Effects of adding epinephrine on the early systemic absorption kinetics of local anesthetics in abdominal truncal blocks.

We evaluated the pharmacokinetics of ropivacaine following rectus sheath block (RSB) and transversus abdominis plane (TAP) block with or without epinephrine. A total of 26 adult patients undergoing lower abdominal surgery with RSB (=RSB trial) and another 26 adult patients undergoing open prostatectomy with TAP block (=TAP trial) were enrolled. Patients were randomly assigned to receive either a mixture of 0.75 % ropivacaine 13.2 mL with 1 % plain lidocaine 6.8 mL (TAP-E(-) and RSB-E(-) groups) or a mixture of 0.75 % ropivacaine 13.2 mL and 1 % lidocaine containing adrenaline (1:100,000) 6.8 mL (TAP-E(+) and RSB-E(+) groups) under general anesthesia. The serum concentrations of ropivacaine were measured using gas chromatography with mass spectrometry. The peak concentration was significantly lower and time to peak concentration was significantly longer in the TAP-E(+) group than in the TAP-E(-) group (P < 0.05 and <0.01, respectively), while there were no significant differences in these parameters between the RSB-E(+) and RSB-E(-) groups. These results indicate that epinephrine attenuates the early phase of local anesthetic absorption from the injected site in TAP blocks, but not RSB.

Plasma ropivacaine concentrations after ultrasound-guided transversus abdominis plane block for open retropubic prostatectomy.

PURPOSE: Ropivacaine-induced vasoconstriction may affect the early absorption speed of ropivacaine; however, the effects of dose on pharmacokinetics following transversus abdominis plane (TAP) block have not been studied. In this study, we have examined plasma ropivacaine concentrations following TAP block with various ropivacaine concentrations (0.25, 0.5, and 0.75 %). METHODS: With the approval of our University ethics committee and informed consent, 39 adult patients undergoing open retropubic prostatectomy were enrolled. Patients were randomly assigned to three groups (n = 13 each) receiving TAP block with 20 ml (10 ml each side) of different concentrations of ropivacaine. To determine plasma concentrations, blood samples were drawn before and 15, 30, 45, 60, 90, 120, and 180 min after completion of bilateral TAP blocks. Plasma ropivacaine concentrations were analyzed by gas chromatography with mass spectrometry. RESULTS: We found that the peak plasma concentrations (C(max)) increased dose dependently (0.41 ± 0.14, 0.89 ± 0.55, and 1.56 ± 0.50 µg/ml), but the times to C(max) (23.0 ± 15.8, 23.1 ± 14.5, and 20.8 ± 11.5 min) were not different between 0.25, 0.5, and 0.75 % ropivacaine doses, respectively. Terminal elimination half-life (t(1/2)), total body clearance (CL), and distribution volume (V(d)) were also not different among the three groups. CONCLUSION: Ropivacaine concentration did not alter pharmacokinetic profile following TAP blocks.

[Anesthetic management for EXIT (ex-utero intrapartum treatment) of a twin gestation: one normal and one with a large epignathus].

We experienced cesarean section of a twin gestation of which one was normal and the other had a large epignathus. Anesthesia was induced with rapid administration of propofol and suxamethonium, then her trachea was intubated and operation was started. Anesthesia was maintained with 3% sevoflurane in 100% oxygen. Five minutes from the start of the surgery, the first baby was born with Apgar score of 3/7. One minute later, the head of the second with large epignathus was out of the uterus. But we judged that her trachea was difficult to intubate, but she showed spontaneous respiration. Then we inserted a tracheal tube (ID 2 mm) to her nose for the airway, and she was carried into the infant warmer after amputating the umbilical cord. After the delivery, sevoflurane was discontinued, and propofol, fentanyl and ketamine were started. Cesarean section was finished with total blood loss of 1,900 g including amniotic fluid. In the infant warmer, tracheostomy was performed on the second baby, and the baby was carried to NICU. Thirteen days later, the epignathus was extracted without complication. General anesthesia with inhalational agent is usually chosen for cesarean section with EXIT. For EXIT, uterine relaxation and fetal akinesia are necessary, but deep inhalational anesthesia causes massive bleeding, hypotension and loss of spontaneous respiration of the fetus. Twin gestation with one normal and the other with airway trouble has many problems. We have to consider mother, normal baby and troubled baby during EXIT. We should treat them appropriately with prudence.

Brief reports: plasma ropivacaine concentrations after ultrasound-guided rectus sheath block in patients undergoing lower abdominal surgery.

A rectus sheath block can provide postoperative analgesia for midline incisions. However, information regarding the pharmacokinetics of local anesthetics used in this block is lacking. In this study, we detail the time course of ropivacaine concentrations after this block. Thirty-nine patients undergoing elective lower abdominal surgery were assigned to 3 groups receiving rectus sheath block with 20 mL of different concentrations of ropivacaine. Peak plasma concentrations were dose dependent, and there were no significant differences in the times to peak plasma concentrations. The present data also suggested a slower absorption kinetics profile for ropivacaine after rectus sheath block than other compartment blocks.

[Case of Rett syndrome monitored with BIS and neuromuscular monitor during total intravenous anesthesia].

We describe a case of 8-year-old female patient with Rett syndrome undergoing bilateral tonsillectomy and adenotomy. She was monitored with BIS and neuromuscular monitor using TOF during total intravenous anesthesia (TIVA) with propofol, remifentanil, ketamine and rocuronium. A relatively high infusion rate of propofol (10 mg x kg x hr(-1)) was maintained to keep BIS between 60 and 70 during the surgical procedure, and rocuronium 10 mg IV was administered for tracheal intubation without its further administration during the surgical procedure. Although prolonged effects of anesthetics, analgesics and neuromuscular blockade were reported frequently, she took uneventful course during anesthesia and surgery. Her recovery from anesthesia and neuromuscular blockade was also smooth associated with satisfactory sedated states. BIS and neuromuscular monitor may be useful in TIVA for a patient with Rett syndrome.

[Anesthetic management of surgery for a huge renal tumor with the inferior vena cava invasion--application of Vigileo as a hemodynamic monitor].

In anesthetic management of surgery for a huge renal tumor with the inferior vena cava invasion, maintaining circulatory state is one of the key points. Several hemodynamic parameters are required to evaluate the circulatory state, such as central venous oxygen saturation (ScvO2), cardiac output (CO) and direct arterial blood pressure, in addition to routine hemodynamic parameters like heart rate and central venous pressure. Pulmonary artery catheter is considered as a standard apparatus to obtain those parameters; however, the catheter is invasive and may cause possible pulmonary artery damage, cardiac penetration, or severe arrhythmia. Therefore, application of pulmonary artery catheter is a relative contraindication in some cases. We used Vigileo system to obtain similar hemodynamic parameters. This system provided an arterial based pressure-based cardiac output, central venous oxygen saturation, stroke volume variation (SVV) and so on. In the present case, the system was an alternative device to pulmonary artery catheter system.

[A case of successful tracheal tube exchange with Airway Scope for tube damage during maxillo-mandibular osteotomy].

We report a case of surgical vertical-section of the nasoendotracheal tube during operation, resulting in intra-operative ventilatory difficulties. The patient was a 32-year-old female, scheduled for Maxillo-Mandibular osteotomy under general anesthesia. She was intubated with I.D. 6.0 mm non-kinking tube via left nasal cavity. Forty minutes into a maxillar osteotomy, sudden tracheal tube leak sound was noticed by surgeon. Ten more minutes later, ventilation became difficult, and laryngeal packing was done temporarily. We tried to exchange the nasotracheal tube with Airway Scope, but not with endotracheal tube exchanger, because there was a possibility of complete tube section or difficult extubation from nasal cavity. We could examine the larynx whether it was with edema or not, and two tracheal tubes at the same time. Therefore, we performed tube exchange smoothly and safely. The extubated tracheal tube had serious cut on cuff inflation line made by surgical maneuver. In the case of suspected laryngeal edema or tracheal tube injury, use of Airway Scope for tube exchange may be a safe and reliable method.