated acinar airway involvement in 20 patients with stable asthma, using the phase III slope analysis of the multiple breath N2 washout previously applied in a group of patients with COPD (Am. J. Respir. Crit. Care Med. 1998;157:1573-1577). This technique quantifies severity of conductive and acinar components of ventilation maldistribution separately, through indices S(cond) and S(acin), which increase when respective ventilation inhomogeneities increase. We also investigated the effect of salbutamol inhalation on S(cond) and S(acin) in patients with asthma and compared it with that obtained in patients with COPD. Baseline measurements in the patients with asthma show that (1) acinar ventilation inhomogeneity was indeed abnormal in patients with asthma (S(acin) = 0.195 +/- 0.026 L-1) despite the normal diffusing capacity in this group; S(acin) values were intermediate between those obtained in unaffected individuals and patients with COPD, and that (2) conductive ventilation inhomogeneity was abnormal in the patients with asthma (S(cond) = 0.076 +/- 0.006 L-1) but similar to that obtained in the patients with COPD. Measurements after salbutamol inhalations showed significant changes in S(cond) and S(acin) only in the patients with asthma (p < 0.001). This study primarily demonstrated significant, but partially reversible, acinar airway impairment in patients with asthma, as compared with the more severe baseline acinar airway impairment in patients with COPD, which was not reversible after salbutamol inhalation.

Conductive and acinar lung-zone contributions to ventilation inhomogeneity in COPD.

We investigated ventilation inhomogeneity in patients with chronic obstructive pulmonary disease (COPD) through use of the multiple breath N2 washout test (MBW). From an alveolar slope analysis throughout the MBW, we derived two indices, S(cond) and S(acin), as a measure of ventilation inhomogeneity in conductive and acinar zones of the lungs, respectively (J. Appl. Physiol. 1997;83:1807-1816). We evaluated the relationship of S(cond) and S(acin) to standard lung-function indices by means of a principal-components factor analysis, which linked correlated indices to independent factors accounting for 81% of the total variance within the COPD group. S(acin) was linked to the so-called acinar lung-zone factor, which also comprises diffusion capacity measurements. S(cond) was linked to the so-called conductive lung-zone factor, which also comprises specific airway conductance (S(Gaw)) and forced expiratory flows. FEV1 divided by FVC (FEV1/FVC) was the only variable linked to both the conductive and the acinar lung-zone factors. The fact that S(cond) and S(acin) were linked to independent factors provides statistical confirmation of the hypothesis that S(cond) and S(acin) reflect independent lung alterations, whereas FEV1/FVC behavior indicates a combined conductive and acinar contribution to airways obstruction.