Fiedler Mascha O, Simeliunas Emilis, Deutsch B Luise, Diktanaite Dovile, Harms Alexander, Brune Maik, Dietrich Maximilian, Uhle Florian, Weigand Markus A, Kalenka Armin
Department of Anesthesiology, Heidelberg University Hospital, 69120 Heidelberg, Germany.
Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), 69120 Heidelberg, Germany.
J Clin Med. 2021 Jan 15;10(2):306. doi: 10.3390/jcm10020306.
The effects of a moderately elevated intra-abdominal pressure (IAP) on lung mechanics in acute respiratory distress syndrome (ARDS) have still not been fully analyzed. Moreover, the optimal positive end-expiratory pressure (PEEP) in elevated IAP and ARDS is unclear. In this paper, 18 pigs under general anesthesia received a double hit lung injury. After saline lung lavage and 2 h of injurious mechanical ventilation to induce an acute lung injury (ALI), an intra-abdominal balloon was filled until an IAP of 10 mmHg was generated. Animals were randomly assigned to one of three groups (group A = PEEP 5, B = PEEP 10 and C = PEEP 15 cmHO) and ventilated for 6 h. We measured end-expiratory lung volume (EELV) per kg bodyweight, driving pressure (ΔP), transpulmonary pressure (ΔP), static lung compliance (C), oxygenation (P/F ratio) and cardiac index (CI). In group A, we found increases in ΔP (22 ± 1 vs. 28 ± 2 cmHO; = 0.006) and ΔP (16 ± 1 vs. 22 ± 2 cmHO; = 0.007), with no change in EELV/kg (15 ± 1 vs. 14 ± 1 mL/kg) when comparing hours 0 and 6. In group B, there was no change in ΔP (26 ± 2 vs. 25 ± 2 cmHO), ΔP (19 ± 2 vs. 18 ± 2 cmHO), C (21 ± 3 vs. 21 ± 2 cmHO/mL) or EELV/kg (12 ± 2 vs. 13 ± 3 mL/kg). ΔP and ΔP were significantly lower after 6 h when comparing between group C and A (21 ± 1 vs. 28 ± 2 cmHO; = 0.020) and (14 ± 1 vs. 22 ± 2 cmHO; = 0.013)). The EELV/kg increased over time in group C (13 ± 1 vs. 19 ± 2 mL/kg; = 0.034). The P/F ratio increased in all groups over time. CI decreased in groups B and C. The global lung injury score did not significantly differ between groups (A: 0.25 ± 0.05, B: 0.21 ± 0.02, C: 0.22 ± 0.03). In this model of ALI, elevated IAP, ΔP and ΔP increased further over time in the group with a PEEP of 5 cmHO applied over 6 h. This was not the case in the groups with a PEEP of 10 and 15 cmHO. Although ΔP and ΔP were significantly lower after 6 hours in group C compared to group A, we could not show significant differences in histological lung injury score.
中等程度升高的腹内压（IAP）对急性呼吸窘迫综合征（ARDS）肺力学的影响尚未得到充分分析。此外，IAP升高合并ARDS时的最佳呼气末正压（PEEP）尚不清楚。本文中，18只接受全身麻醉的猪遭受了双重打击肺损伤。在进行盐水肺灌洗并进行2小时的损伤性机械通气以诱导急性肺损伤（ALI）后，向腹内气囊充气直至产生10 mmHg的IAP。将动物随机分为三组之一（A组 = PEEP 5、B组 = PEEP 10和C组 = PEEP 15 cmH₂O）并通气6小时。我们测量了每千克体重的呼气末肺容积（EELV）、驱动压（ΔP）、跨肺压（ΔP）、静态肺顺应性（C）、氧合（P/F比值）和心脏指数（CI）。在A组中，比较0小时和6小时时，我们发现ΔP（22±1对28±2 cmH₂O；P = 0.006）和ΔP（16±1对22±2 cmH₂O；P = 0.007）增加，而EELV/千克无变化（15±1对14±1 mL/千克）。在B组中，ΔP（26±2对25±2 cmH₂O）、ΔP（19±2对18±2 cmH₂O）、C（21±3对21±2 cmH₂O/mL）或EELV/千克（12±2对13±3 mL/千克）均无变化。比较C组和A组时，6小时后ΔP和ΔP显著降低（21±1对28±2 cmH₂O；P = 0.020）以及（14±1对22±2 cmH₂O；P = 0.013）。C组中EELV/千克随时间增加（13±1对19±2 mL/千克；P = 0.034）。所有组的P/F比值均随时间增加。B组和C组的CI降低。各组之间的总体肺损伤评分无显著差异（A组：0.25±0.05，B组：0.21±0.02，C组：0.22±0.03）。在这个ALI模型中，在6小时内应用5 cmH₂O的PEEP组中，升高的IAP、ΔP和ΔP随时间进一步增加。在应用10 cmH₂O和15 cmH₂O的PEEP组中并非如此。尽管6小时后C组的ΔP和ΔP与A组相比显著降低，但我们未能显示出组织学肺损伤评分的显著差异。
