呼吸机气体输送波形对平台压和峰压-平台压梯度的测定有显著影响。

Ventilator gas delivery wave form substantially impacts plateau pressure and peak-to-plateau pressure gradient determination.

作者信息

Maung Adrian Anthony, Johnson Dirk C, Luckianow Gina M, Kaplan Lewis J

机构信息

From the Department of Surgery (A.A.M., D.C.J., G.M.L.), Section of Trauma, Surgical Critical Care and Surgical Emergencies, Yale School of Medicine, New Haven, Connecticut; and Division of Trauma, Surgical Critical Care and Emergency Surgery (L.J.K.), Perelman School of Medicine, University of Pennsylvania; and Department of Surgery (L.J.K.), Philadelphia Veterans Affairs Medical Center, Philadelphia, Pennsylvania.

出版信息

J Trauma Acute Care Surg. 2015 May;78(5):976-9. doi: 10.1097/TA.0000000000000615.

DOI:10.1097/TA.0000000000000615

PMID:25909418

Abstract

BACKGROUND

To determine whether plateau pressure (Pplat) measurement is lowered and peak airway pressure (Pawpeak)-to-Plat gradient is increased by measurement on a decelerating compared with square gas delivery wave form.

METHODS

Prospective before and after study of mechanically ventilated injured and critically ill patients in an adult surgical intensive care unit. Pplat, Pawpeak, and Pawpeak-to-Pplat gradient were measured on decelerating and square gas delivery wave forms.

RESULTS

Pplat and other routine ventilator parameters were measured in 82 (47 trauma, 35 emergency general surgery) consecutive convenience sampled adult intensive care unit patients on decelerating and then square gas delivery wave forms. Peak gas flow was fixed at 40 L/min; all other parameters (rate, tidal volume, positive end-expiratory pressure) were held constant. All patients were managed on assist control volume cycled ventilation using fentanyl and midazolam or propofol; no neuromuscular blockade was used. Patients with Pawpeak more than 35 cm H2O were excluded. Comparing decelerating with square gas delivery, mean Pawpeak was lower (25.1 ± 2.3 cm H2O vs. 33.1 ± 2.1 cm H2O; p < 0.0001) and mean Pplat was lower (21.3 ± 1.9 cm H2O vs. 24.8 ± 2.5 cm H2O; p < 0.0001), resulting in a decreased Pawpeak-to-Pplat gradient (3.8 ± 2.1 vs. 8.3 ± 2.3; p < 0.0001).

CONCLUSION

Changing from a decelerating to a square gas delivery wave form significantly increases Pplat and Pawpeak, thereby increasing the Pawpeak-to-Pplat gradient. This increase may prompt unwarranted therapy aimed at reducing the gradient to its normal value of 4 cm H2O pressure or less. Conversely, patients with a high Pawpeak on a square wave form may benefit from transitioning to a decelerating wave form before changing ventilation parameters.

LEVEL OF EVIDENCE

Diagnostic study, level III.

摘要

背景

确定与方波气体输送波形相比，在减速波形上进行测量时，平台压（Pplat）测量值是否降低，以及气道峰压（Pawpeak）与平台压的梯度是否增加。

方法

对一家成人外科重症监护病房中接受机械通气的受伤和危重症患者进行前瞻性前后对照研究。在减速和方波气体输送波形上测量Pplat、Pawpeak以及Pawpeak与Pplat的梯度。

结果

对82例（47例创伤患者，35例急诊普通外科患者）连续方便抽样的成人重症监护病房患者，先在减速波形然后在方波气体输送波形上测量Pplat和其他常规通气参数。峰值气流固定为40 L/分钟；所有其他参数（频率、潮气量、呼气末正压）保持恒定。所有患者均采用芬太尼和咪达唑仑或丙泊酚进行辅助控制容量切换通气治疗；未使用神经肌肉阻滞剂。排除Pawpeak超过35 cm H2O的患者。将减速波形与方波气体输送波形进行比较，平均Pawpeak较低（25.1±2.3 cm H2O对33.1±2.1 cm H2O；p<0.0001），平均Pplat较低（21.3±1.9 cm H2O对24.8±2.5 cm H2O；p<0.0001），导致Pawpeak与Pplat的梯度降低（3.8±2.1对8.3±2.3；p<0.0001）。