Hopster Klaus, Kästner Sabine B R, Rohn Karl, Ohnesorge Berhard
Clinic for Horses, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany.
Vet Anaesth Analg. 2011 May;38(3):169-77. doi: 10.1111/j.1467-2995.2011.00606.x.
To compare, ventilation using intermittent positive pressure ventilation (IPPV) with constant positive end-expiratory pressure (PEEP) and alveolar recruitment manoeuvres (RM) to classical IPPV without PEEP on gas exchange during anaesthesia and early recovery.
Prospective randomized study.
Twenty-four warm-blood horses, weight mean 548 ± SD 49 kg undergoing surgery for colic.
Premedication, induction and maintenance (isoflurane in oxygen) were identical in all horses. Group C (n = 12) was ventilated using conventional IPPV, inspiratory pressure (PIP) 35-45 cmH2O; group RM (n = 12) using similar IPPV with constant PEEP (10 cmH2O) and intermittent RMs (three consecutive breaths PIP 60, 80 then 60 cmH2O, held for 10-12 seconds). RMs were applied as required to maintain arterial oxygen tension (PaO2) at >400 mmHg (53.3 kPa). Physiological parameters were recorded intraoperatively. Arterial blood gases were measured intra- and postoperatively. Recovery times and quality of recovery were measured or scored.
Statistically significant findings were that horses in group RM had an overall higher PaO2 (432 ± 101 mmHg) than those in group C (187 ± 112 mmHg) at all time points including during the early recovery period. Recovery time to standing position was significantly shorter in group RM (49.6 ± 20.7 minutes) than group C (70.7 ± 24.9). Other measured parameters did not differ significantly. The median (range) of number of RMs required to maintain PaO2 above 400 mmHg per anaesthetic was 3 (1-8).
Ventilation using IPPV with constant PEEP and RM improved arterial oxygenation lasting into the early recovery period in conjunction with faster recovery of similar quality. However this ventilation mode was not able to open up the lung completely and to keep it open without repeated recruitment.
This mode of ventilation may provide a clinically practicable method of improving oxygenation in anaesthetized horses.
比较间歇性正压通气（IPPV）联合持续呼气末正压（PEEP）及肺泡复张手法（RM）与传统无PEEP的IPPV在麻醉及早期恢复期间对气体交换的影响。
前瞻性随机研究。
24匹温血马，平均体重548±标准差49kg，接受结肠手术。
所有马匹的术前用药、诱导及维持（氧气中吸入异氟烷）均相同。C组（n = 12）采用传统IPPV通气，吸气压力（PIP）35 - 45cmH₂O；RM组（n = 12）采用类似的IPPV联合持续PEEP（10cmH₂O）及间歇性RM（连续三次呼吸，PIP分别为60、80然后60cmH₂O，持续10 - 12秒）。根据需要应用RM以维持动脉血氧张力（PaO₂）>400mmHg（53.3kPa）。术中记录生理参数。术中和术后测量动脉血气。测量或记录恢复时间及恢复质量。
具有统计学意义的发现是，RM组马匹在包括早期恢复期间的所有时间点的总体PaO₂（432±101mmHg）均高于C组（187±112mmHg）。RM组站立位恢复时间（49.6±20.7分钟）显著短于C组（70.7±24.9）。其他测量参数无显著差异。每次麻醉维持PaO₂高于400mmHg所需RM的中位数（范围）为3（1 - 8）。
IPPV联合持续PEEP及RM通气可改善动脉氧合，持续至早期恢复阶段，且恢复质量相似但恢复更快。然而，这种通气模式无法完全开放肺并使其在无重复复张的情况下保持开放。
这种通气模式可能为改善麻醉马匹的氧合提供一种临床可行的方法。
