Airway eicosanoids in acute severe respiratory syncytial virus bronchiolitis

We prospectively studied the levels of eicosanoids in intubated patients with severe bronchiolitis and compared them to electively intubated non-infected infants. LeukotrieneE(4) (LTE(4)), leukotrieneB(4) (LTB(4)), and prostaglandinE(2) (PGE(2)) levels were significantly increased (P <.01) from endotracheal (ET) aspirates of infants with bronchiolitis compared with controls, as were urinary LTE(4) levels (P <.001). We conclude that eicosanoids are increased in the tracheal aspirates and urine of children with bronchiolitis.     

Endotracheal tube intraluminal diameter narrowing after mechanical ventilation: use of acoustic reflectometry

Objective To quantify the incidence and degree of endotracheal tube intraluminal obstruction after mechanical ventilation and its relation to time of intubation.Design Prospective observational study.Setting A 14-bed medical-surgical intensive care unit at a university-affiliated teaching hospital.Patients Ninety-four endotracheal tubes used in 80 patients requiring mechanical ventilation for more than 12 h.Interventions and results Acoustic reflectometry was performed in every endotracheal tube after patient extubation to measure its volume reduction. The intraluminal volumes of used endotracheal tubes in mechanically ventilated patients were significantly lower than those of unused tubes of the same size (5.52±0.92 ml³ versus 6.54±0.79 ml³, p<0.05). The mean difference in endotracheal tube segment volumes was 15.2% (range 0–66%). Volume reduction was above 10% in 60.8% of the tubes. In 22% of endotracheal tubes the remaining inner diameter was less than 7 mm. Reduction below this figure was less frequent (9.3%) in tubes 8 mm or more (p<0.05). The percentage of endotracheal tube volume reduction was not associated with the duration of intubation (r=–0.09, p= n.s.) Peak pressure measured before extubation did not predict obstruction (r=0.11, p= n.s.)Conclusions Inadvertent endotracheal tube obstruction was common in patients requiring mechanical ventilation and may be significant as early as at 24 h. Moderate obstruction in endotracheal tube lumens should be suspected in cases of difficulties in weaning, even in patients who were ventilated for less than 1 day.Presented, in part, at the 16^th European Society Intensive Care Medicine Congress, Amsterdam, October 2003.     

Elimination of ventilator dead space during synchronized ventilation in premature infants

BACKGROUND: Mainstream airflow sensors used in neonatal ventilators to synchronize mechanical breaths with spontaneous inspiration and measure ventilation increase dead space and may impair carbon dioxide (CO(2)) elimination. OBJECTIVE: To evaluate a technique consisting of a continuous gas leakage at the endotracheal tube (ETT) adapter to wash out the airflow sensor for synchronization and ventilation monitoring without CO(2) rebreathing in preterm infants. DESIGN: Minute ventilation (V'(E)) by respiratory inductance plethysmography, end-inspiratory and end-expiratory CO(2) by side-stream microcapnography, and transcutaneous CO(2) tension (TcPCO(2)) were measured in 10 infants (body weight, 835+/-244 g; gestational age, 26+/-2 weeks; age, 19+/-9 days; weight, 856+/-206 g; ventilator rate, 21+/-6 beats/min; PIP, 16+/-1 centimeters of water (cmH(2)O); PEEP, 4.2+/-0.4 cmH(2)O; fraction of inspired oxygen (FIo(2)), 0.26+/-0.6). The measurements were made during four 30-minute periods in random order: IMV (without airflow sensor), IMV+Sensor, SIMV (with airflow sensor), and SIMV+Leak (ETT adapter continuous leakage). RESULTS: Airflow sensor presence during SIMV and IMV+Sensor periods resulted in higher end-inspiratory and end-expiratory CO(2), Tcpco(2), and spontaneous V'(E) compared with IMV. These effects were not observed during SIMV+Leak. CONCLUSIONS: The significant physiologic effects of airflow sensor dead space during synchronized ventilation in preterm infants can be effectively prevented by the ETT adapter continuous leakage technique.     

Mechanism of endotracheal tube movement with change of head position in the neonate

The mechanism of alteration of endotracheal tube position with movement of the head and neck in the neonate was studied in a term newborn cadaver. The infant was intubated and serial radiographs were obtained with the head and neck in different positions. We propose that the skull acts as a lever arm from the anterior end of the maxilla to the first cervical vertebra. The fulcrum for movement of this lever arm is the upper cervical spine. Movement of the endotracheal tube in the trachea is directed by the maxillocervical lever arm when the skull and upper cervical spine are flexed, extended, or rotated.     

53例新生儿气管插管的护理

目的：探讨新生儿气管插管的护理对策,以提高抢救的成功率。方法：对我科两年新生儿气管插管进行回顾性分析,对比两年的气管插管护理效果。结果：实行了规范的护理后明显降低了呼吸机相关肺炎（vap）的发生。结论：规范新生儿气管插管的护理对策,可明显降低气管插管的相关并发症。     

呼吸机治疗重症哮喘疗效观察

目的探讨呼吸机治疗重症哮喘的疗效。方法将24例重症哮喘患者分为2组，对照组采用常规治疗，试验组在常规治疗的基础上，加用气管插管并使用呼吸机治疗。根据病情调整参数，并比较2组患者在治疗3天的临床症状和各化验指标。结果试验组有效率高于对照组。结论在常规治疗的基础上加用呼吸机治疗，可提高治疗重症哮喘的疗效。     

Effect of endotracheal suctioning on arterial blood gases in children

The occurrence of hypoxia during endotracheal tube suctioning and its prevention was examined in 25 hemodynamically stable and non-cyanosed pediatric patients. In each patient 4 suction and treatment protocols were studied: 1. pre- and post-suction arterial blood gases (ABG) with no treatment (control). 2. ABG with pre-suction oxygenation. 3. ABG with presuction hyperinflation. 4. ABG with postsuction hyperinflation. With no presuction treatment the PO₂ and saturation fell significantly after suctioning from control level of 116.6±9.4 mmHg to 93±9.3 mmHg post-suction and 97.2±0.4% to 92.8±1.4% (p<0.001) respectively. In 6 patients with low but adequate pre-suction PO₂, hypoxic levels (PO₂<60 mmHg) were found post-suction. The significant fall in PO₂ was completely prevented by pre-suction oxygenation. Post-suction hyperinflation induced a rapid return of the PO₂ to control levels. These results suggest that severe hypoxia might occur during endotracheal suctioning and can be prevented by pre-oxygenation. We recommend 1 min oxygenation with FiO₂ 1.0 prior to suctioning procedures and intermittent hyperinflation with 100% oxygen during repeated endotracheal suction passes to prevent hypoxia, especially in children in respiratory failure who already have low or borderline pre-suction PO₂.     

佩尔地平对气管拔管期间心血管应激反应的平抑作用

目的探讨气管拔管期间血流动力学的变化及佩尔地平的平抑作用。方法选择ASAⅠ～Ⅱ级24例行全麻手术患者,随机分为两组,即C组(对照组,12例)和T组(试验组,12例)。C组在停止吸入麻醉药后不用任何药物;T组在停止吸入麻醉药后10min静脉注射佩尔地平10μg/kg,然后以3μg·kg-1/min持续微泵静推。分别监测停吸麻醉药时(t0),停药后10min(t1)、20min(t2)和气管拔管时(t3)等时点的HR,SBP,DBP,MAP,SpO2,PETCO2。试停吸氧5min,若SpO2>95%则持续吸入空气。结果①C组t2、t3时点的HR,SBP,DBP,MAP均分别高于同组的t0及t1时点各值;也高于T组的上述各值(P<0.05);②T组各时点的血流动力学指标无显著变化。结论①气管拔管期间心血管的应激反应明显增强;②佩尔地平可明显平抑气管拔管期间的心血管应激反应。     

Comparison of the Macintosh laryngoscope and blind intubation via the iGEL for Intubation With C-spine immobilization: A Randomized,crossover, manikin trial

Introduction

Endotracheal intubation (ETI) using a Macintosh laryngoscope (MAC) requires the head to be positioned in a modified Jackson position, slightly reclined and elevated. Intubation of trauma patients with an injured neck or spine is therefore difficult, since the neck usually cannot be turned or is already immobilized in order to prevent further injury. The iGEL supraglottic airway seems optimal for such conditions due to its blind insertion without the need of a modified Jackson position.