de Jager Pauline, Burgerhof Johannes G M, Koopman Alette A, Markhorst Dick G, Kneyber Martin C J
Department of Paediatrics, Division of Paediatric Critical Care Medicine, Beatrix Children's Hospital, University Medical Center Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands.
Department of Epidemiology, University Medical Center Groningen, Groningen, The Netherlands.
Ann Intensive Care. 2020 Nov 18;10(1):153. doi: 10.1186/s13613-020-00771-8.
Titration of the continuous distending pressure during a staircase incremental-decremental pressure lung volume optimization maneuver in children on high-frequency oscillatory ventilation is traditionally driven by oxygenation and hemodynamic responses, although validity of these metrics has not been confirmed.
Respiratory inductance plethysmography values were used construct pressure-volume loops during the lung volume optimization maneuver. The maneuver outcome was evaluated by three independent investigators and labeled positive if there was an increase in respiratory inductance plethysmography values at the end of the incremental phase. Metrics for oxygenation (SpO, FiO), proximal pressure amplitude, tidal volume and transcutaneous measured pCO (pCO) obtained during the incremental phase were compared between outcome maneuvers labeled positive and negative to calculate sensitivity, specificity, and the area under the receiver operating characteristic curve. Ventilation efficacy was assessed during and after the maneuver by measuring arterial pH and PaCO. Hemodynamic responses during and after the maneuver were quantified by analyzing heart rate, mean arterial blood pressure and arterial lactate.
41/54 patients (75.9%) had a positive maneuver albeit that changes in respiratory inductance plethysmography values were very heterogeneous. During the incremental phase of the maneuver, metrics for oxygenation and tidal volume showed good sensitivity (> 80%) but poor sensitivity. The sensitivity of the SpO/FiO ratio increased to 92.7% one hour after the maneuver. The proximal pressure amplitude showed poor sensitivity during the maneuver, whereas tidal volume showed good sensitivity but poor specificity. PaCO decreased and pH increased in patients with a positive and negative maneuver outcome. No new barotrauma or hemodynamic instability (increase in age-adjusted heart rate, decrease in age-adjusted mean arterial blood pressure or lactate > 2.0 mmol/L) occurred as a result of the maneuver.
Absence of improvements in oxygenation during a lung volume optimization maneuver did not indicate that there were no increases in lung volume quantified using respiratory inductance plethysmography. Increases in SpO/FiO one hour after the maneuver may suggest ongoing lung volume recruitment. Ventilation was not impaired and there was no new barotrauma or hemodynamic instability. The heterogeneous responses in lung volume changes underscore the need for monitoring tools during high-frequency oscillatory ventilation.
在高频振荡通气的儿童中，进行阶梯式递增-递减压力肺容积优化操作时，连续扩张压力的滴定传统上由氧合和血流动力学反应驱动，尽管这些指标的有效性尚未得到证实。
在肺容积优化操作期间，使用呼吸感应体积描记法值构建压力-容积环。该操作结果由三名独立研究人员评估，如果在递增阶段结束时呼吸感应体积描记法值增加，则标记为阳性。比较标记为阳性和阴性的操作结果在递增阶段获得的氧合指标（SpO₂、FiO₂）、近端压力振幅、潮气量和经皮测量的pCO₂（tcPCO₂），以计算敏感性、特异性和受试者操作特征曲线下面积。通过测量动脉pH值和PaCO₂评估操作期间及之后的通气效果。通过分析心率、平均动脉血压和动脉乳酸来量化操作期间及之后的血流动力学反应。
41/54例患者（75.9%）操作结果为阳性，尽管呼吸感应体积描记法值的变化非常不均匀。在操作的递增阶段，氧合指标和潮气量显示出良好的敏感性（>80%）但特异性较差。操作后1小时，SpO₂/FiO₂比值的敏感性增加到92.7%。操作期间近端压力振幅显示出较差的敏感性，而潮气量显示出良好的敏感性但特异性较差。操作结果为阳性和阴性的患者中，PaCO₂均降低，pH值均升高。该操作未导致新的气压伤或血流动力学不稳定（年龄校正心率增加、年龄校正平均动脉血压降低或乳酸>2.0 mmol/L）。
肺容积优化操作期间氧合无改善并不表明使用呼吸感应体积描记法量化的肺容积没有增加。操作后1小时SpO₂/FiO₂增加可能提示肺容积持续募集。通气未受损，且没有新的气压伤或血流动力学不稳定。肺容积变化的不均匀反应强调了高频振荡通气期间监测工具的必要性。
