Transesophageal echocardiographic assessment of right heart hemodynamics during high-frequency jet ventilation

High-frequency jet ventilation in European and North American institutions: developments and clinical practice

“…However, changing the endotracheal tube exposes the patient with ALI to some risk resulting from discontinuation of ventilation with loss of PEEP and reintubation. To avoid reintubation, special jet adapters have been designed for connection with standard endotracheal tubes (Jet adapter, Ruesch Corp., Kernen, Germany), including additional cannulae for distal pressure monitoring and humidi®cation [33]. High frequency jet ventilation has also been performed successfully via a specialized endotracheal tube (Univent tube, Fuji Systems, Tokyo, Japan) through the lumen of the bronchial blocker for one-lung ventilation during resection of an extensive thoracic tumour [34] or via an injector cannula positioned in the proximal part of the left lumen of a double-lumen Carlen's tube during aortic aneurysm repair [35].…”

“…Each jet stream generated its own gas entrainment from the surrounding air or a humidi®ed and warmed bias¯ow. This technique was applied by means of special jet laryngoscopes with integrated metal injectors during airway surgery [45] or by a special jet adapter for connection to the standard endotracheal tube [33] obviating the need for reintubation in ALI patients [38].…”

“…To determine gas concentrations by side-stream sampling additional channels were integrated into jet catheters and tubes [3,7,9,33,36,48,49]. Because sampling of expiratory gas for carbon dioxide measurement is dif®cult in this open ventilation system and because of the slow response of most CO 2 analysers [50], transcutaneous monitoring of CO 2 was studied in order to adjust ventilator settings and optimize ventilation without the need to measure CO 2 invasively [51].…”

“…Arti®cial ventilation affects right and left ventricular preload and afterload by generation of positive intrathoracic pressures. Fixed rate HFJV, compared with CV with PEEP performed at identical airway pressures, did not cause impairment of cardiovascular function [33,67], but increased cardiac output was observed when HFJV was synchronized to the cardiac cycle in the presence of mitral regurgitation, cardiac tamponade or ARDS [68±70]. However, pressure-limited ventilation, compared with HFJV, did not alter haemodynamics in ALI induced by oleic acid [71].…”

“…While the severity of histological damage has been shown to correlate with the frequency of jet pulses administered, repeated bronchoscopic evaluations need to be performed routinely for early diagnosis [93]. A variety of systems exist to prevent drying out of the airways: one consists of dripping¯uid in front of the jet tip so nebulizing it into the lungs [33], and another uses an humidi®ed bias¯ow or combines HFJV with background CV using a standard humidi®er [38]. Despite intriguing case reports and animal studies describing the typical histopathological pattern of in¯ammation, epithelial erosion, necrosis and cellular in®ltration [14,94], prospective controlled trials failed to demonstrate a higher rate of such lesions in patients treated with HFJV than with CV [7].…”