Faculty of Medicine and Health Sciences, Ghent University, Sint-Pietersnieuwstraat 25, Ghent, Belgium.
Faculty of Medicine and Health Sciences, Ghent University, Sint-Pietersnieuwstraat 25, Ghent, Belgium; Department of Emergency Medicine, Ghent University Hospital, Corneel Heymanslaan 10, Ghent, Belgium.
Resuscitation. 2024 Jul;200:110242. doi: 10.1016/j.resuscitation.2024.110242. Epub 2024 May 15.
In patients undergoing cardiopulmonary resuscitation (CPR) after an Out-of-Hospital Cardiac Arrest (OHCA), intrathoracic airway closure can impede ventilation, adversely affecting patient outcomes. This explorative study investigates the evolution of intrathoracic airway closure by analyzing the lower inflection point (LIP) during the inspiration phase of CPR, aiming to identify the potential thresholds for alveolar recruitment.
Eleven OHCA patients undergoing CPR with endotracheal intubation and manual bag ventilation were included. Flow and pressure measurements were obtained using Sensirion SFM3200AW and Wika CPT2500 sensors attached to the endotracheal tube, connected to a Surface Go Tablet for data collection. Flow data was analyzed in Microsoft Excel, while pressure data was processed using the Wika USBsoft2500 application. Analysis focused on the inspiration phase of the first 6-8 breaths, with an additional 2 breaths recorded and analyzed at the end of CPR.
Across the cohort, the median tidal volume was 870.00 milliliter (mL), average flow was 31.90 standard liters per minute (slm), and average pressure was 17.21 cmHO. The calculated average LIP was 31.47 cmHO. Most cases (72.7%) exhibited a negative trajectory in LIP evolution during CPR, with 2 cases (18.2%) showing a positive trajectory and 1 case remaining inconclusive. The average LIP in the first 8 breaths was significantly higher than in the last 2 breaths (p = 0.018). No significant correlation was found between average LIP and return of spontaneous circulation (ROSC), compression depth, frequency, or end-tidal CO (EtCO). However, a significant negative correlation was observed between the average LIP of the last 2 breaths and CPR duration (p = 0.023).
LIP calculation in low-flow ventilations using the novel mathematical method yielded values consistent with those reported in the literature.
DISCUSSION/CONCLUSION: These explorative data demonstrate a predominantly negative trajectory in LIP evolution during CPR, suggesting potential challenges in maintaining airway patency. Limitations include a small sample size and sensor recording issues. Further research is warranted to explore the evolution of LIP and its implications for personalized ventilation strategies in CPR.
在院外心脏骤停（OHCA）后进行心肺复苏（CPR）的患者中，胸内气道闭合会阻碍通气，对患者预后产生不利影响。本探索性研究通过分析 CPR 吸气相的下拐点（LIP）来研究胸内气道闭合的演变，旨在确定肺泡复张的潜在阈值。
纳入 11 例接受心肺复苏并进行气管插管和手动气囊通气的 OHCA 患者。使用 Sensirion SFM3200AW 和 Wika CPT2500 传感器在气管内导管上获得流量和压力测量值，连接到 Surface Go Tablet 进行数据采集。在 Microsoft Excel 中分析流量数据，而在 Wika USBsoft2500 应用程序中处理压力数据。分析重点是前 6-8 次呼吸的吸气相，在 CPR 结束时记录并额外分析 2 次呼吸。
整个队列的中位潮气量为 870.00 毫升（mL），平均流量为 31.90 标准升/分钟（slm），平均压力为 17.21 厘米水柱（cmHO）。计算得出的平均 LIP 为 31.47 cmHO。大多数情况下（72.7%）在 CPR 期间 LIP 演变呈负轨迹，2 例（18.2%）呈正轨迹，1 例不确定。前 8 次呼吸的平均 LIP 明显高于后 2 次呼吸（p=0.018）。平均 LIP 与自主循环恢复（ROSC）、按压深度、频率或呼气末 CO（EtCO）之间无显著相关性。然而，最后 2 次呼吸的平均 LIP 与 CPR 持续时间呈显著负相关（p=0.023）。
使用新的数学方法在低流量通气中计算 LIP 产生的值与文献中报告的值一致。
讨论/结论：这些探索性数据表明，在 CPR 期间 LIP 演变呈主要负轨迹，表明维持气道通畅可能存在挑战。局限性包括样本量小和传感器记录问题。需要进一步研究以探索 LIP 的演变及其对 CPR 中个性化通气策略的影响。
