Biomedical subjects

Toshiichiro Inagi

Publications and source records attributed to Toshiichiro Inagi.

3 recordsLinked to original sources

PubMed2005

Determining the plasma concentration of ketamine that enhances epidural bupivacaine-and-morphine-induced analgesia.

N-methyl-D-aspartate (NMDA) receptor antagonists enhance opioid-induced analgesia. The plasma concentration of ketamine, an NMDA receptor antagonist that enhances epidural morphine-and-bupivacaine-induced analgesia, is not known. We examined 24 patients with lung carcinoma or metastatic lung tumor who underwent video-assisted thoracic surgery in a placebo-controlled, double-blind manner 4 h after emergence from anesthesia. The morphine + ketamine group (n = 8) and morphine + placebo group (n = 8) received 5 mL volume of 2.5 mg morphine and 0.25% bupivacaine and the placebo + ketamine group (n = 8) received 5 mL volume of saline and 0.25% bupivacaine epidurally at the end of skin closure. Four hours after this anesthesia, in the morphine + ketamine and placebo + ketamine groups, ketamine was administered to successively maintain a stable plasma ketamine concentration of 0, 10, 20, 30, 40, and 50 ng/mL by a target-controlled infusion device, and patients assessed the levels of pain at rest, pain on coughing, somnolence (drowsiness), and nausea using a 100-mm visual analog scale (VAS). In the morphine + placebo group, a placebo (saline) was similarly administered instead of ketamine. In the morphine + ketamine group, the VAS scores for pain at rest and pain on coughing significantly decreased on ketamine administration at a plasma concentration of 20 ng/mL or larger compared with the respective baseline VAS scores (P < 0.05 each). In the placebo + ketamine group, the VAS scores for pain at rest and pain on coughing did not significantly change at any plasma concentration of ketamine as compared to the morphine + placebo group. In the morphine + ketamine group, a plasma concentration of ketamine larger than 20 ng/mL did not further reduce VAS scores for pain at rest and pain on coughing. The VAS scores for drowsiness were comparable among the three groups at any plasma concentration of ketamine. Ketamine at a plasma concentration of 20 ng/mL or larger may enhance epidural morphine-and-bupivacaine-induced analgesia. As an adjunct with epidural morphine-and-bupivacaine and considering the safety of small doses, the minimal plasma concentration of ketamine given IV may be approximately 20 ng/mL.

Adult↗

PubMed2004

Unanticipated hemothorax during general anesthesia.

We experienced a case of uncommon spontaneous hemothorax during general anesthesia. A 72-year-old woman underwent emergency repair of damaged ascending colon. Her chest roentgenogram before surgery revealed no abnormalities. After the uneventful surgery, the trachea was extubated and the patient breathed without difficulty with stable vital signs. However, the S(p)(O)(2) varied around 95% with a 100% oxygen mask. Chest roentgenogram obtained after extubation showed a massive amount of fluid in the pleural cavity. A chest drainage tube was inserted, and approximately 1000 ml of frank blood was drawn without air leakage. Thereafter, her oxygenation remarkably improved. We could not determine the etiology of the hemothorax.

Aged↗

PubMed2003

Pregnancy-related increases in sensory perception thresholds are not correlated with serum progesterone levels.

BACKGROUND: Why pregnant women require smaller doses of anesthetic agents still remains speculative. One hypothesis proposes that pregnancy raises sensory perception thresholds, perhaps through a progesterone-mediated effect. This study was undertaken in order to quantify any changes in sensory perception thresholds after parturition and to correlate these changes with the expected decrease in postpartum serum progesterone levels. METHODS: Nineteen gravid women scheduled to undergo an elective Cesarean section consented to participate. Sensory current perception threshold (CPT) testing was performed before and 7 days after an elective Cesarean section. CPT was defined as the minimum amount of constant current stimulation that can be reproducibly detected at a particular frequency. CPT values were determined on the distal phalanx of the nondominant index finger at 2000 Hz, 250 Hz, and 5 Hz monofrequency stimulation. Seven women permitted serum progesterone level determinations at the prepartum and the postpartum CPT testing sessions. RESULTS: Parturition resulted in a statistically significant decrease in the sensory CPT at all 3 frequencies tested, (p < 0.05). However, there was no significant correlation between the postpartum reduction in serum progesterone levels and the observed postpartum decrease in CPT for any frequency, (r < 0.5). CONCLUSIONS: CPTs are significantly reduced after parturition. However, this reduction does not appear to be significantly correlated with the reduction in serum progesterone levels.

Journal Article↗