Determination of the minimum alveolar concentration (MAC) and cardiopulmonary effects of sevoflurane in sheep
| Autor: | Giovanni Sotgiu, Bernd Driessen, Valentino Melosu, Lauren R. Duffee, Antonio Mario Scanu, N. Columbano |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Methyl Ethers
Minimum alveolar concentration 040301 veterinary sciences Bicarbonate Hemodynamics Sevoflurane 0403 veterinary science 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine 030202 anesthesiology Interquartile range medicine Animals Respiratory system Sheep General Veterinary Dose-Response Relationship Drug business.industry Respiration 04 agricultural and veterinary sciences Pulmonary Alveoli chemistry Anesthesia Anesthetics Inhalation Arterial blood Female Blood Gas Analysis business Anesthesia Inhalation Respiratory minute volume medicine.drug |
| Zdroj: | Veterinary anaesthesia and analgesia. 45(4) |
| ISSN: | 1467-2995 |
| Popis: | Objective To determine sevoflurane’s minimum alveolar concentration (MACSEVO) and its cardiopulmonary effects in sheep. Study design Prospective experimental study. Animals A group of 10 female nonpregnant Sardinian milk sheep. Methods Anesthesia was induced in each sheep twice with sevoflurane in oxygen. After a 30 minute equilibration at end-tidal sevoflurane concentration (F e ʹSevo) of 2.8%, an electrical stimulus (5 Hz/1 ms/50 mA) was applied to the right thoracic limb for 1 minute or until gross purposeful movement occurred. The F e ʹSevo was then changed using a 0.2% up-and-down protocol, dependent on whether or not the response was positive, and then noxious stimulation was repeated. The MACSEVO was defined as the mean F e ʹSevo between that allowing purposeful movement and that not. The group of 10 sheep were re-anesthetized and MACSEVO was re-determined. Thereafter, F e ʹSevo was maintained for 15 minutes each at concentrations corresponding to 1.0, 1.3, 1.6, 1.9 and 0.75 MACSEVO multiples, and cardiopulmonary, blood gas, acid-base variables and plasma electrolytes were determined. Also, time to induction of anesthesia, extubation and recovery were recorded. Results The mean ± standard deviation of the MACSEVO was 2.74 ± 0.38%. Median (interquartile range) time to intubation was 3.13 (2.98–3.33) minutes, time to extubation was 6.85 ± 2.65 minutes and time to recovery was 13.4 ± 5.2 minutes. With increasing F e ʹSevo, arterial blood pressures progressively decreased as did minute ventilation, which in turn caused end-tidal carbon dioxide, arterial partial pressure of carbon dioxide and bicarbonate values to steadily increase without significantly affecting arterial partial pressure of oxygen. Conclusions and clinical relevance The reported MACSEVO agrees with published data in this and other species. Administration of sevoflurane in sheep caused marked hemodynamic and respiratory depression, but soon after turning off the vaporizer, sheep could be extubated and recovered rapidly and event-free. |
| Databáze: | OpenAIRE |
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