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- Auckburally, Adam, et al.
(author)
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Effects of ventilation mode and blood flow on arterial oxygenation during pulse-delivered inhaled nitric oxide in anesthetized horses
- 2019
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In: American Journal of Veterinary Research. - : American Veterinary Medical Association (AVMA). - 0002-9645. ; 80, s. 275-283
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Journal article (peer-reviewed)abstract
- OBJECTIVETo determine the impact of mechanical ventilation (MV) and perfusion conditions on the efficacy of pulse-delivered inhaled nitric oxide (PiNO) in anesthetized horses.ANIMALS27 healthy adult horses.PROCEDURESAnesthetized horses were allocated into 4 groups: spontaneous breathing (SB) with low (< 70 mm Hg) mean arterial blood pressure (MAP; group SB-L; n = 7), SB with physiologically normal (>= 70 mm Hg) MAP (group SB-N; 8), MV with low MAP (group MV-L; 6), and MV with physiologically normal MAP (group MV-N; 6). Dobutamine was used to maintain MAP > 70 mm Hg. Data were collected after a 60-minute equilibration period and at 15 and 30 minutes during PiNO administration. Variables included Pao(2), arterial oxygen saturation and content, oxygen delivery, and physiologic dead space-to-tidal volume ratio. Data were analyzed with Shapiro-Wilk, Mann-Whitney U, and Friedman ANOVA tests.RESULTSPao(2), arterial oxygen saturation, arterial oxygen content, and oxygen delivery increased significantly with PiNO in the SB-L, SB-N, and MV-N groups; were significantly lower in group MV-L than in group MV-N; and were lower in MV-N than in both SB groups during PiNO. Physiologic dead space-to-tidal volume ratio was highest in the MV-L group.CONCLUSIONS AND CLINICAL RELEVANCEPulmonary perfusion impacted PiNO efficacy during MV but not during SB. Use of PiNO failed to increase oxygenation in the MV-L group, likely because of profound ventilation-perfusion mismatching. During SB, PiNO improved oxygenation irrespective of the magnitude of blood flow, but hypoventilation and hypercarbia persisted. Use of PiNO was most effective in horses with adequate perfusion.
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2. |
- Auckburally, Adam, et al.
(author)
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Review of hypoxaemia in anaesthetized horses: predisposing factors, consequences and management
- 2017
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In: Veterinary Anaesthesia and Analgesia. - : Elsevier BV. - 1467-2987 .- 1467-2995. ; 44, s. 397-408
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Research review (peer-reviewed)abstract
- Objective To discuss how hypoxaemia might be harmful and why horses are particularly predisposed to developing it, to review the strategies that are used to manage hypoxaemia in anaesthetized horses, and to describe how successful these strategies are and the adverse effects associated with them.Databases used Google Scholar and PubMed, using the search terms horse, pony, exercise, anaesthesia, hypoxaemia, oxygen, mortality, morbidity and ventilation perfusion mismatch.Conclusions Although there is no evidence that hypoxaemia is associated with increased morbidity and mortality in anaesthetized horses, most anaesthetists would agree that it is important to recognise and prevent or treat it. Favourable anatomical and physiological adaptations of a horse for exercise adversely affect gas exchange once the animal is recumbent. Hypoxaemia is recognised more frequently in horses than in other domestic species during general anaesthesia, although its incidence in healthy horses remains unreported. Management of hypoxaemia in anaesthetized horses is challenging and often unsuccessful. Positive pressure ventilation strategies to address alveolar atelectasis in humans have been modified for implementation in recumbent anaesthetized horses, but are often accompanied by unpredictable and unacceptable cardiopulmonary adverse effects, and some strategies are difficult or impossible to achieve in adult horses. Furthermore, anticipated beneficial effects of these techniques are inconsistent. Increasing the inspired fraction of oxygen during anaesthesia is often unsuccessful since much of the impairment in gas exchange is a direct result of shunt. Alternative approaches to the problem involve manipulation of pulmonary blood away from atelectatic regions of the lung to better ventilated areas. However, further work is essential, with particular focus on survival associated with general anaesthesia in horses, before any technique can be accepted into widespread clinical use.
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3. |
- Fahlman, Åsa, et al.
(author)
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Pulmonary gas exchange and acid-base status during immobilisation of black rhinoceroses (Diceros bicornis) in Zimbabwe
- 2016
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In: Journal of the South African Veterinary Association / Tydkrif van die Suid-Afrikaanse Veterinere. - : Medpharm Publications. - 1019-9128. ; 87
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Journal article (peer-reviewed)abstract
- When immobilising wildlife, adverse side effects can include hypoxaemia, acidosis and hypertension. Pulmonary gas exchange and acid-base status were evaluated during immobilisation of 25 free-ranging and one boma-held black rhinoceros (Diceros bicornis) in Zimbabwe. The effect of different body positions on arterial oxygenation was evaluated. A combination of the following drugs was used: an opioid (etorphine or thiafentanil), azaperone and an alpha(2)-adrenoceptor agonist (detomidine or xylazine). Respiratory and heart rates, rectal temperature and pulse oximetry-derived haemoglobin oxygen saturation were recorded. Serial arterial blood samples were analysed immediately in the field. Marked hypoxaemia and hypercapnia were recorded in immobilised free-ranging black rhinoceroses. Arterial oxygenation was higher during sternal compared to lateral recumbency. Most rhinoceroses developed acidaemia of respiratory and metabolic origin. Initially high lactate concentrations in free-ranging rhinoceroses decreased during immobilisation. Pulse oximetry was unreliable in the detection of hypoxaemia. Positioning in sternal recumbency and routine use of oxygen supplementation are recommended in the management of immobilised rhinoceroses as measures to improve arterial oxygenation.
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4. |
- Nyman, Görel, et al.
(author)
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Case Studies in Physiology : Ventilation and perfusion in a giraffe-does size matter?
- 2016
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In: Journal of applied physiology. - : American Physiological Society. - 8750-7587 .- 1522-1601. ; 121:6, s. 1374-1378
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Journal article (peer-reviewed)abstract
- The trachea in the giraffe is long but narrow, and dead space ventilation is considered to be of approximately the same size as in other mammals. Less is known about the matching between ventilation and lung blood flow. The lungs in the giraffe are large, up to 1 m high and 0.7 m wide, and this may cause considerable ventilation/perfusion (V-A/Q) mismatch due to the influence of gravitational forces, which could lead to hypoxemia. We studied a young giraffe under anesthesia using the multiple inert gas elimination technique to analyze the V-A/Q distribution and arterial oxygenation and compared the results with those obtained in other species of different sizes, including humans. V-A/Q distribution was broad but unimodal, and the shunt of blood flow through nonventilated lung regions was essentially absent, suggesting no lung collapse. The V-A/Q match was as good as in the similarly sized horse and was even comparable to that in smaller sized animals, including rabbit and rat. The match was also similar to that in anesthetized humans. Arterial oxygenation was essentially similar in all studied species. The findings suggest that the efficiency of V-A/Q matching is independent of lung size in the studied mammals that vary in weight from less than 1 to more than 400 kg.
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5. |
- Rydén, Anneli, et al.
(author)
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Cardiovascular side-effects and insulin secretion after intravenous administration of radiolabeled Exendin-4 in pigs
- 2016
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In: Nuclear Medicine and Biology. - : Elsevier BV. - 0969-8051 .- 1872-9614. ; 43:7, s. 397-402
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Journal article (peer-reviewed)abstract
- Introduction: Radiolabeled Exendin-4, a synthetic glucagon-like peptide-1 (GLP-1) analog, is used as a tracer for diagnostic purposes of beta-cells and in experimental animal research. Exendin-4 can be radiolabeled with Ga-68, I-111 n or (99)mTc and used for positron emission tomography (PET) and single-photon emission computed tomography (SPECT) imaging to diagnose insulinomas, visualization of pancreatic beta-cell mass and transplanted Islets of Langerhans. In humans, Exendin-4 is widely used as a therapeutic agent for treatment of type 2 diabetes (T2D). The compound, which is administered subcutaneously (SC) may cause nausea, vomiting and a minor increase in the heart rate (HR). However, possible side-effects on cardiovascular functions after intravenous (IV) administration have not been reported. This study describes the Exendin-4 dose at which cardiovascular side-effects occur in pigs and cynomolgus monkeys. The IV effect of the tracer on insulin secretion is also investigated in pigs. Methods: Seven clinically healthy littermate pigs (40 days old) were used; three of them were made diabetic by streptozotocin (STZ). All pigs underwent PET imaging under general anesthesia to examine the glucagon-like peptide-1 receptor (GLP-1R) in beta-cells with radiolabeled Exendin-4. A baseline tracer dose IV [Ga-68]Exendin-4 (0.025 +/- 0.010 mu g/kg) followed by a competition dose IV [Ga-68]Exendin-4 (3.98 +/- 133 mu g/kg) 60 min later were administered. Blood samples were taken and analyzed for insulin secretion by using ELISA. Cardiovascular and respiratory variables were monitored throughout the experiment. Results: Immediately after administration of the high dose [Ga-68]Exendin-4 the HR rose from 122 14 to 227 +/- 40 bpm (p < 0.01) and from 100 +/- 5 to 181 +/- 13 bpm (p < 0.01) in healthy non -diabetic and diabetes-induced pigs, respectively. The tachycardia was observed for >2 h and one healthy non-diabetic pig suffered cardiac arrest 3 h after the IV [Ga-68]Exendin-4. Arrhythmia was detected by listening to the heart with a stethoscope up to 4 days after the [Ga-68]Exendin-4 injection. In all animals, no effect on the cardiovascular system was registered after the low dose of IV [Ga-68]Exendin-4. Insulin secretion increased (p < 0.05) when IV [Ga-68]Exendin-4 was given in dosages >= 0.14 mu g/kg. Conclusions: Intravenous administration of mu g/kg [Ga-68]Exendin-4 resulted in severe tachycardia and arrhythmias in healthy non -diabetic and diabetes-induced pigs, and the insulin secretion was stimulated in healthy non diabetic animals when >= 0.14 mu g/kg [Ga-68]Exendin-4 was given.
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6. |
- Stadig, Sarah, et al.
(author)
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Evaluation and comparison of pain questionnaires for clinical screening of osteoarthritis in cats
- 2019
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In: Veterinary Record. - : Wiley. - 0042-4900 .- 2042-7670. ; 185
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Journal article (peer-reviewed)abstract
- Background Feline osteoarthritis (OA) is a common cause of long-standing pain and physical dysfunction. Performing a physical examination of a cat is often challenging. There is a need for disease-specific questionnaires or the so-called clinical metrology instruments (CMIs) to facilitate diagnosis and evaluation of treatment of feline OA. The CMI provides the owners an assessment of the cat's behavioural and lifestyle changes in the home environment. The purpose of the study was to evaluate readability, internal consistency, reliability and discriminatory ability of four CMIs.Methods This is a prospective, cross-sectional study with 142 client-owned cats. Feline OA was diagnosed based on medical history, orthopaedic examination and radiography.Results The results indicate that all four instruments have sound readability, internal consistency, are reliable over time and have good discriminatory ability. Preliminary cut-off values with optimal sensitivity and specificity were suggested for each instrument. The osteoarthritic cats showed significant changes in behavioural response to pain during orthopaedic examination, compared with sound cats.Conclusion The results indicate that all four questionnaires make an important contribution in a clinical setting, and that the cat's behavioural response to pain during physical examination should be a parameter to take into account as a possible indication of chronic pain.
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7. |
- Wiklund, Maja, et al.
(author)
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Pulsed inhaled nitric oxide improves arterial oxygenation in colic horses undergoing abdominal surgery
- 2017
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In: Veterinary Anaesthesia and Analgesia. - : Elsevier BV. - 1467-2987 .- 1467-2995. ; 44, s. 1139-1148
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Journal article (peer-reviewed)abstract
- Objective To evaluate the effect of pulsed inhaled nitric oxide (INO) on arterial oxygenation in horses during abdominal surgery.Study design Prospective, randomized, clinical trial.Animals Thirty horses that underwent abdominal surgery at the University Animal Hospital in Uppsala, Sweden.Methods Anaesthesia was induced according to a standard protocol - romifidine, butorphanol, diazepam and ketamine and maintained with isoflurane in oxygen. Fifteen horses were administered pulsed INO and 15 served as controls. After baseline data collection, pulsed INO delivery commenced. Arterial and venous blood were collected and analysed. Cardiorespiratory parameters were measured, and oxygen content and F-shunt were calculated.Results Arterial oxygen tension (PaO2) and arterial oxygen saturation (SaO(2)) increased from 10.9 +/- 5.7 kPa (82 +/- 43 mmHg) and 93 +/- 6% to 17.3 +/- 6.9 kPa (134 +/- 52 mmHg) (p < 0.0001) and 98 +/- 2% (p < 0.0001), respectively, in horses administered pulsed INO. In the control group, PaO2 and SaO(2) decreased from 13.9 +/- 9.1 kPa (104 +/- 68 mmHg) and 93 +/- 7% to 12.1 +/- 8.6 kPa (91 +/- 65 mmHg) (p = 0.0413) and 91 +/- 8% (p = 0.0256), respectively. At the end of anaesthesia, the oxygen content was significantly higher in horses administered pulsed INO compared to controls (p = 0.0126). The calculated F-shunt decreased from 39 +/- 10% to 27 +/- 6% (p < 0.0001) in horses administered pulsed INO, and remained unchanged in controls, 40 +/- 12% to 44 +/- 12%. Blood lactate concentration decreased (-17 +/- 21%) in horses administered pulsed INO (p = 0.0119), whereas no difference was measured in controls (2 +/- 31%).Conclusions and clinical relevance The present study showed that it is possible to effectively reduce the F-shunt and improve arterial oxygenation in horses during abdominal surgery by continuous delivery of pulsed INO.
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