Staffieri Francesco, De Monte Valentina, De Marzo Carmelinda, Grasso Salvatore, Crovace Antonio
Dipartimento dell'Emergenza e dei Trapianti di Organi (DETO), Sezione di Chirurgia Veterinaria, Facoltà di Medicina Veterinaria, Università degli Studi di Bari, Valenzano (Bari), Italy.
Vet Anaesth Analg. 2010 Nov;37(6):483-90. doi: 10.1111/j.1467-2995.2010.00567.x.
To compare the effects of two fractions of inspired oxygen (FiO(2)) (0.4 and 1) on lung aeration and gas exchange during general anaesthesia in cats.
Randomized, blinded, controlled study.
Thirty healthy, mixed breed, client owned female cats.
Cats were premedicated intramuscularly with acepromazine (0.03 mg kg(-1)) and medetomidine (0.015 mg kg(-1)). Anaesthesia was induced with propofol (5 mg kg(-1)) and, after orotracheal intubation, maintained with isoflurane carried by either 100% oxygen (G100, n=15) or an oxygen-air mixture with 40% oxygen (G40, n=15). All cats were placed in dorsal recumbency and breathed spontaneously throughout the entire procedure. Following surgery (ovariectomy), a spiral computed tomography (CT) of the thorax was performed, arterial oxygen (PaO(2)) and carbon dioxide (PaCO(2)) tensions were measured and alveolar-arterial gradient of oxygen [P(A-a)O(2) ] calculated. The CT images were analysed for lung aeration by the analysis of radiograph attenuations (Hounsfield units, HU), according to the following classification: hyperinflated area (-1000 to -900 HU), normally aerated area (-900 to -500 HU), poorly aerated area (-500 to -100 HU) and non-aerated area (-100 to +100 HU). The groups were compared using one-way anova.
Compared to G100, the normally-aerated lung area was significantly greater and the poorly-aerated and non-aerated areas were significantly smaller in G40. PaCO(2) was similar in both groups. PaO(2) and P(A-a)O(2) were significantly higher in G100. In both groups, pulmonary atelectasis developed preferentially in the caudal lung fields.
In cats anaesthetised with isoflurane, the administration of an FiO(2) of >0.9 significantly impaired lung aeration and gas exchange as compared to an FiO(2) of 0.4.
An FiO(2) of 0.4 may better preserve lung aeration and gas exchange in anaesthetised spontaneously breathing cats but monitoring is essential to ensure oxygenation is adequate.
比较两种吸入氧分数（FiO₂）（0.4和1）对猫全身麻醉期间肺通气和气体交换的影响。
随机、盲法、对照研究。
30只健康的、混种的、客户拥有的雌性猫。
猫肌肉注射乙酰丙嗪（0.03 mg kg⁻¹）和美托咪定（0.015 mg kg⁻¹）进行术前用药。用丙泊酚（5 mg kg⁻¹）诱导麻醉，经口气管插管后，用100%氧气（G100，n = 15）或含40%氧气的氧气 - 空气混合物（G40，n = 15）携带异氟烷维持麻醉。所有猫在整个过程中均取仰卧位并自主呼吸。手术后（卵巢切除术），进行胸部螺旋计算机断层扫描（CT），测量动脉血氧（PaO₂）和二氧化碳（PaCO₂）分压，并计算肺泡 - 动脉氧梯度[P(A - a)O₂]。根据以下分类通过分析射线衰减（亨氏单位，HU）对CT图像进行肺通气分析：过度充气区域（-1000至-900 HU）、正常通气区域（-900至-500 HU）、通气不良区域（-500至-100 HU）和无通气区域（-100至+100 HU）。使用单因素方差分析对组间进行比较。
与G100相比，G40中正常通气的肺区域明显更大，通气不良和无通气区域明显更小。两组的PaCO₂相似。G100中的PaO₂和P(A - a)O₂明显更高。在两组中，肺不张均优先发生在肺尾叶区域。
在异氟烷麻醉的猫中，与FiO₂为0.4相比，给予FiO₂>0.9会显著损害肺通气和气体交换。
FiO₂为0.4可能更好地维持麻醉状态下自主呼吸猫的肺通气和气体交换，但监测对于确保充分氧合至关重要。
