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BACKGROUND Although deep inspiratory breath-hold (DIBH) is routinely used for left-sided breast cancers, its benefits for right-sided breast cancer (rBC) have yet to be established. We compared free-breathing (FB) and DIBH treatment plans for a cohort of rBC undergoing regional nodal irradiation (RNI) to determine its potential benefits. METHODS AND MATERIALS rBC patients considered for RNI (internal mammary nodal chains, supraclavicular field, with or without axilla) from October 2017 to May 2020 were included in this analysis. For each patient, FB versus DIBH plans were generated and dose volume histograms evaluated the following parameters: mean lung dose, ipsilateral lung V20/V5 (volumes of lung receiving 20 Gy and 5 Gy, respectively); mean heart dose and heart V5 (volumes of heart receiving 5 Gy); liver V20 absolute /V30 absolute (absolute volume of liver receiving 20 Gy and 30 Gy, respectively), liver Dmax, and total liver volume irradiated (TVIliver). The dosimetric parameters were compared using Wilcoxon signed-rank testing. RESULTS Fifty-four patients were eligible for analysis, comparing 108 FB and DIBH plans. DIBH significantly decreased all lung and liver parameters: mean lung dose (19.7 Gy-16.2 Gy, P < .001), lung V20 (40.7%-31.7%, P < .001), lung V5 (61.2%-54.5%, P < .001), TVIliver (1446 cc vs 1264 cc; P = .006) liver Dmax (50.2 Gy vs 48.9 Gy; P = .023), liver V20 (78.8-23.9 cc, P < .001), and liver V30 (58.1-14.6 cc, P < .001) compared with FB. DIBH use did not significantly improve heart parameters, although the V5Heart trended on significance (1.25-0.6, P = .067). CONCLUSIONS This is the largest cohort to date analyzing DIBH for RNI-rBC. Our findings demonstrate significant improvement in all lung and liver parameters with DIBH, supporting its routine consideration for rBC patients undergoing comprehensive RNI.

Background Using a breath sound analyzer, we investigated clinical parameters for detecting bronchial reversibility in infants. Methods A total of 59 infants (4–39 months, mean age 7.8 months) were included. In Study 1 , the intra- and inter-observer variability was measured in 23 of 59 infants. Breath sound parameters, the frequency at 99% of the maximum frequency ( F 99 ), frequency at 25%, 50%, and 75% of the power spectrum (Q 25 , Q 50 , and Q 75 ), and highest frequency of inspiratory breath sounds (HFI), and parameters obtained using the ratio of parameters, i.e. spectrum curve indices, the ratio of the third and fourth area to total area ( A 3 / A T and B 4 / A T , respectively) and ratio of power and frequency at F 75 and F 50 (RPF 75 and RPF 50 ), were calculated. In Study 2 , the relationship between parameters of breath sounds and age and stature were studied. In Study 3 , breath sounds were studied before and after β 2 agonist inhalation. Results In Study 1 , the data showed statistical intra- and inter-observer reliability in A 3 / A T ( p =0.042 and 0.034, respectively) and RPF 50 ( p =0.001 and 0.001, respectively). In Study 2 , there were no significant relationships between age, height, weight, and BMI. In Study 3 , A 3 / A T and RPF 50 significantly changed after β 2 agonist inhalation ( p =0.001 and p Conclusions Breath sound analysis can be performed in infants, as in older children, and the spectrum curve indices are not significantly affected by age-related factors. These sound parameters may play a role in the assessment of bronchial reversibility in infants.

To compare heart and lung doses for adjuvant whole breast irradiation (WBI) between radiation plans generated supine with deep inspiratory breath hold (S-DIBH) and prone with free-breathing (P-FB) and examine the effect of breast volume (BV) on dosimetric parameters.Patients with left breast ductal carcinoma in situ or invasive cancer receiving adjuvant WBI were enrolled on a single-institutional prospective protocol. Patients were simulated S-DIBH and P-FB; plans were generated using both scans. Wilcoxon signed-rank and rank-sum tests were used to compare intrapatient differences between plans for the entire cohort and within BV groups defined by tertiles.Forty patients were enrolled. Thirty-four patients are included in the analysis owing to patient withdrawal or inability to hold breath. With WBI dose of 4005 to 4256 cGy, mean heart dose (MHD) was 80 cGy in S-DIBH and 77 cGy in P-FB (P = .08). Mean ipsilateral lung dose (MLD) was 453 cGy in S-DIBH and 45 cGy in P-FB (P.0001). Mean and max left anterior descending artery doses were 251 cGy and 551 cGy in S-DIBH, respectively (P = .1), and 324 cGy and 993 cGy in P-FB, respectively (P = .3). Hot spot and separation were 109% and 22 cm in S-DIBH, respectively, and 107% and 16 cm in P-FB, respectively (P.0001). For patients with smallest BV, S-DIBH improved MHD and left anterior descending artery doses; for those with largest BV, P-FB improved cardiac dosimetry. With increasing BV, there was an increasing advantage of P-FB for MHD (P = .05), and max (P = .03) and mean (P = .02) left anterior descending artery doses, and the reduction in MLD, hot spot, and separation with P-FB increased (P .05).MHD did not differ between P-FB and S-DIBH, whereas MLD was significantly lower with P-FB. Analysis according to breast volume revealed improved cardiac dosimetry with S-DIBH for women with smallest BV and improved cardiac dosimetry with P-FB for women with larger BV, thereby providing a dosimetric rationale for using breast size to help determine the optimal positioning for WBI.

Gas diffusion and transcapillary exchange take place in the microvasculature. Therefore, the evaluation of skin blood flow regulation and functional capacities of the microcirculatory system at various ontogenesis stages is of great importance. Using laser Doppler flowmetry in the group of boys (n = 15) and girls (n = 13) of 8 and 10 years of age, skin microcirculation and its regulatory mechanisms were evaluated. The study found an increase in the perfusion index in children between the age of 8 and 10 induced by the shifting roles of mechanisms of the microcirculatory regulation. The comparison of basal microcirculatory parameters did not display statistically significant differences related to sex in 8and 10-year old participants. However, almost equal perfusion in boys and girls was maintained by different contributions of regulatory mechanisms. The breath holding test showed an increase in the initial microcirculation index and capillary blood flow reserve in the group of 10-year-old boys and girls. Our study revealed differences in various microcirculation parameters, in the intensity of active and passive rhythms of blood flow oscillations and response to inspiratory breath hold, which indicates age-related transformations of microcirculation system., В микроциркуляторном русле осуществляются процессы диффузии газов и транскапиллярный обмен. В связи с этим актуальной задачей является оценка состояния регуляции кровоснабжения кожи и функциональных возможностей системы микроциркуляции крови на отдельных этапах онтогенеза. С помощью метода лазерной допплеровской флоуметрии в группе мальчиков (n = 15) и девочек (n = 13) по достижении ими возрастов 8 и 10 лет оценивали состояние кожной микроциркуляции и функционирование механизмов ее регуляции. Обнаружено увеличение показателя микроциркуляции в возрастном периоде от 8 до 10 лет, вызванное перераспределением механизмов регуляции микрокровотока. При сравнении базальных показателей микроциркуляции достоверных половых различий в возрастах 8 и 10 лет не выявлено, однако поддержание примерно равного уровня перфузии у мальчиков и девочек достигается при разном соотношении регуляторных влияний на микрокровоток. При проведении дыхательной пробы выявлено увеличение исходного показателя микроциркуляции и резерва капиллярного кровотока в группе мальчиков и девочек в возрасте 10 лет. В ходе проведенного исследования между детьми 8и 10-летнего возраста выявлены различия в показателях микроциркуляции, в степени выраженности активных и пассивных ритмов колебаний кровотока и реакции на дыхательную пробу, что свидетельствует о возрастных преобразованиях системы микроциркуляции.

Introduction and Objective: In adjuvant radiotherapy for left breast cancer, a significant heart volume may be included in the radiation field leading to long-term cardiac toxicities. Deep inspiratory breath hold technique (DIBH) leads to chest wall separation away from the heart and thus can reduce the heart dose compared to free breathing technique. The aim of this study is to correlate dosimetrically the degree of chest wall expansion measured on planning 4D-CT scan to the heart dose in left breast cancer irradiation using DIBH technique. Materials and Methods: Thirty four patients with left breast cancer planned for adjuvant radiotherapy were included. All patients were scanned by Varian RPM (Real Time Position Managment) respiratory gating system using infrared reflecting markers and a video camera to detect the respiratory motion. IMRT or VMAT plans were done for all patients with a prescribed dose 50Gy/25fr/5w with or without operative bed boost dose 10Gy/5fr/1w. The degree of chest wall expansion was identified by measuring the amplitude of DIBH breathing curve from baseline in planning 4D-CT scan in centimeters. The depth of expansion was correlated dosimetrically with the heart V20, V30, and mean heartdose. Results: The mean distance of chest wall expansion was 2.9cm. The mean left lung dose was 8.6Gy. The mean left lung V20 was 13.8%. The mean heart dose was 1.8Gy. The mean heart V30 was 0.6%. A statistically significant reduction of the mean heart dose and V30 was observed with chest wall expansion of 1.4cm or higher (pConclusion: In DIBH technique, the depth of chest wall expansion in 4DCT planning is dosimetrically correlated with the cardiac dose reduction during adjuvant irradiation of left breast cancer. Further clinical studies are needed to translate this dosimetric advantage into clinical benefit.

Excellent survival has been reported after combined modality treatment in bulky mediastinal Hodgkin's lymphoma. Late effects such as cardiac morbidity and secondary cancers have been reported after radiotherapy (RT), especially in young adults. Advanced RT techniques such as deep inspiratory breath-hold (DIBH), intensity-modulated RT (IMRT), and volumetric arc therapy have been used recently to reduce these late effects with encouraging results. We hereby present a case report evaluating combined effect of DIBH and IMRT in a young adult with mediastinal lymphoma.

AimDeep inspiratory breath hold (DIBH) during left-breast irradiation helps to minimise cardiac irradiation by physically separating the heart from the left breast. The dose to organs-at-risk in intensity-modulated radiotherapy (IMRT) and opposed tangent three-dimensional conformal radiotherapy (3DCRT) during DIBH in patients with left-sided breast cancer was compared.Materials and methodsA total of 20 consecutive patients with left-sided breast cancer had a computed tomography scan utilising DIBH. Mean volumes of the heart, left anterior descending coronary artery, total lung and right breast receiving 5–95% of the prescription dose were calculated.ResultsTarget volume homogeneity was improved with IMRT and average mean dose to target was higher for 3DCRT (51·03 Gy) compared with IMRT (50·47 Gy, ppppFindingsUnder DIBH, absolute differences between 3DCRT and IMRT were minimal. 3DCRT under DIBH provided excellent dosimetric results in most patients with left-sided breast cancer without the need for IMRT.

Purpose HeartWare HVAD flow waveforms provide important clinical information on pump function and patient hemodynamics. We assessed changes in flow waveform during inspiratory breath-hold (IBH) maneuver and whether optimization in device speed and medical therapy improved waveform characteristics. Methods We studied HeartWare HVAD patients at consecutive follow-up visits. Characteristic changes in the HVAD monitor flow waveform with IBH were assessed and compared to baseline for reduced flow waveform pulsatility (RWP); flatline (FL); and suction (S). If suction was induced, management was changed by reduction in pump speed, diuretics or anti-hypertensives. Average flow, peak and trough pump flows, flow pulsatility (peak - trough), speed and power were recorded. Baseline pump parameters were compared between patients who required a change (C) vs no change (NC) in management. Patients in the C group were further assessed post-management change (PC) at next visit. Results Sixteen patients were included: 13 male (81.25%), median age 53.7 years (range 38.7-75.6), median support duration 254 days (range 21-2540). Suction was observed with IBH in 6 (37.5%, group C) vs no suction in n=10 (62.5%, group NC). There was no significant difference in any baseline pump parameter between C vs NC (Table). Of the 6 patients in group C who underwent management change, 4 had pump speed reduction and 2 decreased diuretic medications. Pump speed was significantly lower in the PC group (2533 ± 81.6 vs 2600 ± 63.2 respectively, p=0.025) at follow up. No other significant differences in pump parameters were noted (Table). At follow up (PC) there were significantly fewer waveform abnormalities (including RWP, FL, or S) 0.94 ± 0.90 vs 2.4 ± 0.5, p=0.034. Conclusion Pump parameters and flow waveform observation at rest do not reflect suction risk in stable HVAD outpatients. IBH is a simple clinical intervention to assess suction risk threshold and can be utilized to guide changes in management.

Volitional Apnea produces a robust peak sympathetic response through several interacting mechanisms. However, the specific contribution of each mechanism has not been elucidated. Muscle sympathetic activity was collected in participants (n = 10; 24 ± 3 years) that performed four maximal volitional apneas aimed at isolating lung‐stretch (mechanical) and chemoreflex drive: (Ainslie and Duffin 2009) end‐expiratory breath‐hold, (Ainslie et al. 2013) end‐inspiratory breath‐hold, (Alpher et al. 1986) prehyperventilation breath‐hold, and (Andersson and Schagatay 1998) prehyperoxia breath‐hold. A final repeated rebreathe breath‐hold protocol was performed to measure the peak sympathetic response during successive breath‐holds at increasing chemoreflex stress. Finally, the influence of dynamic ventilation was assessed through asphyxic rebreathe. Muscle sympathetic activity was calculated as the change in burst frequency (burst/min), burst incidence (burst/100 heart‐beats), and amplitude (au) between baseline and prevolitional breakpoint. Rebreathe was analyzed at similar chemoreflex stress as inspiratory breath‐hold. All maneuvers increased muscle sympathetic activity compared to baseline (P

Real-time measurement of propofol in the breath may be used for routine clinical monitoring. However, this requires unequivocal identification of the expiratory phase of the respiratory propofol signal as only expiratory propofol reflects propofol blood concentrations. Determination of CO2 breath concentrations is the current gold standard for the identification of expiratory gas but usually requires additional equipment. Human breath also contains isoprene, a volatile organic compound with low inspiratory breath concentration and an expiratory concentration plateau. We investigated whether breath isoprene could be used similarly to CO2 to identify the expiratory fraction of the propofol breath signal. We investigated real-time breath data obtained from 40 study subjects during routine anesthesia. Propofol, isoprene, and CO2 breath concentrations were determined by a combined ion molecule reaction/electron impact mass spectrometry system. The expiratory propofol signal was identified according to breath CO2 and isoprene concentrations and presented as median of intervals of 30 s duration. Bland-Altman analysis was applied to detect differences (bias) in the expiratory propofol signal extracted by the two identification methods. We investigated propofol signals in a total of 3,590 observation intervals of 30 s duration in the 40 study subjects. In 51.4 % of the intervals (1,844/3,590) both methods extracted the same results for expiratory propofol signal. Overall bias between the two data extraction methods was -0.12 ppb. The lower and the upper limits of the 95 % CI were -0.69 and 0.45 ppb. Determination of isoprene breath concentrations allows the identification of the expiratory propofol signal during real-time breath monitoring.

PURPOSE Deep-inspiratory breath-hold (DIBrH) Tc-99m-macroaggregated albumin (MAA) SPECT images were developed to accurately evaluate perfusion impairment in smokers' lungs. METHODS DIBrH SPECT was performed in 28 smokers with or without low attenuation areas (LAA) on CT images, using a triple-headed SPECT system and a laser light respiratory tracking device. DIBrH SPECT images were reconstructed from every 4 degrees projection of five adequate 360 degrees projection data sets with almost the same respiratory dimension at 20 sec DIBrH. Perfusion defect clarity was assessed by the lesion (defect)-to-contralateral normal lung count ratios (L/N ratios). Perfusion inhomogeneity was assessed by the coefficient of variation (CV) values of pixel counts and correlated with the diffusing capacity of the lungs for carbon monoxide/alveolar volume (DLCO/VA) ratios. The results were compared with those on conventional images. RESULTS Five DIBrH projection data sets with minimal dimension differences of 2.9+/-0.6 mm were obtained in all subjects. DIBrH images enhanced perfusion defects compared with conventional images, with significantly higher L/N ratios (P

Introduction: Different techniques of radiation therapy have been studied to reduce the cardiac dose in left breast cancer. Aim: In this prospective dosimetric study, the doses to heart as well as other organs at risk (OAR) were compared between free-breathing (FB) and deep inspiratory breath hold (DIBH) techniques in intensity modulated radiotherapy (IMRT) and opposed-tangent three-dimensional radiotherapy (3DCRT) plans. Materials and Methods: Fifteen patients with left-sided breast cancer underwent computed tomography simulation and images were obtained in both FB and DIBH. Radiotherapy plans were generated with 3DCRT and IMRT techniques in FB and DIBH images in each patient. Target coverage, conformity index, homogeneity index, and mean dose to heart (Heart Dmean), left lung, left anterior descending artery (LAD) and right breast were compared between the four plans using the Wilcoxon signed rank test. Results: Target coverage was adequate with both 3DCRT and IMRT plans, but IMRT plans showed better conformity and homogeneity. A statistically significant dose reduction of all OARs was found with DIBH. 3DCRTDIBH decreased the Heart Dmean by 53.5% (7.1 vs. 3.3 Gy) and mean dose to LAD by 28% compared to 3DCRTFB. IMRT further lowered mean LAD dose by 18%. Heart Dmean was lower with 3DCRTDIBH over IMRTDIBH (3.3 vs. 10.2 Gy). Mean dose to the contralateral breast was also lower with 3DCRT over IMRT (0.32 vs. 3.35 Gy). Mean dose and the V20 of ipsilateral lung were lower with 3DCRTDIBH over IMRTDIBH (13.78 vs. 18.9 Gy) and (25.16 vs. 32.95%), respectively. Conclusions: 3DCRTDIBH provided excellent dosimetric results in patients with left-sided breast cancer without the need for IMRT.

A breath sound analyser was used to detect bronchoconstriction without wheezing during methacholine inhalation challenge in children. The highest frequency of inspiratory breath sounds increased significantly during bronchoconstriction and decreased after inhalation of a bronchodilator. The highest frequency of inspiratory breaths sounds was correlated with bronchial reactivity. Background and objective: It is difficult for clinicians to identify changes in breath sounds caused by bronchoconstriction when wheezing is not audible. A breath sound analyser can identify changes in the frequency of breath sounds caused by bronchoconstriction. The present study aimed to identify the changes in the frequency of breath sounds during bronchoconstriction and bronchodilatation using a breath sound analyser. Methods: Thirty-six children (8.2 ± 3.7 years; males : females, 22 : 14) underwent spirometry, methacholine inhalation challenge and breath sound analysis. Methacholine inhalation challenge was performed and baseline respiratory resistance, minimum dose of methacholine (bronchial sensitivity) and speed of bronchoconstriction in response to methacholine (Sm: bronchial reactivity) were calculated. The highest frequency of inspiratory breath sounds (HFI), the highest frequency of expiratory breath sounds (HFE) and the percentage change in HFI and HFE were determined. The HFI and HFE were compared before methacholine inhalation (pre-HFI and pre-HFE), when respiratory resistance reached double the baseline value (max HFI and max HFE), and after bronchodilator inhalation (post-HFI and post-HFE). Results: Breath sounds increased during methacholine-induced bronchoconstriction. Max HFI was significantly greater than pre-HFI (P

Study design: This was an observational, descriptive case-series study. The magnitude and direction of diaphragm movement during tidal and maximal inspiratory breaths in tetraplegic subjects were measured using B-mode sonography on a single occasion. Data were tabulated for descriptive analysis. Objective :There is a paucity of literature reporting dynamic movements of the paralyzed diaphragm. The aim of this pilot study was to investigate and record diaphragm movement in subjects with a cervical spinal cord injury (C1–C5), which had resulted in tetraplegia with partial or complete diaphragm paralysis. Subjects were patients of the Royal Adelaide Hospital in South Australia. Results: Three subjects participated in the study. The magnitude of diaphragm movement was small in two subjects and approached normal in one subject. During tidal inspiratory and maximal inspiratory breaths, the diaphragm moved in a caudal direction in two subjects. In the other subject, the diaphragm moved in a cephalad direction during a maximal inspiratory breath. Conclusion: Imaging of diaphragm movement was well tolerated by three subjects with cervical spinal cord injury. The difference in magnitude of diaphragm movement was not fully explained by the level of injury and the American Spinal Injury Association classification. Refereed/Peer-reviewed

A 31-year-old woman was referred to chest clinic with an 18-month history of cough, breathlessness and weight loss. She had previously been treated unsuccessfully with bronchodilators. In clinic she was found to have vocal hoarseness and harsh, monophonic inspiratory breath sounds. A bronchoscopy was arranged, but the patient was found dead before it could be performed. A postmortem examination with histology found evidence of active and chronic inflammation as well as destruction of cartilage, in keeping with a diagnosis of relapsing tracheobronchial polychonditis.

Therapeutic aerosols are routinely used in the management of infant obstructive airways disease. Infants often become distressed during administration. The aim of this study was to determine the influence of distress and disease severity on the absorption of aerosolised drug in this age group.Fifteen infants, eight with resolving chronic lung disease of prematurity (mean age, 13 months), and seven infants with normal birth histories (mean age, 11 months) were studied. Flow through small airways was assessed by measurement of partial forced expiratory flow volume curves. Each infant was then given a dose of 20 mg nebulised sodium cromoglicate via a Sidestream nebuliser and distress was graded as: 1, not distressed; 2, distressed. Infants were excluded if contact with the mask was lost for more than 10 seconds. Urine was collected for eight hours and analysed for excreted drug by radioimmunoassay.Sodium cromoglicate is absorbed by the respiratory epithelium, and undergoes renal (43%) and hepatic (57%) excretion. A mean of 0.43% of the total nebulised drug dose was excreted in the urine of the non-distressed infants compared with 0.11% of total dose in the distressed infants. Flow through the small airways was significantly reduced in infants with chronic lung disease of prematurity. Maximum flow at functional residual capacity did not correlate with the amount of drug in the urine, but the degree of distress did.To maximise absorption, nebulised drugs should be given to settled infants. The degree of airways disease does not influence drug absorption in this age group.

Objectives This study examined contributions of deep inspiratory breath hold (DIBH) -FDG-PET/CT to clinical assessment of ILD in collagen diseases. Methods We assessed ILD in 45 patients with collagen diseases including 6 RA, 9 SSc, and 17 DM/PM by using DIBHPET/CT. Distribution of positive signals was evaluated in the upper slice 2cm above the tracheal bifurcation, the middle slice 1 cm below the bifurcation, and the lower slice 2 cm above the right diaphragm. Individual slices were further divided into 6 regions. Visual score was determined by numbers of positive signal lesions in total 18 regions. Results Abnormal accumulation of FDG was found in the active ILD lesions which were concordant with nodular, reticular, consolidative shadows and ground glass opacity illustrated by plain CT scan. The visual score in the lesions was well correlated with serum levels of KL-6 (Pearson ρ=0.571, P=0.011) and CRP (Spearman ρ=0.506, P=0.016). The value was significantly higher in 26 patients who were judged as being clinically active than the other 19 patients. Of 24 patients who had follow-up examinations, abnormal FDG accumulation was reduced in response to the therapies in 11 patients, whereas the findings were unchanged or deteriorated in the remaining 13 patients who had stable or progressive ILD. In spite of no interval change in plain CT scan, PET/CT detected significant changes of FDG intensity in the follow-up studies in 5 patients. FDG signal was reduced in 4 of them, whereas it was increased in one patient. Conclusions In summary, DIBH PET/CT is useful for monitoring of activity in collagen disease associated ILD. Disclosure of Interest None Declared

Clinicians who auscultate the chest of normal children note that the frequency content of their breath sounds appears to vary with age. Because these changes have not been systematically documented before, we recorded and analyzed inspiratory breath sounds in 35 children (0 to 13 years) and five adults (34 to 43 years). Our objective was to determine if the frequency content of normal breath sounds differed with age. Using a Fast Fourier Transform program, we calculated an average amplitude frequency spectrum from the inspiratory portion of the breath sounds of each subject (n = 10 breaths), and we compared the shape of the AFS and the values of selected frequency parameters. We found that the shape of the AFS of the youngest children differed most from the AFS of adults. Three of four selected frequency parameters (F25, F50, F95) differed significantly between children and adults (p less than 0.05), and one parameter (F75) did not (p = 0.11). The F25, F50, and F75 parameters of children (but not F95) were correlated (p less than 0.001) with increasing height and age. These results suggest that differences in the frequency content of the normal breath sounds of children and adults contribute to the differences that clinicians detect during clinical auscultation.

Results: 1. The average tumor motion in the entire cohort was 1.54-cm (range 0.7-1.9) in the cephalo-caudad directions, 1.26-cm(range 0.1-3.9) in the antero-posterior directions, and 0.56-cm ( range 0-1.1) in the lateral directions between maximal inspiration and maximal expiration. 2. All plans provided excellent tumor coverage with comparable EUD values for a prescription of 60Gy in 30 fractions of 2Gy; minimum 90% coverage. 3. Cord dose was kept below tolerance in all plans without significant compromise in BTV margins. 4. The dose to the esophagus was similarly not compromised with an NTDmean average of 13.8 Gy (1.0-36.9) 5. MIBH produced superior lung sparing evidenced by lower V20, mean lung dose, and NTDmean values. The average NTDmean for all plans was 20.5 Gy in FB and 14.3 Gy in MIBH. For standard plans (Trial 1, Table 1), the NTDmean values were 21.8 Gy (FB) and 15.4 Gy (MIBH), corresponding to a projected risk of grade 2 pneumonitis of 21% an d8%a t 6months, respectively (1). The NTDmean values for gated treatment plans (Trial 3, Table 1) were 19.3 Gy(FB) and 12.8 Gy (MIBH), corresponding to a 19% and 5% projected risk of pneumonitis at 6 months, respectively. Tomotherapy plans resulted in further improvement in lung DVHs, NTDmean, and a decrease in projected pneumonitis rates. Conclusions: If a 20% risk of Grade 2 pneumonitis is acceptable, the dose to standard expansion volumes can be escalated by a factor of 1.4 using MIBH; using gated delivery techniques dose can be escalated by a factor of 1.7. Tomotherapy enhances this factor still further. Previous studies have demonstrated that dose levels of 85 Gy are required to achieve 50% local control (2). MIBH, using narrow margins with the utilization of IMRT, should allow dose escalation up to and beyond 85Gy.

The British guidelines on asthma management and other recent reviews have widely advocated the use of spacer devices for asthmatic patients.1-3 Spacer devices allow aerosol to be inhaled through a valved mouthpiece during a single inspiratory breath or as is often recommended for children during tidal breathing.2During the expiratory phase of a tidal breathing manoeuvre the valve closes. Although this action prevents leakage of aerosol from the spacer and ingress of moisture into the holding chamber, there is an inevitable increase in the expiratory resistance. We have measured the resistance …

Estimation of cardiac output by impedance cardiography (QZ) in exercise during normal breathing (NB) has been limited by motion artifact. Our objective was to obtain readable impedance cardiograms on five subjects during upright cycle exercise at 0, 50, 100, 150, and 200 W to permit comparisons of QZ during NB, expiratory breath hold (EXP) and inspiratory breath hold (INSP). Q was also determined using an equilibration CO2 rebreathing method [Q(RB)]. QZ during NB exceeded EXP QZ at 100, 150, and 200 W, and exceeded INSP QZ at 100 W (P less than 0.05). The low EXP QZ values were due to a significantly lower stroke volume at 100, 150, and 200 W (P less than 0.05). For the INSP QZ at 100 W, heart rate was lower than during EXP (P less than 0.05). Regression of QZ (NB) against Q(RB) resulted in a linear relationship (r = 0.93) over the range of Q = 7–26 1/min. The slope of the regression differed significantly from 1.0 (P less than 0.05). We conclude that QZ values obtained during EXP or INSP should not be assumed to represent QZ during NB, at least at work rates greater than 50 W. A consequence of the linear relationship between QZ(NB) and Q(RB) over the range of 0–200 W is that estimates of CO2 rebreathing cardiac output can be obtained by impedance cardiography if QZ is adjusted using an appropriate empirical factor.

Summary The intenity of the stethoscopic inspiratory breath sounds and regional ventilation were compared in 47 patients with pulmonary emphysema. Two observers used a four grade scale for recording the breath sounds. Weak or absent breath sounds were found to be accompanied by poor ventilation. There was remarkably good agreement between observers.

To develop a pediatric predictor index (PPI) for the outcome of emergency management of acute asthma, 156 children were studied prospectively and grouped by outcome. Of 193 episodes, 130 (67.4%) resulted in successful treatment, 39 (20.2%) in relapse, and 24 (12.4%) in admission. Measured and observed variables from before and after initial therapy were analyzed for the three groups. There were no significant differences between the relapse and successful treatment groups, which were combined for analysis and termed the discharge group. Significant differences were noted between the admission and discharge groups only for dyspnea before and after therapy, accessory muscle use, inspiratory breath sounds and wheezing, and post-respiratory rates, but not for pulse or peak expiratory flow rates before or after therapy. The PPI was determined with multivariate logistic regression and is calculated using the following variables: inspiratory breath sounds, wheezing, and respiratory rates. A score of 0 correctly categorized 95% of admissions, but incorrectly categorized 34% of those discharged. Despite low specificity and limited usefulness as early predictors of admission, PPI variables may serve as valuable adjuncts to the physician in determining the outcome of acute asthma in children.

To the Editor:— Although there are no pathognomonic physical signs of pulmonary cavitation, auscultation of the chest over a cavity is frequently rewarding. A unique sequence of sounds is superimposed on the vesicular or bronchovesicular inspiratory breath sounds. One rale, or a small group of medium or coarse rales, is heard, usually in the early part of the middle third of inspiration. Tubular or cavitary breath sounds begin with the rales. The pitch of the tubular breath sounds varies with the size of the cavity and the depth and speed of inspiration. These sounds are almost identical to the sounds produced by blowing up a balloon. The balloon is partially inflated, and the neck of the balloon is pinched between the fingers to prevent the escape of air. After the balloon is put to the lips the neck is released. There is sufficient moisture in the neck of the balloon