Pulmonary function testing in veterinary practice

Reference values for dogs regarding tidal breathing flow volume loop (TBFVL) parameters are scarce in the veterinary literature, so each new study requires a healthy reference population to be studied simultaneously with the diseased one. To establish reference values for TBFVL parameters in healthy dogs, to detect any potential variability in loop shape and in various TBFVL parameters and to propose clinically useful parameters for TBFVL analysis. Cross-sectional, prospective study. Twenty-one healthy, unsedated, untrained, young adult, male Beagle dogs, with minimum variability in body weight and somatometry were used. Their good health status was confirmed by physical examination, complete blood count, serum biochemistry, urinalysis, serology and parasitology for Dirofilaria immitis, faecal examination, arterial blood gas analysis, electrocardiography, and radiographic and endoscopic examinations of the respiratory tract. The shape of the TBFVLs was assessed initially. Volume, time and flow parameters, as well as their ratios, were calculated; in total 44 parameters were evaluated. Statistical indices, including Cronbach's α, discrimination index, coefficient of variation (CV) and 95% confidence intervals were estimated for each parameter. One consistently reproducible type of TBFVL shape was identified that had a similar appearance to the letter D. Statistical analysis showed that only two parameters were found to have Cronbach's α lower than 0.80. The CV for the TBFVL parameters ranged from 1.5% to 49%, but the vast majority had values lower than 20%. Eight parameters had very low CV, indicating increased homogeneity. A large number of clinically applicable TBFVL parameters were identified. Parameters related to flow and time were considered to correlate more objectively to the functional capacity of the respiratory system of healthy, unsedated dogs.

SUMMARY A modified castellated laryngofissure procedure (castellated laryngofissure, vocal fold resection, and bilateral arytenoid lateralization) was performed on 12 dogs with bilateral laryngeal paralysis. Clinical signs of airway obstruction were assessed and a pulmonary function test (tidal breathing flow volume loop) was used to evaluate the severity of obstruction. The dogs were evaluated before surgery and at various periods from 4 days to 15 months after surgery. One dog died immediately after surgery and 3 dogs died due to nonrelated or unknown causes 1, 9, and 11 months after surgery. Clinical signs of upper airway obstruction disappeared or decreased in severity in the 11 dogs that recovered from surgery. Tidal breathing flow volume loop values were normal in 7 of 10 dogs evaluated within 5 to 189 days after surgery. The modified castellated laryngofissure procedure provided successful long-term relief of upper airway obstruction associated with bilateral laryngeal paralysis.

Respiratory monitoring: Arterial blood gas analysis, pulse oximetry, and end-tidal carbon dioxide analysis

Usefulness of the forced oscillation technique in assessing the therapeutic result of tracheobronchial central airway obstruction.

Introduction: Arterial blood gas (ABG) analysis is the gold standard method and frequently performed intervention to evaluate acid-base status along with adequacy of ventilation and oxygenation among patients with predominantly critical / acute diseases. Aims And Objectives: The aim of this study is to evaluate the correlation of VBG analysis and pulse oximetry (SpO2) with ABG analysis in critically ill patients. Materials And Methods:Intensive Care Unit (ICU), Command Hospital (Eastern Command), Kolkata, Adult patients requiring arterial blood gas analysis, JAN 2018 –JUNE 2019, 100 critically ill patients and Age – 18yrs and older, Sex – Either sex. Conclusion: In this study population of critically ill patients, pH and pCO2 on VBG analysis correlated with pH and pCO2 on ABG analysis. The SpO2 correlated well with pO2 on ABG analysis

Respiratory insufficiency is a leading cause of death in individuals with osteogenesis imperfecta (OI). However, evaluating pulmonary function in OI presents challenges. Commonly used pulmonary function tests such as spirometry and body plethysmography are sometimes difficult to perform for OI patients, and reference intervals are not always applicable. The forced oscillation technique (FOT) is a patient-friendly method for detecting respiratory abnormalities that requires no effort from the patient. This study investigates the feasibility of FOT in the evaluation of respiratory function in the clinical management of OI patients. Twelve OI patients, comprising eight with Sillence OI I, two with OI IV, and two with OI III, underwent spirometry, body plethysmography, and FOT, both pre-and post-administration of salbutamol. FOT measurements exhibited consistent trends that aligned with spirometry and body plethysmography findings. The resistance at 8 Hz decreased after the administration of salbutamol, indicating that FOT is able to detect bronchial obstruction and its alleviation by medication (p < 0.05). The resonant frequency during expiration was higher than during inspiration in nearly all patients, suggesting obstructive disease. The technique gives insight into both inspiratory and expiratory impairment of pulmonary ventilation. The main FOT parameters showed a relatively high repeatability in duplicate measurements. Bronchial obstruction can be detected by FOT in patients with OI during quiet breathing, making it an easily executable alternative to other lung function measurements. The technique can detect the bronchodilator effect of sympathomimetic medication. It has the potential to provide information on expiratory flow limitation, pulmonary restriction, and reduced lung compliance.

IntroductionAcute respiratory infections (ARIs) in infancy may have a long-term impact on the developing respiratory system. We planned a prospective cohort study to determine the impact of ARI during infancy...

Évolution du résultat des explorations fonctionnelles respiratoires chez les enfants atteints de dysplasie bronchopulmonaire

To the Editor:-The editorial by Dr. Talke [1] enthuses about the future role in man of [Greek small letter alpha]2-agonist-mediatedsedation with easy reversibility after atipamezole administration. He rightly emphasizes the future role of "a new subtype-specific [Greek small letter alpha]2agonist with sedative but not vasoconstrictor effects [italics added]." Scheinen et al. [2] briefly allude to the use of [Greek small letter alpha]2-adrenoreceptoragonists and antagonists in veterinary practice. We would point out that [Greek small letter alpha]2-adrenoreceptoragonists, such as xylazine, have been widely used in veterinary and anesthetic practice for 29 yr, and detomidine, [3] medetomidine, and atipamezole have been used for 10 yr. Some years ago we [3] showed severe cardiovascular changes and bradycardia in horses and, during a similar time period, it has been known that in sheep there is a sudden profound decrease in arterial oxygen pressure (PaO(2)) after xylazine administration. Until recently, the explanation for this has been obscure. However, we [4] and others [5] have shown extensive pulmonary edema after xylazine sedation in sheep. In our animals, PaO(2) breathing air decreased from 97.9 +/- 6.7 mmHg +/- SEM to 38.1 +/- 3.2 mmHg +/- SEM immediately after xylazine administration. All our animals had extensive pulmonary edema and microvascular congestion with erythrocytes extravasated into the alveolar space.We interpreted this as a consequence of pulmonary venospasm, there being no evidence of acute inflammation in the lung, no sign of platelet emboli, and no evidence of free radical release. There are wide species differences in the effect of xylazine on pulmonary function, but it is worth bearing in mind the potency of the vascular effects of some of these [Greek small letter alpha]2-agonistsedatives in humans and animals. The different receptor subtypes in the cardiovascular and central nervous systems must obviously be carefully investigated before we can enthuse about the inclusion of new [Greek small letter alpha]2-receptoragents in human clinical practice.J. Gareth Jones, M.D., F.R.C.P., F.R.C.A.Professor of Anaesthesia; Department of Anaesthesia; Cambridge University; Addenbrooke's Hospital; Cambridge, United KingdomPolly M. Taylor, Ph.D.Lecturer in Veterinary Anaesthesia; The Queen's Veterinary School Hospital; Cambridge, United Kingdom(Accepted for publication January 13, 1999.)

Objective To assess the effect of external diaphragm pacing on pulmonary ventilation, arterial blood gas, exercise tolerance, and quality of life in patients with stable chronic obstructive pulmonary disease(COPD). Methods Screening out 34 patients with stable COPD who had been diagnosed in the Hunan Provincial People′s Hospital from January 2017 to February 2018 and who had been in stable condition and who had been prescribed according to the GOLD 2017 COPD Guidelines.Subgroups were divided according to the GOLD 2017 COPD Guideline Pulmonary Function Grading Criteria and Comprehensive Assessment Grouping criteria, all of which were treated with 20-day in external diaphragm pacing.Before and after external diaphragm pacing treatment, chronic obstructive pulmonary disease assessment test(CAT) scores and improved British Medical Research Council Breathing Difficulties Scale (mMRC) scores, pulmonary ventilation function tests, arterial blood gas analysis, the 6-minute walking distance (6MWD) were performed.Self-control analysis was used to evaluate the treatment effect. Results (1)Forced expiratory volume in the first second (FEV1) changes: there was no significant difference in FEV1 between the moderate group and the group B (t=1.78, 2.47, both P>0.05). The FEV1 in the severe group, the extremely severe group, the group C and the group D increased after treatment (t=6.81, 11.15, 3.07, 7.22, all P 0.05). The PaO2 in the extremely severe group and the group D increased after treatment (t=2.98, 3.08, both P 0.05). The mMRC scores in the severe group, the extremely severe group and the group D were lower than those before treatment (t=2.74, 3.00, 5.34, all P<0.05). Conclusions External diaphragm pacing treatment can improve the pulmonary ventilation function and arterial blood gas index in patients with COPD during stabilization, reduce the patient′s disease symptoms, and improve the patient′s exercise tolerance.And patients with severe impaired lung ventilation and severe symptoms benefit more. Key words: Pulmonary disease, chronic obstructive; Chronic electrical stimulation; Pulmonary rehabilitation; Diaphragmatic muscle

Background: Adequate oxygenation to treat hypoxia by suitable oxygen delivery pattern is the essence of pediatric critical care medicine. Monitoring oxygen saturation (SpO 2 ) is thus essential in order to decide course of treatment. It is commonly carried out using painless sequential non-invasive pulse oximetry as well by severely painful random arterial blood gas (ABG) analysis. Methods: This study compared both methods to determine the impact of various oxygen delivery patterns upon SpO 2 at bedside for meaningful and continuous evaluation. In a prospective cohort adopted for study, 60 children from acute pediatric wards of an academic tertiary referral hospital were observed. Children were eligible for enrollment using cross sectional approach, if the treating pediatricians ordered an ABG, on pulse oximetry monitoring with oxygen support by any oxygen delivery device using a validated checklist. Results: Among all the samples, 60 % were infants and 55 % were male. Complaints on admission were vomiting (35%), shortness of breath (33%), diarrhea (28%), lethargy (31%) and Kussmaul breathing (30%). SpO 2 was > 90% for 88% of children. Oxy hood box was used to deliver oxygen to 73% of children. SpO 2 had positive correlation with oxygen delivery methods (r = 0.8) and partial pressure of oxygen (PaO 2 ) by ABG analysis had positive correlation with SpO 2 by pulse oximetry (r = 0.9). Conclusions: Pulse oximetry can be used as a reliable bed side tool to evaluate oxygen delivery patterns and diagnose early respiratory failure in emergency settings where ABG analysis facility is not available. Int J Clin Pediatr. 2020;9(3):72-76 doi: https://doi.org/10.14740/ijcp388

Pompe disease is an autosomal recessive disorder caused by deficiency of the acid α-glucosidase (GAA) enzyme. GAA deficiency induces progressive glycogen accumulation which leads to weakness of the respiratory muscle including the diaphragm. Pompe disease is one of the few myopathies, for which an established therapy is available. Thus, earlier detection of potential late-onset Pompe disease (LOPD) and earlier intervention would have a significant clinical impact. Our hypothesis is that sleep problems including sleep disordered breathing (SDB) and clinical symptoms may indicate an early stage of LOPD since decreased respiratory muscle activity generally first presents during sleep. Thus, the aims of this prospective, multicenter observational cohort study in Japan (PSSAP-J) are to demonstrate a higher prevalence of LOPD in a sleep lab-based population (primary outcome), and to identify predictive factors for LOPD from findings in diagnostic polysomnography (PSG) and clinical symptoms (secondary outcomes). The study design is a prospective multicenter observational cohort study. Consecutive patients who present to sleep labs due to suspected SDB for an overnight PSG will be enrolled. All patients will be measured for creatine kinase, GAA activity, and if necessary, genetic analysis of GAA. Furthermore, chest X-ray, pulmonary function test, and arterial blood gas analysis will be collected. Then, prevalence and specific findings of LOPD will be assessed. Congenital myopathy shows a shift from slow-deep to rapid-shallow breathing during transition from wakefulness to sleep accompanying a symptom of waking with gasping (actual further results are pending). The distribution in respiratory physiology between during wakefulness and sleep specific to LOPD may provide insights into early-stage detection. UMIN000039191, UMIN Clinical Trials Registry ( http://www.umin.ac.jp/ctr ).

IntroductionPerforming lung function test in geriatric patients has never been an easy task. With well-established evidence indicating impaired small airway function and air trapping in patients with geriatric COPD, utilizing forced oscillation technique (FOT) as a supplementary tool may aid in the assessment of lung function in this population.AimsTo study the use of FOT in the assessment of airflow limitation and air trapping in geriatric COPD patients.Study designA cross-sectional study in a public hospital in Hong Kong. ClinicalTrials.gov ID: NCT01553812.MethodsGeriatric patients who had spirometry-diagnosed COPD were recruited, with both FOT and plethysmography performed. “Resistance” and “reactance” FOT parameters were compared to plethysmography for the assessment of air trapping and airflow limitation.ResultsIn total, 158 COPD subjects with a mean age of 71.9±0.7 years and percentage of forced expiratory volume in 1 second of 53.4±1.7 L were recruited. FOT values had a good correlation (r=0.4–0.7) to spirometric data. In general, X values (reactance) were better than R values (resistance), showing a higher correlation with spirometric data in airflow limitation (r=0.07–0.49 vs 0.61–0.67), small airway (r=0.05–0.48 vs 0.56–0.65), and lung volume (r=0.12–0.29 vs 0.43–0.49). In addition, resonance frequency (Fres) and frequency dependence (FDep) could well identify the severe type (percentage of forced expiratory volume in 1 second <50%) of COPD with high sensitivity (0.76, 0.71) and specificity (0.72, 0.64) (area under the curve: 0.8 and 0.77, respectively). Moreover, X values could stratify different severities of air trapping, while R values could not.ConclusionFOT may act as a simple and accurate tool in the assessment of severity of airflow limitation, small and central airway function, and air trapping in patients with geriatric COPD who have difficulties performing conventional lung function test. Moreover, reactance parameters were better than resistance parameters in correlation with air trapping.

Acute Effects of Liposome Aerosol Inhalation on Pulmonary Function in Healthy Human Volunteers

Preoperative Pulmonary Consultation at a University Hospital