A prototype small-bore ventilation catheter with a cuff: cuff inflation optimizes ventilation with the Ventrain.

BACKGROUND: Ventilation through small-diameter tubes typically precludes use of a cuff as this will impede the necessary passive outflow of gas alongside the tube's outer surface. Ventrain assists expiration and enables oxygenation and normoventilation through small-bore cannulas or catheters, particularly in obstructed airways. A small-bore ventilation catheter (SBVC; 40 cm long, 2.2 mm inner diameter) with a separate pressure monitoring lumen and a cuff was developed. Efficacy of oxygenation and ventilation with Ventrain through this catheter was investigated in sealed and open airways in a porcine cross-over study. METHODS: Six pigs were ventilated with Ventrain (15 l/min oxygen, frequency 30 breaths per min, I : E-ratio 1 : 1) through the SBVC, both with the cuff inflated and deflated. Prior to each test they were ventilated conventionally until steady state was achieved. RESULTS: With an inflated cuff, PaO2 rose instantly and remained elevated (median [range] PaO2 61 [52-69] kPa after 30 min; P = 0.027 compared to baseline). PaCO2 remained stable at 4.9 [4.2-6.2] kPa. After cuff deflation, PaO2 was significantly lower (9 [5-28] kPa at 10 min, P = 0.028) and interventional ventilation had to be stopped prematurely in five pigs as PaCO2 exceeded 10.6 kPa. Pulmonary artery pressures increased markedly in these pigs. Intratracheal pressures were kept between 5 and 20 cmH2 O with the cuff inflated, but never exceeded 2 cmH2 O after cuff deflation. CONCLUSION: The SBVC combines the benefits of a small diameter airway and a cuff. Cuff inflation optimizes oxygenation and ventilation with Ventrain.

Ventilation via the 2.4 mm internal diameter Tritube® with cuff - new possibilities in airway management.

BACKGROUND: A small tube may facilitate tracheal intubation and improve surgical access. We describe our initial experience with the Tritube® that is a novel cuffed endotracheal tube with a 2.4 mm internal diameter. METHODS: The Tritube® was used in seven adult Ear-Nose-and Throat surgical patients with airway narrowing or whose surgical access was facilitated by this small-bore endotracheal tube. Ventilation through Tritube® is performed with the manually operated Ventrain® -ventilator that allows active suctioning during expiration, therefore facilitating normoventilation through small diameter airways. RESULTS: The small diameter of Tritube® seemed to improve glottis visualisation during intubations and gave excellent working conditions for surgery. Two patients were intubated awake with a flexible scope and a guide wire or with an angulated video laryngoscope. One patient had almost complete glottic occlusion that just allowed for passage of the Tritube® . Adequate ventilation was achieved in all patients and intratracheal pressure was kept between 5 and 20 cm H2 O. The tube was well tolerated after emergence from anaesthesia and kept intratracheally in five awake patients in the post-operative recovery unit, in one case for more than 1 h. Ventilating with Ventrain® through Tritube® demands meticulous breath by breath measurement and adjustment of the intratracheal pressure. CONCLUSION: The 2.4 mm internal diameter Tritube® seems to facilitate tracheal intubation and to provide unprecedented view of the intubated airway during oral, pharyngeal, laryngeal or tracheal procedures in adults. This technique has the potential to replace temporary tracheostomy, jet-ventilation or extra-corporal membrane oxygenation in selected patients.