Deep propofol sedation for vacuum-assisted bite-block immobilization in children undergoing proton radiation therapy of cranial tumors.

BACKGROUND: Vacuum-assisted bite-block immobilization of the head is a reliable technique for reproducible precise head positioning as used for proton radiation in adults. We report preliminary experience using deep propofol sedation without an artificial airway in children undergoing proton radiation of cranial tumors requiring vacuum-assisted bite-block immobilization. METHODS: Sedation was started with a bolus of i.v. midazolam followed by repeated small boluses of propofol as required to tolerate bite-block insertion and patient positioning. Sedation was maintained by continuous propofol infusion until removal of the bite block. Oxygen was administered by a nasal cannula. SpO2, endtidal CO2 taken at the nose and respiratory adverse events such as coughing, bucking, airway obstruction, regurgitation or aspiration were recorded. Data are mean+/-sd. RESULTS: Ten children aged 2.6+/-0.8 years were treated to date. For each child, cumulative 26.7+/-1.9 radiation fractions were administered. Propofol dose administered for induction, bite-block insertion and patient positioning was 3.9+/-0.5 mg.kg(-1). Time from insertion to removal of the bite block lasted 48.3+/-6.2 min. Endtidal CO2 values were 5.6+/-0.8 kPa (43+/-7 mmHg) and SpO2 values were 98.3+/-1.9% with spontaneous breathing, supplemental oxygen and bite block inserted. No respiratory adverse events occurred during the 267 sedation procedures performed. CONCLUSION: Deep propofol sedation without the use of an artificial airway is an interesting technique for vacuum-assisted bite-block immobilization in young children undergoing precise radiation therapy of cranial tumors. However, simultaneous individual anesthetic challenges require pediatric anesthesiologists highly experienced with the pediatric airway, clinical alertness and closed monitoring.

Prevention of postoperative nausea and vomiting in children following adenotonsillectomy, using tropisetron with or without low-dose dexamethasone.

PURPOSE: Postoperative nausea and vomiting (PONV) after adenotonsillectomy in children is, in spite of the prophylactic administration of tropisetron, still a frequent event. The aim of this study was to evaluate the benefit of the additional systemic administration of low-dose dexamethasone (0.15 mg x kg(-1)) for the prevention of PONV. METHODS: With hospital ethics committee approval, we investigated children undergoing adenotonsillectomy receiving tropisetron (0.1 mg x kg(-1); maximum dose, 2 mg) or tropisetron (0.1 mg x kg(-1); maximum dose, 2 mg) plus dexamethasone (0.15 mg x kg(-1); maximum dose, 6 mg) intraoperatively. The incidence of vomiting episodes and the need for postoperative analgesics were recorded. Patient data were analyzed using the t-test and the chi(2) test (significance level of P = 0.05). Data values are means +/- SD. RESULTS: Ninety children (39 girls and 51 boys), aged 5.6 +/- 2.8 years and weighing 21.9 +/- 8.8 kg, were enrolled in the study. The overall incidence of vomiting was 38.9% within the first 24 h (67 vomiting events) and 44.4% within 48 h postoperatively (87 vomiting events). The incidence of vomiting in the tropisetron-only group was 53.3% (24/45) at 24 h and 60% (27/45) at 48 h (24 h: P < 0.001 and 48 h: P = 0.04) and 24.4% (11/45) at 24 h and 28.9% (13/45) at 48 h in the tropisetron-dexamethasone group. The need for postoperative nalbuphine was double in patients treated with tropisetron-dexamethasone (0.61 mg +/- 0.36 mg x kg(-1) x 48 h(-1)) compared to that in patients receiving only tropisetron (0.31 mg +/- 0.28 mg x kg(-1) x 48 h(-1); P < 0.0001). CONCLUSION: A low-dose bolus of dexamethasone (0.15 mg x kg(-1)) in combination with tropisetron, compared to tropisetron alone, considerably reduced the incidence of vomiting in children following pediatric adenotonsillectomy.

Tracheal intubation in children with Morquio syndrome using the angulated video-intubation laryngoscope.

PURPOSE: There are a number of syndromes with proven or suspected instability of the cervical spine especially in pediatric patients. It is a challenge for the anesthesiologist to intubate these patients with as little movement of the cervical spine as possible. A new device to facilitate this task is the angulated video-intubation laryngoscope (AVIL). CLINICAL FEATURES: The AVIL is a curved endoscopic intubation laryngoscope with angulated distal tip. The video-view from the distal blade tip improves glottic visualization during difficult direct laryngoscopy. We report three sisters with Morquio syndrome scheduled for otorhinolaryngology surgery the same day. Two of them had radiologically suspected cervical spine instability. Tracheal intubation was planned with careful direct laryngoscopy under manual in-line stabilization of the neck and head by an assistant. Direct visualization of the larynx using a Miller blade No. 2 was impaired in two of the three children in whom the cervical spine was immobilized. They were both successfully intubated under endoscopic control using the AVIL. CONCLUSION: The AVIL may become a helpful device to aid endotracheal intubation in patients when cervical spine immobilization impairs direct laryngoscopy.