目的  本研究旨在探讨不同俯卧位通气（PPV）时间对重症肺炎合并胃肠功能障碍患者肠内营养耐受性的影响。方法  选择2020年7月—2023年7月在天津市人民医院重症监护病房（MICU）治疗的80例重症肺炎合并胃肠功能障碍患者为研究对象, 按每日PPV时间分为长时组（≥12 h, n=40）和短时组（<12 h, n=40）。比较两组患者一般资料、氧合指数、胃肠功能指标[腹内压、血清促胃液素（GAS）和血管活性肠肽（VIP）]、肠内营养达标率、胃肠并发症率等。结果  短时组治疗后, 1 d、3 d、5 d氧合指数为（189.93±33.72）、（247.53±63.01）、（325.03±58.11）mmHg,高于长时组的（161.63±36.88）、（191.83±57.65）、（267.95±46.25）mmHg,均P<0.05; 胃残留量为（29.00±7.92）、（19.75±4.45）、（11.00±1.87） mL低于长时组的（75.03±23.29）、（53.13±11.99）、（21.70±5.52） mL, 均P<0.05。短时组治疗后腹内压[（8.53±2.05）mmHg vs （9.75±2.05） mmHg]、VIP水平[（61.14±7.63） vs （67.49±4.43） pg/mL]低于长时组,GAS水平[（65.02±8.84） vs （54.22±9.21）pg/mL]升高（均P<0.05）。短时组总胃肠并发症发生率（7.50%）低于长时组（25.00%）, P=0.034。结论  对于重症肺炎合并胃肠功能障碍患者,每日PPV时间≤12 h可改善氧合并降低胃肠并发症风险, 可能与减轻腹压、调节胃肠激素分泌及提升肠内营养耐受性相关。

      Objective To explore the effect of different duration of prone position ventilation（PPV）on enteral nutritional tolerance in patients with severe pneumonia combined with gastrointestinal dysfunction．Methods A total of 80 patients with severe pneumonia complicated by gastrointestinal dysfunction were treated in the Medical Intensive Care Unit（MICU）of a hospital from July 2020 to July 2023, and were selected as the research subjects．They were divided into the long-duration group（≥12 hours, n=40）and the short-duration group（<12 hours, n=40）according to the daily duration of PPV．The general data, oxygenation index, gastrointestinal function indicators（intra-abdominal pressure, serum gastrin[GAS] and vasoactive intestinal peptide[VIP]）, enteral nutrition achievement rate, and gastrointestinal complications of the two groups were compared．Results The oxygenation index of the short-duration group at 1 d, 3 d,a nd 5 d after treatment（[189.93±33.72], [247.53±63.01], and[325.03±58.11] mmHg, respectively）was significantly higher than that of the long-duration group（[161.63±36.88], [191.83±57.65], and[267.95±46.25] mmHg,respectively, all P<0.05）．The gastric residual volume of the short-duration group（[29.00±7.92], [19.75±4.45], and[11.00±1.87] mL, respectively）was significantly lower than that of the long-duration group（[75.03±23.29], [53.13±11.99], and[21.70±5.52] mL, respectively, all P<0.05）．The intra-abdominal pressure（[8.53±2.05] vs [9.75±2.05] mmHg）and VIP level（[61.14±7.63] vs [67.49±4.43] pg/mL）of the short-duration group after treatment were significantly lower than those of the long-duration group, while the GAS level（[65.02±8.84] vs [54.22±9.21] pg/mL）was significantly higher（all P<0.05）．The total incidence of gastrointestinal complications in the short-duration group（7.50%）was significantly lower than that in the long-duration group（25.00%, P=0.034）．Conclusions For patients with severe pneumonia complicated by gastrointestinal dysfunction, a daily duration of PPV within 12 hours can improve oxygenation and reduce the risk of gastrointestinal complications, which may be related to the reduction of intra-abdominal pressure, regulation of gastrointestinal hormone secretion, and improvement of enteral nutrition tolerance．