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Respirology (2014) 19 (Suppl. 2), 2–6

doi: 10.1111/resp.12260

AO 002

ANZSRS ORAL PRESENTATIONS AO 001

SAMPLING METHOD AND ANALYSER SELECTION ARE IMPORTANT DETERMINANTS IN ACCURACY OF POINT-OF-CARE TESTING FOR BLOOD GAS MEASUREMENT HARNETT L1, JOHNSTON S2, THORNTON A3 Royal Adelaide Hospital, 2Royal Adelaide Hospital, 3Royal Adelaide Hospital

1

Introduction: Capillary sampling as a surrogate for arterial puncture and the I-STAT analyser (Abbott Laboratories, Princeton, USA) are used for point-ofcare testing despite conflicting validation studies. Aim: To determine if capillary blood and I-STAT produce comparable results to conventional arterial blood gas sampling and analysis (ABL725, Radiometer, Copenhagen, Denmark). Method: • Experiment 1: Brachial arterial samples from 40 patients were analysed with ABL725 (Syringe), then promptly injected into a capillary tube (CapTube) and analysed on the ABL725. • Experiment 2: Brachial arterial and capillary ear lobe samples (CapEar) were taken from a further 40 patients and analysed on the ABL725. • Experiment 3: As cartridge temperature is known to affect I-STAT results, brachial arterial samples from 25 patients were analysed on the ABL725, then immediately, in random order, through two I-STAT cartridges left out of refrigeration for 20 (I-STAT20) and 30 minutes (I-STAT30) and then re-analysed on the ABL725. Data were analysed using ANOVA and paired t-tests with significance set at p < 0.05. Results: • Experiment 1 and 2: All capillary values were statistically different from syringe and arterial, but only PaO2 (Experiment 1 and 2) and Hb (Experiment 2 only) were clinically different. • Experiment 3: All ABL725 measurements were statistically different to I-STAT but PaO2 was clinically different. The difference was smaller if cartridges were removed from refrigeration for 30 rather than 20 minutes.

Parameter

SyringeCapTube

ArterialCapEar

ABL725-ISTAT 30

I-STAT20-ISTAT 30

pH −0.0027 ± 0.0034* −0.015 ± 0.016* −0.0063 ± 0.007§ −0.0012 ± 0.0051 PaCO2 (mmHg) −0.59 ± 0.79* 0.81 ± 2.4§ −0.65 ± 0.70* −0.068 ± 0.52 PaO2 (mmHg) 4.34 ± 0.92* 11.0 ± 7.5* 2.73 ± 1.3* −3.28 ± 2.3* Hb (g/L) −2.1 ± 1.4* −6.9 ± 4.6* 1.28 ± 5.1 −0.08 ± 2.5 § § SaO2 (%) −0.37 ± 0.43 0.83 ± 2.1 1.9 ± 1.5* −0.2 ± 0.58 p < 0.05 *p < 0.0001

§

Conclusion: Compounding errors in capillary blood gas sampling and analysis do not make it a viable alternative for measuring PaO2 or Hb. Limitations of I-STAT including cartridge temperature must be understood before use in point-of-care testing. Key words: capillary blood, arterial blood, I-STAT. Nomination for Young Investigator Award Grant Support: I-STAT cartridges donated by Abbott Laboratories.

© 2014 The Authors Respirology © 2014 Asian Pacific Society of Respirology

UTILITY OF IMPULSE OSCILLOMETRY IN DETECTING UPPER AIRWAY DYSFUNCTION DURING HYPERTONIC SALINE CHALLENGE LEWIS A1, PRETTO J1,2, GIBSON P1,2 Department of Respiratory & Sleep Medicine, John Hunter Hospital, Newcastle, NSW, 2School of Medicine & Public Health, University of Newcastle, Newcastle, NSW

1

Aim: Upper airway dysfunction (UAD) is an important clinical entity thought to result from hyper-responsiveness of the extra-thoracic airway and can be detected using hypertonic saline challenge (HSC).1 It is characterised by the development of increased upper airway resistance. The aim of this study was to investigate whether impulse oscillometry (IOS) can be used during HSC to identify UAD, and what IOS variables might provide best diagnostic utility. Methods: Patients attending the Pulmonary Function Laboratory for clinically requested HSC were invited to participate. IOS (Jaeger Masterscreen) during tidal breathing was performed at baseline and following each dose of hypertonic saline delivered in accordance with usual bronchial hyper-reactivity assessment. Flow-volume loops were performed after each IOS measurement. Patients were classified as having bronchial hyper-reactivity (BHR) if PD15 < 19 ml, as having UAD if mid inspiratory flow fell ≥20%1, or as normal otherwise. Results: 105 patients (68% female) participated and the median (IQR) %changes in tidal-breathing IOS data from baseline to highest saline dose is shown in the table (*p ≤ 0.05, ** p = 0.008, ANOVA, compared with normal group). n

ΔR5

ΔR20

ΔfRes

ΔX5

ΔAx

Normal 85 14 (0, 34) 1 (−12, 15) 16 (7, 38) −26 (−66, −8) 66 (18, 150) BHR 12 49** (29, 61) 5 (−13, 21) 28 (−14, 76) −94* (−161, −34) 200 (31, 552) UAD 9 31* (20, 52) 13 (4, 19) 29 (10, 47) −27 (−85, 7) 140 (31, 236)

Conclusion: Characteristic changes in IOS data were identified in UAD, however there was considerable overlap with other groups yielding low specificity of IOS in detecting UAD. In line with the concept that higher frequency oscillations reveal upper airway features, R20 values tended to increase more than other measures in UAD, however its clinical utility as a diagnostic tool was not demonstrated. Key words: Upper airway dysfunction, hypertonic saline, impulse oscillometry. Nomination for Young Investigator Award: Yes. Grant Support: ANZSRS research grant. 1 AE Vertigan et al., Laryngoscope, 116:643–649, 2006

The Thoracic Society of Australia and New Zealand Annual Scientific Meeting 2014

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AO 003

THE EFFECT OF APPARATUS DEAD SPACE ON MEASUREMENTS OF VENTILATION HETEROGENEITY

AIRWAY RESPONSE TO EUCAPNIC VOLUNTARY HYPERPNEA & MANNITOL IN PULMONARY FUNCTION LAB (PFL) PATIENTS WITH SUSPECTED EXERCISE-INDUCED BRONCHOCONSTRICTION (EIB)

AVRAAM J, ELLIS M, STUART-ANDREWS C, THOMPSON B The Alfred Hospital and Monash University Background: The multibreath nitrogen washout (MBNW) test has proved a valuable tool in examining the contribution of the peripheral airways in ventilation heterogeneity. However, while the use of the MBNW technique is growing the standardisation of MBNW analysis and testing procedures have not been formally documented. Of particular concern is the effect of apparatus dead space, which has been suggested to affect measurements of Lung Clearance Index (LCI). Aim: To examine the effects of apparatus dead space on MBNW analysis. Method: FRC, Lung Clearance Index (LCI) and indices of acinar and conductive airways gas mixing (Sacin and Scond respectively) were measured in 10 healthy non-smoking adults using a custom made MBNW device with three dead space sizes (different sized Hans Rudolf valves—see table). The MBNW test was performed with the subject in the seated position while inspiring 1 L of 100% O2 at their resting respiratory rate until expired N2 concentration fell to 2%. Results: There was no statistical difference for Sacin, Scond or FRC between apparatus dead space sizes. However LCI measured with the large dead space size was significantly higher than that measured with small and medium dead space sizes (repeated measures ANOVA p = 0.008).

Small (105 mL) Medium (133 mL) Large (217 mL)

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Sacin ± SD

Scond ± SD

LCI2% ± SD

FRC ± SD

0.139 ± 0.055 0.140 ± 0.068 0.137 ± 0.047

0.019 ± 0.014 0.015 ± 0.018 0.011 ± 0.010

6.530 ± 1.507 6.426 ± 1.491 7.597 ± 1.319*

2.896 ± 0.473 3.160 ± 0.584 2.926 ± 0.637

Conclusion: We have demonstrated that apparatus dead space has a direct effect on LCI that is clinically significant. Key words: Multibreath nitrogen washout, ventilation heterogeneity, apparatus dead space, Sacin, Scond, Lung Clearance Index.

BRANNAN J1, LAKE C2, CAMPS J2, MUNOZ P2, BRIFFA P2 Westmead Hospital, 2Royal Prince Alfred Hospital

1

Aim: To investigate the prevalence of a 10% fall to mannitol in persons suspected of EIB who have also had a Eucapnic Voluntary Hyperpnea (EVH) challenge. A 10% fall in FEV1 to EVH is a more sensitive test to identify potential for EIB than mannitol where a 15% fall is required. In elite athletes who are positive to EVH, it has been suggested that the provoking dose of mannitol to cause a 10% fall in FEV1 (PD10) may predict a positive EVH challenge (Holzer et al., AJRCCM 2003:167:534–537). Method: Retrospective analysis of 42 patients attending the PFL (28 males, 24 ± 11 yrs) had both EVH & AridolTM (MANN) (Protocols see Holzer et al.). Frequency and severity of positive responses to EVH at a 10% fall FEV1 to 6 min of EVH was compared to MANN at either a 10% and 15% fall to 635 mg or less. Data are expressed as mean ± SD unless otherwise stated. Statistics assessed using Student’s t-tests. Results: EVH+ (n = 13) was identified more often with a PD10 (n = 12) than a PD15 (n = 4). Of those with a PD10; 8 EVH+/MANN+ & 4 MANN+ alone, while there were 5 EVH+ alone. BHR overall was mild. MANN+/EVH+ had similar severity of response (16 ± 5% fall FEV1, n = 8) compared to EVH+ only (13 ± 1% fall FEV1,n = 5) (p = 0.1). In those negative to both tests (i.e., no PD10) there was no difference in % fall in FEV1 to either EVH (Table) or MANN (4.8 ± 2.6% fall FEV1) (p = 0.8). Duration between tests was 23 ± 39 days. No BHR

n %Fall PD10,mg (95%CI)

BHR

EVH−/MANN−

EVH+

MANN PD10

25 4.9 ± 2.3

13 14.5 ± 4.0

12 284 (95%CI 223,362)

Conclusion: A 10% fall in FEV1 to mannitol identifies EVH+ more frequently than a 15% fall in PFL patients. However there was a smaller but similar proportion with mild airway responses who were only positive to either MANN or EVH. Key words: Eucapnic Voluntary Hyperpnea, Mannitol, EIB. Grant Support: Nil.

© 2014 The Authors Respirology © 2014 Asian Pacific Society of Respirology

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Respirology (2014) 19 (Suppl. 2), 2–6

AO 005

NATURAL DECLINE IN FEV1 AND FVC: SELF VERSUS REFERENCE EQUATIONS

IS INCREASED BRONCHOMOTOR TONE AN IMPORTANT DRIVING FACTOR IN DEVELOPING ACINAR AIRWAY ABNORMALITIES IN SMOKERS WITH NORMAL SPIROMETRY?

SWANNEY M, STANTON J, O’REILLY-NUGENT A Respiratory Physiology Laboratory, Canterbury District Health Board, Christchurch, New Zealand 8140 Introduction: Ideally, serial measures of lung function should be compared using data from the person when young and healthy. In practice reference equations are the best substitute. Aim: To compare the natural decline in spirometry in respiratory scientists using measured values and their reference value z-scores. Method: Serial measures of FEV1 and FVC from respiratory scientists who responded to a call for data were analysed. We calculated the annual decline in measured values, using the oldest data as a baseline, and compared with z-scores using ECSC/ERS’93, Hankinson and GLI2012 equations. Results: 2044 data points were available for 26 scientists (13 female) starting from 20–39 years up to 31–60 years. The data time-span was 5 to 33 years. The average fall in FEV1 was 29 mL/year and FVC 23 mL/year. Average Annual Decline in Spirometry Values

FEV1 Females Males All subjects

Change mL/year

Range mL/year

−27 −31 −29

−2 to −44 +7 to −64

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FVC

Change mL/year

Range mL/year

Females Males All subjects

−15 −30 −23

+17 to −34 +4 to −67

The z-score trends using GLI2012 equations demonstrated they virtually matched the rate of decline in FEV1 and FVC in our group of respiratory scientists. ECSC/ERS’93 elevated the z-score, and Hankinson showed a decreasing trend suggesting these equations are a poorer match for our longitudinal data. Conclusion: This study suggests that the GLI2012 equations are more appropriate for monitoring lung function over time. Key words: Spirometry, FEV1, FVC, Reference Equations.

JETMALANI K1,2, CHAPMAN D1,3, FARAH C1,2,4, BEREND N1,2, SALOME C1,2, KING G1,2,5 1 Woolcock Institute of Medical Research, 2University of Sydney, 3The Vermont lung Centre, University of Vermont, 4Department of Respiratory Medicine, Concord Hospital, NSW, 5Department of Respiratory Medicine, Royal North Shore Hospital, NSW Background: Early acinar airway abnormalities in smokers with normal spirometry could be caused by an increase in airway smooth muscle (ASM) tone due in part to cigarette smoke, its resultant inflammation, its effect on release of bronchoconstrictive mediators or its oxidant effects. Aim: To determine the contribution of cigarette smoke induced increased ASM tone to early acinar airway abnormalities by measuring their reversibility with bronchodilator (BD). Method: 49 asymptomatic smokers aged 40 (± 10) years [% FEV1 97(10.4); FEV1/FVC 0.75 (0.5)] and 15 never smokers aged 40 (± 12) years [% FEV1 107(16.1); FEV1/FVC 0.78 (0.5)] underwent measure of Sacin (small airway function in diffusion-dependent airways) by multiple breath nitrogen washout, spirometry before and 20 minutes after 200 μg salbutamol + 80 μg ipratropium bromide and DLCO at baseline. Smokers were grouped according to normal or abnormal Sacin (upper limit of normal of 0.13 L−1) at baseline. Results: 15 smokers (31%) had an abnormal Sacin despite having similar smoking histories to the normal Sacin group (19 vs. 16, respectively; p = 0.15). Spirometry and Sacin improved significantly in all three groups with BD (Table 1). BD reduced Sacin to a similar extent in both smokers groups and controls (p = 0.09), but did not normalise it in those with abnormal Sacin. In the abnormal Sacin group, Sacin correlated with DLCO (p = 0.04) and post bronchodilator Sacin correlated with pack years of smoking (p < 0.01). Conclusion: In smokers with abnormal Sacin, bronchodilator reduced but did not normalise Sacin, suggesting that ASM tone contributed to acinar airway dysfunction. The residual abnormality in Sacin related to smoking exposure, suggesting contribution from other cigarette smoke related abnormalities such as structural and/or inflammatory changes.

Table 1. Changes in spirometry and Sacin with BD

Δ p Δ p Δ p

FEV1 (L) value FEV1/FVC value Sacin (L−1) value

Abnormal Sacin Abnormal Sacin controls

Normal Sacin

Controls

0.15 (0.17) 0.001 0.31 (0.26) 0.002 −0.018 (0.02) 0.02

0.15 (0.13) 0.001 0.35 (0.27) 0.001 −0.007(0.01) 0.04

0.1 (0.1) 0.01 0.28 (0.28) 0.002 −0.009 (0.01) 0.01

Data presented as mean (SD). Key words: MBNW, Sacin, smokers, bronchodilator. Grant Support: KJ was supported by an APA.

© 2014 The Authors Respirology © 2014 Asian Pacific Society of Respirology

The Thoracic Society of Australia and New Zealand Annual Scientific Meeting 2014

AO 007

LUNG FUNCTION AND EXERCISE CAPACITY IN ADULT SURVIVORS OF VERY LOW BIRTH WEIGHT STANTON J1, EPTON M2, DARLOW B3, HORWOOD J3, MARTIN J3, SWANNEY M1 1 Christchurch Hospital, 2Department of Respiratory Medicine, Christchurch, 3 University of Otago Introduction: Little is known about pulmonary function sequelae and exercise capacity in adult survivors of very low birth weight (VLBW). A multispecialty research project in New Zealand involving a VLBW (

Abstracts of the Thoracic Society of Australia & New Zealand and the Australian & New Zealand Society of Respiratory Science 2014 Annual Scientific Meetings, 4-9 April 2014, Adelaide, SA.

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