Tracheal intubation in a patient with undetectable tracheal narrowing on chest radiography.

We report here a 59-year-old man with a saber-sheath tracheal narrowing who was scheduled to undergo pharyngeal tumor resection under general anesthesia. The tracheal narrowing was not clearly detected by chest radiography during the preoperative examination, but it was visible on axial computed tomography (CT) images taken earlier for diagnostic purposes. Following fiber optic examination of the narrowed segment with the patient under anesthesia, the tube was inserted into the trachea using an Airway Scope. The tube was deliberately advanced into the trachea and was able to pass through the stenosis without any resistance. On postoperative radiological analysis, three-dimensional reconstruction of the trachea and virtual bronchoscopic images revealed a saber-sheath type tracheomalacia located from below the cricoid cartilage to the carina. The membranous wall had a normal width. This case indicates that chest radiographs may occasionally be inadequate for evaluating asymptomatic patients with tracheomalacia. If CT images have been taken for diagnostic purposes, they should be examined together with the chest radiograph. Digital chest radiography with edge enhancement may become a useful tool in the preoperative detection and evaluation of undetectable tracheal narrowing on conventional chest films.

[The effect of PDEIII inhibitors and colforsin daropate on hypoxic pulmonary vasoconstriction in rabbit lungs].

BACKGROUND: PDEIII inhibitors and colforsin daropate hydrochloride (CDH) exert positive inotropic and vasodilatory effects by increasing intracellular cAMP The effect of olprinone (OLP), milrinone (MIL) and CDH on hypoxic pulmonary vasoconstriction (HPV) was evaluated using isolated blood-perfused lung preparations from the rabbit in situ. METHODS: We prepared a rabbit constant-flow lung-perfusion model in which HPV was induced by decreasing the FI(O2) from 21% to 3%. We conducted 2 sets of experiments by administering different doses of OLP MIL or CDH into the reservoir. In experiment 1, we administered OLP: 0.02, 0.2, 2, 20, 200 (microg), MIL: 0.1, 1, 10, 100, 1000, or CDH: 0.01, 0.1, 1, 10, 100 (microg). In experiment 2, we administered OLP 2microg or CDH 1 microg after premedication with thapsigargin (TH) 0.1 microM. Following drug administration, changes in pulmonary artery perfusion pressure were measured. RESULTS: Experiment 1:HPV was inhibited by the administration of 200 microg OLP 100 and 1000 microg MIL, and 10 and 100 microg CDH. Experiment 2:HPV was inhibited by pretreatment with TH, although supplementation with 2 microg OLP or 1 microg CDH did not change the level of inhibition of HPV. CONCLUSIONS: These results suggest that PDEIII inhibitors and CDH inhibit HPV only at high concentrations, the mechanism of inhibition being a decrease in the sensitivity of vascular smooth muscle to Ca2+.

Anesthetic management for the minimally invasive Nuss procedure in 21 patients with pectus excavatum.

The aim of this study was to assess the anesthetic management and postoperative analgesic effect of continuous epidural infusion for the minimally invasive Nuss procedure. A total of 21 operated cases were analyzed retrospectively. Thoracoscopy was used in all cases. General anesthesia with endotracheal intubation was induced and maintained with oxygen, air, sevoflurane, and fentanyl in all cases. Thoracic epidural anesthesia was performed after induction at the level between Th4 and 12. When the bar was placed via insertion under the sternum, six patients exhibited sinus tachycardia and one showed premature atrial contraction for 2-4 beats before recovering spontaneously within 1 min. Operations were uneventful. The mean operating time was 115 min and anesthetic time was 193 min. In X-ray findings, residual pneumothorax and pleural effusion were found in seven (33.3%) and eight (38.0%) patients, respectively. In all cases, these symptoms were resolved spontaneously within 5 days. Epidural fentanyl (0.3 microg.kg(-1).h(-1)) in 0.125% bupivacaine (0.15 ml.kg(-1).h(-1)) or 0.2% ropivacaine (0.15 ml.kg(-1).h(-1)) were used for 3 days to relieve postoperative pain. Postoperatively, 12 (57.1%) patients required no additional analgesics, and 4 (19.0%) patients required a single dose of dicrofenac sodium or pentazocine. Although the Nuss procedure is minimally invasive, we should pay attention to the possibility of many intra- and postoperative complications. Continuous epidural infusion of fentanyl with local anesthetics provides effective postoperative pain relief and prevents complications such as bar displacement after the Nuss procedure.