Iohexol gastrointestinal transit times in cockatiels under sedation with intranasal midazolam by computed radiography

ABSTRACT: This study used contrast radiography to evaluate gastrointestinal transit times in cockatiels (Nymphicus hollandicus) and investigated the sedative effects of intranasal midazolam in this species and its usefulness in facilitating the manual restraint required for radiographic studies. Twelve healthy adult cockatiels received intranasal midazolam at dose of 2 mg/kg, and iohexol at 15 ml/kg by crop gavage. Radiographic images were obtained before contrast administration, 3 minutes after and then each 10 minutes for 90 minutes. Sedation quality of the bird was evaluated during the radiographic study and assessed according to an adapted visual sedation scale. Three minutes after iohexol administration, the cervical oesophagus and the crop were filled in all birds. At the same time, the contrast medium reached the thoracic oesophagus, proventriculus, isthmus and ventriculus in most birds. In all cockatiels, median (range) transit times were 3 (3-10) minutes for proventriculus and ventriculus, 10 (10-40) minutes for small intestine and 45 (30-70) minutes for large intestine. The overall gastrointestinal transit time was 50 (30-90) minutes.Crop remained filled with iohexol throughout the study, while oesophagus and isthmus presented a pattern of contrast progression different from the other gastrointestinal segments. According to the visual sedation scale, cockatiels presented a moderate to intense muscular relaxation, and intranasal midazolam seems to be an appropriate sedation protocol for radiographic study. All cockatiels remained healthy after the study and presented clear and watery stools at least 12 hours after, due to gastrointestinal emptying.

摘要：本研究采用放射造影成像技术，评估鸡尾鹦鹉（Nymphicus hollandicus）的胃肠道转运时间，并探讨鼻内咪达唑仑对该物种的镇静效果，及其在辅助完成放射成像研究所需人工保定中的应用价值。本研究纳入12只健康成年鸡尾鹦鹉，给予剂量为2 mg/kg的鼻内咪达唑仑，并经嗉囊插管灌服15 ml/kg的碘海醇（iohexol）。分别于对比剂给药前、给药后3分钟，随后每10分钟采集一次放射成像图像，持续90分钟。研究期间，通过改良视觉镇静评分量表对受试鹦鹉的镇静质量进行评估。碘海醇给药后3分钟，所有受试鹦鹉的颈段食管与嗉囊均被造影剂充盈；与此同时，造影剂已抵达多数受试鹦鹉的胸段食管、腺胃（proventriculus）、胃峡部（isthmus）与肌胃（ventriculus）。所有受试鸡尾鹦鹉的胃肠道转运时间中位数（范围）为：腺胃与肌胃3（3~10）分钟，小肠10（10~40）分钟，大肠45（30~70）分钟；总胃肠道转运时间为50（30~90）分钟。整个研究期间，嗉囊始终充盈碘海醇，而食管与胃峡部的造影剂充盈模式与其他胃肠道节段存在差异。根据视觉镇静评分量表，受试鸡尾鹦鹉表现出中度至重度的肌肉松弛，鼻内咪达唑仑可作为适用于放射成像研究的镇静方案。所有受试鸡尾鹦鹉在研究结束后均保持健康，且因胃肠道排空，至少在术后12小时内排出清澈水样粪便。