The Development of an Inspiratory Time Adjustable Transtracheal Jet Ventilator and Evaluation in a Human Adult Trachea-Lung Model / 대한마취과학회지

BACKGROUND: Transtracheal jet ventilation (TTJV) has been used for 'Cannot Ventilate/Cannot Intubate' situation, lefe-saving situations, by simply introducing an IV catheter (angiocatheter) through the cricothyroid membrane. To decrease the occurrence of barotrauma caused by a continuous high pressure oxygen supply while applying TTJV, it would be ideal to have a TTJV system equipped with an inspiration time adjustable function which any currently commercially available TTJV does not have. METHODS: Recently, we made a prototype of an inspiration time adjustable TTJV and measured the corresponding injection volumes and peak inflation pressures according to the changes of oxygen supply pressure and inspiration time using catheters ranging from 14 to 20 G in a simulated human adult trachea-lung model. RESULTS: A 16 G angiocatheter provided 465 +/- 5 ml of injected volume with a peak inflation pressure of 25 cmH2O under a 50 psi oxygen supply at 1 second of inspiration, which would be adequate for an adult tidal volume. When a 14 G catheter was used under the same conditions as above, the injected volume was 1128 +/- 9 ml. All injected volumes were under 310 ml when 18 and 20 G angiocathers were used at variosus driving pressures (10 - 50 psi) and inspiration time (0.5, 0.75, and 1 s). CONCLUSIONS: An inspiration time adjustable TTJV can easily provide enough tidal volume to maintain oxygenation, and could be expected to prevent or reduce barotraumatic complications such as pneumothorax.

Midazolam/Sufentanil vs Etomidate/Sufentanil for the Induction of Anesthesia in Patients with Cardiac Disease / 대한마취과학회지

BACKGROUND: Induction of general anesthesia in patients with cardiac disease must guarantee hemodynamic stability and should result in a satisfactory anesthetic level. The purpose of this study was to analyze the hemodynamic effects of midazolam/sufentanil in comparison with etomidate/sufentanil used for induction of anesthesia in patients with cardiac disease. METHODS: All the patients (n = 30) in the study were about to undergo cardiac surgery and were divided into the midazolam group (n = 15) and etomidate group (n = 15). The induction dose of midazolam was 0.18 mg/kg, etomidate 0.3 mg/kg, vecuronium 0.15 mg/kg, sufentanil 3 microgram/kg, hemodynamics and oxygenation were recorded in the awake state (pre-induction), and 10 minutes after intubation (post-intubation). RESULTS: The etomidate group had a shorter time of anesthetic induction, and some myoclonic movement (13%) was observed. After intubation, reductions of heart rate (13.8%), mean arterial pressure (18.4%), cardiac index (14.8%), left ventricular stroke work index (9.7 - 38.5%), oxygen delivery index (7.43%), oxygen consumption index (10.3%), and Qs/Qt (25.6%), and an increase in central venous pressure (0 - 50%) were observed in both groups. Decreases in right ventricular stroke work index and mean arterial pressure were observed in the midazolam group, but no change in right ventricular stroke work index and a decrease in mean arterial pressure was observed in the etomidate group. In the midazolam group the values of right ventricular stroke work index and mean arterial pressure were significantly lower than in the etomidate group. The heart rate of the midazolam group in patients with CABG were significantly lower than in the etomidate group. CONCLUSIONS: The results of this study shows that etomidate was found to be as reliable and effective an agent for induction as midazolam.