Biomedical subjects
Publications and source records attributed to Nobuhiro Matsuoka.
It has been reported that a unipolar pacemaker is more sensitive to electromagnetic interference (EMI) than a bipolar pacemaker. However, we experienced cases in which electrosurgery device interfered with a bipolar pacemaker, but not with a unipolar pacemaker during TUR-P. It has been suggested that EMI occurs to a bipolar pacemaker depending on sensitivity and electric resistance of a patient.
It is reported that ropivacaine, a new amide-linked local anesthetic, can be used safely in patients susceptible to malignant hyperthermia. We report a case of the use of epidural ropivacaine for a gravida with disposition for malignant hyperthermia. A 33-year-old female patient, 11 weeks and 2 days pregnant, was admitted for torsion of the right ovarian cyst. Five years before, she had been prepared for operation for uterine myoma. After premedication with atropine 0.5 mg and hydroxyzine 50 mg i.m. her body temperature increased to 39.0 degrees C, and the operation was postponed. By muscle biopsy she was diagnosed susceptible to malignant hyperthermia. Two months thereafter, the operation for uterine myoma was performed under epidural lidocaine and intravenous propofol anesthesia. Three years ago, she had cesarean section under epidural anesthesia using mepivacaine. This time, the epidural catheter was inserted at L 3-4 interspace, and 10 ml of 1.0% ropivacaine was administrated. After fifteen minutes analgesia was obtained to T 10-L 2. Forty minutes later the operation was performed and the patient was safely anesthetized by ropivacaine. Later at 37 weeks and 3 days pregnancy, cesarean section was performed with epidural ropivacaine.
UNLABELLED: Although a nitrous oxide (N(2)O) gas-barrier cuff effectively limits the increase of cuff pressure during N(2)O anesthesia, there are few data assessing whether an N(2)O gas-barrier cuff is more beneficial for stabilizing intracuff pressure than standard endotracheal tubes when cuffs are repeatedly deflated to stabilize pressure during N(2)O anesthesia. In the present study, the pressure of air-filled standard-type cuffs (Trachelon; Terumo, Tokyo, Japan) and N(2)O gas-barrier type endotracheal tube cuffs (Profile Soft-Seal Cuff [PSSC]; Sims Portex, Kent, UK) was measured during 67% N(2)O anesthesia (n = 8 in each), during which the cuffs were repeatedly deflated every 30 min (Trachelon) or 60 min (PSSC) for the first 3 or 4 h. After aspirating the cuffs for 3 h, the cuff pressure exceeded 22 mm Hg in more than half of the patients in both groups. However, aspiration of the cuffs for 4 h decreased the maximal cuff pressure between deflation intervals in both groups (P < 0.01 for each), and increased the intracuff N(2)O concentration (P < 0.0001 for each). After deflating the cuffs over 4 h, the cuff pressure in both groups never exceeded 22 mm Hg during the subsequent 3 h, and intracuff N(2)O concentrations did not significantly change. Therefore, deflation of cuffs for 4 h during N(2)O anesthesia sufficiently stabilized cuff pressure and equilibrated the intracuff N(2)O concentrations in both groups. The use of the PSSC endotracheal tube might be more practical because of the smaller number of cuff deflations required, but the PSSC does not reduce the duration of cuff deflations to stabilize the pressure. IMPLICATIONS: We demonstrated that the N(2)O concentration and pressure in the N(2)O-barrier Profile Soft-Seal Cuff stabilized when the cuff was aspirated once an hour for 4 h during N(2)O anesthesia. The Profile Soft-Seal Cuff might be easier to use in clinical practice than standard endotracheal tubes because of the smaller number of cuff deflations required.