Contribution of the nasal passage to face mask ventilation: a prospective blinded randomized crossover trial.

BACKGROUND: Previous studies have shown that the nasal passage plays an important role in manual face mask ventilation, but this has yet to be quantitatively assessed. We conducted a prospective randomized crossover clinical trial to compare the change in pressure-controlled face mask tidal volume with and without nasal airway occlusion. METHOD: Female patients undergoing elective surgery under general anesthesia served as study subjects. Patients were randomly assigned to face mask ventilation beginning either with or without nasal passage occlusion (achieved with a swimmer's nose clip), followed by removal or application of the nose clip, respectively. After standardized induction of general anesthesia and muscle paralysis, a tight-fitting face mask was applied to each patient, and tidal volume was measured by the anesthesia machine during pressure-controlled ventilation (10, 15, 20 cm H2O; 8 breaths·min-1; inspiratory:expiratory ratio 1:2). RESULTS: The median [interquartile range] tidal volume was lower with vs without nasal passage occlusion at 10 cm H2O inspiratory pressure (100 [55-134] mL vs 300 [230-328] mL, respectively; median difference (MD), 200 mL; 95% confidence interval (CI), 157 to 229; P < 0.001), 15 cm H2O inspiratory pressure (190 [120-230] mL vs 520 [420-593] mL, respectively; MD, 340 mL; 95% CI, 257 to 395; P < 0.001), and 20 cm H2O inspiratory pressure (270 [215-390] mL vs 790 [713-823] mL, respectively; MD, 520 mL; 95% CI, 390 to 582; P < 0.001). CONCLUSION: Nasal passage obstruction considerably reduces tidal volume achieved during face mask ventilation. In some patients, it may be advantageous to relieve nasal airway obstruction for effective face mask ventilation. TRIAL REGISTRATION: UMIN Clinical Trials Registry, number UMIN000022184. Registered 2 May 2016.

[Anesthetic Management of Peritonectomy and Extended Operation for Peritoneal Pseudomyxoma Combined with Massive Ascites].

We report successful anesthetic management of extended operation for peritoneal pseudomyxoma combined with massive ascites (16.5 l). A 66-year-old man (weight 76 kg) who could not keep a supine position due to massive ascites associated with peritoneal pseudomyxoma was scheduled for elective peritonectomy and extended surgery. With the patient in the semisitting position, we administered 3% sevoflurane to induce loss of consciousness while preserving spontaneous ventilation. We then performed crush induction with propofol and rocuronium after topical anesthesia to the tongue base. Tracheal intubation with the Macintosh laryngoscope was successful. During the operation, we aspirated about 16.5 l of ascites over 20 l normal saline irrigation. To maintain the body temperature, we performed both active and passive extracorporeal warming. The operation included not only total peritonectomy but also distal gastrectomy, right colon resection, splenectomy, and cholecystectomy. To perform effective postoperative analgesia, we placed two epidural catheters from the upper and lower thoracic epidural spaces. The patient was extubated 3 days after operation, and discharged uneventfully on the 18th postoperative day.

Stable mononuclear radical anions of heavier group 13 elements: [(tBu2MeSi)3E.-].[K+(2.2.2-Cryptand)] (E = Al, Ga).

The one-electron reduction of tris(di-tert-butylmethylsilyl)aluminum and -gallium with alkali metals (Li, Na, K) results in the formation of the corresponding radical anions [(tBu2MeSi)3Al*-] (3) and [(tBu2MeSi)3Ga]*- (4), which were isolated in the form of the potassium salt as extremely air- and moisture-sensitive deep red crystals, representing the first isolable mononuclear radical anions of heavier group 13 elements. The molecular structures of both 3.[K+(2.2.2-cryptand)] and 4.[K+(2.2.2-cryptand)] were established by X-ray crystallography, which showed a nearly planar geometry around the radical centers. The EPR spectra of 3 and 4 showed strong characteristic signals with g-values of 2.005 for 3 and 2.015 for 4 with hyperfine coupling constants of a(27Al) = 6.2 mT for 3, a(69Ga) = 12.3 mT, and a(71Ga) = 15.7 mT for 4, corresponding to a planar geometry of the radical center.