Wang C, Nicol M E, Chakrabarti M K, Holdcroft A, Whitwam J G
Department of Anaesthetics, Royal Postgraduate Medical School, Hammersmith Hospital, London, England.
Pediatr Pulmonol. 1993 Dec;16(6):354-7. doi: 10.1002/ppul.1950160606.
We compared high frequency ventilation (HFV) to conventional mechanical ventilation (CMV) under normoxic and normocapnic condition in surfactant depleted rabbits with bilateral pneumothoraces. We hypothesized that lower airway pressures would be required with HFV under these conditions. We applied CMV and HFV in 8 anaesthetized rabbits with a prototype ventilator at frequencies of 30, 100, 200, and 300 cycles/min. A positive end-expiratory pressure (PEEP) just below the pressure sufficient to open the air leak from the pneumothoraces was applied at all frequencies. Airway pressures, gas exchange, heart rate, and mean arterial pressure were recorded. Peak airway pressure decreased significantly from 2.50 to 2.10 kPa when the frequency of ventilation was increased from 30 to 300 cycles/min. There were no significant changes in mean airway pressure, PaO2, arterial pH, heart rate, and mean arterial pressure when HFV was compared to CMV. In conclusion, during HFV peak airway pressures measured at the mouth were decreased. Our ability to maintain adequate gas exchange in the face of ongoing pulmonary air leaks may reflect lower alveolar pressures.
我们在双侧气胸且表面活性物质缺乏的家兔处于常氧和正常碳酸血症状态下，将高频通气（HFV）与传统机械通气（CMV）进行了比较。我们假设在这些条件下HFV所需的气道压力更低。我们使用一台原型呼吸机，以30、100、200和300次/分钟的频率，对8只麻醉的家兔应用了CMV和HFV。在所有频率下均施加了刚好低于足以打开气胸漏气压力的呼气末正压（PEEP）。记录气道压力、气体交换、心率和平均动脉压。当通气频率从30次/分钟增加到300次/分钟时，气道峰值压力从2.50 kPa显著降至2.10 kPa。将HFV与CMV比较时，平均气道压力、PaO2、动脉pH值、心率和平均动脉压均无显著变化。总之，在HFV期间，口腔处测得的气道峰值压力降低。面对持续的肺漏气，我们维持充分气体交换的能力可能反映了较低的肺泡压力。
