Transtracheal open ventilation in respiratory care of patients after cardiovascular surgery.

Abstract

vascular surgery and had already received minitracheotomy for drainage of airway sputum. To examine whether TOV was useful during the postextubation period, at the ICU of Osaka Prefectural General Hospital we retrospectively compared the results with those from patients who had received only minitracheotomy. Using Seldinger’s method, a 4-mm internal diameter cannula (Mini-Trach II, SIMS Portex, Hythe, UK) was placed through the cricothyroid membrane. Ventilatory settings were: assist/control mode; PCV 35–40 cmH2O, inspiratory time 0.6–0.8 s, triggering sensitivity –0.5 cmH2O, and positive end-expiratory pressure 0 cmH2O. The assist/control rate was set at 2 breaths/min, thus ensuring that all breaths would be patient triggered and fully synchronized with the patient’s inspiratory effort. Informed consent for receiving TOV was obtained from all patients. Extubation failure was defined as reintubation within 72 h of extubation or at the end of TOV. Categorical values were analyzed using the Fisher’s exact probability test and continuous variables were analyzed using independent Student’s t test. A p value below 0.05 was set as the limit of significance. Of the 206 patients 12 received minitracheotomy and TOV between January 1998 and June 1999. We retrospectively screened 206 patients between July 1995 and December 1996; ten of these patients received minitracheotomy (control group; Table 1). Duration of TOV was 61±34 h, administered for a period of 4.7±1.7 days without major complications. Four of ten patients were reintubated in the control group and none in the TOV group; the reintubation rate was significantly lower in the TOV group. There were no significant differences between the two groups in duration of mechanical ventilation, oral intubation, or ICU stay. TOV was applied for several days without major complications. Application of TOV to patients following extubation seemed to reduce the need for reintubation. Various conditions indicate the need for reintubation, but high upper-airway resistance due to upper airway edema often leads to large work of breathing and extubation failure. Although minitracheotomy can effectively resolve problems with sputum retention, the minitracheotomy tube itself may sometimes increase upper airway resistance. Results from the previous lung model study suggest that TOV reduces patient’s inspiratory work as effectively as noninvasive positive ventilation. TOV continues to provide inspiratory assistance when upper airway resistance is higher when, under similar conditions, the assistance provided by noninvasive positive ventilation would decrease [4]. TOV may be useful for avoiding the need for reintubation. C O R R E S P O N D E N C E