立即采用呼气末正压（PEEP）进行正压通气可提高绵羊烟雾吸入性损伤的存活率。

Immediate positive pressure ventilation with positive end-expiratory pressure (PEEP) improves survival in ovine smoke inhalation injury.

作者信息

Cox C S, Zwischenberger J B, Traber D L, Minifee P K, Navaratnam N, Haque A K, Herndon D N

机构信息

Department of Surgery, University of Texas Medical Branch, Galveston 77550.

出版信息

J Trauma. 1992 Dec;33(6):821-7. doi: 10.1097/00005373-199212000-00005.

DOI:10.1097/00005373-199212000-00005

PMID:1474622

Abstract

BACKGROUND

The purpose of this study was to compare the effects of immediate initiation of positive pressure ventilation (PPV) with positive end-expiratory pressure (PEEP) versus the initiation of PPV with PEEP only after hypoxemia ensued following severe smoke inhalation injury.

METHODS

We prospectively evaluated chronically instrumented adult sheep treated with immediate versus delayed PPV with PEEP and compared oxygen requirements, hemodynamics, pleural fluid formation, postinjury survival, and tracheobronchial pathologic processes among groups. The immediate group (group I; smoke, n = 6; sham, n = 2) underwent tracheostomy and bilateral chest tube placement before they received inhalation injury. They were then immediately placed on PPV with PEEP (12 cm H2O). The animals in the delayed group (group D) (n = 6) were placed on PPV with PEEP when arterial hypoxemia (PaO2 < 80 mm Hg [11.2 kPa] on 0.4 FIO2) or respiratory distress developed.

RESULTS

Groups were matched for smoke exposure and peak carboxyhemoglobin. Both groups developed a characteristic decrease in PaO2/FIO2 ratio. Initiation of PPV + PEEP improved PaO2 in the delayed group (69 +/- 7 to 126 +/- 21 mm Hg [9.2 +/- 0.9 to 16.7 +/- 2.8 kPa]). Pleural fluid output was greater in the immediate group compared with the delayed group (1559 +/- 415 vs. 426 +/- 236 mL). At 96 hours after injury five of six animals in the delayed group had died. In contrast, six of six animals in the immediate smoke group survived 96 hours (p < 0.05 versus delayed group). The immediate group had fewer and less extensive tracheobronchial casts at necropsy.

CONCLUSIONS

Immediate PPV + PEEP did not prevent the development of hypoxia and was associated with increased pleural fluid formation. Death within 96 hours in the delayed group was the result of respiratory failure aggravated by bronchial cast formation despite vigorous pulmonary toilet. Early positive pressure ventilation with PEEP, preferably initiated immediately after the inhalation insult, significantly increases short-term survival and is associated with decreased tracheobronchial cast formation in this ovine model of severe smoke inhalation injury.

摘要

背景

本研究的目的是比较立即开始使用呼气末正压（PEEP）的正压通气（PPV）与仅在严重烟雾吸入性损伤后出现低氧血症后才开始使用PEEP的PPV的效果。

方法

我们前瞻性地评估了长期植入仪器的成年绵羊，分别接受立即与延迟使用PEEP的PPV治疗，并比较了各组之间的氧气需求、血流动力学、胸腔积液形成、损伤后存活率以及气管支气管病理过程。立即治疗组（I组；烟雾吸入组，n = 6；假手术组，n = 2）在接受吸入性损伤前进行气管切开术和双侧胸腔闭式引流管置入。然后立即给予PEEP（12 cm H₂O）的PPV治疗。延迟治疗组（D组）（n = 6）在出现动脉低氧血症（在0.4的吸入氧分数下，动脉血氧分压[PaO₂]<80 mmHg [11.2 kPa]）或呼吸窘迫时给予PEEP的PPV治疗。

结果

两组在烟雾暴露和峰值碳氧血红蛋白水平上相匹配。两组的PaO₂/吸入氧分数比值均出现特征性下降。延迟治疗组开始使用PPV + PEEP后，PaO₂有所改善（从69±7 mmHg [9.2±0.9 kPa]升至126±21 mmHg [16.7±2.8 kPa]）。立即治疗组的胸腔积液量比延迟治疗组更多（1559±415 mL vs. 426±236 mL）。损伤后96小时，延迟治疗组6只动物中有5只死亡。相比之下，立即烟雾吸入组的6只动物中有6只存活了96小时（与延迟治疗组相比，p < 0.05）。立即治疗组在尸检时气管支气管铸型较少且范围较小。

结论

立即使用PPV + PEEP并不能预防低氧血症的发生，且与胸腔积液形成增加有关。延迟治疗组在96小时内死亡是由于尽管积极进行肺部灌洗，但支气管铸型形成加重了呼吸衰竭。在这个严重烟雾吸入性损伤的绵羊模型中，早期使用PEEP进行正压通气，最好在吸入损伤后立即开始，可显著提高短期存活率，并与气管支气管铸型形成减少有关。