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Sanchez AF, Ambrósio AM, Pinto ACBCF, Pereira MAA, Andrade FSRM, Rodrigues RR, de Carvalho Martins AR, Baroni CO, Ferrante B, Fantoni DT. Effects of a stepwise alveolar recruitment maneuver on lung volume distribution in dogs assessed by computed tomography. Front Vet Sci 2024; 10:1232635. [PMID: 38292132 PMCID: PMC10825017 DOI: 10.3389/fvets.2023.1232635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 12/19/2023] [Indexed: 02/01/2024] Open
Abstract
Background Pulmonary atelectasis is a commonly occurs during anesthesia. In these cases, mechanical ventilation (MV) associated with alveolar recruitment maneuvers (ARMs) and positive end-expiratory pressure (PEEP) is indicated to reverse the condition, ensure adequate gas exchange and improve oxygenation. ARMs can trigger volutrauma, barotrauma, and atelectrauma. Therefore, computed tomography (CT) is the gold-standard method for monitoring lung aeration after ARM. Objective To evaluate lung volume distribution after stepwise ARMs using computed tomography (CT). Methods Twelve dogs weighing 24.0 ± 6.0 kg, aged 3 ± 1 years, of both sexes and different breeds, underwent orchiectomy or ovariohysterectomy. The animals were anesthetized and ventilated in volume-controlled mode. ARMs were then initiated by positive end-expiratory pressure (PEEP) titration (5, 10, 15, and 20 cmH2O). CT scans, cardiovascular parameters, and ventilatory mechanics were evaluated at all time points. Data were assessed for normality using the Shapiro-Wilk test and a two-way analysis of variance, followed by a post-hoc Bonferroni test to identify differences between time points. Statistical significance was attributed to a value of p of <0.05. Results CT demonstrated that the ARMs increased ventilation throughout the lung, including the dependent regions, with volumes that increased and decreased proportionally with PEEP titration. When they reached PEEP 10 and 5 cmH2O descending (d), they remained significantly higher than those in PEEP 0 cmH2O (baseline). Static compliance improved about 40% at PEEP 10d and PEEP 5d compared to baseline. There was an increase in heart rate (HR) from PEEP 15 increasing (i) (74.5%) to PEEP 10d (54.8%) compared to baseline. Mean arterial blood pressure (MABP) decreased approximately 9% from PEEP 15i to PEEP 15d compared to baseline. Conclusion Lung attenuation and regional and global volumes assessed by CT showed that maximum pulmonary aeration distribution followed by PEEP titration occurred at PEEP 20 cmH2O, maintaining the lungs normoaerated and without hyperaeration.
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Affiliation(s)
- Ana Flávia Sanchez
- Department of Surgery, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, São Paulo, Brazil
| | - Aline Magalhães Ambrósio
- Department of Surgery, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, São Paulo, Brazil
| | - Ana Carolina B. C. Fonseca Pinto
- Department of Veterinary Clinical Sciences, Diagnostic Imaging Purdue University College of Veterinary Medicine, West Lafayette, IN, United States
| | - Marco Aurélio Amador Pereira
- Department of Surgery, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, São Paulo, Brazil
| | | | - Renata Ramos Rodrigues
- Department of Surgery, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, São Paulo, Brazil
| | | | - Carina Outi Baroni
- Department of Surgery, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, São Paulo, Brazil
| | - Bruno Ferrante
- Department of Surgery, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, São Paulo, Brazil
| | - Denise Tabacchi Fantoni
- Department of Surgery, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, São Paulo, Brazil
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Reimegård E, Lee HTN, Westgren F. Prevalence of lung atelectasis in sedated dogs examined with computed tomography. Acta Vet Scand 2022; 64:25. [PMID: 36076254 PMCID: PMC9461193 DOI: 10.1186/s13028-022-00643-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 08/30/2022] [Indexed: 11/20/2022] Open
Abstract
Background Computed tomography (CT) scanning of the lung is known to be a valuable tool when investigating lung pathology of the dog. During CT-scan the dog needs to be immobilized and general anesthesia has historically been considered as gold standard although being a more expensive and time-consuming alternative to sedation. Today, modern high speed multidetector CT-scanners offer new possibilities for sedation as an alternative. Both anesthesia and sedation can cause lung atelectasis, and this can be problematic when reading the CT-images since it potentially can masque or mimic lung pathology leading to misdiagnosis. The objective of this prospective analytic study was to investigate the prevalence of lung atelectasis and changes in lung attenuation over time in dogs that receive intravenous sedation and positioned in sternal recumbency. Results 20 dogs without known lung pathology underwent three consecutive CT-scans of the lung; the first scan was initiated as soon as the dog was sufficiently sedated, the second scan approximately 5 min after the first one and the last scan after the dog’s orthopaedic scan was completed. The dogs received intravenous sedation in a combination of dexmedetomidine and butorphanol and were kept positioned in a strict sternal recumbency during sedation and exam. Each lung lobe was individually examined in an axial plane and measurements of dorsal, ventral, and mean lung attenuation were made. Atelectasis or areas with poorly aerated lung tissue were not detected as all parts of the lobes were normally aerated at all three scans. A statistically significant increase in lung attenuation between the first and the second scan (P = 0.03) and between the first and the third scan (P = 0.0004) was seen in the ventral part of the lobes. Conclusions This study indicates that CT-examination of the lungs can be performed on sedated dogs that are kept in a sternal recumbency without development of atelectasis. It also suggests that there is an early correlation between time and increase in lung attenuation.
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Affiliation(s)
- Elin Reimegård
- Department of Diagnostic Imaging, Evidensia Södra Djursjukhuset, Månskärsvägen 13, Kungens Kurva, 141 75, Stockholm, Sweden.
| | - Helena T Nyman Lee
- Department of Diagnostic Imaging, Evidensia Södra Djursjukhuset, Månskärsvägen 13, Kungens Kurva, 141 75, Stockholm, Sweden.
| | - Frida Westgren
- Department of Diagnostic Imaging, Evidensia Södra Djursjukhuset, Månskärsvägen 13, Kungens Kurva, 141 75, Stockholm, Sweden.
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Machado ML, Soares JHN, Pypendop BH, Aguiar AJA, Braun C, Motta-Ribeiro GC, Jandre FC. Cardiovascular and Gas Exchange Effects of Individualized Positive End-Expiratory Pressures in Cats Anesthetized With Isoflurane. Front Vet Sci 2022; 9:865673. [PMID: 35601404 PMCID: PMC9114870 DOI: 10.3389/fvets.2022.865673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 03/18/2022] [Indexed: 11/13/2022] Open
Abstract
Objectives To compare the effects of four levels of end-expiratory pressure [zero (ZEEP) and three levels of positive end-expiratory pressure (PEEP)] on the cardiovascular system and gas exchange of cats anesthetized with isoflurane and mechanically ventilated for 3 h with a tidal volume of 10 ml/kg. Study Design Prospective, randomized, controlled trial. Animals Six healthy male neutered purpose-bred cats. Methods Anesthesia was induced with isoflurane and maintained at 1.3 minimum alveolar concentration. PEEP of maximal respiratory compliance (PEEPmaxCrs) was identified in a decremental PEEP titration, and cats were randomly ventilated for 3 h with one of the following end-expiratory pressures: ZEEP, PEEPmaxCrs minus 2 cmH2O (PEEPmaxCrs−2), PEEPmaxCrs, and PEEPmaxCrs plus 2 cmH2O (PEEPmaxCrs+2). Cardiovascular and gas exchange variables were recorded at 5, 30, 60, 120, and 180 min (T5 to T180, respectively) of ventilation and compared between and within ventilation treatments with mixed-model ANOVA followed by Dunnet's and Tukey's tests (normal distribution) or Friedman test followed by the Dunn's test (non-normal distribution). Significance to reject the null hypothesis was considered p < 0.05. Results Mean arterial pressure (MAP—mmHg) was lower in PEEPmaxCrs+2 [63 (49–69); median (range)] when compared to ZEEP [71 (67–113)] at T5 and stroke index (ml/beat/kg) was lower in PEEPmaxCrs+2 (0.70 ± 0.20; mean ± SD) than in ZEEP (0.90 ± 0.20) at T60. Cardiac index, oxygen delivery index (DO2I), systemic vascular resistance index, and shunt fraction were not significantly different between treatments. The ratio between arterial partial pressure and inspired concentration of oxygen (PaO2/FIO2) was lower in ZEEP than in the PEEP treatments at various time points. At T180, DO2I was higher when compared to T5 in PEEPmaxCrs. Dopamine was required to maintain MAP higher than 60 mmHg in one cat during PEEPmaxCrs and in three cats during PEEPmaxCrs+2. Conclusion In cats anesthetized with isoflurane and mechanically ventilated for 3 h, all levels of PEEP mildly improved gas exchange with no significant difference in DO2I when compared to ZEEP. The PEEP levels higher than PEEPmaxCrs−2 caused more cardiovascular depression, and dopamine was an effective treatment. A temporal increase in DO2I was observed in the cats ventilated with PEEPmaxCrs. The effects of these levels of PEEP on respiratory mechanics, ventilation-induced lung injury, as well as in obese and critically ill cats deserve future investigation for a better understanding of the clinical use of PEEP in this species.
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Affiliation(s)
- Marcela L. Machado
- William Pritchard Veterinary Medical Teaching Hospital, University of California, Davis, Davis, CA, United States
| | - Joao H. N. Soares
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
- *Correspondence: Joao H. N. Soares
| | - Bruno H. Pypendop
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - Antonio J. A. Aguiar
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
- Departamento de Cirurgia e Anestesiologia Veterinária, Faculdade de Medicina Veterinária e Zootecnia, UNESP—Univ. Estadual Paulista, Botucatu, Brazil
| | - Christina Braun
- Anaesthesiology and Perioperative Intensive Care, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Gabriel C. Motta-Ribeiro
- Laboratory of Pulmonary and Cardiovascular Engineering, Biomedical Engineering Program/COPPE, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Frederico C. Jandre
- Laboratory of Pulmonary and Cardiovascular Engineering, Biomedical Engineering Program/COPPE, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Biomedical Instrumentation Laboratory, Biomedical Engineering Program/COPPE, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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Hunt TD, Wallack ST. Minimal atelectasis and poorly aerated lung on thoracic CT images of normal dogs acquired under sedation. Vet Radiol Ultrasound 2021; 62:647-656. [PMID: 34672040 DOI: 10.1111/vru.13016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 05/29/2021] [Accepted: 06/01/2021] [Indexed: 11/29/2022] Open
Abstract
General anesthesia optimizes image quality of thoracic CT in dogs by providing patient immobilization and respiratory control. However, it also comes with disadvantages that may serve as a detractor to the use of CT in veterinary practice. With the use of multidetector helical CT combined with injectable sedation for restraint, parameters such as atelectasis and poorly aerated lung should not be appreciably different from what has been observed in dogs under general anesthesia. This prospective pilot study aimed to evaluate the mean lung attenuation and the amount of atelectasis and poorly aerated lung on thoracic CT images acquired under injectable sedation in normal dogs. The entire thorax of 10 client-owned dogs was scanned. Attenuation measurements were generated by three-dimensional reconstruction software. Mean ± SD lung attenuation was -707.0 ± 60.0. Atelectasis was not identified on any of the scans. Hypoinflated lung, the percentage of lung parenchyma with attenuation greater than -500 and -250 Hounsfield units (HU), was 10.7 ± 4.7% and 2.4 ± 1.2% (mean ± SD), respectively. There was no significant change in these percentages over time. Compared to previously published data, thoracic CT images obtained under sedation had mean attenuation comparable to normal expiratory lung and a lower percentage of poorly aerated lung compared to that of anesthetized dogs. Using sedation to complete canine thoracic CT does not itself lead to alterations of lung attenuation and may confer less hypoinflation and atelectasis than general anesthesia.
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Affiliation(s)
- Tania D Hunt
- Veterinary Imaging Center of San Diego, San Diego, California, USA
| | - Seth T Wallack
- Veterinary Imaging Center of San Diego, San Diego, California, USA
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Panopoulos I, Auriemma E, Specchi S, Diana A, Pietra M, Papastefanou A, Zini E, Cipone M. 64-multidetector CT anatomical assessment of the feline bronchial and pulmonary vascular structures. J Feline Med Surg 2019; 21:893-901. [PMID: 30407139 PMCID: PMC11132249 DOI: 10.1177/1098612x18807778] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES The aim of the study was to provide a detailed anatomical study of the feline bronchial and vascular structures by using CT angiography (CTA). METHODS Adult cats with no respiratory clinical signs were enrolled in a CTA protocol to provide an anatomical study of the thorax. The dimensions, number of branches and branching pattern (monopodial vs dichotomic) of both bronchial and pulmonary vascular structures were evaluated under positive inspiration apnoea. A linear generalised estimating equations analysis (Spearman's rho) was used to identify statistical correlation between tracheal diameter, age and body weight of the cats. RESULTS Fourteen cats met the inclusion criteria. The pulmonary arteries had larger diameters than the pulmonary veins, and the pulmonary veins had larger diameters than the bronchial structures. A higher number of segmental bronchial and pulmonary vascular branches was observed in the left caudal lung lobe than in the other lobes. The monopodial branching pattern of both bronchial and pulmonary vascular structures was predominant in all cats of our study (100%) in cranial, caudal and right middle lung lobes, while a dichotomic branching pattern of the bronchial and pulmonary vascular structures of the accessory lung lobe was seen in 13 cats (93%). Thirteen cats (93%) had three pulmonary vein ostia, and one cat (7%) also presented with an additional left intermediate pulmonary vein ostium. Variation in the number of segmental pulmonary vein branches was noted in the right caudal lung lobe. There was no statistical correlation between tracheal diameter, age and weight. CONCLUSIONS AND RELEVANCE Architecture of the feline bronchovascularr structures belongs to a mixed type of monopodial and dichotomic branching pattern. In cats, the pulmonary venous drainage system predominately presents three pulmonary vein ostia. Variations in the type of formation and the number of branches of the pulmonary venous drainage system were noted.
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Affiliation(s)
| | - Edoardo Auriemma
- Department of Diagnostic Imaging, Veterinary Institute of Novara, Novara, Italy
| | - Swan Specchi
- Department of Diagnostic Imaging, Veterinary Institute of Novara, Novara, Italy
| | - Alessia Diana
- Department of Veterinary Medical Sciences, University of Bologna, Italy
| | - Marco Pietra
- Department of Veterinary Medical Sciences, University of Bologna, Italy
| | | | - Eric Zini
- Clinic for Small Animal Internal Medicine, Zurich University, Vetsuisse-Faculty, Zurich, Switzerland
- Department of Animal Medicine, Production and Health, University of Padua, Legnaro, Italy
- Department of Internal Medicine, Istituto Veterinario di Novara, Novara, Italy
| | - Mario Cipone
- Department of Veterinary Medical Sciences, University of Bologna, Italy
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Darawiroj D, Choisunirachon N. Morphological assessment of cat kidneys using computed tomography. Anat Histol Embryol 2019; 48:358-365. [PMID: 31106459 DOI: 10.1111/ahe.12448] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 04/10/2019] [Accepted: 04/26/2019] [Indexed: 11/30/2022]
Abstract
There are numerous publications about feline renal imaging information; however, none have established reference values for kidney size using computed tomography (CT). This study aimed to determine renal size and shape as well as the morphology of renal-related structures in clinically normal cats (Felis catus) that underwent CT. Twenty-seven healthy cats underwent pre- and post-iodinated contrast-enhanced CT. Most cat (59%) kidneys were located at the same level. The average pre-contrast dimensions of the left kidney included a width of 2.46 ± 0.28 cm, a length of 3.52 ± 0.44 cm and a height 2.19 ± 0.31 cm, whereas those of the right kidneys were 2.45 ± 0.27 cm, 3.54 ± 0.46 cm and 2.05 ± 0.23 cm, respectively. After contrast enhancement, kidneys were slightly enlarged though not significantly. Additionally, renal length (LK or RK) was compared with second lumbar vertebra (L2) length and abdominal aorta diameter (AO). AO was significantly larger in male cats whereas L2 length appeared longer in male cats, but was not statistically different from the female cats. The LK/L2 and RK/L2 ratios were 2.29 ± 0.23 and 2.36 ± 0.20, respectively, and the LK/AO and RK/AO were 11.72 ± 1.37 and 12.05 ± 1.47, respectively. Renal vessels were examined. The renal vein was obviously larger than the renal artery, and paired renal veins were observed periodically. This study provides CT information about the feline kidney, which may help to establish reference values and information regarding renal structure prior to surgery in practice.
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Affiliation(s)
- Damri Darawiroj
- Department of Anatomy, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - Nan Choisunirachon
- Department of Surgery, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
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Foo TS, Pilton JL, Hall EJ, Martinez-Taboada F, Makara M. Effect of body position and time on quantitative computed tomographic measurements of lung volume and attenuation in healthy anesthetized cats. Am J Vet Res 2018; 79:874-883. [PMID: 30058848 DOI: 10.2460/ajvr.79.8.874] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To quantify the effect of time and recumbency on CT measurements of lung volume and attenuation in healthy cats under general anesthesia. ANIMALS 8 healthy research cats. PROCEDURES Anesthetized cats were positioned in sternal recumbency for 20 minutes and then in left, right, and left lateral recumbency (40 minutes/position). Expiratory helical CT scan of the thorax was performed at 0 and 20 minutes in sternal recumbency and at 0, 5, 10, 20, 30, and 40 minutes in each lateral recumbent position. For each lung, CT measurements of lung volume and attenuation and the extent of lung areas that were hyperaerated (-1,000 to -901 Hounsfield units [HU]), normoaerated (-900 to -501 HU), poorly aerated (-500 to -101 HU), or nonaerated (-100 to +100 HU [indicative of atelectasis]) were determined with a semiautomatic threshold-based technique. A restricted maximum likelihood analysis was performed. RESULTS In lateral recumbency, the dependent lung had significantly greater attenuation and a lower volume than the nondependent lung. Within the dependent lung, there was a significantly higher percentage of poorly aerated lung tissue, compared with that in the nondependent lung. These changes were detected immediately after positioning the cats in lateral recumbency and remained static with no further significant time-related change. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that once anesthetized healthy cats were positioned in lateral recumbency, the dependent lung lobes underwent a rapid reduction in lung volume and increase in lung attenuation that did not progress over time, predominantly attributable to an increase in poorly aerated lung tissue.
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8
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Hahn H, Specchi S, Masseau I, Reinero C, Benchekroun G, Rechy J, Seiler G, Pey P. The computed tomographic “tree-in-bud” pattern: Characterization and comparison with radiographic and clinical findings in 36 cats. Vet Radiol Ultrasound 2017; 59:32-42. [DOI: 10.1111/vru.12564] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 07/17/2017] [Indexed: 12/18/2022] Open
Affiliation(s)
- Harriet Hahn
- Department of Diagnostic Imaging, Université Paris-Est; Ecole Nationale Vétérinaire d'Alfort; Maisons-Alfort France
| | - Swan Specchi
- Department of Clinical Sciences; Veterinary Institute of Novara; Strada Provinciale 9, 28060, Granozzo con Monticello (NO) Italy
| | - Isabelle Masseau
- Department of Clinical Sciences, Faculté de Médecine Vétérinaire; Université de Montréal; Saint-Hyacinthe QC Canada
| | - Carol Reinero
- Department of Veterinary Medicine and Surgery and Comparative Internal Medicine Laboratory, College of Veterinary Medicine; University of Missouri; Columbia MO
| | - Ghita Benchekroun
- Department of Internal Medicine, Université Paris-Est; Ecole Nationale Vétérinaire d'Alfort; Maisons-Alfort France
| | - Jaime Rechy
- Department of Molecular Biomedical Sciences; North Carolina State University; Raleigh NC
| | - Gabriela Seiler
- Department of Molecular Biomedical Sciences; North Carolina State University; Raleigh NC
| | - Pascaline Pey
- Department of Diagnostic Imaging, Université Paris-Est; Ecole Nationale Vétérinaire d'Alfort; Maisons-Alfort France
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Allison A, Huizing X, Jolliffe C, Schaafsma I. Effect of fixed value positive end expiratory pressure valves on canine thoracic volume and atelectasis. J Small Anim Pract 2017; 58:645-651. [DOI: 10.1111/jsap.12710] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 05/01/2017] [Accepted: 05/23/2017] [Indexed: 11/28/2022]
Affiliation(s)
- A. Allison
- Anaesthesia Department; Animal Health Trust; Newmarket Suffolk CB8 7UU UK
| | - X. Huizing
- Diagnostic Imaging Department, Faculty of Veterinary Science; University Utrecht; Utrecht 3584 The Netherlands
| | - C. Jolliffe
- Anaesthesia Department; Animal Health Trust; Newmarket Suffolk CB8 7UU UK
| | - I. Schaafsma
- Diagnostic Imaging Department, Animal Heath Trust; Newmarket Suffolk CB8 7UU UK
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Fowler J, Stieger-Vanegas SM, Vanegas JA, Bobe G, Poulsen KP. Comparison of Thoracic Radiography and Computed Tomography in Calves with Naturally Occurring Respiratory Disease. Front Vet Sci 2017; 4:101. [PMID: 28730151 PMCID: PMC5498470 DOI: 10.3389/fvets.2017.00101] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 06/12/2017] [Indexed: 12/12/2022] Open
Abstract
Objective To evaluate the severity and extent of lung disease using thoracic computed radiography (CR) compared to contrast-enhanced multi-detector computed tomography (MDCT) of the thorax in calves with naturally occurring respiratory disease and to evaluate the feasibility and safety of performing contrast-enhanced thoracic multi-detector MDCT examinations in sedated calves. Furthermore, to evaluate if combining CR or MDCT with respiratory scoring factors will improve prediction of the chronicity of pulmonary disease in calves. Animals Thirty Jersey heifer calves ranging in age between 25 and 89 days with naturally occurring respiratory disease. Procedures All calves were evaluated via thoracic CR and contrast-enhanced MDCT. All calves were euthanized immediately following thoracic MDCT and submitted for necropsy. Imaging and histopathology results were compared with each other. Results Thoracic MDCT was superior for evaluation of pneumonia in calves due to the lack of summation in all areas of the lungs. Intravenously administered sedation provided an adequate plane of sedation for acquiring MDCT images of diagnostic quality, without the need for re-scanning. A diagnosis of pneumonia was made with equal rate on both thoracic CR and MDCT. Although mild differences in classification of lung pattern and extent of lung disease were seen when comparing an experienced and a less experienced evaluator, the overall differences were not statistically significant. The best intra- and inter-observer agreement was noted when evaluating the cranioventral aspects of the lungs in either modality. Clinical respiratory scoring is inadequate for diagnosing chronicity of pneumonia in calves with naturally occurring pneumonia. Conclusion and clinical importance Both imaging modalities allowed diagnosis of pneumonia in calves. The cranial ventral aspects of the lungs were most commonly affected. Thoracic CR and MDCT provided similar diagnostic effectiveness in diagnosing pneumonia. However, MDCT provided better assessment of subtle details, which may be otherwise obscured due to summation artifact.
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Affiliation(s)
- Jennifer Fowler
- Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States
| | - Susanne M Stieger-Vanegas
- Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States
| | - Jorge A Vanegas
- Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, United States
| | - Gerd Bobe
- Department of Animal and Rangeland Sciences, College of Agricultural Sciences, Oregon State University, Corvallis, OR, United States.,Linus Pauling Institute, Oregon State University, Corvallis, OR, United States
| | - Keith P Poulsen
- Wisconsin Veterinary Diagnostic Laboratory, Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, United States
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Lascola KM, Clark-Price SC, Joslyn SK, Mitchell MA, O'Brien RT, Hartman SK, Kline KH. Use of manual alveolar recruitment maneuvers to eliminate atelectasis artifacts identified during thoracic computed tomography of healthy neonatal foals. Am J Vet Res 2016; 77:1276-1287. [PMID: 27805443 DOI: 10.2460/ajvr.77.11.1276] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate use of single manual alveolar recruitment maneuvers (ARMs) to eliminate atelectasis during CT of anesthetized foals. ANIMALS 6 neonatal Standardbred foals. PROCEDURES Thoracic CT was performed on spontaneously breathing anesthetized foals positioned in sternal (n = 3) or dorsal (3) recumbency when foals were 24 to 36 hours old (time 1), 4 days old (time 2), 7 days old (time 3), and 10 days old (time 4). The CT images were collected without ARMs (all times) and during ARMs with an internal airway pressure of 10, 20, and 30 cm H2O (times 2 and 3). Quantitative analysis of CT images measured whole lung and regional changes in attenuation or volume with ARMs. RESULTS Increased attenuation and an alveolar pattern were most prominent in the dependent portion of the lungs. Subjectively, ARMs did not eliminate atelectasis; however, they did incrementally reduce attenuation, particularly in the nondependent portion of the lungs. Quantitative differences in lung attenuation attributable to position of foal were not identified. Lung attenuation decreased significantly (times 2 and 3) and lung volume increased significantly (times 2 and 3) after ARMs. Changes in attenuation and volume were most pronounced in the nondependent portion of the lungs and at ARMs of 20 and 30 cm H2O. CONCLUSIONS AND CLINICAL RELEVANCE Manual ARMs did not eliminate atelectasis but reduced attenuation in nondependent portions of the lungs. Positioning of foals in dorsal recumbency for CT may be appropriate when pathological changes in the ventral portion of the lungs are suspected.
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12
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Lamb CR, Jones ID. Associations between respiratory signs and abnormalities reported in thoracic CT scans of cats. J Small Anim Pract 2016; 57:561-567. [DOI: 10.1111/jsap.12530] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 03/15/2016] [Accepted: 05/13/2016] [Indexed: 01/12/2023]
Affiliation(s)
- C. R. Lamb
- Department of Clinical Science and Service; The Royal Veterinary College; Hawkshead Lane North Mymms Hertfordshire AL9 7TA
| | - I. D. Jones
- Department of Clinical Science and Service; The Royal Veterinary College; Hawkshead Lane North Mymms Hertfordshire AL9 7TA
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13
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Diagnostic Imaging of the Lower Respiratory Tract in Neonatal Foals. Vet Clin North Am Equine Pract 2015; 31:497-514. [DOI: 10.1016/j.cveq.2015.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Masseau I, Banuelos A, Dodam J, Cohn LA, Reinero C. COMPARISON OF LUNG ATTENUATION AND HETEROGENEITY BETWEEN CATS WITH EXPERIMENTALLY INDUCED ALLERGIC ASTHMA, NATURALLY OCCURRING ASTHMA AND NORMAL CATS. Vet Radiol Ultrasound 2015; 56:595-601. [PMID: 26095161 DOI: 10.1111/vru.12267] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 04/23/2015] [Indexed: 01/16/2023] Open
Abstract
Airway remodeling is a prominent feature of feline allergic asthma but requires biopsy for characterization. Computed tomography (CT) has appeal as a minimally invasive diagnostic test. The purpose of this prospective case-control study was to compare indices of airway remodeling between cats with experimentally induced, spontaneous asthma and healthy unaffected cats using CT. We hypothesized that experimental and spontaneous feline asthma would have similar CT airway remodeling characteristics and that these would be significantly different in healthy cats. Experimentally induced asthmatic research cats (n = 5), spontaneously asthmatic pet cats (n = 6), and healthy research cats (n = 5) were scanned unrestrained using a 64-detector row CT scanner. Inspiratory breath-hold CT scans were also performed in experimentally induced asthmatic and healthy cats. Mean ± extent variation of lung attenuation for each cat was determined using an airway inspector software program and CT images were scored for lung heterogeneity by a board-certified veterinary radiologist who was unaware of cat group status. Groups were compared using one-way ANOVA (unrestrained scans) and the Student's t-test (anesthetized scans) with significance defined as P < 0.10. Experimentally asthmatic and spontaneously asthmatic cats had significantly (P = 0.028 and P = 0.073, respectively) increased lung attenuation compared to healthy cats. Heterogeneity scores were higher in experimentally induced asthmatic cat than in healthy cats. Objective quantification of lung heterogeneity and lung volume did not differ among the three groups (P = 0.311, P = 0.181, respectively). Findings supported our hypothesis. Inspiratory breath-hold anesthetized CT scans facilitated discrimination between asthmatic and healthy cats in comparison to unrestrained CT scans.
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Affiliation(s)
- Isabelle Masseau
- Department of Veterinary Medicine and Surgery, Comparative Internal Medicine Laboratory, College of Veterinary Medicine, University of Missouri, Columbia, MO
| | - Alina Banuelos
- Department of Veterinary Medicine and Surgery, Comparative Internal Medicine Laboratory, College of Veterinary Medicine, University of Missouri, Columbia, MO
| | - John Dodam
- Department of Veterinary Medicine and Surgery, Comparative Internal Medicine Laboratory, College of Veterinary Medicine, University of Missouri, Columbia, MO
| | - Leah A Cohn
- Department of Veterinary Medicine and Surgery, Comparative Internal Medicine Laboratory, College of Veterinary Medicine, University of Missouri, Columbia, MO
| | - Carol Reinero
- Department of Veterinary Medicine and Surgery, Comparative Internal Medicine Laboratory, College of Veterinary Medicine, University of Missouri, Columbia, MO
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Schliewert EC, Lascola KM, O'Brien RT, Clark-Price SC, Wilkins PA, Foreman JH, Mitchell MA, Hartman SK, Kline KH. Comparison of radiographic and computed tomographic images of the lungs in healthy neonatal foals. Am J Vet Res 2015; 76:42-52. [PMID: 25535660 DOI: 10.2460/ajvr.76.1.42] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare CT and radiographic images of the lungs in sedated healthy foals positioned in sternal recumbency and to investigate whether a relationship exists between CT-derived measurements of lung attenuation and Paco2 and Pao2. ANIMALS 6 healthy Standardbred foals < 14 days of age. PROCEDURES Thoracic CT images were acquired followed by radiographic views with each foal sedated and positioned in sternal recumbency. For each foal, both CT and radiographic images were evaluated for severity and extent of changes by lung regions on the basis of a subjective scoring system by 3 investigators. Quantitative analysis of CT images was also performed. Assessments of Pao2 and Paco2 were performed before sedation, following sedation prior to CT, and after CT prior to radiography. RESULTS Interobserver agreement for CT and radiographic image scoring was strong (0.73) and fair (0.65), respectively; intraobserver agreement was near perfect for CT (0.97) and radiographic (0.94) image scoring. Increased CT attenuation and radiographic changes were identified for all foals and were preferentially distributed in the caudoventral portion of the lungs. Radiographic scores were significantly lower than CT image scores. A positive correlation (r = 0.872) between lung attenuation and CT image score was identified. A significant increase in Paco2 was not considered clinically relevant. Significant changes in Pao2 were not observed. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that interpretation of CT images may be less subjective, compared with interpretation of radiographic images. These findings may aid in the evaluation of CT and radiographic images of neonatal foals with respiratory tract disease.
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Affiliation(s)
- Eva-Christina Schliewert
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana, IL 61802
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Lascola KM, O'Brien RT, Wilkins PA, Clark-Price SC, Hartman SK, Mitchell MA. Qualitative and quantitative interpretation of computed tomography of the lungs in healthy neonatal foals. Am J Vet Res 2014; 74:1239-46. [PMID: 23977897 DOI: 10.2460/ajvr.74.9.1239] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To qualitatively describe lung CT images obtained from sedated healthy equine neonates (≤ 14 days of age), use quantitative analysis of CT images to characterize attenuation and distribution of gas and tissue volumes within the lungs, and identify differences between lung characteristics of foals ≤ 7 days of age and foals > 7 days of age. ANIMALS 10 Standardbred foals between 2.5 and 13 days of age. PROCEDURES Foals were sedated with butorphanol, midazolam, and propofol and positioned in sternal recumbency for thoracic CT. Image analysis software was used to exclude lung from nonlung structures. Lung attenuation was measured in Hounsfield units (HU) for analysis of whole lung and regional changes in attenuation and lung gas and tissue components. Degree of lung attenuation was classified as follows: hyperinflated or emphysema, -1,000 to -901 HU; well aerated, -900 to -501 HU; poorly aerated, -500 to -101 HU; and nonaerated, > -100 HU. RESULTS Qualitative evidence of an increase in lung attenuation and patchy alveolar patterns in the ventral lung region were more pronounced in foals ≤ 7 days of age than in older foals. Quantitative analysis revealed that mean ± SD lung attenuation was greater in foals ≤ 7 days of age (-442 ± 28 HU) than in foals > 7 days of age (-521 ± 24 HU). Lung aeration and gas volumes were lower than in other regions ventrally and in the mid lung region caudal to the heart. CONCLUSIONS AND CLINICAL RELEVANCE-Identified radiographic patterns and changes in attenuation were most consistent with atelectasis and appeared more severe in foals ≤ 7 days of age than in older neonatal foals. Recognition of these changes may have implications for accurate CT interpretation in sedated neonatal foals with pulmonary disease.
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Affiliation(s)
- Kara M Lascola
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana, IL 61802, USA
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