Department of Child Health, School of Clinical Sciences, St Michael's Hospital, Level D, University of Bristol, Southwell Street, BS2 8EG Bristol, UK.
Intensive Care Med. 2012 Feb;38(2):316-23. doi: 10.1007/s00134-011-2442-7. Epub 2011 Dec 13.
To assess the effect of 18 hour (h) 50% xenon (Xe) inhalation at normothermia (NT, 38.5°C) or hypothermia (HT, 33.5°C) on mean arterial blood pressure (MABP), inotropic support and heart rate (HR) following an induced perinatal global hypoxic-ischaemic insult (HI) in newborn pigs.
Newborn pigs ventilated under inhalational anaesthesia, following a 45 min HI (inhaled oxygen fraction reduced until amplitude integrated electroencephalogram was less than 7 μV), were randomised to three Xe (n = 45) (50% Xe 18 h with NT, HT 12 h or HT 24 h) or three non-Xe groups (n = 53) (0% Xe with NT, HT 12 h or HT 24 h) under otherwise identical conditions. We measured MABP and HR every minute. Hypotension (MABP <40 mmHg) was treated sequentially with 2 × 10 mL/kg saline, dopamine, norepinephrine and hydrocortisone if required.
Xe maintained higher MABP during HT (5.1 mmHg, 95% CI 2.34, 7.89), rewarming (10.1 mmHg, 95% CI 6.26, 13.95) and after cessation (4.1 mmHg, 95% CI 0.37, 7.84) independent of HT, inotropic support and acidosis. Xe reduced the duration of inotropic support by 12.6 h (95% CI 5.5, 19.73). Inotropic support decreased the HR reduction induced by HT from 9 to 5 bpm/°C during cooling and from 10-7 to 4-3 bpm/°C during rewarming. There was no interaction between Xe, HT, inotropic support and acidosis. Xe during HT cleared lactate faster; 3 h post-HI median (IQR) values of (Xe HT) 2.8 mmol/L (0.9, 3.1) vs. (HT) 5.9 mmol/L (2.5, 7.9), p = 0.0004.
Xe maintained stable blood pressure, thereby reducing the inotropic support requirements during and after administration independently of induced HT-current neonatal encephalopathy treatment. Xe may offer haemodynamic benefits in clinical neuroprotection studies.
评估在体温正常（NT，38.5°C）或低温（HT，33.5°C）下吸入 18 小时 50%氙气对新生猪围产期全脑缺氧缺血（HI）后平均动脉血压（MABP）、正性肌力支持和心率（HR）的影响。
在吸入性麻醉下接受通气的新生猪在经历 45 分钟 HI（吸入氧气分数降低，直到振幅整合脑电图小于 7μV）后，随机分为三组氙气（n=45）（50%氙气 18 小时，NT、HT 12 小时或 HT 24 小时）或三组非氙气组（n=53）（NT 时 0%氙气、HT 12 小时或 HT 24 小时），在其他条件相同的情况下。我们每一分钟测量一次 MABP 和 HR。低血压（MABP<40mmHg）用 2×10mL/kg 生理盐水、多巴胺、去甲肾上腺素和氢化可的松序贯治疗，如果需要的话。
氙气在 HT 期间（5.1mmHg，95%CI 2.34，7.89）、复温期间（10.1mmHg，95%CI 6.26，13.95）和停止后（4.1mmHg，95%CI 0.37，7.84）维持更高的 MABP，与 HT、正性肌力支持和酸中毒无关。氙气减少了 12.6 小时的正性肌力支持时间（95%CI 5.5，19.73）。HT 期间的正性肌力支持降低了 HT 诱导的 HR 降低，从冷却期间的 9 至 5 bpm/°C，从复温期间的 10-7 至 4-3 bpm/°C。氙气、HT、正性肌力支持和酸中毒之间没有相互作用。HT 期间的氙气更快地清除乳酸，HI 后 3 小时中位数（IQR）值为（Xe HT）2.8mmol/L（0.9，3.1）与（HT）5.9mmol/L（2.5，7.9），p=0.0004。
氙气维持稳定的血压，从而减少了与诱导 HT 相关的治疗期间和治疗后的正性肌力支持需求，目前氙气是治疗新生儿脑病的方法。氙气可能在临床神经保护研究中提供血流动力学益处。
