Tadakazu Sakuragi

Growth of Escherichia coli in propofol, lidocaine, and mixtures of propofol and lidocaine

Background: Microorganisms grow rapidly in propofol. Extrinsic contamination of propofol is thought to be a source of postoperative sepsis and wound infection. We studied growth of a strain of Escherichia coli in thiopental, propofol, lidocaine, and mixtures of propofol and lidocaine.

Bactericidal activity of 0.5% bupivacaine with preservatives on microorganisms in the human skin flora.

Background and Objectives. The bactericidal activity of 0.5% bupivacaine with preservatives at body temperature and at room temperature is not known. We studied the bactericidal activity of 0.5% bupivacaine with 0.08% methyl para‐oxybenzoate and 0.02% propyl para‐aminobenzoate as preservatives and of the preservatives alone at 37°C and at room temperature on two strains of methicillin‐resistant Staphylococcus aureus, two strains of methicillin‐susceptible S. aureus, and one strain each of Staphylococcus epidermidis and Escherichia coli. Methods. The pathogen was exposed to 0.5% bupivacaine with preservatives or to the preservatives alone for 1, 3, 6, 12, and 24 hours at 37°C and at room temperature. The inocula from these suspensions were cultured for 48 hours at 37°C after the antimicrobial activity of bupivacaine was inactivated by 1:1,000 dilution with physiological saline. Results. The 1‐ through 12‐hour exposures of four strains of S. aureus to 0.5% bupivacaine with preservatives at room temperature reduced the mean colony count by 24.2%, 49.2%, 71.3%, and 89.6%, respectively, and the exposure at 37°C reduced the count by 74.1%, 95.2%, 99.9%, and 99.8%, respectively. The differences for 1‐ through 12‐hour exposures were significant (P < .001). The percentage kill in the strains of E. coli and S. epidermidis was significantly higher than that in the strains of S. aureus at all exposure times at room temperature (E. coli, P < .001; S. epidermidis, P < .0001) and at 1‐ and 3‐hour exposures at 37°C (E. coli, P < .001; S. epidermidis, P < .0001). The bactericidal activity of the preservatives was markedly lower that that of 0.5% bupivacaine with preservatives (P < .0001). Conclusions. The bactericidal activity of 0.5% bupivacaine with preservatives is stronger at body temperature than at room temperature; the bactericidal activity may be due, to a large extent, to bupivacaine rather than to the preservatives; and S. aureus is more resistant to the bactericidal activity of bupivacaine than are S. epidermidis and E. coli.

Subglottic Jet Ventilation for Pediatric Microlaryngosurgery: A Case Report

A 6-year-old girl with laryngeal papillomatosis underwent ablation of the tumors with Nd-YAG laser under microlaryngosurgery. During the surgery, she was managed with subglottic high-frequency jet ventilation using a stainless steel cannula made from a nerve block needle. It was passed through the light channel of the suspension laryngoscope and firmly affixed to it. There was no hypoxia or barotrauma to the lungs during the surgery. The postoperative course was uneventful.

Depression of evoked electromyographic (EEMG) responses by propofol in a patient with human T-cell lymphotropic virus type I-associated myelopathy (HAM)

IMPLICATIONS We report a patient with human T-cell lymphotropic virus type I-associated myelopathy. Although muscle strength in both of the upper extremities was normal in this patient, evoked electromyogram of the adductor pollicis was depressed by propofol at the induction of anesthesia.

Skin blood flow and plasma catecholamines during removal of pheochromocytoma

PREOPERATIVE α-adrenergic blockade is thought to reduce perioperative morbidity of patients undergoing removal of pheochromocytoma. 1 In addition, β-adrenergic blockade is also used to control tachycardia and dysrhythmias. However, a sudden decrease in plasma catecholamine concentrations after removal of the tumor often results in marked hypotension. 1,2 No clinical measure that reflects and monitors rapid changes occurring in plasma levels of catecholamines during manipulation of pheochromocytoma has been available yet, except for the measurement of blood pressure that reflects changes in systemic vascular resistance. Therefore, rapid fluid infusion under careful cardiovascular monitoring, immediately after ligation of adrenal veins or at removal of the tumor, has been recognized as the treatment of choice for this hypotension. 1-4 In a search for a measure that may correlate with rapidly changing plasma levels of catecholamine, we measured blood pressure, skin blood flow (SBF), and plasma catecholamine concentrations in three patients undergoing removal of pheochromocytoma. Skin blood flow in the first toe, measured by laser Doppler flowmetry, more closely followed rapid changes in plasma catecholamine concentrations than did blood pressure.

The effect of adenosine triphosphate on vecuronium-induced neuromuscular block

Continuous IV adenosine triphosphate administration has been used during surgery in the expectation of analgesic and vasodilative effects. Because adenosine triphosphate inhibits neuromuscular transmission, we investigated whether the neuromuscular effect of vecuronium was enhanced by IV adenosine triphosphate in 29 patients randomly given either continuous IV adenosine triphosphate 0.1 mg · kg−1 · min−1 or 0.9% NaCl when undergoing elective minor surgery. Anesthesia was induced and maintained with propofol. Neuromuscular monitoring was recorded from the adductor pollicis muscle using electromyography with train-of-four stimulation of the ulnar nerve. Vecuronium 25, 30, or 40 &mgr;g/kg was given and lag time, onset time, and maximum block were recorded. ED50 and ED95 values for each group were derived from least squares linear regression analysis. ED50 and ED95 values were 29 &mgr;g/kg and 44 &mgr;g/kg, respectively, for the adenosine triphosphate group and 26 &mgr;g/kg and 46 &mgr;g/kg, respectively, for the controls. Differences in lag time, onset time, and neuromuscular responses between the two groups were not statistically significant. A significantly larger number of patients in the adenosine triphosphate group showed hypotension (systolic blood pressure <80 mm Hg). Our results demonstrated that adenosine triphosphate 0.1 mg · kg−1 · min−1 did not enhance the neuromuscular block induced by vecuronium.